This product is made of magnesia with good grain gradation by adding appropriate chemical binder and roasting after mixing, forming and drying. It has high refractoriness, good alkaline slag resistance and high starting temperature of load softening. It is mainly used in basic open hearth, bottom and wall of steel making, oxygen converter, ferroalloy smelting furnace and non-ferrous metal furnace. High temperature tunnel kiln, lining of calcined magnesia brick and cement rotary kiln, hearth and wall of heating furnace, grid brick of regenerator of glass kiln, etc.