Upgrading of a Nigerian Ixiolite ore to Columbite by Sulphuric acid treatment

Abstract

A quantitative leaching of a Nigerian Ixiolite ore in sulphuric acid medium was carried out and the effect of some parameters such as acid concentration, temperature and particle size was evaluated as a function of time. The experimental results obtained showed that the Ixiolite dissolution increases with increasing acid concentration, temperature, leaching time and, decreases with particle size. With 3 mol/L H2SO4 solution, 71.14% of the ore reacted within 120 minutes at 80°C.The kinetics of dissolution of the mineral was also examined and the observed effects of the operating variables on the leaching rate were consistent with the diffusion controlled kinetic model. The calculated activation energy for the leaching process was 24.40 kJ/mol with the reaction order of 0.5, supported the proposed model. Detailed characterization of the ore before and after leaching were carried out. At optimal leaching conditions, thermodynamic feasibility of the conversion of raw Ixiolite to Columbite of industrial value, as confirmed by X-ray diffraction (XRD) technique is possible.