Current Research Trends for Recovery of Rare Earth Elements Contained in Coal Ash

Young-Jin Kim; Moon-Kwan Choi; Jun-Hyung Seo; Byung-Ryeol Kim; Kye-Hong Cho

doi:10.7844/kirr.2020.29.6.3

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2020 Vol.29, Issue 6 Next Page

Article Review

Current Research Trends for Recovery of Rare Earth Elements Contained in Coal Ash 석탄재에 포함된 희토류 회수 연구동향

31 December 2020. pp. 3-14

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Abstract

This study aims to introduce and review on the recovery technologies of rare earth elements(REEs) from coal ash. Many researchers have been carried out by various beneficiation processes, such as particle size separation, magnetic separation, specific gravity, and flotation to recover rare earth elements from coal ash generated from Pulverized Coal(PC) boiler. Through the beneficiation process, it was confirmed that concentration of rare earth elements was much lower than the 4,700 ppm, and that additional enrichment treatment through wet process was needed for the products recovered after the beneficiation process. It was confirmed that the rare earth elements contained in coal ash were applied to the leaching process after pretreatment such as alkali-fusion to improve leaching efficiency. Although beneficiation and leaching methods have been studied, its optimum recovery technologies for rare earth elements not been confirmed up to now, research on the recovery of rare earth contained in coal ash is reported to continue. In case of Korea, the technology for the recovery of rare earth elements from coal ash and coal by-product could not been confirmed up to present. In these reasons, it is urgent to develop technologies such as beneficiation and leaching process continuously.

Keywords

Coal ash

Rare earth elements

Recovery

Beneficiation

Leaching

석탄재로부터 희토류 회수에 관한 연구 자료를 분석 및 검토하였다. 석탄재로부터 희토류 회수를 위해 적용된 선별 실험은 주로 PC 보일러로부터 발생된 석탄재를 대상으로 입도분리, 자력, 비중 및 부유선별법 등을 이용해 연구하였다. 선별 공정을 통해 희토류 성분의 농축 가능한 수준은 수 천 ppm 정도로 낮게 확인되었고, 선별 공정 이후 회수된 산물을 대상으로 습식 제련 공정을 통한 추가 농축 처리가 필요한 것으로 확인되었다. 침출 공정에서는 석탄재의 희토류 성분을 침출 향상을 위해 알칼리 용융과 같은 전처리 후, 침출공정에 적용하는 것이 효율적인 공정으로 확인되었다. 세계적 희토류 회수 시스템의 개발이 아직은 미흡한 것으로 확인되었으나, 석탄재에 포함된 희토류 회수 연구는 계속 진행될 것으로 보고되었다. 국내에서는 석탄재 중 희토류 회수를 위한 회수 기술이 매우 부족한 상황으로 선별, 침출 등의 기술 개발이 시급한 실정이다.

키워드

석탄재

희토류

회수

선별

침출

References

Dushyantha, N., Batapola, N., Ilankoon, I. M. S. K., et al., 2020 : The story of rare earth elements(REEs): Occurrences, global distribution, genesis, geology, mineralogy and global production, Ore Geology Reviews, 122, pp.1-17. 10.1016/j.oregeorev.2020.103521

Zhou, B., Li, Z., Chen, C., 2017 : Global potential of rare earth resources and rare earth demand from clean technologies, Minerals, 7(11), 203. 10.3390/min7110203

https://www.posri.re.kr/ko/board/content/15958

Taggart, R. K., Hower, J. C., Dwyer, G. S., et al., 2016 : Trends in the Rare Earth Element Content of U.S.- Based Coal Combustion Fly Ashes, Environ. Sci. Technol., 50, pp.5919-5926. 10.1021/acs.est.6b0008527228215

Zhang, W., Yang, X., Honaker, R. Q., 2018 : Association characteristics study and preliminary recovery investigation of rare earth elements from fire clay seam coal middlings, Fuel, 215, pp.551-560. 10.1016/j.fuel.2017.11.075

