煤粉的分形特征及其对水煤浆级配的影响

为进一步研究分形理论与煤粉粒度级配的相关性,运用分形理论分析了张家峁煤矿水煤浆厂不同粒度煤粉的粒径分布特性,利用激光粒度分析仪测试不同中位径煤粉的粒径分布曲线,通过作图计算发现lnyV(r)-lnr有很好的线性关系,呈现分形特征,分形维数在2.3以下。对水煤浆级配的两种经典模型Alfred模型、Rosin-Rammler模型进行分形分析,分形维数在2.5以上。将中位径为6μm的煤粉样品分别与中位径29μm和90μm的煤粉等比例级配,其结果分形维数也都在2.5以上,高于未级配煤粉分形维数,因此分形维数是级配的特征参数。级配过程提高了煤粉的分形维数,通过测定煤粉的分形维数可评判级配的好坏,以及粒度分布是否接近理论模型。

Fractal characteristics of pulverized coal and its effect on PSD of coal-water slurry

To further study the correlation between fractal theory and coal particle size gradation，the different size of coal particle size distribution from the Coal Slurry Plant of the Zhangjiamao Mining was researched by fractal theory.The median diameter of pulverized coal to the particle size distribution curves could be identified by using laser particle size analyzer.By fitting curve linear of ln yV(r)-ln r，the fractal characteristics are showed，and the fractal dimension is lower than 2.3.For the Alfred and Rosin-Rammler model，the fractal dimension is both above 2.5.The median particle diameter of 6 μm samples of pulverized coal were mixed with the median diameter of 29 μm and 90 μm，the results are both above 2.5，higher than the pulverized coal without PSD.Therefore，the fractal dimension is characteristic parameters for the PSD processing.The process of PSD improves the fractal dimension of pulverized coal.By measuring the fractal dimension，the particle size distribution of pulverized coal can be judged good or bad-graded，and whether close to the theoretical model or not.