Environmental Risks of Coal Gangue Filling Revealed by New Research

Strategic Insights -

New research from the China University of Mining and Technology has shed light on the environmental risks associated with coal gangue (CG) filling. The study, published in Environmental Research, evaluated the environmental risks of CG filling through leaching experiments and numerical simulation methods. The results showed that under acidic conditions, the leaching concentration of heavy metals in CG is relatively high, exceeding Class I discharge standards.

Key Takeaways:

  • The leaching concentration of heavy metals in CG is relatively high, with copper concentration reaching 0.80 mg/L under acidic conditions, exceeding Class I discharge standards.
  • Under neutral conditions, the leachate indicators meet national standards, but the reclaimed soil has a relatively low fertility level (soil quality index 0.416) and cadmium becomes the primary ecological risk factor.
  • A layered compaction process can effectively control the migration of leachate, with maximum migration depth of pollutants being 17 meters.
  • Numerical simulations indicate that concentrations stabilize after 2500 days, and the high mineralization of groundwater is primarily influenced by the geological background values.
  • The study recommends conducting long-term field monitoring to comprehensively assess the environmental impact.
  • Engineered CG filling reclamation presents controllable environmental risks and resource utilization potential, but there are limitations, such as a short monitoring period and uncertainties in the model predictions.
  • The study highlights the importance of careful management and regulation of CG filling activities to prevent environmental risks.

Statistics:

  • The leaching concentration of copper in CG is 0.80 mg/L under acidic conditions.
  • The maximum migration depth of pollutants is 17 meters.
  • Concentrations stabilize after 2500 days.
  • The soil quality index of the reclaimed soil is 0.416.
  • The diffusion range of the fluoride contamination plume is less than 204 meters.

Sources:

Environmental Research, 2025:122303

  • China University of Mining and Technology, School of Geoscience and Surveying Engineering, Beijing 100083, People's Republic of China
  • Xihui Liu, Zhenqi Hu, and Jingwei Gao
  • Academic Press Inc Elsevier Science, 525 B St, Ste 1900, San Diego, CA 92101-4495, USA
  • Environmental Research - www.journals.elsevier.com/environmental-research/

NewsRx LLC, 2025 - reporting by NewsRx staff