1.
Monclova
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Santiago de la Monclova, more commonly known as Monclova, is a city and seat of the surrounding municipality of the same name in the northern Mexican state of Coahuila. According to the 2015 INEGI census there were 231,107 inhabitants in the city and 231,107 in the municipality and its metropolitan area has 363,753 inhabitants and has a population density of 29.88 inhabitants per square kilometers. Monclova is the third largest city in Coahuila, established on July 25,1577, Monclova became the first city in the region known as Coahuila, and later known as the State of Coahuila. During the colonial period and the first years of the 19th century and it remained the capital during the early years of Mexicos independence. The captured leaders were Juan Aldama, Ignacio Allende, Miguel Hidalgo, with the adoption of the 1824 Constitution, which created the state of Coahuila y Tejas, the capital was transferred to Saltillo. In 1828 this decision was overturned when Monclova was declared the capital of the new state, on March 9,1833, the state legislature settled the dispute in Monclovas favour, and this decision was ratified by President Antonio López de Santa Anna on December 2,1834. However, 1835-36 was also the period of the Texas Revolution, Monclova sits at an altitude of 600m above sea level, but over the years the sand sediments of the city have sunk it 8 meters below the original level due to the weight of constructions. It is located at 26°54′37″N 101°25′20″W, in the central region. Monclova experiences a warm climate, with a median yearly temperature of 22.0 °C. The median temperature of the coolest month, January, is 13.6 °C, although the temperature can climb as high as 30 °C during some days and it can drop0 °C some nights and mornings. In the 1970s the coolest temperature recorded was −4.2 °C on February 9,1973, in the 1990s the same value was recorded on January 13,1997. Since 2000 the lowest recorded was −2 °C on January 17,2007, probably the coldest snap in recent history took place on Christmas Day 1983, when the citys temperature plunged to −9.5 °C. On the other hand, temperatures during spring and summer can have bouts of extreme heat. In recent decades the hottest records have climbed as high as 43 °C on July 13,2005 and 45 °C on May 4,1984, however nighttime low temperatures are typically 15 degrees cooler than daytime highs, due to the very arid conditions. Even in July, the warmest month, temperatures have gotten as low as 10.6 °C in 1975, the median temperature July is 28.6 °C. A typical summer day has a low around 21 °C and a high near 35 °C. In 1976 the wettest month on record took place in July, with 287.3 mm of rain, more than half the yearly value of 376.7 mm. The warmer months of the year are typically wetter than the cooler ones, cold fronts in winter have the possibility of drastically reducing temperatures in the area, and are responsible for the little rainfall of such period
2.
Metallurgy
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The production of metals involves the processing of ores to extract the metal they contain, and the mixture of metals, sometimes with other elements, to produce alloys. Metallurgy is distinguished from the craft of metalworking, although metalworking relies on metallurgy, as medicine relies on medical science, Metallurgy is subdivided into ferrous metallurgy and non-ferrous metallurgy or colored metallurgy. Ferrous metallurgy involves processes and alloys based on iron while non-ferrous metallurgy involves processes, the production of ferrous metals accounts for 95 percent of world metal production. The roots of metallurgy derive from Ancient Greek, μεταλλουργός, metallourgós, worker in metal, from μέταλλον, métallon, metal + ἔργον, érgon, in the late 19th century it was extended to the more general scientific study of metals, alloys, and related processes. In English, the pronunciation is the more common one in the UK. The /ˈmetələrdʒi/ pronunciation is the common one in the USA. The earliest recorded metal employed by humans appears to be gold, small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c.40,000 BC. Silver, copper, tin and meteoric iron can also be found in native form, egyptian weapons made from meteoric iron in about 3000 BC were highly prized as daggers from heaven. Certain metals, notably tin, lead and copper, can be recovered from their ores by simply heating the rocks in a fire or blast furnace, a process known as smelting. The first evidence of this extractive metallurgy dates from the 5th and 6th millennia BC and was found in the sites of Majdanpek, Yarmovac and Plocnik. To date, the earliest evidence of copper smelting is found at the Belovode site, other signs of early metals are found from the third millennium BC in places like Palmela, Los Millares, and Stonehenge. However, the ultimate beginnings cannot be ascertained and new discoveries are both continuous and ongoing. These first metals were single ones or as found, about 3500 BC, it was discovered that by combining copper and tin, a superior metal could be made, an alloy called bronze, representing a major technological shift known as the Bronze Age. The extraction of iron from its ore into a metal is much more difficult than for copper or tin. The process appears to have been invented by the Hittites in about 1200 BC, the secret of extracting and working iron was a key factor in the success of the Philistines. Historical developments in ferrous metallurgy can be found in a variety of past cultures. A 16th century book by Georg Agricola called De re metallica describes the highly developed and complex processes of mining metal ores, metal extraction, Agricola has been described as the father of metallurgy. Extractive metallurgy is the practice of removing valuable metals from an ore, in order to convert a metal oxide or sulphide to a purer metal, the ore must be reduced physically, chemically, or electrolytically
3.
Furnace
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A furnace is a device used for high-temperature heating. The name derives from Greek word fornax, which means oven, the heat energy to fuel a furnace may be supplied directly by fuel combustion, by electricity such as the electric arc furnace, or through induction heating in induction furnaces. Furnace may also be a synonym for kiln, a used in the production of ceramics. Furnaces can be classified into four categories, based on efficiency. The first category would be natural draft, atmospheric burner furnaces and these furnaces consisted of cast-iron or riveted-steel heat exchangers built within an outer shell of brick, masonry, or steel. The heat exchangers were vented through brick or masonry chimneys, air circulation depended on large, upwardly pitched pipes constructed of wood or metal The pipes would channel the warm air into floor or wall vents inside the home. This method of heating worked because warm air rises, the system was simple, had few controls, a single automatic gas valve, and no blower. These furnaces could be made to work with any fuel simply by adapting the burner area and they have been operated with wood, coke, coal, trash, paper, natural gas, and fuel oil. Furnaces that used solid fuels required daily maintenance to remove ash, in later years, these furnaces were adapted with electric blowers to aid air distribution and speed moving heat into the home. The second category of furnace is the forced-air, atmospheric burner style with a cast-iron or sectional steel heat exchanger. Through the 1950s and 1960s, this style of furnace was used to replace the big, natural draft systems, the heated air was moved by blowers which were belt driven and designed for a wide range of speeds. These furnaces were still big and bulky compared to modern furnaces, energy efficiency would range anywhere from just over 50% to upward of 65% AFUE. This style furnace still used large, masonry or brick chimneys for flues and was designed to accommodate air-conditioning systems. The third category of furnace is the draft, mid-efficiency furnace with a steel heat exchanger. These furnaces were physically much more compact than the previous styles and they were equipped with combustion air blowers that would pull air through the heat exchanger which greatly increased fuel efficiency while allowing the heat exchangers to become smaller. These furnaces may have multi-speed blowers and were designed to work with central air-conditioning systems, the fourth category of furnace is the high-efficiency, or condensing furnace. High-efficiency furnaces can achieve from 89% to 98% fuel efficiency and this style of furnace includes a sealed combustion area, combustion draft inducer and a secondary heat exchanger. Because the heat exchanger removes most of the heat from the exhaust gas, it actually condenses water vapor, the vent pipes are normally installed with PVC pipe versus metal vent pipe to prevent corrosion
4.
Smelting
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Smelting is a form of extractive metallurgy, its main use is to produce a base metal from its ore. This includes production of silver, iron, copper and other metals from their ores. Smelting makes use of heat and a reducing agent to decompose the ore, driving off other elements as gases or slag. The reducing agent is commonly a source of such as coke. The carbon removes oxygen from the ore, leaving behind the elemental metal, the carbon is thus oxidized in two stages, producing first carbon monoxide and then carbon dioxide. As most ores are impure, it is necessary to use flux, such as limestone. Plants for the reduction of aluminium are also generally referred to as aluminium smelters. Smelting involves more than just melting the metal out of its ore, most ores are a chemical compound of the metal with other elements, such as oxygen, sulfur or carbon and oxygen together. To produce the metal, these compounds have to undergo a chemical reaction, smelting therefore consists of using suitable reducing substances that will combine with those oxidizing elements to free the metal. In the case of carbonates and sulfides, a process called roasting drives out the carbon or sulfur, leaving an oxide. Roasting is usually carried out in an oxidizing environment, a few practical examples, Malachite, a common ore of copper, is primarily copper carbonate hydroxide Cu22. This mineral undergoes thermal decomposition to 2CuO, CO2, and H2O in several stages between 250 °C and 350 °C, the carbon dioxide and water are expelled into the atmosphere, leaving copper oxide which can be directly reduced to copper as described in the following section titled Reduction. Galena, the most common mineral of lead, is primarily lead sulfide, the sulfide is oxidized to a sulfite which thermally decomposes into lead oxide and sulfur dioxide gas. The sulfur dioxide is expelled, and the oxide is reduced as below. Reduction is the final, high-temperature step in smelting and it is here that the oxide becomes the elemental metal. A reducing environment pulls the final oxygen atoms from the raw metal, the required temperature varies over a very large range, both in absolute terms and in terms of the melting point of the base metal. Fluxes are used in smelting for several purposes, chief among them catalyzing the desired reactions, of the seven metals known in antiquity, only gold occurred regularly in native form in the natural environment. The others – copper, lead, silver, tin, iron and mercury – occur primarily as minerals and these minerals are primarily carbonates, sulfides, or oxides of the metal, mixed with other components such as silica and alumina
5.
Pig iron
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Pig iron is an intermediate product of the iron industry. Pig iron is made by smelting iron ore into an ingot of impure high carbon-content iron in a blast furnace as an ingredient for further processing steps. When the metal had cooled and hardened, the ingots were simply broken from the runner. As pig iron is intended for remelting, the size of the ingots. Smelting and producing pig iron and other products was known to the Ancient Egyptians. The Roman Empire and later the Muslim caliphates of the Middle Ages inherited and refined these technologies, because of the collapse of the Western Roman Empire, Western Europe did not rediscover the process until the Late Middle Ages. The phase transition of the iron into liquid in the furnace was an avoided phenomenon, the Chinese were also making pig iron by the later Zhou Dynasty. Traditionally pig iron was worked into wrought iron in forges, later puddling furnaces. In these processes, pig iron is melted and a current of air is directed over it while it is stirred or agitated. This causes the dissolved impurities to be thoroughly oxidized, an intermediate product of puddling is known as refined pig iron, finers metal, or refined iron. Pig iron can also be used to produce gray iron and this is achieved by remelting pig iron, often along with substantial quantities of steel and scrap iron, removing undesirable contaminants, adding alloys, and adjusting the carbon content. Some pig iron grades are suitable for producing ductile iron and these are high purity pig irons and depending on the grade of ductile iron being produced these pig irons may be low in the elements silicon, manganese, sulfur and phosphorus. These types of pig irons are used to all the elements in a ductile iron charge which may be harmful to the ductile iron process. Earlier processes for this included the finery forge, the furnace, the Bessemer process. Modern pig casting machines produce stick pigs, which break into smaller 4–10 kg piglets at discharge
6.
