Cathode pot of an aluminum reduction cell
AssigneeSwiss Aluminium Ltd.
InventorsMax Zollinger, Raoul Jemec
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Abstract
A fused salt reduction cell for producing aluminum comprises a cathode pot having an outer steel shell supported on or by metal structural parts, a thermally insulating layer and an inner lining which is of carbon, is electrically conductive and is resistant to attack by the molten aluminum and the electrolyte. In the region of the electrolyte there is a layer which runs horizontally around the cell dividing the carbon lining into a lower part and an upper part. This layer is of a material which is resistant to the electrolyte at temperatures up to 1000.degree. C. and has a much lower shear strength than that of the carbon lining.
Claims17
A cathode pot of a fused salt reduction cell comprising an outer steel shell, a thermally insulating layer and an inner lining made of carbon, the improvement comprising a low shear strength electrolyte resistant layer which runs horizontally around the cell and exclusively arranged at the level of the electrolyte to which it is resistant for dividing the carbon lining into a lower part and an upper part such that the electric field in the cell runs through the lower part of said carbon lining thereby resulting in swelling of the lower part of said carbon lining to a greater degree than said upper part of the carbon lining wherein the resultant stresses due to the swelling are accommodated by the fracturing of said low shear strength elctrolyte resistant layer wherein said layer is formed of a material characterized by the ability to withstand temperatures up to 1000.degree. C. and a shear strength significantly lower than that of the carbon lining.
Dependencies are inferred from the claim text.