A New process for the enrichment of nickel in Sukinda chromite overburden ore

Chrontite Over Burden (COB) ore from .Sukinda taller, Orissa is too lean in nickel concentration to he exploited for the extraction of nickel. The average nickel concentration in the COB ore lies in the range of 0.4-0.6%. An acid leaching route at atmospheric prsssure has been developed for screening out silica as insoluble. Metal values in the leach liquor are retrieved as hydroxides by appropriate manoeuvring of pH. The metal hydroxides are converted to corresponding oxides by calcining at 900°C. The resultant nickel content in the mixed oxide has been consistent1 ' .found to he 1.6% and above. This product star he directly used as a starting material for the preparation of ferro-nickel.