A new strategy of one-step sequential extraction of copper cyanide complex ions from cyanide leach solutions

Copper cyanide complex ions in cyanide solution of gold extraction by cyanidation will worsen the recovery of gold. Therefore, phosphate-based P204 ionic liquids (ILs) with different cationic carbon chain structures were synthesized and applied to the extraction of copper cyanide complex ions in cyanide solutions. During the extraction process, due to the self-assembly actuation by ILs, macroscopic white solids rich in copper cyanide complex ions are formed at the phase interface. Meanwhile, the solid phase loaded with copper cyanide complex ions can be separated by simple filtration without further stripping. The extraction behaviors were systematically studied in the present work. The results show that more than 97 % of copper cyanide complex ions by ILs P204-N4441 were extracted under the optimum extraction conditions. Meanwhile, the Self-assembly extraction mechanism was investigated detaily, the SEM, mapping EDS, FT-IR, and XPS analyses reveled that the potential mechanism of extraction for copper cyanide complex ions is coordination reaction. It is worth noting that the extraction efficiency of self-assembly organic phase remains 78.45 % after three cycles, which shows that the self-assembly extraction system has good reusability.