Refractory castables are mainly used in metallurgical industry furnaces, and are also widely used in oil, chemical, building materials, electric and mechanical industrial furnaces and thermal equipment.
CASTABLE REFRACTORY PROPERTIES: https://microsilica-fume.com/castable-refractory-properties.html
With the development of amorphous refractory technology, silica fume has been widely applied in castables, because of its advantages such as micron size, amorphous structure, high activity and spherical structure. The application of microsilica fume powder has become the key technology in the low cement and ultra-low cement castable system.
High quality microsilica has super fine particle size, low water storage and high fluidity. It is widely used in high-performance refractory castables, sinter auxiliaries for silicon nitride, ladle materials, self flow refractory castables, prefab, low (no) Cement Castables and dry wet spraying materials.
Micro silica fume features:
The average diameter of a microsilica sphere is about 0.15 micron. Although some of the spheres exist as single entities, most of them form primary agglomerates. The size of these may vary between 0.1 and 1 micron. This rather wide particle size distribution contributes to high packing efficiency.
Microsilica has no internal porosity, and the specific gravity of microsilica is about 2.3 g/cm3. The specific surface area may vary between 15 and 30 m2/g.
Microsilica’s benefits:
Dense castables;
Improved flow;
Hot strength;
Strength during heat-up;
Glass and ceramics: Kiln furniture;
Grades recommended for refractories;
Effect of silica fume:
Can be as binding agent of refractory material and kiln materials, surfactant and mineralizer, is conducive to the improvement of refractory solid phase reaction and sintering driving force, reinforcement reaction speed and sintered density, conducive to the transformation of crystal stable structure, improve the high temperature properties of materials.
Advantages of microsilica for castable:
1. There are many pores in the traditional castable, and the micro silica fume is filled in the pores, which improves the volume density and the porosity, and the strength can be enhanced obviously.
2, microsilica has strong activity, can form colloid particles in water, adding proper amount of dispersant, can enhance the fluidity, thus improving the pouring property.
3, micro silica fume is easy to form -Si-OH base in water, which has strong hydrophilicity and activity. It can enhance the agglomeration of refractories, and improve the performance of high temperature at the same time, and prolong the service life of refractory products.
4, micro silica powder added to the refractory castable has about 5 times effect of cement. It can reduce the cost in the application of ordinary concrete and low cement castable, and improve the durability.
5. Improve the compactness of the castable refractory. With Al2O3 coexist, easy to form mullite phase, high temperature strength, heat shock resistance enhancement.
If you want to know more about silica fume, please contact us by Email sales@superior-abrasives.com, with your needed bulk density, your needed amount and your application. We will reply you in 24 hours. Thank you.
