Recovery of Copper, Nickel and Cobalt from Ammoniacal Leach Liquors Obtained by Direct Ammonia Leaching of Sea Nodules

Abstract

At the NMI_, continuous studies are going on in the ammonia leaching of the polymetallic sea nodules. In the direct ammonia leaching process, sotuhilization of copper, nickel and cobalt occurs by formation of amine complexes in presence of a metal ion reductant. Separation and recovery of copper, nickel and cobalt from the above leach liquor was then carrie=d out by solvent extraction and electrowinning. Batch type shake-out as well as continuous expert vents were conducted with the adjusted composition of the actual leach liquors using 46` LIX-64N in kerosene. Copper and nickel were coextracted leaving cobalt in the raffinate. Loaded ammonia in the organic was removed by scrubbing with anunonium bicarbonate and dilute sulphuric acid. Nickel was then selectively stripped off with the spent electrolyte generated in the nickel electrowinning cell. Copper was subsequently stripped from the loaded organic with copper spent electrolyte, The optimised conditions thus established for all process streams are described.