Method for synthesizing tobermorite whiskers by sodium silicate

The invention discloses a method for synthesizing tobermorite whiskers by sodium silicate, comprising the following steps of: preparing sodium silicate and caustic alkali into solution with a certain concentration; dissolving a chlorine-containing compound and an aluminum-containing compound according to a certain silicon-chlorine mol ratio and a certain silicon-aluminum mol ratio; mixing the prepared solution and lime milk according to a certain calcium-silicon mol ratio, using a dynamic hydrothermal method to perform constant-temperature and constant-pressure reaction in a reaction kettle; after reaction; and cooling and filtering the product to obtain the tobermorite whiskers. The method has a simple process and low energy consumption, and the purity of the synthesized tobermorite whiskers is high; the tobermorite whiskers prepared by the invention is needle-like, have complete crystallization surfaces, and can be applied in fields such as the building material, the petrifaction, the ceramic, the biological material, and the like. The comprehensive recovery of high-alkalinity sodium silicate waste liquid produced during the industrial production can be achieved. The method is suitable for industrial application.