Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in paper recycling and waste-water treatment industries; this was first used in the mining industry, where it was one of the great enabling technologies of the 20th century. It has been described as "the single most important operation used for the recovery and upgrading of sulfide ores"; the development of froth flotation has improved the recovery of valuable minerals, such as copper- and lead-bearing minerals. Along with mechanized mining, it has allowed the economic recovery of valuable metals from much lower grade ore than previously. Descriptions of the use of a flotation process have been found in ancient Greek and Persian literature suggesting its antiquity. During the late nineteenth century, the process basics were discovered through a slow evolutionary phase. During the early twentieth century, it revolutionized mineral processing around the globe. Occurring chemicals such as fatty acids and oils were used as flotation reagents in a large quantity to increase the hydrophobicity of the valuable minerals.
Since the process has been adapted and applied to a wide variety of materials to be separated, additional collector agents, including surfactants and synthetic compounds have been adopted for various applications. Englishman William Haynes patented a process in 1860 for separating sulfide and gangue minerals using oil. Writers have pointed to Haynes's as the first "bulk oil flotation" patent, though there is no evidence of its being field tested, let alone used commercially. While in 1877 the brothers Bessel of Dresden, introduced their commercially successful oil and froth flotation process for extracting graphite, considered by some the root of froth flotation. However, because the Bessel process was used on graphite not gold, copper, zinc, their work has been ignored by most historians of the technology. Seventy-seven year old inventor Hezekiah Bradford of Philadelphia invented a "method of saving floating material in ore-separation” and received U. S. patent No. 345951 on July 20, 1886.
He had received his first patent in 1834 invented machinery to separate slate from coal during the 1850s-1860s, invented the Bradford Breaker, still in use by the coal industry today. His "Bradford Ore Separator," patented 1853 and improved over the decades, was used to concentrate iron and lead-zinc ores by specific gravity, but lost some of the metal as float off the concentration process; the 1886 patent was to capture this "float" using surface tension, the first of the skin-flotation process patents, eclipsed by oil froth flotation. It is uncertain if his 1886 patented "flotation" process was introduced. On August 24, 1886, Carrie Everson received a patent for her process calling for oil but an acid or a salt, a significant step in the evolution of the process history. By 1890, tests of the Everson process had been made at Georgetown and Silver Cliff and Baker, Oregon, she abandoned the work with the death of her husband, before perfecting a commercial successful process. During the height of legal disputes over the validity or not of various patents during the 1910s, Everson's was pointed to as the initial flotation patent -- which would have meant that the process was not patentable again by contestants.
Much confusion has been clarified by historian Dawn Bunyak. The recognized first successful commercial flotation process for mineral sulphides was invented by Frank Elmore who worked on the development with his brother, Stanley; the Glasdir copper mine at Llanelltyd, near Dolgellau in North Wales was bought in 1896 by the Elmore brothers in conjunction with their father, William. In 1897, the Elmore brothers installed the world's first industrial size commercial flotation process for mineral beneficiation at the Glasdir mine; the process was not froth flotation but used oil to agglomerate pulverised sulphides and buoy them to the surface, was patented in 1898. The operation and process was described in the April 25, 1900 Transactions of the Institution of Mining and Metallurgy of England, reprinted with comment, June 23, 1900, in the Engineering and Mining Journal, New York City. By this time they had recognized the importance of air bubbles in assisting the oil to carry away the mineral particles.