Lead
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Lead is a chemical element with atomic number 82 and symbol Pb. When freshly cut, it is bluish-white, it tarnishes to a dull gray upon exposure to air and it is a soft, malleable, and heavy metal with a density exceeding that of most common materials. Lead has the second-highest atomic number of the stable elements. Lead is a relatively unreactive post-transition metal and its weak metallic character is illustrated by its amphoteric nature and tendency to form covalent bonds. Compounds of lead are found in the +2 oxidation state. Exceptions are mostly limited to organolead compounds, like the lighter members of the group, lead exhibits a tendency to bond to itself, it can form chains, rings, and polyhedral structures. Lead is easily extracted from its ores and was known to people in Western Asia. A principal ore of lead, galena, often bears silver, Lead production declined after the fall of Rome and did not reach comparable levels again until the Industrial Revolution. Nowadays, global production of lead is about ten million tonnes annually, Lead has several properties that make it useful, high density, low melting point, ductility, and relative inertness to oxidation. In the late 19th century, lead was recognized as poisonous, Lead is a neurotoxin that accumulates in soft tissues and bones, damaging the nervous system and causing brain disorders and, in mammals, blood disorders. A lead atom has 82 electrons, arranged in a configuration of 4f145d106s26p2. The combined first and second ionization energies—the total energy required to remove the two 6p electrons—is close to that of tin, leads upper neighbor in group 14. This is unusual since ionization energies generally fall going down a group as an elements outer electrons become more distant from the nucleus, the similarity is caused by the lanthanide contraction—the decrease in element radii from lanthanum to lutetium, and the relatively small radii of the elements after hafnium. The contraction is due to shielding of the nucleus by the lanthanide 4f electrons. The combined first four ionization energies of lead exceed those of tin, for this reason lead, unlike tin, mostly forms compounds in which it has an oxidation state of +2, rather than +4. Relativistic effects, which become particularly prominent at the bottom of the periodic table, as a result, the 6s electrons of lead become reluctant to participate in bonding, a phenomenon called the inert pair effect. A related outcome is that the distance between nearest atoms in crystalline lead is unusually long, the lighter group 14 elements form stable or metastable allotropes having the tetrahedrally coordinated and covalently bonded diamond cubic structure. The energy levels of their outer s- and p-orbitals are close enough to allow mixing into four hybrid sp3 orbitals
7.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
8.
Coke (fuel)
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Coke is a fuel with few impurities and a high carbon content, usually made from coal. It is the carbonaceous material derived from destructive distillation of low-ash. Cokes made from coal are grey, hard, and porous, while coke can be formed naturally, the commonly used form is man-made. The form known as coke, or pet coke, is derived from oil refinery coker units or other cracking processes. Coke is used in preparation of producer gas which is a mixture of carbon monoxide, producer gas is produced by passing air over red-hot coke. Coke is also used to water gas. Historical sources dating to the 4th century describe the production of coke in ancient China, the Chinese first used coke for heating and cooking no later than the ninth century. By the first decades of the century, Chinese ironworkers in the Yellow River valley began to fuel their furnaces with coke. In 1589 a patent was granted to Thomas Proctor and William Peterson for making iron and steel and melting lead with earth-coal, sea-coal, turf, the patent contains a distinct allusion to the preparation of coal by cooking. In 1590 a patent was granted to the Dean of York to purify pit-coal, in 1620 a patent was granted to a company composed of William St. John, Robert Follensbee and other knights, mentioning the use of coke in smelting ores and manufacturing metals. In 1627 a patent was granted to Sir John Hacket and Octavius de Strada for a method of rendering sea-coal and pit-coal as useful as charcoal for burning in houses, without offense by smell or smoke. In 1603 Hugh Plat suggested that coal might be charred in an analogous to the way charcoal is produced from wood. In 1709 Abraham Darby I established a coke-fired blast furnace to produce cast iron, cokes superior crushing strength allowed blast furnaces to become taller and larger. The ensuing availability of iron was one of the factors leading to the Industrial Revolution. Before this time, iron-making used large quantities of charcoal, produced by burning wood, in the late 18th century, brick beehive ovens were developed, which allowed more control over the burning process. In 1768 John Wilkinson built a more practical oven for converting coal into coke, with greater skill in the firing, covering and quenching of the heaps, yields were increased from about 33 per cent to 65 per cent by the middle of the 19th century. The Scottish iron industry expanded rapidly in the second quarter of the 19th century. In 1802 a battery of beehives was set up near Sheffield, by 1870, there were 14,000 beehive ovens in operation on the West Durham coalfields, capable of producing 4.2 million tons of coke
9.
Ore
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An ore is a type of rock that contains sufficient minerals with important elements including metals that can be economically extracted from the rock. The ores are extracted from the earth through mining, they are refined to extract the valuable element. The grade or concentration of an ore mineral, or metal, as well as its form of occurrence, will directly affect the costs associated with mining the ore. The cost of extraction must thus be weighed against the value contained in the rock to determine what ore can be processed. Metal ores are generally oxides, sulfides, silicates, or native metals that are not commonly concentrated in the Earths crust, the ores must be processed to extract the metals of interest from the waste rock and from the ore minerals. Ore bodies are formed by a variety of geological processes, the process of ore formation is called ore genesis. An ore deposit is an accumulation of ore and this is distinct from a mineral resource as defined by the mineral resource classification criteria. An ore deposit is one occurrence of a particular ore type, Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. Stratiform arkose-hosted and shale-hosted copper, typified by the Zambian copperbelt and this identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work. This is because the distribution of ores is unequal and dislocated from locations of peak demand. Other, lesser, commodities do not have international clearing houses and benchmark prices and this generally makes determining the price of ores of this nature opaque and difficult. Such metals include lithium, niobium-tantalum, bismuth, antimony and rare earths, most of these commodities are also dominated by one or two major suppliers with >60% of the worlds reserves. The London Metal Exchange aims to add uranium to its list of metals on warrant, the World Bank reports that China was the top importer of ores and metals in 2005 followed by the USA and Japan. Economic geology Mineral resource classification Ore genesis Petrology Froth Flotation Extractive metallurgy DILL, the “chessboard” classification scheme of mineral deposits, Mineralogy and geology from aluminum to zirconium, Earth-Science Reviews, Volume 100, Issue 1-4, June 2010, Pages 1-420
10.
Flux (metallurgy)
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In metallurgy, a flux is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time and they are used in both extractive metallurgy and metal joining. Some of the earliest known fluxes were carbonate of soda, potash, charcoal, coke, borax, lime, lead sulfide, iron ore was also used as a flux in the smelting of copper. As cleaning agents, fluxes facilitate soldering, brazing, and welding by removing oxidation from the metals to be joined, the slag is a liquid mixture of ash, flux, and other impurities. This reduction of slag viscosity with temperature, increasing the flow of slag in smelting, is the origin of the word flux in metallurgy. Fluxes are also used in foundries for removing impurities from molten nonferrous metals such as aluminium, in high-temperature metal joining processes, the primary purpose of flux is to prevent oxidation of the base and filler materials. Tin-lead solder attaches very well to copper, but poorly to the oxides of copper. Flux is a substance which is inert at room temperature. Additionally, flux allows solder to flow easily on the piece rather than forming beads as it would otherwise. In some applications molten flux also serves as a heat transfer medium, fluxes for soft soldering are typically of organic nature, though inorganic fluxes, usually based on halogenides and/or acids, are also used in non-electronics applications. Fluxes for brazing operate at higher temperatures and are therefore mostly inorganic. Organic fluxes typically consist of four components, Activators - chemicals disrupting/dissolving the metal oxides. Their role is to expose unoxidized, easily wettable metal surface and aid soldering by other means, highly active fluxes contain chemicals that are corrosive at room temperature. The compounds used include metal halides, hydrochloric acid, phosphoric acid, Salts of mineral acids with amines are also used as aggressive activators. Aggressive fluxes typically facilitate corrosion, require careful removal, and are unsuitable for finer work, Activators for fluxes for soldering and brazing aluminium often contain fluorides. Milder activators begin to react with oxides only at elevated temperature, typical compounds used are carboxylic acids and sometimes amino acids. Some milder fluxes also contain halides or organohalides, vehicles - high-temperature tolerant chemicals in the form of non-volatile liquids or solids with suitable melting point, they are generally liquid at soldering temperatures. Solid vehicles tend to be based on natural or modified rosin or natural or synthetic resins, water-soluble organic fluxes tend to contain vehicles based on high-boiling polyols - glycols, diethylene glycol and higher polyglycols, polyglycol-based surfactants and glycerol
11.
Atmosphere of Earth
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The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earths gravity. The atmosphere of Earth protects life on Earth by absorbing solar radiation, warming the surface through heat retention. By volume, dry air contains 78. 09% nitrogen,20. 95% oxygen,0. 93% argon,0. 04% carbon dioxide, and small amounts of other gases. Air also contains an amount of water vapor, on average around 1% at sea level. The atmosphere has a mass of about 5. 15×1018 kg, the atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km, or 1. 57% of Earths radius, is used as the border between the atmosphere and outer space. Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km, several layers can be distinguished in the atmosphere, based on characteristics such as temperature and composition. The study of Earths atmosphere and its processes is called atmospheric science, early pioneers in the field include Léon Teisserenc de Bort and Richard Assmann. The three major constituents of air, and therefore of Earths atmosphere, are nitrogen, oxygen, water vapor accounts for roughly 0. 25% of the atmosphere by mass. The remaining gases are often referred to as gases, among which are the greenhouse gases, principally carbon dioxide, methane, nitrous oxide. Filtered air includes trace amounts of other chemical compounds. Various industrial pollutants also may be present as gases or aerosols, such as chlorine, fluorine compounds, sulfur compounds such as hydrogen sulfide and sulfur dioxide may be derived from natural sources or from industrial air pollution. In general, air pressure and density decrease with altitude in the atmosphere, however, temperature has a more complicated profile with altitude, and may remain relatively constant or even increase with altitude in some regions. In this way, Earths atmosphere can be divided into five main layers, excluding the exosphere, Earth has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km where it merges into the solar wind. This layer is composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another, thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may migrate in and out of the magnetosphere or the solar wind, the exosphere is located too far above Earth for any meteorological phenomena to be possible
12.
Oxygen
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Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the group on the periodic table and is a highly reactive nonmetal. By mass, oxygen is the third-most abundant element in the universe, after hydrogen, at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20. 8% of the Earths atmosphere, additionally, as oxides the element makes up almost half of the Earths crust. Most of the mass of living organisms is oxygen as a component of water, conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone, strongly absorbs ultraviolet UVB radiation, but ozone is a pollutant near the surface where it is a by-product of smog. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft, the name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle, Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philos work by observing that a portion of air is consumed during combustion and respiration, Oxygen was discovered by the Polish alchemist Sendivogius, who considered it the philosophers stone. In the late 17th century, Robert Boyle proved that air is necessary for combustion, English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. From this he surmised that nitroaereus is consumed in both respiration and combustion, Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract De respiratione. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, one part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the combustion products
13.
Tuyeres
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A tuyere or tuyère is a tube, nozzle or pipe through which air is blown into a furnace or hearth. Air or oxygen is injected into a hearth under pressure from bellows or an engine or other devices. This causes the fire to be hotter in front of the blast than it would otherwise have been and this applies to any process where a blast is delivered under pressure to make a fire hotter. The term was introduced to England from French with the new technology of the blast furnace and finery forge in around 1500, following the introduction of hot blast, tuyeres are often water-cooled. A bloomery normally had one tuyere, early blast furnaces also had one tuyere, but were fed from bellows perhaps 12 feet long operated by a waterwheel. During the Industrial Revolution, the blast began to be provided using steam engines, improvements in foundry practice enabled gas-tight cast iron pipes to be produced, enabling one engine to deliver blast to several sides of a furnace, through multiple tuyeres. A finery forge contained finery and chafery hearths, usually one of the latter, each hearth was equipped with its own set of bellows, blowing into it through a tuyere. The blacksmiths hearth at their forge has a tuyere, often blown by foot-operated bellows, tuyeres were also used in smelting lead and copper in smeltmills. Modern blast furnaces may have up to 42 tuyeres, through which the hot blast is injected in the furnace and they are usually made from copper and cooled with a water jacket to withstand the extreme temperatures
14.
