The invention relates to an alkaline composite 
refractory brick, which consists of a 
periclase-
magnesium aluminate spinel flame retardant 
coating and a 
periclase-
forsterite thermal-protective 
coating. The proportion of the alkaline composite 
refractory brick is as follows: 1) the proportion of the 
flame retardant 
coating is as follows: 29 to 48 percent of 
magnesite of between 5 and 1 
millimeter, 7 to 16 percent of the 
magnesium aluminate spinel of between 3 and 1 
millimeter, 6 to 20 percent of the 
magnesite of between 1 and 0.088 
millimeter, 0 to 4 percent of desilicated zirconia granules of between 0.4 and 0.088 millimeter, 16 to 25 percent of the 
magnesite of less than 0.088 millimeter, 0 to 10 percent of magnesite micropowder of less than 0.020 millimeter, 0 to 5 percent of desilicated zirconia micropowder of less than 0.020 millimeter, 0 to 3 percent of 
calcium carbonate micropowder less than 0.020 millimeter, 0 to 6 percent of 
lanthanum oxide of less than 0.020 millimeter, and 0 to 0.3 percent of additional water 
reducing agent (sulfonated naphthaldehyde 
polymer, sulfonated 
melamine polymer and polycarboxylic acid or 
sodium salt thereof); and 2) the proportion of the thermal-protective coating is as follows: 0 to 20 percent of the magnesite of between 3.2 and 1.0 millimeter, 35 to 45 percent of the 
forsterite of between 3.2 and 1.0 meter, 5 to 15 percent of the magnesite of between 1.0 and 0.088 millimeter, 5 to 15 percent of the 
forsterite of between 1.0 and 0.088 millimeter, and 30 to 40 percent of 
grinding powder of the magnesite and the forsterite of less than 0.088 millimeter. The material has the advantages that the material improves the 
erosion resistance of the 
flame retardant coating by micropowder technology, and allows the 
sintering temperature of the flame retardant coating to be matched with that of the thermal-protective coating, thereby producing the 
periclase-
magnesium aluminate spinel alkaline composite 
refractory brick which has excellent.