Bao Shengzhong, Yang Jianhong, Li xiaoxing, Li zhiyuan, Tang Xinping
(Zhengzhou Non-ferrous Metals Research Institute Co.Ltd of Chalco, zhengzhou 450041, Henan, China)
Abstract: Through a series of tests, the effects of ρ-Al2O3 on comprehensive properties of corundum spinel castable were studied. The results showed that ρ-Al2O3 could significantly reduce permanent linear change rate of calcium aluminate cement binding castable specimens under 800 ℃ and improve mid temperature strength. That was because ρ-Al2O3could promote the expansion effect reaction of calcium aluminate cement and offset the dehydration shrinkage of hydration products. When the content of ρ-AAl2O3was 7wt.%, the mid temperature strength was highest and higher than drying strength at 110 ℃. Under the condition of neither calcium aluminate cement nor silica fume were added in the corundum spinel castable with only ρ-Al2O3 as binder, both the mid temperature(800 ℃) and high temperature(1400 ℃) strength of specimens were low and instability. For low or no silicon content castable, or castable required small size change rate and high mid temperature strength, calcium aluminate cement and ρ-Al2O3 could be used complexly, but the amount of ρ-Al2O3 addition should not be excess 3wt.% in massive use.
Key words: corundum castable; spinel; ρ-Al2O3 ; calcium aluminate cement; middle temperature strength; Application performance.