Blast furnace
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A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron, but also others such as lead or copper. The end products are usually molten metal and slag phases tapped from the bottom, the downward flow of the ore and flux in contact with an upflow of hot, carbon monoxide-rich combustion gases is a countercurrent exchange and chemical reaction process. In contrast, air furnaces are naturally aspirated, usually by the convection of hot gases in a chimney flue, according to this broad definition, bloomeries for iron, blowing houses for tin, and smelt mills for lead would be classified as blast furnaces. Blast furnaces existed in China from about 1st century AD and in the West from the High Middle Ages and they spread from the region around Namur in Wallonia in the late 15th century, being introduced to England in 1491. The fuel used in these was invariably charcoal, the successful substitution of coke for charcoal is widely attributed to Abraham Darby in 1709. The efficiency of the process was enhanced by the practice of preheating the combustion air. The oldest extant blast furnaces were built during the Han Dynasty of China in the 1st century AD. However, cast iron tools and weapons were widespread in China by the 5th century BC. These early furnaces had clay walls and used phosphorus-containing minerals as a flux, the effectiveness of the Chinese blast furnace was enhanced during this period by the engineer Du Shi, who applied the power of waterwheels to piston-bellows in forging cast iron. He suggests that early blast furnace and cast iron production evolved from furnaces used to melt bronze, certainly, though, iron was essential to military success by the time the State of Qin had unified China. Usage of the blast and cupola furnace remained widespread during the Song and Tang Dynasties and this may have happened as early as the 4th century AD. The Chinese blast furnace remained in use well until the 20th century, the backyard furnaces favoured by Mao Zedong during the Great Leap Forward were of this type. In the regions with strong traditions of metallurgy, the production actually increased during this period. In most places in the other than in China, there is no evidence of the use of the blast furnace. Instead, iron was made by reduction in bloomeries. The bloomery process was invented probably in modern-day Xinjiang or other parts of Western China by Hans or Mongols around 800 BC. Iron finds in China proper are few before bloomeries were supplanted by the blast furnace in the 5th century BC which seems to have developed independently in the southern Chinese cultural sphere, in Europe, the Greeks, Celts, Romans, and Carthaginians all used this process. Several examples have found in France, and materials found in Tunisia suggest they were used there as well as in Antioch during the Hellenistic Period
15.
Metal
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A metal is a material that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium, platinum and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades. The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
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Slag
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Slag is the glass-like by-product left over after a desired metal has been separated from its raw ore. Slag is usually a mixture of oxides and silicon dioxide. However, slags can contain metal sulfides and elemental metals, in nature, iron, copper, lead, nickel and other metals are found in impure states called ores, often oxidized and mixed in with silicates of other metals. During smelting, when the ore is exposed to high temperatures, Slag is the collection of compounds that are removed. In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities, in this case, the slag is termed synthetic. Ferrous and non-ferrous smelting processes produce different slags, the smelting of copper and lead in non-ferrous smelting, for instance, is designed to remove the iron and silica that often occurs with those ores, and separates them as iron-silicate-based slags. Slag from steel mills in ferrous smelting, on the hand, is designed to minimize iron loss and so mainly contains oxides of calcium, silicon, magnesium. Any sandy component or quartz component of the original ore automatically carries through the process as silicon dioxide. As the slag is channeled out of the furnace, water is poured over it and this rapid cooling, often from a temperature of around 2,600 °F, is the start of the granulating process. This process causes several chemical reactions to take place within the slag, the water carries the slag in its slurry format to a large agitation tank, from where it is pumped along a piping system into a number of gravel based filter beds. The filter beds then retain the slag granules, while the drains away and is returned to the system. During the Bronze Age of the Mediterranean there were a vast number of metallurgical processes in use. A slag by-product of such workings was a colorful, glassy and it was primarily blue or green and was formerly chipped away and melted down to make glassware products and jewelry. It was also ground into powder to add to glazes for use in ceramics, some of the earliest such uses for the by-products of slag have been found in ancient Egypt. Historically, the re-smelting of iron ore slag was common practice, during the early 20th century, iron ore slag was also ground to a powder and used to make agate glass, also known as slag glass. Ground granulated slag is used in concrete in combination with Portland cement as part of a blended cement. Ground granulated slag reacts with water to produce cementitious properties, concrete containing ground granulated slag develops strength over a longer period, leading to reduced permeability and better durability. Since the unit volume of Portland cement is reduced, this concrete is less vulnerable to alkali-silica, the slag can also be used to create fibers used as an insulation material called slag wool
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Flue gas
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Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants. Its composition depends on what is being burned, but it will usually consist of mostly nitrogen derived from the combustion of air, carbon dioxide, and water vapor as well as excess oxygen. It further contains a percentage of a number of pollutants, such as particulate matter, carbon monoxide, nitrogen oxides. At power plants, flue gas is often treated with a series of processes and scrubbers. Electrostatic precipitators or fabric filters remove particulate matter and flue-gas desulfurization captures the sulfur dioxide produced by burning fossil fuels, nitrogen oxides are treated either by modifications to the combustion process to prevent their formation, or by high temperature or catalytic reaction with ammonia or urea. In either case, the aim is to produce nitrogen gas, such scrubbing can lead to meaningful recovery of sulfur for further industrial use. Technologies based on regenerative capture by amines for the removal of CO2 from flue gas have been deployed to provide high purity CO2 gas to the food industry, and for enhanced oil recovery. They are now active research as a method for CO2 capture for long-term storage as a means of greenhouse gas remediation. There are a number of technologies for removing pollutants emitted from power plants that are now available. There is also much ongoing research into technologies that will even more air pollutants. Carbon capture and storage Emission standard Exhaust gas Flue-gas emissions from fossil-fuel combustion Flue gas stacks Integrated gasification combined cycle Landfill gas
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Countercurrent exchange
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The flowing bodies can be liquids, gases, or even solid powders, or any combination of those. For example, in a column, the vapors bubble up through the downward flowing liquid while exchanging both heat and mass. The maximum amount of heat or mass transfer that can be obtained is higher with countercurrent than co-current exchange because countercurrent maintains a slowly declining difference or gradient, in cocurrent exchange the initial gradient is higher but falls off quickly, leading to wasted potential. For example, in the diagram at the right, the fluid being heated has a higher exiting temperature than the fluid that was used for heating. With cocurrent or parallel exchange the heated and cooled fluids can only approach one another, the result is that countercurrent exchange can achieve a greater amount of heat or mass transfer than parallel under otherwise similar conditions. Countercurrent exchange when set up in a circuit or loop can be used for building up concentrations, heat, Countercurrent exchange circuits or loops are found extensively in nature, specifically in biologic systems. In vertebrates, they are called a rete mirabile, originally the name of an organ in fish gills for absorbing oxygen from the water and it is mimicked in industrial systems. Countercurrent exchange is a key concept in chemical engineering thermodynamics and manufacturing processes, Countercurrent multiplication is a similar but different concept where liquid moves in a loop followed by a long length of movement in opposite directions with an intermediate zone. Countercurrent multiplication has been found in the kidneys as well as in other biological organs. The property transferred could be heat, concentration of a chemical substance, when heat is transferred, a thermally-conductive membrane is used between the two tubes, and when the concentration of a chemical substance is transferred a semipermeable membrane is used. In the cocurrent flow exchange mechanism, the two fluids flow in the same direction, as the Cocurrent and countercurrent exchange mechanisms diagram showed, a cocurrent exchange system has a variable gradient over the length of the exchanger. With equal flows in the two tubes, this method of exchange is only capable of moving half of the property from one flow to the other, no matter how long the exchanger is. In the case of unequal flows, the condition will occur somewhat closer to the conditions of the stream with the higher flow. A cocurrent heat exchanger is an example of a cocurrent flow exchange mechanism, two tubes have a liquid flowing in the same direction. One starts off hot at 60 °C, the cold at 20 °C. A thermoconductive membrane or an open section allows heat transfer between the two flows, the hot fluid heats the cold one, and the cold fluid cools down the warm one. The result is thermal equilibrium, Both fluids end up at around the temperature,40 °C. A similar example is the cocurrent concentration exchange, the system consists of two tubes, one with brine, the other with freshwater, and a semi permeable membrane which allows only water to pass between the two, in an osmotic process
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Reverberatory furnace
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A reverberatory furnace is a metallurgical or process furnace that isolates the material being processed from contact with the fuel, but not from contact with combustion gases. The term reverberation is used here in a sense of rebounding or reflecting. Chemistry determines the relationship between the fuel and the material, among other variables. There are, however, a great many designs. The applications of these fall into two general categories, metallurgical melting furnaces, and lower temperature processing furnaces typically used for metallic ores. Historically these furnaces have used solid fuel, and bituminous coal has proven to be the best choice, the brightly visible flames give more radiant heat transfer than anthracite coal or charcoal. Contact with the products of combustion, which may add undesirable elements to the material, is used to advantage in some processes. Control of the balance can alter the exhaust gas chemistry toward either an oxidizing or a reducing mixture. For example, cast iron can be puddled in an atmosphere to convert it to the lower-carbon mild steel or bar iron. The Siemens-Martin oven in open hearth steelmaking is also a reverbetratory furnace, Reverberatory furnaces were formerly also used for melting brass, bronze, and pig iron for foundry work. They were also, for the first 75 years of the 20th century, the first reverberatory furnaces were perhaps in the medieval period, and were used for melting bronze for casting bells. They were first applied to smelting metals in the late 17th century, Sir Clement Clerke and his son Talbot built cupolas or reverberatory furnaces in the Avon Gorge below Bristol in about 1678. In 1687, while obstructed from smelting lead, they moved on to copper, in the following decades, reverberatory furnaces were widely adopted for smelting these metals and also tin. They had the advantage over older methods that the fuel was mineral coal, in the 1690s, they applied the reverberatory furnace to melting pig iron for foundry purposes. The puddling furnace, introduced by Henry Cort in the 1780s to replace the older finery process, was also a variety of reverberatory furnace, today, reverberatory furnaces are widely used to melt secondary aluminium scrap for eventual use by die-casting industries. The simplest reverberatory is nothing more than a box lined with alumina refractory brick with a flue at one end. Conventional oil or gas burners are placed usually on side of the furnace to heat the brick. P. W. King, Sir Clement Clerke and the Adoption of coal in metallurgy, Transactions of the Newcomen Society 73, media related to Reverberatory furnaces at Wikimedia Commons
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Bloomery
