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: The magnitude of the horizontal components of electrical current flowing through the aluminium on the cathode blocks of an electrolytic reduction cell are reduced by ensuring that the current transmitted decreases towards the edge of the electrolytic cell. This is achieved by making the contact resistance between the carbon lining and the cathode bars embedded in the carbon cathode blocks increase towards the edge of the cell. The result is that the tendency for the melt to bulge upwards and the stirring action in the electrolyte are considerably reduced.