Unconventional Energy Resources as Sources of Critical Minerals: Coal, Oil, Gas, and Produced Waters

Submission Deadline: 30 November 2026 View: 52 Submit to Special Issue

Guest Editors

Assoc. Prof. Manoj Khandelwal

Email: m.khandelwal@federation.edu.au

Affiliation: Institute of Innovation, Science and Sustainability, Federation University Australia, Ballarat, Australia

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Research Interests: mining sustainability, mining geomechanics, rock engineering, AI/ML applications in mining

Assoc. Prof. Moshood Onifade

Email: m.onifade@federation.edu.au

Affiliation: Institute of Innovation, Science and Sustainability, Federation University Australia, Ballarat,  Australia

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Research Interests: sustainable mining, clean energy minerals, spontaneous combustion and coal applications, mine safety and environment, soft computing applications in mining

Assoc. Prof. Samson Oluwaseyi Bada

Email: samson.bada@wits.ac.za

Affiliation: School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa

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Research Interests: coal, flyash, combustion, clean energy minerals, bamboo

Prof. Bekir Genc

Email: bekir.genc@wits.ac.za

Affiliation: School of Mining Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa

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Research Interests: coal-combustion, spontaneous combustion, energy, coal-research

Summary

The growing global demand for critical minerals, including rare earth elements, lithium, vanadium, cobalt, and germanium, is driving research into alternative and sustainable sources beyond traditional mineral deposits. Coal, oil, and natural gas resources, together with their associated by-products, have emerged as promising unconventional sources. In particular, coal ash, coal gangue, drilling wastes, and oil & gas produced waters offer significant potential for mineral recovery while enabling waste valorisation and supporting environmental sustainability.

This Special Issue aims to provide a platform for cutting-edge research on the recovery, characterisation, and sustainable utilisation of critical minerals from coal, oil, and natural gas systems. Contributions are encouraged that explore innovative extraction and separation technologies, geochemical and mineralogical characterisation, process optimisation, and integrated techno-economic and environmental assessments. Studies addressing the circular economy, energy–mineral supply chains, and practical pilot-scale or industrial applications are especially welcome.

Topics of interest include, but are not limited to:
· Occurrence and distribution of critical minerals in coal, oil, and gas systems
· Recovery of minerals from coal ash, mine waste, and produced water
· Advanced physical, chemical, and biohydrometallurgical methods
· Techno-economic, environmental, and life-cycle assessments

This Special Issue seeks to advance interdisciplinary approaches linking energy production, critical mineral supply, and sustainable development.

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