With the tightening of national environmental policies, deep treatment and zero discharge of coal mine water have becoming inevitable requirements for the sustainable development of the industry. The difficult problem of treating high salinity and high hardness mine water was focused on. Based on the analysis of water quality characteristics (TDS 3 967 mg/L, total hardness 1 131 mg/L), a technical comparison and system design of deep treatment processes were carried out. The research has determined that the core process is "dual alkali softening high-density precipitation ultrafiltration multi-stage reverse osmosis", in which the caustic soda pure alkali method is used to achieve efficient hardness removal, and multi-stage RO is combined to achieve segmented desalination and concentration. The operation simulation showed that the overall recovery rate of the system can reach 88%, the TDS of the produced water is ≤ 100 mg/L, and the hardness is ≤ 10 mg/L, which meets the industrial reuse standards. The concentrated water can be reused as a resource, achieving efficient desalination and near zero discharge, providing reliable technical reference for high salt mine water treatment.
