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Dissociation behavior and structural of ilmenite ore by microwave irradiation
Applied Surface Science 258 (2012) 4826–4829
Contents lists available at SciVerse ScienceDirect
Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc
Letter to the Editor Dissociation behavior and structural of ilmenite ore by microwave irradiation
a r t i c l e
i n f o
Keywords: Microwave irradiation Ilmenite ore Crystalline compound Surface chemical functional groups Microstructure
a b s t r a c t In this study, the influences of microwave irradiation on the dissociation behavior and structural characterization of ilmenite ore were systematically investigated. The crystal structures, microstructure, and surface chemical functional groups of the samples were characterized before and after microwave irradiation using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR), respectively. Treatment variables, microwave power and exposure time, had statistically significant effects on the dissociation behavior and structural characterization of ilmenite ore. The XRD, SEM and FT-IR analysis results indicated that the crystal structures, microstructure, and surface chemical functional groups of microwave treated ilmenite ore are better than those of ilmenite ore. © 2012 Elsevier B.V. All rights reserved.
1. Introduction For over past decades, many researchers have investigated the application of microwave irradiation to minerals, and extractive metallurgy. Microwaves are a specific category of radio waves that cover the frequency range 300 MHz to approximately 300 GHz [1,2]. Compared to conventional heating methods, the major advantages of using microwaves heating for industrial processing are rapid heat transfer, volumetric and selective heating, compactness of equipment, speed of switching on and off, and pollutionfree environment as there are no products of combustion [3–5]. Additional advantages include greater control of the microwave heating process, no direct contact between the heating source and heated materials, and reduced equipment size and waste. Hence, microwave energy is used in industry for various processes such as drying, calcining, roasting, and smelting [6–11]. The ore pretreatment is one of the most important stages of the processes of comminution [12]. Common pretreatment processes consume a large amount of energy to liberate minerals from ores, making these a major concern [13–18]. Compared with the conventional ore pretreatment methods, the microwave irradiation method needs much less energy, gives higher minerals recovery, and is very suitable for application in commercial-scale operation [19–22]. Whittles et al. [23] investigated the effect of power density on the microwave treatment of ores and found that the power density is an important factor in microwave treatment of ores. It decreases energy consumption and improves the efficiency. Kingman et al. [24] investigated the influence of high electric field strength microwave energy on copper carbonatite ore and showed that even very short exposures time can lead to significant reduction in ore strength as determined by point load tests. The use of microwave treatment to enhance the liberation of gold for subsequent recovery by gravity separation techniques has been investigated by Amankwah et al. [25]. 0169-4332/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2011.12.121
In the present work, the ilmenite ore was pretreated using microwave irradiation. Effect of the microwave power and exposure time on crystal structures, microstructure, and surface chemical functional groups were mainly studied. The crystal structures, microstructure and surface chemical functional groups of ilmenite ore before and after microwave irradiation were also analyzed. 2. Experimental 2.1. Materials Ilmenite ore from Titanium Company of Panzhihua Steel and Iron Corporation, Sichuan, China, was used as raw material. The chemical composition was listed in Table 1. 2.2. Characterization The powder X-ray diffraction (XRD, D/Max 2200, Rigaku, Japan) using CuK␣ radiation was employed to identify the crystalline phase of the ilmenite ore and sample after microwave irradiation. The SEM images and elemental mapping of the ilmenite ores were observed with scanning electron microscopy (SEM, XL30ESEMTMP, Philips, Holland). The elements of samples were identified by energy-dispersive X-ray spectroscopy (EDAX, USA). Infrared spectra were recorded using a FT-IR spectrometer (8700, Nicolet, USA). In this experiment, the particle size distribution of samples was measured by the technique based on laser diffraction and scattering using a laser diffraction analyzer (Mastersize2000, Malvern, UK). 2.3. Procedure Prior to the use, ilmenite ore was loaded on a ceramics boat, which was introduced inside a microwave muffle furnace. The
Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829 Table 1 Chemical composition of the ilmenite ore (wt.%).
