Preparation of DMHMP Levextrel resin and separation of zirconium and hafnium by extraction chromatography in HNO3-HCl mixture

Abstract

Separation of zirconium and hafnium with very similar chemical properties is very important and difficult in the field of nuclear science, technology and engineering. Herein, a novel extraction chromatographic method was developed to quantitative separation of zirconium and hafnium using di-(1-methylheptyl)methylphosphonate (DMHMP) Levextrel resin as the stationary phase and HNO3-HCl mixture as mobile phase. The DMHMP Levextrel resin was prepared by the suspension polymerization technique. The extraction behavior of zirconium and hafnium was systematically investigated by liquid-liquid extraction method from HCl, HNO3 and HNO3-HCl solutions, respectively. It has been found that a high separation factor (SF) of 47 for Zr/Hf can be obtained in 2 M HNO3-2 M HCl solution. Under the optimum conditions, extraction chromatography was performed to separate zirconium and hafnium in different weight ratios. The effects of amount of carriers and interference ions on the chromatographic separation were examined. The recovery and mutual decontamination factor (DF) of both elements were determined. It exhibits Zr and Hf can be completely separated from each other. And the high recovery of 98–102%, mutual decontamination factor (DF) of 104, and high selectivity for both elements against a large excess of interference ions were obtained. This work provides an effective extraction chromatographic procedure to concentration and separation of Zr and Hf.