1.
Quebracho tree
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Quebracho is a common name in Spanish to describe very hard wood tree species. The etymology of the derived from quiebrahacha, or quebrar hacha. There are at least three similar commercially important tree species grow in the Gran Chaco region of South America. These species provide tannin and a hard, durable timber. Quebracho is sometimes used as a name for the tannin derived from the trees or their timber. Other species with less economical significance are also known as quebracho and could be found in other areas of Latin America, Astronium fraxinifolium Schott, Anacardiaceae. Colombia Krugiodendron ferreum Urban, Rhamnaceae, Br, Honduras Lonchocarpus michelianus Pittier, Leguminosae, Salvador Lysiloma acapulcense Benth. Leguminosae, Salvador Piptadenia constricta MacBride, Leguminosae, Salvador Sloanea sp, elaeocarpaceae, Jamaica Tabebuia chrysantha Nicholson, Bignoniaceae, Honduras Tecoma sp. Bignoniaceae, Honduras as Quebracho blanco Aspidosperma sp, apocynaceae, Paraguay, Argentina Poeppigia procera Presl. Leguminosae, Salvador Schinopsis haenkeana, Anacardiaceae, Argentina and Bolivia, apocynaceae, Paraguay, Argentina Schinopsis heterophylla, the Quebracho colorado mestizo as Quebracho de cerro Diphysa robinioides Benth. Leguminosae, Honduras Quebracho wood from Schinopsis spp is red-colored and very hard, logs are inserted into planers to produce chips that are used to produce the quebracho extract by boiling them in vats. It is used for leather tanning and imparts a red-brown color. Ordinary or warm soluble quebracho is the extract obtained directly from the quebracho wood. This type of extract is rich in condensed tannins of natural high molecular weight and its use is therefore limited to addition of small amounts during the process of tanning leather intended for shoe soles in hot liquids to improve the yield and the water-proofness of the leather. The cold soluble extracts are obtained by subjecting the ordinary extract to a process which transforms the phlobaphenes into completely soluble tannins. The cold soluble extracts are the most universally known and used types. The chemical structure of these extracts can be described as polymers of epicatechin, the main properties of these extracts are, a very rapid penetration, a high tannin content and a relatively low percentage of non-tannins. The rather low acid and medium salt content characterise them as mild tanning extracts, Quebracho tannins give an important added value to the quality of leathers, such as vacchetta, belts and garments, making them more compact and tear resistant with a pleasant touch
2.
Stade
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Stade is a city in Lower Saxony, Germany and part of the Hamburg Metropolitan Region. It is the seat of the named after it. The city was first mentioned in a document from 994 and it includes the urban districts of Bützfleth, Hagen, Haddorf and Wiepenkathen which have a district council of their own with some autonomous decision making rights. Stade is located on the lower Elbe river and the German Timber-Frame Road, the first human settlers came to the Stade area in 30,000 BC. Since 1180 Stade belonged to the Prince-Archbishopric of Bremen, in early 1208 King Valdemar II of Denmark and his troops conquered Stade. In August Valdemar IIs cousin being in enmity with the king, in 1209 Emperor Otto IV persuaded his ally Valdemar II to withdraw into the north of the Elbe, and the deposed Prince-Archbishop Valdemar took Stade. On 2 May 1209 Otto IV granted important town privileges to Stade, Otto IV confirmed the burghers to be personally free and recognised them constituting a political entity of their own law, the burgenses and optimi cives of Stade. Property within the boundaries could not be subjected to feudal overlordship and was to be freely inherited without feudal claims to reversion. Fair juridical procedures were constituted and maximal fines fixed, Otto IV obliged himself to prevent burghers from being taken as hostages and to liberate captured burghers. After Otto IV had changed his mind and reinvested Prince-Archbishop Valdemar with the See in 1211, in 1213 Ottos elder brother Count Palatine Henry V of the Rhine, reconquered Stade for the Prince-Archbishop. In 1215 Henry repelled another Danish attack on Stade, in the winter of 1216 Valdemar II and his Danish troops, unable to take the city of Stade, ravaged the County of Stade. From then on Stade remained a part of the Prince-Archbishopric of Bremen, in medieval times, Stade was a prominent member of the Hanseatic League, but was later eclipsed by Hamburg. In 1611 the city signed a contract with Sephardic Jews, allowing the foundation of a community, in 1648, by the Treaty of Westphalia, the Prince-Archbishopric of Bremen underwent a constitutional transformation from a prince-bishopric into a monarchy, the Duchy of Bremen. The duchy and the neighboured Principality of Verden, colloquially referred to as Bremen-Verden, were granted by the Treaty of Westphalia as an appanage to the Swedish crown, Stades heyday lasted until the Thirty Years War. In 1628 Tilly conquered the town, shortly thereafter, Sweden took possession of it until 1636. After a period of Danish occupation, Sweden finally recaptured it in 1643 and was officially granted possession of it, together with the Archbishopric of Bremen. Two-thirds of the town were razed in the town fire on 26 May 1659. The town was again to the same plan
3.
Germany
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Germany, officially the Federal Republic of Germany, is a federal parliamentary republic in central-western Europe. It includes 16 constituent states, covers an area of 357,021 square kilometres, with about 82 million inhabitants, Germany is the most populous member state of the European Union. After the United States, it is the second most popular destination in the world. Germanys capital and largest metropolis is Berlin, while its largest conurbation is the Ruhr, other major cities include Hamburg, Munich, Cologne, Frankfurt, Stuttgart, Düsseldorf and Leipzig. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity, a region named Germania was documented before 100 AD. During the Migration Period the Germanic tribes expanded southward, beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation, in 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the German Revolution of 1918–1919, the Empire was replaced by the parliamentary Weimar Republic, the establishment of the national socialist dictatorship in 1933 led to World War II and the Holocaust. After a period of Allied occupation, two German states were founded, the Federal Republic of Germany and the German Democratic Republic, in 1990, the country was reunified. In the 21st century, Germany is a power and has the worlds fourth-largest economy by nominal GDP. As a global leader in industrial and technological sectors, it is both the worlds third-largest exporter and importer of goods. Germany is a country with a very high standard of living sustained by a skilled. It upholds a social security and universal health system, environmental protection. Germany was a member of the European Economic Community in 1957. It is part of the Schengen Area, and became a co-founder of the Eurozone in 1999, Germany is a member of the United Nations, NATO, the G8, the G20, and the OECD. The national military expenditure is the 9th highest in the world, the English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine. This in turn descends from Proto-Germanic *þiudiskaz popular, derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- people, the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a mine in Schöningen where three 380, 000-year-old wooden javelins were unearthed
4.
Bauxite
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Bauxite, an aluminium ore, is the worlds main source of aluminium. It consists mostly of the minerals gibbsite, boehmite and diaspore, mixed with the two iron oxides goethite and haematite, the mineral kaolinite and small amounts of anatase. In 1821 the French geologist Pierre Berthier discovered bauxite near the village of Les Baux in Provence, in 1861, French chemist Henri Sainte-Claire Deville named the mineral bauxite. Lateritic bauxites are distinguished from karst bauxite ores, the lateritic bauxites are found mostly in the countries of the tropics. They were formed by lateritization of various silicate rocks such as granite, gneiss, basalt, syenite, in comparison with the iron-rich laterites, the formation of bauxites depends even more on intense weathering conditions in a location with very good drainage. This enables the dissolution of the kaolinite and the precipitation of the gibbsite, zones with highest aluminium content are frequently located below a ferruginous surface layer. The aluminium hydroxide in the bauxite deposits is almost exclusively gibbsite. In 2009, Australia was the top producer of bauxite with almost one-third of the production, followed by China, Brazil, India. Although aluminium demand is increasing, known reserves of its bauxite ore are sufficient to meet the worldwide demands for aluminium for many centuries. Increased aluminium recycling, which has the advantage of lowering the cost in power in producing aluminium. In November 2010, Nguyen Tan Dung, the minister of Vietnam, announced that Vietnams bauxite reserves might total 11000 Mt. Bauxite is usually strip mined because it is almost always found near the surface of the terrain, as of 2010, approximately 70% to 80% of the worlds dry bauxite production is processed first into alumina and then into aluminium by electrolysis. Bauxite rocks are classified according to their intended commercial application, metallurgical, abrasive, cement, chemical. Usually, bauxite ore is heated in a vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate, the aluminium compounds in the bauxite may be present as gibbsite, boehmite or diaspore, the different forms of the aluminium component will dictate the extraction conditions. The undissolved waste, bauxite tailings, after the aluminium compounds are extracted contains iron oxides, silica, calcia, titania, after separation of the residue by filtering, pure gibbsite is precipitated when the liquid is cooled, and then seeded with fine-grained aluminium hydroxide. The gibbsite is usually converted into aluminium oxide, Al2O3, by heating in rotary kilns or fluid flash calciners to a temperature in excess of 1000oC and this aluminium oxide is dissolved at a temperature of about 960 °C in molten cryolite. Prior to the invention of this process in 1886, elemental aluminium was made by heating ore along with sodium or potassium in a vacuum
5.
