Application of sulphuric(VI) acid leaching for magnesium removal from zinc concentrate

In this paper the results of investigation of magnesium removal from raw zinc concentrate have been presented. The raw materials derive from ZG Trzebionka and ZGH Bolesław. The differences in zinc and magnesium contents are characteristic of these materials. The experiments were carried out in the periodical reactor at 25°C using the H2SO4 solution of 20, 50, and 70% (v/v) concentration. The weight ratio of the solid phase to the liquid phase was 1:10 and 1:2. On the basis of the experimental results it can be stated that the application of sulphuric(VI) acid leaching permits to increase the zinc yield in Zn-Pb ore processing. This method permits to obtain zinc concentrate containing more than 60% Zn and MgO below 0.3% and CaO about 1.4%.