Solvent extraction of zirconium from nitric-hydrochloric acid solutions using TBP

Solvent extraction is a commercial method for production of pure materials such as zirconium and hafnium and their compounds from multi-component scrubber solution. In the extraction of zirconium and hafnium salts from HNO3, HCl, HClO4 and H2SO4 into neutral organophosphorus compounds (NOPC) - such as tributyl phosphate (TBP)- in case using mixtures of inorganic acids, NOPC extracts zirconium and hafnium with separation factor con- siderably exceeding the corresponding value for extraction from solution of individual acids. A still higher separa- tion level is obtained when using mixture of acids, especially those of nitric-hydrochloric acids. In this paper, the extraction of zirconium from solution containing nitric-hydrochloric acids using TBP in treated kerosene as diluent has been studied. The following parameters have been investigated: effect of extractant, nitric-hydrochloric acids and zirconium concentrations, mixing time, acidification of organic phase, the organic/aqueous phase ratio and tem- perature on the extraction of zirconium.