Method of obtaining pure alumina by acid attack on aluminous minerals containing other elements
US4124680A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1978 |
| Grant date | Nov 7, 1978 |
| Priority date | — |
| Expiry date | Feb 9, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F7/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of obtaining alumina of high purity from aluminous mineral containing impurities in which the mineral is attacked with a sulphuric acid liquor followed by separation of a liquid phase from the resulting solid residue comprising PA1 (1) mixing the liquid phase with a liquor containing HCl and H.sub.2 SO.sub.4 at elevated temperature, PA1 (2) cooling the mixture with the precipitation of hydrated aluminum chlorosulphate having the formula AlSO.sub.4 Cl.6- 7H.sub. 2 O, PA1 (3) separating the precipitate from the remaining liquor which contains the major part of the impurities in solution, PA1 (4) suspending the separated precipitate in a hydrochloric acid liquor, PA1 (5) chlorinating the suspension by introduction of gaseous HCl with precipitation of AlCl.sub.3.6H.sub. 2 O, PA1 (6) separating the precipitated AlCl.sub.3.6H.sub. 2 O, and PA1 (7) pyrolizing the separated precipitate to produce alumina of high purity and gaseous HCl.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.