Mechanisms of extraction and separation of zirconium and hafnium by DIBK-P204 system

To master the chemical behavior of the extraction of hafnium and zirconium in the mixture of diisobutyl ketone(DIBK) and P204,the characteristics and mechanism about the extraction of zirconium and hafnium by DIBK-P204 system in thiocyanic acid(HSCN) medium were studied through the methods of slope coefficient and saturated volumetric.The results show that hafnium is extracted preferentially by DIBK-P204 system,the synergistic extractive effects are found,and the extraction reactions follow the mechanism of the addition reactions.The composition of extracted complex is determined as n(Zr4+(Hf4+)):n(P204):n(DIBK)=1:2:1 and the extracted complexes are identified as Zr(SCN)3 HA2 DIBK and Hf(SCN)3 HA2 DIBK,and the possible synergistic extraction complex structures are suggested through infrared spectrum analysis of the loaded organic phase.The extraction and separation effect of zirconium and hafnium can be improved with synergistic mixture of DIBK and P204.