Treatment of gases from a carbothermic reactor for the production of aluminum

Abstract From the Canadian patent

In the production of aluminium by the carbothermic reduction of alumina the evolved CO gas laden with Al and Al2O fume, is contacted with gaseous chlorine at a location within the carbothermic reduction furnace or at or near the gas outlet from the furnace and before the evolved gas has undergone significant cooling. The amount of chlorine employed is preferably in excess of the requirement for conversion of all the fume content to AlCl3. Further quantities of AlCl3 may be generated by injecting alumina and chlorine into the CO gas stream at a carbochlorination reactor downstream from the reduction furnace.