Thermally stable ceramic media for use in high temperature environments
AssigneeSaint-Gobain Ceramics & Plastics, Inc.
InventorJohn Reid
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Abstract
A chemical processing apparatus that utilizes a ceramic media sintered at a lower temperature than the apparatus' maximum exposure temperature is described. The media's physical and chemical properties may contribute to its thermal stability when exposed to temperatures that exceed the media's sintering temperature by at least 50° C.
Claims42
Ceramic media, comprising:
- (a) MgO, wherein said MgO is between 48 and 78 percent by weight of said media;
- (b) SiO2, wherein said SiO2 is between 5 and 30 percent by weight of said media;
- (c) Al2O3, wherein said Al2O3 is between 5 and 30 percent by weight of said media;
- and
- (d) wherein said media is between 24 percent and 38 percent porous based on the apparent volume of the media and said media's major phase, as determined by x-ray diffraction analysis, is MgO.
A process for manufacturing ceramic media, comprising:
- (a) providing a mixture of raw materials comprising magnesium oxide, ball clay, bentonite and feldspar wherein said magnesium oxide is in particulate form and at least 45 weight percent of said particles are between 30 and 250 microns;
- (b) forming said mixture into a plurality of three dimensional media;
- and
- (c) heating said media to a sintering temperature greater than 1200° C. and less than 1250° C.;
- wherein said sintered media has a porosity greater than 24 percent and less than 38 percent based on the apparent volume of the media and said media's major phase, as determined by x-ray diffraction analysis, is MgO.
Ceramic media having a first volume, which corresponds to the apparent volume of the media at 22° C. after heating the media to at least 1200° C. but prior to heating the media above 1250° C., and a second volume, which corresponds to the apparent volume of the media at 22° C. after heating the media to at least 1300° C. but less than 1500° C., wherein the ratio of said second volume to said first volume is between 0.9:1 and 1:1.
A chemical processing apparatus comprising a plurality of ceramic media formed at a sintering temperature, said media are physically distinct and readily separable from one another after thermal cycling in the apparatus from a first temperature that is less than the media's sintering temperature to a second temperature which is at least 50° C. higher than the media's sintering temperature and then back to the first temperature.
Dependencies are inferred from the claim text.