70 MgO
Al2 O3
6.48
7.12
3.33
Intensity/CPS
1,2 4
4 5
2000
3 1
2
1 2
1-Ilmenite 2-Magnetite 3-Diopside 4-Kaersutite 5-Silicon Oxide 6-Forsterite
(b) (a)
40
2
6
6
11,2
(b)
30
1
4000
3000
2000
1000
0
Wavenumbers/cm-1
1000 1
0
50
3434.2
331
T/%
4000
60
572.3
CaO
20.38
465.3
SiO2
15.71
1067.1 976.9
TiO2
30.67
1641.2
TFe
3000
4827
0
2
2
1 2 2
20
40
Fig. 2. FT-IR spectra of the ilmenite ore: (a) ilmenite ores; (b) microwave treated samples.
(a) 60
80
100
2-Theta/deg
microwave power levels were varied at 3 kW and the exposure time was set at 10, 20, and 30 s, respectively. The sample was naturally cooled in the furnace to room temperature. After microwave irradiation, the treated samples were ground for 60 s by using the laboratory sample crusher.
magnetite reference XRD patterns. It can be seen from Fig. 1(b) that the microwave treated ilmenite ore has peak of phase more than that of raw ore. By comparing with Fig. 1(a), with the increase in microwave irradiation time, the peak intensity of magnetite and ilmenite increases, and the peaks for impurities, mainly magnesium oxide, calcium oxide, and other gangues appear [26]. The results indicates that after microwave irradiation at 3 kW and the time was set at 30 s, the structure of the ilmenite ore has dissociated into the principal valuable minerals and more gangue monomer.
3. Results and discussion
3.2. Characterization by FT-IR
3.1. Characterization by XRD
The surface chemical functional groups of the samples were characterized before and after microwave irradiation using FTIR and the results are shown in Fig. 2. For the FT-IR spectra of the ilmenite ore in Fig. 2(a), absorption bands at 3434.2, 1641.2, 1067.1, 976.9 and 465.3 cm−1 are observed in the spectrum. The band at 3434.2 and 1067.1 cm−1 have been assigned to the bending
Fig. 1. The XRD pattern of the ilmenite ore: (a) ilmenite ores; (b) microwave treated samples.
XRD measurements were conducted to distinguish the crystal structure between the ilmenite ores and microwave treated samples as shown in Fig. 1. It is found that the main phase of Fig. 1(a) is ilmenite and several peaks of it match well with those of the
Fig. 3. SEM image of the ilmenite ore after microwave irradiation: (a) 2000×; (b) 500×; (c) 200×; (d) 50×.
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Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829
Fig. 4. EDAX spectrum of the ilmenite ore after microwave irradiation: (a) SEM; (b) District 1; (c) District 2.
mode of hydroxyl groups adsorbed on the samples surface. The band at 1624.3 cm−1 can be assigned to H2 O adsorbed on the surface of the ilmenite ores. The band at 465.3 cm−1 can be assigned to the stretching vibrations of octahedral metal ion in the units [27,28]. The FT-IR spectrum of the microwave treated ilmenite ore at microwave power of 3 kW and microwave irradiation time of 30 s is shown in Fig. 2(b). As can be seen from Fig. 2(b), the most obvious change in the spectrum is that the bands at 3434.2, 1641.2 and 1067.1 cm−1 become barely visible. This vibration mode compared with the one of the ilmenite ores at 465.3 cm−1 shows a slight blue-shift of the stretching vibrations of the band toward higher frequency [29].
irradiation, and the gangue inside the minerals were separated, which was caused by differential expansion between mineral and gangue under microwave irradiation. According to SEM analysis result, EDAX analysis of valuable minerals and gangue minerals were carried out to know the compositional variation between them, the result is represented in Fig. 4. It was observed from Fig. 4 that the ilmenite ore consists of Fe and Ti, and minor amounts of Al, Mg, Ca and Si. Titanium and iron contents increase from gangue minerals to valuable minerals, while aluminum, magnesium, calcium, and silicon content decreases [26].
