As the global drive for greener steelmaking gathers momentum, RHI Magnesita is proud to support this transformation by partnering with Stahlwerk Thüringen (SWT) in Germany. In alignment with SWT’s green steel strategy—which includes using renewable energy sources and continual efficiency improvements—recent industrial trials have demonstrated that high-alumina circular metallurgical additives in combination with a slag engineering solution can significantly enhance the desulphurisation process in steel production. Detailed in the latest paper published in The Bulletin, these trials showcase operational improvements and notable environmental benefits, marking a key step forward in sustainable steel production.
Enhanced Slag Engineering with Circular Additives
Steelmaking currently accounts for over 7% of global greenhouse gas emissions, underscoring the urgent need to decarbonise the industry. Traditionally, steel ladle desulphurisation has relied on conventional fluxing agents such as calcium aluminate additives and fluorspar (CaF₂) to achieve the desired reactive slag characteristics. However, these materials present environmental challenges, including a high carbon footprint and issues with refractory wear.
In a pioneering industrial feasibility study conducted by RHI Magnesita and MIRECO at SWT, traditional fluxes were replaced with a high-alumina circular metallurgical additive (<10% CFP of usual additives) derived from recycled refractory material. Utilizing RHI Magnesita’s comprehensive metallurgical consulting and advanced e-tech slag modelling tools, the trials achieved an optimal balance between desulphurisation rate, additive application, slag disposal costs, and purging gas consumption. This innovative approach not only maintained effective desulphurisation within the same treatment time but also delivered significant cost savings—estimated at over €1 million per year—and reduced the overall carbon footprint.
Sustainable Impact and Future Outlook
This breakthrough reinforces the value of circular raw materials in the steelmaking process. By repurposing used refractory products, the new approach enables a reduction in the reliance on virgin inputs and supports closed-loop recycling. MIRECO further contributes to sustainability through its comprehensive range of eco-friendly additives and the “CERO Waste” service, which facilitates the reintegration of spent refractory materials into the supply chain. This service complies with the European Waste Framework Directive by optimising refractory collection, material sorting, and recycling to minimize landfill waste and decrease CO₂ emissions.
The partnership between Stahlwerk Thüringen, RHI Magnesita and MIRECO exemplifies how innovative process improvements and circular economy practices can drive both operational excellence and environmental stewardship in the steel industry. For those interested in a deeper dive into the trial specifics, technical details, and further discussion on efficiency optimisation, please refer to the full paper available here.
Embracing circular metallurgical additives not only bolsters the green steel initiative but also paves the way for a more sustainable, cost-effective future in steel production. If you are interested in circular metallurgical additives, please get in touch with a sales representative.