The influence of microwave treatment on the liberation of iron ore from the high phosphorus oolitic iron ore from Aswan region, Egypt was studied. The effect of microwave power, exposure time and grain size on the liberation of iron ore was investigated. The microfractures and cracks of the samples were characterized before and after microwave treatments. The heating rate of high phosphorus oolitic iron ore was studied. Crystallinity of hematite was characterized before and after microwave pretreatment. The results indicated that intergranular fractures formed between the gangues (fluorapatite and chamosite) and hematite after microwave treatment, leading to improved liberation of iron ore and a significant reduction in comminution energy. Percentages of fraction ≤ -0.125 mm increased from 46.6% to 59.76% with increased exposure time from 0 to 60 seconds. The heating rate of iron ore showed that microwave treatment was less efficient at smaller particle sizes for a fixed applied power density. Crystallinity of hematite increased with the microwave exposure time.
KeywordsMicrowave TreatmentHigh Phosphorus Oolitic Iron OreLiberation
Flügel, E. (2010) Microfacies of Carbonate Rocks. Analysis, Interpretation and Application. Springer-Verlag, Berlin.
Manieh, A.A. (1984) Oolite Liberation of Oolitic Iron Ore, Wadi Fatima, Saudi Arabia. International Journal of Mineral Processing, 13, 187-192. http://dx.doi.org/10.1016/0301-7516(84)90002-4
Champetier, Y., Hamdadou, E. and Hamdadou, M. (1987) Examples of Biogenic Support of Mineralization in Two Oolitic Iron Ores—Lorraine (France) and Garadjebilet (Algeria). Sedimentary Geology, 51, 249-255. http://dx.doi.org/10.1016/0037-0738(87)90050-9
Ozdemir, O. and Deutsch, E.R. (1984) Magnetic Properties of Oolitic Iron Ore on Bell Island, New Found Land. Earth and Planetary Science Letters, 69, 427-441. http://dx.doi.org/10.1016/0012-821X(84)90201-2
Abro, M.M., Pathan, A.G. and Mallah, A.H. (2011) Liberation of Oolitic Hematite Grains from Iron Ore, Dilband Mines Pakistan. Mehran University Research, Journal of Engineering Technology, 30, 329-338.
Li, K., Ni, W., Zhu, M., Zheng, M. and Li, Y. (2011) Iron Extraction from Oolitic Iron Ore by a Deep Reduction Process. Journal of Iron and Steel Research International, 18, 9-13. http://dx.doi.org/10.1016/S1006-706X(11)60096-4
El Sharkawi, M.A., El Aref, M.M. and Mesaed, A.A. (1996) Stratigraphic setting and Paleoenvironment of the Conician-Santonian Ironstones of Aswan, South Egypt. Geological Society of Egypt, 243-278
El Aref, M.M., El Sharkawi, M.A. and Mesaed, A.A. (1996) Depositional and Diagenetic Microfabric Evolution of the Cretaceous Oolitic Ironstone of Aswan, Egypt. Geological Society of Egypt, 279-312.
Song, S., Campos-Toro, E. F. and Valdivieso, A. L. (2013) Formation of Micro-Fractures on an Oolitic Iron Ore under Microwave Treatment and its Effect on Selective Fragmentation. Journal of Powder Technology, 243, 155-160. http://dx.doi.org/10.1016/j.powtec.2013.03.049
Ji, J. (2003) Study on Dephosphorization Technology for High-Phosphorus Iron Ore. Mining & Metallurgy. 12, 33-37.
Xia, W.T., Ren, Z.D. and Gao, Y.F. (2011) Removal of Phosphorus from High Phosphorus Iron Ores by Selective HCl Leaching Method. International Journal of Iron and Steel Research, 18, 1-4. http://dx.doi.org/10.1016/S1006-706X(11)60055-1
Cheng, C.Y., Misra, V.N., Clough, J. and Muni, R. (1999) Dephosphorisation of Western Australian Iron Ore by Hydrometallurgical Process. Minerals Engineering, 12, 1083-1092. http://dx.doi.org/10.1016/S0892-6875(99)00093-X
Wang, J.C., Shen, S.B., Kang, J.H., Li, H.X. and Guo, Z.C. (2010) Effect of Ore Solid Concentration on the Bioleaching of Phosphorus from High-Phosphorus Iron Ores Using Indigenous Sulfur-Oxidizing Bacteria from Municipal Wastewater. Process Biochemistry, 45, 1624-1631.
Delvasto, P., Valverde, A., Ballester, A., Munoz, J.A., Gonzalez, F. and Blazquez, M.L. (2008) Diversity and Activity of Phosphate Bioleaching Bacteria from a High-Phosphorus Iron Ore. Hydrometallurgy, 92, 124-129. http://dx.doi.org/10.1016/j.hydromet.2008.02.007
Yu, Y.F. and Qi, C.Y. (2011) Magnetizing Roasting Mechanism and Effective Ore Dressing Process for Oolitic Hematite Ore. Journal of Wuhan University of Technology. Materials Science Ed., 26, 176-181. http://dx.doi.org/10.1007/s11595-011-0192-6
Tang, H.Q., Guo, Z.C. and Zhao, Z.L. (2010) Phosphorus Removal of High Phosphorus Iron Ore by Gas-Based Reduction and Melt Separation. International Journal of Iron and Steel Research, 17, 1-6. http://dx.doi.org/10.1016/S1006-706X(10)60133-1
Fisher-White, M.J., Lovel, R.R. and Sparrow, G.J. (2012) Phosphorus Removal from Goethitic Iron Ore with a Low Temperature Heat Treatment and a Caustic Leach. ISIJ International, 52, 797-803.
