COATING COMPOSITION FOR A CARBONACEOUS MATERIAL, AND RESULTING COATING

摘要

A composition for a protective coating on the surface of carbonaceous materials exposed to a hot oxidising medium, e.g. the portions of anodes and edge slabs that are not immersed in the molten salt bath of an aluminium electrolytic cell, and generally the non-immersed portions of carbonaceous refractory elements used in electrolysis performed at under 950 DEG C in a molten salt bath. The composition comprises a geopolymer, preferably from the fluoro-poly(sialate-disiloxo) family, and its other components are optionally water as well as alumina and/or another refractory such as silica. A coating is also provided for protecting the surface of carbonaceous materials exposed to a hot oxidising medium, e.g. the non-immersed portions of carbonaceous refractory elements used in electrolysis performed at under 950 DEG C in a molten salt bath. Said coating comprises polysilicates and at least one inorganic polymer from the poly(sialate) family, preferably the fluoro-poly(sialate-disiloxo) family, and optionally alumina or another refractory such as silica. An aluminium electrolytic cell anode provided with said coating is also disclosed.