Transport of cadmium ions from zinc plant leach solutions through emulsion liquid membrane-containing Aliquat 336 as carrier

The zinc plant purification cake (CINKUR Co., Turkiye) was leached with sulphuric acid. The transport of cadmium from this leach solution-containing zinc, iron, copper, aluminum, cadmium, nickel and cobalt through emulsion liquid membrane (ELM) using amine extractant dissolved in kerosene as a mobile carrier was studied. The ELM consists of Aliquat 336 as a carrier, Span 80 as a surfactant, commercial kerosene as organic solvent and 6 M ammonia solution as stripping solution. The study has highlighted the importance and influence of membrane composition for maximizing the extraction of cadmium. The influence of acid and cadmium concentrations of feed solution, type and concentration of stripping solution, mixing speed, potassium iodide (KI) concentration, carrier concentration, surfactant concentration and the effect of volume ratio of the stripping phase to the membrane phase was investigated. The optimal conditions for the transport of cadmium ions have been found. The results showed that it is possible to extract 90-99% of cadmium after 10 min contact time by using ELM from the acidic leach solutions, containing Fe, Al, Cu, Zn, Pb, Co and Ni ions, at the optimum operating conditions. (c) 2008 Elsevier B.V. All rights reserved.