基于Rietveld法硅酸盐水泥熟料定量结果的准确性分析∗

摘要

The four main monominerals of Portland cement clinkers were prepared through solid-state reactions and then mixed artificially to form clinkers.Accuracy in Rietveld quantitative phase analysis of these clinkers was studied by fitting analysis of X-ray diffraction pattern using Topas software.The results show that all of the correction factors,fc,are about 1±0.07,which indicates that the monominerals do not exist gross amorphous errors.Quantitative results obtained from Rietveld refinements of different artificial clinkers show the sums of absolute errors (SAE)are all about 5%.But the relative errors vary significantly from different phases.They are about 5% in the high-content phases (>25%)and between 8.3% and 16.8% in the low-content phases (<20%).Compared with quantitative results obtained from Rietveld refinements of step scanning (5 s/step)and continuous scanning (2°/min)patterns,the refinements of former type have high precision value for the relative error analysis (SRE),especially for the SRE of C3 S and C2 S (about 4% lower than that of continuous scanning (2°/min)patterns).But the sums of absolute error (SAE)in the same sample are almost identical,about 1% of difference value of SAE.%通过固相反应所制备的熟料单矿物用于人工配制不同硅酸盐水泥熟料体系,利用 Topas 软件对其X射线衍射图谱进行拟合分析,研究 Rietveld 定量结果的准确性.结果表明,所制备的4种单矿物精修后的相关系数fc 均为1±0．07,说明不存在显著的无定型相等样品误差以及 Rietveld 精修的计算误差. Rietveld法定量分析所配制的不同熟料体系,各相绝对误差加和(SAE)约为5％.同一熟料体系中相对含量高的矿物(＞25％),其定量结果的相对误差约为5％；相对含量低的矿物(＜20％),其定量结果的相对误差介于8．3％~16．8％之间.比较不同扫描方式的Rietveld定量结果,虽然从相对误差分析显示步进扫描(5 s/step)的准确度高于连续扫描(2°/min),尤其是C3 S和 C2 S 两种矿物的相对误差和(SRE)较2°/min的连续扫描低约4％,但两种扫描方式的 SAE 并无明显差异,各样品的SAE的差值均在1％左右.