Abstract:This article is based on the diffusion theory of relative volume concentration H M. The Ismail equation is combined with the flow state discrimination criteria of E.J. Vasp and Wang Shaozhou slurries, and Liu Dezhong’s exponential calculation method is used to determine the flow state discrimination calculation of slurries. The volume concentration of quasi homogeneous slurries and heterogeneous slurries are obtained, and based on the relative volume concentration of slurries, the concept of coarse and fine particle boundary particle size is proposed. On this basis, the concept of heterogeneous slurry volume concentration increasing resistance is proposed, and the concepts of boundary particle size and increasing resistance are defined, Derive the formula for calculating the resistance of slurry pipelines using the drag coefficient method, which has been verified by six long-distance slurry pipeline projects in China. The calculation results are similar to the actual engineering situation.