Anchor brick is an essential refractory brick that plays a crucial role in high temperature kilns. Its primary function is to anchor refractory castable or refractory plastic, and it is typically used when the temperature is above 1000℃. Anchor brick acts as a skeleton in refractory castable and is also known as a hanging brick. This article will delve deeper into the significance of anchor bricks and their applications in high temperature kilns.
The Role of Anchor Brick in Refractory Castable
Anchor brick is one of several products that serve as the framework in refractory castable. The other two products are anchors and tortoise shell nets, which are metal products. In contrast, only anchor bricks belong to the category of refractory products. The primary function of anchor bricks is to anchor and strengthen the refractory castable lining.
Anchor bricks come in various shapes and connection modes, and their sizes are different. Usually, they are customized according to the user’s needs. Some anchor bricks have a regular length of 330, 380, 440, and 500mm, with a thickness of approximately 100mm. The shape and size of the anchor brick play a critical role in its function as an anchor and support for the refractory castable.
Properties of Anchor Brick
Anchor brick is a refractory brick formed by raw material technical proportioning, re-molding, and sintering. It has high strength, good thermal shock stability, and toughness. However, the mold of the anchor brick is a challenge in the production process, and the abrasives are complex and difficult to make, which makes the production cost higher than that of ordinary refractory brick.
The alumina content of the anchor brick is more than 55%, and in excellent anchor brick, it can reach 75%. The load softening temperature of this type of brick reaches 1550℃, making it an excellent refractory brick product. However, generally, the anchor brick with an alumina content of 55% is preferred because it has better flexibility.
Applications of Anchor Brick
When using castables, anchor bricks are often used to ensure the stability of the castables, improve the overall tightness of the construction structure, increase the service safety factor of the kiln, and prolong the service life of the kiln. Anchor brick’s properties should be consistent with the castable material and its expansion and contraction to form a close combination with the castable.
If an anchor brick is provided with a hole, the installation hole is usually in the neck. The finished anchor brick should be free of cracks, and the size should be accurate to make it easy to use on the furnace top. Generally, three-level high alumina anchor bricks are preferred because of their toughness. Although the quality of grade I high alumina brick is good, its hardness increases, making it easy to crack when used in general castables.
Conclusion
Anchor brick plays an essential role in high temperature kilns by anchoring and supporting refractory castables. The properties of anchor bricks should be consistent with the castable material and its expansion and contraction to form a close combination with the castable. By using anchor bricks, the stability of castables can be ensured, improving the overall tightness of the construction structure, increasing the service safety factor of the kiln, and prolonging the service life of the kiln.
