Process of recovering anhydrous zirconium tetrafluoride

In a process for making substantially anhydrous zirconium tetrafluoride by drying zirconium fluoride dissolved in aqueous hydrofluoric acid and subsequently calcining the same to remove the water of crystallization in said zirconium fluoride, the improvement wherein the solution is sprayed continually into a fluidized bed oven with a bed of granulated zirconium fluoride and evaporated and zirconium fluoride containing water of crystallization is calcined in a fluidized bed oven with a bed of granulated zirconium fluoride at 220.degree.-300.degree. C. and drawn off from said fluidized bed oven, continually, as granulated product.