Production of pig iron from red mud waste fines using thermal plasma technology

Abstract

Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite (fixed carbon, 99%) as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.

Keywords

pig iron / waste utilization / red mud / smelting / dolomite / limestone / thermal plasma

References

[1] Chandwani H.K., Vishwanathan V., Goyal R.N., Prasad P.M. Recovery of iron and metal values from red mud possibilities in Indian scenario. NML Tech. J., 1997, 39(3): 117.

[2] Kumar R., Srivastava J.P. Premchand, Utilisation of iron values of red mud for metallurgical applications. Environ. Waste Manage., 1998, 30, 108.

[3] Agrawal A., Sahu K.K., Pandey B.D. Solid waste management in non-ferrous industries in India. Resour. Conserv. Recycl., 2004, 42, 99

[4] Andrejcak M., Soucy G. Patent review of red mud treatment-product of Bayer process. Acta Metall. Slovaca, 2004, 10(4): 347.

[5] Erçağ E., Apak R. Furnace smelting and extractive metallurgy of red mud: recovery of TiO₂, Al₂O₃ and pig iron. J. Chem. Technol. Biotechnol., 1997, 70, 241

[6] Kumar S., Kumar R., Bandopadhyay A. Innovative methodologies for the utilization of wastes from metallurgical and allied industries. Resour. Conserv. Recycl., 2006, 48, 301

[7] Mymrin V.A., Vazquez-Vaamande A.J. Red mud of aluminum production waste as basic component of new construction materials. Waste Manage. Res., 2001, 19, 465

[8] Jayasankar K., Mohapatra S., Routray S.K., Gumaste J.L., Mukherjee P.S. Thermal plasma processing for the production of pig iron from various sources. High Temp. Mater. Process., 2009, 28, 1

[9] Galgali R.K., Ray H.S., Chakrabarti A.K. A study on carbothermic reduction of ilmenite ore in a plasma reactor. Metall. Mater. Trans. B, 1998, 29(6): 1175

[10] Schwertmann U., Cornell R.M. Iron Oxides in the Laboratory: Preparation and Characterization, 1991 2nd ed New York, Wiley VCH

[11] Das T., Ghosh M.K., Chaudury G.R. Assessment of the significant parameters influencing the bio-oxidation and bio-precipitation of the iron from industrial leach liquor. Trans. Inst. Min. Metall. Sect. C, 2005, 114, 57.

[12] Pourbaix M. Atlas of Electrochemical Equilibria in Aqueous Solutions, 1974, Oxford, National Association of Corrosion Engineers, Pergamon Press

[13] Rath S.S., Jayasankar K., Satapathy B.K., Mishra B.K., Mukherjee P.S. Kinetics and statistical behaviour of iron recovery from red mud using plasma arc furnace. High Temp. Mater. Process., 2011, 30, 211.