What is the difference between low cement castables and traditional castables?
There is a big difference between low cement castables and traditional castables, mainly in the difference between mid-term strength and late-stage strength. Traditional castables have poor mid-term strength, while low-cement castables are far better than traditional refractory castables. Not only the cement dosage Low, low calcium content, and also uses ultra-fine powder technology to distribute the castable particles in a reasonable proportion, and the late-stage strength and mid-term strength of the castable are further improved.
1. Overview of high-strength castables
Compared with traditional refractory castables, low-cement castables have high density, low porosity, and higher room temperature curing strength; they also have good volume stability and have smaller volume shrinkage after drying and calcining. The high-strength low-cement material in low-cement castables is formulated with pure calcium aluminate cement as the binding agent. The service temperature of high-strength castables reaches 1600°C and has good wear resistance at high temperatures. High-strength, low-cement castables are suitable for use in various kiln linings with high temperatures and strong corrosiveness.
2. Description of low cement castables
The low-cement material using fused white corundum as aggregate is called low-cement corundum castable. The corundum-based low-cement material has high mechanical strength, erosion resistance and abrasion resistance, and the service temperature reaches 1700℃. , Low cement corundum castable is suitable for use in large cement kiln mouths, multi-cylinder cooler elbows and other lining parts where the temperature is above 1400°C and where impact erosion is severe. And it is suitable for use in all parts of the kiln lining exceeding 1400°C.
3. Traditional performance is not as good as low cement castables
Traditional refractory castables are made of refractory particles and powders, as well as high alumina cement. The particle gradation of the aggregate part is not as fine as that of low cement materials. The cement particles are also coarser, and the proportion of cement added is large, and the amount of water added during construction is also large. In addition, the amount of cement is large and the particles are not classified, so the cement material cannot be fully hydrated, especially at a temperature of 800°C, it basically has no strength, so the performance of traditional castables is not as good as low-cement castables.
