Calcium aluminate cement bonded refractory castable is an amorphous refractory material made by mixing calcium aluminate cement as a binder with refractory aggregate, powder and admixtures in a certain proportion. The following is a detailed introduction:
I. Main components of calcium aluminate cement bonded refractory castable
1• Calcium aluminate cement: It is mainly composed of calcium aluminate minerals, such as CA (monocalcium aluminate) and CA₂ (calcium dialumate), which are the key components for providing bonding performance and early strength.
2• Refractory aggregate and powder: Aggregates are usually made of corundum, mullite, high-alumina bauxite, etc. Powder is generally a fine powder similar to the aggregate composition, which determines the basic properties of the castable such as refractoriness and strength.
3• Admixture: Water reducer, coagulant, expansion agent, etc. are often added to improve performance. Water reducer can reduce water consumption and improve fluidity; coagulant can accelerate the setting speed; expansion agent can compensate for the shrinkage of the castable during heating.
2. Characteristics of calcium aluminate cement combined with refractory castables
1• Rapid hardening: Calcium aluminate cement can quickly hydrate at room temperature, so that the castable can obtain high strength in a short time, which is convenient for rapid construction and shortens the construction period.
2• High refractoriness: When combined with refractory aggregates, the refractoriness can reach 1600℃-1800℃, which can meet the use requirements of various high-temperature industrial kilns.
3• Good thermal shock resistance: At high temperatures, the structure formed inside the material enables it to withstand a certain degree of rapid temperature changes, and it is not easy to crack, peel off, etc.
4• Good corrosion resistance: It has a certain corrosion resistance to some acidic and alkaline slags, molten metals, etc., and can be used in a variety of harsh high-temperature environments.
3. Application of calcium aluminate cement combined with refractory castables
1• Metallurgical industry: used for steelmaking converters, linings of electric furnaces, working linings of ladles and tundishes, etc., and can withstand the scouring and erosion of high-temperature molten steel.
2•Building materials industry: In the transition zone and preheater of cement rotary kiln, it can resist the erosion and chemical corrosion of high-temperature materials and improve the service life of the kiln.
3•Chemical industry: It is used for the lining of petrochemical cracking furnaces, gasification furnaces and other equipment to resist high temperature, high pressure and corrosive media.
HOME