基于Rietveld精修法的水泥熟料物相定量分析

Quantitative Analysis of Cement Clinker by Rietveld Refinement Method

基于Rietveld精修法,通过Topas软件对水泥熟料的实验室X射线衍射(XRD)图谱进行拟合,分别研究晶体结构模型组合、精修区间和XRD扫描设定对熟料定量精修结果的影响.结果表明:多晶型晶体结构模型组合参与Rietveld定量精修可获得更为准确的矿物组成结果.对于实验室XRD图谱,选取2θ=(25°,70°)的精修区间即可满足定量精修的准确度.对于XRD扫描设定的研究表明,图谱的信噪比(有效counts值)较分辨率对Rietveld定量精修结果的影响更大;随着连续扫描速度的提高,Rietveld定量精修结果的误差逐渐增大,为保证定量精修结果的准确性和精确性,连续扫描的临界速度取2(°)/min.

Effects of crystal structure model combination, refinement range and scanning setting of X-ray diffraction （XRD） on quantitative results of cement clinker were investigated by Rietveld method with Topas software. Results show that an important prerequisite for the accurate Rietveld quantitative phase analysis of clinker is to prepare the suitable and matched crystal structure model combination involved in the refinement. In order to guarantee the accuracy and precision in quantitative analysis, the minimum range of laboratory XRD data collection should be 2θ=（25°,70°）. XRD scanning settings show that the ef- fective counts of diffraction pattern has greater influence than resolution on quantitative refinement of clinker. With increase of scanning speed of continuous scanning type, the errors of Rietveld quantitative results of clinker become more obvious. For quantitative accuracy, the critical scanning speed of continu- ous scanning type should be 2（°）/min.