REACTIVITY OF MECHANICALLY ACTIVATED CHALCOPYRITE

Mechanical activation by grinding is a complex process involving alter ation of structure, chemical composition and properties of solid subst ances, In this article the characteristic features of mechanically ind uced changes in minerals with close packed anion sublattice are illust rated on the example of planetary and vibration ground chalcopyrite. S ummarizing the results of a longlasting research involving data obtain ed by Mossbauer spectroscopy, ESR, XPS, XRD and measuring of magnetic susceptibility, the changes in surface composition are characterised a nd a critical structure favourable loosening for a magnetic order-diso rder transformation is specified. The chemical consequences of the str uctural metastability have been demonstrated by promoting of industria lly important processes, namely non-oxidative and oxidative decomposit ion as well as direct leaching of mechanically activated chalcopyrite.