Abstract:

By using alumina hollow balls with grain sizes of 5~3mm, 3~2mm, 2~1mm and 1~0.2mm as raw material and adding SiO2 micro-powder the gel bonded alumina hollow ball castable is formed. The effect of pre- synthesized magnesia-alumina spinel on the properties of gel bonded alumina hollow ball castable is studied. The property determination of spinel specimens adding different amounts of spinel is  carried out with various kinds of refractory product determining and analytical equipment and instrument.In combination with the theoretical analysis done with magnesia-alumina-silica phase diagram, the result shows that the addition of spinel promotes the sintering function of corundum phase in castable, raises the cold crushing strength and apparent porosity of gel bonded alumina hollow ball castale and reduces the bulk density of it. Spinel has the strengthening function to the matrix of the gel bonded alumina hollow ball castable and is favorable to improve the thermal shock resistance of it.