Abstract
There was determined kinetics of leaching process for real industrial sample of calcined waelz-oxide of zinc production. There was established mechanism of the main reaction. The process of dissolution of solid phase particles could be arbitrary differentiated on two stages. In the initial point of time the reaction propagates in external diffusion regime on topochemical mechanism. On the second stage of leaching is occurred alteration of process’ mechanism, as evidenced by marginal character of dependence of zinc extraction on time, reason of which is formation on the surface of dissolved particles reaction products, developing badly penetrable films. Limiting stage in this case is internal diffusion.