Abstract: A zirconium sponge contaminated with unreacted magnesium and by-product magnesium which is produced as a regulus in a Kroll reduction process is purified by:distilling the magnesium and magnesium chloride from the regulus at a temperature of above about 800.degree. C. and at a pressure less than about 10 mmHg;condensing the magnesium and the magnesium chloride;backfilling the sysem with a gas; andrecirculating the gas between a vessel containing the purified zirconium sponge and a condenser containing the magnesium and magnesium chloride.In preferred practice, the recirculating gas is an inert gas such as argon or helium and the system is backfilled during the distillation step.The zirconium sponge is purified in shorter times and adsorbs less impurities from the air in subsequent handling.