3.4. Characterization by particle-size distribution 3.3. Characterization by SEM The ilmenite ore was pretreated by microwave irradiation at microwave power of 3 kW and the microwave heating time of 30 s. It was characterized by SEM and EDAX techniques, and the results as shown in Figs. 3 and 4, respectively. From the SEM image in Fig. 3, the results indicated that the crack in the grain boundaries of ilmenite ore appeared after being pretreated by microwave
Fig. 5 shows the particle size distribution of the ilmenite ore and microwave treated ilmenite ore. It can be seen from Fig. 5, the average particle diameter (d50 ) decrease gradually from about 54.75 to 16.76 m with the increase of microwave irradiation time from 0 to 30 s. The results indicate that microwave irradiation techniques can be applied effectively and efficiently to the pretreatment processing of ilmenite ore.
Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829
Distribution rate/%
100
80
Ilmenite ore 10s 20s 30s
60
40
20
0 0.01
0.1
1
10
100
1000
Particle size/μm Fig. 5. Particle size distributions of the ilmenite ore before and after microwave irradiation.
4. Conclusion The present study, the dissociation behavior and structural characterization of ilmenite ore under microwave irradiation was systematically investigated. XRD analysis showed the better crystalline compound of the microwave treated ilmenite ore, SEM analysis showed the good microstructure in microwave treated sample and FT-IR analysis showed the better surface chemical functional groups at the treated minerals surface. Microwave irradiation process of ilmenite ore has a potential to provide a new method to treat ilmenite ore with high efficiency and low energy consumption. Acknowledgments Financial supports from the National Natural Science Foundation of China (no. 51090385), and the National Basic Research Program of China (no. 2007CB613606) were sincerely acknowledged. References [1] X.G. Meng, Y.Z. Wan, Q.Y. Li, J. Wang, H.L. Luo, Appl. Surf. Sci. 257 (2011) 10808–10814. [2] L. Li, X.M. Qin, G.B. Wang, L.M. Qi, G.P. Du, Z.J. Hu, Appl. Surf. Sci. 257 (2011) 8006–8012. [3] W. Li, J.H. Peng, L.B. Zhang, Z.B. Zhang, L. Li, S.M. Zhang, S.H. Guo, Hydrometallurgy 92 (2008) 79–85. [4] R. Marx Nirmal, K. Pandian, K. Sivakumar, Appl. Surf. Sci. 257 (2011) 2745–2751. [5] G. Chen, J. Chen, J.H. Peng, R.D. Wang, Trans. Nonferrous Met. Soc. China 20 (2010) s198–s204. [6] J.W. Walkiwicz, G. Kazonich, S.L. McGill, Miner. Metall. Process. 5 (1988) 39–42. [7] R.K. Amankwah, C.A. Pickles, Miner. Eng. 22 (1999) 1095–1101. [8] M. Huang, J.H. Peng, J.J. Yang, J.Q. Wang, Miner. Eng. 20 (2007) 92–94. [9] B.K. Sahoo, S. De, M. Carsky, B.C. Meikap, Ind. Eng. Chem. Res. 49 (2010) 3015–3021. [10] G. Chen, J. Chen, J.H. Peng, Metal. Int. 16 (2011) 59–62. [11] G. Chen, J.H. Peng, J. Chen, S.M. Zhang, High Temp. Mater. Process. 28 (2009) 165–174. [12] B.K. Sahoo, S. De, B.C. Meikap, Fuel Process. Technol. 92 (2011) 1920–1928. [13] P. Kumar, B.K. Sahoo, S. De, D.D. Kar, S. Chakraborty, B.C. Meikap, J. Ind. Eng. Chem. 16 (2010) 805–812. [14] G. Scott, S.M. Bradshaw, J.J. Eksteen, Int. J. Miner. Process. 85 (2008) 121–128.
