Combination for electrolytic reduction of alumina
US6379512B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2000 |
| Grant date | Apr 30, 2002 |
| Priority date | — |
| Expiry date | Nov 25, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C3/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises molten electrolyte having the following ingredients: AlF3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound is, a fluoride; oxide, or carbonate. The metal is nickel, iron, copper, cobalt, or molybdenum. The bath is employed in a combination including a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the instant bath during electrolytic reduction of alumina to aluminum improves the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.