Recycling Rubber Tyres and Waste Plastics in EAF Steelmaking

Electric Arc Furnace (EAF) steelmaking uses different carbon based materials as foaming agents. Depending on cost and availability, anthracite and metallurgical coke are among the conventional injecting materials. Considering the energy and green house gas emissions requirements, alternative carbon sources are put on the spot to replace, at least partially, the conventional materials, i.e. waste materials such as rubber and high density polyethylene (HDPE) plastics may react with gas and slag phases resulting in devolatilization, combustion and iron oxide reduction reactions. The addition of waste tyres and waste plastics in EAF steelmaking has been studied in detail by our groups at UNSW and OneSteel is developing a method for EAFs to use blends of different proportions of rubber/HDPE plastics and coke as a slag foaming agent. Initially, laboratory investigations were carried out to establish the feasibility of carbon and polymer blends as foaming agents. The enhanced slag foaming performance compared to coke was found to be in good accordance with the results obtained in the laboratory indicating an increased slag volume when using polymeric blends. Following the successful installation of materials handling systems at both plants, the use of a rubber and coke blend is no longer considered a trial and is instead standard practice.

[1]  Miss A.O. Penney.  (b) , 1974, The New Yale Book of Quotations.

[2]  P. Koshy,et al.  Carbon/Slag Interactions between Coke/Rubber Blends and EAF Slag at 1 550°C , 2009 .

[3]  V. Sahajwalla,et al.  The Influence of Ash Impurities on Interfacial Reactions between Carbonaceous Materials and EAF Slag at 1550°C , 2009 .

[4]  B. Dawson,et al.  INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC) , 2008 .

[5]  E. Kwon,et al.  Beneficial Use of Waste Tires: An Integrated Gasification and Combustion Process Design via Thermo-Gravimetric Analysis (TGA) of Styrene–Butadiene Rubber (SBR) and Poly-Isoprene (IR) , 2007 .

[6]  V. Sahajwalla,et al.  Novel Sessile Drop Software for Quantitative Estimation of Slag Foaming in Carbon/Slag Interactions , 2007 .

[7]  B. Gros,et al.  Charging used tyres in the EAF as a substitute for carbon: a success story for LME and Industeel Belgium , 2007 .

[8]  Manfred Schingnitz,et al.  Results and trends on the injection of plastics and ASR into the blast furnace , 2006 .

[9]  P. Hayes,et al.  Kinetics of Reduction of FeO from Slag by Graphite and Coal Chars , 2005 .

[10]  S. Jahanshahi,et al.  Physicochemical properties of foaming slags , 2004 .

[11]  Giacomo M. Bisio,et al.  Heat transfer, energy saving and pollution control in UHP electric-arc furnaces , 2000 .

[12]  T. Nagasaka,et al.  Interfacial kinetics of hydrogen with liquid slag containing iron oxide , 2000 .

[13]  Michitaka Sato,et al.  Development of Waste Plastics Injection Process in Blast Furnace , 2000 .

[14]  Thomas de Quincey.  [C] , 2000, The Works of Thomas De Quincey, Vol. 1: Writings, 1799–1820.

[15]  S. Hara,et al.  Slag-foaming Phenomenon in Pyrometallurgical Processes , 1992 .

[16]  G. Menges,et al.  Verschmutzte Kunststoffalbfälle werden zu wachsartigen Substanzen , 1992 .