Low cement castable is a kind of high performance refractory material, which is widely used in high temperature industry. It is made of high-quality aluminate cement as binder, selected refractory aggregate and powder through optimized formula design and strict production technology. Low cement castable has the characteristics of low cement consumption, high density, high strength, good corrosion resistance and thermal stability, and can meet the use requirements under various complex working conditions.

I. Product characteristics

The cement content of low cement castable is significantly lower than that of traditional refractory castable, usually between 2.5% and 5.0%. This characteristic makes it have better volume stability in high temperature environment and reduces the expansion and contraction caused by cement hydration reaction. Its high density and low porosity, usually between 15% and 20%, make it effectively resist the erosion and penetration of slag and furnace gas. Its compressive strength at room temperature can reach 50 ~ 80 MPa, and its compressive strength at high temperature can reach 80 ~ 120 MPa, which can bear a large mechanical load. It also has good thermal shock resistance, which can keep the structure intact in the environment of rapid temperature change, and the thermal shock stability can reach 20 ~ 30 times (water cooling at 1100℃).

II. application fields

Low cement castable is suitable for various high temperature equipment and working conditions. In iron and steel industry, it can be used for lining of ladle, tundish and hot metal ladle, which can withstand the erosion and erosion of high temperature molten steel and prolong the service life of equipment. In the cement industry, it can be used in rotary kiln, calciner, preheater and other parts, and can resist the high temperature and chemical erosion during the sintering process of cement clinker. In the glass industry, it can be used in the breast wall, crown and other parts of glass melting furnace, and can withstand the high temperature corrosion and chemical action of glass liquid. In addition, it is also widely used in petrochemical, electric power, non-ferrous metals and other industries, and is used for lining various high-temperature furnaces, reactors, pipelines and so on.

III. Construction and Maintenance

The construction of low cement castable usually adopts pouring and vibration molding. Before construction, the working face should be cleaned to ensure that it is clean, smooth and free of oil pollution and sundries. Mix the castable with water or other liquids evenly according to the design requirements, and the mixing time is generally 3 ~ 5 minutes. The mixed castable should be used up within 30 minutes to avoid water loss caused by long-term exposure to air. After pouring is completed, proper maintenance is required. At room temperature, the castable needs to stand for more than 24 hours, and then demould after its initial hardening. After that, it needs to be baked. The baking temperature should be determined according to the variety and use requirements of the castable, generally between 150℃ and 600℃, and the baking time should be adjusted according to the size and structure of the equipment to ensure that the water in the castable is fully discharged and achieve the best use performance.

IV. Development trend

With the continuous development of high-temperature industrial technology, low-cement castable is also constantly innovating and improving. On the one hand, researchers are committed to further reducing the amount of cement and developing ultra-low cement castables and cement-free castables to improve their high-temperature performance and service life. On the other hand, the thermal shock resistance, corrosion resistance and mechanical strength of castable are improved by adding nano-materials and fiber reinforced materials. In addition, environmental protection has also become an important direction for the development of low cement castable. By optimizing raw material formula and production process, energy consumption and pollutant emission can be reduced, and sustainable development can be achieved.

Low-cement castable plays an irreplaceable role in high-temperature industry with its excellent performance and wide application fields. With the continuous progress and innovation of technology, low cement castable will provide more reliable guarantee for the development of high temperature industry and help the efficient, stable and sustainable development of industrial production.