Honaker, R. Q., Zhang, W., Werner, J., 2019 : Acid leaching of rare earth elements from coal and coal ash: implications for using fluidized bed combustion to assist in the recovery of critical materials, Energy and Fuel, 33, pp.5971-5980. 10.1021/acs.energyfuels.9b00295

Middleton, A., Park, D. M., Jiao, Y., et al., 2020 : Major element composition controls rare earth element solubility during leaching of coal fly ash and coal by-product, International Journal of Coal Geology, 227, pp.1-8. 10.1016/j.coal.2020.103532

Pan, J., Nie, T., Hassas, B. V., et al., 2020 : Recovery of rare earth elements from coal fly ash by integrated physical separation and acid leaching, Chemosphere, 248, pp.129-139. 10.1016/j.chemosphere.2020.12611232069698

Lanzerstorfe, C., 2018 : Pre-processing of coal combustion fly ash by classification for enrichment of rare earth elements, Energy Reports, 4, pp.660-663. 10.1016/j.egyr.2018.10.010

Lin, R., Stuckman, M., Howard, B. H., et al., 2016 : Application of sequential extraction and hydrothermal treatment for characterization and enrichment of rare earth elements from coal fly ash, Fuel, 232, pp.124-133. 10.1016/j.fuel.2018.05.141

Blissett, R. S., Smalley, N., Rowson, N. A., et al., 2014 : An investigation into six coal fly ashes from the United Kingdom and Poland to evaluate rare earth element content, Fuel, 119, pp.236-239. 10.1016/j.fuel.2013.11.053

Tang, M., Zhou, C., Pan, J., et al., 2019 : Study on extraction of rare earth elements from coal fly ash through alkali fusion-acid, Minerals Engineering, 136, pp.36-42. 10.1016/j.mineng.2019.01.027

Rosita, W., Bendiyasa, I. M., Perdana, I., et al., 2020 : Sequential particle-size and magnetic separation for enrichment of rare earth elements and yttrium in Indonesia coal fly ash, Journal of Environmental Chemical Engineering, 8, pp.1-10. 10.1016/j.jece.2019.103575

Kim, Y. J., Kim, S. H., and Lee, J. R., 2019 : Economic evaluation of rare earth elements contained in coal ash, J. of Kore Inst. of Resources Recycling, 28(6), pp.26-35.

Moore, F., and Esmaeili, Ali., 2012 : Mineralogy and geochemistry of the coals from the Karmozd and Kiasar coal mines, International Journal of Coal Geology, 96-97, pp.9-21. 10.1016/j.coal.2012.02.012

Folgueras, M. B., Alonso, M., Fernández, F. J., 2017 : Coal and sewage sludge ashes as sources of rare earth elements, Fuel, 192, pp.128-139. 10.1016/j.fuel.2016.12.019

Kolker, A., Scott, C., Hower, J. C., et al., 2017 : Distribution of rare earth elements in coal combustion fly ash, determined by SHRIMP-RG ion microprobe, International Journal of Coal Geology, 184, pp.1-10. 10.1016/j.coal.2017.10.002

Yang, J., Zhao, Y., Zyryanov, V., et al., 2014 : Physical- chemical characteristics and elements enrichment of magnetospheres from coal fly ashes, Fuel, 135, pp.15-26. 10.1016/j.fuel.2014.06.033

Zeng, T., Helble, J. J., Bool, L. E., et al., 2009 : Iron transformations during combustion of Pittsburgh no. 8 coal, Fuel, 88, pp.566-572. 10.1016/j.fuel.2008.11.007

Hower, J., Groppo, J., Joshi, P., et al., 2013 : Location of cerium in coal-combustion fly ashes: implications for recovery of lanthanide, Coal Combustion and Gasfication Products, 3, pp.73-78. 10.4177/CCGP-D13-00007.1

Dai, S., Zhao, L., Hower, J. C., et al., 2014 : Petrology, mineralogy, and chemistry of size-fractioned fly ash from the Jungar power plant, inner Mongolia, China, with emphasis in the distribution of rare earth elements, Energy and Fuel, 28, pp.1502-1514. 10.1021/ef402184t

