Coal Mine Wastewater as a Secondary Resource: Advances in Treatment and Value Recovery Technologies

Coal mine wastewater, which has historically been considered an environmental problem, is becoming more widely recognized as a secondary resource with substantial value recovery potential. Nevertheless, recent progress demonstrates that this wastewater could be converted into highly useful, industrially available pigments (like iron oxides) by methods including chemical precipitation, biosorption, and advanced oxidation. Additionally, the use of membrane filtration, constructed wetlands, and electrochemical‐based solutions presents a promising potential for producing safe‐for‐reuse water. These treatment solutions are thoroughly examined to analyze their efficiency, economic viability, and environmental performance, which helps assess the feasibility of deploying them on an industrial scale for integration into the existing wastewater treatment network. Despite tremendous advancements, there are still difficulties in managing secondary waste streams, processing complicated matrices, and transferring lab results to industrial settings, which hinder the effective implementation of these treatment solutions in real‐world applications. This review highlights important knowledge gaps and future research initiatives required to move from remediation‐focused management to sustainable resource recovery and long‐term environmental stewardship by examining coal mine wastewater from the perspective of the circular economy.