Extraction and pre-concentration of lead from copper by emulsion liquid membrane technique using an ionic liquid

Abstract

The study of the recovery process of lead from aqueous nitrate medium using emulsion liquid membrane technique was achieved by the optimization of the extraction and pre-concentration of Pb(II) ions. This has been conducted by the method of optimizing one experimental parameter at a time. The chemical process of recovery consists of a quaternary amine salt (Aliquat 336) as ionic liquid extractant and a non-ionic surfactant (Tween20) as reagent for dispersion and emulsion formation. Thus, several experimental parameters such as carrier concentration, surfactant concentration, time and stirring speed of feed phase, initial concentration and pH of feed concentration phase were studied. Pb(II) ions extraction was optimized using tri-n-octylphosphine oxide (TOPO) as the solvating organophosphorus compound in the emulsion phase. From the results, the lead ions were extracted at 92 ± 0.04% by Aliquat 336 in the presence of TOPO. For the stage of Pb(II) pre-concentration, the nature and concentration effects of the stripping solution were studied. So, the loss of the Pb(II) ions in the membrane phase was minimal when using the nitric acid solution as a stripping solution. It was preconcentrated at 83.55%. The separation experiments of Pb(II) from Cu(II) were given on the basis of the optimal conditions of lead(II) recovery. Thus, the separation factor of lead over copper was equal to 1.47.