Copper extraction from chloride solutions with mixtures of solvating and chelating reagents

Equimolar mixtures of N,N,N',N' -tetrahexylpyridine-3,5-dicarboxamide (L) w ith 2-hydroxy-5-t-octylbenzophenone oxime or 1-phenyldecane-1,3-dione (HB), were used to extract copper from chloride solutions of various concentrati on of chloride ions. Chloride ions were then scrubbed out with water or amm oniacal solutions and copper was transferred from the solvate CuCl2L2 to ch elate CuB2. Both studied systems permit effective extraction of copper and removal of chloride ions from the organic phase. Some protonation of solvat ing reagent L occurs, however, when copper is stripped from the chelate wit h hydroxyoxime. This negative effect can be suppressed when 1-phenyldecane- 1,3-dione is used as a chelating agent. The scrubbing of chloride ions must be then carried out with ammoniacal solutions to avoid simultaneous stripp ing of copper.