Preparation And Characterization Of Guangxi Tiandong Bentonite Inorganic Gel

Bentonite inorganic gel is a high added value product with large capacity, high viscosity, easy to produce and unique colloidal properties, which was prepared by deep processing of bentonite. Gel treatment can not only improve the characteristics of the suspension stability and thixotropy, but also gain a lot of new excellent performance. The inorganic gel is one of the most promising of cementitious materials in today's market.Sodium bentonite was obtained by sodium purification experiment based on the bentonite's mineral properties and physicochemical properties. The bentonite inorganic gel samples with high viscosity were prepared in optimized conditions. The formation mechanism of bentonite inorganic gel was analyzed. On the basis of these experiments, the application of bentonite inorganic gel in aqueous emulsion paint was preliminarily explored. The experiment compared some properties of aqueous emulsion paint before and after adding inorganic gel.The results showed that the physicochemical properties of bentonite in Guangxi Tiandong were as follows:its expansion index was 5 mL/2g, colloid index was 32 mL/15g, cation exchange capacity was 52.08 mmol/100g, the content of montmorillonite was 72.6%. Sodium bentonite was obtained by sodium modification with its expansion index 68 mL/2g, colloid index 325 mL/15g, cation exchange capacity 89.65 mmol/100g, and the content of montmorillonite up to 92%. Compared with the raw bentonite, and their physicochemical properties were improved significantly. The optimal conditions for the preparation of bentonite inorganic gel were as follows:the gelling agent was 2.5% CaO, the pulp mass fraction was 5%, pH value was 9, and gel reaction was 20 min at room temperature. The viscosity of the prepared inorganic gel was up to 6250 mpa·s. The application of bentonite inorganic gel in aqueous emulsion paint was researched and the result showed that the performance of waterborne emulsion paint has been improved and easy to store when added a small amount of inorganic gel sample.