摘要 |
A method for production of a silica gel which comprises burning the husk of a grain to provide a burned ash, charging the burned ash in an strongly alkaline aqueous solution containing an alkali metal compound, followed by agitating, to prepare a liquid mixture, heating the mixture and then separating the mixture into an ash and a filtrate, steaming the ash with hydrochloric acid to produce an activated carbon as a by-product, cooling rapidly the filtrate to precipitate a solid, admixing the solid with an acid and heating the resultant mixture, separating the mixture into a solid product and a liquid, washing the solid product with water followed by drying to produce a high purity silica gel. The method allows the production of a high purity silica gel from the husk of a grain which is produced in a large quantity and is treated as a waste, with a simple process mainly comprising heating with an aqueous solution and cooling and with ease. |