应用X射线衍射-红外光谱等技术研究滑石在机械力研磨中的形貌和晶体结构变化及影响机制

滑石的颗粒粒径、形貌、晶型等对其应用的实效性、终端产品的性能产生极大影响,目前主要研究其表面改性,而有关微观形貌及晶体结构研究较少。本文利用X射线荧光光谱、X射线衍射分析、红外光谱、粒度分析仪结合高分辨场发射扫描电镜(FE-SEM)技术对辽宁滑石粉在高强度机械力研磨作用下的微形貌和晶体结构变化特征进行系统研究。结果表明滑石粉原矿混合物中MgO与SiO2的分子个数比约为0.45,该数值明显低于纯滑石粉晶体中MgO与SiO2的分子个数比0.75。此类滑石为典型的单斜晶系,研磨作用使滑石粉由晶态转变为非晶态结构,其层状结构的有序化和键合作用发生了明显的变化。滑石粒度随研磨时间变化呈现减小-增大-减小的循环过程。研磨后粉体形貌存在差异,细化的小颗粒粉体因团聚而呈"准球体",且随着研磨的进行出现细化-团聚-细化的反复过程。此结论对于滑石的深加工与应用及其相关矿物粉体的研究具有一定的参考价值。

Applicaltion of X-ray Diffraction and Infrared Spectroscopy Techniques for Revealing Effect Mechanism of Mechanical Grinding on the Morphology and Crystalline Structure of Talc

The particle size, morphology and crystal type of talc have important effects on its effective application and the function of the end products. Current study of talc focuses mainly on the surface modification, but there are few studies on their morphology and crystalline structure. The changes of morphology and crystalline structure of talc from Liaoning induced by strong mechanic grinding were investigated using X-ray Fluorescence Spectrometry (XRF), X-ray Diffraction (XRD), Infrared Spectroscopy, Particle Size Analyzer and Field Emission Scanning Microscopy (FE-SEM). The results show that the MgO/SiO₂ molar ratio is 0.45, which is lower than the calculated value (0.75) for ideal talc. The crystalline structure has been destroyed after prolonged grinding. Namely, the structure of talc is changed from a crystalline state into an amorphous state after grinding. With the increase of grinding time, the particle size repeats diminution, enlargement, diminution processes. The morphology of powder was changed after grinding, which gradually changed to be a torispherical shape, and then had a refinement-reunion-refinement process. The conclusion of the circulation change has an important guiding significance and reference value for the further processing and application of talc and the study of related mineral powders.