Zirconium tetrafluoride monohydrate

Qua.driva.Ient, Zirconium tetrafluoride is prepared by fluorination of zirconium metal, but this is hampered by the low volatility of the tetrafluoride which coats the surface of the metal. An effective method is the halogen exchange between flowing hydrogen fluoride gas and zirconium tetrachloride at 300°C. Large volumes are produced by the addition of concentrated hydrofluoric acid to a concentrated nitric acid solution of zirconium zirconium tetrafluoride monohydrate [14956-11-3] precipitates (69). The recovered crystals ate dried and treated with hydrogen fluoride gas at 450°C in a fluid-bed reactor. The thermal dissociation of fluorozirconates also yields zirconium tetrafluoride. 

Zirconium tetrafluoride dissolves in dilute acid without hydrolysis, and can be recovered as the monohydrate [14956-11-3] by crystallization from nitric acid solutions. If the solution is acidified with hydrofluoric acid, ZtF 3H20 [14517-16-9] crystallizes at 10—30 wt % HF HZtF 20 [18129-16-9] crystallizes at 30—35 wt % HF, and at higher HF concentrations H2ZtF -2H20 [12021 -95-3] can be recovered. 

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