蓝晶石基莫来石粒度对硅莫砖性能的影响

Effect of particle size of kyanite-based mullite on properties of SiC-mullite brick

为拓宽蓝晶石基莫来石新型耐火原料的应用,以60%(w)的高铝矾土熟料、15%(w)的碳化硅、5%(w)的广西白泥、20%(w)的蓝晶石基莫来石为原料,机压制备了230 mm×114 mm×65 mm的硅莫标砖,在隧道窑中于1 410℃保温4 h烧成。研究了分别用三种粒级(3~1、≤1和≤0.074 mm)的蓝晶石基莫来石等量替代同粒级的矾土熟料后对硅莫砖性能尤其是抗热震性的影响。结果表明:1)加入蓝晶石基莫来石粒度越小,试样抗热震性越好,热膨胀率越小,但相应的荷重软化温度越低;2)控制好合适的蓝晶石基莫来石粒度级别和加入量,可以显著改善硅莫砖的抗热震性,同时保持其常温和高温性能不下降。

In order to research the application of kyanite-based mullite,the SiC-mullite standard bricks （230 mm × 114 mm ×65 mm） were prepared using bauxite clinker （60 mass% ） ,SiC （15 mass% ） ,Guangxi white clay （5 mass%） and kyanite-based mullite （20 mass%） as starting materials, mechanical pressing, and firing at 1 410 ℃ for 4 h in a tunnel kiln. The properties of SiC-mullite bricks,especially the thermal shock resistance,were studied after replacing the bauxite clinker using equivalent kyanite-based mullites with the same particle size （3 - 1, ≤ 1, and ≤0. 074 mm）. The results show that： （ 1 ） when the particle size of the kyanite-based mullite decreases,the thermal shock resistance of the specimens gets better,and the thermal expansion rate decreases, but the refractoriness under load decreases; （2） optimizing particle sizes and addition of kyanite-based mullite is significant to improve the thermal shock resistance and keep the performances at room and high temperatures of SiC-mullite bricks.