APPLICATION OF LIX-84 FOR SEPARATION OF COPPER, NICKEL AND COBALT IN AMMONIACAL LEACHING OF OCEAN NODULES

The ammoniacal leaching is apparently considered an attractive approach to process polymetallic sea nodules wherein copper, nickel and cobalt are solubilised forming the ammine complexes. To separate these metals, LIX 84, an oxime extractant, was tried from the synthetic solutions. The loading capacity of this solvent for individual metal and ammonia extraction was determined and compared with that of LIX 64N. Preferential extraction of copper over nickel from a mixed aqueous solution was observed. The kinetic studies for the extraction of metals were undertaken to arrive at the retention time appropriate for this operation. Before metal stripping, the mode of ammonia scrubbing from the organic was worked out using acid or a combination of ammonia-dilute acid as the reagents. The coextraction of nickel and copper and their selective stripping were considered to explore the possibility of separating Cu, Ni and Co from ammonia-ammonium carbonate medium. The separation of these metals from the ammoniacal leach liquor of sea nodules was also attempted.