Aluminate cement, also known as refractory cement, 625 cement, high alumina cement, CA-50 cement, etc., is a special cement. Aluminate cement has a wide range of applications and is an essential refractory adhesive in many refractory concretes. Aluminate cement is a special cement mainly composed of weakly alkaline calcium aluminate salt. It is made from bauxite and limestone, which is calcined to obtain clinker mainly composed of calcium aluminate with an alumina content of about 50%, and then ground into a water-hardening binder. Aluminate cement can be used at a temperature of up to 1350℃. By proportionally mixing it with high-alumina aggregates and other refractory materials to make refractory castables, the refractory temperature can reach 1700℃.
Aluminate cement can be classified based on the alumina content into CA-50 and CA-75 (also known as calcium aluminate cement, which is white) and is a water-hardening binder with fast setting, early strength, corrosion resistance, and high-temperature resistance. Aluminate cement can be yellow-brown or gray. It has a wide range of applications in the metallurgy, machinery, building materials, petrochemical, power, food industries, etc.
Some applications of Aluminate Cement are:
Used to make refractory castables for kiln lining.
Suitable for projects that require resistance to sulfate corrosion.
Suitable for concrete engineering applications that require fast setting and emergency repair.
Suitable for winter construction and special projects that require early strength.
Used as raw material in producing water purifiers (calcium aluminate powder).
Used as the best raw material for producing decorative materials (such as artificial marble, colored pavement bricks, colored wave tiles, etc.).
An important component of expansive cement, self-stress cement, and other special cements.
After the formation of the aluminate cement refractory casting, it is essential to place it under the proper curing regime. Depending on the curing regime, the ambient and drying compressive strength may differ. This is due to different hydration products and crystal types transitions. In general, since the heat of hydration of cement after water addition is concentrated in 2-8 hours and can reach around 80%, the strength of early age increases quickly, resulting in only slight increases in strength after 1 day at room temperature and the first three days of curing. Drying strength is better when cured in a humid or steam environment.
In production, under various factors of influence, to prevent the surface of the castable from being loosened due to early water loss and carbonation, casts should be cured in a humid environment after initial setting, with the temperature ranging from 15℃~25℃, and the curing time being 2 to 3 days in total.