Carbothermic reduction kinetics of Ka’oje (Nigeria) manganese ore

The kinetics of carbothermic reduction of manganese ore from Ka’oje deposit has been established. X-Ray diffraction analysis of the as-mined ore samples affirmed the presence of pyrolusite as the major manganese mineral in the ore, existing alongside with iron mineral present as hematite optically identified by transmitted infrared light microscopy. Samples with particles size ranges—106 μm were isothermally treated using charcoal of 52.17% carbon content as the reductant. The treatment was carried out at 550˚C, 600˚C, 650˚C and 750˚C with varied roasting retention time. Ore-mineral reduction kinetic model equations were developed using the generated thermal data. Results showed that the apparent activation energy (Ea) of the chemical reaction controlled reduction was 19.99 KJ/mole using the diminishing area rate equation. Obtained Ea values for diffusion controlled reduction of the ore-minerals were 36.28 Kj/mole and 29.56 KJ/mole using Jander and Ginsthing-Brounshtein equations respectively. These hereby established reduction susceptibility of the manganese oxide mineral from higher oxide to lower oxides meant for further hydrometallurgical treatments