Recycling Waste Bakelite As A Carbon Resource In Ironmaking
James Ransford Dankwah, Emmanuel Baawuah
Key Words: Bakelite, Composite pellets, Infrared gas analyser, LECO carbon/sulphur analyser, LECO oxygen/nitrogen analyser, Extent of reduction.
Abstract: Bakelite is a 3-dimensional cross-linked network structured thermosetting polymer which is difficult to recycle after use. However, it contains high levels of carbon and CaCO3 that can be recovered for use as reductant and fluxing agent in ironmaking. In this work we report the use of post-consumer bakelite as reductant for the production of metallic iron from iron oxide in a horizontal tube furnace through the composite pellet approach.Gas emission studies were conducted by pyrolysing raw bakelite at different temperatures within the temperature range 1200-1600 °C in a horizontal tube furnace. Following this,composite pellets were then formed from mixtures of iron oxide and post-consumer bakelite.The iron oxide-bakelite composites were heated from room temperature to 1200 °C and then between 1200-1600 °C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared (IR) gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygen/nitrogen analyser. The extent of reduction after ten minutes was determined from the oxygen content. Gas emission studies revealed the emission of large volumes of the reductant gases CO and CH4along with CO2.It is further demonstrated that post-consumer bakelite is effective at reducing iron oxide to produce metallic iron.
 J.R. Dankwah, “Utilisation of end-of-life plastics/rubber tyres and their blends with metallurgical coke in EAF steelmaking: reduction of iron oxide”, PhD. Thesis, School of Materials Science and Engineering, University of New South Wales, Sydney, Australia, 2012.
 S. Kongkarat, “Recycling of Waste Polymers in Electric ArcFurnace Steelmaking: Slag/Carbon andSteel/Carbon Interactions”, PhD. Thesis, School of Materials Science and Engineering, University of New South Wales, Sydney, Australia, 2011.
 T. Matsuda, M. Hasegawa, A. Ikemura, K. Wakimoto, and M. Iwase, “Utilization of waste plastic for production of metallic iron, hydrogen and carbon monoxide without generating carbon dioxide”ISIJ Int.,vol. 48, pp. 1188-1196, 2008
 J.R. Dankwah, P. Koshy, N.M. Saha-Chaudhury, P. O'Kane, C. Skidmore, D. Knights, and V.Sahajwalla, “Reduction of FeO in EAF steelmaking slag by metallurgical coke and waste plastics blends”, ISIJ Int.,vol. 51,no. 3, p. 498-507, 2011
 M. Zaharia, Reactions of waste rubber tyres and polypropylene plastics withgases and electric arc furnace steelmaking slags, Ph.D. Thesis, The Universityof New South Wales, Sydney, Australia
 Y.Ueki, R.Mii, K.Ohno, T.Maeda, K.Nishioka and M.Shimizu, “Reactionbehaviour during heating waste plastic materials and iron oxide composites”,ISIJ Int., vol. 48, No.12, pp. 1670-1675, 2008
 M.Zaharia, V.Sahajwalla, R.Khanna, P.Koshy and P.O’Kane, “Carbon/slag interactions between coke/rubber blends and EAF slag at 1550ºC”, ISIJ Int., vol. 49, No.10, pp. 1513-1521, 2009
 D.Wagner, O.Devisme, F.Patisson and D. Ablitzer, “A laboratory study of the reduction of iron oxides by hydrogen” Sohn International Symposium, 27-31 Aug., San Diego, ed., by: Kongoli, F., and Reddy, R.G., TMS, 2, 111-120, 2006