Recovery of Metal Values from Low-Grade Heterogenite with Reductive Ammonia Leaching Method

Reductive ammonia leaching method was used to recover Cu and Co from heterogenite. The influences of the reductant quantity, leaching temperature, the concentration ratio of NH₃ to (NH₄)₂SO₄, leaching time and liquid-solid (L/S) ratio on leaching rate of cobalt and copper were investigated. The optimal conditions at which the leaching rate of copper and cobalt were 96.07%, 98.24% respectively and that of Fe, Mg and Al were almost 0 were as follows: time = 5 h, T = 50°C, the amount of ammonia is 1.2 times of theorrtical, C(NH₃):C [(NH₄)₂SO₄] =1:3, L/S ratio = 3:1, and the dosage of Na₂SO₃ is 0.5 times of the heterogenites mass.