| 摘要 |
A method of preparing spheroidal alumina particles of improved physical stability is disclosed. Alumina hydrogel particles prepared by the oil-drop method are aged in the forming oil at atmospheric pressure conditions and at a temperature of from about 95 DEG to 105 DEG C. until the hydrogel spheres achieve a pH in excess of 6 to about 7.5. The forming oil is thereafter displaced with an ammonium salt-buffered aqueous ammoniacal solution, and the hydrogel spheres aged therein for a brief period. After further aging in an aqueous ammoniacal solution in accordance with prior art practice, the spheres are water-washed, dried and calcined.
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