France
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France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established. The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural, political, and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
6.
Iron oxide
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Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides, common rust is a form of iron oxide. Iron oxides are used as inexpensive, durable pigments in paints, coatings. Colors commonly available are in the end of the yellow/orange/red/brown/black range. When used as a coloring, it has E number E172. Limonite Iron oxide nanoparticles List of inorganic pigments Information from Nano-Oxides, http, //chemed. chem. purdue. edu/demos/demosheets/12.3. html http, //minerals. usgs. gov/minerals/pubs/commodity/iron_oxide/ CDC - NIOSH Pocket Guide to Chemical Hazards de
7.
Waste
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Waste and wastes are unwanted or unusable materials. Waste is any substance which is discarded after use, or it is worthless, defective. Examples include municipal solid waste, hazardous waste, wastewater, radioactive waste, according to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal of 1989, Art. 2, Wastes are substance or objects, which are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of national law. Wastes may be generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products, residuals recycled or reused at the place of generation are excluded. Under the Waste Framework Directive 2008/98/EC, Art,3, the European Union defines waste as an object the holder discards, intends to discard or is required to discard. For a more structural description of the Waste Directive, see the European Commissions summary and it is most commonly measured by size or weight, and there is a stark difference between the two. For example, organic waste is much heavier when it is wet, on a global scale it is difficult to report waste because countries have different definitions of waste and what falls into waste categories, as well as different ways of reporting. Based on incomplete reports from its parties, the Basel Convention estimated 338 million tonnes of waste was generated in 2001, for the same year, OECD estimated 4 billion tonnes from its member countries. Toxic waste materials can contaminate surface water, groundwater, soil, and air which causes problems for humans, other species. Waste treatment and disposal produces significant green house gas emissions, notably methane, Waste management is a significant environmental justice issue. Many of the environmental burdens cited above are often borne by marginalized groups, such as racial minorities, women. NIMBY is the opposition of residents to a proposal for a new development because it is close to them, however, the need for expansion and siting of waste treatment and disposal facilities is increasing worldwide. Environmental policies such as pay as you throw can reduce the cost of management, Waste recovery can curb economic costs because it avoids extracting raw materials and often cuts transportation costs. Economic assessment of municipal waste management systems – case studies using a combination of life-cycle assessment, the location of waste treatment and disposal facilities often reduces property values due to noise, dust, pollution, unsightliness, and negative stigma. The informal waste sector consists mostly of waste pickers who scavenge for metals, glass, plastic, textiles, and other materials and then trade them for a profit. This sector can significantly alter or reduce waste in a system, but other negative economic effects come with the disease, poverty, exploitation. Resource recovery is the retrieval of recyclable waste, which was intended for disposal and it is the processing of recyclables to extract or recover materials and resources, or convert to energy
8.
Aluminium oxide
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Aluminium oxide or aluminum oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. It is the most commonly occurring of several aluminium oxides, and it is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It occurs naturally in its crystalline polymorphic phase α-Al2O3 as the mineral corundum, varieties of form the precious gemstones ruby. Al2O3 is significant in its use to produce metal, as an abrasive owing to its hardness. Corundum is the most common naturally occurring form of aluminium oxide. Rubies and sapphires are gem-quality forms of corundum, which owe their characteristic colors to trace impurities, rubies are given their characteristic deep red color and their laser qualities by traces of chromium. Sapphires come in different colors given by various other impurities, such as iron, Al2O3 is an electrical insulator but has a relatively high thermal conductivity for a ceramic material. Aluminium oxide is insoluble in water, in its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an abrasive and as a component in cutting tools. Aluminium oxide is responsible for the resistance of aluminium to weathering. Metallic aluminium is very reactive with oxygen, and a thin passivation layer of aluminium oxide forms on any exposed aluminium surface. This layer protects the metal from further oxidation, the thickness and properties of this oxide layer can be enhanced using a process called anodising. A number of alloys, such as bronzes, exploit this property by including a proportion of aluminium in the alloy to enhance corrosion resistance. Aluminium oxide was taken off the United States Environmental Protection Agencys chemicals lists in 1988, aluminium oxide is on EPAs Toxics Release Inventory list if it is a fibrous form. Al2O3 +6 HF →2 AlF3 +3 H2O Al2O3 +2 NaOH +3 H2O →2 NaAl4 The most common form of aluminium oxide is known as corundum. The oxygen ions form a hexagonal close-packed structure with aluminium ions filling two-thirds of the octahedral interstices. In terms of its crystallography, corundum adopts a trigonal Bravais lattice with a group of R-3c. The primitive cell contains two units of aluminium oxide. Each has a crystal structure and properties
9.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
10.
Dangerous goods
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Dangerous goods or hazardous goods are solids, liquids, or gases that can harm people, other living organisms, property, or the environment. They are often subject to chemical regulations, in the United States, United Kingdom and sometimes in Canada, dangerous goods are more commonly known as hazardous materials. In the United States, dangerous goods are often indicated by diamond-shaped signage on the item, its container, mitigating the risks associated with hazardous materials may require the application of safety precautions during their transport, use, storage and disposal. Most countries regulate hazardous materials by law, and they are subject to international treaties as well. Even so, different countries may use different class diamonds for the same product, for example, in Australia, Anhydrous Ammonia UN1005 is classified as 2.3 with sub risk 8, whereas in the U. S. it is only classified as 2.2. People who handle dangerous goods will often wear protective equipment, and metropolitan fire departments often have a team specifically trained to deal with accidents. Laws and regulations on the use and handling of materials may differ depending on the activity. For example, one set of requirements may apply to their use in the workplace while a different set of requirements may apply to spill response, sale for consumer use, most countries regulate some aspect of hazardous materials. The most widely applied regulatory scheme is that for the transportation of dangerous goods, individual airline and governmental requirements are incorporated with this by the International Air Transport Association to produce the widely used IATA Dangerous Goods Regulations. Similarly, the International Maritime Organization has developed the International Maritime Dangerous Goods Code for transportation of goods by sea. IMO member countries have developed the HNS Convention to provide compensation in case of dangerous goods spills in the sea. The Intergovernmental Organisation for International Carriage by Rail has developed the Regulations concerning the International Carriage of Dangerous Goods by Rail, many individual nations have also structured their dangerous goods transportation regulations to harmonize with the UN Model in organization as well as in specific requirements. GHS will use consistent criteria for classification and labeling on a global level, Dangerous goods are divided into nine classes on the basis of the specific chemical characteristics producing the risk. Note, The graphics and text in this article representing the dangerous goods safety marks are derived from the United Nations-based system of identifying dangerous goods, not all countries use precisely the same graphics in their national regulations. Some use graphic symbols, but without English wording or with similar wording in their national language, refer to the Dangerous Goods Transportation Regulations of the country of interest. For example, see the TDG Bulletin, Dangerous Goods Safety Marks based on the Canadian Transportation of Dangerous Goods Regulations, the statement above applies equally to all the Dangerous Goods classes discussed in this article. Australia uses the standard international UN numbers with a few slightly different signs on the back, front, the country uses the same Hazchem code system as the UK to provide advisory information to emergency services personnel in the event of an emergency. New Zealands Land Transport Rule, Dangerous Goods 2005 and the Dangerous Goods Amendment 2010 describe the rules applied to the transportation of hazardous and dangerous goods in New Zealand
11.
Mining
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Mining is extraction of valuable minerals or other geological materials from the earth usually from an orebody, lode, vein, seam, reef or placer deposits. These deposits form a mineralized package that is of economic interest to the miner, ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Mining of stones and metal has been a human activity since pre-historic times, Mining operations usually create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the nations have passed regulations to decrease the impact. Work safety has long been a concern as well, and modern practices have significantly improved safety in mines, levels of metals recycling are generally low. Unless future end-of-life recycling rates are stepped up, some rare metals may become unavailable for use in a variety of consumer products, due to the low recycling rates, some landfills now contain higher concentrations of metal than mines themselves. Since the beginning of civilization, people have used stone, ceramics and, later and these were used to make early tools and weapons, for example, high quality flint found in northern France, southern England and Poland was used to create flint tools. Flint mines have been found in areas where seams of the stone were followed underground by shafts. The mines at Grimes Graves and Krzemionki are especially famous, other hard rocks mined or collected for axes included the greenstone of the Langdale axe industry based in the English Lake District. The oldest-known mine on archaeological record is the Lion Cave in Swaziland, at this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of an age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons. Ancient Egyptians mined malachite at Maadi, at first, Egyptians used the bright green malachite stones for ornamentations and pottery. Later, between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were found at Wadi Hammamat, Tura, Aswan and various other Nubian sites on the Sinai Peninsula. Mining in Egypt occurred in the earliest dynasties, the gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one used to break down the hard rock holding the gold. One of the complexes is shown in one of the earliest known maps, the miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust
12.