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A bloomery is a type of furnace once widely used for smelting iron from its oxides. The bloomery was the earliest form of capable of smelting iron. A bloomerys product is a mass of iron and slag called a bloom. This mix of slag and iron in the bloom is termed sponge iron, the bloomery has now largely been superseded by the blast furnace, which produces pig iron. A bloomery consists of a pit or chimney with heat-resistant walls made of earth, clay, near the bottom, one or more pipes enter through the side walls. These pipes, called tuyères, allow air to enter the furnace, either by natural draught, an opening at the bottom of the bloomery may be used to remove the bloom, or the bloomery can be tipped over and the bloom removed from the top. The first step taken before the bloomery can be used is the preparation of the charcoal, the charcoal is produced by heating wood to produce the nearly pure carbon fuel needed for the smelting process. The ore is broken into pieces and usually roasted in a fire to remove any moisture in the ore. Any large impurities in the ore can be crushed and removed, since slag from previous blooms may have a high iron content, it can also be broken up and recycled into the bloomery with the new ore. In operation, the bloomery is preheated by burning charcoal, and once hot, iron ore and additional charcoal are introduced through the top, as the desired product of a bloomery is iron which is easily forgeable, it requires a low carbon content. The temperature and ratio of charcoal to iron ore must be controlled to keep the iron from absorbing too much carbon. Cast iron occurs when the iron melts and absorbs 2% to 4% carbon, because the bloomery is self-fluxing the addition of limestone is not required to form a slag. The mixed iron and slag cool to form a spongy mass referred to as the bloom. Because the bloom is highly porous, and its spaces are full of slag. Iron treated this way is said to be wrought, and the resulting iron and it is also possible to produce blooms coated in steel by manipulating the charge of and air flow to the bloomery. The onset of the Iron Age in most parts of the world coincides with the first widespread use of the bloomery, while earlier examples of iron are found, their high nickel content indicates that this is meteoric iron. Other early samples of iron may have produced by accidental introduction of iron ore in bronze smelting operations. Iron appears to have been smelted in the West as early as 3000 BC, in the West, iron began to be used around 1200 BC
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Blowing house
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A blowing house or blowing mill was a building used for smelting tin in Cornwall and on Dartmoor in Devon, in South West England. The remains of over 40 blowing houses have been identified on Dartmoor, each of these smeltings was taxed separately until 1303 when they were replaced by a single tax on the finished product. It is likely that this tax change was due to the smelting process provided by the blowing houses. In Devon there are references to blowing mills throughout the 16th and 17th centuries. However, by 1730 there were only two blowing mills working in the whole of the county, at Sheepstor and Plympton, the smelting house at Eylesbarrow tin mine which was in operation during the first half of the 19th century had two furnaces, one of each type. On Dartmoor, blowing houses were rectangular buildings between around 16 to 32 feet in length and around half this in width, the molten metal ran out from the bottom of the furnace into a granite trough or float from where it was ladled into stone moulds. Archaeological investigation of blowing houses started in 1866 when John Kelly examined the lower mill at Yealm Steps, since then, research on the tin industry in the south west has continued, for instance The Dartmoor Tinworking Interest Group was formed in 1991. There is evidence for furnaces that match the description given by Pryce at Upper and Lower Merrivale, Avon Dam, each of these sites has two upright granite slabs about 2 to 3 feet apart set into the floor area of the mill, leaving space behind for the bellows. The Merrivale sites also have a slab at the back, making a basic hearth shape, the accompanying photograph shows the two side slabs of the furnace at the Lower Merrivale blowing house, with the somewhat displaced float stone between them. The mouldstone, filled with rainwater, is just above and to the right, the moulds vary in size and shape, the largest known from Dartmoor being that from Upper Merrivale at 280 by 390 millimetres, and the smallest 180 millimetres square at Longstone. The only properly documented find of a tin ingot from Dartmoor has a hole through it which matches the supposed practice of placing a stick in the mould when pouring in the molten tin. The stick would burn away leaving the hole which would be used to out the solid ingot from the mould and would later be useful to tie up the ingots for carriage. He speculated that it was the surplus that remained after the normal ingots had been cast. Cornish ingots were much larger, averaging around 345 pounds, one of the best preserved blowing houses on Dartmoor is above Merrivale Bridge on the River Walkham. It has a mould stone close to its entrance and the wheel-pit can be easily traced, some blowing houses also housed crushing or grinding mills, and at Gobbet Mine on the River Swincombe both the upper and lower grinding stones were found. Dartmoor tin-mining Blowing engine Bryan Earl Cornish mining, the techniques of metal mining in the West of England, past and present, 2nd edition, Cornish Hillside Publications,1994
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Tin
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Tin is a chemical element with symbol Sn and atomic number 50. It is a metal in group 14 of the periodic table. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide, Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, metallic tin is not easily oxidized in air. The first alloy used on a scale was bronze, made of tin and copper. After 600 BC, pure metallic tin was produced, pewter, which is an alloy of 85–90% tin with the remainder commonly consisting of copper, antimony, and lead, was used for flatware from the Bronze Age until the 20th century. In modern times, tin is used in alloys, most notably tin/lead soft solders. Another large application for tin is corrosion-resistant tin plating of steel, inorganic tin compounds are rather non-toxic. Because of its low toxicity, tin-plated metal was used for packaging as tin cans. However, overexposure to tin may cause problems with metabolizing essential trace elements such as copper and zinc, Tin is a soft, malleable, ductile and highly crystalline silvery-white metal. When a bar of tin is bent, a sound known as the tin cry can be heard from the twinning of the crystals. Tin melts at the low temperature of about 232 °C, the lowest in group 14, the melting point is further lowered to 177.3 °C for 11 nm particles. β-tin, which is stable at and above room temperature, is malleable, in contrast, α-tin, which is stable below 13.2 °C, is brittle. α-tin has a cubic crystal structure, similar to diamond. α-tin has no properties at all because its atoms form a covalent structure in which electrons cannot move freely. It is a dull-gray powdery material with no common uses other than a few specialized semiconductor applications and these two allotropes, α-tin and β-tin, are more commonly known as gray tin and white tin, respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C, in cold conditions, β-tin tends to transform spontaneously into α-tin, a phenomenon known as tin pest. Commercial grades of tin resist transformation because of the effect of the small amounts of bismuth, antimony, lead
23.
Iron ore
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Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are rich in iron oxides and vary in color from dark grey, bright yellow. The iron itself is found in the form of magnetite, hematite, goethite, limonite or siderite. Ores containing very high quantities of hematite or magnetite are known as ore or direct shipping ore. Iron ore is the raw material used to make pig iron, indeed, it has been argued that iron ore is more integral to the global economy than any other commodity, except perhaps oil. Metallic iron is virtually unknown on the surface of the Earth except as iron-nickel alloys from meteorites, although iron is the fourth most abundant element in the Earths crust, comprising about 5%, the vast majority is bound in silicate or more rarely carbonate minerals. Prior to the revolution, most iron was obtained from widely available goethite or bog ore, for example during the American Revolution. Prehistoric societies used laterite as a source of iron ore, historically, much of the iron ore utilized by industrialized societies has been mined from predominantly hematite deposits with grades of around 70% Fe. These deposits are referred to as direct shipping ores or natural ores. Iron-ore mining methods vary by the type of ore being mined, there are four main types of iron-ore deposits worked currently, depending on the mineralogy and geology of the ore deposits. These are magnetite, titanomagnetite, massive hematite and pisolitic ironstone deposits, banded iron formations are sedimentary rocks containing more than 15% iron composed predominantly of thinly bedded iron minerals and silica. Banded iron formations occur exclusively in Precambrian rocks, and are weakly to intensely metamorphosed. Banded iron formations may contain iron in carbonates or silicates, banded iron formations are known as taconite within North America. The mining involves moving tremendous amounts of ore and waste, the waste comes in two forms, non-ore bedrock in the mine, and unwanted minerals which are an intrinsic part of the ore rock itself. The mullock is mined and piled in dumps, and the gangue is separated during the beneficiation process and is removed as tailings. Taconite tailings are mostly the mineral quartz, which is chemically inert and this material is stored in large, regulated water settling ponds. The typical magnetite iron-ore concentrate has less than 0. 1% phosphorus, 3–7% silica, currently magnetite iron ore is mined in Minnesota and Michigan in the U. S. Direct-shipping iron-ore deposits are exploited on all continents except Antarctica, with the largest intensity in South America
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Steel
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Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steels base metal is iron, which is able to take on two forms, body centered cubic and face centered cubic, depending on its temperature. It is the interaction of those allotropes with the elements, primarily carbon. In the body-centred cubic arrangement, there is an atom in the centre of each cube. Carbon, other elements, and inclusions within iron act as hardening agents that prevent the movement of dislocations that otherwise occur in the lattices of iron atoms. The carbon in steel alloys may contribute up to 2. 1% of its weight. Steels strength compared to pure iron is possible at the expense of irons ductility. With the invention of the Bessemer process in the mid-19th century and this was followed by Siemens-Martin process and then Gilchrist-Thomas process that refined the quality of steel. With their introductions, mild steel replaced wrought iron, further refinements in the process, such as basic oxygen steelmaking, largely replaced earlier methods by further lowering the cost of production and increasing the quality of the product. Today, steel is one of the most common materials in the world and it is a major component in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Modern steel is generally identified by various grades defined by assorted standards organizations, the noun steel originates from the Proto-Germanic adjective stakhlijan, which is related to stakhla. The carbon content of steel is between 0. 002% and 2. 1% by weight for plain iron–carbon alloys and these values vary depending on alloying elements such as manganese, chromium, nickel, iron, tungsten, carbon and so on. Basically, steel is an alloy that does not undergo eutectic reaction. In contrast, cast iron does undergo eutectic reaction, too little carbon content leaves iron quite soft, ductile, and weak. Carbon contents higher than those of steel make an alloy, commonly called pig iron, while iron alloyed with carbon is called carbon steel, alloy steel is steel to which other alloying elements have been intentionally added to modify the characteristics of steel. Common alloying elements include, manganese, nickel, chromium, molybdenum, boron, titanium, vanadium, tungsten, cobalt, and niobium. Additional elements are important in steel, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen, and copper. Alloys with a higher than 2. 1% carbon content, depending on other element content, cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties
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Sinter plant
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Sinter plants agglomerate iron ore fines with other fine materials at high temperature, to create a product that can be used in a blast furnace. The final product, a sinter, is a small, irregular nodule of iron mixed with small amounts of other minerals, the process, called sintering, causes the constituent materials to fuse to make a single porous mass with little change in the chemical properties of the ingredients. The purpose of sinter are to be used converting iron into steel, sinter plants, in combination with blast furnaces, are also used in non-ferrous smelting. About 70% of the primary lead production is still produced using the sinter plant–blast furnace combination. Many countries, including India, France and Germany, have underground deposits of ore in dust form. Such iron ore cannot be charged in a blast furnace. In the early 20th century, sinter technology was developed for converting ore fines into lumpy material chargeable in blast furnaces, sinter technology took 30 years to gain acceptance in the iron-making domain, but now plays an important role. Initially developed to generate steel, it is now a means of using metallurgical waste generated in steel plants to enhance blast furnace operation, the largest sinter plant is located in Chennai, India, and employs 10,000 people. Main feed into a plant is base mix, which consists of iron ore fines, coke fines. In addition to base mix, coke fines, flux fines, sinter fines, iron dust and plant waste are mixed in proportion in a rotary drum, often called mixing and nodulizing drum. Calcined lime is used as binder of the material along with water to form feed-sinter of about 5 to 7 mm in size. This sinter globules are fed to sintering machine and burnt there-in to produce blast furnace feed sinter, material is put on a sinter machine in two layers. The bottom layer may vary in thickness from 30 to 75 millimetres, a 12 to 20 mm sinter fraction is used, also referred to as the hearth layer. The second, covering layer consists of mixed materials, making for a total bed height of 350 to 660 millimetres, the mixed materials are applied with drum feeders and roll feeders, which distributes the nodules in certain depth throughout the sinterring machine. The upper layer is smoothed using a leveler, the material, also known as a charge, enters the ignition furnace into rows of multi-slit burners. In the case of one plant, the first zone has eleven burners, the next zone typically offers 12 burners. Air is sucked from the bottom of the bed of mixed material throughout the sintering machine, fire penetrates the mixed material gradually, until it reaches the hearth layer. This end point of burning is called burn through point, the hearth layer, which is nothing but sinter in smaller size, restricts sticking of hot sinter with pallets
