Effect of silicon carbide addition on high strength wear resistant refractory castable

March 11, 2019

High-strength wear-resistant refractory castable is a kind of wear-resistant refractory concrete formed by cementing corundum, silicon carbide and other materials with high-strength and low-cement binder.

The melting point of corundum is up to 2050℃, and the coefficient of thermal expansion is 8.6×10-6K-1, which belongs to the material with moderate thermal shock resistance. At the same time, corundum products have high strength. Therefore, the corundum in the castable has a strong resistance to wear. Silicon carbide is widely used in abrasives, heating elements, structural ceramics and refractory materials due to its high hardness, electrical conductivity, high temperature resistance and high strength.

Effect of silicon carbide addition on high strength wear resistant refractory castable

The main difficulty of high-strength wear-resistant castables is to overcome the negative effects of silicon carbide. The silicon carbide particles themselves have good wear resistance. The addition of silicon carbide can improve the corrosion resistance and thermal shock resistance of the castable. However, silicon carbide crystals have few ionic bond components and are hard to be wetted by polar substances. Therefore, after the addition of silicon carbide, the water demand of the refractory castable increases but the strength decreases. If no other measures are taken, the strength of the castable will be affected.

Therefore, in order to give full play to the characteristics of corundum and silicon carbide raw materials and improve the wear resistance of refractory castables, it is necessary to rationally select and blend cement, fine powder and chemical admixtures to improve the strength and line change of the castable after temperature treatment, produce a solid and reliable combination, avoid the shedding of corundum and silicon carbide particles, prevent the intrusion of abrasive particles into the castable, destroy the structure of the castable in relative motion, and obtain good wear resistance.