Refractory castables are widely used in high-temperature fields mainly for their convenient construction performance and use performance. Compared with refractory bricks of the same material, they greatly shorten the construction period, improve the construction site environment, improve maintenance efficiency and reduce costs. The uses and construction methods of refractory castables made of different materials are different.

Examples of the uses of refractory castables:

In places that are corroded by molten iron, molten steel and slag and have high working temperatures, such as steel spouts, steel ladles and blast furnace bodies, iron spouts, etc., refractory castables made of high-quality granular and powdered materials with high alumina content and good sintering, which are combined with low-calcium and pure high-alumina cement, can be used.

Phosphate refractory castables can be widely used in heating furnaces and soaking furnaces for heating metals, as well as in coking furnaces and cement kilns that are in direct contact with materials.

In some parts of metallurgical furnaces and other containers that are in direct contact with slag and molten metal, the use of high-quality phosphate refractory castables for repairing also has good results.

In some parts where the working temperature is not very high but high wear resistance is required, it is more appropriate to use phosphate refractory castables.

If corundum refractory materials are used to make refractory castables, they generally have good results when used in a reducing atmosphere.

Regardless of which castable is used to cast the lining, it should be baked before the first use so that the physical water and crystal water in it are gradually removed, and a certain degree of sintering is achieved, so that its volume and certain properties reach a stable state during use.

The baking system has a great influence on the service life. The basic principle of the baking system should be that the heating rate corresponds to the possible dehydration and other phase changes and deformations. In certain temperature stages where the above changes occur rapidly, the temperature should be slowly raised or even kept warm for a considerable time.

If it is improperly baked or the temperature is quickly raised without baking and put into use, it is very easy to produce serious cracks, or even loose collapse, especially in thicker parts where explosions may occur.

There are several construction methods for refractory castables:

① Add water and directly cast into an integral lining, such as high-aluminum castables and low-cement castables. A mold needs to be set up.

② According to the complexity of the casting site, the site that cannot be cast can be self-flowing. The commonly used low-cement self-flowing castable does not require a mold;

③ Use the coating method for construction, no mold is required, and a thinner lining is applied, which is more time-saving and labor-saving. Such as refractory coating;

④ Use the ramming method to fill the material into the furnace shell, and use the ramming tool to vibrate strongly to obtain a strong density, which can be directly put into production and form a ceramic structure at high temperature;

⑤ Use the spraying method for construction, which requires the use of spraying equipment to directly spray the mixed material to the construction site.

⑥ Directly press the material into the construction site, also known as refractory pressurized material, such as foam mud for blast furnace tapping;

⑦ Directly cast into prefabricated parts at the manufacturer, and build and construct at the construction site, called castable prefabricated parts or refractory prefabricated parts, etc.

The main application areas of refractory castables: steel industry, building materials industry, non-ferrous metallurgy industry, petrochemical industry, power industry, high-temperature machinery industry, thermal equipment, etc., can all use refractory castables as lining materials, and their use effect is better than refractory bricks and their service life is longer.