煤泥滤饼结构对脱水效果有重要影响，采用自制加压脱水装置及CT扫描等方法研究了压滤脱水过程中滤饼结构特性及其演化规律。将压滤过程修正为4个阶段，其中滤饼脱水阶段主要脱去滤饼内部水分，此阶段滤饼孔隙结构越发达则压滤脱水效果越好；滤饼压缩阶段主要对滤饼进行最后压缩，此阶段滤饼可压缩性越高，滤饼最终的孔隙率和含水量就越低。并采用聚合硫酸铁(PFS)和α−半水石膏(α-HH)对煤泥进行助滤实验。从煤泥颗粒絮团结构、滤饼物相组成、滤饼三维结构等多方面分析了助滤机理。结果表明：PFS和α-HH联合使用显著提升了煤泥的过滤效果，通过中心组合设计(CCD)，确定了2者最佳药剂量为1711.44 g/t和48.33 mg/g。在最佳条件下，滤饼含水量降低至16.97%，过滤速度提高至145.89 mL/(s·m²)。α-HH的加入使滤液Zeta电位的绝对值降低到1.45 mV，从而降低了煤泥颗粒之间的静电排斥力，增强了PFS的絮凝效果，使絮状物的弦长增加到71～171 μm。同时在PFS体系中，α-HH的水化反应被加速，形成大量二水石膏晶体，在煤泥絮体中形成交织的骨架，发挥了骨架构建体的作用，使煤泥压滤脱水指数(I_CD)提升至176.30，增强了滤饼强度，使压滤过程中煤泥滤饼孔隙率从12.14%提高到14.39%，提高了煤泥滤饼的孔隙配位数及连通性从而提高了过滤效果。

The structure of coal sludge filter cake has an important influence on the dewatering effect. In this study, the characteristics of the filter cake structure and its evolution law in the process of filter press dewatering were investigated by using the homemade pressurized dewatering device and CT scanning methods. The filter press process was modified into four stages. Among them, the cake dewatering stage mainly removes the internal water of the cake, and the more developed the pore structure of the cake in this stage, the better the dewatering effect of the filter press; the cake compression stage mainly compresses the cake at last, and the higher the compression of the cake in this stage, the lower the porosity and water content of the cake will be in the end. The polymerised ferric sulphate (PFS) and α-hemihydrate gypsum (α-HH) were used to carry out filtration aid experiments on coal slurry. The filtration-assisting mechanism was analyzed from various aspects, such as the flocculation structure of coal slurry particles, the composition of the physical phase of the filter cake, and the three-dimensional structure of the filter cake. The results showed that the combination of PFS and α-HH significantly enhanced the filtration effect of coal slurry, and the optimal dosage of the two was determined to be 1711.44 g/t and 48.33 mg/g by central combinatorial design (CCD). Under the optimal conditions, the water content of the filtrate cake was reduced to 16.97% and the filtration rate was increased to 145.89 mL/(s·m²). The addition of α-HH made the absolute value of filtrate zeta potential to 1.45 mV, which reduced the electrostatic repulsive force between coal slurry particles, enhanced the flocculation effect of PFS, and increased the chord length of flocs to 71-171 μm. Meanwhile, in the PFS system, the hydration reaction of α-HH was accelerated, and a large number of gypsum dihydrate crystals were formed, which formed the intertwined skeleton in the flocs of coal slurry, and played the role of the skeleton constructor. These gypsum dihydrate crystals increase the index of compression dehydration (I_CD) of coal tailing filter press to 176.30. The pore size of coal slurry filter cake was increased from 12.14% to 14.39% during the filtration process, which improved the pore coordination number and connectivity of the coal slurry filter cake and thus improved the filtration effect.