基于生物浸提技术的钴白合金中铜和钴的浸出效果及浸出机理

The three mixed bacterial systems of At, Af and Lf were used to extract copper and cobalt from cobalt white alloy in a non-ferrous metal plant in Henan to investigate the leaching rate and leaching mechanism of copper and cobalt under different contact conditions of non-contact leaching and contact leaching with different solid-liquid ratios. The results showed that under the non-contact leaching with 1% solid-liquid ratio, 100% Co was leached and 77.42% Cu was leached, and their leaching mass concentration were 1356.14 and 837.19 mg·L⁻¹, respectively. After 10 cycles of leaching, the concentrations of copper and cobalt in the final leaching solution were 7 358.67 mg·L⁻¹ and 12 877.25 mg·L⁻¹. After 5 days of contact leaching with 4% solid-liquid ratio, 100% cobalt was leached, while copper basically remained in the residue, which can provide a reference for the stepwise leaching of cobalt white alloy. Comparing the occurrence of copper and cobalt in the leaching residue of the contact leaching and non-contact leaching experiments in biological leaching, it is determined that the leaching of cobalt in cobalt white alloy is the direct effect of biological acid, and the leaching mechanism of copper is the common combination of biological acid and Fe³⁺ effect. In the leaching system with the participation of bacteria, there is a cycle in which copper leaching consumes Fe³⁺ and converts Fe³⁺ into Fe²⁺ and bacteria convert Fe²⁺ into Fe³⁺. The use of biological leaching cycle enrichment technology provides a reference for the efficient recovery of copper and cobalt in cobalt white alloy.