Advantages and applications of low cement castables
Low cement castables have lower cement content than ordinary refractory castables. The castable is made of refractory aggregate and powder as raw materials and then mixed with binder and additives. The binder used is basically aluminate cement. The amount of cement added in the castable will affect the overall performance and high temperature. Therefore, low-cement and ultra-low-cement castables have better performance.
1. The cement addition amount of the low-cement ultra-low cement castable is 1/2-1/5 of the ordinary refractory castable, and the calcium oxide added to the castable is reduced to less than 2.5%, which improves the refractoriness, slag resistance and high temperature strength, etc. The low melt reduction at high temperature also improves the high temperature flexural strength and wear resistance of the castable.
2. The amount of water added when mixing low-cement castables is only half or less than that of ordinary castables, the porosity is reduced, and the bulk density is increased, which can be comparable to refractory products of the same material.
3. The low-cement castable has basically no cement hydrate after molding and curing. It will not affect the strength during heating and baking, and will gradually sinter with the increase of temperature, and the strength will gradually increase. The difference between low-cement castables and ordinary castables is that they have higher strength at 900-1200 °C. Whether it is high temperature or normal temperature, the strength of low cement castables is better than that of ordinary castables.
Low cement castables are widely used:
It is suitable for lining of various heat treatment furnaces, heating furnaces, shaft kilns, rotary kilns, electric furnace covers, blast furnace tapholes, etc.; self-flowing low-cement castables are suitable for integral lance linings for injection metallurgy, petrochemical catalytic cracking reactors High temperature wear-resistant lining body, outer lining of heating furnace water-cooling pipe, etc.
There are many advantages of low-cement castables, so it is necessary to strictly follow the manufacturer's construction standards during construction to ensure the performance of low-cement castables.