Bayer process
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The Bayer process is the principal industrial means of refining bauxite to produce alumina. Bauxite, the most important ore of aluminium, contains only 30–54% aluminium oxide, Al2O3, the rest being a mixture of silica, various iron oxides, the aluminium oxide must be purified before it can be refined to aluminium metal. In the Bayer process, bauxite ore is heated in a vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate in an extraction process, the aluminium compounds in the bauxite may be present as gibbsite, boehmite or diaspore, the different forms of the aluminium component will dictate the extraction conditions. After separation of the residue by filtering, gibbsite is precipitated when the liquid is cooled, sometimes lime is added at this stage to precipitate the silica as calcium silicate. The solution is clarified by filtering off the impurities, commonly with a rotary sand trap and with the aid of a flocculant such as starch. The undissolved waste after the aluminium compounds are extracted, bauxite tailings, contains iron oxides, silica, calcia, titania and this, however, allows gallium and vanadium impurities to build up in the liquors, so these can be extracted. For bauxites having more than 10% silica, the Bayer process becomes uneconomic due to insoluble sodium aluminium silicate being formed, which reduces yield, over 90% of the aluminium oxide so produced is used in the Hall–Héroult process to produce aluminium. The Bayer process was invented in 1888 by Carl Josef Bayer and this process was abandoned in favor of the Bayer process. The process began to gain importance in metallurgy together with the invention of the Hall–Héroult electrolytic aluminium process, together with the cyanidation process invented in 1887, the Bayer process marks the birth of the modern field of hydrometallurgy. Today, the process is virtually unchanged and it nearly all the worlds alumina supply as an intermediate step in aluminium production. In 2010, large amounts of red mud waste products were discharged into the Danube river during the Ajka alumina plant accident. Hall–Héroult process Ajka alumina plant accident Deville process Habashi, F
13.
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
14.
Red
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Red is the color at the longer-wavelengths end of the spectrum of visible light next to orange, at the opposite end from violet. Red color has a predominant light wavelength of roughly 620–740 nanometers, light with a longer wavelength than red but shorter than terahertz radiation and microwave is called infrared. Red is one of the secondary colors, resulting from the combination of yellow. Traditionally, it was viewed as a primary colour, along with yellow and blue, in the RYB color space and traditional color wheel formerly used by painters. Reds can vary in shade from light pink to very dark maroon or burgundy. Red is the color of cyan. In nature, the red color of blood comes from hemoglobin, the red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. It also causes the red color of the planet Mars, the color of autumn leaves is caused by pigments called anthocyanins, which are produced towards the end of summer, when the green chlorophyll is no longer produced. One to two percent of the population has red hair, the color is produced by high levels of the reddish pigment pheomelanin. Since red is the color of blood, it has historically been associated with sacrifice, danger, modern surveys in the United States and Europe show red is also the color most commonly associated with heat, activity, passion, sexuality, anger, love and joy. In China, India and many other Asian countries it is the color of symbolizing happiness, since the 19th century, red has also been associated with socialism and communism. The word red is derived from the Old English rēad, the word can be further traced to the Proto-Germanic rauthaz and the Proto-Indo European root rewdʰ-. In Sanskrit, the word means red or blood. In the Akkadian language of Ancient Mesopotamia and in the modern Inuit language of Inuit, the words for colored in Latin and Spanish both also mean red. In Portuguese the word for red is vermelho, which comes from Latin vermiculus, in the Russian language, the word for red, Кра́сный, comes from the same old Slavic root as the words for beautiful—красивый and excellent—прекрасный. Thus Red Square in Moscow, named long before the Russian Revolution, in heraldry, the word gules is used for red. Red can vary in hue from orange-red to violet-red, and for each hue there is a variety of shades and tints. Red hematite powder was found scattered around the remains at a grave site in a Zhoukoudian cave complex near Beijing
15.
PH
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In chemistry, pH is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the concentration, measured in units of moles per liter. More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH7, being neither an acid nor a base, contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement, the pH of aqueous solutions can be measured with a glass electrode and a pH meter, or an indicator. In the first papers, the notation had the H as a subscript to the p, as so. The exact meaning of the p in pH is disputed, but according to the Carlsberg Foundation and it has also been suggested that the p stands for the German Potenz, others refer to French puissance. Another suggestion is that the p stands for the Latin terms pondus hydrogenii, potentia hydrogenii and it is also suggested that Sørensen used the letters p and q simply to label the test solution and the reference solution. Currently in chemistry, the p stands for decimal cologarithm of, PH is defined as the decimal logarithm of the reciprocal of the hydrogen ion activity, aH+, in a solution. P H = − log 10 = log 10 For example and this definition was adopted because ion-selective electrodes, which are used to measure pH, respond to activity. For H+ number of electrons transferred is one and it follows that electrode potential is proportional to pH when pH is defined in terms of activity. The reference electrode may be a silver chloride electrode or a calomel electrode, the hydrogen-ion selective electrode is a standard hydrogen electrode. Reference electrode | concentrated solution of KCl || test solution | H2 | Pt Firstly, the cell is filled with a solution of hydrogen ion activity. Then the emf, EX, of the cell containing the solution of unknown pH is measured. PH = pH + E S − E X z The difference between the two measured emf values is proportional to pH and this method of calibration avoids the need to know the standard electrode potential. The proportionality constant, 1/z is ideally equal to 12.303 R T / F the Nernstian slope, to apply this process in practice, a glass electrode is used rather than the cumbersome hydrogen electrode. A combined glass electrode has a reference electrode. It is calibrated against buffer solutions of hydrogen ion activity
16.
Aluminium hydroxide
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Aluminium hydroxide, Al3, is found in nature as the mineral gibbsite and its three much rarer polymorphs, bayerite, doyleite and nordstrandite. Aluminium hydroxide is amphoteric in nature, i. e, it has both basic and acidic nature, closely related are aluminium oxide hydroxide, AlO, and aluminium oxide, Al2O3. Aluminium oxide is amphoteric in nature. These compounds together are the components of the aluminium ore bauxite. The naming for the different forms of aluminium hydroxide is ambiguous, all four polymorphs have a chemical composition of aluminium trihydroxide. Gibbsite is also known as hydrargillite, named after the Greek words for water, in 1930 it was referred to as α-alumina trihydrate to contrast it with bayerite which was called β-alumina trihydrate. In 1957 a symposium on alumina nomenclature attempted to develop a standard, resulting in gibbsite being designated γ-Al3 and bayerite becoming α-Al3. Gibbsite has a metal hydroxide structure with hydrogen bonds. It is built up of layers of hydroxyl groups with aluminium ions occupying two-thirds of the octahedral holes between the two layers. It dissolves in acid, forming 3+ or its hydrolysis products and it also dissolves in strong alkaline solutions, forming −. Under most conditions gibbsite is the most chemically stable form of aluminium hydroxide, all forms of Al3 crystals are hexagonal. Virtually all the aluminium hydroxide used commercially is manufactured by the Bayer process which involves dissolving bauxite in sodium hydroxide at temperatures up to 270 °C, the waste solid, bauxite tailings, is removed and aluminium hydroxide is precipitated from the remaining solution of sodium aluminate. This aluminium hydroxide can be converted to oxide or alumina by calcination. The residue or bauxite tailings, which is iron oxide, is highly caustic due to residual sodium hydroxide. It was historically stored in lagoons, this led to the Ajka alumina plant accident in 2010 in Hungary, an additional 122 sought treatment for chemical burns. The mud contaminated 40 square kilometers of land and reached the Danube, while the mud was considered non-toxic due to low levels of heavy metals, the associated slurry had a very high pH of 13. Annual production in 2015 was approximately 170 million tonnes, over 90% of which is converted to aluminium oxide that is used in the manufacture of aluminium metal, freshly precipitated aluminium hydroxide forms gels, which are the basis for the application of aluminium salts as flocculants in water purification. Aluminium hydroxide gels can be dehydrated to form an amorphous aluminium hydroxide powder, aluminium hydroxide also finds use as a fire retardant filler for polymer applications in a similar way to magnesium hydroxide and mixtures of huntite and hydromagnesite
17.
