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Journals / International Journal of Pure and Applied Sciences / 2026 / Volume: 7 Issue: 2 Special Issue

Acquisition of Rare Earth Elements by Application of Hydrometallurgical Methods

Hidrometalurjik Yöntemlerle Nadir Toprak Elementlerinin Kazanılması

Mehmet Kayra Tanaydın(MUNZUR UNIVERSITY)0000-0003-1696-0754
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Publication Date
2021-07-20
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

With the application of hydrometallurgical processes, processes that may be beneficial for the recovery of rare earth elements under various conditions have been evaluated.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:The demand for rare earth elements in the world is increasing rapidly, but the supply amounts of these elements are decreasing due to export quotas imposed by the Chinese government and illegal mining operations.
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Key Findings & Data:Many countries have accelerated their efforts to obtain rare earth elements from primary and secondary sources in order to meet their future needs by taking measures.
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Conclusion & Impact:With the application of hydrometallurgical processes, processes that may be beneficial for the recovery of rare earth elements under various conditions have been evaluated.
🔬Design:Review
📍Scope:Comprehensive Sample
⚙️Variables:Hydrometallurgy · leaching · solvent extraction

Abstract

The demand for rare earth elements in the world is increasing rapidly, but the supply amounts of these elements are decreasing due to export quotas imposed by the Chinese government and illegal mining operations. Many countries have accelerated their efforts to obtain rare earth elements from primary and secondary sources in order to meet their future needs by taking measures. Rare earth elements are the most important components necessary both for the design and development of high-tech products that we use in our daily lives and for the advancement of modern industry. These elements, which have become indispensable materials of our lives, are generally not found in pure form in nature, but in complex structures in ores. Rare earth elements have close to 250 known minerals, but ores such as bastnasite, monazite and xenotime are commercially exploited. It is usually physically enriched by flotation, gravity, electrostatic or magnetic separation processes to obtain bastnasite, monazite and xenotime concentrates. In order to develop viable and environmentally friendly processes, studies are carried out for the extraction of rare earth elements from leaching solutions (chloride, nitrate, sulfate, thiocyanate, etc.) and the use of different cationic, anionic and neutral extractants depending on the solution medium. Commercial extraction of rare earth elements D2EHPA, Cyanex 272, PC-88A, Versatic 10, TBP, Aliquat 336 etc. carried out using different extractants. In this work, hydrometallurgical methods used for the recovery of rare earth elements from primary sources are examined. These methods are hydrometallurgical methods consisting of leaching with acids and alkalis followed by processes such as solvent extraction, ion exchange or precipitation and reduction. With the application of hydrometallurgical processes, processes that may be beneficial for the recovery of rare earth elements under various conditions have been evaluated.

Özet

Dünya’da nadir toprak elementlerine olan talep hızla artmakta, buna karşın Çin hükümetinin dayattığı ihracat kotaları ve yasadışı madencilik operasyonları nedeniyle bu elementlerin arz miktarları azalmaktadır. Birçok ülke önlemler alarak gelecekteki ihtiyaçlarını karşılamak için nadir toprak elementlerini birincil ve ikincil kaynaklardan kazanmaya yönelik çalışmalarını hızlandırmıştır. Nadir toprak elementleri, hem günlük yaşantımızda kullandığımız yüksek teknoloji ürünlerinin tasarlanması ve geliştirilmesi hem de modern endüstrinin ilerlemesi için gerekli olan en önemli bileşenlerdir. Hayatımızın vazgeçilmez malzemeleri haline gelen bu elementler doğada genellikle saf halde değil, cevherlerde kompleks yapıda bulunurlar. Nadir toprak elementleri 250’ye yakın bilenen minerale sahiptir ancak bunlardan bastnazit, monazit ve ksenotim gibi cevherler ticari olarak işletilmektedir. Bastnazit, monazit ve ksenotim konsantreleri elde etmek için genellikle flotasyon, gravite, elektrostatik veya manyetik ayırma işlemleri ile fiziksel olarak zenginleştirilirler. Uygulanabilir ve çevre dostu prosesler geliştirmek için, nadir toprak elementlerinin liç çözeltilerinden (klorür, nitrat, sülfat, tiyosiyanat, vb. ortamlarda) ekstraksiyonu, çözelti ortamına bağlı olarak farklı katyonik, anyonik ve nötr ekstraktantların kullanılmasına yönelik çalışmalar yürütülmektedir. Nadir toprak elementlerinin ticari ekstraksiyonu D2EHPA, Cyanex 272, PC-88A, Versatic 10, TBP, Aliquat 336 vb. farklı ekstraktantlar kullanılarak gerçekleştirilmektedir. Bu makalede, nadir toprak elementlerinin birincil kaynaklardan kazanılması için kullanılan hidrometalurjik yöntemler incelenmiştir. Bu yöntemler, asitler ve alkaliler ile liç ve ardından solvent ekstraksiyonu, iyon değişimi veya çöktürme ve indirgenme gibi proseslerden oluşan hidrometalurjik yöntemlerdir. Hidrometalurjik proseslerin uygulanmasıyla çeşitli şartlar altında nadir toprak elementlerinin kazanımı için yararlı olabilecek prosesler değerlendirilmiştir.

