在煤系共伴生矿产的综合利用和碳中和背景下，煤系石墨日益受到国内外学者的重点关注。XRD光谱分析作为研究分子有序程度和测定煤微晶结构的重要表征手段之一，对揭示碳微晶排列方式的有序性与煤石墨化程度之间的关系具有重要意义。为了更加科学、快速、有效的获取煤的XRD相关指标参数，不断完善煤系石墨的评价指标体系，以淮北煤田7对生产矿井的系列变质程度煤为研究对象，借助煤质分析、煤镜质体反射率和XRD等实验手段，研究不同分峰拟合方法和不同样品前处理方法对XRD光谱参数的影响，探讨基于XRD光谱分析的煤系石墨评价指标的合理确定方法及响应规律。研究表明；①不同分峰拟合方法对煤系石墨的评价等级结果影响较大，相对基线是否去除而言，底背是否扣除对实验结果的影响更为明显；②是否考虑（γ）峰对实验结果影响较大，直接影响了样品石墨化程度的划分与鉴定结果；③通过对不同原煤和标准Si粉配比条件下的XRD光谱曲线分析，得出在原煤/SiO₂≈3∶1的质量比条件下，采用内标法可以有效确定原煤样品（002）峰的2θ值，实验效果与脱矿物方法相当；④V_daf和H/C可推荐为淮北煤田煤系石墨鉴定的主要煤质参数指标，La、La/Lc和d₀₀₂指标可推荐为淮北煤田煤系石墨鉴定的主要结构参数指标，其中V_daf＜20%、H/C＞0.035、La＜4 nm、La/Lc＜1和d₀₀₂＜0.344 nm可作为淮北煤田煤变质作用进入半石墨化阶段的临界标志。上述研究成果为实现淮北煤田煤系石墨评价指标优选和鉴定体系的构建提供了参考依据。

Under the background of comprehensive utilization and carbon neutralization of coal-series associated minerals, coal-series graphite has attracted more and more attention from scholars at home and abroad. As one of the important characterization means to study the degree of molecular order and determine the structure of coal microcrystals, XRD spectrum analysis is of great significance to reveal the relationship between the order of carbon microcrystal arrangement and the graphitization degree of coal. In order to obtain the XRD related index parameters of coal more scientifically, quickly and effectively, and constantly improve the evaluation index system of coal-series graphite, taking 7 pairs of metamorphic coals in Huaibei coalfield as the research object, with the help of coal quality analysis, vitrinite reflectance and XRD, the effects of different peak fitting methods and different sample pretreatment methods on XRD spectral parameters were studied, and the effective determination method and response law of coal-series graphite evaluation index based on XRD spectral analysis were discussed. Research shows that; ① Different peak fitting methods have great influence on the evaluation results of coal-series graphite, and whether the bottom back is deducted has more obvious influence on the experimental results than whether the baseline is removed; ② Whether the (γ) peak is considered has a great influence on the experimental results, which directly affects the classification and identification results of the graphitization degree of the samples; ③ By analyzing the XRD spectrum curves of different raw coal and standard Si powder ratios, it is concluded that under the mass ratio of raw coal/SiO₂ ≈3∶1, the 2θ value of (002) peak of raw coal sample can be effectively determined by internal standard method, and the experimental effect is equivalent to that of demineralization method. ④ V_daf and H/C can be recommended as the main coal quality parameters, while La, La/Lc and d₀₀₂ can be recommended as the main structural parameters. Among them, V_daf < 20%, H/C > 0.035, La < 4 nm, La/Lc < 1 and d₀₀₂＜0.344 nm can be used as the critical marks for the coal metamorphism in Huaibei coalfield to enter the semi-graphitization stage. The above research results provide a reference for the optimization of evaluation index and the construction of identification system of coal-series graphite in Huaibei coalfield.