Refractory material for electrolytic cells, method for the manufacture and use of the refractory material

Abstract From the Canadian patent

The invention relates to a material which is refractory porous, resistant to fluorine-containing gases stable in its volume and, heat-insulation particularly in the form of formed bricks for a refractory, heat-insulating lining in electrolytic cells in which metal aluminum is extracted, by electrolysis from aluminum oxide dissolved in a fluoride melt; the material has an Al2O3 content of over 50 wt% and a TiO2 content of 2.5-10 wt% and during the action of fluorine-containing gases at temperatures between 700 and 1000°C in the area of the material exposed to the fluorine gas, on free surfaces, particularly at the boundary surfaces of intergranular hollow spaces, needle-shaped TiO2 crystals …