| 摘要 |
FIELD: binding agents. SUBSTANCE: invention relates to binding agents finding use when manufacturing precision-molding shell molds, in papermaking, as dyes, and as water-limiting material for waterproofing. Silicon dioxide hydrogel is prepared by ion-exchange conversion of sodium silicate into polysilicic acid, which is stabilized by sodium-containing solution and resultant silicon dioxide hydrogel is thermally treated with live steam at temperature up to 100 C and atmosphere pressure for 2.5-3 hr. Before heat treatment, silicon dioxide hydrogel can be concentrated to silicon dioxide content 8-10 wt %. EFFECT: optimized process parameters. 2 cl, 2 tbl, 3 ex
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