As modifications were made to improve the process, it became a success with base metal ores from Norway to Australia. The Elmores had formed a company known as the Ore Concentration Syndicate Ltd to promote the commercial use of the process worldwide. In 1900, Charles Butters of Berkeley, acquired American rights to the Elmore process after seeing a demonstration at Llanelltyd, Wales. Butters, an expert on the cyanide process, built an Elmore process plant in the basement of the Dooley Building, Salt Lake City, tested the oil process on gold ores throughout the region and tested the tailings of the Mammoth gold mill, Tintic district, but without success; because of Butters’ reputation and the news of his failure, as well as the unsuccessful attempt at the LeRoi gold mine at Rossland, B. C. the Elmore process was all but ignored in North America. Developments elsewhere in Broken Hill, Australia by Minerals Separation, led to decades of hard fought legal battles and litigations for the Elm
Potrerillos is a ghost town in the interior of Atacama Region, Chile. Potrerillos became established as mining camp in the 1920s by Andes Copper Mining Company. One of Chile's Gran Mineria, the copper porphyry mine was identified and developed by William Burford Braden; the mine was active from 1927 until 1959. Located 12 km east of the Sierra del Castillo fault, the area consists of Jurassic to Lower Cretaceous marine and volcanic host rocks. During the Late Eocene, the Porfido Cobre intrusion induced Cu-Mo mineralization; the supergene oxidation zone "is dominated by malachite and azurite in and around the Porfido Cobre stock." El Salvador mine Chuquicamata El Teniente El Salvador mine Los Pelambres mine Chanarcillo Escondida
Porphyry copper deposit
Porphyry copper deposits are copper orebodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name. In stages, circulating meteoric fluids may interact with the magmatic fluids. Successive envelopes of hydrothermal alteration enclose a core of disseminated ore minerals in stockwork-forming hairline fractures and veins; because of their large volume, porphyry orebodies can be economic from copper concentrations as low as 0.15% copper and can have economic amounts of by-products such as molybdenum and gold. In some mines, those metals are the main product; the first mining of low-grade copper porphyry deposits from large open pits coincided with the introduction of steam shovels, the construction of railroads, a surge in market demand near the start of the 20th century. Some mines exploit porphyry deposits that contain sufficient gold or molybdenum, but little or no copper.
Porphyry copper deposits are the largest source of copper ore. Most of the known porphyrys are concentrated in: western South and North America and Southeast Asia and Oceania - along the Pacific Ring of Fire. Only a few are identified in Namibia and Zambia; the greatest concentration of the largest copper porphyrys is in northern Chile. All mines exploiting large porphyry deposits produce from open pits. Porphyry copper deposits represent an important resource and the dominant source of copper, mined today to satisfy global demand. Via compilation of geological data, it has been found that the majority of porphyry deposits are Phanerozoic in age and were emplaced at depths of 1 to 6 kilometres with vertical thicknesses on average of 2 kilometres. Throughout the Phanerozoic an estimated 125,895 porphyry copper deposits were formed. Thus, 38 % remain in the crust, it is estimated that the Earth’s porphyry copper deposits contain 1.7×1011 tonnes of copper. Porphyry deposits represent an important resource of copper.
In general, porphyry deposits are characterized by low grades of ore mineralization, a porphyritic intrusive complex, surrounded by a vein stockwork and hydrothermal breccias. Porphyry deposits are associated with subduction zone magmas. Porphyry deposits are clustered in discrete mineral provinces, which implies that there is some form of geodynamic control or crustal influence affecting the location of porphyry formation. Porphyry deposits tend to occur in orogen-parallel belts. There appears to be discrete time periods in which porphyry deposit formation appears to be concentrated or preferred. For copper-molybdenum porphyry deposits, formation is broadly concentrated in three time periods: Palaeocene-Eocene, Eocene-Oligocene, middle Miocene-Pliocene. For both porphyry and epithermal gold deposits, they are from the time period ranging from the middle Miocene to the Recent period; however notable exceptions are known. Most large-scale porphyry deposits have an age of less than 20 million years.
However there are notable exceptions, such as the 438 million year old Cadia-Ridgeway deposit in New South Wales. This young age reflects the preservation potential of this type of deposit, it may be however, that the skewed distribution towards most deposits being less than 20 million years is at least an artifact of exploration methodology and model assumptions, as large examples are known in areas which were left only or under-explored due to their perceived older host rock ages, but which were later found to contain large, world class examples of much older porphyry copper deposits. In general, the majority of large porphyry deposits are associated with calc-alkaline intrusions, although some of the largest gold-rich deposits are associated with high-K calc-alkaline magma compositions. Numerous world-class porphyry copper-gold deposits are hosted by high-K or shoshonitic intrusions, such as Bingham copper-gold mine in USA, Grasberg copper-gold mine in Indonesia, Northparkes copper-gold mine in Australia, Oyu Tolgoi copper-gold mine in Mongolia and Peschanka copper-gold prospect in Russia.
