Process for preparing spheroidal alumina particles
US4179408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1977 |
| Grant date | Dec 18, 1979 |
| Priority date | — |
| Expiry date | Mar 25, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S502/503
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Spheroidal alumina particles have a combination of high macroporosity, surface area, crush strength and low attrition loss and bulk density. The particles are prepared by an improved external gelation oil-drop process. In the process a slurry of alumina, preferably a microcrystalline boehmite-pseudoboehmite intermediate, is prepared in an acidic aqueous medium and droplets of the slurry are passed through air into a column containing an upper body of water-immiscible liquid and ammonia and a lower body of aqueous coagulating agent. Catalysts employing the particles as a support and having catalytic agents distributed at controlled depths in the particle have excellent initial and sustained activity and durability, especially for eliminating pollutants in automotive exhaust streams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.