LIX 973N diluted with Iberfluid was used to co-extract copper and nickel from ammoniacal/ammonium carbonate aqueous media. The influence of equilibration time, temperature, equilibrium pH and extractant concentration on the extraction of both metals has been studied. It was observed that neither copper nor nickel extraction is sensitive to temperature and equilibrium pH, however nickel extraction equilibrium is reached at a longer contact time (20 min) than that of copper (5 min), in addition nickel extraction depends greatly on the extractant concentration in the organic phase. For a solution containing 3 g dm−3 each of copper and nickel and 60 g dm−3 ammonium carbonate, conditions were established for the co-extraction of both metals, ammonia scrubbing and selective stripping (with H2SO4) of nickel and copper. Using the appropriate extractant concentration the yield (extraction stage) for both metals is near 100%, whereas the percentage of nickel and copper stripping is also almost quantitative.

We thank the CSIC (Spain) for support to carry out this work and Mr JL Bascones and Mr M LoÂpez for their help. One of us (FJA) also thankfully acknowledges Dr Schwab (Henkel KGaA, Germany) for supplying sample of LIX 973N.

Peer reviewed