The Extraction of Hafnium and Zirconium from Cyrtolite

SuBUITTED BT EdWIN M. LarSEN, W. CoNABD FERNEUUS, f AND LaURENCB L. QuiLLt 

The lack of a convenient method for the separation of hafnium from zirconium has undoubtedly been the principal deterring factor in the development of the chemistry of hafnium. Methods that can be used for the separation 

The following procedure involves the fractional precipitation of the phosphates in dilute acid solution. This direct precipitation procedure has not been used heretofore because of the gelatinous character of the usual phosphate precipitate, and the lack of a convenient method for converting the insoluble phosphates to soluble compounds for reprecipitation. These difficulties are overcome in the following process. 

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