Galvanic Interaction Between Galena And Manganese Dioxide In Hydrochloric Acid Medium Part II - Particulate Leaching Studies

Abstract

Particulate leaching of galena and manganese dioxide (pyrolusite mineral) was conducted in hydrochloric acid (0.1-0.2M) in order to observe the role of galvanic interaction between the minerals in the dissolution process. Electrochemical parameters determined earlier from polarization measurements were correlated to the observed dissolution data. Dissolution of MnO2 alone was negligible. Dissolution of galena in the absence of MnO2 was non-oxidative and the dissolution improved in the presence of MnO2 with simultaneous dissolution of manganese because of galvanic interaction. Galvanic interaction was not up to the extent as expected on the basis of polarization studies, presumably due to insufficient galvanic contact between the minerals in a particulate leaching system. Consumption of hydrochloric acid was studied under various conditions. Non-oxidative dissolution could be prevented and consumption of hydrochloric acid could be minimized by leaching the two minerals together. Reasonably good dissolution of both the minerals took place at room temperature and low hydrochloric acid concentration.