WANG Yongbiao’s team at China Coal Xi’an Design Engineering Co. Ltd. has just handed the mining industry a practical playbook for turning a persistent headache—high-salinity mine water—into a reliable underground resource. Their pilot at Nalinhe No. 2 Mine in Inner Mongolia shows that reverse osmosis can deliver clean water deep below the surface, cutting both costs and haulage risks for large, deep mines.
“Before this project, high-hardness, high-salinity water was treated above ground or not treated at all,” Yongbiao explains. “Moving that water hundreds of meters up and down the shaft is expensive and risky. We proved you can do the heavy lifting underground, where the water is already warm and the footprint is minimal.”
The team’s three-month run produced more than 65 % permeate from feed water averaging 60 μS/cm conductivity, meeting the tight specs for hydraulic dust suppression, emulsion mixing and equipment cooling. By siting the RO skid in a dedicated roadway alcove—complete with vibration-damped frames and explosion-proof enclosures—they sidestepped the need for costly surface plants and long pipelines.
For energy operators wrestling with water scarcity and disposal limits, the numbers tell the story. Yongbiao cites a 30 % reduction in make-up water trucking and a 25 % cut in reagent use compared with surface treatment. “When you’re sinking a shaft 600 meters, every cubic meter you reuse is one less you have to haul,” he notes. “That translates to faster cycle times and lower capital tied up in storage dams.”
The paper, published in Gongye shui chuli (Industrial Water Treatment), offers a template that is already drawing interest from coal and metal mines in Shaanxi and Inner Mongolia. Yongbiao’s group is now modeling larger, multi-stage RO trains for mines with even higher TDS loads, hinting that the next leap could be zero-liquid-discharge configurations that eliminate brine disposal altogether.
What makes the work stand out is its refusal to chase the perfect solution in favor of the practical one. “We didn’t invent new membranes,” Yongbiao admits. “We simply asked how to make existing ones work reliably in a tunnel, under 0.8 MPa back-pressure and 35 °C ambient. That’s where the real savings hide.”