Novel process for the preparation of high purity alumina from ammonium alum
US4377566A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1981 |
| Grant date | Mar 22, 1983 |
| Priority date | — |
| Expiry date | Jun 29, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/13
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Process for preparing high purity aluminas from ammonium alum, the process comprising separately dehydrating the alum and thereafter thermally decomposing the dehydrate, wherein the thermal decomposition is carried out by forcing a gas through a layer of the dehydrated alum so as to continuously remove the gaseous reaction products formed without removal of solids by the carrier gas, and providing improved productivity of high purity transition aluminas having specific surfaces above 125 m.sup.2 /g and/or bulk densities above 0.2 g/cm.sup.3, the transition aluminas so obtained being characterized by their greater reactivity for the preparation of corundum so that corundum having a bulk density greater than 0.4 g/cm.sup.3 can be economically prepared.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.