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Cite This Article

Tanaydın, M. K. (2021). Acquisition of Rare Earth Elements by Application of Hydrometallurgical Methods. International Journal of Pure and Applied Sciences, Volume: 7 Issue: 2 Special Issue. https://doi.org/10.29132/ijpas.908824

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References (72)

  1. Alstad, J., & Brunfelt, A. O. (1967). Adsorption of the rare-earth elements on an anion-exchange resin from nitric acid-acetone mixtures. Analytica Chimica Acta, 38(C), 185–192. https://doi.org/10.1016/S0003-2670(01)80576-6
  2. Arslan Topal, E. I., & Elitok, Z. (2018). Seasonal Monitoring of Cu and Zn in the Sewage Sludge of Malatya Advanced Biological Wastewater Treatment Plant. International Journal of Pure and Applied Sciences, 4(1), 51–60. https://doi.org/10.29132/ijpas.365425
  3. Atanassova, M. (2006). Solvent extraction and separation of lanthanoids with mixtures of chelating extractant and 1-(2-pyridylazo)-2-naphthol. Separation and Purification Technology, 49(1), 101–105. https://doi.org/10.1016/j.seppur.2005.09.001
  4. Atanassova, M., Kurteva, V., Lubenov, L., & Billard, I. (2016). Solvent extraction and separation of light lanthanoids with mixtures of two chelating extractants: Benzene vs. ionic liquid. Separation Science and Technology, 51(2), 290–299. https://doi.org/10.1080/01496395.2015.1088028 Awwad, N. S., Gad, H. M. H., & Aly, H. F. (2008). Extraction of Eu(III) from nitrate medium by CYANEX921 using solvent extraction technique. International Journal of Physical Sciences, 3(1), 22–27. Retrieved from http://www.academicjournals.org/IIJPS
  5. BAKICI TANAYDIN, Z., TANAYDIN, M. K., DEMİRKIRAN, N., & İNCE, M. (2020). Adsorption of Copper and Cadmium with Perlite and Comparison of Adsorption Properties. International Journal of Pure and Applied Sciences, 6(2), 208–218. https://doi.org/10.29132/ijpas.746970
  6. Balaram, V. (2019). Rare earth elements: A review of applications, occurrence, exploration, analysis, recycling, and environmental impact. Geoscience Frontiers, 10(4), 1285–1303. https://doi.org/10.1016/j.gsf.2018.12.005
  7. Bauer, D. J. (1966). Extraction and separation of selected lanthanides with a tertiary amine. In RI 6809 (US Bureau of Mines). Washington.
  8. Blakely, C., Cooter, J., Khaitan, A., Sincer, I., & Williams, R. (2012). Rare {Earth} {Metals} & {China}. Ann Arbor, MI: Gerald R. Ford School of Public Policy., 0–19.
  9. CHANG, H., LI, M., LIU, Z., HU, Y., & ZHANG, F. (2010). Study on separation of rare earth elements in complex system. Journal of Rare Earths, 28(SUPPL. 1), 116–119. https://doi.org/10.1016/S1002-0721(10)60270-0
  10. Chi, R., Zhang, X., Zhu, G., Zhou, Z., Wu, Y., Wang, C., & Yu, F. (2004). Recovery of rare earth from bastnasite by ammonium chloride roasting with fluorine deactivation. Minerals Engineering, 17(9–10), 1037–1043. https://doi.org/10.1016/j.mineng.2004.04.010
  11. Chi, R., Zhu, G., Zhou, Z., & Xu, Z. (2000). A novel process for recovering rare earth from weathered black earth. Metallurgical and Materials Transactions B, 31(1), 191–196. https://doi.org/10.1007/s11663-000-0144-6
  12. Dave, S. R., Kaur, H., & Menon, S. K. (2010). Selective solid-phase extraction of rare earth elements by the chemically modified Amberlite XAD-4 resin with azacrown ether. Reactive and Functional Polymers, 70(9), 692–698. https://doi.org/10.1016/j.reactfunctpolym.2010.05.011
  13. European Commission. (2017). Study on the review of the list of Critical Raw Materials - Critical Raw Materials Factsheets. In European Commission. https://doi.org/10.2873/876644
