Refractory castable is essentially the refractory concrete. Compared with burnt refractory brick, the refractory castables have the following features in performance: 

1. The load softening temperature is much lower than that of the similar refractory brick. 

2. The linear expansion coefficient is smaller, because the sintering shrinkage effect from the binder during the process of heating can offset the expansion of part of the aggregates whey are heated. 

3. If the temperature rapidly varies, which shows the resistivity is good. The hot and cold switching frequencies can be more than 15 times, so it is better than the similar refractory brick. 

4. The shrinkage proportion of reburning line  usually is larger than that of the refractory brick.

5. The overall performance is better than that of the refractory masonry.