PURIFICATION PHASES OF ZINC SULPHATE SOLUTION OBTAINED FROM NEUTRAL LEACHING PROCESS OF ZINC CALCINE

The aim of this paper is based in analyze of the zinc sulphate solution obtained from neutral leaching process of zinc calcine in "Trepca" and its purification from impurities. This solution besides zinc contains also and other impurities such as (Cu, Cd, Co, Ni, As, Ge, Sb, Se, Te, Ag etc.), which are with different concentrations. The sulphate solution can released from metal impurities based on the fact that they have higher electro - chemical potential than zinc and, as such, during the refining process they separate and precipitate in metallic form. Treatment of solution with appropriate technological methods technologically is very important in continuation of the electrolysis process and is accompanied by economic effects, because of non-ferrous and rare metals benefit. In this paper are described the phases of the purification process including acidic purification, cooling, needed materials and equipments for the refining process. Also, special attention is dedicated to the factors that have influence in the process development such as concentration, temperature, time, compressed air, etc