Gibbsite
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Gibbsite, Al3, is one of the mineral forms of aluminium hydroxide. It is often designated as γ-Al3 and it is also sometimes called hydrargillite. Gibbsite is an important ore of aluminium in that it is one of three phases that make up the rock bauxite. Gibbsite has three named structural polymorphs or polytypes, bayerite, doyleite, and nordstrandite, Gibbsite and bayerite are monoclinic, whereas doyleite and nordstrandite are triclinic forms. The structure of gibbsite is interesting and analogous to the structure of the micas. The basic structure forms stacked sheets of linked octahedrons of aluminium hydroxide, the octahedrons are composed of aluminium ions with a +3 charge bonded to six octahedrally coordinated hydroxides with a -1 charge. Each of the hydroxides is bonded to only two aluminium atoms because one third of the octahedrons are vacant a central aluminium, the result is a neutral sheet since +3/6 = +1/2 and -1/2 = -1/2, thus the charges cancel. The lack of a charge on the gibbsite sheets means that there is no charge to retain ions between the sheets and act as a glue to keep the sheets together. The sheets are held together by weak residual bonds and this results in a very soft easily cleaved mineral. Gibbsites structure is related to the structure of brucite, Mg2. However the lower charge in brucites magnesium as opposed to gibbsites aluminium does not require one third of the octahedrons be vacant of a central ion in order to maintain a neutral sheet. The different symmetry of gibbsite and brucite is due to the different way that the layers are stacked and it is the gibbsite layer that in a way forms the floor plan for the mineral corundum, Al2O3. The basic structure of corundum is identical to gibbsite except the hydroxides are replaced by oxygen, Gibbsite is interesting for another reason because it is often found as a part of the structure of other minerals. The neutral aluminium hydroxide sheets are found sandwiched between sheets in important clay groups, the illite, kaolinite, and montmorillonite/smectite groups. The individual aluminium hydroxide layers are identical to the layers of gibbsite and are referred to as the gibbsite layers. Gibbsite is named after George Gibbs, an American mineral collector, hurlbut, Cornelius S. Klein, Cornelis,1985, Manual of Mineralogy, 20th ed. ISBN 0-471-80580-7 Webmineral Gibbsite
18.
Boehmite
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Boehmite or böhmite is an aluminium oxide hydroxide mineral, a component of the aluminium ore bauxite. It crystallizes in the orthorhombic system and is typically massive in habit. It is white with tints of yellow, green, brown or red due to impurities and it has a vitreous to pearly luster, a Mohs hardness of 3 to 3.5 and a specific gravity of 3.00 to 3.07. It is colorless in thin section, optically biaxial positive with refractive indices of nα =1.644 -1.648, nβ =1.654 -1.657, Boehmite occurs in tropical laterites and bauxites developed on alumino-silicate bedrock. It also occurs as an alteration product of corundum and nepheline. It occurs with kaolinite, gibbsite and diaspore in bauxite deposits, industrially, it is used as an inexpensive flame retardant additive for fire-safe polymers. It was first described by J. Steven Dutch,2002, Lepidocrocite and Boehmite Structure, University of Wisconsin - Green Bay
19.
Diaspore
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It occurs sometimes as flattened crystals, but usually as lamellar or scaly masses, the flattened surface being a direction of perfect cleavage on which the lustre is markedly pearly in character. It is colorless or greyish-white, yellowish, sometimes violet in color and it may be readily distinguished from other colorless transparent minerals with a perfect cleavage and pearly luster—like mica, talc, brucite, and gypsum— by its greater hardness of 6.5 -7. When heated before the blowpipe it decrepitates violently, breaking up into white pearly scales, the mineral occurs as an alteration product of corundum or emery and is found in granular limestone and other crystalline rocks. Well-developed crystals are found in the deposits of the Urals and at Chester, Massachusetts. If obtainable in large quantity, it would be of importance as a source of aluminium. Diaspore, along with gibbsite and boehmite, is a component of the aluminium ore bauxite. It was first described in 1801 for an occurrence in Mramorsk Zavod, Sverdlovskaya Oblast, Middle Urals, the name, which was coined by René Just Haüy, is from the Greek for διασπείρειν, to scatter, in allusion to its decrepitation on heating. Csarite, ottomanite, and zultanite are trade names for gem-quality diaspore from the İlbir Mountains of southwest Turkey
20.
Sodalite
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Sodalite is a rich royal blue tectosilicate mineral widely used as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are transparent to translucent. Sodalite is a member of the group with hauyne, nosean. A light, relatively hard yet fragile mineral, sodalite is named after its sodium content, well known for its blue color, sodalite may also be grey, yellow, green, or pink and is often mottled with white veins or patches. The more uniformly blue material is used in jewellery, where it is fashioned into cabochons, lesser material is more often seen as facing or inlay in various applications. Although somewhat similar to lazurite and lapis lazuli, sodalite rarely contains pyrite and it is further distinguished from similar minerals by its white streak. Sodalites six directions of cleavage may be seen as incipient cracks running through the stone. It is sometimes referred to as poor mans lapis due to its similar color and its name comes from its high sodium content. Most sodalite will fluoresce orange under ultraviolet light, and hackmanite exhibits tenebrescence, hackmanite is an important variety of sodalite exhibiting tenebrescence. When hackmanite from Mont Saint-Hilaire or Ilímaussaq is freshly quarried, it is pale to deep violet. Conversely, hackmanite from Afghanistan and the Myanmar Republic starts off creamy white, if left in a dark environment for some time, the violet will fade again. Tenebrescence is accelerated by the use of longwave or, particularly, much sodalite will also fluoresce a patchy orange under UV light. Sodalite was first described in 1811 for the occurrence in its locality in the Ilimaussaq complex, Narsaq. Occurring typically in massive form, sodalite is found as fillings in plutonic igneous rocks such as nepheline syenites. It is associated with other minerals typical of undersaturated environments, namely leucite, cancrinite and natrolite, other associated minerals include nepheline, titanian andradite, aegirine, microcline, sanidine, albite, calcite, fluorite, ankerite and baryte. Significant deposits of material are restricted to but a few locales, Bancroft, Ontario, and Mont-Saint-Hilaire, Quebec, in Canada, and Litchfield, Maine. The Ice River complex, near Golden, British Columbia, contains sodalite, smaller deposits are found in South America, Portugal, Romania, Burma and Russia. Hackmanite is found principally in Mont-Saint-Hilaire and Greenland, euhedral, transparent crystals are found in northern Namibia and in the lavas of Vesuvius, Italy
21.
Goethite
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Goethite, is an iron bearing hydroxide mineral of the diaspore group, is found in soil and other low-temperature environments. Goethite has been known since ancient times for its use as a pigment. Evidence has been found of its use in paint pigment samples taken from the caves of Lascaux in France and it was first described in 1806 based on samples found in the Hollertszug Mine in Herdorf, Germany. The mineral was named after the German polymath and poet Johann Wolfgang von Goethe, in 2003, nanoparticulate authigenic goethite was shown to be the most common diagenetic iron oxyhydroxide in both marine and lake sediments. Goethite is an iron oxyhydroxide containing ferric iron and it is the main component of rust and bog iron ore. Goethites hardness ranges from 5.0 to 5.5 on the Mohs Scale, the mineral forms prismatic needle-like crystals, but is more typically massive. Feroxyhyte and lepidocrocite are both polymorphs of the iron oxyhydroxide FeO, although they have the same chemical formula as goethite, their different crystalline structures make them distinct minerals. Goethite often forms through the weathering of other minerals, and thus is a common component of soils. The formation of goethite is marked by the state change of Fe2+ to Fe3+. Because of this state change, goethite is commonly seen as a pseudomorph. As iron-bearing minerals are brought to the zone of oxidation within the soil and it may also be precipitated by groundwater or in other sedimentary conditions, or form as a primary mineral in hydrothermal deposits. Goethite has also found to be produced by the excretion processes of certain bacteria types. Goethite is found all over the planet, usually in the form of concretions, stalactitic formations, oolites and it is also a very common pseudomorph. It is frequently encountered in the areas at the head of spring waters, on cave floors. The boxworks or gossan resulting from the oxidation of ore deposits is formed of goethite along with other iron oxides. Significant deposits of goethite are found in England, Australia, Cuba, and Michigan, Minnesota, Missouri, Colorado, Alabama, Georgia, Virginia, and Tennessee, and Florida caves in the United States. In 2015 it was reported that limpets teeth have goethite fibres in them and its main modern use is as an iron ore, being referred to as brown iron ore. It does have some use as an earth pigment
22.
Hematite
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Hematite, also spelled as haematite, is the mineral form of iron oxide, one of several iron oxides. Hematite crystallizes in the lattice system, and it has the same crystal structure as ilmenite. Hematite and ilmenite form a solid solution at temperatures above 950 °C. Hematite is colored black to steel or silver-gray, brown to reddish brown and it is mined as the main ore of iron. Varieties include kidney ore, martite, iron rose and specularite, while the forms of hematite vary, they all have a rust-red streak. Hematite is harder than iron, but much more brittle. Maghemite is a hematite- and magnetite-related oxide mineral, huge deposits of hematite are found in banded iron formations. Gray hematite is typically found in places that can have still standing water or mineral hot springs, the mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, however, usually as the result of volcanic activity, the name hematite is derived from the Greek word for blood αἷμα haima, due to the red coloration found in some varities of hematite. The color of hematite lends itself to use as a pigment, ochre is a clay that is colored by varying amounts of hematite, varying between 20% and 70%. Red ochre contains unhydrated hematite, whereas yellow ochre contains hydrated hematite, the principal use of ochre is for tinting with a permanent color. The red chalk writing of this mineral was one of the earliest in the history of humans, the powdery mineral was first used 164,000 years ago by the Pinnacle-Point man possibly for social purposes. Hematite residues are found in graves from 80,000 years ago. Near Rydno in Poland and Lovas in Hungary red chalk mines have been found that are from 5000 BC, rich deposits of hematite have been found on the island of Elba that have been mined since the time of the Etruscans. Adding to the surprise was a transition with a decrease in temperature at around 260 K to a phase with no net magnetic moment. The disappearance of the moment with a decrease in temperature at 260 K is caused by a change in the anisotropy which causes the moments to align along the c axis, in this configuration, spin canting does not reduce the energy. The magnetic properties of bulk hematite differ from their nanoscale counterparts, for example, the Morin transition temperature of hematite decreases with a decrease in the particle size. Two other end-members are referred to as protohematite and hydrohematite, enhanced magnetic coercivities for hematite have been achieved by dry-heating a 2-line ferrihydrite precursor prepared from solution
23.
