GB815076A - Improvements relating to the production of aluminium by fused salt electrolysis - Google Patents

Abstract

815,076. Fused electrolyte cells. MONTECATINI SOC. GENERALE PER L'INDUSTRIA MINERARIA E CHIMICA, and VARDA, G. DE. July 24,1956 [July 28, 1955], No. 22850/56. Class 41. A furnace for producing aluminium by fused salt electrolysis has at least one electrolytic cell having a vertical or inclined carbon cathode wall 21 the surface 1<SP>1</SP> of which is cellular, Fig. 3, or formed with a number of receptacles 3, Fig. 9, or 31, Fig. 10, adapted to retain molten aluminium 4. By the term carbon is meant any carbonaceous material, including graphite. The receptacles 3, 3<SP>1</SP> may be elongated, Fig. 10, or may have circular entrances, and in the case of an inclined cathode, may be stepped rearwardly, Fig. 9. The face 1<SP>1</SP> of the cathode may have an inert, insulating coating 12<SP>1</SP>, e.g. of electro-fused aluminium oxide or magnesium oxide, and the coating 12<SP>1</SP> may extend along the upper walls of the receptacles 3<SP>1</SP>. The general construction of the cell may be as described in Specification 814,754, and pre-baked or self-baking anodes may be employed. In starting the cell, molten aluminium is introduced into the receptacles 3, 3<SP>1</SP>, and during operation alumina is fed to the cell at a point remote from the cathode or dissolved in the bath e.g. in powder form or dissolved in the bath. The molten aluminium 4 in the receptacles 3, 3<SP>1</SP> and in the cellular surface 1<SP>1</SP> localizes the interaction between the electrolyte and the cathode and helps to protect the cathode surface. Specifications 800,092 and 802,959 also are referred to.