Separation of Zirconium and Hafnium from Chloride Solution Using Strongly Basic Anion Resins

The ion exchange process was employed to separate zirconium from hafnium in solution. To this end, four effective parameters, involving resin type, HCl concentration, Time, and initial zirconium concentration, were selected as the main variables. The sorption of zirconium and hafnium in the presence of six commercial macroporous anion exchangers of Dowex and Amberlite series and different HCl concentrations of 8-12 M were investigated. Furthermore, the distribution ratio, as a function of time in the range of 0.5-3 h and initial zirconium concentration of 500-3000 mg/L, was studied. The highest separation factor of 10.29 was obtained under equilibrium conditions in the presence of Amberlit CG-400II Ion Exchange Resin (IER) at a concentration of 9.5 M hydrochloric acid. Equilibrium isotherms of the system under optimized conditions were analyzed by Langmuir and Freundlich's adsorption models. The experimental data are well-described by the Langmuir equation for both zirconium and hafnium.