PURPOSE: To efficiently separate and recover Ru, by passing Cl gas through a waste material of an electrode, having an RuO2 coating and used in brine electrolytic industry while heating the waste material together with C powder to convert the substrate of the electrode into a chloride.
CONSTITUTION: An electrode having an Ru oxide coating on the surface of a substrate, e.g. Ti, TiO2, Co2O3, Al2O3 or SiO2, is used as an electrode used for electrolysis of brine. An electrode having the Ru oxide coating consumed and deactivated by use for a long time is replaced by a new electrode. Since expensive Ru is left in the used old electrode, the electrode is, together with an electrode substrate, e.g. Ti, made into a mixture 1 containing added carbon and put in a chlorination vessel 4. Cl gas is then fed from an inlet pipe 5 through glass fibers 3 while heating the mixture 1 at 600W1,000°C in an electric furnace 2. The Ti or TiO2 in the electrode substrate is reduced into a chloride, volatilized and cooled in a cooling pipe 6, liquefied and introduced into a tank 7. Solid residual materials in the vessel 4 are separated by specific gravity into C powder and Ru to recover the Ru in good yield.