Method and reactor for production of aluminum by carbothermic reduction of alumina
AssigneesAlcoa Inc., Elkem ASA
InventorsJan Arthur Aune, Kai Johansen
Life of this patent
Estimating the term…
Abstract
A hollow partition wall is employed to feed carbon material to an underflow of a carbothermic reduction furnace used to make aluminum. The partition wall divides a low temperature reaction zone where aluminum oxide is reacted with carbon to form aluminum carbide and a high temperature reaction zone where the aluminum carbide and remaining aluminum oxide are reacted to form aluminum and carbon monoxide.
Claims20
A process for carbothermic production of aluminum where a molten bath comprising aluminum carbide is produced in a low temperature compartment, which molten bath flows into a high temperature compartment where the aluminum carbide is reacted with alumina to produce aluminum which forms a layer above a molten slag;
- wherein the low temperature compartment and the high temperature compartment are located in a common reaction vessel and the low temperature compartment is separated from the high temperature compartment by a hollow underflow partition wall having an opening in the wall;
- the molten bath produced in the low temperature compartment continuously flows under the partition wall and into the high temperature compartment, and where additional carbon material is supplied to the flow under the partition wall through the opening in the hollow partition wall.
A reactor for carbothermic production of aluminum, comprising a reaction vessel comprising a low temperature reaction compartment having means for supply of materials to said compartment and one or more electrodes for supplying electric operating current to said compartment, said electrode or electrodes being positioned for submersion in a molten bath in the low temperature compartment;
- a high temperature compartment separated from the low temperature compartment by means of a hollow partition wall allowing underflow of molten bath from the low temperature reaction compartment into the high temperature compartment, said wall having an opening and a transport means feeding additional carbon material to the underflow through the opening in the hollow partition wall;
- electrodes arranged in a sidewall of the high temperature compartment of the reaction vessel for supply of electric current to said compartment;
- means for injecting material into the high temperature compartment;
- and
- an outlet for continuously tapping molten aluminum from the high temperature compartment.
In a reactor for producing aluminum by carbothermic reduction of alumina having a single reactor with two compartments, a high temperature reaction compartment and a low temperature reaction compartment, and an underflow partition wall that separates the two compartments where slag flows under the partition wall from the low temperature compartment to the high temperature compartment, the improvement comprising:
- a supply means for supplying additional carbon material through the underflow partition wall to the slag flowing from the low temperature compartment to the high temperature compartment.
Dependencies are inferred from the claim text.