微爆法解离蛭石的工艺可行性研究

Preparation of Expanded Vermiculite by Micro-explosion

微爆解离蛭石主要通过溶剂加压浸润预处理及溶剂瞬间蒸发形成的冲击力场实现蛭石膨胀解离。结合扫描电子显微镜(SEM)、粒度和X-粉末衍射(XRD)分析,客观评价了微爆法解离蛭石工艺的可行性。结果表明,微爆处理具有粉碎和解离蛭石的双重功效;强极性有机溶剂DMF具有优于水的解离能力;微爆处理不同于热处理,对蛭石的晶体结构无破坏作用;适度提升溶剂用量有利于提升溶剂浸润程度,过大蒸汽压则压缩湮灭蛭石各类孔隙,难以实现扩展层间距的目标。

The expansion of vermiculite by micro-explosion was achieved by media solvation pretreating at high pressure and the impact brought by their instant evaporation. The feasibility of this method was proved by SEM, as well as particle size analysis and X-ray diffraction （XRD） analysis. The results showed that micro-explosion was not only good for the pulverization but also the expansion of the vermiculite. Organic medium with high polarity （DMF） gave better expansion ability than water. The most important part about this study was that different from heat treatment, which damaged the crystal structure of vermiculite, micro-explosion did no harm to it. Proper enlarge the dose of medium was helpful for the solvation, hence, good expansion effect; however, too much solvent caused overdose vapor pressure, which compressed and annihilated the ventage of vermiculite, thus the expansion was to some extent inhibited.