Assessment and characterization of waste material used as backfilling in an abandoned mine

ABSTRACT

Overburden is the earth material removed during opencast mining, which is typically not contaminated with toxic materials. After mining operations, overburdens are dumped on exhausted mining sites. However, some opencast mines are not properly backfilled, and this causes harmful environmental effects, such as leaching of acid mine drainage. The flyash produced from thermal power plants is also a major waste that must be disposed of environmentally friendly. This study focuses on filling the voids of an abandoned mine with a mixture of 70% overburden + 30% flyash. A considerable improvement in acid mine drainage characteristics was found after either adding overburden or an overburden and flyash mixture. Sustainable management of coal mines should include the careful restoration of exhausted mines, which can be made possible by repurposing relevant industrial waste.

KEYWORDS:

• coal mining
• opencast mines
• overburden materials
• flyash
• abandoned mine

Acknowledgment

The authors would like to express the highest gratitude to the Indian Institute of Technology (BHU) and other organizations which are around the Singrauli coalfield that helped in this research work; the Ministry of Human Resource Development (Govt. of India).

Contributions

Conception and design of the study were planned by SS, AJ, and AKY; Data collection was performed by SS and AKY and analysis was performed by SS, AJ and AKY. Data interpretation was carried out by SS, AJ and AKY. The first draft was written by SS and AKY. Review and edited by SS, AJ, CE, VPS and AKY. All the authors proofread and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).