Verfahren und Anlage zum Schmelzen verunreinigter metallischer Abfälle.

摘要

A process and apparatus for melting contaminated metalliferous scrap material are disclosed. The process comprises introducing the contaminated material (11, 72) into a melting furnace (12, 70), heating the material by means of a plasma (13, 71) at a temperature below the melting point of the metal at which the non-metallic contaminants are volatilized in an atmosphere which is preferably inert or has low reactivity with the metal under the process conditions while displacing at least some of the material (11, 72) within the furnace interior, withdrawing volatile contaminants from the furnace (12, 70), increasing the temperature in the furnace preferably while maintaining an atmosphere of low reactivity in the furnace in order to melt the metal while preferably displacing at least some of the material in the furnace interior, and removing molten metal (77) from the furnace. The process allows scrap material to be melted with good metal recovery without the need for separate decontaminating apparatus. The process can also avoid the need to shred the scrap and to add large amounts of fluxing salts to separate the molten metal from remaining dross. A rotary furnace (12, 70) heated by means of a contained arc plasma torch (13, 71) is preferably employed in the apparatus which also preferably comprises an incinerator (21, 79) for oxidizing the volatile contaminants withdrawn from the furnace.