METHOD OF PURIFYING HAFNIUM TETRACHLORIDE THROUGH SELECTIVE REDUCTION OF IMPURITIES Russian patent published in 2010 - IPC C01G27/04 C01G25/04 

FIELD: chemistry.

SUBSTANCE: initial hafnium tetrachloride, chloride salts, for example sodium or potassium tetrachloroaluminate, and an alloy-reducing agent are loaded into an ampoule made from borosilicate glass. Reduction of chlorides of impurities takes place in molten chloride salts at 250-450°C with their transformation into compounds which are less volatile than HfCl₄. The reducing agents used are binary or multi-component alloys of metals selected from the group: Zn-Mg with Mg content of 10-60 wt %, Sn-Mg with Mg content of 5-10 wt %, Pb-Bi-Sn with Sn content of 30-90 wt %, Zn-Sn with Sn content of 50-95 wt %.

EFFECT: high efficiency of the purification process and obtaining hafnium tetrachloride with high degree of purification from impurities.

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