Refractory definition

Refractory material refer to inorganic nonmetallic materials with a refractoriness of not less than 1580 ° C.
Refractory materials are generally made of natural minerals and rocks of aluminum silicate as the main raw material. Its basic processes and certain basic characteristics are similar to those of other products of the silicate system. Therefore, refractories are listed as one of the silicate systems Product and important part of the silicate industry. Refractory product same to cement, ceramics, glass and other silicate industry has a very important position and role in the national economy.
Because it has a special performance of resistance to high temperature  in the thermal equipment, then it occupies a very important position in the development of modern industry. With the discovery and need of science and technology, the use of refractories is expanding, from metallurgy (including steel and nonferrous metallurgy, etc.), silicate (cement, ceramics, etc.), chemical, power, machinery and other industries, extended to everything High-temperature operation of the industrial and mining enterprises, the kiln (combustion kiln, molten pool, fire, crucible) and other heat parts of thermal equipment, refractories are indispensable important building structural materials. In the field of cutting-edge science (such as rockets, atomic reactors, etc.) is also an indispensable high temperature resistant materials or parts.
As the refractory material used in a variety of different heating conditions of high temperature equipment, it is subject to high temperature and other different conditions, by the complex physical and chemical reactions and damage. Therefore, the refractory material must have the following important performance.
1.Refractory material is not easy to melt when in the case of high temperature
The working temperature of modern industrial kiln furnace is generally between 1000 ~ 1800 ℃, therefore the refractory material must first be not easy to melt in this temperature.
2.Refractory material does not soften when in the case of high temperature pressure
The melting temperature of Most refractory material more than 1650 ~ 1700 ℃, but it reached the melting temperature before the deformation (softening), loss of structural strength, so the refractory not only have a high melting temperature, but also with high temperature Under the conditions of the load does not occur deformation performance.
3.Volume stability in high temperature environment
Refractory materials used in high temperature conditions, due to physical and chemical reactions within the material and make the volume changes. Most of this change in refractory material is volume shrinkage, and a few are inflated. Whether it is volume shrinkage or expansion, such as beyond a certain range can cause damage to the furnace. So the refractory material is required to have good high temperature volumetric stability.
4.Refractory product can resist the sudden change and uneven heating of temperature to avoid damage to the furnace
In the intermittent operation of the kiln, the high temperature, the rapid changes in the various parts of the masonry heat uneven, brick body will produce stress inside the material cracking, resulting in furnace damage. So the refractory material should be able to withstand the rapid changes in furnace temperature and fluctuations do not crack the performance of thermal stability.
5.Refractory can resist the erosion of slag when in the case of high temperature
in the use of the process, due to disguised contact with fuel ash, molten slag and molten metal and other effects were eroded. Therefore, the refractory material should have the ability to resist this erosion. In the use of refractory materials, according to the main requirements of the use of various refractory materials and have the characteristics of a reasonable choice.