Extraction of cobalt by CTMAB-pentanol-heptane-HCl Winsor II microemulsion systems

The influence of the concentration of cosurfactant (pentanol) and surfactant (CTMAB) on the water content of the microemulsion was studied, and the proper microemulsion extraction system has been worked out. The effect of the concentration of CTMAB, pentanol, ammonium thiocyanate, and of the volume ratio of aqueous to microemulsion (R), temperature and the contact time on the extraction yield were investigated. The extraction yield was above 93% for R = 5. In the back-extraction step, the cobalt extracted in the microemulsion phase was precipitated and the microemulsion was recycled for further use. This study shows that it is possible to extract cobalt ions effectively from an NH4SCN aqueous solution by using Winsor II systems.