  14. Golev, A., Scott, M., Erskine, P. D., Ali, S. H., & Ballantyne, G. R. (2014). Rare earths supply chains: Current status, constraints and opportunities. Resources Policy, 41(1), 52–59. https://doi.org/10.1016/j.resourpol.2014.03.004
  15. Gupta, B., Malik, P., & Deep, A. (2003). Solvent extraction and separation of tervalent Lanthanides and Yttrium using Cyanex 923. Solvent Extraction and Ion Exchange, 21(2), 239–258. https://doi.org/10.1081/SEI-120018948
  16. Gupta, C. K. (2003). Chemical Metallurgy. In Chemical Metallurgy. Wiley. https://doi.org/10.1002/3527602003
  17. Guru, P., Reddy, P., Reddy, G. V. S., Raja, L., & Reddy, M. (2011). Solvent Extraction of Lanthanum (III) from Tri-n-Octyl Phospine oxide and Dibenzyl sulphoxide in ammoniumthiocyanate. International Journal of Science and Advanced Technology, 1(3), 2221–8386. Retrieved from https://pdfs.semanticscholar.org/f1c8/f4546f37586338e86f2c08521b83b38de5d2.pdf
  18. Habashi, F. (2013). Extractive metallurgy of rare earths. Canadian Metallurgical Quarterly, 52(3), 224–233. https://doi.org/10.1179/1879139513Y.0000000081
  19. Hidayah, N. N., & Abidin, S. Z. (2017). The evolution of mineral processing in extraction of rare earth elements using solid-liquid extraction over liquid-liquid extraction: A review. Minerals Engineering, 112, 103–113. https://doi.org/10.1016/j.mineng.2017.07.014
  20. Hu, Z., Richter, H., Sparovek, G., & Schnug, E. (2004). Physiological and Biochemical Effects of Rare Earth Elements on Plants and Their Agricultural Significance: A Review. Journal of Plant Nutrition, 27(1), 183–220. https://doi.org/10.1081/PLN-120027555
  21. Ismail, N. A., Aziz, M. A. A., Yunus, M. Y. M., & Hisyam, A. (2019). Selection of extractant in rare earth solvent extraction system: A review. International Journal of Recent Technology and Engineering, 8(1), 728–743. Retrieved from https://www.researchgate.net/profile/Nurul_Ismail36/publication/333479263_Selection_of_Extractant_in_Rare_Earth_Solvent_Extraction_System_A_Review/links/5d5ca3e6299bf1b97cfa1ebd/Selection-of-Extractant-in-Rare-Earth-Solvent-Extraction-System-A-Review.pdf
  22. Jha, M. K., Kumari, A., Panda, R., Rajesh Kumar, J., Yoo, K., & Lee, J. Y. (2016). Review on hydrometallurgical recovery of rare earth metals. Hydrometallurgy, 165, 2–26. https://doi.org/10.1016/j.hydromet.2016.01.035
  23. Jowitt, S. M., Werner, T. T., Weng, Z., & Mudd, G. M. (2018, October 1). Recycling of the rare earth elements. Current Opinion in Green and Sustainable Chemistry, Vol. 13, pp. 1–7. Elsevier B.V. https://doi.org/10.1016/j.cogsc.2018.02.008
  24. Kanazawa, Y., & Kamitani, M. (2006). Rare earth minerals and resources in the world. Journal of Alloys and Compounds, 408–412(412), 1339–1343. https://doi.org/10.1016/j.jallcom.2005.04.033
  25. Kastori, R., Maksimovic, I., Zeremski-Skoric, T., & Putnik-Delic, M. (2010). Rare earth elements: Yttrium and higher plants. Zbornik Matice Srpske Za Prirodne Nauke, (118), 87–98. https://doi.org/10.2298/ZMSPN1018087K
  26. Kim, S. J., Han, W. K., Kang, S. G., Han, M. S., & Cheong, Y. H. (2008). Formation of lanthanum hydroxide and oxide via precipitation. Solid State Phenomena, 135, 23–26. Trans Tech Publications Ltd. https://doi.org/10.4028/www.scientific.net/SSP.135.23
  27. Kogel, J., Trivedi, N., Barker, J., & Krukowski, S. (2006). Industrial minerals & rocks: commodities, markets, and uses. Choice Reviews Online, 44(03), 44-1280-44–1280. https://doi.org/10.5860/choice.44-1280
