Electrode assemblies and mutimonopolar cells for aluminium electrowinning
US5368702A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 25, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | May 25, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C3/08
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A multimonopolar cell for electrowinning aluminium by the electrolysis of alumina dissolved in a molten salt electrolyte, comprises electrode assemblies each having a non-consumable anode and a non-consumable cathode both resistant to attack by the electrolyte and by the respective product of electrolysis. The anode (2) is preferably of tubular form with an active anode surface (7) inside, and the cathode is made of one or more rods (1) or tubes placed in the middle of the tubular anode or between plate anodes, the cathode extending beyond the bottom of the anode. The active anode surface area is bigger than the facing active cathode surface area. In use, the electrode assembly is partly immersed vertically or at a slope in the electrolyte (3) with the cathode dipping in a layer (4) of aluminum on the cell bottom. Liquid aluminium formed during electrolysis on the cathode surface drips or downflows to the bottom of the cell and oxygen evolved at the anode surface rises through the electrolyte and escapes at the top of the tubular anode. Current supply to the cathode rods is preferably through the cell bottom and the layer (4) of aluminium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.