Titanium dioxide
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Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO2. When used as a pigment, it is called white, Pigment White 6. Generally it is sourced from ilmenite, rutile and anatase and it has a wide range of applications, from paint to sunscreen to food coloring. When used as a coloring, it has E number E171. World production in 2014 exceeded 9 million metric tons, one of these is known as akaogiite and should be considered as an extremely rare mineral. It is mainly sourced from ilmenite ore and this is the most widespread form of titanium dioxide-bearing ore around the world. Rutile is the next most abundant and contains around 98% titanium dioxide in the ore, the metastable anatase and brookite phases convert irreversibly to the equilibrium rutile phase upon heating above temperatures in the range 600–800 °C. Dubrovinsky and co-authors to be the hardest known oxide with the Vickers hardness of 38 GPa, however, later studies came to different conclusions with much lower values for both the hardness and bulk modulus. The oxides are commercially important ores of titanium, the metal can also be mined from other minerals such as ilmenite or leucoxene ores, or one of the purest forms, rutile beach sand. Star sapphires and rubies get their asterism from rutile impurities present in them, Titanium dioxide is found as a mineral in magmatic rocks and hydrothermal veins, as well as weathering rims on perovskite. TiO2 also forms lamellae in other minerals, spectral lines from titanium oxide are prominent in class M stars, which are cool enough to allow molecules of this chemical to form. The production method depends on the feedstock, the most common method for the production of titanium dioxide utilizes the mineral ilmenite. Ilmenite is mixed with sulfuric acid and this reacts to remove the iron oxide group in the ilmenite. The by-product iron sulfate is crystallized and filtered-off to yield only the salt in the digestion solution. This product is called synthetic rutile and this is further processed in a similar way to rutile to give the titanium dioxide product. Synthetic rutile and titanium slags are made especially for titanium dioxide production, the use of ilminite ore usually only produces pigment grade titanium dioxide. Another method for the production of synthetic rutile from ilmenite utilizes the Becher Process, rutile is the second most abundant mineral sand. Rutile found in primary rock cannot be extracted hence the deposits containing rutile sand can be mined meaning a reduced availability to the high concentration ore, crude titanium dioxide is purified via converting to titanium tetrachloride in the chloride process
24.
Muscovite
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Muscovite is a hydrated phyllosilicate mineral of aluminium and potassium with formula KAl22, or 236. It has a perfect basal cleavage yielding remarkably thin laminae which are often highly elastic. Sheets of muscovite 5 m ×3 m have been found in Nellore, Muscovite has a Mohs hardness of 2–2.25 parallel to the face,4 perpendicular to the and a specific gravity of 2. 76–3. It can be colorless or tinted through grays, browns, greens, yellows, or violet or red and it is anisotropic and has high birefringence. The green, chromium-rich variety is called fuchsite, mariposite is also a type of muscovite. In pegmatites, it is found in immense sheets that are commercially valuable. Muscovite is in demand for the manufacture of fireproofing and insulating materials, the name muscovite comes from Muscovy-glass, a name given to the mineral in Elizabethan England due to its use in medieval Russia as a cheaper alternative to glass in windows. Media related to Muscovite at Wikimedia Commons
25.
Calcium carbonate
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Calcium carbonate is a chemical compound with the formula CaCO3. It is a substance found in rocks as the minerals calcite and aragonite and is the main component of pearls and the shells of marine organisms, snails. Calcium carbonate is the ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a supplement or as an antacid. Calcium carbonate shares the properties of other carbonates. CaCO3 + CO2 + H2O → Ca2 This reaction is important in the erosion of rock, forming caverns. An unusual form of calcium carbonate is the hexahydrate, ikaite, ikaite is stable only below 6 °C. The vast majority of calcium used in industry is extracted by mining or quarrying. Pure calcium carbonate, can be produced from a quarried source. Alternatively, calcium carbonate is prepared from calcium oxide, other forms can be prepared, the denser, orthorhombic λ-CaCO3 and μ-CaCO3, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C, calcite contains calcium atoms coordinated by 6 oxygen atoms, in aragonite they are coordinated by 9 oxygen atoms. The vaterite structure is not fully understood, magnesium carbonate MgCO3 has the calcite structure, whereas strontium and barium carbonate adopt the aragonite structure, reflecting their larger ionic radii. Calcite, aragonite and vaterite are pure calcium carbonate minerals, industrially important source rocks which are predominantly calcium carbonate include limestone, chalk, marble and travertine. Eggshells, snail shells and most seashells are predominantly calcium carbonate, oyster shells have enjoyed recent recognition as a source of dietary calcium, but are also a practical industrial source. While not practical as a source, dark green vegetables such as broccoli. Beyond Earth, strong evidence suggests the presence of Calcium carbonate on Mars, signs of Calcium Carbonate have been detected at more than one location. This provides some evidence for the past presence of liquid water, Carbonate is found frequently in geologic settings and constitute an enormous carbon reservoir. Calcium carbonate occurs as aragonite, calcite and dolomite, the carbonate minerals form the rock types, limestone, chalk, marble, travertine, tufa, and others
26.
Kaolinite
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Kaolinite /ˈkeɪəlᵻˌnaɪt/ is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O54. It is a silicate mineral, with one tetrahedral sheet of silica linked through oxygen atoms to one octahedral sheet of alumina octahedra. Rocks that are rich in kaolinite are known as kaolin /ˈkeɪəlᵻn/ or china clay, the name kaolin is derived from Gaoling, a Chinese village near Jingdezhen in southeastern Chinas Jiangxi Province. The name entered English in 1727 from the French version of the word, kaolin, kaolinite has a low shrink–swell capacity and a low cation-exchange capacity. It is a soft, earthy, usually white, mineral, in many parts of the world it is colored pink-orange-red by iron oxide, giving it a distinct rust hue. Lighter concentrations yield white, yellow, or light orange colors, alternating layers are sometimes found, as at Providence Canyon State Park in Georgia, United States. Commercial grades of kaolin are supplied and transported as dry powder, kaolinite group clays undergo a series of phase transformations upon thermal treatment in air at atmospheric pressure. Below 100 °C, exposure to dry air will slowly remove liquid water from the kaolin, the end-state for this transformation is referred to as leather dry. Between 100 °C and about 550 °C, any remaining water is expelled from kaolinite. The end state for this transformation is referred to as bone dry, throughout this temperature range, the expulsion of water is reversible, if the kaolin is exposed to liquid water, it will be reabsorbed and disintegrate into its fine particulate form. Subsequent transformations are not reversible, and represent permanent chemical changes, endothermic dehydration of kaolinite begins at 550–600 °C producing disordered metakaolin, but continuous hydroxyl loss is observed up to 900 °C. Al2Si2O54 → Al2Si2O7 +2 H2O, further heating to 925–950 °C converts metakaolin to an aluminium-silicon spinel which is sometimes also referred to as a gamma-alumina type structure,2 Al2Si2O7 → Si3Al4O12 + SiO2. Upon calcination above 1050 °C, the spinel phase nucleates and transforms to platelet mullite, finally, at 1400 °C the needle form of mullite appears, offering substantial increases in structural strength and heat resistance. This is a structural but not chemical transformation, see stoneware for more information on this form. Kaolinite clay occurs in abundance in soils that have formed from the weathering of rocks in hot. Such climatically-related differences in mineral content are often used to infer changes in climates in the geological past. In the Institut National pour lEtude Agronomique au Congo Belge classification system, in the US the main kaolin deposits are found in central Georgia, on a stretch of the Atlantic Seaboard fall line between Augusta and Macon. The deposits were formed between the late Cretaceous and early Paleogene, about 100 million to 45 million years ago, in sediments derived from weathered igneous, Kaolin production in the US during 2011 was 5.5 million tonnes
27.