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[15] S.W. Kingman, K. Jackson, S.M. Bradshaw, N.A. Rowoson, R. Greenwood, Powder Technol. 146 (2004) 176–184. [16] G. Chen, K. Xiong, J.H. Peng, J. Chen, Adv. Powder Technol. 21 (2010) 331–335. [17] Z.B. Zhang, Z.Y. Zhang, H. Niu, J.H. Peng, L.B. Zhang, W.W. Qu, H.J. Pan, Trans. Nonferrous Met. Soc. China 20 (2010) s182–s186. [18] P.A. Olubambi, J.H. Potgieter, J.Y. Hwang, S. Ndlovu, Hydrometallurgy 89 (2007) 127–135. [19] B.K. Sahoo, S. De, M. Carsky, B.C. Meikap, J. Ind. Eng. Chem. 17 (2011) 62–70. [20] K. Fukui, M. Katoh, T. Yamamoto, H. Yoshida, Adv. Powder Technol. 20 (2009) 35–40. [21] T.T. Chen, J.E. Dutrizac, K.E. Haque, W. Wyslouzil, S. Kashyap, Can. Metall. Q. 23 (1984) 349–351. [22] B.C. Meikap, N.K. Purohit, V. Mahadevan, J. Colloid Interface Sci. 281 (2005) 225–235. [23] D.N. Whittles, S.W. Kingman, D.J. Reddish, Int. J. Miner. Process. 68 (2003) 71–91. [24] S.W. Kingman, K. Jackson, A. Cumbane, S.M. Bradshaw, N.A. Rowson, R. Greenwood, Int. J. Miner. Process. 74 (2004) 71–83. [25] R.K. Amankwah, A.U. Khan, C.A. Pickles, W.T. Yen, Miner. Process. Extr. Metall. 114 (2005) C30–C36. [26] S.H. Guo, G. Chen, J.H. Peng, J. Chen, D.B. Li, L.J. Li, Trans. Nonferrous Met. Soc. China 21 (2011) 2122–2126. [27] G. Chen, J. Chen, J.H. Peng, C. Srinivasakannan, J. Alloys Compd. 509 (2011) L244–L247. [28] H.L. Ma, J.Y. Yang, Y. Dai, Y.B. Zhang, B. Lu, G.H. Ma, Appl. Surf. Sci. 253 (2007) 7497. [29] G. Chen, J. Chen, C. Srinivasakannan, J.H Peng, Appl. Surf. Sci., doi:10.1016/j.apsusc.2011.11.039.
Guo Chen a,b,∗∗ Jin Chen a,b Shenghui Guo a,b Jun Li a,b C. Srinivasakannan c Jinhui Peng a,b,∗ a Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, PR China b Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China c Chemical Engineering Program, The Petroleum Institute, P.O. Box 253, Abu Dhabi, United Arab Emirates ∗ Corresponding
author at: Kumming University of Science and Technology, Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, PR China. Tel.: +86 871 5138997; fax: +86 871 5138997. ∗∗ Corresponding author at: Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China. E-mail addresses: [email protected] (G. Chen), [email protected] (J. Peng)
7 October 2011 26 December 2011 29 December 2011 Available online 4 January 2012
Contents lists available at SciVerse ScienceDirect
Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc
Letter to the Editor Dissociation behavior and structural of ilmenite ore by microwave irradiation
a r t i c l e
i n f o
Keywords: Microwave irradiation Ilmenite ore Crystalline compound Surface chemical functional groups Microstructure
a b s t r a c t In this study, the influences of microwave irradiation on the dissociation behavior and structural characterization of ilmenite ore were systematically investigated. The crystal structures, microstructure, and surface chemical functional groups of the samples were characterized before and after microwave irradiation using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR), respectively. Treatment variables, microwave power and exposure time, had statistically significant effects on the dissociation behavior and structural characterization of ilmenite ore. The XRD, SEM and FT-IR analysis results indicated that the crystal structures, microstructure, and surface chemical functional groups of microwave treated ilmenite ore are better than those of ilmenite ore. © 2012 Elsevier B.V. All rights reserved.
