New prospective for the utilisation of Indian lateritic chromite overburden

Abstract

Nickel laterites form ~75% of known nickel resources whereas majority of nickel is produced from sulphide sources. Nickel bearing laterite and chromitiferous overburden are the only source of nickel available in India. In India, 5,000,000T of such overburden is generated each year in addition to the 140,000,000T that has already been accumulated over several years of mining and it is estimated to increase with the consumption of chrome ore. With the depletion of sulphide deposits and for the future supply of nickel, the industry must develop for the utilization of laterite ore bodies, especially limonite deposits. In this study, the recovery of nickel associated within the goethite was attempted by employing combination of physical and pyro-metallurgical route from the lateritic ore received from Sukinda region of India. The rejects of the beneficiation process contains chromite which can be used as a feed for the ferro chrome plants. Through physical beneficiation the iron enrichment achieved was 52.74% with a weight percent recovery of 59.67% having Ni-0.9% from the feed assaying 46.73% Fe (T), 0.76% Ni. This beneficiated overburden was used as a feed for the production of pig iron nuggets. Composite pellets of overburden containing lime and coal were reduced at 1400°C for the production alloy pig iron nuggets. The nuggets produced from this route contain C~ 3%, Ni~1.7%, Cr~1.5% and Fe-Rest. Recoveries of iron, chromium and nickel are >95%, >95% and ~30%, respectively.