Selective recovery of copper from copper-nickel sulfide concentrates by applying segregation technology

Copper can be selectively segregated from roasted copper-nickel sulfide concentrates. Conditions are reported for desulfurizing-roasting followed by segregation treatment to selectively reduce and segregate copper without nickel contamination. A process is described which is applicable for treating low grade sulfide concentrates such as are produced in Botswana (4.6 pct Cu, 3.1 pct Ni) and higher grade concentrates that can potentially be produced from sulfide deposits in Minnesota (13 pct Cu, 2.5 pct Ni). Steps include roasting to remove at least 97 pct of the sulfur, segregation treatment of calcine and flotation to recover a copper product, a middlings fraction which is recycled to the desulfurizing roast and a tailings fraction which can be subsequently treated for nickel recovery. LAMAR D. COFFIN, formerly Senior Research Metallurgist at AMAX Base Metals R&D, Inc., has retired.