April 25, 2022
How is cementless castable bonded
Cementless refractory castable is a high-grade castable, which is produced by composite ultra-fine powder technology or sol.
Because there is no cement, the calcium content of the castable is less than 0.2%, and the low melt formed is very few, so the performance of the castable is better than that of the general low cement castable.
The varieties of cementless castables include aluminum silicate, mullite, corundum, magnesium series and silicon carbide series. The setting and hardening of this kind of castable is through the coagulation and combination of ultra-fine powder, and the strength is obtained by the coagulation and combination. The admixture plays the same role as the low cement castable.
Cementless castables use oxide ultrafine powder as binder, or silica sol and aluminum sol as binder. They can also be used in combination. For example, alumina ultrafine powder or silica ultrafine powder is used for corundum castable. Aluminum silicate castable uses silica ultrafine powder plus alumina ultrafine powder, or silica sol as binder. For example, the wear-resistant spray coating for blast furnace lining is the material combined with silica sol, and the application effect is good.
The cementless castable is coagulated by adding and dispersing or dissolving the ultrafine powder or colloid in the castable, so that the castable has a certain fluidity. After stirring and vibration forming, the castable coagulating is added by adding the gel.
Although the hardening process of cementless castable is slow, the strength increases with the increase of temperature. Aluminum silicate cementless castable will expand slightly after burning, and corundum will shrink, but it has excellent high temperature performance.
The non cement refractory castable has low impurity content, and its fire resistance, corrosion resistance and high-temperature structural strength are better than those of Low Cement Castables. The raw material of this castable is used with high aluminum material and carbon containing material, and its application effect will be better.