Ultra-selective ion sieve for thorium recovery from rare earth elements using oxygen-rich microporous carbon adsorption

Yangyang Gao; Lihong Xu; Meng Zhang; Qian Zhang; Zhencong Yang; Jialun Yang; Zhanglian Xu; Ying Lv; Yin Wang

doi:10.1016/j.jhazmat.2021.126115

Ultra-selective ion sieve for thorium recovery from rare earth elements using oxygen-rich microporous carbon adsorption

J Hazard Mater. 2021 Sep 5:417:126115. doi: 10.1016/j.jhazmat.2021.126115. Epub 2021 May 15.

Authors

Yangyang Gao¹, Lihong Xu¹, Meng Zhang¹, Qian Zhang¹, Zhencong Yang¹, Jialun Yang¹, Zhanglian Xu², Ying Lv³, Yin Wang⁴

Affiliations

¹ Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology, and Shaanxi Engineering Research Center of Advanced Nuclear Energy, School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, PR China.
² Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology, and Shaanxi Engineering Research Center of Advanced Nuclear Energy, School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, PR China. Electronic address: xuzhanglian@xjtu.edu.cn.
³ College of Materials Science and Engineering, Xi'an Shiyou University, No. 18, 2nd East Dianzi Road, Xi'an, Shaanxi 710065, PR China. Electronic address: 180305@xsyu.edu.cn.
⁴ Department of Chemistry and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, United States; School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, PR China. Electronic address: yinwang@sjtu.edu.cn.

PMID: 34020349
DOI: 10.1016/j.jhazmat.2021.126115

Abstract

The ultra-selective extraction of thorium ions (Th(IV)) from lanthanides is of significance to both solve the radioactive pollution issue in rare earth (RE) production and sustainably provide thorium fuel for the liquid fluoride thorium reactors (LFTR). However, it remains a great challenge. Here, we reported an oxygen-rich microporous carbon for ultra-selective extraction of Th(IV) from rare earth elements (REEs) in a wide pH range. This selectivity was derived from the synergy of the oxygen-rich nature, microporous structure of the carbons, the chemical valence, and the ionic size of Th(IV) species. This oxygen-rich microporous carbon presented an ultra-high distribution coefficient (K_d) of 1.15 × 10⁸ mL g^-1 for Th(IV) at pH 4.9 in the presence of 15 REEs and revealed outstanding performance for Th(IV) extraction from three simulated RE solutions with high ionic strength of lanthanides. Meanwhile, an exceptional adsorption capacity of 624.98 mg g^-1 was obtained in the single Th(IV) solution. Both values were superior to those of reported adsorbents. More importantly, the new adsorbent developed here could be prepared from cigarette butts. These features ensured the oxygen-rich carbon as a promising and cost-effective adsorbent for high-purity thorium extraction from REEs.

Keywords: Adsorption; Oxygen-rich microporous carbon; Rare earth elements; Selectivity; Thorium.