Slag decarbonization with a phase inversion
US4409021A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1982 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | May 6, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22B21/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A batch method is described for decarbonizing aluminum primary furnace product from an aluminum carbide content of up to about 35% to a useful content of about 2% Al.sub.4 C.sub.3. The method maximizes mass transfer of the aluminum carbide from molten primary furnace product to molten slag and molten alumina in a decarbonization furnace which has elevatable electrodes and is operated in the extraction mode according to the equation: EQU Al.sub.4 C.sub.3 +4Al.sub.2 O.sub.3 .fwdarw.Al.sub.4 O.sub.4 C. The method comprises forming an overlying molten layer of primary furnace product, preferably as an aluminum alloy containing 9.5% Al.sub.4 C.sub.3 and 12% Al.sub.2 O.sub.3 and at a temperature of about 2100.degree. C., and an underlying molten layer of slag, at a temperature of about 1900.degree. C., and then adding an alumina cover layer of granular alumina onto the overlying layer of alloy melt. The method further comprises mechanically stoking the cover layer, while melting the alumina with the electrodes, to create globules of melted alumina within the overlying layer as a two-phase region having a plurality of interfaces across which the extraction principally occurs. As extractio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.