Thiourea leaching of silver from mechanically activated tetrahedrite

The thiourea leaching of silver from a tetrahedrite concentrate mechanically activated in a planetary mill or an attritor was studied. It was found that the two types of equipment gave rise to different rates of new surface formation and of crystal structure disordering, The rate of thiourea leaching of silver from tetrahedrite (Cu,Ag)(10)(Zn,Fe)(2)(Sb,As)(4)S-13 is a structure-sensitive quantity, while the dependence of the rate constant of leaching on the empirical coefficient S-A/(1 - R) (S-A = specific surface, R = disordering of tetrahedrite structure) exhibits a linear character with equal slope for both types of mills. The results are also of prognostic character because they enable us to propose suitable equipment for intensive grinding depending on the demand for fineness or reactivity of the solid substances.