Application of refractory clay in refractory bricks

When masonry, refractory mud is also used, just as cement is needed to build a house. The main function of refractory mud is to play the role of bonding and joint refractory bricks, with high bonding strength, strong erosion resistance, good plasticity and convenient construction. Refractory mud can be divided into clay, high alumina, siliceous and magnesia refractory according to the material, and acid refractory materials, neutral refractories and alkaline refractories according to chemical characteristics. Masonry refractory bricks should be matched with refractory mud of the same material, but the load softening starting point of refractory mud is lower than that of refractory bricks, because the refractory mud produces large volume shrinkage at high temperatures. Therefore, quality requirements are more important.

When masonry bricks, clay refractory mud should be used, which is composed of clayey clinker and bonded clay.

When masonrying high aluminum bricks, high aluminum refractory mud is applied, when masonry AL2O360-75% high aluminum bricks, high aluminum refractory mud with aluminum content of more than 50% should be used, and clay refractory mud with high refractory degree can be used when masonry AL2O348-55% high aluminum bricks.

When masonry silicon bricks, siliceous refractory mud with a SiO2 content of 90-93% is applied.

When masonrying magnesia bricks, magnesium refractory mud is used, and its magnesium oxide content is not less than 78%,

So how should refractory mud be prepared and used?

1. When masonrying different refractory bricks, the refractory mud of the corresponding material should be used, and it should not be mixed.

2. The stirred refractory mud should be used immediately, and the hardened refractory mud can no longer be used.

3. Refractory mud should have proper viscosity and fluidity, so that the gap between bricks and bricks is as small as possible (even less than 1 mm). The refractory mud on the refractory brick should fill the entire surface to facilitate the formation of a complete expansion joint.

4. The particle size of refractory mud generally adopts fine-grained refractory mud, which can also be selected according to the thickness of the gray seam, and the maximum particle size should not be greater than 30% of the thickness of the gray seam.

The importance of refractory mud?

The preparation and construction of refractory mud directly affects the life of refractory masonry, if the adhesion is not strong, or the powder is too coarse, it will also affect the use of refractory bricks. During construction, bonding the mud of refractory bricks, the amount of water added must be well controlled, the amount of water added is too large, and the mud is easy to flow from the brick joint; The amount of water added is too small, the mud is dry, and the bricks cannot be bonded.

Refractory mud is subjected to the same load and high temperature as refractory bricks, especially in refractory brick masonry in large kilns. The load softening temperature of refractory mud is one of the indicators of the high-temperature performance of refractory mud, which can reflect the actual use characteristics of refractory mud, and can also directly judge the temperature range of high-temperature volume shrinkage of refractory mud under load. At the same time, refractory mud is an important bonding joint material in the process of refractory brick masonry, and its role is even more important than refractory bricks, if the quality of refractory mud is not good, it will seriously affect the service life of refractory bricks. In other words, the importance of refractory mud is higher than the importance of refractory bricks.