Ningdong Mine Water & Coal Chemical Wastewater Treatment and Reuse Project

Owner: CHN Energy Ningxia Coal Industry Co., Ltd., built and operated by its Coal Chemical Utilities Branch. Location: Ningdong Energy and Chemical Base, Ningxia. The “No.1 environmental project” of Ningxia Coal is China's first 3,000 m³/h combined mine-water and coal-chemical wastewater plant, occupying 201,000 m² with a total investment of RMB 1.69 billion. Stage one covers pre-treatment and membrane desalination of mine tail water and coal-chemical wastewater; stage two treats the resulting brine by two-stage ozone catalytic oxidation, nanofiltration salt separation and evaporation crystallisation, achieving zero liquid discharge for the park. It produces 24.09 million m³ of reuse water annually plus 39,900 t of first-grade sodium chloride, 43,200 t of anhydrous sodium sulphate and 14,400 t of mixed salt, all utilised. By 2026 daily throughput had risen from 35,400 m³ to 55,000 m³ at over 90% load, with effluent COD ≤15 mg/L and ammonia nitrogen ≤0.5 mg/L. Sources: SASAC/Ningxia SASAC (24 Apr 2019); Ningxia Water Resources Department (5 Aug 2026); People's Daily Ningxia (27 Jul 2026). Image: Mine water and coal-chemical wastewater treatment facility at Ningdong (photo: Ningxia Water Resources Department)