Solvent Extraction of Lanthanum Ion from Chloride Medium by Di-(2-ethylhexyl) Phosphoric Acid with a Complexing Method

Shaohua Yin, Wenyuan Wu, Xue Bian, Yao Luo, Fengyun Zhang

School of Materials and Metallurgy, Northeastern University, Shenyang, China.

DOI: 10.4236/ijnm.2013.22010                

Abstract

Solvent extraction experiments of La(III) with di-(2-ethylhexyl)phosphoric acid (P204) from chloride solution in the presence of a complexing agent (lactic acid) have been performed. The effective separation factors can be achieved when the complexing agent is added to the aqueous phase of the extraction system. The complexing agent lactic acid can be effectively recycled using tributyl phosphate (TBP) as extractant, by the use of a countercurrent extraction process, and the chemical oxygen demand (COD) value in the raffinate is 57.7 mg/L, which meets the emission standards of pollutants from rare earths industry. Thus, the simple and environment-friendly complexing method has been proved to be an effective strategy for separating light rare earths, and provides a positive influence on the purification of La(III).

Keywords

La(III); Extraction and Separation; P204 Extractant; Lactic Acid; TBP

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	D. H. Cheng, X. W. Chen, Y. Shu and J. H. Wang, “Se lective Extraction/Isolation of Hemoglobin with Ionic Liquid 1-Butyl-3-trimethylsilylimidazolium Hexa?uoro phosphate (BtmsimPF6),” Talanta, Vol. 75, No. 5, 2008, pp. 1270-1278. doi:10.1016/j.talanta.2008.01.044
[2]	X. W. Huang, H. W. Li, X. X. Xue and G. C. Zhang, “Development Status and Research Progress in Rare Earth Hydrometallurgy in China,” Journal of the Chinese Rare Earth Society, Vol. 24, No. 2, 2006, pp. 129-133.
[3]	Z. G. Zhu and J. G. Cheng, “The Research on Waste Wa ter’s Processing Method by Rare Earth Hydrometal lurgy,” China’s Manganese Industy, Vol. 28, No. 3, 2010, pp. 34-36.
[4]	Z. F. Zhang, H. F. Li, F. Q. Guo, S. L. Meng and D. Q. Li, “Synergistic Extraction and Recovery of Cerium(IV) and Fluorin from Sulfuric Solutions with Cyanex 923 and Di-2-ethylhexyl Phosphoric Acid,” Separation and Purification Technology, Vol. 63, No. 2, 2008, pp. 348-352. doi:10.1016/j.seppur.2008.05.023
[5]	N. Z. Song, S. S. Tong, W. Liu, Q. Jia, W. H. Zhou and W. P. Liao, “Extraction and Separation of Rare Earths from Chloride Medium with Mixtures of 2-Ethylhexyl phosphonic Acid Mono-(2-ethylhexyl) Ester and Sec Nonylphenoxy Acetic Acid,” Journal of Chemical Technology and Biotechnology, Vol. 63, No. 12, 2009, pp. 1798-1802. doi:10.1002/jctb.2248
[6]	X. H. Luo, X. W. Huang, Z. W. Zhu, Z. Q. Long and Y. J. Liu, “Synergistic Extraction of Cerium From Sulfuric Acid Medium Using Mixture of 2-Ethylhexyl Phosphonic Acid Mono 2-Ethylhexyl Ester and Di-(2-ethyl hexyl) Phosphoric Acid as Extractant,” Journal Rare Earths, Vol. 27, No. 1, 2009, pp. 119-122. doi:10.1016/S1002-0721(08)60204-5
[7]	X. Q. Sun, Y. Ji, F. C. Hu, B. He, J. Chen and D. Q. Li, “The Inner Synergistic Effect of Bifunctional Ionic Liquid Extractant for Solvent Extraction,” Talanta, Vol. 81, No. 4-5, 2010, pp. 1877-1883. doi:10.1016/j.talanta.2010.03.041
