Abstract: An experimental roller ball milling system was established to investigate the co-grinding and co-combustion characteristics of herbal residues (HR) and lignite. The effects of HR blending ratio and moisture content on the average particle size of the mixed materials were systematically examined. Thermogravimetric analysis (TGA) was employed to study the combustion behavior of HR, lignite, and their blends with different blending ratios, and the combustion kinetic parameters were determined using the Coats-Redfern model. The results demonstrated that when the HR blending ratio was below 50wt%, the particle size of the ground materials decreased with increasing HR content. For HR blending ratios exceeding 50wt%, low-moisture HR (5%~10%) exhibited superior grindability compared to lignite, resulting in further particle size reduction. In contrast, high-moisture HR (>10%) absorbed water, leading to increased fiber flexibility and greater grinding difficulty, which consequently caused an increase in particle size. The average particle size was found to increase with moisture content, with HR showing the most significant growth rate. Field emission scanning electron microscopy observations of five mixed powder samples confirmed both the promoting and inhibiting effects during co-grinding. At HR blending ratios of 10wt% and 30wt%, lignite and HR particles showed indistinguishable morphology and excellent mixing uniformity. TGA revealed that HR possessed lower activation energy and superior burnout characteristics compared to lignite. The incorporation of HR effectively introduced an ignition source that initiated combustion at lower temperatures. The released heat elevated local temperatures of the mixed fuel, thereby reducing the ignition temperature threshold and significantly improving ignition performance. The optimal combustion efficiency was achieved at an HR blending ratio of 30wt%. However, with rising moisture content, the TG curves of mixed fuels shifted toward higher temperature regions, weakening the promoting effect of HR on lignite combustion and increasing the burnout temperature of mixed samples. This study provides theoretical guidance for the resource utilization of HR and the development of co-grinding and co-combustion technology for HR-lignite mixtures.

Key words: herbal residue, lignite, particle size distribution, co-combustion, combustion characteristics

摘要： 针对中药渣与煤的混磨混燃过程，本工作搭建了滚筒球磨实验系统，研究了中药渣掺混比和含水率对混合物料平均粒径的影响，同时采用热重分析法研究了中药渣、褐煤及其不同掺混比例混合物的燃烧特性，并基于Coats-Redfern模型分析了其燃烧动力学参数。研究结果表明，当中药渣掺混比小于50wt%时，磨后物颗粒粒径随中药渣掺混比增加而减小，且颗粒混合均匀度较高；当中药渣掺混比大于50wt%时，低含水率(5%~10%)中药渣较褐煤更易粉碎，磨后物颗粒的平均粒径随中药渣掺混比增加而减小，高含水率(>10%)中药渣的纤维成分吸收水分，柔韧性增加，研磨难度增加，磨后物颗粒粒径随中药渣掺混比增加而增加。与褐煤相比，中药渣在燃烧过程中的反应活化能更低，具有更好的燃烬特性；中药渣的加入显著改善了混合燃料的着火性能，当掺混比为30wt%时，混合燃料燃烧效果最好。而随着含水率增加，相同中药渣掺混比混合燃料的TG曲线整体向高温区偏移，中药渣对褐煤燃烧的促进作用降低，混合样品的燃烬温度升高。本研究可为中药渣的资源化利用提供理论参考。

关键词: 中药渣, 褐煤, 粒径分布, 共燃, 燃烧特性