by Ish Mohan Garg, Senior Vice President, Calderys APAC region
Steel, the backbone of modern civilisation, is entering a decisive era as industries worldwide push toward cleaner production. While the sector remains one of the largest emitters of greenhouse gases, rising demand—especially across India and other emerging regions—makes decarbonisation both urgent and inevitable. Amid this transition, refractories, the high-temperature materials that protect and optimise steelmaking furnaces, are emerging as critical enablers. Their innovations in durability, efficiency, and sustainability are quietly reshaping the path to green steel
Steel is regarded as the backbone of modern civilization – the invisible structure that supports our bridges, buildings, rail systems, and renewable energy infrastructures. As crucial as it is, steel, like cement, is one of the most carbon-intensive industries in the world and is responsible for about 7–9% of global greenhouse gas emissions. If demand for steel increases, as it is expected to, particularly in developing regions such as India, ASEAN, and Africa, the prospect of decarbonising steelmaking becomes not only an environmental imperative but also an extraordinary technological opportunity.
In this transformation, refractories – the heat-resistant materials that line furnaces, ladles, and converters – are quietly taking center stage. Once viewed as background materials, refractories now shape the efficiency, durability, and sustainability of every tonne of steel produced.
The unsung enablers of clean steel
The process of steel production, from melting through to refining, relies heavily upon refractory materials that can withstand temperatures of over 1,600°C, resist corrosion and ensure thermally stable furnace conditions. The quality of these materials ultimately determines energy efficiency, heat loss and even the purity of the steel produced.
In conventional blast furnaces, where refractory wear represents an important source of total carbon intensity from energy losses, modern electric arc furnaces (EAF) with advanced refractories permit steel production with a better energy and emissions profile. Such linings can also improve the life of the furnace and lower both the maintenance downtime and waste material associated with maintenance – all impact factors to further reduce total carbon emissions associated with a steel plant.
Magnesia-carbon (MgO-C) bricks, for instance, are vital for withstanding slag corrosion in EAFs and ladles. Their transition toward low-carbon formulations – with modified graphite formulation, nano-additives, and composite powders – assists to minimise carbon output while maintaining thermal stability. Likewise, monolithic refractory solutions, including dry-vibratable hearths and cast-in-situ linings, support superior installation, consistent heat transfer, and decreased energy usage.
Innovation at the heart of operation
As India pushes for more sustainable industrial growth, innovation in refractory materials and design is accelerating. Manufacturers are increasingly turning to renewable energy sources in refractory production, with some manufacturing plants incorporating solar power as part of the energy mix. The adoption of renewable sources highlights how production can make substantial reductions in carbon intensity while increasing efficiency levels.
Sustainability initiatives also include responsible resource management. The leading refractory plants are being built as zero effluent discharge facilities so that wastewater can be treated and reused for landscape and servicing operations. This, along with water harvesting and groundwater recharge initiative, enhances long-term water security while maintaining industrial productivity.
Manufacturers are embracing bio-based binders and secondary raw materials to cut embodied carbon. The production of biobinders from renewable sources, such as lignin or vegetable oils, results in lower emissions compared to their petroleum-based equivalents. Meanwhile, the use of recycled refractory aggregates supports circularity and reduces dependency on virgin raw materials. Green cover initiatives are becoming a signature of sustainable refractory manufacture, with large parts of facilities being turned into verdant green areas to promote biodiversity and contribute to carbon offsetting.
Next-generation coatings and nano-structured refractories are also changing the game for thermal efficiency. Nanocoatings improve heat insulation in addition to providing self-healing capabilities – auto-mending cracks at high temperatures to continue protecting the asset. These new coatings extend the life of refractories and reduce fuel consumption of steel furnaces, improving sustaining performance.
Artificial intelligence (AI) and predictive analytics are further reshaping refractory management. The integration of sensors in furnace linings allows for real-time condition monitoring of wear patterns and thermal stresses. Based on sensor data, AI models can predict future maintenance, helping to minimise unplanned downtime and optimise energy efficiency. This leads to longer refractory life, enhanced reliability, and decreased costs.
Towards circular and low-carbon operations
The path to low-carbon steelmaking in India also entails rethinking the life cycle of refractory materials. Traditionally, spent refractories have been sent to landfills, but now they are being reprocessed and reintegrated into production. This involves working with recycling companies to recover minerals from spent linings, reducing waste and lowering environmental impact. Additionally, many modern facilities now extract and recycle refractory minerals back into products. In addition to improved dust and emission control systems – which can provide air that is multiple times cleaner than traditional standard – this circular system is significantly reducing environmental footprints.
These changes are in line with the wider goals of industrial sustainability in India. With greater emphasis on decarbonisation, local production, and circular economy practices, the steel industry in India is beginning to move towards cleaner production practices. As industries look to adopt greener technologies and/or resource-efficient processes, refractories are becoming, once again, a key enabler of improving furnace performance, reducing waste, and lowering carbon emissions throughout the steel value chain.
Laying the foundations for future resilience
Innovations in refractories are inextricably linked to the new low-carbon steel technologies emerging through hydrogen-based direct reduced iron (H-DRI), bioenergy hybridisation, and renewably powered Electric Arc Furnaces (EAF). Each route has specific lining requirements to manage new thermal profiles, new chemical reactions, and new energy.
The focus is now on longer life, lower-carbon, and more intelligent refractories, which encourage round-the-clock steel production while reducing energy use and emissions. The intersection of nanotechnology, digital monitoring, and sustainable material sourcing are paving the way for new productivity and responsibility standards.
Conclusion: The silent backbone of the green steel revolution
Decarbonising steel is not merely about finding substitutes for coal, such as hydrogen or carbon capture; it is about redesigning every part of the process, and refractories are at the core of this change. They represent the merger of material science and environmental sustainability, empowering furnaces to be more efficient, effective, and to last longer.
As India and the global steel sector move toward a net-zero future, the innovation hidden within refractory linings may determine how strong, sustainable, and green the next industrial revolution will be.