Alkalinity
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Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid. Measuring alkalinity is important in determining a streams ability to neutralize acidic pollution from rainfall or wastewater and it is one of the best measures of the sensitivity of the stream to acid inputs. There can be changes in the alkalinity of streams and rivers in response to human disturbances. Alkalinity is related to the pH of a solution, but measures a different property, roughly, the alkalinity of a solution is a measure of how strong the bases are in a solution, whereas the pH measures the amount of chemical bases. A good example is a solution, which can have many available bases despite having only a moderate pH level. Alkalinity roughly refers to the amount of bases in a solution that can be converted to uncharged species by a strong acid. The cited author, James Drever, provides an equation expressed in terms of molar equivalents, which means the number of moles of each ion type multiplied by the charge of the ion. For example,1 mole of HCO31− in solution represents 1 molar equivalent, the total charge of a solution always equals zero. On the left-hand side of the equation is the sum of conservative cations minus the sum of conservative anions, balancing this on the right side is the sum of the anions that could be neutralized by added H+ ions minus H+ ions already present, as indicated by the pH. This right side term is called total alkalinity and it is, quoting Drever, formally defined as the equivalent sum of the bases that are titratable with strong acid. The listing of ions shown on the right in Drever was mHCO3− + 2mCO32− + mB4− + mH34− + mHS− + morganic anions + mOH− - mH+, total alkalinity is measured by adding a strong acid until all the anions listed above are converted to uncharged species. The total alkalinity is not affected by temperature, pressure, or pH, though the values of individual constituents are, Drever further notes that in most natural waters, all ions except HCO3− and CO3−2 have low concentrations. Thus carbonate alkalinity, which is equal to mHCO3− + 2mCO3−2 is also equal to the total alkalinity. Alkalinity or AT measures the ability of a solution to neutralize acids to the point of carbonate or bicarbonate. The alkalinity is equal to the sum of the bases in solution. Other common natural components that can contribute to alkalinity include borate, hydroxide, phosphate, silicate, dissolved ammonia, the bases of some organic acids. Solutions produced in a laboratory may contain a virtually limitless number of bases that contribute to alkalinity, Alkalinity is usually given in the unit mEq/L. Commercially, as in the pool industry, alkalinity might also be given in parts per million of equivalent calcium carbonate
28.
Hungary
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Hungary is a unitary parliamentary republic in Central Europe. With about 10 million inhabitants, Hungary is a member state of the European Union. The official language is Hungarian, which is the most widely spoken language in Europe. Hungarys capital and largest metropolis is Budapest, a significant economic hub, major urban areas include Debrecen, Szeged, Miskolc, Pécs and Győr. His great-grandson Stephen I ascended to the throne in 1000, converting the country to a Christian kingdom, by the 12th century, Hungary became a middle power within the Western world, reaching a golden age by the 15th century. Hungarys current borders were established in 1920 by the Treaty of Trianon after World War I, when the country lost 71% of its territory, 58% of its population, following the interwar period, Hungary joined the Axis Powers in World War II, suffering significant damage and casualties. Hungary became a state of the Soviet Union, which contributed to the establishment of a four-decade-long communist dictatorship. On 23 October 1989, Hungary became again a democratic parliamentary republic, in the 21st century, Hungary is a middle power and has the worlds 57th largest economy by nominal GDP, as well as the 58th largest by PPP, out of 188 countries measured by the IMF. As a substantial actor in several industrial and technological sectors, it is both the worlds 36th largest exporter and importer of goods, Hungary is a high-income economy with a very high standard of living. It keeps up a security and universal health care system. Hungary joined the European Union in 2004 and part of the Schengen Area since 2007, Hungary is a member of the United Nations, NATO, WTO, World Bank, the AIIB, the Council of Europe and Visegrád Group. Well known for its cultural history, Hungary has been contributed significantly to arts, music, literature, sports and science. Hungary is the 11th most popular country as a tourist destination in Europe and it is home to the largest thermal water cave system, the second largest thermal lake in the world, the largest lake in Central Europe, and the largest natural grasslands in Europe. The H in the name of Hungary is most likely due to historical associations with the Huns. The rest of the word comes from the Latinized form of Medieval Greek Oungroi, according to an explanation the Greek name was borrowed from Proto-Slavic Ǫgǔri, in turn borrowed from Oghur-Turkic Onogur. Onogur was the name for the tribes who later joined the Bulgar tribal confederacy that ruled the eastern parts of Hungary after the Avars. The Hungarians likely belonged to the Onogur tribal alliance and it is possible they became its ethnic majority. The Hungarian endonym is Magyarország, composed of magyar and ország, the word magyar is taken from the name of one of the seven major semi-nomadic Hungarian tribes, magyeri
29.
Ajka alumina plant accident
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The Ajka alumina sludge spill was an industrial accident at a caustic waste reservoir chain of the Ajkai Timföldgyár alumina plant in Ajka, Veszprém County, in western Hungary. On 4 October 2010, at 12,25 CEST, the corner of the dam of reservoir no.10 collapsed. The mud was released as a 1–2 m wave, flooding several nearby localities, including the village of Kolontár, ten people died, and 150 people were injured. About 40 square kilometres of land were initially affected, the spill reached the Danube on 7 October 2010. It was not initially clear how the containment at the reservoir had been breached, although the accident came after a wet summer in Hungary. Hungarian Prime Minister Viktor Orbán stated that the cause of the spill was presumably human error, the red mud involved in the accident is a waste product of the Bayer process, which refines bauxite into a form of aluminium oxide called alumina. The mud primarily contains non-aluminium compounds present in the bauxite ore, iron oxide, the compound from which the red color originates, is the main component, but it also contains other compounds. According to a release by MAL, the mud had the following chemical percentage make-up. Unlike many other mine tailings, red mud does not contain high levels of heavy metals. Analyses of the mud at Kolontár on behalf of Greenpeace showed levels of chromium 660 mg/kg, arsenic 110 mg/kg and mercury 1.2 mg/kg. The Hungarian government has stated that the mud is not poisonous, and this opinion was also supported by a paper published in the journal Science in October 2010. The wave of mud flooded streets in Kolontár, where seven people were confirmed dead, and Devecser, the cause of death of the Kolontár victims has not been formally confirmed, a spokesman for the National Directorate General for Disaster Management said that they had probably drowned. A further six people were still missing 24 hours after the accident, the NDGDM said that the high-pH mud was considered hazardous and would cause an alkaline reaction on contact if not washed off with clean water. The mayor of Devecser said that 80–90 people had taken to hospital with chemical burns. Péter Jakabos, a doctor in the hospital in Győr where many of the injured had been taken, Magyar Alumínium said that the mud was not considered to contain toxic elements according to EU standards. Initial measurements by the NDGDM showed the sludge to be extremely basic, the waste extinguished all life in the Marcal river, and reached the Danube on 7 October, prompting countries located further down the river to develop emergency plans in response. On 11 October, the Hungarian government announced that the director of MAL had been arrested. Also on the 11th, the government took control of MAL, the government planned to focus on compensation for the incident, job security, and identifying further locations at risk of accidents
30.
Marcal
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The Marcal is a right tributary of the Rába which rises near Sümeg in the Bakony region of western Hungary. The river flows north and reaches Ukk on the Little Hungarian Plain and it follows a path similar to the Rába, and in many places the two rivers are only a kilometer apart. The two rivers meet at Győr, in October 2010, the Marcal was contaminated in a chemical spill by red mud and suffered complete loss of aquatic life
31.
Danube
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The Danube is Europes second-longest river, after the Volga River, and also the longest river in the European Union region. It is located in Central and Eastern Europe, the Danube was once a long-standing frontier of the Roman Empire, and today flows through 10 countries, more than any other river in the world. Its drainage basin extends into nine more countries, the Latin name Dānuvius is one of a number of Old European river names derived from a Proto-Indo-European *dānu. Other river names from the root include the Dunajec, Dzvina/Daugava, Don, Donets, Dnieper, Dniestr. In Rigvedic Sanskrit, dānu means fluid, drop, in Avestan, in the Rigveda, Dānu once appears as the mother of Vrtra. Known to the ancient Greeks as the Istros a borrowing from a Daco-Thracian name meaning strong, in Latin, the Danube was variously known as Danubius, Danuvius or as Ister. The Dacian/Thracian name was Donaris for the upper Danube and Istros for the lower Danube, the Thraco-Phrygian name was Matoas, the bringer of luck. The Latin name is masculine, as are all its Slavic names, the German Donau is feminine, as it has been re-interpreted as containing the suffix -ouwe wetland. Classified as a waterway, it originates in the town of Donaueschingen, in the Black Forest of Germany, at the confluence of the rivers Brigach. The Danube then flows southeast for about 2,800 km, passing through four capital cities before emptying into the Black Sea via the Danube Delta in Romania and its drainage basin extends into nine more. The highest point of the basin is the summit of Piz Bernina at the Italy–Switzerland border. The land drained by the Danube extends into other countries. Many Danubian tributaries are important rivers in their own right, navigable by barges, from its source to its outlet into the Black Sea, its main tributaries are, The Danube flows through many cities, including four national capitals, more than any other river in the world. Danube remains a mountain river until Passau, with average bottom gradient 0. 0012%. Middle Section, From Devín Gate to Iron Gate, at the border of Serbia and Romania, the riverbed widens and the average bottom gradient becomes only 0. 00006%. Lower Section, From Iron Gate to Sulina, with average gradient as little as 0. 00003%, about 60 of its tributaries are also navigable. In 1994 the Danube was declared one of ten Pan-European transport corridors, routes in Central, the amount of goods transported on the Danube increased to about 100 million tons in 1987. In 1999, transport on the river was difficult by the NATO bombing of three bridges in Serbia during the Kosovo War
32.
