Mechanism of Increase in Strength of Sodium Silicate-bonded Sandby Silica Sand Surface Modified in High Temperature

With the aid of XRD,SEM. EDS etc., there is absorbed film on sand grain surface, high temperature modify makes the film sintered firmly on sand grain surface. Thus it changes physical and chemical characteristics of the film and sand grain surface, improves the wetting properties greatly, makes the fracture features of bonding bridge change from the adhesive to the cohesive and raises the strength of sodium sili-cate-bonded sand.