Refractory material

US5322826A · kind A · utility

Assignee

• Dr. C. Otto Feuerfest GmbH · DE

Inventors

• Wolfgang Becker · Eppstein, DE
• Fred Brunk · Hattingen, DE

Key dates

• Filing date: May 29, 1992
• Grant date: Jun 21, 1994
• Expiry date: May 29, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/25
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

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 Al.sub.2 O.sub.3 content of over 50 wt % and a TiO.sub.2 content of 2.5-10 wt % and during the action of fluorine-containing gases at temperatures between 700.degree. and 1000.degree. 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 TiO.sub.2 crystals and/or TiO.sub.2 -containing crystals are formed, growing without regularity into the porous space. The invention furthermore relates to a method for the manufacture as well as the use of the refractory material.