摘要 |
A spinel containing slip-casting composition, method for preparing the spinel slip-casting composition and method for casting the slip into usable forms are described. The spinel employed to prepare the castable slips is a pre-calcined spinel and a calcined spinel each prepared in the manner of copending application Ser. No. 184,189, filed Sept. 4, 1980, which is ball-milled with water, then mixed with a deflocculant at pH 9 or below. The slurry or "slip" is cast into a mold porous to water until the desired thickness of solid has been obtained and the excess "slip" decanted or otherwise withdrawn from the mold. The green shape is retained in the mold until it gains green strength, 1 hour to 5 days, and thereafter placed in an oven wherein it is fired to above about 1400 DEG C. for from 1 to 20 hours until it has reached its maximum density of between about 50 and 99 percent of theoretical.
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