| 摘要 |
Beads are produced from crystalline peptisable Al2O3.H2O by granulation with spraying with aqs. soln. of mineral acid and/or its salt, ageing and calcination. Peptising after-treatment is followed by compression and moderate drying of granules until water content is reduced from is not 47% to 42-46, pref. 43-45.5% then dehydration to 1 - 10, pref. 6 - 9% residual water content in hot gas stream at 35 - 850, pref. 380 - 550 degrees C, pref. in fluidised bed. The beads have high specific surface area and attrition resistance. - Raw material used is cheap, whilst product combines high mechanical strength with high water absorption capacity. Process avoids certain technical difficulties, e.g. corrosion, strong acid vapour and double dehydration with intermediate milling.
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