Abstract: Particulate matter in mine water is composed of clay, pulverized coal and a small amount of non-clay minerals, which has fine particle size distribution and obvious coal-rock surface characteristics, and shows high dispersion stability in mine water, which has become the focus of mine water treatment. The typical SO₄−Na·Ca type mine water in Xishan mining area of Shanxi Province is selected, and the particles which are difficult to settle are separated by sedimentation experiment, and their physical and component characteristics are analyzed. Single-factor variable experiments were designed to analyze the differences in dispersion stability of difficult settling particles under the changes of typical cations （Ca²⁺, Mg²⁺, Na⁺） and anions （C1⁻, \mathrmSO_4^2- ） of the water type. Based on the Zeta potential distribution on the surface of particles and the DLVO theoretical calculation, the mechanism of the influence of water chemical properties on the interaction behavior of particles was investigated from the microscopic level. The results show that with the increase of cationic Ca²⁺, Mg²⁺ and Na⁺ concentrations, the dispersion stability of refractory particles in mine water gradually decreases, and the absolute Zeta potential on the surface of particles and the repulsion potential energy between particles gradually decrease, and the reduction degree is Ca²⁺>Mg²⁺>Na⁺. When Ca²⁺ is at 20 mmol/L, the energy barrier of intergranular repulsion potential energy decreases from 4.77×10⁻¹⁸ J to 1.05×10⁻¹⁸ J, and the absolute value of Zeta potential decreases from 53.7 mV to 6.2 mV. Under the condition of anionic variable, the absolute Zeta potential of 20 mmol/L MgSO₄ particles increased by 7 mV compared with 20 mmol/L MgCl₂, and the potential energy barrier of interparticle repulsion increased from 2.06×10⁻¹⁸ J to 3.66×10⁻¹⁸ J. It is shown that \mathrmSO_4^2- compared with C1⁻ increases the stability and interparticle repulsion potential energy of the dispersion system. This discovery is helpful to optimize coagulation treatment according to the type of water chemistry, and has important significance for the recycling of mine water.