煤粉孔隙分形结构对水煤浆性质的影响规律

用分形理论能描述具有强烈非线性特征的煤粉孔隙结构，利用氮吸附仪分析得到10种煤样的孔隙分形维数为2.572~2.722，利用Haake黏度计测量水煤浆黏度，讨论了孔隙分形、水分、氧量和可磨性指数等对水煤浆性质的影响规律，得到相关的拟合经验公式。当分形维数由2.61增大到2.643和2.698时，不同煤粉制得水煤浆的最高浓度由70.8%降低到69.2%和62.4%，而相应在剪切速率20 s-1时表观黏度则由879 mPa×s升高到1 900和2 006 mPa×s。说明随着不同煤粉的孔隙分形维数增加，比表面积和孔容积增大，导致水煤浆黏度升高和浓度降低，对成浆特性造成不利影响；而随着煤粉内在水分增加、氧量增加和可磨性指数减小，煤粉的成浆特性变差。

Impacts of Pore Fractal Structures of Pulverized Coals on Coal Water Slurry Properties

The strongly nonlinear pore structures of pulverized coals can be described by the fractal theory. The pore fractal dimensions of 10 pulverized coals, which are in the range of 2.572~2.722, were analyzed on a N2 adsorption porometer. The apparent viscosities of coal water slurries (CWS) were measured on a Haake rotary viscometer. The impacts of pore fractal dimension, inherent moisture, oxygen content and grindability index on CWS properties were discussed and the correlative empirical formulae were obtained. When the pore fractal dimensions of different coals increase from 2.61 to 2.643 and 2.698, which results in the increasing specific surface areas and pore volumes, the maximum CWS solid concentrations decrease from 70.8% to 69.2% and 62.4%, while the CWS viscosities increase from 879 to 1900 and 2006 mPa×s at the shear rate of 20 s-1. The increased pore fractal dimension, inherent moisture, oxygen content and the decreased grindability index are not beneficial to the CWS properties.