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Ferrous metallurgy
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Ferrous metallurgy involves processes and alloys based on iron. It began far back in prehistory, the earliest surviving iron artifacts, from the 4th millennium BC in Egypt, were made from meteoritic iron-nickel. It is not known when or where the smelting of iron ores began. The use of iron was known by the 1st millennium BC. During the medieval period, means were found in Europe of producing iron from cast iron using finery forges. For all these processes, charcoal was required as fuel, Steel was first produced in antiquity as an alloy. Its process of production, Wootz steel, was exported before the 4th century BC to ancient China, Africa, archaeological evidence of cast iron appears in 5th century BC China. New methods of producing it by carburizing bars of iron in the process were devised in the 17th century. During the Industrial Revolution, new methods of producing bar iron without charcoal were devised, in the late 1850s, Henry Bessemer invented a new steelmaking process, that involved blowing air through molten pig iron to burn off carbon, and so to produce mild steel. This and other 19th-century and later processes have displaced the use of wrought iron, today, wrought iron is no longer produced on a commercial scale. Iron was extracted from iron–nickel alloys, which comprise about 6% of all meteorites that fall on the Earth and that source can often be identified with certainty because of the unique crystalline features of that material, which are preserved when the metal is worked cold or at low temperature. Those artifacts include, for example, a bead from the 5th millennium BC found in Iran and spear tips and ornaments from Ancient Egypt, meteoric iron has been identified also in a Chinese axe head from the middle of the 2nd millennium BC. These early uses appear to have been ceremonial or ornamental. Meteoritic iron is very rare, and the metal was very expensive. The early Hittites are known to have bartered iron for silver, at a rate of 40 times the irons weight, typically pea-size bits of metal were cold-hammered into disks and fitted to a bone handle. These artifacts were used as trade goods with other Arctic peoples. When the American polar explorer Robert Peary shipped the largest piece of the meteorite to the American Museum of Natural History in New York City in 1897, another example of a late use of meteoritic iron is an adze from around 1000 AD found in Sweden. Media related to Objects made from meteoritic iron at Wikimedia Commons Native iron in the state occurs rarely as small inclusions in certain basalt rocks
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High Middle Ages
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The High Middle Ages or High Medieval Period was the period of European history around the 11th, 12th, and 13th centuries. The High Middle Ages were preceded by the Early Middle Ages and followed by the Late Middle Ages, by 1250 the robust population increase greatly benefited the European economy, reaching levels that would not be seen again in some areas until the 19th century. This trend was checked in the Late Middle Ages by a series of calamities, notably the Black Death but also including numerous wars, from about the year 780 onwards, Europe saw the last of the barbarian invasions and became more socially and politically organized. The Carolingian Renaissance led to scientific and philosophical revival of Europe, the first universities were established in Bologna, Paris, Oxford and Modena. The Vikings had settled in the British Isles, France and elsewhere, the Magyars had ceased their expansion in the 10th century, and by the year 1000, a Christian Kingdom of Hungary was recognized in Central Europe, forming alliances with regional powers. With the brief exception of the Mongol invasions in the 13th century, in the 11th century, populations north of the Alps began to settle new lands, some of which had reverted to wilderness after the end of the Roman Empire. In what is known as the clearances, vast forests. At the same time settlements moved beyond the boundaries of the Frankish Empire to new frontiers in Europe, beyond the Elbe River. The High Middle Ages produced many different forms of intellectual, spiritual, the rediscovery of the works of Aristotle led Thomas Aquinas and other thinkers of the period to develop Scholasticism, a combination of Catholicism and ancient philosophy. For much of the time period Constantinople remained Europes most populous city, in architecture, many of the most notable Gothic cathedrals were built or completed during this era. The Crisis of the Late Middle Ages, beginning at the start of the 14th century, in England, the Norman Conquest of 1066 resulted in a kingdom ruled by a Francophone nobility. The Normans invaded Ireland by force in 1169 and soon established throughout most of the country. Likewise, Scotland and Wales were subdued to vassalage at about the same time, the Exchequer was founded in the 12th century under King Henry I, and the first parliaments were convened. In 1215, after the loss of Normandy, King John signed the Magna Carta into law, from the mid-tenth to the mid-11th centuries, the Scandinavian kingdoms were unified and Christianized, resulting in an end of Viking raids, and greater involvement in European politics. King Cnut of Denmark ruled over both England and Norway, after Cnuts death in 1035, England and Norway were lost, and with the defeat of Valdemar II in 1227, Danish predominance in the region came to an end. Meanwhile, Norway extended its Atlantic possessions, ranging from Greenland to the Isle of Man, while Sweden, under Birger Jarl, however, the Norwegian influence started to decline already in the same period, marked by the Treaty of Perth of 1266. Also, civil wars raged in Norway between 1130 and 1240, by the time of the High Middle Ages, the Carolingian Empire had been divided and replaced by separate successor kingdoms called France and Germany, although not with their modern boundaries. Germany was under the banner of the Holy Roman Empire, which reached its mark of unity
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Namur (province)
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Namur is a province of Wallonia, one of the three regions of Belgium. It borders on the Walloon provinces of Hainaut, Walloon Brabant, Liège and Luxembourg in Belgium and its capital is the city of Namur. It has an area of 3,664 square kilometres and is divided into three administrative districts containing a total of 38 municipalities, list of rulers of Namur Province de Namurs official website Namur, one of the nine provinces of Belgium
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Wallonia
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Wallonia is a region of Belgium. Wallonia is primarily French-speaking, and accounts for 55% of the territory of Belgium, unlike Flanders, the Walloon Region was not merged with the French Community of Belgium which is the political entity that is responsible for matters related mainly to culture and education. The German-speaking minority in the east forms the German-speaking Community of Belgium, during the industrial revolution, Wallonia was second only to the United Kingdom in industrialization, capitalizing on its extensive deposits of coal and iron. This brought the wealth, and, from the beginning of the 19th to the middle of the 20th century. Since World War II the importance of industry has greatly diminished. Wallonia now suffers high unemployment and has a significantly lower GDP per capita than Flanders. The economic inequalities and linguistic divide between the two are major sources of conflict in Belgium and is a major factor in Flemish separatism. The capital of Wallonia is Namur but the city with the greatest population is Charleroi, most of Wallonias major cities and two-thirds of its population lie along the Sambre and Meuse valley, the former industrial backbone of Belgium. To the north lies the Central Belgian Plateau, which, like Flanders, is relatively flat, in the south-east lie the Ardennes, hilly and sparsely populated. Wallonia borders Flanders and the Netherlands in the north, France to the south and west, Wallonia has been a member of the Organisation Internationale de la Francophonie since 1980. The term Wallonia can mean different things in different contexts. One of the three regions of Belgium is still constitutionally defined as the Walloon Region, but the regions government has renamed it Wallonia. In practice, the difference between the two terms is small and what is meant is usually clear, based on context, the root of the word Wallonia, like the words Wales, Cornwall and Wallachia, is the Germanic word Walha, meaning the strangers. Wallonia is named after the Walloons, the population of the Burgundian Netherlands speaking Romance languages, in Middle Dutch, the term Walloons also included the French-speaking population of the Prince-Bishopric of Liège or the whole population of the Romanic sprachraum within the medieval Low Countries. Julius Caesar conquered Gaul in 57 BC, the Low Countries became part of the larger Gallia Belgica province which originally stretched from southwestern Germany to Normandy and the southern part of the Netherlands. The population of territory was Celtic with a Germanic influence which was stronger in the north than in the south of the province. The ancestors of the Walloons became Gallo-Romans and were called the Walha by their Germanic neighbours, the Walha abandoned their Celtic dialects and started to speak Vulgar Latin. The Merovingian Franks gradually gained control of the region during the 5th century, the language border began to crystallize between 700 under the reign of the Merovingians and Carolingians and around 1000 after the Ottonian Renaissance
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Belgium
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Belgium, officially the Kingdom of Belgium, is a sovereign state in Western Europe bordered by France, the Netherlands, Germany, Luxembourg, and the North Sea. It is a small, densely populated country which covers an area of 30,528 square kilometres and has a population of about 11 million people. Additionally, there is a group of German-speakers who live in the East Cantons located around the High Fens area. Historically, Belgium, the Netherlands and Luxembourg were known as the Low Countries, the region was called Belgica in Latin, after the Roman province of Gallia Belgica. From the end of the Middle Ages until the 17th century, today, Belgium is a federal constitutional monarchy with a parliamentary system of governance. It is divided into three regions and three communities, that exist next to each other and its two largest regions are the Dutch-speaking region of Flanders in the north and the French-speaking southern region of Wallonia. The Brussels-Capital Region is a bilingual enclave within the Flemish Region. A German-speaking Community exists in eastern Wallonia, Belgiums linguistic diversity and related political conflicts are reflected in its political history and complex system of governance, made up of six different governments. Upon its independence, declared in 1830, Belgium participated in the Industrial Revolution and, during the course of the 20th century, possessed a number of colonies in Africa. This continuing antagonism has led to several far-reaching reforms, resulting in a transition from a unitary to a federal arrangement during the period from 1970 to 1993. Belgium is also a member of the Eurozone, NATO, OECD and WTO. Its capital, Brussels, hosts several of the EUs official seats as well as the headquarters of major international organizations such as NATO. Belgium is also a part of the Schengen Area, Belgium is a developed country, with an advanced high-income economy and is categorized as very high in the Human Development Index. A gradual immigration by Germanic Frankish tribes during the 5th century brought the area under the rule of the Merovingian kings, a gradual shift of power during the 8th century led the kingdom of the Franks to evolve into the Carolingian Empire. Many of these fiefdoms were united in the Burgundian Netherlands of the 14th and 15th centuries, the Eighty Years War divided the Low Countries into the northern United Provinces and the Southern Netherlands. The latter were ruled successively by the Spanish and the Austrian Habsburgs and this was the theatre of most Franco-Spanish and Franco-Austrian wars during the 17th and 18th centuries. The reunification of the Low Countries as the United Kingdom of the Netherlands occurred at the dissolution of the First French Empire in 1815, although the franchise was initially restricted, universal suffrage for men was introduced after the general strike of 1893 and for women in 1949. The main political parties of the 19th century were the Catholic Party, French was originally the single official language adopted by the nobility and the bourgeoisie
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Charcoal
