Treated carbon cathodes for aluminum production, the process of making thereof and the process of using thereof

US5378327A · kind A · utility

Assignee

• Moltech Invent S.A. · LU

Inventors

• J. A. Sekhar · Cincinnati, US
• T. Zheng, deceased · Centerville, US
• J. J. Duruz · Geneva, CH

Key dates

• Filing date: May 2, 1994
• Grant date: Jan 3, 1995
• Expiry date: May 2, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25C3/08
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

To improve its resistance to penetration and degradation by sodium, a carbon cathode for use in aluminium production by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte is pre-treated with a solution, suspension or melt of a compound of lithium, sodium and/or potassium. This pre-treatment takes place prior to, during or after forming the cathode but before use thereof. The entire carbon cathode, or only that part of the carbon which is nearest to the active cathode surface is treated, making it more resistant to penetration by components of the molten electrolyte of aluminium.