Patent ID: 7556667

Claim:
A batch carbothermic method of producing low carbon aluminum, the method comprising: (a) producing a first mixture in a single furnace reactor having a single reactor compartment and a plurality of resistance heating electrodes, wherein the first mixture comprises slag and solid aluminum carbide; (b) forming in the single furnace reactor an upper Al—C alloy phase and a lower slag phase from the first mixture; (c) extracting carbon from the upper Al—C alloy phase into the lower slag phase via addition of aluminum oxide to the single furnace reactor; (d) removing at least a portion of the upper Al—C alloy phase from the single furnace reactor; (e) collecting, during at least one of the producing and forming steps, off-gas from the single furnace reactor in an external vapor recovery reactor, the off-gas comprising at least one vapor species of Al 2 O, Al and CO; (f) adding, concomitant to the collecting step, a carbonaceous material to the external vapor recovery reactor, thereby forming a recyclable material, the recyclable material comprising Al 4 C 3 , and wherein the producing step comprises: (g) feeding the recyclable material from the vapor recovery reactor to the single furnace reactor to assist in the production of the first mixture.