Dr. Asmita Maitra pursued her master and doctorate degree from the Indian Institute of Technology Kharagpur (IIT KGP) India. She has pioneered research into how India’s vast industrial and mining wastes can be harnessed for climate action. Her project is a unique testament of successful Indo–UK collaboration that combines advanced laboratory science in Southampton with field samples and industrial partnerships in India.
The India Centre for Inclusive Growth and Sustainable Development
Reducing Greenhouse Gases through Carbon Storage
Project: Greenhouse Gas Reduction Utilising Enhanced Weathering of Indian Industrial and Mine Wastes
Researcher: Dr. Asmita Maitra, Royal Society Newton International Fellow, School of Ocean and Earth Science, Faculty of Environment and Life Sciences
Background
Climate change is one of the greatest challenges of our time, driven largely by the relentless increase of atmospheric carbon dioxide (CO₂). While global efforts focus on reducing emissions, it is becoming increasingly clear that complementary “negative emission technologies” will be essential to achieve net zero. One promising approach is enhanced weathering—a method that accelerates natural rock weathering to capture and permanently store CO₂.
The project’s vision is simple yet impactful: turning industrial waste into a climate solution. Each year, India produces enormous quantities of mining tailings, overburden rocks, and industrial by-products such as steel slag and coal fly ash. These materials, often considered environmental liabilities, contain magnesium- and calcium-rich minerals capable of reacting with CO₂ to form stable bicarbonates. By accelerating this process under controlled conditions, they can act as long-term carbon sinks.
Objectives
Dr. Maitra’s research aimed to:
- Map and characterize the chemistry, mineralogy, and grain properties of major industrial and mine wastes in India.
- Evaluate their carbon dioxide removal (CDR) potential through laboratory simulations of weathering processes.
- Develop a methodology for a national inventory of waste streams that could support India’s climate goals and “green mining” policies.
India offers exceptional promise for enhanced weathering: its hot climate accelerates reactions, land availability eases deployment, and the scale of waste generation creates vast feedstock reserves. She collaborates with industry partners including Tata Steel (iron and chromite), Steel Authority of India Limited (SAIL), Odisha Mining Corporation (chromite), National Thermal Power Corporation alongside institutions such as Bhabha Atomic Research Centre (BARC), Indian Space Research Organisation (ISRO) and Indian Institute of Technology Kharagpur (IIT KGP).
She carried out extensive fieldwork across India, collecting representative samples from iron, copper, and chromite mines, as well as from steel plants and coal-fired power stations. These samples were then rigorously tested in Southampton laboratories using advanced petrographic, geochemical, and reaction experiments.
Key findings
- Certain mine wastes perform exceptionally well as carbon capture agents, showing higher CO₂ uptake capacity than conventional basalt—the benchmark material used globally for mineral carbonation.
- Industrial by-products such as steel slag and coal fly ash are also highly reactive, providing cost-effective pathways to integrate carbon capture within existing industries.
- Rock chemistry, mineralogy, and grain size play decisive roles in determining performance, highlighting the importance of careful site-specific selection and processing strategies.
- India’s chromite and ultramafic rock waste streams emerged as particularly promising candidates, offering scalable opportunities to align mining with climate solutions.
Crucially, this work demonstrates that enhanced weathering can be integrated into current industrial and mining operations—transforming unavoidable waste into a valuable resource for carbon management.
Impact
By providing a science-based framework to identify and utilize waste materials for carbon sequestration, Dr. Maitra’s project directly supports India’s ambitions for a circular economy and green mining policies. The approach creates a “win–win”: capturing CO₂ while reducing the burden of waste disposal.
On a broader scale, the project:
- Advances Indo–UK collaboration by combining Indian field resources with UK laboratory expertise. Partnerships with Tata Steel, Coal India Ltd., Odisha Mining Corporation, and cement producers ensure industry relevance and potential for real-world application.
- Builds capacity for future deployment in India by developing new methods and training early-career researchers in advanced geochemical experimentation.
- Positions India as a potential global leader in enhanced weathering, with strategies adaptable across both developing and developed economies.
Perhaps most importantly, this work reframes waste as a climate ally. Instead of being seen as a liability, mining and industrial by-products can become part of the solution—locking away millions of tonnes of CO₂ annually if deployed at scale.
Future work
The outcomes of this Newton Fellowship project open the door to scalable carbon removal strategies tailored to India’s geology and industry. The research provides policymakers and industry leaders with evidence-based insights to integrate enhanced weathering into national climate action. It also strengthens Indo–UK scientific collaboration in tackling one of the greatest environmental crises of our era.
As the current project illustrates, climate action often lies not in inventing something entirely new, but in rethinking what we already have. By turning India’s mine and industrial wastes into tools for carbon capture, this research exemplifies how science can inspire innovative, affordable, and globally impactful climate solutions.