Abstract: Dusts containing zinc and/or lead in the form of oxides and one or more reducing agents are mixed with each other before or after being introduced into a heat treatment furnace. The mixture is heated to a given temperature range under a substantial vacuum so that the zinc and/or lead in the form of oxides are reduced to zinc and/or lead in the state of pure metals and evaporated in the furnace. The evaporated zinc and/or lead are introduced into a retrieving container also under a substantial vacuum and at a given temperature where the evaporated zinc and/or lead pure metals are condensed and retrieved.

Abstract: Metal plated steel sheet scraps are heated to a temperature in the range of about 200.degree. C.-500.degree. C. so that organic material adhered to the scraps is evaporated and removed. Then, the scraps from which organic material has been removed are heated to a temperature in the range of about 500.degree. C.-950.degree. C. so that the plated metal, for example zinc or aluminum, is evaporated. The evaporated metal flows to a retrieving device where the evaporated metal is condensed and retrieved.