| 摘要 |
In producing nodular silica sol, a polymerized silicic acid solution with viscosity of silicic acid from 0.9 to 100 mPa·s is prepared by aging a silicic acid solution with pH from 1.0 to 7.0 and silica concentration from 0.05 to 3.0% by weight at a temperature from 1 to 98° C. Then, a seed liquid is prepared by adding an alkali to the polymerized solution to adjust the pH from 10 to 12.5 and heating the resultant mixture solution at a temperature from 50 to 150° C. According to necessity, an alkali is added to the obtained seed liquid to adjust the pH in from 9 to 12.5. Finally, a silicic acid solution or a highly purified silicic acid solution is dropped to the seed liquid at a temperature from 20 to 98° C. continuously or intermittently for building up.
|
