1991 Volume 17 Issue 6 Pages 1104-1109
Continuous operation of the liquid surfactant membrane (LSM) process was tested for chromium (VI) recovery from a sulfuric acid solution using one-stage and threestage mixer-settler extractors. The organic (membrane) phase of LSM was kerosene with 12 vol. % 2-ethylhexyl alcohol and 2 vol. % polyamine (Exxon Chem., ECA4360J) without extractant.
Chromium in the external aqueous phase was successfully transported and concentrated into the internal aqueous phase containing lithium hydroxide. It was found that multistage operation was effectively decreased the chromium concentration in the external aqueous phase, and that chromium concentration in the internal aqueous phase was further increased when half the emulsion flow from the settler was recycled to the same extractor. The experimental results of the continuous operation were found to be satisfactorily simulated by a model of the chromium transport with experimental parameters determined from batch experiments.
