Method for producing ceramic particles and agglomerates
US6261484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 2000 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Aug 11, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/61
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for generating spherical and irregularly shaped dense particles of ceramic oxides having a controlled particle size and particle size distribution. An aerosol containing precursor particles of oxide ceramics is directed into a plasma. As the particles flow through the hot zone of the plasma, they melt, collide, and join to form larger particles. If these larger particles remain in the hot zone, they continue melting and acquire a spherical shape that is retained after they exit the hot zone, cool down, and solidify. If they exit the hot zone before melting completely, their irregular shape persists and agglomerates are produced. The size and size distribution of the dense product particles can be controlled by adjusting several parameters, the most important in the case of powder precursors appears to be the density of powder in the aerosol stream that enters the plasma hot zone. This suggests that particle collision rate is responsible for determining ultimate size of the resulting sphere or agglomerate. Other parameters, particularly the gas flow rates and the microwave power, are also adjusted to control the particle size distribution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.