corundum mullite castable made electric furnace cover

How to improve the quality of refractory castables used in electric furnace cover?

The use of refractory castables for integral casting of prefabricated blocks in the triangular area of the electric furnace cover has been widely promoted and used. In the selection of materials, the electric furnace cover is mainly made of corundum, chrome corundum, high alumina, mullite, etc. Material of refractory castable prefabricated blocks. The refractory prefabricated block has good integrity and corrosion resistance, simple masonry construction and relatively guaranteed construction quality, which greatly improves the overall quality of the electric furnace cover.

Generally, the triangular area of the ultra-high-power electric furnace cover is made of corundum (chrome corundum) prefabricated parts. High-alumina and mullite prefabricated blocks are widely used in the triangular area of high-power electric furnace covers.

How to improve the quality of refractory castables used in electric furnace cover?

In order to improve the quality of refractory castables, the following technological measures can be taken.

①The aggregate plays the role of skeleton and support, and the matrix plays the role of filling the pores, wrapping the aggregate and connecting the aggregate. Therefore, the raw material with high purity, few impurities and stable volume at high temperature is the primary condition.

② In order to obtain good high temperature performance, try to control the content of CaO, that is, reduce the amount of cement as much as possible. With the increase of CaO content, the liquid phase content increases greatly with the increase of temperature.

③Add an appropriate amount of tAIzOs to improve the strength at medium temperature. The volume shrinkage caused by the crystal transformation in the intermediate temperature stage improves the intermediate temperature strength.

④Add an appropriate amount of soft clay as sintering agent to promote liquid phase formation and sintering in order to form a ceramic bond.

⑤ Improve the volume shrinkage of the material during the sintering process, and add additives (kyanite, sillimanite, etc.) that produce expansion effects at high temperatures.

⑥ Add heat-resistant non-short steel fiber to improve thermal stability and toughness.

⑦Add an appropriate amount of antiknock agent to facilitate the smooth discharge of water vapor and improve the baking quality.

From the perspective of long-term production practice, although the development of new steelmaking technology may lead to partial selection of basic materials for electric furnace covers, high-alumina furnace cover materials made of carefully selected high-quality raw materials, including new ones containing "three stones" Varieties, corundum, mullite, etc., as well as new materials such as castables combined with ultra-fine powder and chrome corundum, can meet the needs of new technology development.