EEC 2026 - 14th European Electric Steelmaking Conference & EMECR 2026 - 5th International Conference on Energy and Material Efficiency and CO2 Reduction in the Steel Industry

Implementation of recycled Zirconia in slag band layer of submerged entry nozzle

12 May 2026, 15:40

20m

Porta room

Oral Presentation EEC 3.D Recycling and circular economy in steelmaking Slag control and refractories II

Speaker

Dr Suresh Kodukula (RHI Magnesita)

Description

Refractory recycling has emerged as a key strategy in reducing the environmental impact of the steel and cement industries, where spent refractories often pose significant disposal challenges due to the presence of hazardous components such as bauxite, copper, magnesite, and zirconia, chrome-bearing materials. In line with its sustainability roadmap, RHI Magnesita is actively pursuing circular economy solutions to lower the carbon footprint of refractory products. Recycling not only conserves critical raw materials but also offers substantial CO₂ savings—up to 60% for mixed refractory linings and nearly 90% for unshaped products—compared to primary raw materials.

This study presents a practical example of integrating recycled material into production: the partial substitution of Zirconia virgin raw material (ZVM) with Zirconia containing recycling material (ZRM) material in the sub-entry nozzle (SEN) slag band formulation containing approximately 11% recycled content. Material integrity and thermomechanical properties were preserved, importantly with similar corrosion resistance to mould powder comparable to that of the standard product produced using virgin raw materials. Subsequently, trials conducted using components produced with the recycled formulation confirmed consistent and similar performance during continuous casting operations, validating the feasibility of high-quality refractory recycling in practice. This work underlines the strategic importance of recycling in refractories, not only from an environmental perspective but also for securing long-term raw material supply.

References
1. L.Horckmans, P. Nielsen, P. Dierckx, A.Ducastel, Recycling of refractory bricks used in basic steelmaking: A review Resources, Conseravation & Recycling 140(2019) 297-304.
2. J.Madias, A review on recycling refractories for the Iron and Steel Industry, AISTech 2018 Proceedings.
3. M.Moraes, A.Leitner, G.Nogueira, B.Zocratto, S.Heid and J.Mühlhäußer, Technical Challenges for Refractory Recycling and Innovative Processing Solutions, Bulleting 2023 pp33-38.