Study for Production of Zirconium Sponge by Separated-Reduction Process

Abstract

Zirconium sponge is produced by Kroll process which is a single batch process in a two-part vessel, with the zirconium tetrachloride loaded into the top portion and the magnesium metal loaded in the bottom. In such system, the amount of zirconium which can be produced in a single batch is severely limited and feed of zirconium tetrachloride into the bottom portion can only be roughly controlled.

In the present study, hence, we embodied separated-reduction process which is a separated reduction vessel filled with magnesium and the sublimation vessel filled with zirconium tetrachloride for zirconium sponge production. The temperature of two vessels being controlled independently by separated heating device. It is observed that the zirconium sponge was formed at the surface of reduction vessel and the reaction rate between magnesium and zirconium tetrachloride was calculated at 131±15kg/h/m2. The zirconium sponge contains 800–1000 ppm of oxygen impurity, 60–300 ppm of nitrogen impurity after vacuum distillation. The recovery of on-grade zirconium sponge based on ASTM standard was about 58%.