1. In order to thoroughly hydration the cement, excessive water (10% - 15%) is added to form ceramic high alumina refractory castable with high porosity and low fine density.
2. Calcium aluminate hydrate has strong dehydration and recrystallization effect in the middle temperature stage, which destroys the arrangement structure of hard points in the castable, and makes the strength of high alumina refractory castable decrease sharply in the middle temperature stage.
3. Cement binder will bring more into the castable, which leads to the decrease of the load softening temperature of the ceramic high alumina refractory castable, and the deterioration of the thermal shock and stability function index. In view of the problem that the high temperature function of ordinary high alumina refractory castable is not good, the low cement high alumina refractory castable can avoid the regret of high temperature section function. The so-called low cement and high alumina refractory castable, in which the cement content is less than 8%, while the lower than 4% is called ultra-low cement high alumina refractory castable.
In contrast, the above mentioned deficiencies of ordinary high alumina refractory castables are all transformed into the advantages of low cement and high alumina refractory castable. The structure is very detailed. The results show that the porosity is low, the fire resistance is high, the load softening temperature is high, the high temperature strength is high, and the thermal shock stability is good. But because of its low cement content, forming a long time of coagulation, the early strength is low in winter and low temperature conditions construction is particularly unfavorable. Therefore, pay attention to the building.
