氢氧化铝活化对水热法制备勃姆石的影响

采用氢氧化铝粉体为原料，活化后通过水热法制备勃姆石。研究了氢氧化铝活化对勃姆石颗粒尺寸的影响，并讨论了相关机理。研究结果表明：未活化氢氧化铝水热反应所得产物颗粒粒径为2μm，经过加热（160～220℃）活化的氢氧化铝，水热反应所得产物的颗粒粒径在0.3～2μm变化。对活化氢氧化铝和水热反应中间产物进行表征，由结构分析推测作用机制：氢氧化铝加热活化过程中生成少量勃姆石，这些勃姆石在氢氧化铝水热反应转化为勃姆石（AlOOH）的过程中成为晶种，活化温度升高和活化时间延长，勃姆石晶种数量增加，氢氧化铝水热反应所得产物的颗粒粒径减小，并且加快了水热反应速率。该工作有望提供一种氢氧化铝水热法制备勃姆石的新途径和相关基础理论。

Effect of gibbsite activation on preparation of boehmite by hydrothermal method

Boehmite was prepared by hydrothermal method with gibbsite powder as raw material after activation.The effect of gibbsite activation on boehmite grain size was investigated，and the action mechanism was discussed.The results showed that by using unactivated gibbsite as raw materials，the particle size of boehmite was about 2 μm and the particle size of boehmite changed in the range of 0.3 μm to 2 μm by using activated gibbsite（treated under 160~220 ℃） as raw materials.The activated aluminum hydroxide and hydrothermal reaction intermediates were characterized.The mechanism of action from structural analysis was inferred:A small amount of boehmite was formed during activation process.These boehmite became crystal seeds during the hydrothermal conversion of Al（OH）₃ to AlOOH.With increase of activation temperature or activation time， the number of boehmite crystal seeds was increased，the particle size of hydrothermal products（boehmite） was reduced，and hydrothermal reaction rate was speeded up.This work was expected to provide a new route for the preparation of boehmite and a theoretical basis.