OBTAINING Zn<sup>2+</sup> FROM SPHALERITE CONCENTRATE

Valorization of zinc from polymetallic ores and concentrates is a very important branch in the metallurgical industry. Zinc is mostly extracted by hydrometallurgical methods. Leaching is most often done with the help of strong oxidizing agents, which can have a harmful effect on the environment. Certain cyclic oxidation systems, such as the Fe3+/Fe2+ couple, often fail to achieve a high level of zinc leaching, especially when it is in the form of sulfide. In this work, a new oxidation system was applied, which consists of MnO2 as the primary oxidation agent and KI as an supporting oxidation agent that serves to form the I2/I- oxidation cycle in the medium of sulfuric acid. The leaching experiment was performed under atmospheric pressure conditions, in the temperature range from 40 to 80 °C. The influence of KI concentration on the degree of zinc leaching was also examined. For the mentioned system, the degree of zinc extraction is 89.78% after 3 hours of leaching at a temperature of 80 °C. These results show that the MnO2-KI oxidation system has the potential to improve zinc extraction from sphalerite concentrates.