How to solve the problem that the castable mixing has no fluidity and the materials are loose
Castables are mostly dry materials, which need to be mixed with water during construction. The amount of water can directly affect the service performance of castables, which is also one of the most important links in castable construction. When the amount of water added is OK, the castable mixture will also have no fluidity and loose materials. This problem is mostly caused by the following points.
1、 Mesh number of refractory powder
Refractory powder is the matrix material of amorphous refractory materials. The fineness (mesh) shall be between 140 mesh and 200 mesh, and shall not be greater than 200 mesh. If the powder is too fine, the overall water absorption of castable will be large, the mixing logistics will be loose and cannot be condensed. Affect the final properties of castable.
2、 Particle grading of refractory aggregate
In the castable, the refractory aggregate plays the role of skeleton, and the amount is between 65-73%. In fact, the overall amount of aggregate is still very good, but the particle gradation is particularly important. Generally, the aggregate particle size is generally 0-3mm, 3-5mm, 5-8mm and 10-15mm. Generally speaking, the aggregate gradation must be large and small (large aggregate accounts for 60-65% of the total aggregate and fine aggregate accounts for 35-40% of the aggregate). The ideal particle gradation is that the gap caused by coarse aggregate is just filled by fine aggregate, and the gap between them is just filled by powder. If the size aggregate particle gradation is unreasonable, the castable will have no fluidity.