The preparation of mullite whiskers based on catalytic method using inexpensive raw materials is a green and efficient method,but there is a lack of systematic study for the catalytic effect of different catalysts.In this work,mullite whiskers were synthesized at 1300 ℃ using cheap kaolin and alumina as raw materials and boron oxide was proposed as a new catalyst,meanwhile,traditional typical catalysts such as aluminium fluoride and ammonium molybdate were used for comparison.The phase composition and microscopic morphology of the whiskers were analysed by XRD and SEM,and the effects of the three catalysts(aluminium fluoride,ammonium molybdate and boron oxide)and their addition amounts on the synthesis of mullite whiskers were investigated.The results showed that the catalytic effect of aluminium fluoride was better than that of ammonium molybdate for the conventional catalysts,and the mullite whisker aspect ratio was about 10.5 with the addition of 10 wt.％aluminium fluoride.boron oxide had the best catalytic effect among the three catalysts,and the whisker aspect ratio increased gradually with the increase of boron oxide doping.When boron oxide was added at 15 wt.％,the resulting whiskers were all mullite phase and uniformly distributed,with a aspect ratio of 13.
关键词
莫来石晶须/催化剂/高岭土/氧化硼/长径比
Key words
mullite whisker/catalyst/kaolin/boron oxide/aspect ratio
维普
万方数据