Abstract: The foundry dust is fed to a first furnace atmosphere which is preferably at 1000.degree. to 1100.degree. C. With the dust pellet being continuously rolled around, it remains therein until in particular chlorine, alkali and lead compounds have almost completely evaporated out of the dust. Experience has shown this takes an hour. In that operation a scavenging gas flow is fed to the furnace atmosphere whereby the lead-chlorine-alkali vapour produced in the rotary cylindrical furnace is passed out of sane to a condensation and filtering apparatus.Reducing agent, in particular coal, is then introduced into the foundry dust and same is fed to a further furnace atmosphere which in particular is at 1150.degree. to 1350.degree. C., where it is continuously rolled around.