  28. Krishnamurthy, N., & Gupta, C. K. (2015). Extractive Metallurgy of Rare Earths. In Extractive Metallurgy of Rare Earths, Second Edition. CRC Press. https://doi.org/10.1201/b19055
  29. Kul, M., Topkaya, Y., & Karakaya, İ. (2008). Rare earth double sulfates from pre-concentrated bastnasite. Hydrometallurgy, 93(3–4), 129–135. https://doi.org/10.1016/j.hydromet.2007.11.008
  30. Kumar, J., Thomas, K. G., & Liz-Marzán, L. M. (2016). Nanoscale chirality in metal and semiconductor nanoparticles. Chemical Communications, 52(85), 12555–12569. https://doi.org/10.1039/C6CC05613J
  31. Li, W., Wang, X., Meng, S., Li, D., & Xiong, Y. (2007). Extraction and separation of yttrium from the rare earths with sec-octylphenoxy acetic acid in chloride media. Separation and Purification Technology, 54(2), 164–169. https://doi.org/10.1016/j.seppur.2006.08.029
  32. Lucas, J., Lucas, P., Mercier, T. Le, Rollat, A., Le Mercier, T., Rollat, A., & Davenport, W. (2014). Rare Earths: Science, Technology, Production and Use. In Rare Earths: Science, Technology, Production and Use. Elsevier. https://doi.org/10.1016/C2012-0-02577-X
  33. Lwin Thuza Shwe, Nwe Nwe Soe, K. T. L. (2008). Study on Extraction of ceric oxide from monzite concentrate. International Journal of Material and Metallurgical Engineering, 2(12), 370–372. Retrieved from https://staffsites.sohag-univ.edu.eg/uploads/99/1538863575 - 10.1.1.193.6243.pdf
  34. Lyman, J. W., & Palmer, G. R. (1993). Recycling of Rare Earths and Iron from NdFeB Magnet Scrap. High Temperature Materials and Processes, 11(1–4), 175–188. https://doi.org/10.1515/HTMP.1993.11.1-4.175
  35. Mancheri, N. A., Sprecher, B., Bailey, G., Ge, J., & Tukker, A. (2019). Effect of Chinese policies on rare earth supply chain resilience. Resources, Conservation and Recycling, 142, 101–112. https://doi.org/10.1016/j.resconrec.2018.11.017
  36. McGill, I. (2000). Rare Earth Elements. In Ullmann’s Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA. https://doi.org/10.1002/14356007.a22_607
  37. Migaszewski, Z. M., & Gałuszka, A. (2015). The Characteristics, Occurrence, and Geochemical Behavior of Rare Earth Elements in the Environment: A Review. Critical Reviews in Environmental Science and Technology, 45(5), 429–471. https://doi.org/10.1080/10643389.2013.866622
  38. Nagaphani Kumar, B., Radhika, S., & Ramachandra Reddy, B. (2010). Solid-liquid extraction of heavy rare-earths from phosphoric acid solutions using Tulsion CH-96 and T-PAR resins. Chemical Engineering Journal, 160(1), 138–144. https://doi.org/10.1016/j.cej.2010.03.021
  39. Peelman, S., Sun, Z. H. I., Sietsma, J., & Yang, Y. (2015). Leaching of Rare Earth Elements: Review of Past and Present Technologies. In Rare Earths Industry: Technological, Economic, and Environmental Implications (pp. 319–334). Elsevier Inc. https://doi.org/10.1016/B978-0-12-802328-0.00021-8
  40. Pinto, D. V. B., & Martins, A. (2001). Electrochemical elution of a cation-exchange polymeric resin for yttrium and rare earth recovery using a statistical approach. Hydrometallurgy, 60(1), 99–104. https://doi.org/10.1016/S0304-386X(00)00156-0
  41. Pospiech, B., & Kujawski, W. (2015). Ionic liquids as selective extractants and ion carriers of heavy metal ions from aqueous solutions utilized in extraction and membrane separation. Reviews in Chemical Engineering, 31(2), 179–191. https://doi.org/10.1515/revce-2014-0048
  42. Preston, J. S., & Du Preez, A. C. (1992). Solvent-extraction processes for the separation of the rare-earth metals. Proceedings of International Solvent Extraction Conference, ISEC’90, 883–894. Japan.
