Dissolution of the oxide catalìtica alumìnio during the reduction eletrolìtica alumina

摘要

b dissolution catalu00ectica alumu00ecnio oxide during reduction eletrolu00ectica alumina d electrolytic bath for use during electrolytic reduction of alumina to aluminum.The bath comprises a molten electrolyte having the following ingredients: (a) ALF ~ 3 ~ and at least a salt selected from the group consisting of NaF, KF and LIF; and (b) (I) of approximately 0.004% by weight to about 0.2% by weight based on the total weight of the molten electrolyte, and at least a transition metal or at least one compound of the metal or both.And / or (II) metallic aluminum. The compound can be, for example, a fluoride, oxide or carbonate. The metal can be nickel, iron, copper, cobalt or molybdenum.The bath may be employed in a combination that includes a container to contain the bath and at least one non consumable anode and at least one dimensionally stable cathode in the bath.Using the bath of the present invention during electrolytic reduction of alumina to aluminum can improve the wetting of a cathode with aluminium by reducing or eliminating the formation of depu00f3sitThe non metal on the cathode.The removal of the sulfur from the bath before the electrolytic reduction or prior to passing a current through the bath can also minimize the deposits on the cathode.The aluminum formed in the cathode can be removed directly from the cathode.