IR AND XRD STUDY OF THE TRIBOCHEMICAL REACTIONS OF COPPER-SULFATE WITH ALKALI-HALIDES

Tribochemical reactions of CuSO4 · 5H2O and CuSO4 during milling with KCl, KBr, and KI have been studied by IR and XRD techniques. The reactions are rather similar for the hydrated and anhydrous salts, but proceed faster with the former. With KCl, the reaction leads directly to CuK2SO4Cl2 also known as the mineral chlorothionite. With KBr, the mixed salts CuK2(SO4)2 · 2H2O and CuK2 (SO4)2 · 6H2O are first obtained which transform to a new compound upon further milling, that we postulate as CuK2SO4Br2. With KI, there is a fast reaction to a mixture of CuK2(SO4)2 · 6H2O, γ-CuI, and I2, later proceeding to K2SO4, γ-CuI, and I2. © 1993 Academic Press, Inc.