Method of removal of light metals from aluminum
US6375712B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Dec 29, 1998 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Dec 29, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22B21/064
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Improved apparatus and method are described for the removal of light metals; sodium, lithium, calcium and magnesium, from virgin aluminum tapped from a Hall Heroult reduction cell using LiF-modified or LiF+MgF2 electrolyte. The method is performed in a crucible or at a station intermediate between the cells and furnaces in a cast house. Fine particulate aluminum fluoride and/or sodium aluminum tetrafluoride are transported by a gas or gas mixture into the molten aluminum in a manner such that the light metals are preferentially removed or their concentration substantially lowered through:a) the axle of a specially designed spinning impeller;b) partially through the axle of a specially designed spinning impeller and partially through one or more pipes equipped with dispersers for dispersing into the molten metal flow close to the spinning impeller; orc) through one or more pipes equipped with dispersers for dispersing into the molten metal flow close to the impeller fastened to a solid axle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.