Pan, J., Zhou, C., Tang, M., et al., 2019 : Study on the modes occurrence of rare earth elements in coal fly ash by statics and and a sequential chemical extraction procedure, Fuel, 237, pp.555-565. 10.1016/j.fuel.2018.09.139

Seredin, V. V., 2010 : A new method for primary evaluation of the outlook for rare earth element ores, Geology of Ore Deposits, 52(5), pp.428-433. 10.1134/S1075701510050077

Ketris, M. P., Yudovich Y. E., 2009 : Estimations of clarkes for carbonaceous biolithes: world averages for trace element contents in black shales and coals, International Journal of Coal Geology, 78, pp.135-148. 10.1016/j.coal.2009.01.002

Perämäki, S. E., Tiihonen, A. J., Väisänen, A. O., 2019 : Occurence and recovery potential of rare earth elements in finish peat and biomass combustion fly ash, Journal of Geochemical Exploration, 201, pp.71-78. 10.1016/j.gexplo.2019.03.002

Dai, S., Graham, I, T., Ward, C. R., 2016 : A review of anomalous rare earth elements and yttrium in coal, International Journal of Coal Geology, 159, pp.82-95. 10.1016/j.coal.2016.04.005

Adamczyk, Z., Komorek, J., Białecka, B., et al., 2020 : Assessment of the potential of polish fly ashes as source of rare earth elements, Ore geology review, 124, pp.1-17. 10.1016/j.oregeorev.2020.103638

Serendin, V. V., Dai, S., 2012 : Coal deposits as potential alternative sources for lanthanides and yttrium, International Journal of Coal Geology, 94, pp.67-93. 10.1016/j.coal.2011.11.001

Lin, R., Howard, B. H., Roth, E. A., 2017 : Enrichment of rare earth elements from coal and coal by-products by physical separations, Fuel, 200, pp.506-520 10.1016/j.fuel.2017.03.096

Zang, W., Honaker, R., Groppo, J., 2017 : Concentration of rare earth minerals from coal by froth flotation, Minerals and Metallurgical Processing, 34(3), pp. 132-137. 10.19150/mmp.7613

Jordens, A., Cheng, Y. P., Waters, K. E., 2013 : A review of the beneficiation of rare earth element bearing minerals, Mineral Engineering, 41, pp.97-114. 10.1016/j.mineng.2012.10.017

Dai, S., Finkelman, R. B., 2018 : Coal as a promising source of critical elements: progress and future prospects, International Journal of Coal Geology, 186, pp.155-164. 10.1016/j.coal.2017.06.005

Ponou, J., Dodbiba, G., Ahn, J. W., et al., 2016 : Selective recovery of rare earth elements from aqueous solution obtained from coal power plant ash, Journal of Environmental Chemical Engineering, 4, pp.3761-3766. 10.1016/j.jece.2016.08.019

Tuan, L. Q., Thenepalli, T., Ramakrishana, C., et al., 2019 : Leaching characteristics of low concentration rare earth elements in Korean (Samcheok) CFBC bottom ash samples, Sustainability, 11(9), pp.25-62. 10.3390/su11092562

Taggart, R. K., Hower, J. C., and Hsu-Kim, H., 2018 : Effects of roasting additives and leaching parameters on the extraction of rare earth elements from coal fly ash, International Journal of Coal Geology, 196(1), pp.106-114. 10.1016/j.coal.2018.06.021

King, J. F., Taggart, R. K., Smith, R. C., et al., 2018 : Aqueous acid and alkaline extraction of rare earth elements from coal combustion ash, International Journal of Coal Geology, 195, pp.75-83. 10.1016/j.coal.2018.05.009

Information

Publisher :The Korean Institute of Resources Recycling
Publisher(Ko) :한국자원리싸이클링학회
Journal Title :Journal of the Korean Institute of Resources Recycling
Journal Title(Ko) :자원리싸이클링
Volume : 29
No :6
Pages :3-14
Received Date : 2020-11-18
Revised Date : 2020-12-02
Accepted Date : 2020-12-09
DOI :https://doi.org/10.7844/kirr.2020.29.6.3

Resources Recycling ISSN:2765-3439(Print) 2765-3447(Online) 자원리싸이클링

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