Technique for automatic quenching of anode effects in aluminium reduction cells
AssigneeAlcan Research and Development Limited
InventorsAnthony M. Archer, Edward L. Cambridge, Douglas F. Hewgill
Life of this patent
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Abstract
For the clearance of anode effects in operation of electrolytic cells for aluminium production, movement in the metal pool is induced to effect short-circuiting of the cell and disturbance of any gas film on the face of the anode(s) by raising the anode(s) and then lowering them to datum position and/or tilting the anode in relation to datum position. Upward movement is terminated either after a predetermined distance or when a predetermined cell voltage is attained. Fresh alumina is introduced into the cell by breaking alumina crust by anode movement or by independent supply.
Claims10
A method of clearing anode effects in the operation of an electrolytic reduction cell for the production of aluminium by the electrolysis of alumina in a molten fluoride bath which comprises raising the anode or anodes from a datum position by a predetermined distance or until a predetermined high cell voltage is established and lowering the said anode or anodes, such raising and lowering being performed in such manner that short circuiting between said anode or anodes and the pool of molten aluminium in the bottom of the cell takes place during such anode movement as the result of local upward movement of said molten metal due to electromagnetic effects, fresh alumina being added to said molten fluoride bath in conjunction with movement of said anode or anodes of said cell.
A method of clearing anode effects in the operation of an electrolytic reduction cell for the production of aluminium by the electrolysis of alumina in a molten fluoride bath which comprises tilting the anode or anodes from a datum position, without lowering the mass of said anode or anodes, in such manner that short circuiting between the anode or anodes and the pool of molten aluminium in the bottom of the cell takes place, the anode or anodes then being returned to said datum position, fresh alumina being added to said molten fluoride bath in conjunction with the movement of said anode or anodes of said cell.
Dependencies are inferred from the claim text.