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Electrochemistry of the Oxidative Leaching of Copper from Chalcopyrite

AJ. Parker

出版	Mintek, 1981
URL	http://books.google.com.hk/books?id=qrhcjwEACAAJ&hl=&source=gbs_api

註釋

Electrochemical aspects of semi-conductors explain many features of chalcopyrite leaching by iron (III) and copper (II) salts. A surface film thought to be a metal deficient polysulphide, which is a semi- conductor, forms on chalcopyrite during oxidation. This film is thermally unstable and slows transport of ions, slows electron transfer to oxidants and slows the supply of holes to the solid-solution interface. The Fe(3+)/Fe(2+) couple, indeed most redox couples, are much less reversible on corroding chalcopyrite than on pyrite. On corroding chalcopyrite Fe(3+)/Fe(2+) is much less reversible than are Cu(2+)/Cu(+), I3( - )/I( - ) and Fe(CN)6(3- )/Fe(CN)6(4- ) salts. The sulphur film which forms on corroding chalcopyrite does not account for the electrochemical or kinetic aspects of chalcopyrite leaching. Catalysis of FeCl3 leaching by CuCl2 in solution, or by Ag2S or FeS2 in the solid CuFe2, is explained by the electrochemical model. Ways of enhancing the rates of leaching are suggested. (AUAB).