Abstract: In order to further improve the performance of Al₂O₃-SiC-C castables for the blast furnace trough,Al₂O₃-SiC-C castables were prepared using brown corundum,dense corundum,silicon carbide,calcium aluminate cement,ball pitch,α-Al₂O₃ micropowder,SiO₂ micropowder,etc.as the main raw materials,heat treating at 1 450 ℃.On the basis of the traditional anti-oxidants (Al powder and Si powder),2 mass% spodumene powder with different particle sizes (≤0.076,≤0.048 and ≤0.038 mm,respectively) was added as the anti-oxidant.The effect of the spodumene particle size on the properties of the castables was studied.The results show that with the addition of spodumene and the reduction of the particle size,for the samples after heat treatment,the amount of residual silicon carbide decreases,the apparent porosity decreases significantly,and the hot performance and oxidation resistance increase significantly.However,when spodumene with small particle sizes is added,more SiC whiskers with larger length-diameter ratios are generated in the samples,which significantly improves the mechanical properties of the samples.Adding spodumene with the particle size ≤0.038 mm into Al₂O₃-SiC-C castables can significantly improve the oxidation resistance and comprehensive properties.

Key words: alumina-silicon carbide-carbon castables, spodumene, silicon carbide whiskers, oxidation resistance

摘要： 为了进一步改善高炉出铁沟用Al₂O₃-SiC-C浇注料的性能,以棕刚玉、致密刚玉、碳化硅、铝酸钙水泥、球沥青、α-Al₂O₃微粉、SiO₂微粉等为主要原料,在传统抗氧化剂(Al粉和Si粉)的基础上,分别加入2%(w)不同粒度(粒度分别为≤0.076、≤0.048和≤0.038 mm)的锂辉石粉为抗氧化剂,经1 450 ℃热处理制备了Al₂O₃-SiC-C浇注料,研究了锂辉石粒度对其性能的影响。结果表明:随着锂辉石的添加及粒度的减小,热处理后试样残留碳化硅的量减小,显气孔率显著降低,高温性能和抗氧化性能显著提高;但当加入粒度较小的锂辉石时,试样中的SiC晶须生成量较多,并且具有更大的长径比,这明显改善了试样的力学性能。在Al₂O₃-SiC-C浇注料中加入≤0.038 mm的锂辉石,可以显著改善试样的抗氧化性和综合性能。

关键词: Al₂O₃-SiC-C浇注料, 锂辉石, SiC晶须, 抗氧化性