Recycling of Rubber Tyres in Electric Arc Furnace Steelmaking: Carbon/Slag Reactions of Coke/Rubber Blends

• Published in: High temperature materials and processes 2012-10, Vol.31 (4-5), p.593-602
• Main Authors: Zaharia, M., Sahajwalla, V., Saha-Chaudhury, N., O'Kane, P., Fontana, A., Skidmore, C., Knights, D.
• Format: Article
• Language: English
• Subjects: EAF steelmaking; rubber tyres; slag foaming
• ISSN: 0334-6455; 2191-0324
• DOI: 10.1515/htmp-2012-0096

End of life tyres are discarded at an alarming rate reflecting the strength of developing countries economy and the intensity of trade and transportation. Conversely, environmental concerns are increasing the need for alternative materials in steelmaking industries. The solution to this problem involves the development of environmentally-friendly technologies that would utilize these waste products. The present study investigates carbon/slag reactions, including slag foaming and FeO reduction, for a range of coke/rubber blends. Off-gas emissions (CO and CO2) were monitored and correlated with dynamic changes in volume as a result of iron oxide rich EAF slag and carbon. The gaseous emissions from metallurgical coke showed lower concentrations in comparison to the emissions from the coke-rubber blends. With an increase of rubber in the blend, gaseous emissions were enhanced. Significant carbon/slag interactions occurred when coke/rubber blends were used, with associated iron oxide reductions within the slag phase. The quantitative estimation of the slag droplet volume was performed by using the Vt/Vo ratio as a measure of slag foaming. These results indicate that partial replacement of coke with rubber is not only viable, but efficient leading to improved interactions with EAF slag.