METHOD OF PREPARING SODIUM POLYSILICATES Russian patent published in 1999 - IPC

FIELD: oil and gas production; insulation materials. SUBSTANCE: sodium polysilicates are prepared by sodium silicate-silicon dioxide interaction at 70-100 C, which is accomplished by adding 10-16 wt % silicon dioxide hydrogel to 20-30 wt % aqueous sodium silicate solution, ratio of the two components being (1-1.5):1, respectively. Product is finally aged for up to 0.5 hr. Sodium polysilicates can also be prepared when anhydrous sodium silicate is added to 7-12.5 wt % silicon dioxide hydrogel at ratio 1:(4.43-7.06), respectively, for 2.5-4.0 hr. EFFECT: fourfold increased sodium polysilicate solution stability due to prevented gel formation. 3 cl, 1 tbl, 6 ex