| abstract |
PURPOSE: To obtain a slurry or powder for an industrially useful filler by ageing and polymerizing a geothermal fluid, thereby forming a Si sol, thereafter cooling the Si sol and thereby forming a tertiary aggregate structure. n CONSTITUTION: The geothermal fluid with an SiO 2 concentration of 400 to 1400 mgKg -1 as Si is fed into a flush cooler/condenser 3 from a weir box of a silenser via a pump 1, is flushed, and the obtd. fluid is introduced into an ageing tank via a pipe 2 at bout 100°C. Next, the fluid is aged at a pH of 5 to 9.5 for about 2 hours, is thereafter cooled to about 30°C and is supplied to an adjusting container at a flow rate of about 10 Kgs -1 . Thereafter, the fluid is supplied to a dissolved air floating(DAF) tank arranged with a suspended matter-scooper, air saturation vessel, etc., via a pipe 7. Next, about 50% of a discharge liq. obtd. by introducing the precipitated slurry produced by adding a coagulating agent such as CaCl 2 from a holding tank into a separation plant is re-circulated with a pump 13 and is refluxed to the DAF tank. Next, the coagulated suspended matter is fed to a silica storage tank, is dried and is pulverized to produce precipitated amorphous silicas. n COPYRIGHT: (C)1991,JPO |