Method for producing anhydrous alumina
US4529579A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1984 |
| Grant date | Jul 16, 1985 |
| Priority date | — |
| Expiry date | Jun 28, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to a method for the production of anhydrous alumina having a desired .alpha.-conversion from alumina trihydrate. This method is directed to production of anhydrous alumina having a desired .alpha.-conversion from alumina trihydrate in which water is removed in a precalcining zone wherein the alumina trihydrate is heated to a temperature below 450.degree. C. Then, the precalcined dehydrated alumina is recrystallized to .alpha.-alumina in a reaction chamber by directing an oxygen containing gas to the reaction chamber, mixing and suspending the precalcined alumina and fuel in the oxygen containing gas and feeding the mixture to a combustion zone, followed by exothermal recrystallization of the alumina which is initiated by rapidly heating the precalcined alumina by burning the fuel in the oxygen containing gas in the hot combustion zone and withdrawing the recrystallized alumina from the top of the reaction chamber suspended in a combustion gas stream. The recrystallized alumina is then separated from the gas stream and cooled to produce anhydrous alumina having the desired content of .alpha.-conversion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.