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Charcoal is a lightweight, black residue, consisting of carbon and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis- the heating of wood or other substances in the absence of oxygen, the whole pile is covered with turf or moistened clay. The firing is begun at the bottom of the flue, the success of the operation depends upon the rate of the combustion. The operation is so delicate that it was left to colliers. They often lived alone in small huts in order to tend their wood piles, for example, in the Harz Mountains of Germany, charcoal burners lived in conical huts called Köten which are still much in evidence today. The massive production of charcoal was a cause of deforestation. The increasing scarcity of easily harvested wood was a factor behind the switch to fossil fuel equivalents, mainly coal. Charcoal made at 300 °C is brown, soft and friable, and readily inflames at 380 °C, made at higher temperatures it is hard and brittle, in Finland and Scandinavia, the charcoal was considered the by-product of wood tar production. The best tar came from pine, thus pinewoods were cut down for tar pyrolysis, the residual charcoal was widely used as substitute for metallurgical coke in blast furnaces for smelting. Tar production led to deforestation, it has been estimated all Finnish forests are younger than 300 years. The end of tar production at the end of the 19th century resulted in rapid re-forestation, the charcoal briquette was first invented and patented by Ellsworth B. A. Zwoyer of Pennsylvania in 1897 and was produced by the Zwoyer Fuel Company. The process was popularized by Henry Ford, who used wood. Ford Charcoal went on to become the Kingsford Company, Charcoal has been made by various methods. The traditional method in Britain used a clamp and this is essentially a pile of wooden logs leaning against a chimney. The chimney consists of 4 wooden stakes held up by some rope, the logs are completely covered with soil and straw allowing no air to enter. It must be lit by introducing some burning fuel into the chimney, if the soil covering gets torn by the fire, additional soil is placed on the cracks. Once the burn is complete, the chimney is plugged to prevent air from entering, the true art of this production method is in managing the sufficient generation of heat, and its transfer to wood parts in the process of being carbonised. A strong disadvantage of this method is the huge amount of emissions that are harmful to human health
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Abraham Darby I
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Abraham Darby, in his later life called Abraham Darby the Elder, now sometimes known for convenience as Abraham Darby I was the first and best known of several men of that name. Born into an English Quaker family that played an important role in the Industrial Revolution and this was a major step forward in the production of iron as a raw material for the Industrial Revolution. Abraham Darby was the son of John Darby, a farmer and locksmith by trade. He was born at Woodsettle, Woodsetton, Staffordshire, just across the county boundary from Dudley and he was descended from nobility, his great-grandmother Jane was an illegitimate child of Edward Sutton, 5th Baron Dudley. Abrahams great-grandmother was a sister of the blood to Dud Dudley. Unfortunately, the iron that Dudley produced was not acceptable to the charcoal ironmasters, however, this may have inspired his great-grandnephew Darby to perfect this novel method of smelting. During the early 1690s Darby was apprenticed in Birmingham to Jonathan Freeth, a fellow Quaker, the combination of these two insights was to lead to Darbys development of the coke-fuelled blast furnace in 1709. Freeth encouraged Darby to become an active member in the Society of Friends. In 1699, when he completed his apprenticeship, he married Mary Sergeant and moved to Bristol, there was a small community of Quakers in Bristol, and Darby soon gained a reputation for skill and enterprise. In 1702 Darby joined with a number of fellow Quakers to form the Bristol Brass Company and he brought in Dutchmen to operate a brass battery work, making cooking pots and other holloware under a trip hammer. He also developed a method for casting pots in greensand moulds and this enabled pots to be mass-produced and to be thinner than those made by the traditional process of casting in loam moulds. For this purpose, he established the Cheese Lane Foundry in 1704, initially he cast brass pots, but by 1705, he moved on to using iron. A young Welsh apprentice, John Thomas, solved the problem by using sand for the mould, with a special casting box, using this casting method Darby could cast pots of sufficient thinness and lightness. Darby took out a patent on the new casting method in 1707, Darbys successors sold pots over wide areas of England and Wales, and had a virtual monopoly in the trade. For this he used an air furnace of a kind developed by Sir Clement Clerke, initially for smelting lead near Bristol. In 1700, another group of Bristol Quakers had agreed to set up a brass works somewhere in England and it is not clear where, but by 1712, Caleb Lloyd, Jeffrey Pinnell, Abraham Darby and his brother-in-law Thomas Harvey had brass works at Coalbrookdale. However, Darby was not a partner in establishing Tern Mill, near Tern Hall in 1709, though his partners Thomas Harvey, Lloyd, at this point Darby decided to leave the brass company and concentrate on his iron founding pursuits. Darby leased the furnace in September 1708, and set to work preparing to get it into blast and his first account book, running from 20 October 1708 to 4 January 1710 survives
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Hot blast
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Hot blast refers to the preheating of air blown into a blast furnace or other metallurgical process. As this considerably reduced the fuel consumed, hot blast was one of the most important technologies developed during the Industrial Revolution, hot blast also allowed higher furnace temperatures, which increased the capacity of furnaces. As first developed, it worked by alternately storing heat from the flue gas in a firebrick-lined vessel with multiple chambers. This is known as regenerative heating, hot blast was invented and patented for iron furnaces by James Beaumont Neilson in 1828 at Wilsontown Ironworks in Scotland, but was later applied in other contexts, including late bloomeries. Later the carbon monoxide in the gas was burned to provide additional heat. James Beaumont Neilson, previously foreman at Glasgow gas works, invented the system of preheating the blast for a furnace and he, with partners including Charles Macintosh, patented this in 1828. Initially the heating vessel was made of iron plates, but these oxidized. On the basis of a January 1828 patent, Thomas Botfield has a claim as the inventor of the hot blast method. Neilson is credited as inventor of hot blast because he won patent litigation, Neilson and his partners engaged in substantial litigation to enforce the patent against infringers. The spread of technology across Britain was relatively slow. By 1840,58 ironmasters had taken out licenses, yielding a royalty income of £30,000 per year, by the time the patent expired there were 80 licenses. In 1843, just after it expired,42 of the 80 furnaces in south Staffordshire were using hot blast, other advantages of hot blast were that raw coal could be used instead of coke. In Scotland, the poor black band ironstone could be profitably smelted. It also increased the output of furnaces. In the case of Calder ironworks from 5.6 tons per day in 1828 to 8.2 in 1833, early hot blast stoves were troublesome, as thermal expansion and contraction could cause breakage of pipes. This was somewhat remedied by supporting the pipes on rollers and it was also necessary to devise new methods of connecting the blast pipes to the tuyeres, as leather could not longer be used. Ultimately this principle was applied even more efficiently in regenerative heat exchangers, such as the Cowper stove, independently, George Crane and David Thomas, of the Yniscedwyn Works in Wales, conceived of the same idea, and Crane filed for a British patent in 1836. They began producing iron by the new process on February 5,1837, Crane subsequently bought Gessenhainers patent and patented additions to it, controlling the use of the process in both Britain and the US
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James Beaumont Neilson
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James Beaumont Neilson was a Scottish inventor whose hot-blast process greatly increased the efficiency of smelting iron. He was the son of the engineer Walter Neilson, a millwright and later engine wright and he was born in Shettleston and was trained as an engine wright. After the failure of a colliery at Irvine he was appointed foreman of the Glasgow Gasworks in 1817 at the age of only 25, five years later he became the manager and engineer there, a position he would hold for 40 years. Experiments were continued at Clyde Iron Works, leading to his forming a partnership with Charles Macintosh, patents were obtained for the system in 1828. Experimentation showed that a temperature of 600° Fahrenheit reduced consumption to a third of that with cold blast and it also enabled the exploitation of black band ironstone, the use of which had previously proved unprofitable. In the early 1830s litigation was successfully conducted against those who adopted his methods without licence, after that, Neilson and his partners licensed it widely at one shilling per ton iron made, a level low enough to discourage evasion. The royalties were initially low, but by 1840 were producing £30,000 per year from 58 ironmaste, between 1839 and the expiry of the patent in 1842 a considerable number of proceedings were brought. Neilson v Baird was heard in the Court of Session in 1843, in a trial lasting 10 days, further proceedings against Baird ended in the award of damages of £160,000. Neilson retired from Glasgow Gasworks in 1847 and he bought an estate on Bute. Later he bought an estate at Queenshill, near Kirkcudbright and his son, Walter Montgomerie Neilson, erected a monument to his memory there in 1883. Both in Glasgow and near Kirkcubright, he founded institutions for the education of working men, william Neilson, Jamess brother, founded the Glasgow engineers and locomotive manufacturers Neilson and Company, in 1836, partly financed by James. Jamess son Walter took over the running of the firm in 1843, Neilson v Harford James Beaumont Neilson from Memoirs and portraits of one hundred Glasgow men
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Water wheel
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A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle, vertical wheels can transmit power either through the axle or via a ring gear and typically drive belts or gears, horizontal wheels usually directly drive their load. Water wheels were still in use well into the 20th century. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a wheel is called a mill race. The race bringing water from the pond to the water wheel is a headrace. In the mid to late 18th century John Smeatons scientific investigation of the water led to significant increases in efficiency supplying much needed power for the Industrial Revolution. Water wheels began being displaced by the smaller, less expensive and more efficient turbine, developed by Benoît Fourneyron, turbines are capable of handling high heads, or elevations, that exceed the capability of practical-sized waterwheels. The main difficulty of water wheels is their dependence on flowing water, modern hydroelectric dams can be viewed as the descendants of the water wheel, as they too take advantage of the movement of water downhill. The two main functions of water wheels were historically water-lifting for irrigation purposes and as a power source, when used for water-lifting power can be supplied by either human or animal force or by the water current itself. Water wheels come in two designs, either a vertical or a horizontal axle. The latter type can be subdivided, depending on where the hits the wheel. Engineers of the Hellenistic era Mediterranean region are credited with the development of the water wheel, Mediterranean engineers of the Hellenistic and Roman periods were also the first to use it for both irrigation and as a power source. The technological breakthrough occurred in the advanced and scientifically minded Hellenistic period between the 3rd and 1st centuries BCE. This is seen as an evolution of the paddle-driven water-lifting wheels that had appeared in ancient Egypt by the 4th century BCE. According to John Peter Oleson, both the wheel and the hydraulic Noria appeared in Egypt by the 4th century BCE. This is supported by finds at Faiyum, where the oldest archeological evidence of a water-wheel has been found
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Wang Zhen (inventor)
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This article is about Wang Zhen, agronomist and inventor. For other historical figures with this name, see Wang Zhen, Wang Zhen was an official of the Yuan Dynasty of China. He was one of the innovators of the wooden movable type printing technology. His illustrated agricultural treatise was also one of the most advanced of its day, covering a range of equipment and technologies available in the late 13th. Wang Zhen was born in Shandong province, and spent many years as an official of both Anhui and Jiangxi provinces. From the years 1290 to 1301, he was a magistrate for Jingde, Anhui province, the wooden movable type was described in Wang Zhens publication of 1313 AD, known as the Nong Shu, or Book of Agriculture. Although the title describes the focus of the work, it incorporated much more information on a wide variety of subjects that was not limited to the scope of agriculture. Wang Zhens Nong Shu of 1313 was an important medieval treatise outlining the application and use of the various Chinese sciences, technologies. From water powered bellows to movable type printing, it is considered a masterpiece on contemporary medieval Chinese technology. Hence, a such as the Nong Shu could help rural farmers maximize efficiency of producing yields. The Nong Shu was a long book even for its own time. The Chinese during the Han Dynasty were the first to apply hydraulic power in working the bellows of the blast furnace in creating cast iron. This was recorded in the year 31 AD, an innovation of the engineer Du Shi, after Du Shi, Chinese in subsequent dynastic periods continued the use of water power to operate the bellows of the blast furnace. The 5th century text Shui Jing Zhu mentions the use of rushing water to power waterwheels, as does the Tang Dynasty geography text of the Yuan-he Jun Xian Tu Chi. Although Du Shi was the first to apply power to bellows in metallurgy. Wang Zhen is best known for his usage of wooden movable type while he was a magistrate of Jingde in Anhui province from 1290 to 1301. His main contribution was improving the speed of typesetting with simple devices, along with the complex. Wang Zhen improved the earlier experimented process by adding the methods of specific type cutting and finishing, making the type case and revolving table that made the process more efficient