Kumar, P., Sahoo, B.K., De, S., Kar, D.D., Chakraborty, S. and Meikap, B.C. (2010) Iron Ore Grindabilityim-Provement by Microwave Pretreatment. Journal of Industrial and Engineering Chemistry, 16, 805-812. http://dx.doi.org/10.1016/j.jiec.2010.05.008
Tromans, D. (2008) Mineral Comminution: Energy Efficiency Considerations. Minerals Engineering, 21, 613-620. http://dx.doi.org/10.1016/j.mineng.2007.12.003
Wang, E., Shi, F. and Manlapig, E. (2012) Mineral Liberation by High Voltage Pulses and Conventional Comminution with Same Specific Energy Levels. Minerals Engineering, 27-28, 28-36. http://dx.doi.org/10.1016/j.mineng.2011.12.005
Ali, A.Y. and Bradshaw, S.M. (2009) Quantifying Damage around Grain Boundaries in Microwave Treated Ores. Chemical Engineering and Processing: Process Intensification, 48, 1566-1573. http://dx.doi.org/10.1016/j.cep.2009.09.001
Roussy, G. and Pearce, J.A. (1995) Foundations and Industrial Applications of Microwave and Radiofrequency Fields-Physical and Chemical Processes, Chapters 10, 11, 12. Wiley, Hoboken.
Haque, K.E. (1999) Microwave Energy for Mineral Treatment Processes—A Brief Review. International Journal of Mineral Processing, 57, 1-24. http://dx.doi.org/10.1016/S0301-7516(99)00009-5
Whittles, D.N., Kingman, S.W. and Reddish, D.J. (2003) Application of Numerical Modelling for Prediction of the Influence of Power Density on Microwave-Assisted Breakage. International Journal of Mineral Processing, 68, 71-91. http://dx.doi.org/10.1016/S0301-7516(02)00049-2
Jones, D.A., Kingman, S.W., Whittles, D.N. and Lowndes, I.S. (2007) The Influence of Microwave Energy Delivery Method on Strength Reduction in Ore Samples. Chemical Engineering and Processing: Process Intensification, 46, 291-299. http://dx.doi.org/10.1016/j.cep.2006.06.009
Fitzgibbon, K. and Veasey, T. (1990) Thermally Assisted Liberation—A Review. Minerals Engineering, 3, 181-185. http://dx.doi.org/10.1016/0892-6875(90)90090-X
Kingman, S.W. and Rowson, S.A. (1998) Microwave Treatment of Minerals—A Review. Minerals Engineering, 11, 1081-1087. http://dx.doi.org/10.1016/S0892-6875(98)00094-6
Tang, H.Q., Wang, J.W., Guo, Z. and Ou, T. (2013) Intensifying Gaseous Reduction of High Phosphorus Iron Ore Fines by Microwave Pretreatment. International Journal of Iron and Steel Research, 20, 17-23. http://dx.doi.org/10.1016/S1006-706X(13)60091-6
Amankwah, R.K., Khan, A.U., Pickles, C.A. and Yen, W.T. (2005) Improved Grindability and Gold Liberation by Microwave Pretreatment of a Free Milling Gold Ore. Mineral Processing and Extractive Metallurgy, 114, 30-36. http://dx.doi.org/10.1179/037195505X28447
Kingman, S.W., Corfield, G. and Rowson, N.A. (1999) Effect of Microwave Radiation upon the Mineralogy and Magnetic Processing of a Massive Norwegian Ilmenite. Magnetic and Electrical Separation, 9, 131-148.
Kingman, S.W. and Rowson, N.A. (2000) The Effect of Microwave Radiation on the Magnetic Properties of Minerals. Journal of Microwave Power and Electromagnetic Energy, 35, 141-150.
Kingman, S.W., Vorster, W. and Rowson, N.A. (2000) The Influence of Mineralogy on Microwave Assisted Grinding. Minerals Engineering, 13, 313-327. http://dx.doi.org/10.1016/S0892-6875(00)00010-8
Aguilar-Garib, J.A. (2011) Thermal Microwave Processing of Materials. In: Grundas, S., Ed., Advances in Induction and Microwave Heating of Mineral and Organic Materials, InTech. http://www.intechopen.com/books/advances-in-induction-and-microwaveheating-of-mineral-and-organic-materials/thermal-microwave-processing-of-materials
Barani, K., Koleini, S.M.J. and Rezaei, B. (2011) Magnetic Properties of an Iron Ore Sample after Microwave Heating. Separation and Purification Technology, 76, 331-336. http://dx.doi.org/10.1016/j.seppur.2010.11.001
Ali, A.Y. and Bradshaw, S.M. (2010) Bonded Particle Modelling of Microwave Induced Damage in Ore Particles. Minerals Engineering, 23, 780-790. http://dx.doi.org/10.1016/j.mineng.2010.05.019
Salsman, J.B., Williamson, R.L., Tolley, W.K. and Rice, D.A. (1996) Short Pulse Microwave Treatment of Disseminated Sulphide Ores. Minerals Engineering, 9, 43-54. http://dx.doi.org/10.1016/0892-6875(95)00130-1
Chen, T.T., Dutrizac, J.E., Haque, K.E., Wyslouzil, W. and Kashyap, S. (1984) The Relative Transparency of Minerals to Microwave Radiation. Canadian Metallurgical Quarterly, 23, 349-351. http://dx.doi.org/10.1179/cmq.1984.23.3.349
Kobusheshe, J. (2010) Microwave Enhanced Processing of Ores. Ph.D. Thesis, the University of Nottingham, Nottingham.