Abstract: A method of treating a carbonaceous cell component of an electrolyte cell for the production of aluminum, to impart protection against deterioration during operation of the cell. A liquid suspension of a refractory material dispersed in a lignosulfonate binder solution is prepared and applied as a protective coating to the surface of carbonaceous cell components and allowed to dry.

Abstract: A refractory coating is provided for a component of an electrolytic cell for the production of aluminum in which an aqueous slurry is prepared comprising particulate refractory material, e.g. TiB2, dispersed in an aluminum oxalate complex. The slurry is applied as a coating to the surface of the component, e.g. a cathode block, and dried to form a hard refractory surface on the component. The aluminum oxalate complex may be formed in situ during production of the slurry by mixing together oxalic acid and electrostatic precipitator dust comprising aluminum oxide. After the refractory coated component is immersed in a high temperature cryolite bath of an aluminum electrolysis cell, the aluminum oxalate complex is converted to alumina which bonds the refractory particles to the surface of the cell component.

Abstract: A method of treating a carbonaceous cell component of an electrolyte cell for the production of aluminum, to impart protection against deterioration during operation of the cell. A liquid suspension of a refractory material dispersed in a lignosulfonate binder solution is prepared and applied as a protective coating to the surface of carbonaceous cell components and allowed to dry.

Abstract: A process of producing multi-layer cathode structures. In one aspect, the process comprises providing a carbonaceous cathode substrate, and forming at least one layer of a metal boride-containing composite refractory material over the substrate, wherein the surface of the carbonaceous substrate to be coated is roughened prior to the formation of the layer overlying the said surface. The roughening of the surfaces reduces the tendency of the layers to separate in high temperature operating conditions. In another aspect, the process comprises providing a carbonaceous cathode substrate, and forming at least two coating layers of a metal boride-containing composite refractory material successively over the substrate, wherein the content of metal boride in the coating layers increases progressively as the distance of the layer from the substrate increases.