GB815245A - Production of zirconium tetrachloride - Google Patents

Abstract

Zircon sands, containing mainly zirconium silicate, are treated with a gaseous mixture of chlorine and sulphur, or a vaporized chloride of sulphur alone or in admixture with chlorine gas, to produce a crude zirconium tetrachloride and silicon tetrachloride which can be separated by distillation. The reaction temperature is generally between 700 DEG and 1200 DEG C. The zircon sands may be given a pretreatment to render them more easily reactive with the sulphur/chlorine reactant by: (1) fritting the zircon sand with soda ash preferably at 900 DEG C. to form sodium zirconium silicate (Na2ZrSiO5); (2) fritting the zircon sand with soda ash and extracting with dilute acid solution, preferably H2SO4 to remove the Na2O; (3) reacting the zircon sand with caustic soda at about 600 DEG to form sodium zirconium silicate which then may be reacted with the vaporized sulphur chlorine reactant; (4) extracting the caustic soda zircon reaction product of (2) with dilute acid to remove the soda before reaction with the vaporized sulphur/chlorine reactant. The crude condensed zirconium tetrachloride produced by the initial reaction and distillation can be purified by distilling off the impurities in an atmosphere of chlorine and then subliming the zirconium tetrachloride in a chlorine atmosphere.