METHOD OF REMOVING SULFUR IN NICKEL LEACHING PROCESS Russian patent published in 2004 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: invention relates to removing sulfur formed when leaching nickel matte. The latter operation is carried out in a series of steps using anolyte obtained during electrochemical removal of nickel to form nickel sulfate solution, which is then routed to electrochemical recovery of nickel and recovery of sulfur formed in electrochemical reduction of nickel from anolyte by neutralizing sulfuric acid with neutralizing agent. Part of anolyte obtained during electrochemical reduction of nickel is routed to sulfur recovery process. As sulfuric acid- neutralizing agent, calcium-based agent is utilized and gypsum formed in this operation is isolated from solution. Part of anolyte, namely 30-60%, is neutralized using, as neutralizing agent, burnt lime, limestone, or their mixture. Neutralized anolyte almost saturated with gypsum is extracted to remove gypsum using, as extraction agent, di-2- ethylhexylphosphoric acid. Calcium is removed after extraction in the form of calcium chloride. Calcium-free neutralized anolyte is routed to cobalt removal operation. EFFECT: enhanced process efficiency. 10 cl, 1 dwg