The magmas responsible for porphyry formation are conventionally thought to be generated by the partial melting of the upper part of post-subduction, stalled slabs that are altered by seawater. Shallow subduction of young, buoyant slabs can result in the production of adakitic lavas via partial melting. Alternatively, metasomatised mantle wedges can produce oxidized conditions that results in sulfide minerals releasing ore minerals, which are able to be transported to upper crustal levels. Mantle melting can be induced by transitions from convergent to transform margins, as well as the steepening and trenchward retreat of the subducted slab. However, the latest belief is that dehydration that occurs at the blueschist-eclogite transition affects most subducted slabs, rather than partial melting. After dehydration, solute
Bornite known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system. Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places, its striking iridescence gives it peacock ore. Bornite is an important copper ore mineral and occurs in porphyry copper deposits along with the more common chalcopyrite. Chalcopyrite and bornite are both replaced by chalcocite and covellite in the supergene enrichment zone of copper deposits. Bornite is found as disseminations in mafic igneous rocks, in contact metamorphic skarn deposits, in pegmatites and in sedimentary cupriferous shales, it is important as an ore for its copper content of about 63 percent by mass. At temperatures above 228 °C, the structure is isometric with a unit cell, about 5.50 Å on an edge. This structure is based on cubic close-packed sulfur atoms, with copper and iron atoms randomly distributed into six of the eight tetrahedral sites located in the octants of the cube.
With cooling, the Fe and Cu become ordered, so that 5.5 Å subcells in which all eight tetrahedral sites are filled alternate with subcells in which only four of the tetrahedral sites are filled. Substantial variation in the relative amounts of copper and iron is possible and solid solution extends towards chalcopyrite and digenite. Exsolution of blebs and lamellae of chalcopyrite and chalcocite is common. Rare crystals are cubic, dodecahedral, or octahedral. Massive. Penetration twinning on the crystallographic direction, it occurs globally in copper ores with notable crystal localities in Butte, Montana and at Bristol, Connecticut in the U. S, it is collected from the Carn Brea mine and elsewhere in Cornwall, England. Large crystals are found from Austria. There are traces of it found amongst the hematite in the Pilbara region of Western Australia, it was first described in 1725 for an occurrence in the Krušné Horny Mountains, Karlovy Vary Region, Bohemia in what is now the Czech Republic. It was named in 1845 for Austrian mineralogist Ignaz von Born.
Cuprite Tennantite Tetrahedrite List of minerals named after people Notes BibliographyPalache, C. H. Berman, C. Frondel Dana’s system of mineralogy, v. I, 195–197. Manning, P. G. A study of the bonding Properties of Sulphur in Bornite, The Canadian Mineralogist, 9, 85-94
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula CuFeS2, it has a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black. On exposure to air, chalcopyrite oxidises to a variety of oxides and sulfates. Associated copper minerals include the sulfides bornite, covellite, digenite. Chalcopyrite is found in association with native copper. Natural chalcopyrite has no solid solution series with any other sulfide minerals. There is limited substitution of Zn with Cu despite chalcopyrite having the same crystal structure as sphalerite. Minor amounts of elements such as Ag, Au, Cd, Co, Ni, Pb, Sn, Zn can be measured substituting for Cu and Fe. Selenium, Bi, Te, As may substitute for sulfur in minor amounts. Chalcopyrite is present with many ore-bearing environments via a variety of ore forming processes. Chalcopyrite is present in volcanogenic massive sulfide ore deposits and sedimentary exhalative deposits, formed by deposition of copper during hydrothermal circulation.
Chalcopyrite is concentrated in this environment via fluid transport. Porphyry copper ore deposits are formed by concentration of copper within a granite stock during the ascent and crystallisation of a magma. Chalcopyrite in this environment is produced by concentration within a magmatic system. Chalcopyrite is an accessory mineral in Kambalda type komatiitic nickel ore deposits, formed from an immiscible sulfide liquid in sulfide-saturated ultramafic lavas. In this environment chalcopyrite is formed by a sulfide liquid stripping copper from an immiscible silicate liquid. Chalcopyrite is the most important copper ore. Chalcopyrite ore occurs in a variety of ore types, from huge masses as at Timmins, Ontario, to irregular veins and disseminations associated with granitic to dioritic intrusives as in the porphyry copper deposits of Broken Hill, the American cordillera and the Andes; the largest deposit of nearly pure chalcopyrite discovered in Canada was at the southern end of the Temagami Greenstone Belt where Copperfields Mine extracted the high-grade copper.
