METHOD FOR PRODUCTION OF SODIUM SILICATE Russian patent published in 1995 - IPC

FIELD: production of sodium silicate. SUBSTANCE: water glass is prepared by reaction of quartz sand with solution of sodium hydroxide at molar ratio of SiO₂:Na₂O= (2.0-2.8): 1 at 180- 240 C and pressure of 10-30 bars. Produced water glass is treated in zone of spray drying with hot air having temperature of 200-300 C for 10-20 s to form powdery amorphous sodium silicate with moisture content of 15-23 mas. (determined as calcination losses at 700 C) and bulk mass above 300 g/cu.dm. Powdery sodium silicate is charged into tube rotating furnace provided with inclined device for moving solid matter, and treated for 1-60 min at 250-500 C with counterflowing flue gas. Tube furnace is insulated so that temperature of its external wall is less than 60 C. Amorphous sodium silicate coming out of tube rotating furnace is ground by means of mechanical crusher down to particles sizing 0.1-12 mm. EFFECT: higher efficiency. 4 cl