| 摘要 |
Silica gel is produced by a composition which comprises an alkali-metal silicate having an alkali-metal oxide to silicon oxide ratio of from 1:3.0 to 1:4.0, water, an amide and at least one additive selected from formaldehyde, paraformaldehyde, and carbohydrate - formaldehyde resins. The additive preferably comprises 1 to 30% by volume of the total composition. A preferred resin is sucrose-formaldehyde resin. The composition may also include a reactive salt capable of forming a substantially water-insoluble gel with the silicate and preferred salts are sodium aluminate, aluminium chloride, copper sulphate, zinc chloride or calcium chloride. The preferred amide is formamide, and the composition preferably contains up to 50% by volume of the reactive salt. The composition is used for stabilizing soils.
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