Reduction of Manganese sea nodules with noncoking coal

Process feasibility studies have been initiated to determine the possibilities of extraction of nickel, copper and cobalt from manganese sea nodules by coal reduction followed by ammoniacal leaching route. High volatile non-coking coal has been found to be an effective reductant for selective reduction of oxides of manganese sea nodules. The aqueous ammonia-ammonium carbonate leaching of the reduced sea nodules resulted in over 93.0%, 92.0% and 65.0% recovery of nickel, copper and cobalt respectively as complex ammines, while rejecting iron and manganese in the residue. Effect of various parameters for roasting and leaching in extraction of nickel, copper and cobalt from manganese sea nodules was studies and is reported in this paper.