LEACHABILITY OF MECHANOCHEMICALLY PRETREATED CHALCOPYRITE

This paper is concerned with possibility of chalcopyrite CuFeS2 activa tion resulting in acceleration of its leaching with ferric sulphate. M echanical activation of CuFeS2 produced by grinding in a planetary mil l brings about an increase in its specific surface area as well as dis ordering of its structure. nle recovery achieved by leaching rises 2.7 - 7.7 times when compared with non-activated ''as-received'' sample. Activation of the mineral can also be accomplished by intensive grindi ng in the presence of copper, iron and sulphur. In this case, leaching lasting 60 minutes gives more than 20-fold increase in recovery of co pper in leaching liquor. Among the products of mechanochemical reactio ns of CuFeS2, the substances CuS, Cu5FeS4, Cu17.6Fe17.7S32 and Cu7S4 c all unambiguously be identified whereas the identification of Fe3S4, C u8Fe8S16 and Cu2S is less certain.