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›› 2006, Vol. 6 ›› Issue (5): 763-767.

• 过程与工艺 • 上一篇    下一篇

高膨胀率高质量蛭石粉体研制---II. 蛭石热膨胀过程

胡光锁,李政一,朱永平,张伟刚   

  1. 北京工商大学化学与环境工程学院
  • 出版日期:2006-10-20 发布日期:2006-10-20

Preparation of Vermiculite Powder with High Expansion and High Quality

HU Guang-suo,LI Zheng-yi,ZHU Yong-ping,ZHANG Wei-gang   

  1. College of Chemical and Environmental Engineering, Beijing Technology and Business University
  • Online:2006-10-20 Published:2006-10-20

摘要: 在对新疆尉犁蛭石膨胀机理研究的基础上,研究了在不同温度和加热速率条件下该蛭石的体积膨胀率,试图得到影响蛭石膨胀的主要膨胀工艺参数,开发新型节能膨胀技术. 研究发现,新疆尉犁蛭石的单片体积膨胀率和集合膨胀率均随温度升高而增加,但当温度超过600℃后,体积膨胀率增加缓慢. 单片体积膨胀率存在很大的离散性,说明新疆尉犁蛭石不是单一的金云母-蛭石层间矿物,而是由一系列水化程度不同的金云母组成的次生变质矿. 在引起蛭石膨胀的150~300℃温度区间内出现3个吸热峰,它们分别是由与不同阳离子结合的层间水的脱除引起的. 加热速率影响热膨胀过程,快速加热有利于制备高膨胀率的蛭石粉体. 制备的高膨胀率蛭石的层孔直径大约为100 nm,粉体的室温热导率为0.113~0.115 W/(m·K),是一种性能优良的隔热材料.

关键词: 蛭石, 膨胀, 热谱分析, 层孔材料

Abstract: Following the previous study on the expansion mechanism of vermiculite originated in Weili, Xinjiang, China, the thermal expansion of the vermiculite was investigated in this work. The results show that individual and cumulative volume expansion ratios increase with increasing of temperature. However, the effect of temperature above 600℃ can be negligible, companied with a very positive effect of fast heating rate which indicates a possibility to utilize such property for producing very high volume expansion vermiculite. Strong scattering of individual expansibility can be explained with the microstructure variation of phlogopite-vermiculite interstratification in the mineral. Thermal analysis confirms that there exist three types of crystallized water combined with metallic ions, such as Ca, Mg and Na during interstratification. Finally, very fine vermiculite powder with thermal conductivity of 0.113~0.115 W/(m·K) was produced, which may be used as high quality thermal insulation material.

Key words: vermiculite, expansion, thermal analysis, porous material