GB511076A - Improvements in or relating to processes for the manufacture of anodes for use in the production of aluminium, beryllium, magnesium, or alkali earth metals by electrolysis of fused starting materials - Google Patents

Abstract

511,076. Anodes. GES. ZUR VERWERTUNG CHEMISCH TECHNISCHER VERFAHREN VADUZ. March 16, 1938, Nos. 8103 and 8104. Convention dates, March 16, 1937, and Jan. 17, 1938. [Class 41] Anodes for use in the production of aluminium, beryllium, magnesium or alkali earth metals by the electrolysis in the molten state of halogenous salts of the metal to be produced, which comprise an intimate mixture of carbon or carbonaceous material and an oxide of the metal to be produced, are made by intimately mixing tar or pitch or a mixture of tar and pitch with an oxide of the metal to be produced by electrolysis, subjecting the mixture of these ingredients to distillation protected from air to eliminate the volatile products, cooling and reducing to powder, and using the resulting powder as raw material for the manufacture of anodes by compressing and baking. The tar or pitch may be replaced in part by a mixture of carbon powder and tar and/or pitch, and the carbonaceous material may be added in a plurality of stages, the mixture being each time heated protected from air and finely crushed. At any stage in the manufacture of the anodes, one of the following bodies may be added as catalysts to facilitate the reaction between the oxide of the metal, the carbon, and the halogen produced at the anode during electrolysis :-iron as metal, oxide, sulphide, or carbonate, or nickel, manganese, molybdenum or compounds thereof. The anodes, after forming or moulding, may be baked in the electrolytic furnace itself during electrolysis in any manner known per se, and may be provided with a metal supporting casing constituted by one of the above catalysts, e.g. iron. The proportion of carbon in each anode should be of the order of 15 to 25 per cent. the precise proportion of carbon being dependent on the particular case treated. The connection serving for the admission of electric current may consist of rods arranged laterally relatively to the anode and penetrating within the latter. The metallic oxides used may contain small proportions of compounds such as hydroxides or carbonates which are converted to oxide during baking and electrolysis. In cases where the oxide used requires only a small proportion of carbon, the oxide can be mixed and kneaded with the pitch and/or tar in the hot state and directly shaped in the form of an anode and baked.