Pyrites copper

Pyrex glass Pyrites (copper) Pyrites (iron) Pyroxylin plastics Quartz... 

Selenium was isolated some 35 y after tellurium and, since the new element resembled tellurium, it was named from the Greek askrivr], selene, the moon. The discovery was made in 1817 by the Swedish chemist J. J. Berzelius (discoverer of Si, Ce and Th) and J. G. Gahn (discoverer of Mn) they observed a reddish-brown deposit during the burning of sulfur obtained from Fahlun copper pyrites, and showed it to be volatile and readily reducible to the new element. 

Kupferkies, m. copper pyrites (chalcopyrite). — bunter —, bornite. 

Chalcopyrite or copper pyrite, CuFeS2, is one of the major ores of copper, estimated to account for about 50% of all the element s deposits. Compounds of the chalcopyrite type of the general formula ABC2 (with A = Cu, Ag B = Al, Ga, In ... 

A large dump of copper pyrites ore ignited after heavy rain. The thick layer (6-7 m) and absence of ventilation were contributory factors to the accelerating aerobic oxidation which finally led to ignition. 

During preparations for blasting the sulfide mineral copper pyrites, ammonium nitrate-based blasting cartridges exploded prematurely in the blast holes. This was attributed to exothermic interaction of acid ground-water with the sulfide-oxidant combination. 

It is found in most countries of the world, but only a few high-grade deposits are cost-effective to mine. Examples of some of its ores are cuprite (CuO ), tenorite (CuO), malachite [CuCOj Cu(OH)2], chalcocite (Cu S), covellite (CuS), bornite (CugFeS ), and chalcopyrite, also known as copper pyrite. 

Oompeot brown iron ore, 192. Omnpounds ofiton, 192. Copper pyrites, 194. Coouimbite, 104. 

Evolved in the roasting of copper pyrites and other sul> phureous ores. 

MINEEALS OF TIN.—Tin is found almost invariably in the form of biDoxido of tin or tin-stone, and in some instances associated with iron and copper pyrites, forming what is called tin pyrites or bell-metal ore, but the quantity so existing is very small. 

Pyrites is described by Dioscorides as a land of stone from which copper is made. It resembles brass in color, and strikes sparks easily. There is no evidence that any discrimination was made by Dioscorides between iron and copper pyrites. 

Iron is obtained from misy, a yellow, gold-appearing, hard stone (pyrites ). Pliny vaguely describes under the same name a product formed by roasting a copper ore. According to Berthelot, the misy of Pliny is the product of a gentle oxidation of copper pyrites, a mixture of basic sulphates of iron and copper.48... 

Cadmia, it will be remembered, is the impure zinc oxide, containing sometimes lead and copper oxides, from the furnaces in which brass was smelted. Misy was the partly oxidized iron or copper pyrites, essentially basic sulphates of iron and copper. Synopian red was haematite. This mixture, assuming the reducing action of the fuel in the furnace, or of any other reducing agent not specified in the recipe would yield an alloy of gold and zinc, with some copper and perhaps some lead. 

It will be recalled that the chalcanthum of Pliny and Dioscorides was either blue vitriol, green vitriol or apparently more commonly a mixture of the two, obtained by the weathering of wet iron or copper-pyrites. The above specifications would appear to recognize these varieties of flowers of copper. Some specimen recipes will perhaps convey a more adequate understanding of the processes employed. 

The name marcliasita was generally applied to metallic sulphides such as iron and copper pyrites, and other sulphides of metallic luster, though taken by itself the above description gives little basis for such identification. 

In Cornwall and Devon the ores used contain arsenopyrite mixed with iron and copper pyrites, tin ore, zinc blende, galena, etc. Before roasting, the ores are separated as far as possible by hand, and tinstone is removed by washing the finely powdered material. The roasting is conducted in a reverberatory furnace having a revolving floor over which a number of scrapers are fixed. The ore, which contains 10 to 80 per cent. As, is introduced through a hopper on to the floor, which revolves once every 12 minutes or so. It is heated to dull redness for... 

Targe lumps of the ore are first crushed and ground up by very heavy machinery. Some ores are already fairly concentrated when mined. For example, in some parts of the world, haematite contains over 80% Fe2Os. However, other ores, such as copper pyrites, are often found to be less concentrated, with only 1% or less of the copper compound, and so they have to be concentrated before the metal can be extracted. The method used to extract the metal from its ore depends on the position of the metal in the reactivity series. 

Copper Copper pyrites Copper iron sulfide CuFeSj The sulfide ore is roasted in air... 

Sulfur is found in large quantities but in various forms throughout the world. It is found in metal ores such as copper pyrites or chalcopyrite (CuFeS2) and zinc blende (ZnS) and in volcanic regions of the world. Natural gas and oil contain sulfur and its compounds, but the majority of this sulfur is removed as it would cause environmental problems. Sulfur obtained from these sources is known as recovered sulfur and it is an important source of the element. It is also found as elemental sulfur in sulfur beds in Poland, Russia and the US (Louisiana). These sulfur beds are typically 200 m below the ground. Sulfur from these beds is extracted using the Frasch process, named after its inventor Hermann Frasch. 

---