| 摘要 |
PURPOSE:To reduce the elution quantity of aluminum ions in waste water without damaing catalyst performance by adjusting pH of reaction liquid in the specified range without cooling after completion of aging. CONSTITUTION:Aging is continued for 1-3 hours while maintaining pH at 9.5-13 and at the sedimentation reaction temperature of 60-150 deg.C to complete the sedimentation reaction. After that, while the temperature range of 60-150 deg.C is maintained, acid such as sulfuric acid, hydrochloric acid or its water solution is dropped into slurry containing sediments of respective aged catalyst components and its pH is adjusted to 5-9. Then, sediments are separated, washed and dried, and the dried substance is burnt to manufacture a catalyst. When pH is adjusted to 5-9, excessive aluminum ions existing in the filtrate are sedimented on the surface of catalyst and not remaining in the filtrate. A catalyst of high activity can easily be manufactured without the necessity of troublesome draining process after manufacturing of catalyst by said process. |
