Cathodes for alumina reduction cells

US4333813A · kind A · utility

Assignee

• Reynolds Metals Company · US

Inventors

• Howard I. Kaplan · Florence, US
• Jerry H. Bryce · Lawrenceburg, US
• Thomas J. Johnston · Pittsford, US
• Curtis J. McMinn · Florence, US
• John T. Willett · Florence, US
• Nolan E. Richards · Florence, US

Key dates

• Filing date: Nov 5, 1980
• Grant date: Jun 8, 1982
• Expiry date: Nov 5, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/30
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

This invention concerns cathodes for alumina reduction cells, particularly drained cathodes, which present a refractory surface for contacting molten aluminum on the cell floor. This invention also concerns materials for constructing such cathodes. The cathodes described comprise a carbonaceous bed, preferably a graphite bed, and a composite tile. This tile is characterized by a layer of a refractory hard metal (RHM) material bonded to a base layer of a graphitic material, where the RHM layer comprises a hot pressed mixture of titanium diboride and aluminum nitride powders. The tile is further characterized by the bond between the RHM layer and the graphitic base layer, such bond having been produced simultaneously as the RHM layer is formed by hot pressing the mixture of titanium diboride and aluminum nitride powders directly against the graphitic base layer. The graphitic base layer is in turn bonded to the carbonaceous bed by means of a carbonaceous cement, and the RHM layer thereby provides a refractory surface for contacting molten aluminum.