Abstract
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.