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

Magnesia brick is an alkaline refractory material. It has strong resistance to alkaline slag, but it can not resist the erosion of acid slag. It can react with silica brick, clay brick and even high alumina brick at 1600 °C. The refractoriness of magnesia bricks is above 2000 °C, but its load softening point is only 1500~1550 °C. Moreover, the temperature interval from the beginning of softening to 40% deformation is very small, and the thermal stability of only 30~50 °C magnesia bricks is also poor, which is an important reason for the damage of magnesia bricks.

On the heating furnace and the soaking furnace, the magnesia brick is mainly used for paving the surface layer of the bottom of the furnace and the lower part of the furnace wall of the soaking furnace, which can resist the erosion of the scale.

Magnesia bricks have poor hydration resistance, easy to hydrate with water, and cracks and reduce their strength. Therefore, pay attention to moisture, rain and snow during storage and transportation.

The magnesia raw material is crushed into granules and powders, and after being compounded according to a certain ratio, the binder is added and mixed into a slurry, and then formed into a magnesia brick by molding, drying, firing, and the like. The firing temperature of ordinary magnesia bricks is generally 1500~1650 °C, and the firing temperature of high-purity magnesia bricks is as high as 1700~1900 °C.