Patent ID: 7776126

Claim:
A method of continuously processing at least one of a molten metal product, a vapor phase metal product and a slag product from at least one waste material which comprises: providing a furnace containing a molten metal bath and having a headspace above the molten metal bath and opposite ends; operating the furnace so that the surface of the molten metal bath is not under turbulent conditions; feeding at least one waste material into the furnace at one of the opposite ends and into a slag layer that floats on the molten metal bath so that the waste material is engulfed by the slag layer; allowing the at least one waste material to react in the furnace to replenish the slag layer that floats on the molten metal bath and produce and release volatile components therefrom and carbon monoxide into the headspace of the furnace; removing a portion of the slag layer as a slag product from another one of the opposite ends so as to cause the slag layer and the at least one waste material fed into the slag layer to move across the surface of the molten metal bath; continuously maintaining the thickness of the slag layer at a level so that the thickness is sufficient to support the at least one waste material in the slag layer; and continuously controlling an amount of ambient air that enters into the headspace of the furnace by controlling a vacuum applied to the headspace so as to maintain a reducing atmosphere in the headspace while combusting a portion of the carbon monoxide to heat the headspace.