熔盐法制备针状莫来石晶体的研究

Study on Preparation of Acicular Mullite Crystal by Molten Salt Method

本文采用Al2(SO4)3.18H2O和SiO2为原料,以K2SO4,Na2SO4为熔盐,用熔盐法合成了针状莫来石晶体。研究了不同合成温度、熔盐用量和保温时间对合成莫来石晶体的影响,分析了熔盐法合成针状莫来石的反应机理。研究结果表明:以K2SO4为熔盐,熔盐与反应物总量质量比为1∶1,合成温度为1000℃,保温时间为3 h时可以合成针状莫来石晶体,针状莫来石的生成符合L-S液固生长机理。

The acicular mullite was synthesized by molten salt synthesis method using Al2（SO4）3·18H2O, SiO2 as raw materials and K2SO4, Na2SO4 as flux of molten salt. The effect of synthesis temperature, amount of molten salt and soaking time on mullite crystal was investigated. The growth mechanism of synthesis acicular mullite crystal was also analyzed. The results show that acicular mullite can he synthesized by using K2SO4 as molten salt, the weight ratio of molten salt and reactant materials is 1： 1, the synthesis temperature is 1000 ℃ and soaking time is over 3 h. The growth mechanism of acicular mullite is accord with the liquid-solid mechanics.