Levee
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A levee, dike, dyke, embankment, floodbank or stopbank is an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels. It is usually earthen and often parallel to the course of a river in its floodplain or along low-lying coastlines, the word levee, from the French word levée, is used in American English. It originated in New Orleans a few years after the founding in 1718 and was later adopted by English speakers. The name derives from the trait of the ridges being raised higher than both the channel and the surrounding floodplains. The modern word dike or dyke most likely derives from the Dutch word dijk, the 126 kilometres long Westfriese Omringdijk was completed by 1250, and was formed by connecting existing older dikes. The Roman chronicler Tacitus even mentions that the rebellious Batavi pierced dikes to flood their land, the word dijk originally indicated both the trench and the bank. It is closely related to the English verb to dig, in Anglo-Saxon, the word dic already existed and was pronounced as dick in northern England and as ditch in the south. Similar to Dutch, the English origins of the lie in digging a trench. This practice has meant that the name may be given to either the excavation or the bank, thus Offas Dyke is a combined structure and Car Dyke is a trench though it once had raised banks as well. In the midlands and north of England, and in the United States, a dike is what a ditch is in the south, a property boundary marker or small drainage channel. Where it carries a stream, it may be called a dike as in Rippingale Running Dike. The Weir Dike is a dike in Bourne North Fen, near Twenty and alongside the River Glen. In the Norfolk and Suffolk Broads, a dyke may be a ditch or a narrow artificial channel off a river or broad for access or mooring, some longer dykes being named. In parts of Britain, particularly Scotland, a dyke may be a field wall, Levees can be mainly found along the sea, where dunes are not strong enough, along rivers for protection against high-floods, along lakes or along polders. Furthermore, levees have been built for the purpose of empoldering, the latter can be a controlled inundation by the military or a measure to prevent inundation of a larger area surrounded by levees. Levees have also built as field boundaries and as military defences. More on this type of levee can be found in the article on dry-stone walls, Levees can be permanent earthworks or emergency constructions built hastily in a flood emergency. When such a bank is added on top of an existing levee it is known as a cradge
33.
Cement
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A cement is a binder, a substance used in construction that sets, hardens and adheres to other materials, binding them together. Cement is seldom used solely, but is used to bind sand, Cement is used with fine aggregate to produce mortar for masonry, or with sand and gravel aggregates to produce concrete. Non-hydraulic cement will not set in wet conditions or underwater, rather, it sets as it dries and it is resistant to attack by chemicals after setting. Hydraulic cements set and become adhesive due to a reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble and so are quite durable in water and this allows setting in wet condition or underwater and further protects the hardened material from chemical attack. The chemical process for hydraulic cement found by ancient Romans used volcanic ash with added lime, the word cement can be traced back to the Roman term opus caementicium, used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were referred to as cementum, cimentum, cäment. In modern times, organic polymers are used as cements in concrete. Non-hydraulic cement, such as slaked lime, hardens by carbonation in the presence of carbon dioxide which is present in the air. The carbonation reaction requires the dry cement to be exposed to air and this whole process is called the lime cycle. Conversely, hydraulic cement hardens by hydration when water is added, Hydraulic cements are made of a mixture of silicates and oxides, the four main components being, Belite, Alite, Tricalcium aluminate, Brownmillerite. The chemistry of the above listed reactions is not completely clear and is still the object of research, Cement, chemically speaking, is a product that includes lime as the primary curing ingredient, but is far from the first material used for cementation. The Babylonians and Assyrians used bitumen to bind together burnt brick or alabaster slabs, in Egypt stone blocks were cemented together with a mortar made of sand and roughly burnt gypsum, which often contained calcium carbonate. Lime was used on Crete and by the ancient Greeks, there is evidence that the Minoans of Crete used crushed potshards as an artificial pozzolan for hydraulic cement. A kind of powder which from natural causes produces astonishing results and it is found in the neighborhood of Baiae and in the country belonging to the towns round about Mt. Vesuvius. This substance when mixed with lime and rubble not only lends strength to buildings of other kinds, the Greeks used volcanic tuff from the island of Thera as their pozzolan and the Romans used crushed volcanic ash with lime. This mixture was able to set under water increasing its resistance, the material was called pozzolana from the town of Pozzuoli, west of Naples where volcanic ash was extracted. In the absence of ash, the Romans used powdered brick or pottery as a substitute
34.
Rare-earth element
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Scandium and yttrium are considered rare earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties. They are not especially rare, but they tend to occur together in nature and are difficult to separate from one another, however, because of their geochemical properties, rare earth elements are typically dispersed and not often found concentrated as rare earth minerals in economically exploitable ore deposits. The first such mineral discovered was gadolinite, a composed of cerium, yttrium, iron, silicon. This mineral was extracted from a mine in the village of Ytterby in Sweden, a table listing the seventeen rare earth elements, their atomic number and symbol, the etymology of their names, and their main usages is provided here. The distinction between the groups is more to do with atomic volume and geological behavior, Rare earth elements became known to the world with the discovery of the black mineral Ytterbite by Lieutenant Carl Axel Arrhenius in 1787, at a quarry in the village of Ytterby, Sweden. Arrheniuss ytterbite reached Johan Gadolin, a Royal Academy of Turku professor, anders Gustav Ekeberg isolated beryllium from the gadolinite but failed to recognize other elements that the ore contained. After this discovery in 1794 a mineral from Bastnäs near Riddarhyttan, Sweden, in 1803 they obtained a white oxide and called it ceria. Martin Heinrich Klaproth independently discovered the same oxide and called it ochroia, in 1839 Carl Gustav Mosander, an assistant of Berzelius, separated ceria by heating the nitrate and dissolving the product in nitric acid. He called the oxide of the soluble salt lanthana and it took him three more years to separate the lanthana further into didymia and pure lanthana. Didymia, although not further separable by Mosanders techniques, was a mixture of oxides, in 1842 Mosander also separated the yttria into three oxides, pure yttria, terbia and erbia. The earth giving pink salts he called terbium, the one that yielded yellow peroxide he called erbium, so in 1842 the number of known rare earth elements had reached six, yttrium, cerium, lanthanum, didymium, erbium and terbium. This confusion led to false claims of new elements, such as the mosandrium of J. Lawrence Smith. There were no further discoveries for 30 years, and the element didymium was listed in the table of elements with a molecular mass of 138. In 1879 Delafontaine used the new process of optical-flame spectroscopy. Also in 1879, the new element samarium was isolated by Paul Émile Lecoq de Boisbaudran from the mineral samarskite, the samaria earth was further separated by Lecoq de Boisbaudran in 1886 and a similar result was obtained by Jean Charles Galissard de Marignac by direct isolation from samarskite. They named the element gadolinium after Johan Gadolin, and its oxide was named gadolinia, the fractional crystallization of the oxides then yielded europium in 1901. In 1839 the third source for rare earths became available and this is a mineral similar to gadolinite, uranotantalum. This mineral from Miass in the southern Ural Mountains was documented by Gustave Rose, the exact number of rare earth elements that existed was highly unclear, and a maximum number of 25 was estimated
35.
Odisha
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Odisha (/ɒˈrɪsə, ɔː-, oʊ-/, is one of the 29 states of India, located in the eastern coast. It is surrounded by the states of West Bengal to the north-east, Jharkhand to the north, Chhattisgarh to the west and north-west, Odisha has 485 kilometres of coastline along the Bay of Bengal on its east, from Balasore to Malkangiri. It is the 9th largest state by area, and the 11th largest by population and it is also the 3rd most populous state of India in terms of tribal population. Odia is the official and most widely spoken language, spoken by 33.2 million according to the 2001 Census. The ancient kingdom of Kalinga, which was invaded by the Mauryan emperor Ashoka in 261 BCE resulting in the Kalinga War, the modern state of Orissa was established on 1 April 1936, as a province in British India, and consisted predominantly of Odia-speaking regions. April 1 is celebrated as Odisha Day, the region is also known as Utkala and is mentioned in Indias national anthem, Jana Gana Mana. Cuttack was made the capital of the region by Anantavarman Chodaganga in c,1135, after which the city was used as the capital by many rulers, through the British era until 1948. Thereafter, Bhubaneswar became the capital of Odisha, the term Odisha is derived from the ancient Prakrit word Odda Visaya as in the Tirumalai inscription of Rajendra Chola I, which is dated to 1025. Sarala Das, who translated the Mahabharata into the Odia language in the 15th century, calls the region Odra Rashtra, the inscriptions of Kapilendra Deva of the Gajapati Kingdom on the walls of temples in Puri call the region Odisha or Odisha Rajya. After a brief debate, the house, Lok Sabha, passed the bill. On 24 March 2011, Rajya Sabha, the house of Parliament, also passed the bill. Prehistoric Acheulian tools dating to Lower Paleolithic era have been discovered in places in the region. Kalinga has been mentioned in ancient texts like Mahabharata, Vayu Purana, the Sabar people of Odisha have also been mentioned in the Mahabharata. Baudhayana mentions Kalinga as not yet being influenced by Vedic traditions, Ashoka of the Mauryan dynasty conquered Kalinga in the bloody Kalinga War in 261 BCE, which was the eighth year of his reign. According to his own edicts, in that war about 100,000 people were killed,150,000 were captured, the resulting bloodshed and suffering of the war is said to have deeply affected Ashoka. He turned into a pacifist and converted to Buddhism, by c.150 CE, emperor Kharavela, who was possibly a contemporary of Demetrius I of Bactria, conquered a major part of the Indian sub-continent. He also built the monastery atop the Udayagiri hill, subsequently, the region was ruled by monarchs, such as Samudragupta and Shashanka. It was also a part of Harshas empire, later, the kings of the Somavamsi dynasty began to unite the region
36.