1. Introduction For over past decades, many researchers have investigated the application of microwave irradiation to minerals, and extractive metallurgy. Microwaves are a specific category of radio waves that cover the frequency range 300 MHz to approximately 300 GHz [1,2]. Compared to conventional heating methods, the major advantages of using microwaves heating for industrial processing are rapid heat transfer, volumetric and selective heating, compactness of equipment, speed of switching on and off, and pollutionfree environment as there are no products of combustion [3–5]. Additional advantages include greater control of the microwave heating process, no direct contact between the heating source and heated materials, and reduced equipment size and waste. Hence, microwave energy is used in industry for various processes such as drying, calcining, roasting, and smelting [6–11]. The ore pretreatment is one of the most important stages of the processes of comminution [12]. Common pretreatment processes consume a large amount of energy to liberate minerals from ores, making these a major concern [13–18]. Compared with the conventional ore pretreatment methods, the microwave irradiation method needs much less energy, gives higher minerals recovery, and is very suitable for application in commercial-scale operation [19–22]. Whittles et al. [23] investigated the effect of power density on the microwave treatment of ores and found that the power density is an important factor in microwave treatment of ores. It decreases energy consumption and improves the efficiency. Kingman et al. [24] investigated the influence of high electric field strength microwave energy on copper carbonatite ore and showed that even very short exposures time can lead to significant reduction in ore strength as determined by point load tests. The use of microwave treatment to enhance the liberation of gold for subsequent recovery by gravity separation techniques has been investigated by Amankwah et al. [25]. 0169-4332/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2011.12.121
In the present work, the ilmenite ore was pretreated using microwave irradiation. Effect of the microwave power and exposure time on crystal structures, microstructure, and surface chemical functional groups were mainly studied. The crystal structures, microstructure and surface chemical functional groups of ilmenite ore before and after microwave irradiation were also analyzed. 2. Experimental 2.1. Materials Ilmenite ore from Titanium Company of Panzhihua Steel and Iron Corporation, Sichuan, China, was used as raw material. The chemical composition was listed in Table 1. 2.2. Characterization The powder X-ray diffraction (XRD, D/Max 2200, Rigaku, Japan) using CuK␣ radiation was employed to identify the crystalline phase of the ilmenite ore and sample after microwave irradiation. The SEM images and elemental mapping of the ilmenite ores were observed with scanning electron microscopy (SEM, XL30ESEMTMP, Philips, Holland). The elements of samples were identified by energy-dispersive X-ray spectroscopy (EDAX, USA). Infrared spectra were recorded using a FT-IR spectrometer (8700, Nicolet, USA). In this experiment, the particle size distribution of samples was measured by the technique based on laser diffraction and scattering using a laser diffraction analyzer (Mastersize2000, Malvern, UK). 2.3. Procedure Prior to the use, ilmenite ore was loaded on a ceramics boat, which was introduced inside a microwave muffle furnace. The
Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829 Table 1 Chemical composition of the ilmenite ore (wt.%).
70 MgO
Al2 O3
6.48
7.12
3.33
Intensity/CPS
1,2 4
4 5
2000
3 1
2
1 2
1-Ilmenite 2-Magnetite 3-Diopside 4-Kaersutite 5-Silicon Oxide 6-Forsterite
(b) (a)
40
2
6
6
11,2
(b)
30
1
4000
3000
2000
1000
0
Wavenumbers/cm-1
1000 1
0
50
3434.2
331
T/%
4000
60
572.3
CaO
20.38
465.3
SiO2
15.71
1067.1 976.9
TiO2
30.67
1641.2
TFe
3000
4827
0
2
2
1 2 2
20
40
Fig. 2. FT-IR spectra of the ilmenite ore: (a) ilmenite ores; (b) microwave treated samples.
