Can Cracks in Refractory Castables be Repaired?

After the refractory castable is poured, vertical or irregular cracks may appear. This is often caused by the lack of expansion joints or excessive water usage during construction.

After the castable is constructed, it must be baked before it can be put into use. Suppose a large amount of water is added during pouring. In that case, the temperature rises too quickly during baking, or the temperature does not rise straight up without turning back, and the temperature is not well controlled, the expansion force generated by the evaporation of a large amount of water will cause cracks in the product.

So, is there a way to solve the cracks?

That depends on the specific situation and can be solved in different ways.

First, look at the size of the crack. If the crack is no larger than 5mm and there is no mesh-like through-crack, then there is no problem and no need to repair it. This situation basically does not affect the use.

If the crack width of the lining is not large, you can fill some refractory fibers in the crack. This prevents heat from being conducted into the crack and prevents the crack from expanding.

If the crack in the furnace lining is relatively large or some parts have fallen off, the crack and the fallen refractory castable must be removed. Specifically,

1. If the area is less than 10cm×10cm, dig a 5cm hole, clean and wet the hole wall, fill it with castable of the same material, and put it into use after baking.

2. If the crack area of ​​the castable is larger than 10cm×10cm, dig the lining layer to the junction with the furnace wall, small at the top and large at the bottom, and the shape is dovetail. A small amount of anchors must be welded and then filled with castable of the same material.

3. If it is a through crack, it cannot be repaired and can only be re-cast.

If cracks appear in refractory castables, it depends on the situation and different methods are used to solve them. But no matter what the situation is, paying attention to quality is the key. Rongsheng Kiln Refractory Factory is a refractory material manufacturer with rich production and sales experience. Our environmentally friendly fully automatic unshaped refractory castable production line can provide high-quality refractory castable products for high-temperature industrial furnace linings. And provide detailed construction and use instructions. Contact Rongsheng for detailed information.