Chalcopyrite is present in the supergiant Olympic Dam Cu-Au-U deposit in South Australia. Chalcopyrite may be found in coal seams associated with pyrite nodules, as disseminations in carbonate sedimentary rocks. Crystallographically the structure of chalcopyrite is related to that of zinc blende ZnS; the unit cell is twice as large, reflecting an alternation of Cu+ and Fe3+ ions replacing Zn2+ ions in adjacent cells. In contrast to the pyrite structure chalcopyrite has single S2− sulfide anions rather than disulfide pairs. Another difference is. Copper metal can be extracted from the roasting of chalcopyrite, as shown in the following reaction: 2CuFeS2 + 5O2 + 2SiO2 ⇌ 2Cu + 4SO2 + 2FeSiO3 Although if roasted it produces Cu2S and FeO. Classification of minerals List of minerals Kesterite
Escondida is Jolie Holland's second album and first studio album. It was released in 2004. "Escondida" means "hidden" in Portuguese. All tracks written by Jolie Holland except. "Sascha" – 3:08 "Black Stars" – 4:54 "Old Fashioned Morphine" – 4:35 "Amen" – 3:32 "Mad Tom of Bedlam" – 2:52 "Poor Girl's Blues" – 5:26 "Goodbye California" – 3:28 "Do You?" – 4:49 "Darlin Ukelele" - 4:07 "Damn Shame" – 4:49 "Tiny Idyll/Lil Missy" – 2:41 "Faded Coat of Blue" – 3:47 Jolie Holland – voice, piano, ukulele Dave Mihaly – drums, voice Brian Miller – electric guitar, acoustic guitar, voice Keith Cary – double bass, banjo Ara Anderson – trumpet Enzo Garcia – musical saw Paul Scriver – soprano saxophone
In ore deposit geology, supergene processes or enrichment are those that occur near the surface as opposed to deep hypogene processes. Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering; the descending meteoric waters oxidize the primary sulfide ore minerals and redistribute the metallic ore elements. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, react with hypogene sulfides at the supergene-hypogene boundary; the reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is noted in copper ore deposits where the copper sulfide minerals chalcocite Cu2S, covellite CuS, digenite Cu1.8S, djurleite Cu31S16 are deposited by the descending surface waters. All such processes take place at atmospheric conditions, 25 °C and atmospheric pressure. Different zones can be identified at different depths.
From the surface down they are gossan cap, leached zone, oxidized zone, water table, enriched zone and primary zone. Pyrite FeS2 is abundant, near the surface it oxidises to insoluble compounds such as goethite FeO and limonite, forming a porous covering to the oxidized zone known as gossan or iron hat. Prospectors take gossan as an indication; the groundwater contains dissolved oxygen and carbon dioxide, as it travels downwards it leaches out the minerals in the rocks to form sulfuric acid, other solutions that continue moving downwards. Above the water table the environment is oxidizing, below it is reducing. Solutions travelling downward from the leached zone react with other primary minerals in the oxidised zone to form secondary minerals such as sulfates and carbonates, limonite, a characteristic product in all oxidised zones. In the formation of secondary carbonates, primary sulfide minerals are first converted to sulfates, which in turn react with primary carbonates such as calcite CaCO3, dolomite CaMg2 or aragonite to produce secondary carbonates.
Soluble salts continue on down, but insoluble salts are left behind in the oxidised zone where they form. An example is the lead mineral anglesite PbSO4. Copper may be precipitated as malachite Cu22 or azurite Cu322. Malachite, cuprite Cu2O, pyromorphite Pb53Cl and smithsonite ZnCO3 are stable in oxidising conditions and they are characteristic of the oxidation zone. At the water table the environment changes from an oxidizing environment to a reducing one. Copper ions that move down into this reducing environment form a zone of supergene sulfide enrichment. Covellite CuS, chalcocite Cu2S and native copper Cu are stable in these conditions and they are characteristic of the enriched zone; the net effect of these supergene processes is to move metal ions from the leached zone to the enriched zone, increasing the concentration there to levels higher than in the unmodified primary zone producing a deposit worth mining. The primary zone contains unaltered primary minerals. Chalcopyrite CuFeS2 alters to the secondary minerals bornite Cu5FeS4, covellite CuS and brochantite Cu4SO46.
Galena PbS alters to secondary anglesite PbSO4 and cerussite PbCO3. Sphalerite ZnS alters to secondary hemimorphite Zn4Si2O72. H2O, smithsonite ZnCO3 and manganese-bearing willemite Zn2SiO4. Pyrite FeS2 alters to secondary melanterite FeSO4.7H2O. If the original deposits contain arsenic and phosphorus bearing minerals secondary arsenates and phosphates will be formed. Hypogene