Research On The Purification Of Zirconium From Zirconium Dioxide By Liquid-Liquid Extraction Method With Tributyl Phosphate Solvent

The study of hafnium separation from zirconium and purification of zirconium by liquid-liquid solvent extraction method bases on the selective extraction, capacity and high stability of tributyl phosphate solvent (TBP). Technical grade ZrO2 powder, imported product (about 2% Hf content), is mixed with NaOH by 1:6 mole ratio, baked at 700oC in 2 hours. The mixture of zirconate and hafnate Na2Zr(Hf)O3 was dissolved in water, acidified by HNO3 to transfer to Zr(Hf)O(NO3)2. The obtained solution is used for the hafnium separation and purification of zirconium investigation. The influence of acid concentration (HNO3) in initial solution (feed solution) on the efficiency of zirconium extraction, the effect of the extraction solvent concentration (TBP) to zirconium distribution ratio and the effect of concentrations of mixture of components (Zr and Hf) in initial solution on zirconium extraction performance and also effect of the ratio between organic and aqueous phase to zirconium distribution coefficient were carried out in this paper. Established optimum conditions of the interruptive solvent extraction in experimental scale including metal contents in initial solution CHf/Zr is 30 g/L; TBP concentration in kerosene is 60% by volume; the acid (HNO3) concentration in initial solution [H+] = 6 M; and organic : aqueous phases rate equal by 1:1. Conditions of the extracted scrubbing and extracted tripping also the continuous extraction process were studied as a first step. (author)