ρ-Al_2O_3对刚玉尖晶石浇注料性能的影响研究

Effect of ρ-Al_2O_3 addition on performance of corundum spinel castables

通过一系列试验,研究了ρ-Al_2O_3对刚玉尖晶石浇注料综合性能的影响。结果表明:ρ-Al_2O_3能够促进铝酸钙水泥的膨胀效应反应,抵消水化产物脱水造成的收缩,能够明显提高铝酸钙水泥结合浇注料试样的中温强度(800℃)和降低永久线变化率。当ρ-Al_2O_3含量为7wt.%时,中温强度最高,并大于110℃烘干强度;在无铝酸钙水泥和硅微粉添加的条件下,仅采用ρ-Al_2O_3做结合剂,其试样的中温强度较低,高温(1400℃)强度不稳定;对于低硅或无硅含量要求的浇注料,或中温下要求尺寸变化小、强度高的浇注料,可采用铝酸钙水泥和ρ-Al_2O_3配合使用的方式,但在大量使用时ρ-Al_2O_3的加入量不宜超过3wt.%。

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-Al2O3 could promote the expansion effect reaction of calcium aluminate cement and offset the dehydration shrinkage of hydration products. When the content of ρ-Al2O3 was 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.