Refractory castables are made of refractory cement (10%~15%, weight ratio) and refractory aggregates, so casting refractory cement is also an indispensable part.
The Role of Casting Refractory Cement
The role of casting refractory cement in refractory castables is the binder. It affects the setting time of the refractory castable. At the same time, due to the nature of the castable refractory cement itself, it also causes a series of performance degradation of the refractory castable.
Main Properties of Castable Refractory Cement and Its Effect on Refractory Castables
- In order to completely hydrate the cement, excessive addition of water (10%~15%) is required to cause the ceramic refractory castable to have a high porosity and a decrease in density.
- Calcium aluminate hydrate has strong dehydration and recrystallization effects in the middle temperature stage, which destroys the microstructure of the hard spots in the castable, and the strength of the refractory castables drops sharply in the middle temperature stage.
- The cementitious binder brings more calcium into the castable, which leads to a decrease in the load-softening temperature of the ceramified refractory castable, and the thermal shock stability index deteriorates.
Low Cement Castables Properties
In view of the problem of poor high temperature performance of ordinary refractory castables, low cement refractory castables effectively avoid the regret of high temperature performance. The low-cement refractory castable, often mentioned, has a cement content of less than 8%, while less than 4% is called an ultra-low cement refractory castable.
In contrast, the deficiencies described above for conventional refractory castables translate into the advantages of low cement refractory castables. Its structure is dense. The apparent porosity is low, the refractoriness is high, the load softening temperature is high, the high temperature strength is high, and the thermal shock stability is good. However, due to its low cement content, the condensation time is long, and the early strength is low, which is particularly unfavorable in winter and low temperature conditions. Therefore, pay full attention when construction lining.
Casting Refractory Cement Manufacturer
As a manufacturer of refractory materials, Rongsheng is committed to the production and development of refractory bricks and refractory castables. It is designed to provide customers with refractory castable products that meet the needs of customers’ thermal equipment. Our casting refractory cement with low cement Can also help you more. Email to Us for free quote.