CA-70 cement refractory castable

CA-70 cement refractory castable

CA-70 cement refractory castable is made of CA-70 cement as a binder, mixed with refractory aggregates and powders or admixtures in proportion, and after adding water, stirring, forming and curing.

The difference betwwen CA-50 and CA-70 cement refractory castable

The main mineral phase of CA-70 cement is CA2. Compared with CA-50 cement, it is characterized by slow hydration speed, high later strength and high refractoriness. Therefore, the use of CA-70 cement to configure refractory castables and curing under normal temperature and overtime conditions also exhibits lower early strength and higher late strength. Such as high temperature or steam curing, the effect of fast hardening and high strength can also be achieved. In addition, because of the high content of CA2, there will be more aluminum glue formed after hydration, so more activated alumina is produced after heating and new minerals are formed, which is beneficial to improve the performance of refractory castables.

CA-70 cement refractory castable initial setting

    After the initial setting of CA-70 cement refractory castable, it can be cured by two methods: standard curing and steam curing. The curing method is different, the compressive strength at room temperature is also different.

    After CA-70 cement refractory castable is formed and initially set, the standard curing time is 28 days, and the compressive strength can reach 40~60MPa. For example, if the 28d intensity is 100%, the percentage of the intensity increases with age: the normal temperature pressure resistance for 1d is 15~17, the 3d is 35~40, the 7d is 50~60, and the 14d 70~80 , 21d is 85~90: When steam curing is used, the time of heating-constant temperature-cooling is 4h-10h-4h, and the constant temperature is (80±5)℃. The compressive strength after steam curing can reach 60%~80% of the 28d standard curing strength. CA-70 cement castable has a high refractoriness, generally about 1790℃: the softening temperature under load is lower than that of high alumina bricks, which is caused by not pre-calcining.