| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a silica gel to easily manufacture a silica gel of high purity by using wastes. SOLUTION: Incineration ash obtained by burning chaffs of grains such as rice chaff is mixed and stirred with a strong alkali aqueous solution containing an alkali metal compound such as sodium carbonate to prepare a liquid mixture. The liquid mixture is heated at 80 to 100°C and subjected to solid liquid separation to separate a filtrate from the ash. The ash is steamed with hydrochloric acid to obtain activated carbon as a byproduct. The filtrate is rapidly cooled for solid liquid separation and the solid content is mixed and stirred with an acid, heated at 100°C and the solid is separated from the liquid. The solid is washed with water and dried to obtain a silica gel of high purity. Thus, the silica gel of high purity can be manufactured at a low cost in easy processes by using chaffs of grains containing a lot of silica, which are generated in a large amount as wastes. COPYRIGHT: (C)2003,JPO
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