The substratum of low cement in castable refractories is to replace part of calcium aluminate cement with ultrafine powder of the same chemical composition as the main material of the castable, At the same time adding a small amount of dispersant and a certain amount of delayed coagulant preparation. The refractory castable has the following advantages by replacing calcium aluminate with ultrafine powder:
1.The low content of CaO in castable refractories can reduce the low eutectic phase generated in the material, thus improving the refractoriness, high temperature strength and slag resistance.
2.The water demand of castable refractories is only 1/2~1/3 of that of ordinary refractory castable, so the porosity is low and the volume density is high
3. Less cement hydrate is generated after molding and curing, During heating and baking, there is no problem that the strength of medium temperature decreases due to the failure of hydration bonds, With the increase of heat treatment temperature and sintering gradually, the strength also increases gradually.