GB930832A - Improvements in or relating to electrolytic cells for the production of aluminium - Google Patents

Abstract

930,832. Electrolytic apparatus. BRITISH ALUMINIUM CO. Ltd. June 22, 1959 [June 24, 1958], No. 8522/63. Divided out of 930,831. Drawings to Specification. Class 41. An electrolytic cell for the production of aluminium comprises a chamber having walls composed of a silicon carbide refractory material and a floor of a refractory material, the chamber being intended to contain a pool of molten aluminium in the lower part thereof and a body of electrolyte above and in contact with the molten aluminium, and at least one cathodic current-conducting element extending into said lower part of the chamber and having at least that part of the surface thereof intended to contact the molten aluminium consisting essentially of a refractory hard metal. The expression " refractory hard metal " is defined as a material which possesses a low electrical resistivity, a low solubility in molten aluminium and molten electrolyte under cell operating conditions, a good stability under conditions existing at the cathode of a reduction cell, and which is wettable by molten aluminium under cell operating conditions. Preferred examples are the carbides and borides of titanium, zirconium, tantalum and niobium, and mixtures thereof. The cells may comprise a metal, e.g. steel, shell within which is an insulating lining of alumina, bauxite, clay or aluminium silicate bricks within which is the refractory lining of silicon carbide or silicon nitrite-bonded silicon carbide. Alternatively, the side and end walls can be constructed of silicon carbide bricks and the floor of rammed carbon mixture. The subject-matter of Specification 930,831 is disclaimed. Reference has been directed by the Comptroller to Specification 802,905.