KINETICS OF MANGANESE LEACHING DURING PRESSURE ACID LEACHING OF LOW GRADE MANGANESE ORES

The kinetics of pressure leaching low grade manganese ore was studied. The effects of agitation rate, particle size, temperature, pressure, initial acid concentration and pyrite content in solid mineral on the leaching rate of manganese were examined. The experiment results indicate that the stirring intensity had no effect basically on the reaction process, manganese leaching rate increases with a decrease of particle size and an increase of temperature, total pressure, sulfuric acid concentration and pyrite content in solid mineral. It was found that the reaction kinetic model follows the shrinking core model of chemical reaction control and the apparent activation energy was determined as 43.4 kJ/mol. The reaction orders with respect to sulphuric acid concentration and total pressure were 1.428 and 0.864, respectively.