Recovery of Critical Minerals from Coal Mine Waste and Coal Ash

 Background and Context

• India is exploring coal waste and ash as alternative sources for Critical Minerals, especially Rare Earth Elements (REE).

• Fly ash, bottom ash, and overburden from coal mining are found to contain significant concentrations of REE and Yttrium.

• This initiative supports India’s broader self-reliance and clean energy goals, including the National Critical Minerals Mission (NCMM).

Key Findings from Recent Studies

a) Singareni Thermal Power Plant (STPP)

• Total REE in fly ash and overburden clay: ~400 ppm

b) NLC India Ltd., Neyveli (Tamil Nadu)

• Fly ash REE concentration: 2100 mg/kg

• Yttrium content: 300 mg/kg

• Contains both Light REEs (LREE) and Heavy REEs (HREE)

c) Coal India Ltd. R&D Findings

1. North Eastern Region (NER) Coalfields:

   • Low total REE, but high HREE content

2. Gondwana Sediments (Singrauli coalfield):

   • REE enrichment:

     • Coal samples: ~250 ppm

     • Non-coal samples: ~400 ppm

   • Extraction viability depends on tech advancement and economic feasibility

3. North Eastern Coalfields:

   • Developing indigenous technology for extraction:

     • Enrichment via physical separation

     • Extraction via Ion-Exchange Resin and Acid Mine Drainage treatment

National Critical Mineral Mission (NCMM)

• Launched: 29 January 2025

• Duration: 2024–25 to 2030–31

• Objective: Secure supply chain of Critical Minerals

• Allocation: ₹100 crore for pilot projects (e.g., fly ash, overburden, red mud)

• Centre of Excellence (CoE): Guidelines approved on 6 April 2025

Institutional Collaborations

• SCCL signed MoUs with:

  • IMMT, Bhubaneswar

  • NFTDC, Hyderabad

  • IIT Hyderabad

Significance for UPSC

• Supports energy security, Atmanirbhar Bharat, and critical mineral diplomacy

• Aligns with India’s Clean Energy Transition and Rare Earth Security Strategy

• Offers an eco-friendly solution by utilizing waste for wealth from coal mining