Process for recovering aluminum and other metal values from fly ash
US4159310A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1978 |
| Grant date | Jun 26, 1979 |
| Priority date | — |
| Expiry date | Jan 30, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for recovering aluminum from fly ash containing iron, silicon and titanium which comprises: (a) chlorinating the fly ash in an oxidizing atmosphere to selectively chlorinate and vaporize iron chloride from the remaining chlorides, (b) chlorinating the residue from step (a) in a reducing atmosphere of carbon monoxide, in the presence of added silicon chloride to suppress the chlorination of silicon, and vaporizing the chlorides of aluminum, silicon, titanium, and the residual iron, (c) separating and recovering the vaporized chlorides by selective condensation, and treating the residue of step (b) with sulfuric acid to convert calcium chloride to gypsum, and to regenerate a chloridizing and binder solution for pelletizing fly ash feed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.