Roasting reactions 677 +2 oxidation state

This element occurs in nature in the uncombined state as native copper and in the combined state as various oxides, sulfides, and carbonates. The chief mineral is chalcopyrite, CuFeS2, from which the element is extracted by roasting (heating in air) followed by reduction. The roasting reaction can be written... 

The production of copper from sulphide minerals is accomplished with a preliminary partial roast of die sulphides before reaction widr air in the liquid state, known as mattes, to form copper metal (conversion). The principal sources of copper are minerals such as chalcopyrite, CuFeSa and bornite CuaFeSa, and hence the conversion process must accomplish the preferential oxidation of non, in the form of FeO, before the copper metal appears. As mentioned before, tire FeO-SiOa liquid system is practically Raoultian, and so it is relatively easy to calculate the amount of iron oxidation which can be canned out to form this liquid slag as a function of the FeO/SiOa ratio before copper oxidation occurs. The liquid slag has a maximum mole fraction of FeO at the matte blowing temperatures of about 0.3, at solid silica saturation. 

Solid state reactant Thermal decompositions of a solid Oxidation or reduction of a solid Precipitation Solution heating or cooling Evaporative salting-out Chemical reaction with insoluble product Hydrothermal synthesis Forced insolubility Dissolution reprecipitation Evaporative Condensation Gas phase reaction with solid product Thermal decompositions Oxidation or reduction reactions Combination reactions with a solid product Solvent removal Spray drying Freeze drying Spray roasting Sol-gel synthesis Melt solidification... 

The Metallurgy of Lead. The principal ore of lead is galena, PbS, which occurs, often in beautiful cubic crystals, in large deposits in the United States, Spain, and Mexico. The ore is first roasted until part of it has been converted into lead oxide, PbO, and lead sulfate, PbS04. The supply of air to the furnace is then cut off, and the temperature is raised. Metallic lead is then produced by the reactions... 

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