Coal water slurry gasification is a main source of hydrogen in the developing hydrogen economy. Moreover, biomass and waste can be added, making gasification process greener. To expand the application of coal water slurry and gasification process, it is necessary to understand the micro-structure in this large particle suspension system. In this paper, the micro-structure in coal water slurry was studied by extended DLVO (eDLVO) theory and fractal dimension, which is used to explain the mechanism of stability in large particle suspension systems. The interaction between two coal particles was characterized from the interparticle potential and energy barrier based on the eDLVO theory. The rheology and stability between different types of coals are measured and explained by the aggregating structure and fractal dimension in coal water slurry. The results indicated that there would be an aggregating structure in high rank coals, due to the interparticle potential caused by the surface properties, but probably not in low rank coals. This aggregating structure can be described and characterized by fractal dimension. The aggregation of particles is the source of the stability for high rank coals, as the close-packed 3D network structure in large particle suspension can support coal particles from settling down. The results have demonstrated that the combination of the eDLVO theory and rheological measurement is an effective way to investigate the stability of large particle suspension systems.

在发展的氢经济中，水煤浆气化是氢的主要来源。此外，可以添加生物质和废物，使气化过程更环保。为了扩大水煤浆和气化工艺的应用范围，有必要了解这种大颗粒悬浮系统的微观结构。本文采用扩展的DLVO（eDLVO）理论和分形维数研究了水煤浆的微观结构，用以解释大颗粒悬浮体系的稳定性机理。基于eDLVO理论，通过颗粒间的势能和能垒来表征两个煤颗粒之间的相互作用。通过水煤浆的聚集结构和分形维数来测量和解释不同类型煤之间的流变学和稳定性。结果表明，由于表面性质引起的颗粒间电势，在高等级煤中将存在聚集结构，而在低等级煤中则可能不存在聚集结构。这种聚集结构可以用分形维数来描述和表征。颗粒的聚集是高阶煤稳定性的来源，因为大颗粒悬浮液中密堆积的3D网络结构可以支持煤颗粒沉降。结果表明，eDLVO理论与流变学测量相结合是研究大颗粒悬浮液系统稳定性的有效方法。这种聚集结构可以用分形维数来描述和表征。颗粒的聚集是高阶煤稳定性的来源，因为大颗粒悬浮液中密堆积的3D网络结构可以支持煤颗粒沉降。结果表明，eDLVO理论与流变学测量相结合是研究大颗粒悬浮液系统稳定性的有效方法。这种聚集结构可以用分形维数来描述和表征。颗粒的聚集是高阶煤稳定性的来源，因为大颗粒悬浮液中密堆积的3D网络结构可以支持煤颗粒沉降。结果表明，eDLVO理论与流变学测量相结合是研究大颗粒悬浮液系统稳定性的有效方法。