| 摘要 |
PURPOSE:To produce a homogenous sol at the ordinary temp. even when a high-concn. mineral acid and a sodium silicate soln. are used by bringing a mineral acid into contact with the sodium silicate soln. in the specified flow velocity and above in the titled method gelatinizing a silica sol obtained by bringing the mineral acid into contact with the sodium silicate soln. CONSTITUTION:A mineral acid is mutually brought into contact with a sodium silicate soln. in >=10m/sec flow velocity to produce silica sol and thereafter it is gelatinized. For example, each raw material liquid is fed to the feed pipes 1, 1' of the raw materials from the storage vessels 5, 5' of the raw materials in <=1m/sec flow velocity with the pumps 6, 6' by using a Y-type reaction. The flow velocity of each raw material liquid is made to >=10m/sec by means of the throttle parts 4, 4' provided to one part of the pipes 1, 1'. The distance up to a reaction part 3 from the throttle parts 4, 4' is preferably regulated to 1-3 times of pipe diameter of the pipes 1, 1' in order to allow the reaction to perform homogenously. The sol obtained by such a method is stored in a gelatinizing vessel 7 through a discharge pipe 2 and made to gel. The silica gel product is obtained by washing and drying this gel.
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