Dissolution of Rare Earth Elements from Coal Fly Ash Particles in a Dilute H2SO4 Solvent

Abstract

Recently, the worldwide supply of rare earth element (REE) resources will be severely restricted. On the other hand, coal fly ash particles emitted from coal-fired electric power plants contain relatively high concentrations of REEs. The contents of REEs in coal fly ash are regularly several hundreds of ppmw. In order to extract and recover REEs from coal fly ash particles, as a first step, we have investigated their dissolution behavior in a dilute H2SO4 solvent. The REE content of coal fly ash specimens has been precisely determined, and their presence in the ash component of the original coal and their enrichment in coal fly ash particles during coal combustion have been suggested. REEs in coal fly ash dissolve gradually in H2SO4 over time, and this implies two types of occurrences of the REEs in coal fly ash particles. By applying the unreacted core model to the dissolution behavior of REEs in a H2SO4 solvent, we can explain both types of occurrences.

Share and Cite:

S. Kashiwakura, Y. Kumagai, H. Kubo and K. Wagatsuma, "Dissolution of Rare Earth Elements from Coal Fly Ash Particles in a Dilute H2SO4 Solvent," Open Journal of Physical Chemistry, Vol. 3 No. 2, 2013, pp. 69-75. doi: 10.4236/ojpc.2013.32009.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] Japan Coal Energy Center, “Coal Ash Database”. http://www.jcoal.or.jp/coalash/coalash.html
[2] Societies of Civil Engineers, “The Technologies about Effective Utilization for Coal Fly Ash Aiming for the Sound Material-Cycle Society,” Japan, 2003. http://www.jsce.or.jp/committee/enedobo/text/03.pdf
[3] Ministry of the Environment, “Environmental Basic Act,” Japan, 1993. http://law.e-gov.go.jp/htmldata/H05/H05HO091.html
[4] M. Xu, R. Yan, C. Zheng, Y. Qiao, J. Han and C. Sheng, “Status of Trace Element Emission in a Coal Combustion Process: A Review,” Fuel Processing Technology, Vol. 85, No. 2-3, 2003, pp. 215-237.
[5] Ministry of the Environment, “Fundamental Law for Establishing a Sound Material-Cycle Society,” Japan, 2000. http://law.e-gov.go.jp/htmldata/H12/H12HO110.html
[6] Ministry of the Environment, “Soil Contamination Countermeasures Act,” Japan, 2002. http://law.e-gov.go.jp/htmldata/H14/H14HO053.html
[7] S. Kashiwakura, H. Kubo, Y. Kumagai, H. Kubo, K. Matsubae-Yokoyama, K. Nakajima and T. Nagasaka, “Removal of Boron from Coal Fly Ash by Washing with HCl Solution”, Fuel, Vol. 88, No. 7, 2009, pp. 1245-1250. doi:10.1016/j.fuel.2008.12.027
[8] S. Kashiwakura, H. Ohno, K. Matsubae-Yokoyama, Y. Kumagai, H. Kubo and T. Nagasaka, “Removal of Arsenic in Coal Fly Ash by Acid Washing Process Using Dilute H2SO4 Solvent,” Journal of Hazardous Materials, Vol. 181, No. 1-3, 2010, pp. 419-425. doi:10.1016/j.jhazmat.2010.05.027
[9] S. Kashiwakura, H. Ohno, Y. Kumagai, H. Kubo, K. Matsubae and T. Nagasaka, “Dissolution Behavior of Selenium from Coal Fly Ash Particles for the Development of an Acid-Washing Process,” Chemosphere, Vol. 85, No. 4, 2011, pp. 598-602. doi:10.1016/j.chemosphere.2011.06.099
[10] JOGMEC, “Material Flow of Mineral Resources,” 2010. http://www.jogmec.go.jp/mric_web/jouhou/material/2010/REE.pdf
[11] Z. X. Yuan, C. Y. Wu, L. M. Xu and Y. X. Ni, “The Distribution of Trace Elements in Granitoids in the Nanling Region of China,” Chinese Journal of Geochemistry, Vol. 12, No. 3, 1993, pp. 193-205. doi:10.1007/BF02843359
[12] S. Kashiwakura, T. Takahashi, H. Maekawa and T. Nagasaka, “Application of 11B MAS-NMR to the Characterization of Boron in Coal Fly Ash Generated from Nantun Coal,” Fuel, Vol. 89, No. 5, 2010, pp. 1006-1011. doi:10.1016/j.fuel.2009.10.028
