The silica sol is an aqueous dispersion of SiO 2 particles of a few nanometers to several tens of nanometers, has a low viscosity, and has good dispersibility and permeability in the castable. When the silica sol gels under the action of the curing agent, the silanol groups on the surface of the nano-SiO 2 particles are polymerized; in the subsequent drying and dehydration process, the SiO 2 particles are further polymerized, and the matrix fine powder and the fine powder particles are firmly fixed. integrate. Therefore, the silica sol combined with the corundum-mullite castable sample has a higher drying strength.

      Most of the castables used in steel mills are cement and low cement combined with high alumina castables. These castables generally need to be cured for 2~3d after molding and curing. After the mold is removed, the oven is generally required to be 7d. In order to pursue the high efficiency and longevity of the blast furnace, it is necessary to repair the hot body of the furnace, which cannot be satisfied by the cement, resin and tar bonding materials, because the cement bonding material needs sufficient moisture and curing time to have good performance. The resin and tar bonding materials generate harmful gases during hot construction. For this reason, the jade-mullite castable for blast furnace hot repair was developed with silica sol as binder.

        (1) Silica sol combined with corundum-mullite castables have high post-drying strength and high-temperature post-treatment strength, and have good thermal shock resistance.

(2) In practical applications, the demolding time and oven time of the castable are greatly shortened, can be cast hot, and have good performance.