Introduction to performance characteristics of magnesia carbon brick
(1) Good performance;
(2) Carbon material is difficult to be wetted by slag and molten steel, and magnesia has high fire resistance and alkaline property;
(3) The thermal conductivity of graphite is 229w / m * k at 1000 ℃, and that of MgO is 24.08w/m * k at 1000 ℃. The mechanical strength of graphite increases with the increase of temperature;
(4) High temperature creep is low.
Magnesia carbon brick for converter is made of fused (or sintered) magnesia and graphite as main raw materials, adding proper amount of antioxidants, and phenolic resin as binder. It is produced by mixing, molding and heat treatment. MgO-C brick not only keeps the advantages of carbon refractory, but also completely changes the inherent defects of the former alkaline refractory, which has poor spalling resistance and is easy to absorb slag. The application effect of MgO-C brick in converter steelmaking shows that in the future development of metallurgical industry in China, MgO-C brick will have an important strategic significance. It will greatly promote the development and popularization of MgO-C brick. It will improve the life of large-scale converter in China, completely reverse the long-term low-life situation of a large number of medium and small-sized converters in China, and fully tap the production capacity of China's metallurgical equipment The role of Li Yao.
The magnesia carbon brick is made of fused magnesia: MgO > 97.5%, / SiO2 > 2, large crystallization
Flake graphite: flake graphite
Binder: thermosetting phenolic resin
Additives: Al powder, Si powder, B4C, Al Mg alloy.
Magnesia carbon brick manufacturer
The mechanism of additive action is as follows
a. The additive is prior to the reaction of carbon and oxygen;
b. The products formed after the reaction of additives make the volume expansion, such as Al2O3, Ma, SiO2, etc., to fill pores and prevent graphite oxidation.
The high temperature bending resistance of magnesia carbon brick (with anti oxidant) and Al powder in the impact zone of converter can reach 16 ~ 20MPa, but the expansion coefficient is large, the slag resistance is reduced and it is easy to peel off.
Production process: batching - molding - heat treatment
The fine magnesia powder of magnesia carbon brick should not be too fine, and it can be less than 180 mesh (0.088 mm). Too fine MgO is easy to be reduced to mg.
Magnesia carbon brick is mainly used for lining of converter, AC arc furnace and DC electric arc furnace, slag line of ladle, etc. Basic open hearth furnace, electric furnace bottom and wall, oxygen converter lining, nonferrous metal smelting furnace, high temperature tunnel kiln, calcined magnesia brick and cement rotary kiln lining, furnace bottom and furnace wall of heating furnace, checker brick of regenerator of glass kiln, etc.