Extraction of copper from ammoniacal solutions into emulsion liquid membranes using LIX 84 I®

Copper was extracted from ammoniacal-ammonium sulfate solutions using emulsion liquid membranes (ELMs) with ketoxime LIX 84 I as carrier. The extraction process was very fast and almost quantitative extraction was observed in most cases in just two minutes contact between the feed and the emulsion phases. The optimal pH for extraction was found to be pH 8.1, which limited the free ammonia transport through the membrane. Loading capacity of the membrane governed the extraction rates. High carrier concentration and treat ratio led to faster recoveries. Even when copper concentration in feed solutions was > 3000 mg/L, extraction with ELMs containing 10% (v/v) LIX 84 I in the oil phase and a treat ratio of 1:6 resulted in almost 88% copper recovery in just three minutes of contact.