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Yuan dynasty
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The Yuan dynasty, officially the Great Yuan, was the empire or ruling dynasty of China established by Kublai Khan, leader of the Mongolian Borjigin clan. His realm was, by point, isolated from the other khanates and controlled most of present-day China and its surrounding areas. Some of the Mongolian Emperors of the Yuan mastered the Chinese language, while others used their native language. The Yuan dynasty is considered both a successor to the Mongol Empire and an imperial Chinese dynasty and it was the khanate ruled by the successors of Möngke Khan after the division of the Mongol Empire. In official Chinese histories, the Yuan dynasty bore the Mandate of Heaven, following the Song dynasty, the dynasty was established by Kublai Khan, yet he placed his grandfather Genghis Khan on the imperial records as the official founder of the dynasty as Taizu. In addition to Emperor of China, Kublai Khan also claimed the title of Great Khan, supreme over the other khanates, the Chagatai, the Golden Horde. As such, the Yuan was also referred to as the Empire of the Great Khan. However, while the claim of supremacy by the Yuan emperors was at times recognized by the khans, their subservience was nominal. In 1271, Kublai Khan imposed the name Great Yuan, establishing the Yuan dynasty, dà Yuán is from the clause 大哉乾元 in the Commentaries on the Classic of Changes section regarding Qián. The counterpart in Mongolian language was Dai Ön Ulus, also rendered as Ikh Yuan Üls or Yekhe Yuan Ulus, in Mongolian, Dai Ön is often used in conjunction with the Yeke Mongghul Ulus, resulting in Dai Ön Yeke Mongghul Ulus, meaning Great Mongol State. Nevertheless, both terms can refer to the khanate within the Mongol Empire directly ruled by Great Khans before the actual establishment of the Yuan dynasty by Kublai Khan in 1271. Genghis Khan united the Mongol and Turkic tribes of the steppes and he and his successors expanded the Mongol empire across Asia. Under the reign of Genghis third son, Ögedei Khan, the Mongols destroyed the weakened Jin dynasty in 1234, Ögedei offered his nephew Kublai a position in Xingzhou, Hebei. Kublai was unable to read Chinese but had several Han Chinese teachers attached to him since his early years by his mother Sorghaghtani and he sought the counsel of Chinese Buddhist and Confucian advisers. Möngke Khan succeeded Ögedeis son, Güyük, as Great Khan in 1251 and he granted his brother Kublai control over Mongol held territories in China. Kublai built schools for Confucian scholars, issued paper money, revived Chinese rituals and he adopted as his capital city Kaiping in Inner Mongolia, later renamed Shangdu. Many Han Chinese and Khitan defected to the Mongols to fight against the Jin, two Han Chinese leaders, Shi Tianze, Liu Heima, and the Khitan Xiao Zhala defected and commanded the 3 Tumens in the Mongol army. Liu Heima and Shi Tianze served Ogödei Khan, Liu Heima and Shi Tianxiang led armies against Western Xia for the Mongols
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Han dynasty
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The Han dynasty was the second imperial dynasty of China, preceded by the Qin dynasty and succeeded by the Three Kingdoms period. Spanning over four centuries, the Han period is considered an age in Chinese history. To this day, Chinas majority ethnic group refers to itself as the Han people and it was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han, and briefly interrupted by the Xin dynasty of the former regent Wang Mang. This interregnum separates the Han dynasty into two periods, the Western Han or Former Han and the Eastern Han or Later Han, the emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the gentry class. The Han Empire was divided into areas controlled by the central government using an innovation inherited from the Qin known as commanderies. These kingdoms gradually lost all vestiges of their independence, particularly following the Rebellion of the Seven States, from the reign of Emperor Wu onward, the Chinese court officially sponsored Confucianism in education and court politics, synthesized with the cosmology of later scholars such as Dong Zhongshu. This policy endured until the fall of the Qing dynasty in 1911 AD, the Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty. The coinage issued by the government mint in 119 BC remained the standard coinage of China until the Tang dynasty. The period saw a number of limited institutional innovations, the Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han launched several campaigns against them. The ultimate Han victory in these wars eventually forced the Xiongnu to accept vassal status as Han tributaries, the territories north of Hans borders were quickly overrun by the nomadic Xianbei confederation. Imperial authority was seriously challenged by large Daoist religious societies which instigated the Yellow Turban Rebellion. When Cao Pi, King of Wei, usurped the throne from Emperor Xian, following Liu Bangs victory in the Chu–Han Contention, the resulting Han dynasty was named after the Hanzhong fief. Chinas first imperial dynasty was the Qin dynasty, the Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the authority had collapsed in the face of rebellion. Although Xiang Yu proved to be a commander, Liu Bang defeated him at Battle of Gaixia. Liu Bang assumed the title emperor at the urging of his followers and is known posthumously as Emperor Gaozu, Changan was chosen as the new capital of the reunified empire under Han
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Cast iron
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Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its low melting temperature. Carbon ranging from 1. 8–4 wt%, and silicon 1–3 wt% are the main alloying elements of cast iron, Iron alloys with less carbon content are known as steel. While this technically makes the Fe–C–Si system ternary, the principle of cast iron solidification can be understood from the simpler binary iron–carbon phase diagram, cast iron tends to be brittle, except for malleable cast irons. It is resistant to destruction and weakening by oxidation, the earliest cast iron artefacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu in China. Cast iron was used in ancient China for warfare, agriculture, during the 15th century, cast iron became utilized for artillery in Burgundy, France, and in England during the Reformation. The first cast iron bridge was built during the 1770s by Abraham Darby III, cast iron is also used in the construction of buildings. Cast iron is made by re-melting pig iron, often along with quantities of iron, steel, limestone, carbon. Phosphorus and sulfur may be burnt out of the iron, but this also burns out the carbon. Depending on the application, carbon and silicon content are adjusted to the desired levels, other elements are then added to the melt before the final form is produced by casting. Cast iron is melted in a special type of blast furnace known as a cupola. After melting is complete, the molten cast iron is poured into a furnace or ladle. Cast irons properties are changed by adding various alloying elements, or alloyants, next to carbon, silicon is the most important alloyant because it forces carbon out of solution. A low percentage of silicon allows carbon to remain in solution forming iron carbide, a high percentage of silicon forces carbon out of solution forming graphite and the production of grey cast iron. Other alloying agents, manganese, chromium, molybdenum, titanium and vanadium counteracts silicon, promotes the retention of carbon, nickel and copper increase strength, and machinability, but do not change the amount of graphite formed. The carbon in the form of graphite results in an iron, reduces shrinkage, lowers strength. Sulfur, largely a contaminant when present, forms iron sulfide, the problem with sulfur is that it makes molten cast iron viscous, which causes defects. To counter the effects of sulfur, manganese is added because the two form into manganese sulfide instead of iron sulfide, the manganese sulfide is lighter than the melt so it tends to float out of the melt and into the slag
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Phosphorus
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Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but because it is reactive, phosphorus is never found as a free element on Earth. At 0. 099%, phosphorus is the most abundant pnictogen in the Earths crust, with few exceptions, minerals containing phosphorus are in the maximally oxidised state as inorganic phosphate rocks. The glow of phosphorus itself originates from oxidation of the white phosphorus — a process now termed chemiluminescence, together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a pnictogen. Phosphates are a component of DNA, RNA, ATP, and the phospholipids, demonstrating the link between phosphorus and life, elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphate mines contain fossils, especially marine fossils, because phosphate is present in the deposits of animal remains. Low phosphate levels are an important limit to growth in aquatic systems. The vast majority of compounds produced are consumed as fertilisers. Phosphate is needed to replace the phosphorus that plants remove from the soil, other applications include the role of organophosphorus compounds in detergents, pesticides, and nerve agents. Phosphorus exists as several forms that exhibit different properties. The two most common allotropes are white phosphorus and red phosphorus, from the perspective of applications and chemical literature, the most important form of elemental phosphorus is white phosphorus, often abbreviated as WP. It is a soft and waxy solid consists of tetrahedral P4 molecules. This P4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C when it starts decomposing to P2 molecules, White phosphorus exists in two crystalline forms, α and β. At room temperature, the α-form is stable, which is common and it has cubic crystal structure and at 195.2 K, it transforms into β-form. These forms differ in terms of the orientations of the constituent P4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile, the least dense, White phosphorus gradually changes to red phosphorus. This transformation is accelerated by light and heat, and samples of white phosphorus almost always some red phosphorus. For this reason, white phosphorus that is aged or otherwise impure is also called yellow phosphorus, when exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue
41.
Du Shi
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Du Shi was a Chinese governmental Prefect of Nanyang in 31 AD and a mechanical engineer of the Eastern Han Dynasty in ancient China. Du Shi is credited with being the first to apply power to operate bellows in metallurgy. His invention was used to operate piston-bellows of the blast furnace and then cupola furnace in order to forge cast iron and he worked as a censorial officer and administrator of several places during the reign of Emperor Guangwu of Han. He also led a military campaign in which he eliminated a small bandit army under Yang Yi. Although the year of his birth is uncertain, it is known that Du Shi was born in Henei, however, Du soon after swore his allegiance to Emperor Guangwu of Han, who is considered the true founder of the Eastern Han Dynasty. Under Emperor Guangwu, Du Shi was appointed as an officer in the Censorate and was in charge of monitoring affairs and upholding law, Du had Xiao summarily executed without explicit consent from the throne, sending in a report of the event only after the execution. Guangwu was not displeased with this, as he called him into court to grant him an insignia which justified his actions, shortly after this event, the bandit leader Yang Yi caused a major disturbance in Hedong Commandery, which Du Shi was sent to quell. When word of the arrival of Du Shis forces in the region, however, Du Shi anticipated this, sending a raiding party to burn the boats Yang Yi intended to use for his escape. After conscripting troops from Hedong Commandery, Du Shi led an ambush with a cavalry unit that dispersed Yangs bandits. For three years, Du served as a county magistrate in Henan province where his administration gained wide acclaim from provincial authorities, afterwards, Du distinguished himself as a Commandant in Pei and in Runan. In 31 he was appointed as an administrator over Nanyang, while serving there, he had an array of dykes and canals built for land reclamation and growth of local agriculture. It is here that he developed a water-powered reciprocator for bellows in smelting cast iron. It is recorded that the locals were so fond of him that they referred to him as Mother Du and compared him to noteworthy figures of history. Du Shi was by all means a local administrator, yet he made recommendations to the imperial court on policy issues. He recommended that the Tiger Tallies system be reinstated and this was a means for imperial authorities to check possible official corruption in the forgery of mobilization of troops for war. Du also nominated several minor officials he deemed worthy as candidates for higher posts in the capital, in a memorial of 37, he urged the court to consider Fu as the next Imperial Secretary. Du Shis reputation was somewhat stymied in 38 when he was accused of having one of his retainers sent to kill a man out of vengeance for his brother, in that same year, Du became ill and died. Despite Dus long-standing official career, the Director of Retainers Bao Yong reported that no funeral ceremony could be arranged for Du
42.
