What is low cement refractory castables？

Low-cement castables use calcium aluminate cement as a binder, and castables with a CaO content of less than 2.5% are generally called low-cement refractory castables. It has the characteristics of low porosity, small pore size, high density, good volume stability, high strength, and a small amount of water. It overcomes the significant decrease in strength of ordinary castables at 800-1200°C and increases with temperature. High and raised, this can more than double the thermal shock resistance of the furnace body.

The difference between low cement castable and ordinary castable

Different from ordinary castables, low cement refractory castables are made of ultrafine powder (particle size less than 10 microns) with the same or similar chemical composition as the main material to replace most or all of the high alumina cement, optimize the particle grading, fine powder, particle morphology, and other factors, and add a small amount of dispersant (water reducer) and the appropriate amount of retarder and other composite admixtures.

Low cement refractory castable properties

(1) The low CaO content in the castable can reduce the formation of a low eutectic phase in the material, and improve the refractory temperature, high-temperature strength, and resistance to slag erosion.
(2) The water consumption of the castable during construction is 4%-6% of that of ordinary castables, with low porosity and high bulk density.
(3) After casting, less cement hydrate is generated during curing, and there is no large amount of water splash bond destruction during heating and baking, which leads to a decrease in medium temperature strength. As the heat treatment temperature increases, the strength gradually increases.
(4) The particle size composition of the castable can be appropriately adjusted to make self-flowing castables and pump-injected castables

Low cement refractory castable application

Low cement refractory castables are mainly used in metallurgy, electric power, nonferrous metals, petrochemicals, building materials, and other industries, such as glass kiln bottom, front and rear kiln door covers of cement kilns, front, and rear kiln openings, coal injection pipes, etc.; various heat treatment furnaces such as heating furnaces and soaking furnaces; medium frequency induction furnace linings, high-temperature wear-resistant linings of petrochemical catalytic cracking reactors, and other industrial furnace linings.