The invention relates to large or specific compound
magnesium-aluminum
spinel products with the formula of 48 to 56 percent of 5-1mm
magnesium-aluminum
spinel, 12 to 22 percent of 1-0.088mm
magnesium-aluminum
spinel, 16 to 25 percent of magnesium-aluminum spinel with d90 less than 0.088mm, 3 to 6 percent of magnesium-aluminum spinel with d90 less than 0.010mm, 3 to 15 percent of beta
alumina powder with d95 less than 0.020mm, 2 to 6 percent of hydratable
alumina, 1 to 5 percent of magnesium
promoter, 0.05 to 0.4 percent of external efficient water reducing agents (polycarboxylic acid plus sulfonation naphthaldehyde
polymer plus sulfonation
melamine polymer), 1 to 6 percent of latex of the
system of external
polyacrylic acid and 1 to 6 percent of external water. The magnesium-aluminum spinel composite combined
refractory has the following chemical compositions: 72 to 87 percent of Al2O3, 12 to 27 percent of MgO, 0.2 to 1.5 percent of Na2O and 0.1 to 0.5 percent of SiO2. The raw materials are weighed according to the ratios, and are mixed, molded and maintained to make billets, and then are subjected to the processes of
drying, firing at the temperature of 1430 to 1650 DEG C and inspection and the like so as to make products of large or specific compound magnesium-aluminum spinel
refractory. The magnesium-aluminum spinel product has excellent manufacturing performance and excellent performances of high-
temperature resistance,
erosion resistance and
creep resistance. As the products are casted and moulded, large and specific products can be produced.