Calciothermic Reduction of Zirconium Oxide in Molten CaCl₂

Abstract

The reduction of zirconium dioxide using liquid calcium and molten calcium chloride was investigated. The study focusing on the influence of reductant amount, reaction time, CaCl₂ amount, and temperature on the reduction process. Zirconium powder with oxygen content less than 800 ppm was obtained at 1 100°C after 3 h and by using two times the theoretical amount of Ca and four times that of CaCl₂. The reduction reaction of ZrO₂ was found to be multi steps process through the formation of intermediate phase CaZrO₃. The morphology of the obtained zirconium was observed to be highly affected by the reaction temperature.