Solvent extraction studies on cadmium Pt. 1

An extraction study was performed on tracer concentrations of cadmium halides in absence and presence of sulphuric acid. Inert solvents, nitrobenzene, a long chain amine (Amberlite LA-2) and organophosphorus solvents (TBP and HDEHP) have been investigated. The comparative stability of cadmium chloride and bromide TBP solvates were determined. The presence of sulphuric acid was found to enhance considerably the extraction of cadmium halides by nitrobenzene, Amberlite LA-2 and TBP. The mechanism of extraction has been discussed in light of the obtained results. The systems studied involved halide ions (Cl, Br and I), sulphuric and phosphoric acids. In these systems extraction was negligible for all nonpolar solvents, considerable for nitrobenzene and very high for Amberlite LA-2 and TBP. Work has been carried out for both micro and macro scales in case of sulphuric acid system, and only for the microscale in case of phosphoric acid system, because of the limited solubility of cadmium phosphate in aqueous solutions. (T.G.)