BIOLOGICAL AND CHEMICAL-PROCESSING OF LOW-GRADE MANGANESE ORES

Leaching of manganese with aqueous SO2 has been investigated at a laboratory scale by percolation at room temperature as a function of acid concentration solution flow-rate and time. The critical parameters were ascertained to be pH and redox potential in order to ensure the best conditions for the dissolution of MnO2. With the proper choice of the process variables, maximum manganese recovery is achieved in 15-20 days of leaching. A bioleaching process was also developed using different microorganism for extracting manganese from low grade domestic resources. The quantitative dissolution of manganese dioxide catalyzed by heterotrophic microorganisms was obtained in 20 days. The oxidation state of manganese in liquor was determined by polarographic techniques to be divalent. The consumption of ore and the presence of microorganisms was detected by scanning electron microscopy. The effect of the biotreatment of the ore was also investigated in petri plates. © 1990.