螺旋分选是细粒煤高效绿色分选的核心技术之一，探明细粒煤螺旋分选全过程流体−颗粒空间分布特征有利于深入理解螺旋分选行为。以螺旋分选全过程为研究对象，研究了流场、颗粒在螺旋分选全过程的空间分布规律。通过建立颗粒螺旋分选动力学方程并基于螺旋分选流场的多流态特性，构建了复合流态下流体曳力计算模型；结合颗粒堆积实验采用响应面法对颗粒间接触参数进行标定，优化了CFD-DEM耦合模拟方案。结果表明：① 依据流场分布和颗粒运动行为，细粒煤螺旋分选全过程可分为初始阶段(0～1/3圈)、过渡阶段(1/3～2圈)和亚稳定阶段(2圈以后)。在初始阶段，不同密度、不同粒度颗粒在螺旋槽中的分布基本一致：沿螺旋槽倾斜方向分布并逐渐向槽外缘聚集；② 过渡阶段内高密度颗粒随着粒度的增大颗粒逐渐向内缘聚集，低密度颗粒逐渐聚集在槽外缘；③ 在亚稳定阶段，高密度颗粒随着粒度的增大越来越多的颗粒聚集在螺旋槽内缘，不同粒度的低密度颗粒均主要聚集在槽外缘。此外，粒度对高密度颗粒空间分布有显著影响，而对于低密度颗粒分选行为影响不大，颗粒粒度低于0.1 mm时，颗粒间按密度差异分选的趋势降低，高密度细颗粒难以依靠密度差沉降到槽底参与二次环流的径向输送，导致其主要聚集在螺旋槽外缘，与低密度颗粒混杂，不利于细粒煤的分选。

Spiral separation is one of the core technologies for the efficient green separation of fine coals, and the investigation of fluid-particle spatial distribution characteristics in the whole process of spiral separation of fine coals is beneficial to the in-depth understanding of spiral separation behavior. Taking the whole process of spiral separation as the research object, the spatial distribution law of flow field and particles in the whole process of spiral separation is studied. By establishing the particle spiral separation kinetic equations and based on the multi-flow characteristics of the spiral separation flow field, a computational model of fluid drag force in the composite flow state is constructed. The results show that: ① According to the flow field distribution and particle motion behavior, the whole process of fine coal spiral separation can be divided into initial stage (0−1/3 turns), transition stage (1/3−2 turns) and sub-stable stage (after 2 turns). In the initial stage, the distribution of different density and particle size in the spiral trough is basically the same: distribution along the spiral trough inclination direction and gradually gathering to the outer edge of the spiral trough. ② In the transition stage, high-density particles gradually gather to the inner edge as the particle size increases, and low-density particles gradually gather at the outer edge of the trough. ③ In the sub-stable stage, more high-density particles gather at the inner edge of the spiral trough as the particle size increases, and low-density particles with different particle sizes are mainly gathered at the outer edge of the spiral trough. In addition, particle size has a significant effect on the spatial distribution of high-density particles but has little effect on the separation behavior of low-density particles. When the particle size is less than 0.1 mm, the tendency of separation between particles according to density difference is decreased. Therefore, it is difficult for high-density fine particles to sink to the bottom of the spiral trough to participate in the radial transport of secondary circulation by density difference, causing them to mainly gather at the outer edge of the spiral trough and mix with low-density particles, which is unfavorable to the separation of fine coals.