  43. Radhika, S., Kumar, B. N., Kantam, M. L., & Reddy, B. R. (2010). Liquid-liquid extraction and separation possibilities of heavy and light rare-earths from phosphoric acid solutions with acidic organophosphorus reagents. Separation and Purification Technology, 75(3), 295–302. https://doi.org/10.1016/j.seppur.2010.08.018
  44. Radhika, S., Nagaphani Kumar, B., Lakshmi Kantam, M., & Ramachandra Reddy, B. (2011). Solvent extraction and separation of rare-earths from phosphoric acid solutions with TOPS 99. Hydrometallurgy, 110(1–4), 50–55. https://doi.org/10.1016/j.hydromet.2011.08.004
  45. Radhika, S., Nagaraju, V., Nagaphani Kumar, B., Kantam, M. L., & Reddy, B. R. (2012). Solid-liquid extraction of Gd(III) and separation possibilities of rare earths from phosphoric acid solutions using Tulsion CH-93 and Tulsion CH-90 resins. Journal of Rare Earths, 30(12), 1270–1275. https://doi.org/10.1016/S1002-0721(12)60219-1
  46. Reddy, A. S., & Reddy, L. K. (1977). Solvent extraction of cerium(III) from ammonium thiocyanate solutions by sulphoxides and their solutions. Journal of Inorganic and Nuclear Chemistry, 39(9), 1683–1687. https://doi.org/10.1016/0022-1902(77)80127-9
  47. Reddy, B. R., Kumar, B. N., & Radhika, S. (2009). Solid-Liquid extraction of terbium from phosphoric acid medium using bifunctional phosphinic acid resin, tulsion CH-96. Solvent Extraction and Ion Exchange, 27(5–6), 695–711. https://doi.org/10.1080/07366290903270031
  48. Reddy, M. L. P., Prasada Rao, T., & Damodaran, A. D. (1993). Liquid-Liquid Extraction Processes for the Separation and Purification of Rare Earths. Mineral Processing and Extractive Metallurgy Review, 12(2–4), 91–113. https://doi.org/10.1080/08827509508935254
  49. Rout, A., & Binnemans, K. (2014). Liquid–liquid extraction of europium(iii) and other trivalent rare-earth ions using a non-fluorinated functionalized ionic liquid. Dalton Trans., 43(4), 1862–1872. https://doi.org/10.1039/C3DT52285G
  50. Sarangi, K., Reddy, B. R., & Das, R. P. (1999). Extraction studies of cobalt (II) and nickel (II) from chloride solutions using Na-Cyanex 272. Hydrometallurgy, 52(3), 253–265. https://doi.org/10.1016/S0304-386X(99)00025-0
  51. Sato, T. (1989). Liquid-liquid extraction of rare-earth elements from aqueous acid solutions by acid organophosphorus compounds. Hydrometallurgy, 22(1–2), 121–140. https://doi.org/10.1016/0304-386X(89)90045-5
  52. Schijf, J., & Byrne, R. H. (1999). Determination of stability constants for the mono- and difluoro-complexes of Y and the REE, using a cation-exchange resin and ICP-MS. Polyhedron, 18(22), 2839–2844. https://doi.org/10.1016/S0277-5387(99)00205-3
  53. Shariati, S., & Yamini, Y. (2006). Cloud point extraction and simultaneous determination of zirconium and hafnium using ICP-OES. Journal of Colloid and Interface Science, 298(1), 419–425. https://doi.org/10.1016/j.jcis.2005.12.005
  54. SHIMOJO, K., NAKAI, A., OKAMURA, H., OHASHI, A., & NAGANAWA, H. (2013). Extraction Behavior and Selective Separation of Lead(II) Using N,N-Dioctyldiglycol Amic Acid. Analytical Sciences, 29(1), 147–150. https://doi.org/10.2116/analsci.29.147
  55. Singh, D. K., Singh, H., & Mathur, J. N. (2006). Extraction of rare earths and yttrium with high molecular weight carboxylic acids. Hydrometallurgy, 81(3–4), 174–181. https://doi.org/10.1016/j.hydromet.2005.12.002
  56. Sun, X., Ji, Y., Guo, L., Chen, J., & Li, D. (2011). A novel ammonium ionic liquid based extraction strategy for separating scandium from yttrium and lanthanides. Separation and Purification Technology, 81(1), 25–30. https://doi.org/10.1016/j.seppur.2011.06.034
