ELECTROWINNING OF NICKEL IN THE PROCESSING OF POLYMETALLIC SEA NODULES

As the land based reserves for nickel in India are meagre its extraction from sea nodules will assume increasing importance in the coming years. In the processing of polymetallic sea nodules by the reduction roast/ammonia leach/solvent extraction route, the recovery of nickel by electrolysis was considered. This led to the optimization of the parameters for electrowinning of the metal from synthetic solutions. The simulated condition was subsequently applied to win the metal from actual nickel pregnant electrolyte obtained during the treatment of ammoniacal liquor of polymetallic sea nodules using LIX 64N as an extractant. Energy consumption and current efficiency were worked out at current density in the range of 200-300 A/m2 in these experiments and deposit character of the electrocrystallised nickel was closely observed with the objective of producing metal of acceptable quality. © 1990.