(a) 60
80
100
2-Theta/deg
microwave power levels were varied at 3 kW and the exposure time was set at 10, 20, and 30 s, respectively. The sample was naturally cooled in the furnace to room temperature. After microwave irradiation, the treated samples were ground for 60 s by using the laboratory sample crusher.
magnetite reference XRD patterns. It can be seen from Fig. 1(b) that the microwave treated ilmenite ore has peak of phase more than that of raw ore. By comparing with Fig. 1(a), with the increase in microwave irradiation time, the peak intensity of magnetite and ilmenite increases, and the peaks for impurities, mainly magnesium oxide, calcium oxide, and other gangues appear [26]. The results indicates that after microwave irradiation at 3 kW and the time was set at 30 s, the structure of the ilmenite ore has dissociated into the principal valuable minerals and more gangue monomer.
3. Results and discussion
3.2. Characterization by FT-IR
3.1. Characterization by XRD
The surface chemical functional groups of the samples were characterized before and after microwave irradiation using FTIR and the results are shown in Fig. 2. For the FT-IR spectra of the ilmenite ore in Fig. 2(a), absorption bands at 3434.2, 1641.2, 1067.1, 976.9 and 465.3 cm−1 are observed in the spectrum. The band at 3434.2 and 1067.1 cm−1 have been assigned to the bending
Fig. 1. The XRD pattern of the ilmenite ore: (a) ilmenite ores; (b) microwave treated samples.
XRD measurements were conducted to distinguish the crystal structure between the ilmenite ores and microwave treated samples as shown in Fig. 1. It is found that the main phase of Fig. 1(a) is ilmenite and several peaks of it match well with those of the
Fig. 3. SEM image of the ilmenite ore after microwave irradiation: (a) 2000×; (b) 500×; (c) 200×; (d) 50×.
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Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829
Fig. 4. EDAX spectrum of the ilmenite ore after microwave irradiation: (a) SEM; (b) District 1; (c) District 2.
mode of hydroxyl groups adsorbed on the samples surface. The band at 1624.3 cm−1 can be assigned to H2 O adsorbed on the surface of the ilmenite ores. The band at 465.3 cm−1 can be assigned to the stretching vibrations of octahedral metal ion in the units [27,28]. The FT-IR spectrum of the microwave treated ilmenite ore at microwave power of 3 kW and microwave irradiation time of 30 s is shown in Fig. 2(b). As can be seen from Fig. 2(b), the most obvious change in the spectrum is that the bands at 3434.2, 1641.2 and 1067.1 cm−1 become barely visible. This vibration mode compared with the one of the ilmenite ores at 465.3 cm−1 shows a slight blue-shift of the stretching vibrations of the band toward higher frequency [29].
irradiation, and the gangue inside the minerals were separated, which was caused by differential expansion between mineral and gangue under microwave irradiation. According to SEM analysis result, EDAX analysis of valuable minerals and gangue minerals were carried out to know the compositional variation between them, the result is represented in Fig. 4. It was observed from Fig. 4 that the ilmenite ore consists of Fe and Ti, and minor amounts of Al, Mg, Ca and Si. Titanium and iron contents increase from gangue minerals to valuable minerals, while aluminum, magnesium, calcium, and silicon content decreases [26].
3.4. Characterization by particle-size distribution 3.3. Characterization by SEM The ilmenite ore was pretreated by microwave irradiation at microwave power of 3 kW and the microwave heating time of 30 s. It was characterized by SEM and EDAX techniques, and the results as shown in Figs. 3 and 4, respectively. From the SEM image in Fig. 3, the results indicated that the crack in the grain boundaries of ilmenite ore appeared after being pretreated by microwave
Fig. 5 shows the particle size distribution of the ilmenite ore and microwave treated ilmenite ore. It can be seen from Fig. 5, the average particle diameter (d50 ) decrease gradually from about 54.75 to 16.76 m with the increase of microwave irradiation time from 0 to 30 s. The results indicate that microwave irradiation techniques can be applied effectively and efficiently to the pretreatment processing of ilmenite ore.