  57. Sun, X., Luo, H., & Dai, S. (2012). Solvent extraction of rare-earth ions based on functionalized ionic liquids. Talanta, 90, 132–137. https://doi.org/10.1016/j.talanta.2011.12.069
  58. THAKUR, N. V. (2000). Separation of Rare Earths by Solvent Extraction. Mineral Processing and Extractive Metallurgy Review, 21(1–5), 277–306. https://doi.org/10.1080/08827500008914171
  59. Voncken, J. H. L. (2016a). Physical and Chemical Properties of the Rare Earths. Springer, Cham. https://doi.org/10.1007/978-3-319-26809-5_3
  60. Voncken, J. H. L. (2016b). The Rare Earth Elements. Cham: Springer International Publishing. https://doi.org/10.1007/978-3-319-26809-5
  61. W. D. Jamrack. (1964). Rare metal extraction by chemical engineering techniques. Oxford: Pergamon Press. https://doi.org/10.1016/0009-2509(64)85019-3
  62. Wang, L., Huang, X., Yu, Y., & Long, Z. (2014). Kinetics of rare earth pre-loading with 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester [HEH(EHP)] using rare earth carbonates. Separation and Purification Technology, 122, 490–494. https://doi.org/10.1016/j.seppur.2013.12.007
  63. Waseda, Y., & Isshiki, M. (2002). Purification Process and Characterization of Ultra High Purity Metals. In Purification Process and Characterization of Ultra High Purity Metals. https://doi.org/10.1007/978-3-642-56255-6
  64. Xie, F., Zhang, T. A., Dreisinger, D., & Doyle, F. (2014). A critical review on solvent extraction of rare earths from aqueous solutions. Minerals Engineering, 56, 10–28. https://doi.org/10.1016/j.mineng.2013.10.021
  65. XIONG, C., MENG, Y., YAO, C., & SHEN, C. (2009). Adsorption of erbium(III) on D113-III resin from aqueous solutions: batch and column studies. Journal of Rare Earths, 27(6), 923–931. https://doi.org/10.1016/S1002-0721(08)60364-6
  66. Xiong, C., Zhu, J., Shen, C., & Chen, Q. (2012). Adsorption and desorption of praseodymium (III) from aqueous solution using D72 resin. Chinese Journal of Chemical Engineering, 20(5), 823–830. https://doi.org/10.1016/S1004-9541(12)60405-4 Yao, C. (2010). Adsorption and desorption properties of D151 resin for Ce(III). Journal of Rare Earths, 28(SUPPL. 1), 183–188. https://doi.org/10.1016/S1002-0721(10)60324-9
  67. Yörükoğlu, A., Obut, A., & Girgin, İ. (2003). Effect of thiourea on sulphuric acid leaching of bastnaesite. Hydrometallurgy, 68(1–3), 195–202. https://doi.org/10.1016/S0304-386X(02)00199-8
  68. Zhang, J., & Edwards, C. (2013). Mineral decomposition and leaching processes for treating rare earth ore concentrates. Canadian Metallurgical Quarterly, 52(3), 243–248. https://doi.org/10.1179/1879139513Y.0000000084
  69. Zheng, D., Gray, N. B., & Stevens, G. W. (1991). Comparison of naphthenic acid, versatic acid and d2ehpa for the separation of rare earths. Solvent Extraction and Ion Exchange, 9(1), 85–102. https://doi.org/10.1080/07366299108918044
  70. Zhu, L., & Chen, J. (2011). Adsorption of Ce(IV) in nitric acid medium by imidazolium anion exchange resin. Journal of Rare Earths, 29(10), 969–973. https://doi.org/10.1016/S1002-0721(10)60580-7
  71. Chi, R., Zhang, X., Zhu, G., Zhou, Z., Wu, Y., Wang, C., & Yu, F. (2004). Recovery of rare earth from bastnasite by ammonium chloride roasting with fluorine deactivation. Minerals Engineering, 17(9–10), 1037–1043. https://doi.org/10.1016/j.mineng.2004.04.010
  72. Pinto, D. V. B., & Martins, A. (2001). Electrochemical elution of a cation-exchange polymeric resin for yttrium and rare earth recovery using a statistical approach. Hydrometallurgy, 60(1), 99–104. https://doi.org/10.1016/S0304-386X(00)00156-0