Separation And Recovery Of Copper And Nickel From Low Grade Ore Heap Leaching Solution

Two kinds of process, iron powder replacement and step precipitation, had been studied for selectively recovering copper and nickel from heap-lixivating liquor.It shows that mechanical activation makes the activity of iron increase sharply and enhanced its replacement reaction ability. Succeedingly, the recovery of copper and nickel is improved. Among three kind of activator, vibrating mill, planetary centrifugal mill and oscillate mill, the last one shows the best activation effect.Under the following best conditions, 98% of copper and nickel in the solution can be recovered:10-15minutes' activation in a oscillate mill.3 times equivalents iron respects to copper and nickel in the solution.temperature of 90℃.The step precipitation process includes three steps: enrichment of copper and nickel, disposing of iron and, Cu/Ni separation. By adding (NH₄)₂S , 99% of copper and nickel can be concentrated in precipitation, while Mg is kept soluble. The precipitation obtained is roasted and redissolved. Above 98.5% of iron is removed by goethite method. Copper is separated using Na₂S₂O₃ as precipitator. The ratio of copper to nickel in precipitation is 25, while the ratio of nickel to copper in the treated solution is 150. The total recovery of copper and nickel exceeds 95%.