Studies on the extraction of nickel from the nickeliferous laterites of Badampahar area, Orissa

A low-grade nickeliferous laterite from Badampahar area of Orissa analysing 0.42% NiO, 41.8% Fe2O3, 15.5% SiO2, 22.4% Al2O3, 3.4% Cr2O3, 0.27% V2O5 and a trace of cobalt was taken up for studies on nickel extraction. The crushed ore was reduced by hydrogen and leached with ammoniacal ammonium carbonate solution in presence of oxygen. Various factors studied include the effects of reduction temperatures, ore size, reduction rate, gas rate, kinetics of pre-conditioning and leaching as well as the leaching efficiencies of different ammonium salts. A maximum of 51% nickel recovery was obtained by reducing -170 mesh (B.S.S) size of ore at 650°C for a period of 90 minutes and leaching the pre-conditioned ore for 3 hours with a solution containing 7.5% NH4OH and 7.5% (NH4)2 CO3. (Miss S. Samanta, Senior Scientific Assistant, Mr. R.N. Misra, Scientist, Mr. P.P. Bhatnagar, Scientist, National Metallurgical Laboratory, Jamshedpur)