Research progress and prospects of deep underground storage technology for high-salinity mine water

Objective High-salinity mine water distribute widely in mining areas of China. Discharging and utilizing pose significant challenges to both the ecological environment and resource utilization. In recent years, deep underground storage technology has gained widespread attention as an environmentally friendly and resource-efficient approach for mine water management.

Progress  Focusing on the key characteristics of high-salinity mine water, this study systematically reviewed the key scientific issues and technical bottlenecks associated with deep underground storage. It examined the principles, technical classifications, and engineering applications of the technology, and comprehensively evaluated its applicability boundaries. Core aspects included geological condition assessment, injection well design, water quality pretreatment, process monitoring, and storage stability evaluation. A site selection method for suitable storage formations was proposed based on four characteristics: regional tectonics, basic geology, physical properties of the reservoir and caprock, and hydrogeological conditions. The structural design principles for injection wells were defined by integrating three factors: safety and environmental protection, injection efficiency, and economic feasibility. The advantages and disadvantages of mine water pretreatment technologies were clarified, along with the required water quality control standards for injection. On this basis, a dynamic monitoring system for the entire reinjection process was established, and an evaluation method for the storage stability of mine water based on multi-physics coupling was developed. Furthermore, limitations of existing technologies were summarized, including issues such as scaling, corrosion, geological disturbances, and potential environmental risks.

Outlook  Finally, future development should focus on efficient and low-consumption water treatment technologies, scaling and corrosion prevention systems, geological environmental impact assessments, and the improvement of relevant policies and regulations. This will provide a scientific basis for establishing a new paradigm of low-carbon mine water treatment. Deep underground storage of high-mineralization mine water not only addressed the issue of mine water discharge but also facilitated water resource recycling, offering significant environmental and economic benefits. With the continuous breakthrough of efficient and low-consumption processing technology and new functional materials, this technology will develop towards standardization, intelligence and greening.