Solvent Extraction Separation of Zr and Hf from Nitric Acid Solutions by PC 88A and Its Mixture with Other Extractants

Solvent extraction for the separation of zirconium and hafnium from strong nitric acid solution has been investigated by using several organophosphorous acids (D2EHPA, PC 88A and Cyanex 272) and its mixture. Among the single extractants, PC 88A showed the best performance for the extraction and separation of the two metals. Mixtures of PC 88A with neutral, cationic and anionic extractants were tested in order to improve the separation between Zr and HE Mixtures of PC 88A with TBP or Versatic 10 or TOA did not show much influence on the extraction and separation of the two metals. Extraction efficiency of both Zr and Hf was markedly enhanced by using the mixture of PC 88A and TOPO. The mixture of PC 88A and LIX 63 led to synergism in the extraction of Zr, while antagonism occurred in the extraction of Hf. The highest separation factor of 46 was obtained from 2 M HNO3 solution by the mixture of PC 88A and LIX 63.