Solvent extraction separation of hafnium with 4-methyl-3-pentene-2-one

A new method for the extractive separation of hafnium from zirconium is presented. Zirconium is extracted with pure mesityl oxide from 4M nitric acid/4M sodium nitrate medium, followed by extraction of hafnium with mesityl oxide from 0.4 M hydrochloric acid/2M ammonium thiocyanate medium. It is possible to accomplish clean separations of Hf from Zr in ratios from 1:20 to 1:200. The separation of hafnium from commonly associated elements such as scandium, yttrium, uranium, thorium, alkali and alkaline earth metals in 500:1 weight ratio to hafnium is also possible. (author)