With the continuous development of industrial demand and technical research, the variety of lightweight refractory castables for magnesia carbon brick listed companies has been continuously expanded, and the scope of use has also been greatly expanded. In terms of variety classification; generally, it is classified according to the variety, production method, binder type and performance level of lightweight aggregates. Commonly used are lightweight bricks, porous clinkers, hollow balls, and Lightweight refractory castables such as ceramsite and expanded perlite. In terms of the scope of use, it has evolved from being a masonry material that can only be used as a heat insulation layer for high-temperature furnaces, to a lightweight refractory castable that can now be used to build working linings for flame furnaces below 1800 ℃. For example, in the soaking section and heating section of a steel rolling heating furnace with a furnace temperature of 1400 ℃, a lightweight refractory castable with a bulk density of 1.5 to 1.6 g/cm3 is used for the casting of the working lining. The service life has exceeded 2 years. A good energy saving effect. However, the quality of commonly used lightweight refractory castables needs to be further improved.
Construction and maintenance of lightweight refractory castables
The construction of lightweight refractory castables was carried out on the inner wall of the flue with severe damage to the gas producer. In the specific construction process, the damaged inner lining was first removed. After the cleaned, riveting pieces were arranged on the inner wall of the metal flue according to the original design requirements, and the construction process of smearing and ramming was used to complete the construction of the flue lining. It can be seen from the construction process that the developed lightweight refractory castable has excellent construction performance. After construction, the lining surface is smooth and smooth. During the natural curing process, the inner lining solidified smoothly, and no cracks occurred on the surface.
After construction and maintenance, it was put into production and practical application. After on-site observation and testing, the flue is operating normally. The surface temperature is uniform, indicating that the thickness of the inner lining is uniform, and there is no partial structural peeling of the inner lining under the condition of high temperature flue gas washing. After one year of practical application, we observed that the flue lining was intact by taking advantage of the annual repair time. Achieved the expected application effect. At present, the flue has been used for two years, and no obvious lining peeling and erosion have been found. No problem of metal structure deformation of the flue has been found, and the purpose of greatly extending the service life of the flue has been achieved.