[8]	V. M. Egorov, D. I. Djigailo, D. S. Momotenko, D. V. Chernyshov, I. I. Torocheshnikova, S. V. Smirnova and I. V. Pletnev, “Task-Specific Ionic Liquid Trioctylmethyl ammonium Salicylate as Extraction Solvent for Transition Metal Ions,” Talanta, Vol. 80, No. 3, 2010, pp. 1177-1182. doi:10.1016/j.talanta.2009.09.003
[9]	W. Wang, H. L.Yang, H. M. Cui, D. L. Zhang, Y. Liu and J. Chen, “Application of Bifunctional Ionic Liquid Extractants [A336][CA-12] and [A336][CA-100] to the Lanthanum Extraction and Separation from Rare Earths in the Chloride Medium,” Industrial and Engineering Chemistry Research, Vol. 50, No. 12, 2011, pp. 7534-7541. doi:10.1021/ie2001633
[10]	X. B. Sun, Y. G. Wang and D. Q. Li, “Selective Separation of Yttrium by CA-100 in the Presence of a Complexing Agent,” Rare Earths 2004 Conference, Nara, 7-12 November 2004, pp. 999-1002.
[11]	S. Sujatha, M. L. P. Reddy, T. R. Ramamohan and A. D. Damodaran, “Effect of Water Soluble Complexing Agent on the Extraction of Ce(III) and Nd(III) by 2-Ethyl hexylphosphonic Acid Mono-2-ethylhexyl Ester,” Journal of Radioanalytical and Nuclear Chemistry, Vol. 174, No. 2, 1993, pp. 271-278. doi:10.1007/BF02037914
[12]	S. Nishihama, T. Hirai and I. Komasawa, “Advanced Liquid-Liquid Extraction Systems for the Separation of Rare Earth Ions by Combination of Conversion of the Metal Species with Chemical Reaction,” Journal of Solid State Chemistry, Vol. 171, No. 1-2, 2003, pp. 101-108. doi:10.1016/S0022-4596(02)00198-6
[13]	S. Nishihama, T. Hirai and I. Komasawa, “Selective Ex traction of Y from a Ho/Y/Er Mixture by Liquid-Liquid Extraction in the Presence of a Water-Soluble Complexing Agent,” Industrial and Engineering Chemistry Research, Vol. 39, No. 10, 2000, pp. 3907-3911. doi:10.1021/ie000030a
[14]	Y. G. Wang, Y. Xiong, S. L. Meng and D. Q. Li, “Separation of Yttrium from Heavy Lanthanide by CA-100 Using the Complexing Agent,” Talanta, Vol. 63, No. 2, 2004, pp. 239-243. doi:10.1016/j.talanta.2003.09.034
[15]	S. Nishihama, T. Hirai and I. Komasawa, “Review of Ad vanced Liquid Liquid Extraction Systems for the Separation of Metal Ions by a Combination of Conversion of the Metal Species with Chemical Reaction,” Industrial and Engineering Chemistry Research, Vol. 40, No. 14, 2001, pp. 3085-3091. doi:10.1021/ie010022+
[16]	X. Q. Sun, B. Peng, J. Chen, D. Q. Li and F. Luo, “An Effective Method for Enhancing Metal-Ions’ Selectivity of Ionic Liquid-Based Extraction System: Adding Water Soluble Complexing Agent,” Talanta, Vol. 74, No. 4, 2008, pp. 1071-1074. doi:10.1016/j.talanta.2007.07.031
[17]	H. T. Chang, W. Y. Wu, G. F. Tu, Y. H. Zhao, D. Li and X. Y. Sang, “Extraction of Light Rare Earth in the System of P204-HCl-H3cit,” Chinese Rare Earths, Vol. 28, No. 3, 2008, pp. 18-21.
[18]	S. H. Yin, W. Y. Wu, X. Bian and F. Y. Zhang, “Effect of Complexing Agent Lactic Acid on the Extraction and Separation of Pr(III)/Ce(III) with Di-(2-ethylhexyl) Phosphoric Acid,” Hydrometallurgy, Vol. 131-132, 2013, pp. 133-137. doi:10.1016/j.hydromet.2012.11.005
[19]	N. V. Thakur, D. V. Jayawant, N. S. Iyer and K. S. Kop piker, “Separation of Neodymium from Lighter Rare Earths Using Alkyl Phosphonic Acid, PC88A,” Hydro metallurgy, Vol. 34, No. 1, 1993, pp. 99-108. doi:10.1016/0304-386X(93)90084-Q
[20]	X. K. Wu and Q. P. Jin, “Treatment Technology of Organic Wastewater,” East China Institute of Chemical Press, Shanghai, 1989.