发明名称 |
TRANSPARENTE ALUMINIUMOXID-MIKROKUGELN. |
摘要 |
Procedure for making Al2O3 spheroids, 600 micrometers in diameter or less, utilizes an AlOOH sol containing 0.25% weight percent MgO (in the form of Mg(NO3)2.6H2O3) and HNO;. The sol is dispersed into droplets in a particle forming fluid (e.g., 2-ethylhexanol) where gelling occurs. The gelled spheroids are collected, dried and pre-fired in air at temperatures less than 1,200 DEG C for up to about 12 hours. The dried and prefired beads are fired in a 2-step process at temperatures of about 1,850-1,950 DEG C in the following sequence: a first dry oxygen firing for about ten minutes, followed by a wet hydrogen firing for up to 350 minutes. Reasonably transparent microspheres having crystallites in the range of 5-100 micrometers are obtained with little intergranular porosity, and their density is estimated to be near theoretical. |
申请公布号 |
DE3869138(D1) |
申请公布日期 |
1992.04.23 |
申请号 |
DE19883869138 |
申请日期 |
1988.01.05 |
申请人 |
MINNESOTA MINING & MFG. CO., SAINT PAUL, MINN., US |
发明人 |
BESCUP, TERRANCE L. C/O MINNESOTA MINING AN;FELLOWS, BENJAMIN T. C/O MINNESOTA MINING AN;LEEDECKE, CHARLES J. C/O MINNESOTA MINING AND, P.O. BOX 33427 ST. PAUL MINNESOTA 55133, US |
分类号 |
C01F7/02;C01F7/36;E01F9/00;E01F9/04;G02B5/128 |
主分类号 |
C01F7/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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