[13] S. Iwata, K. Minamoto, E. Fujimori, K. Chiba and H. Haraguchi, “Determination of Rare Earth Elements in Industrial Waste Incineration Fly Ash by ICP-MS and the Characteristics of the Rare-Earth Element Distribution Pattern (in Japanese),” BUNSEKI KAGAKU, Vol. 50, No. 6, 2001, pp. 419-425. doi:10.2116/bunsekikagaku.50.419
[14] R. R. Greenberg, E. A. Mackey and D. A. Becker, “The Application of Instrumental Neutron Activation Analysis for the Certification of the New NIST Fly Ash SRM,” Journal of Radioanalytical and Nuclear Chemistry, Vol. 193, No. 1, 1995, pp. 7-14. doi:10.1007/BF02041911
[15] I. Roelandts and E. S. Gladney, “Consensus Values for NIST Biological and Environmental Standard Reference Materials,” Fresenius Journal of Analytical Chemistry, Vol. 360, No. 3-4, 1998, pp. 327-338. doi:10.1007/s002160050704
[16] A. Masuda, “Regularities in Variation of Relative Abundances of Lanthanide Elements and an Attempt to Analyse Separation-Index Patterns of Some Minerals,” The Journal of Earth Sciences, Nagoya University, Vol. 10, No. 2, 1962, pp. 173-187.
[17] C. D. Coryell, J. W. Chase and J. W. Winchester, “A Procedure for Geochemical Interpretation of Terrestrial Rare-Earth Abundances Patterns,” Journal of Geophysical Research, Vol. 68, No. 2, 1963, pp. 559-566. doi:10.1029/JZ068i002p00559
[18] K. Fujita and Y. Arikawa, “Determination of Rare Earth Elements in Coal Samples by ICP-MS,” The Bulletin of Japan Women’s University, Vol. 14, 2006, pp. 7-11.
[19] W. McDonough and S. Sun, “The Composition of the Earth,” Chemical Geology, Vol. 130, No. 3-4, 1995, pp. 223-253. doi:10.1016/0009-2541(94)00140-4
[20] R. L. Davison, D. F. S. Natusch, J. R. Wallace and C. Evans Jr, “Trace Elements in Fly Ash. Dependence of Concentration on Particle Size,” Environmental Science & Technology., Vol. 8, No. 13, 1974, pp. 1107-1113. doi:10.1021/es60098a003
[21] K. C. Galbreath, D. L. Toman, C. J. Zygarlicke and J. H. Pavlish, “Trace Element Partitioning and Transformations during Combustion of Bituminous and Subbituminous U. S. Coals in a 7-kW Combustion System,” Energy & Fuel, Vol. 14, No. 6, 2000, pp. 1265-1279. doi:10.1021/ef000105n
[22] R. Meij, “Trace Element Behavior in Coal-Fired Power Plants,” Fuel Processing Technology, Vol. 39, No. 1-3, 1994, pp. 199-217. doi:10.1016/0378-3820(94)90180-5
[23] R. Meij and H. Winkel, “The Emissions of Heavy Metals and Persistent Organic Pollutants from Modern Coal-Fired Power Stations,” Atmospheric Environment, Vol. 41, No. 40, 2007, pp. 9262-9272. doi:10.1016/j.atmosenv.2007.04.042
[24] S. Kashiwakura, T. Takahashi and T. Nagasaka, “Vaporization Behavior of Boron from Standard Coals in the Early Stage of Combustion,” Fuel, Vol. 90, No. 4, 2011, pp. 1408-1415. doi:10.1016/j.fuel.2010.12.029
[25] A. Roine, “Outokumpu HSC Chemistry for Windows, Version 5.1,” 2002.
[26] N. Tsubouchi, Y. Wang and Y. Ohtsuka, “Fate of the Chlorine in Coal during Temperature-Programmed Pyrolysis,” The proceedings of the Japan Institute of Energy, Vol. 40, 2003, pp. 124-125 (in Japanese).
[27] N. Tsubouchi, H. Hayashi and Y. Ohtsuka, “Functional Forms of the Fluorine and Carbon in Fly Ashes Formed in Pulverized Coal Combustion,” The proceedings of the Japan Institute of Energy, Vol. 42, 2005, pp. 59-60 (in Japanese).
[28] S. Yagi and D. Kunii, “Fluidized-Solids Reactors with Continuous Solid Feed—I: Residence Time of Particles in Fluidized Beds,” Chemical Engineering Science, Vol. 16, No. 3-4, 1961, pp. 364-371. doi:10.1016/0009-2509(61)80043-2

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.