Almost indispensable in advanced technologies, strategic resources of these REEs are now shaping international relations, determining a nation’s technological leadership, military capability and energy transitions.
Waste material coal fly ash is also a potential resource of valuable rare earth elements (REEs) which are retained and concentrated upon combustion. The government today told the Parliament that when coal-derived fly ash and bottom ash samples collected from Singareni Thermal Power Plant (STPP) and overburden clay samples were analysed for trace elements, they showed total REEs in fly ash and clays of about 400 ppm.
“Further, overburden, lignite and fly ash samples, collected from mines and thermal power plants of NLC India Limited at Neyveli, were also analysed for REEs and trace elements. It was found that fly ash from thermal power plant contains a concentration of REE (2100 mg/kg) comprising of both lighter and heavier REE with Yttrium content of 300 mg/kg,” Union Minister of Coal and Mines G Kishan Reddy told the Rajya Sabha in a written reply.
What are REEs?
REEs include rare elements like Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium and Scandium and Yttrium.
Besides their importance in various technological applications, REEs present in coal fly ash have an added advantage of potential for recovery from waste material. Fly ash, a byproduct of coal combustion, contains REEs that can be extracted and utilised, potentially mitigating supply risks associated with traditional mining, say experts
REEs and their geopolitical importance
Almost indispensable in advanced technologies, strategic resources of these REEs are now shaping international relations, determining a nation’s technological leadership, military capability and energy transitions.
In April China imposed export restrictions on seven rare earth elements like Samarium, Gadolinium, Terbium, Dysprosium, Lutetium, Scandium and Yttrium as retaliation against US tariffs imposed by President Donald Trump. It was not a total ban but restrictions tightened export licences, enabling China to limit global shipments. Companies needed special export licenses to export them.
China’s grip on over 90 % of these resources compelled nations to trade on its terms
Why are they indispensable?
REEs are vital for technologies like EV motors, smartphones, missiles and many more.
The Union Cabinet in January approved the launch of the National Critical Mineral Mission (NCMM) to secure critical mineral supply in the country.
The mission aims to reinforce India’s critical mineral value chain across all stages—from exploration and mining to beneficiation, processing, and recycling of end-of-life products—and ensure self-sufficiency in fulfilling the industrial demands for critical minerals. The NCCM also focused on recovery of critical minerals from sources such as overburden, tailings, fly ash, and red mud.
Coal India Limited has undertaken R&D projects related to rare earth elements found in coal mine waste.
What next
Results from assessment of REE and other economic resources from the North Eastern Region (NER) Coalfield, indicate that total REE is low, but heavy REE contents are relatively high, according to Reddy.
Results from appraisal of Gondwana sediments—coal, clay, shale, sandstone—f or Trace Elements & REE concentration in the Singrauli coalfield, indicate that REE are “promising” in nature (with an enrichment of ≈250 ppm on a whole coal basis in coal samples and ~400 ppm in non-coal samples). However, the economical extraction of the REE is subject to technical advancement and economy of scale.
The Singareni Collieries Company Limited (SCCL) has signed MoUs with Institute of Minerals and Materials Technology (IMMT), Bhubaneswar; Non-Ferrous Materials Technology Development Centre (NFTDC), Hyderabad; and IIT, Hyderabad for research in this field.
