The reason for surface cracks of refractory bricks after used a period of time

Although the fire brick is good, the structure is relatively stable, but the  refractory  brick used for a period of time, some customers reflect the surface of the refractory brick cracks, which is what causes it? After many years of research and experience, the main reason is that the surface of the refractory brick is four points. Today’s technical staff for you to read.

1, the raw material itself is dry and sensitive coefficient

The drying coefficient of raw material is the possibility of cracking of the product, the higher the drying coefficient is, the more easily the product is cracked, the lower the coefficient is, and the more difficult the product is. So we must be careful when choosing raw materials, as far as possible to choose dry sensitive coefficient of raw materials.

2, inappropriate production measures

Production without attention to the ratio of raw materials, if the mix is not uniform will cause the product crack, which requires us to pay attention in the production of the source, to avoid cracking in the future.

3, dry reasons

The air temperature is too high, and the furnace preheating is too short and the ventilation quantity is too large, so the reason of the crack is caused by the fire.

4, roasting reasons

A gate is not reasonable, the fire cooling too fast, too fast, will lead to uneven heating, it will cause cracks in refractory brick.

Above brick appear on the surface of the crack by Xinmi Changxing refractory to provide you with, more on the refractory brick consulting; please pay attention to our website.

Clay bonded castable refractories

Clay bonded castable refractory system combined with clay (i.e. soft clay as binder, its working principle is by clay alkali replacement given construction, high temperature is formed ceramic combination, and generates acicular mullite, interspersed with each other, compact structure,
high temperature and good performance.

Clay alkali replacement is in the mud and clay, when adding a thicker water film of metal ion, hydrogen ion replacement clay colloid diffusion layer, the diffusion layer thickness, increase the potential, increase the clay particles are negatively charged and improve the fluidity of the slurry can be poured to construct; when adding metal ions with thin water film, replacement of water film thickness of metal ions, the role and the opposite, the fluidity of the slurry and reduce the flocculation, resulting in clay bonded castable hardening. The former, commonly known as the glue solution or water reducing agent is widely used substances containing sodium ions, such as sodium tripolyphosphate; the latter, known as flocculent and coagulant, general use of lime and Portland cement, aluminates cement and magnesium hydroxide containing substances of calcium and magnesium ions.

It should be pointed out that when the clay bonded with the refractory castable is prepared, the adhesive agent and coagulant are added simultaneously and interact with each other. In order to make clay solution of glue and convenient construction and promoting hardening and the formation of strength, so we should choose delayed coagulant and dosage should be appropriate.

Clay bonded castable refractory material is mainly used in heating furnace, soaking pit and iron ditch and other thermal equipment, and display the superiority. However, its normal temperature and pressure strength is low, and the dry strength is not high. To this end, in the preparation of clay with refractory cast material, mixed with a small amount of advanced refractory superfine powder and other additives, made of high strength clay bonded with refractory. In addition, it is also developed to combine with the light of the light refractory, and can be used directly in the working layer of the flame furnace.