Measures to solve the burst of refractory castable

 

At present, there are two main measures to improve the bursting resistance of refractory castables, reasonable drying and heating system and application of explosion-proof additives. Due to the different production conditions in different kilns, it is difficult to formulate a unified and reasonable drying and heating system. Therefore, anti-explosion substances are often added to improve the anti-explosion performance of refractory castables. The new high-strength corrosion-resistant castable has excellent corrosion resistance and good thermal shock resistance, which makes it widely used in the lining of key parts of large kilns. In the production process, the structure, particle size distribution, material and additives were adjusted to improve its anti-cracking performance, but at the same time, some problems were brought, such as too fast setting speed, delayed hardening and instant loss of fluidity, which caused the refractory castable to burst from time to time.


In view of the fact that high-strength and corrosion-resistant refractory castables often burst with a burst thickness of 50~100mm, it is proposed to use polypropylene explosion-proof fiber which is commonly used in refractory castables to improve or solve the recurrence of such problems. Polypropylene explosion-proof fiber is made of polyethylene, with thin fiber and large length and diameter, so it has a large specific surface area, which is helpful to soften and melt, which is of course related to the low melting point of the material itself. The spalling and bursting mechanism of refractory castables means that refractory castables are the result of high steam pressure and uneven thermal stress produced during baking.


During the baking process, a large amount of internal steam, especially the evaporation of crystal water in the castable, easily volatilizes to the surface of castable through pores at 150~250℃. If the temperature control is improper at this time, the excessive vapor pressure in the castable will cause the casting body to burst. Therefore, the polyethylene explosion-proof fiber is used to make use of its physical characteristics of low melting point and low melting. In the temperature range (150℃~220℃) during the baking process of refractory castable, the melting of the polyethylene explosion-proof fiber will produce a gap, and the spacing will cause a drawing effect, which will minimize the impact on the expansion of the casting body during the evaporation of the internal steam of crystal water. 

Wanhao is a manufacturer who is specialized in designing various kinds of furnace and making refractory products for electric furnace, ladle, tundish, blast furnace, AOD furnace, IF furnace, etc.

Company name ：Luoyang Wanhao New Material Co., Ltd.

More Refractory Products: http://www.wanhaorefractory.com/en/product.html

Website: http://www.wanhaorefractory.com/

 

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