Ceramic spheroids having low density and high crush resistance
US4632876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Jun 12, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2998
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Ceramic spheroids having: PA0 A. a core made by firing raw materials comprising about: PA0 50-99.8 parts by weight mineral particulates; PA0 0.1 to 50 parts by weight silicon carbide; and PA0 0.1 to 15 parts by weight binder (e.g. bentonite); and PA0 B. an outer shell comprising Al.sub.2 O.sub.3 or MgO. More alumina or magnesium oxide is contained in the outer shell than in the core. The core of the ceramic spheroid has closed cell microporosity. The inventive spheroids are characterized by a density less than 2.2 g/cc and can be readily made to have a density less than 1 g/cc. These ceramic spheroids combine high strength (due to the tough outer shell) with low density (due to the closed cell microporosity) and have applications (among others) as buoyant water filtration media and low density fillers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.