Study of Zinc-Lead-Containing Cake Leaching Features

The research subject is an intermediate product of zinc production containing lead, zinc, iron, copper, and silver. Thermodynamic analysis is performed for all probable transformations during sulfuric acid leaching, and a Purbe diagram is plotted. The study of uncovering lead-containing middlings is performed in two stages: the first is leaching with sulfuric acid with density 250 g/dm³ (S:L = 1:4) at 80°C for 2 h. At the second stage, washed cake is leached with a complexing solution (Trilon B) with the aim of maximum zinc transfer into the liquid phase. Conditions are selected on the basis of test results for process optimization by an experimental planning method, and from analysis of response surface, modeling the dependence of the degree of leaching on pulp density and complexing agent concentration.