Azurite, flotation

Azurite (Cu3(0H2)(C02)2, Cu 55.3%, SG = 3.7) usually appears in small quantities together with malachite in a number of deposits in Zambia and Congo. From plant and laboratory data, azurite has similar flotation properties as malachite. 

In most industrial processes, copper is produced from the ore chalcopyrite, a mixed copper-iron sulfide mineral, or from the carbonate ores azurite and malachite. The extraction process depends on the chemical compositions of the ore. The ore is crushed and copper is separated by flotation. It then is roasted at high temperatures to remove volatile impurities. In air, chalcopyrite is oxidized to iron(ll) oxide and copper(ll) oxide ... 

Ores of copper native copper, cuprite, chalcocite, chalcopyrite, malachite, azurite. Metallurgy of ores containing native copper, oxide and carbonate ores, sulfide ores. Gangue, flux, flotation, roasting of ores, matte, blister copper. Cupric compounds copper sulfate (blue vitriol, bluestone), Bordeaux mixture, cupric chloride, cupric bromide, cupric hydroxide. Test for cupric ion with Fehling s solution. Cuprous compounds cuprous chloride, cuprous bromide, cuprous iodide, cuprous oxide. Covalent-bond structure of cuprous compounds. 

The two main classes of copper ores are the mixed sulfides of copper and iron—such as chalcopyrite, CuFeS2—and the basic carbonates, such as azurite, Cu3(C03)2(0H)2, and malachite, Cu2C03(0H)2. Let s consider CuFeS2 (or CuS-FeS). The copper compound is separated from gangue by flotation (Figures 22-2b and 22-11) and then roasted to remove volatile impurities. Enough air is used to convert iron(II) sulfide, but not copper(n) sulfide, to the oxide. 

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