On the basis of the performed experiments on leaching sulfide, oxidized, and mixed copper ores, a scheme of the cryogenic formation of oxidation zone of the Udokan deposit is proposed. It explains a wide occurrence of copper sulfates and increase in their fraction with depth of penetration into permafrost beds of predominantly acid sulfate solutions, whose copper concentrations can reach 20 and more g/l. The gravitational migration of nonfrozen concentrated Cu-sulfate solution through ice at a rate of 1-1.5 cm/month as well as slower diffusion migration of these solutions in subhorizontal direction is proved experimentally. With temperature variations within negative values, the process of leaching is drastically intensified because of wedging pressure in interstices, desintegration of ore and respective increase in reactional surface.
