A comprehensive understanding of the characteristics and formation mechanisms of groundwater in mining areas is essential for the effective prevention of coal mine water and the rational management of groundwater resources. The objective of this study was to examine the hydrogeochemical characteristics and evolution of Ordovician groundwater in the Zhuozishan coal mine, located in the northwest region of China. A total of 34 groundwater samples were collected for hydrogeochemical analyses and the investigation of their evolution processes, with the aid of a piper trilinear diagram, a Gibbs diagram, and an ion ratio diagram. The results indicate that the concentration of sodium (Na⁺), potassium (K⁺), bicarbonate (${\mathrm{HCO}}_3^{-}$), chloride (Cl⁻), sulphate (${\mathrm{SO}}_4^{2-}$), total dissolved solids (TDS), and pH increases from the recharge area to the discharge area, whereas the concentration of calcium (Ca²⁺) and magnesium (Mg²⁺) decreases. The hydrogeochemical characteristics of the runoff from Zhuozishan to Gongdeer coalfield and further southward display a notable north–south directional change. The groundwater process is primarily controlled by rock weathering action and cation exchange, with Na⁺ and K⁺ deriving primarily from cation exchange and only to a minor extent from halite dissolution. In conclusion, the northern part of the coalfield is characterised by a geological structure that creates a retention area with groundwater, resulting in an unordered runoff process with a complex formation mechanism. The middle region is devoid of geological constraints that would alter the flow direction, thus simplifying the process of groundwater formation. In contrast, the southern area experiences an increase in strata depth and fault blocking, which creates a retention zone, thereby rendering the groundwater formation process more complex. This research contributes to the effective management of groundwater resources in this coalfield and other mining sites.

Investigating ecological irrigation risks associated with mine water utilization is of great significance for alleviating water resource shortages in arid mining regions of western China, thereby supporting efficient coal extraction and coordinated ecological development. In this study, a representative mining area in Xinjiang was investigated to reveal the evolution patterns of mine water quality under arid geo-environmental conditions in western China and to systematically assess environmental risks induced by ecological irrigation. Surface water, groundwater, and mine water samples were collected to study ion ratio coefficients, hydrochemical characteristics, and evolution processes. Based on this, a multi-index analysis was employed to evaluate ecological irrigation risks and establish corresponding risk control measures. The results show that the total dissolved solids (TDS) of mine water in the study area are all greater than 1000 mg/L. The evolution of mine water quality is mainly controlled by water–rock interaction and is affected by evaporation and concentration. The main ions Na⁺, Cl⁻, Ca²⁺, and SO₄²⁻ originate from the dissolution of halite, gypsum, and anorthite. If the mine water is directly used for irrigation without treatment, the soluble sodium content, sodium adsorption ratio, salinity hazard, and magnesium adsorption ratio will exceed the limits, leading to the accumulation of Na⁺ in the soil, affecting plant photosynthesis, and posing potential threats to the groundwater environment. Given the evolution process of mine water quality and the potential risks of direct use for irrigation, measures can be taken across three aspects: nanofiltration combined with reverse osmosis desalination, adoption of drip irrigation and intermittent irrigation technologies, and selection of drought-tolerant vegetation. These measures can reduce the salt content of mine water, decrease the salt accumulation in the soil layer, and lower the risk of groundwater pollution, thus reducing the environmental risks of ecological irrigation with mine water. The research will provide an important theoretical basis for the scientific utilization and management of mine water resources in arid areas by revealing the evolution law of mine water quality in arid areas and clarifying its ecological irrigation environmental risks.