Smelting, copper pyritic

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. 

After lixiviation of the sulphate, oxide, or chlorides obtained by these methods, the copper is precipitated by the process already described. If the cement copper thus obtained contains over 55 per cent, of the metal, it is refined directly, if the percentage is lower, it is first smelted with matte or calcined copper pyrites. 

Most metals, with the exception of some precious ones, are found in the form of minerals or ores. The ores are smelted to convert them into metals e.g. iron is obtained from iron ore (haematite), aluminium from bauxite and copper from copper pyrites. 

The principal direct raw materials used to make sulfuric acid are elemental sulfur, spent (contaminated and diluted) sulfuric acid, and hydrogen sulfide. Elemental sulfur is by far the most widely used. In the past, iron pyrites or related compounds were often used but as of the mid-1990s this type of raw material is not common except in southern Africa, China, Ka2akhstan, Spain, Russia, and Ukraine (96). A large amount of sulfuric acid is also produced as a by-product of nonferrous metal smelting, ie, roasting sulfide ores of copper, lead, molybdenum, nickel, 2inc, or others. 

Orkla A complex process for recovering sulfur from pyrite. The ore was smelted with coke, limestone, and quartz, with very little air at 1,600°C, and the iron was removed as a slag. The copper and other nonferrous metals formed a matte with the sulfur. Pyrolysis of this matte removed half of the sulfur. An air blast removed the other half without oxidizing it. Developed by the Orkla Mining Company, Norway, between 1919 and 1927. First commercialized at Thamshavn, Norway, in 1931, but the plant closed in 1962. The process was used for many years in Spain, Portugal, and Hungary. 

The practical application of the pyritic smelting principle to suitable raw ores, and to practically all copper mattes. 

Thallium is manufactured commercially as a by-product from the roasting of pyrite ores, from sulfuric acid plants, and from the smelting of lead, zinc, and copper. The global... 

Silver-coloured Pyrites, the White or Water Pyrites, or Gravel of the Metallurgists. Silver is smelted from it. Pliny mentions it, if I mistake not, but, like all the ancients, is ignorant of its argentiferous character. Copper is also smelted from it, as Serapion testifies of Marcasite. Dioscorides also plainly states this fact concerning Pyrites. Silver-coloured Pyrites sometimes contains Silver only, sometimes Copper only, sometimes both, and again it may contain Silver and Black Lead, or several metals. Occasionally it is barren. I consider that it usually has more Silver than any other substance. 

A method of smelting pyritic copper, silver, or gold ores by the heat- of oxidation of the pyrites, without the aid of any other fuel was introduced as recently as 1905 in actual practice, however, up to 5 per cent, of carbonaceous fuel is now added. Water-jacketed blast furnaces are used, and air—pre-heated in some cases—is liberally supplied through a large number of tuyeres. 

Other Processes.—(a) At the Stephan Works, in Upper Hungary, antimony is extracted from the spiess, which has been desilverised by amalgamation. The spiess is obtained from the smelting of fahl-ores. The antimony is extracted by using pyritic ores in a shaft furnace. The copper is thereby converted into sulphide by the sulphur of the pyrites, and the impure antimony obtained is refined. 

---