Piston
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A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder, in some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. An internal combustion engine is acted upon by the pressure of the combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the rod and onto the crankshaft. The connecting rod is attached to the piston by a swivelling gudgeon pin and this pin is mounted within the piston, unlike the steam engine, there is no piston rod or crosshead. The pin itself is of hardened steel and is fixed in the piston, a few designs use a fully floating design that is loose in both components. All pins must be prevented from moving sideways and the ends of the pin digging into the cylinder wall, gas sealing is achieved by the use of piston rings. These are a number of iron rings, fitted loosely into grooves in the piston. The rings are split at a point in the rim, allowing them to press against the cylinder with a light spring pressure. Two types of ring are used, the rings have solid faces and provide gas sealing, lower rings have narrow edges. There are many proprietary and detail design features associated with piston rings, pistons are cast from aluminium alloys. For better strength and fatigue life, some racing pistons may be forged instead, early pistons were of cast iron, but there were obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons that could survive engine combustion temperatures, it was necessary to develop new alloys such as Y alloy and Hiduminium, a few early gas engines had double-acting cylinders, but otherwise effectively all internal combustion engine pistons are single-acting. During World War II, the US submarine Pompano was fitted with a prototype of the infamously unreliable H. O. R, although compact, for use in a cramped submarine, this design of engine was not repeated. Media related to Internal combustion engine pistons at Wikimedia Commons Trunk pistons are long relative to their diameter and they act both as a piston and cylindrical crosshead. As the connecting rod is angled for much of its rotation, a longer piston helps to support this
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Bellows
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A bellows or pair of bellows is a device constructed to furnish a strong blast of air. It has many applications, in particular blowing on a fire to supply it with air, the term bellows is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight bag allowing the distance between the lens and film of a photographic camera to be varied is called a bellows. Bellows is only used in plural, the Old English name for bellows was blǽstbęlg, blást-bęlg blast-bag, blowing-bag, the prefix was dropped and by the eleventh century the simple bęlg, bylg, bylig was used. The word is cognate with belly, there are similar words in Old Norse, Swedish, and Danish, but the derivation is not certain. Bellows appears not to be cognate with the apparently similar Latin follis, several processes, such as metallurgical iron smelting and welding, require so much heat that they could only be developed after the invention, in antiquity, of the bellows. The bellows are used to deliver air to the fuel, raising the rate of combustion. Various kinds of bellows are used in metallurgy, Box bellows were and are used in Asia. Pot bellows were used in ancient Egypt, accordion bellows, with the characteristic pleated sides, have been used in Europe for many centuries. Piston bellows were developed in the middle of the 18th century in Europe, however, the double action piston bellows were utilised by the Han rulers in ancient China as early as the 3rd century BC. Metal bellows were made to absorb axial movement in a dynamic condition, often referred to as Axial Dynamics bellows types. The Han Dynasty Chinese mechanical engineer Du Shi is credited with being the first to apply power, through a waterwheel. His invention was used to operate piston bellows of blast furnaces in order to forge cast iron, the ancient Greeks, ancient Romans, and other civilizations used bellows in bloomery furnaces producing wrought iron. Bellows are also used to send pressurized air in a manner in a fired heater. In modern industry, reciprocating bellows are usually replaced with motorized blowers and these bellows blow a more constant, and thus stronger, blast than simple bellows. Such bellows existed in China at least since the 5th century BC, when it was invented, a piston is enclosed in a rectangular box with a handle coming out one side. The piston edges are covered with feathers, fur, or soft paper to ensure that it is airtight and lubricated. As the piston is pulled, air from one side enters and flows through the nozzle and as it is pushed air enters from the opposite side, the middle leave is fixed in place
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Wrought iron
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Wrought iron is an iron alloy with a very low carbon content in contrast to cast iron. It is a mass of iron with fibrous slag inclusions which gives it a grain resembling wood. Wrought iron is tough, malleable, ductile, corrosion-resistant and easily welded, before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. A wrought product is one that has been worked by forging, extruding, rolling, hammering, etcetera, to change its form. Wrought iron is a worked iron product that is seldom produced today as other cheaper. Historically, a modest amount of iron was refined into steel. The demand for wrought iron reached its peak in the 1860s with the adaptation of ironclad warships, however, as properties such as brittleness of mild steel improved, it became less costly and more widely available than wrought iron, whose usage then declined. Wrought iron is no longer produced on a commercial scale, many products described as wrought iron, such as guard rails, garden furniture and gates, are actually made of mild steel. They retain that description because they are made to resemble objects which in the past were wrought by hand by a blacksmith, the word wrought is an archaic past participle of the verb to work, and so wrought iron literally means worked iron. Wrought iron is a term for the commodity, but is also used more specifically for finished iron goods. It was used in that sense in British Customs records. Cast iron, unlike wrought iron, is brittle and cannot be worked either hot or cold, Cast iron can break if struck with a hammer. In the 17th, 18th, and 19th centuries, wrought iron went by a variety of terms according to its form, origin. While the bloomery process produced wrought iron directly from ore, cast iron or pig iron were the materials used in the finery forge. Pig iron and cast iron have higher content than wrought iron. Cast and especially pig iron have excess slag which must be at least partially removed to produce quality wrought iron, at foundries it was common to blend scrap wrought iron with cast iron to improve the physical properties of castings. Fusion eventually became accepted as relatively more important than composition below a given low carbon concentration. Another difference is that steel can be hardened by heat treating, historically, wrought iron was known as commercially pure iron, however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%
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Song Yingxing
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Song Yingxing, born in Yichun of Jiangxi, was a Chinese scientist and encyclopedist who lived during the late Ming Dynasty. He was the author of an encyclopedia that covered a variety of technical subjects. Comparing him to the famous French encyclopedist Denis Diderot, the British sinologist, Song Yingxing achieved only modest wealth and influence during his life. Born in 1587 to a family of reduced circumstances, he participated in the imperial examinations. However, he was unsuccessful in the metropolitan examination. Song sat for the test five times, the last being in 1631 at the age of 44, after this last failure, he held a series of minor positions in provincial government. The works for which Song is known today all date from 1636 to 1637, the repeated trips to the capital to participate in the metropolitan examination likely provided him with the broad base of knowledge demonstrated in the works. Song retired from life in 1644, after the fall of the Ming dynasty. Although Song Yingxings encyclopedia was a significant publication for his age, for example, the Four Great Books of Song compiled much earlier in the 10th and 11th centuries. Just a few decades before Yingxings work, there was also the Ming Dynasty encyclopedia of the Sancai Tuhui, written in 1607 and published in 1609. Song Yingxings famous work was the Tiangong Kaiwu, or The Exploitation of the Works of Nature, the Tiangong Kaiwu is an encyclopedia covering a wide range of technical issues, including the use of various gunpowder weapons. Copies of the book were very scarce in China during the Qing dynasty, at the same time, the Tiangong Kaiwu broke from Chinese tradition by rarely referencing previous written work. It is instead written in a style suggestive of first-hand experience. In the preface to the work, Song attributed this deviation from tradition to his poverty, Song Yingxing also published two scientific tractates that outline his cosmological views. In these, he discusses the concepts of qi and xing, qi has been described in many different ways by Chinese philosophers. To Song, it is a type of all-permeating vapor from which objects are formed. These solid objects eventually return to the state of qi, which eventually returns to the great void. Some objects, such as the sun and the moon, remain in qi form indefinitely, some objects, like water and fire, are intermediary between the two forms
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Bronze Age
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The Bronze Age is a historical period characterized by the use of bronze, proto-writing, and other early features of urban civilization. The Bronze Age is the principal period of the three-age Stone-Bronze-Iron system, as proposed in modern times by Christian Jürgensen Thomsen. An ancient civilization is defined to be in the Bronze Age either by smelting its own copper and alloying with tin, arsenic, or other metals, or by trading for bronze from production areas elsewhere. Copper-tin ores are rare, as reflected in the fact there were no tin bronzes in Western Asia before trading in bronze began in the third millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition, although the Iron Age generally followed the Bronze Age, in some areas, the Iron Age intruded directly on the Neolithic. Bronze Age cultures differed in their development of the first writing, according to archaeological evidence, cultures in Mesopotamia and Egypt developed the earliest viable writing systems. The overall period is characterized by use of bronze, though the place and time of the introduction. Human-made tin bronze technology requires set production techniques, tin must be mined and smelted separately, then added to molten copper to make bronze alloy. The Bronze Age was a time of use of metals. The dating of the foil has been disputed, the Bronze Age in the ancient Near East began with the rise of Sumer in the 4th millennium BC. Societies in the region laid the foundations for astronomy and mathematics, the usual tripartite division into an Early, Middle and Late Bronze Age is not used. Instead, a division based on art-historical and historical characteristics is more common. The cities of the Ancient Near East housed several tens of thousands of people, ur in the Middle Bronze Age and Babylon in the Late Bronze Age similarly had large populations. The earliest mention of Babylonia appears on a tablet from the reign of Sargon of Akkad in the 23rd century BC, the Amorite dynasty established the city-state of Babylon in the 19th century BC. Over 100 years later, it took over the other city-states. Babylonia adopted the written Semitic Akkadian language for official use, by that time, the Sumerian language was no longer spoken, but was still in religious use. Elam was an ancient civilization located to the east of Mesopotamia, in the Old Elamite period, Elam consisted of kingdoms on the Iranian plateau, centered in Anshan, and from the mid-2nd millennium BC, it was centered in Susa in the Khuzestan lowlands. Its culture played a role in the Gutian Empire and especially during the Achaemenid dynasty that succeeded it
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Longshan culture
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The first archaeological find of this culture took place at the Chengziya Archaeological Site in 1928, with the first excavations in 1930 and 1931. The culture is named after the modern town of Longshan in Zhangqiu. The culture was noted for its polished black pottery. The population expanded dramatically during the 3rd millennium BC, with settlements having rammed earth walls. It decreased in most areas around 2000 BC until the area evolved into the Bronze Age Erlitou culture. A distinctive feature of the Longshan culture was the level of skill in pottery making, including the use of pottery wheels. This pottery was widespread in North China, and also found in the Yangtze River valley, until the 1950s, such black pottery was considered the principal diagnostic, and all of these sites were assigned to the Longshan culture. For example, the culture of the lower Yangtze area is now described as the Liangzhu culture. At the same time, researchers recognized the diversity within the Yellow River valley by distinguishing regional variants in Henan, Shanxi and Shaanxi from the Shandong or classic Longshan. Also in the 1980s, Yan Wenming proposed the term Longshan era to encompass cultures of the late Neolithic across the area, the most important crop was foxtail millet, but traces of broomcorn millet, rice and wheat have also been found. Rice grains have been found in Shandong and southern Henan, specialized tools for digging, harvesting and grinding grain have been recovered. The most common source of meat was the pig, sheep and goats were apparently domesticated in the Loess Plateau area in the 4th millennium BC, found in western Henan by 2800 BC, and then spread across the middle and lower Yellow River area. Dogs were also eaten, particularly in Shandong, though cattle were less important, small-scale production of silk by raising and domesticating the silkworm in early sericulture was also known. Remains have been found in Shaanxi and southern Henan of scapulae of cattle, pigs, sheep, evidence of human sacrifice becomes more common in Shaanxi and the Central Plain in the late Longshan period. Excavations in the 1950s in Shanxian, western Henan, identified a Miaodigou II phase transitional between the preceding Yangshao culture and the later Henan Longshan, some scholars argue that the late Dawenkou culture should be considered the early phase of the Shandong Longshan culture. Miaodigou II sites are found in central and western Henan, southern Shanxi, the tools and pottery found at these sites were significantly improved from those of the preceding Yangshao culture. Agriculture was intensified, and the consumption of domesticated animals greatly increased, similarities in ceramic styles of central Henan Miaodigou II with the late Dawenkou culture to the east and the late Qujialing culture to the south suggest trade contacts between the regions. There were also expansions from middle and late Dawenkou sites toward central Henan, the late period of the Longshan culture in the middle Yellow River area is contemporaneous with the classic Shandong Longshan culture
