Relationship between Cement Proportion and Strength of Refractory Castables

Refractory castable is an amorphous refractory material, which will be the development trend of refractory materials in the future. Because it does not require firing, is environmentally friendly, has simple construction, saves manpower, and is widely used, it is favored by customers. The refractory cement in the refractory castable material is the main factor that determines the initial strength of the castable material, but do not think that the greater the proportion of refractory cement, the better the strength!

Introduction to refractory castable strength-hardening properties

Refractory cement, also known as aluminate cement, is mixed with refractory aggregate, powder, and water. Under the action of the cementing agent, as long as it meets its specific requirements, it can achieve chemical or physical bonding to achieve the hardening of refractory materials with high strength. This process is called hardening. There are three types of hardening, which are introduced in detail below.

1. Water glass is a gas-hardening bonding agent. Its hardening strength requires a dry air environment, but its fire resistance and load softening point are low. It is suitable for parts with high strength, good wear resistance and good acid resistance below 1000℃, but it cannot be used for parts that are often affected by water or water vapor.

2. Phosphate is a thermohardening bonding agent, and its hardening strength must be treated at a certain temperature to achieve it. Its characteristic is that it does not harden and consolidate at room temperature. In order to make it solidify and have a certain strength, a coagulant should be added. Hardening and consolidation until 500℃, the strength also increases. However, at around 800°C, low medium-temperature strength is its disadvantage, and then the strength increases with temperature. The castable has excellent high temperature performance, wear resistance, slag resistance and rapid cooling and heat resistance, and can be used at temperatures of 1400-1600°C.

3. The refractory cement content in the refractory castable is too high. When the binder is added to harden later, it is easy to add a certain amount of water for reaction, so that the castable forms a certain strength during the setting and hardening process. Therefore, we can call this refractory castable The water is hard.

Refractory cement is the main factor that determines the strength of refractory castables. If the amount of cement is incorrect or the cement content is low, the strength of the castable will not be ideal. Therefore, the refractory cement content in the castable should be matched with a reasonable machine, rather than added randomly.