India
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India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and it is bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. It shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the northeast, in the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives. Indias Andaman and Nicobar Islands share a border with Thailand. The Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE, in the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, early political consolidations took place under the Maurya and Gupta empires, the later peninsular Middle Kingdoms influenced cultures as far as southeast Asia. In the medieval era, Judaism, Zoroastrianism, Christianity, and Islam arrived, much of the north fell to the Delhi sultanate, the south was united under the Vijayanagara Empire. The economy expanded in the 17th century in the Mughal empire, in the mid-18th century, the subcontinent came under British East India Company rule, and in the mid-19th under British crown rule. A nationalist movement emerged in the late 19th century, which later, under Mahatma Gandhi, was noted for nonviolent resistance, in 2015, the Indian economy was the worlds seventh largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption, malnutrition, a nuclear weapons state and regional power, it has the third largest standing army in the world and ranks sixth in military expenditure among nations. India is a constitutional republic governed under a parliamentary system. It is a pluralistic, multilingual and multi-ethnic society and is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindu, the latter term stems from the Sanskrit word Sindhu, which was the historical local appellation for the Indus River. The ancient Greeks referred to the Indians as Indoi, which translates as The people of the Indus, the geographical term Bharat, which is recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations. Scholars believe it to be named after the Vedic tribe of Bharatas in the second millennium B. C. E and it is also traditionally associated with the rule of the legendary emperor Bharata. Gaṇarājya is the Sanskrit/Hindi term for republic dating back to the ancient times, hindustan is a Persian name for India dating back to the 3rd century B. C. E. It was introduced into India by the Mughals and widely used since then and its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety
37.
Scandium
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Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been classified as a rare earth element, together with yttrium. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia, Scandium is present in most of the deposits of rare earth and uranium compounds, but it is extracted from these ores in only a few mines worldwide. Because of the low availability and the difficulties in the preparation of metallic scandium, the positive effects of scandium on aluminium alloys were discovered in the 1970s, and its use in such alloys remains its only major application. The global trade of scandium oxide is about 10 tonnes per year, the properties of scandium compounds are intermediate between those of aluminium and yttrium. A diagonal relationship exists between the behavior of magnesium and scandium, just as there is between beryllium and aluminium, in the chemical compounds of the elements in group 3, the predominant oxidation state is +3. Scandium is a metal with a silvery appearance. It develops a slightly yellowish or pinkish cast when oxidized by air and it is susceptible to weathering and dissolves slowly in most dilute acids. It does not react with a 1,1 mixture of acid and 48% hydrofluoric acid. Scandium turnings ignite in air with a brilliant yellow flame to form scandium oxide, in nature, scandium is found exclusively as the isotope 45Sc, which has a nuclear spin of 7/2. Thirteen radioisotopes have been characterized with the most stable being 46Sc, which has a half-life of 83.8 days, 47Sc,3.35 days, the positron emitter 44Sc,4 h, and 48Sc,43.7 hours. All of the radioactive isotopes have half-lives less than 4 hours. This element also has five meta states, with the most stable being 44mSc, the isotopes of scandium range from 36Sc to 60Sc. The primary decay mode at masses lower than the stable isotope, 45Sc, is electron capture. The primary decay products at atomic weights below 45Sc are calcium isotopes, in Earths crust, scandium is not rare. Estimates vary from 18 to 25 ppm, which is comparable to the abundance of cobalt, Scandium is only the 50th most common element on Earth, but it is the 23rd most common element in the Sun. However, scandium is distributed sparsely and occurs in trace amounts in many minerals, rare minerals from Scandinavia and Madagascar such as thortveitite, euxenite, and gadolinite are the only known concentrated sources of this element. Thortveitite can contain up to 45% of scandium in the form of scandium oxide, the stable form of scandium is created in supernovas via the r-process
38.
Chemical waste
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Chemical waste is a waste that is made from harmful chemicals. Chemical waste may fall under such as COSHH in the United Kingdom, or the Clean Water Act and Resource Conservation. In the U. S. the Environmental Protection Agency and the Occupational Safety and Health Administration, as well as state and local regulations also regulate chemical use, Chemical waste may or may not be classed as hazardous waste. A chemical hazardous waste is a solid, liquid, or gaseous material that displays either a “Hazardous Characteristic” or is specifically “listed” by name as a hazardous waste, there are four characteristics chemical wastes may have to be considered as hazardous. These are Ignitability, Corrosivity, Reactivity, and Toxicity and this type of hazardous waste must be categorized as to its identity, constituents, and hazards so that it may be safely handled and managed. Chemical waste is a term and encompasses many types of materials. Consult the Material Safety Data Sheet, Product Data Sheet or Label for a list of constituents and these sources should state whether this chemical waste is a waste that needs special disposal. Innocuous aqueous waste may be poured down the sink, some chemicals are washed down with excess water. This includes, concentrated and dilute acids and alkalis, harmless soluble inorganic salts, alcohols containing salts, hypochlorite solutions, fine silica, aqueous waste containing toxic compounds are collected separately. Waste elemental mercury, spent acids and bases may be collected separately for recycling, waste organic solvents are separated into chlorinated and non-chlorinated solvent waste. Chlorinated solvent waste is incinerated at high temperature to minimize the formation of dioxins. Non-chlorinated solvent waste can be burned for energy recovery, in contrast to this, chemical materials on the Red List should never be washed down a drain. Moreover, the Environmental Protection Agency prohibits disposing certain materials down any UVM drain, broken glassware are usually collected in plastic-lined cardboard boxes for landfilling. Due to contamination, they are not suitable for recycling. Similarly, used hypodermic needles are collected as sharps and are incinerated as medical waste, many chemicals may react adversely when combined. It is recommended that incompatible chemicals be stored in areas of the lab. Acids should be separated from alkalis, metals, cyanides, sulfides, azides, phosphides, the reason being, when combined acids with these type of compounds, violent exothermic reaction can occur possibly causing flammable gas, and in some cases explosions. Oxidizers should be separated from acids, organic materials, metals, reducing agents and this is because when combined oxidizers with these type of compounds, inflammable, and sometimes toxic compounds can occur
39.
Flash flood
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A flash flood is a rapid flooding of geomorphic low-lying areas, washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a thunderstorm, hurricane, tropical storm. Flash floods may occur after the collapse of an ice or debris dam, or a human structure such as a man-made dam. Flash floods are distinguished from regular floods by a timescale of less than six hours, the water that is temporarily available is often used by foliage with rapid germination and short growth cycles, and by specially adapted animal life. Flash floods can occur under several types of conditions, Flash flooding occurs when it rains rapidly on saturated soil or dry soil that has poor absorption ability. The runoff collects in gullies and streams and, as they join to form larger volumes, often forms a fast flowing front of water, in areas on or near volcanoes, flash floods have also occurred after eruptions, when glaciers have been melted by the intense heat. Flash floods are known to occur in the highest mountain ranges of the United States and are common in the arid plains of the Southwestern United States. Flash flooding can also be caused by extensive rainfall released by hurricanes and other tropical storms, human activities can also cause flash floods to occur. When dams fail, a quantity of water can be released. Many people tend to underestimate the dangers of flash floods, what makes flash floods most dangerous is their sudden nature and fast-moving water. A vehicle provides little to no protection against being swept away, it may make people overconfident, more than half of the fatalities attributed to flash floods are people swept away in vehicles when trying to cross flooded intersections. As little as 2 feet of water is enough to carry away most SUV-sized vehicles. The U. S. National Weather Service reported in 2005 that, using a national 30-year average, more people die yearly in floods,127 on average, than by lightning, tornadoes, in deserts, flash floods can be particularly deadly for several reasons. First, storms in arid regions are infrequent, but they can deliver an enormous amount of water in a short time. Second, these rains often fall on poorly absorbent and often clay-like soil, in fact, in some areas, desert roads frequently cross dry river and creek beds without bridges. From the drivers perspective, there may be clear weather, when a river unexpectedly forms ahead of or around the vehicle in a matter of seconds. Finally, the lack of rain to clear water channels may cause flash floods in deserts to be headed by large amounts of debris, such as rocks, branches. 1889, Johnstown Flood, Pennsylvania, U. S. more than 2,200 people dead 1903, Heppner Flood of 1903, Oregon, United States,247 dead, 25% of the city 1938, Los Angeles Flood of 1938, California, U. S. S
