Abstract: The anode effect which is necessary in the electrolytic cell can be extinguished after a short time if, immediately after it appears, fine granular salts are introduced together with an injection medium through a suitable channel into the electrolyte and under the anodes. These salts which are not harmful to the electrolytic process cause vigorous production of gases at the operating temperature of the cell. The channel for introducing the salts and the injection medium is usefully situated in the crust breaking chisel or a lance which can be lowered into the bath. The device comprises further a storage vessel for salts which has a closing facility which is activated via a closing piston, below that a combined measuring and injection chamber featuring an injection nozzle and a tube with by-pass connecting up to the injection chisel or lance.

Abstract: A cell for fused-salt electrolysis for reducing alumina in the presence of cryolite to metallic aluminum. The cell includes an insulated tank having a carbon bottom, two rows of anode rods disposed on opposite sides of an anode carrier positioned in the longitudinal center plane, an exhaust gas-collecting duct extending at the longitudinal center between the two rows of anode and covers downwardly inclined from the outside of respective rows of anode rods to respective edges of the tank and provided at the outer longitudinal edge and the transverse edges with a skirt that extends to the respective edge of the tank. Each cover is hinged adjacent to its longitudinal edge adjacent to the anodes and at least at its corner portions to a support which extends along the row of anode rods. A carrying arm is secured to each end portion of the support and is pivoted at its other end to the anode carrier.