Properties and uses of magnesia brick

The magnesia brick has a fire resistance of more than 2000, and the softening temperature under load varies with the melting point of the binding phase and the liquid phase produced at high temperature, but does not change greatly. The general softening start temperature of magnesium brick is 1520 ～ 1600, while the high soft magnesium boasting heavy softening start temperature can reach 1800.

 

The load softening temperature of magnesium bricks does not differ much from the collapse temperature. This is because the main phase composition of magnesium bricks is periclase.

 

But periclase crystals do not crystallize the network skeleton in the magnesia brick, but are cemented by the conjugate. In ordinary magnesia bricks, the silicate phase such as forsterite and forsterite is generally used as a combination. Although the melting point of the periclase grains constituting the magnesia brick is relatively high, some melt at around 1500. The silicate phase exists and its liquid phase has a low viscosity at high temperatures, so it reflects that the load deformation temperature and collapse temperature of ordinary magnesia bricks are not much different, but it is quite different from the fire resistance.

The load softening temperature of high-purity magnesia bricks can reach 1800, mainly due to the combination of forsterite or dicalcium silicate and the high melting temperature of the eutectic formed with MgO. The lattice strength between the crystals is large and the plastic deformation at high temperature is small, and the crystal particles are well bonded.