In the heart of China’s coal industry, a pressing environmental challenge has emerged, one that threatens to cast a long shadow over the energy sector’s future. Acid coal mine drainage, with its corrosive nature and stubborn persistence, has become a formidable foe, and researchers are rallying to find effective solutions. At the forefront of this battle is Honghu Tang, a scientist from the School of Minerals Processing and Bioengineering at Central South University in Changsha, who has recently published a comprehensive analysis of the issue in the Journal of Engineering Science, known in Chinese as ‘工程科学学报’.
Tang’s research paints a stark picture. Acid coal mine drainage, he explains, is a complex environmental problem characterized by its large output, wide pollution range, and long duration. “The drainage contains a significant amount of soluble iron, manganese ions, and suspended solids,” Tang notes, “and its low pH and unstable effluent quality and quantity make it a persistent challenge for the coal industry.”
The problem stems from two main sources: underground goaf water and coal gangue accumulation. In closed small and medium coal mine factories, water accumulates in the underground goaf, leading to the oxidation of coal and the production of acid drainage. Meanwhile, large coal mines, which are still operational, face leaching pollution due to the large accumulation of coal gangue.
The commercial impacts of this issue are substantial. The current treatment methods, which primarily involve terminal treatments like chemical neutralization and microbial processes, are time-consuming, costly, and often inadequate. “The continuous pollution of water sources makes it difficult to control the problem with terminal treatment alone,” Tang warns.
However, Tang’s research offers a glimmer of hope. He advocates for a shift towards source control and path interception technologies. “Source control technologies, such as sterilization, coverage, passivation, and carrier-microencapsulation, have been developed,” he explains, “and path control technologies, like the roadway closed filling technology, are being used, but they are not yet mature.”
The potential for future developments in this field is significant. Tang’s research suggests that a comprehensive approach, combining source treatment, path blocking, and end treatment, could be the key to mitigating acid coal mine drainage pollution. Moreover, he proposes innovative concepts like “comprehensive utilization of resources” to recover valuable substances and “treating waste with waste” acid–base neutralization, which could not only address the environmental challenge but also turn it into an opportunity for resource recovery.
As the energy sector grapples with this environmental challenge, Tang’s research serves as a beacon of hope. His work underscores the need for a multi-faceted approach to the problem, one that combines innovative technologies and sustainable practices. It’s a call to action for the industry, a reminder that the path to a sustainable future lies in our ability to turn environmental challenges into opportunities for innovation and growth.