The main crystal phase of magnesia brick is periclase, which has the typical characteristics of general alkaline refractory products, but has poor thermal shock resistance. Thermal storage brick

Magnesium bricks are divided into fired magnesium bricks non-fired magnesium bricks. The fired magnesium bricks are divided into silicate bonded magnesium bricks, direct bonded magnesium bricks re-bound magnesium bricks. Non-burning magnesia bricks are divided into chemically bonded magnesium bricks asphalt bonded magnesium bricks.

The raw material of magnesia brick is mainly magnesite, whose basic component is MgCO3, which is calcined at high temperature then broken to a certain particle size to become sintered magnesia. Magnesia is widely used as furnace repair materials ramming materials. Magnesia with less impurities (ω (CaO) <2.5%, ω (SiO2) <3.5%) is used as raw materials for making magnesia bricks. China's magnesium ore reserves output are among the highest in the world.

Magnesium bricks are divided into sintered magnesium bricks chemically bonded magnesium bricks according to their production processes. The sintered magnesia brick is made of dead-burned magnesia with appropriate particle size ratio, brine (MgCl2 aqueous solution) sulfite pulp waste liquid are used as binders. It is pressure-molded fired at a high temperature of 1550 ~ 1650 ℃. The chemically bonded magnesia brick does go through the firing process. After the sintered magnesia is prepared according to the particle size ratio, an appropriate amount of mineralizer binder is added, the compacted product is dried to form the finished product. The strength of chemically bonded magnesium bricks is low, the performance is as good as that of sintered magnesium bricks, but the price is cheaper than half of the price of sintered magnesium bricks. It is used in areas with less demanding performance, such as the bottom of heating furnaces soaking furnaces.

Magnesium brick is an alkaline refractory material, which has a strong resistance to alkaline slag, but cannot resist the erosion of acidic slag. At 1600 ° C, it can react with silicon brick, clay brick even high alumina brick. The fire resistance of magnesia brick is above 2000 ℃, but its load softening point is only 1500 ~ 1550 ℃. Moreover, the temperature interval the beginning of softening to 40% deformation is very small, the thermal stability of magnesium bricks at only 30-50 ° C is also poor, which is an important reason for the damage of magnesium bricks.