Letter to the Editor / Applied Surface Science 258 (2012) 4826–4829
Distribution rate/%
100
80
Ilmenite ore 10s 20s 30s
60
40
20
0 0.01
0.1
1
10
100
1000
Particle size/μm Fig. 5. Particle size distributions of the ilmenite ore before and after microwave irradiation.
4. Conclusion The present study, the dissociation behavior and structural characterization of ilmenite ore under microwave irradiation was systematically investigated. XRD analysis showed the better crystalline compound of the microwave treated ilmenite ore, SEM analysis showed the good microstructure in microwave treated sample and FT-IR analysis showed the better surface chemical functional groups at the treated minerals surface. Microwave irradiation process of ilmenite ore has a potential to provide a new method to treat ilmenite ore with high efficiency and low energy consumption. Acknowledgments Financial supports from the National Natural Science Foundation of China (no. 51090385), and the National Basic Research Program of China (no. 2007CB613606) were sincerely acknowledged. References [1] X.G. Meng, Y.Z. Wan, Q.Y. Li, J. Wang, H.L. Luo, Appl. Surf. Sci. 257 (2011) 10808–10814. [2] L. Li, X.M. Qin, G.B. Wang, L.M. Qi, G.P. Du, Z.J. Hu, Appl. Surf. Sci. 257 (2011) 8006–8012. [3] W. Li, J.H. Peng, L.B. Zhang, Z.B. Zhang, L. Li, S.M. Zhang, S.H. Guo, Hydrometallurgy 92 (2008) 79–85. [4] R. Marx Nirmal, K. Pandian, K. Sivakumar, Appl. Surf. Sci. 257 (2011) 2745–2751. [5] G. Chen, J. Chen, J.H. Peng, R.D. Wang, Trans. Nonferrous Met. Soc. China 20 (2010) s198–s204. [6] J.W. Walkiwicz, G. Kazonich, S.L. McGill, Miner. Metall. Process. 5 (1988) 39–42. [7] R.K. Amankwah, C.A. Pickles, Miner. Eng. 22 (1999) 1095–1101. [8] M. Huang, J.H. Peng, J.J. Yang, J.Q. Wang, Miner. Eng. 20 (2007) 92–94. [9] B.K. Sahoo, S. De, M. Carsky, B.C. Meikap, Ind. Eng. Chem. Res. 49 (2010) 3015–3021. [10] G. Chen, J. Chen, J.H. Peng, Metal. Int. 16 (2011) 59–62. [11] G. Chen, J.H. Peng, J. Chen, S.M. Zhang, High Temp. Mater. Process. 28 (2009) 165–174. [12] B.K. Sahoo, S. De, B.C. Meikap, Fuel Process. Technol. 92 (2011) 1920–1928. [13] P. Kumar, B.K. Sahoo, S. De, D.D. Kar, S. Chakraborty, B.C. Meikap, J. Ind. Eng. Chem. 16 (2010) 805–812. [14] G. Scott, S.M. Bradshaw, J.J. Eksteen, Int. J. Miner. Process. 85 (2008) 121–128.
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Guo Chen a,b,∗∗ Jin Chen a,b Shenghui Guo a,b Jun Li a,b C. Srinivasakannan c Jinhui Peng a,b,∗ a Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, PR China b Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China c Chemical Engineering Program, The Petroleum Institute, P.O. Box 253, Abu Dhabi, United Arab Emirates ∗ Corresponding
author at: Kumming University of Science and Technology, Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, PR China. Tel.: +86 871 5138997; fax: +86 871 5138997. ∗∗ Corresponding author at: Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China. E-mail addresses: [email protected] (G. Chen), [email protected] (J. Peng)
7 October 2011 26 December 2011 29 December 2011 Available online 4 January 2012