Scandium recovery from ion-adsorption rare earth concentrate with HEHEHP as extractant

Abstract

An excellent extraction selectivity towards Sc over other REEs in 4 mol/L HCl solution was achieved with the separation factor β_Sc/REEs over 8000 by 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester (HEHEHP) and the extraction equilibrium can be obtained within 20 min. The extracted Sc can be stripped using 5 mol/L NaOH solution as eluent at 363 K with the stripping rate of 92.1% obtained. The extraction mechanism was clearly elucidated by slope analysis, saturation extraction, IR, and NMR analysis. It was revealed that the extraction of Sc in 4 mol/L HCl solution is still dominated by cation exchange process between P—O—H and Sc, and coordination process between P=O and Sc, with 6 molecules of extractant as dimer participating in the process. Finally, a flowsheet for the recovery of Sc from ion-adsorption rare earth elements (REEs) concentrate was proposed and proved in lab-scale experiment.

Keywords

scandium / HEHEHP / solvent extraction / ion-adsorption rare earth

References

[1] CuiH-m, ChenJ, LiH-l, ZouD, LiuY, DengY-feng. High-performance polymer-supported extractants with phosphonate ligands for scandium(III) separation [J]. AlChE J, 2016, 62(7): 2479-2489

[2] HernandezR, ValdovinosH F, YangY-n, ChakravartyR, HongH, BarnhartT E, CaiW-bo. ⁴⁴Sc: An attractive isotope for peptide-based PET imaging [J]. Mol Pharm, 2014, 11(8): 2954-2961

[3] ZhangW, NingS-y, ZhangS-c, WangS-y, ZhouJ, WangX-p, WeiY-zhou. Synthesis of functional silica composite resin for the selective separation of zirconium from scandium [J]. Microporous Mesoporous Mater, 2019, 288: 109602

[4] ZhangW, YuS-q, ZhangS-c, ZhouJ, NingS-y, WangX-p, WeiY-zhou. Separation of scandium from the other rare earth elements with a novel macro-porous silica-polymer based adsorbent HDEHP/SiO₂-P [J]. Hydrometallurgy, 2019, 185117-124

[5] YuQ, NingS-y, ZhangW, WangX-p, WeiY-zhou. Recovery of scandium from sulfuric acid solution with a macro porous TRPO/SiO₂-P adsorbent [J]. Hydrometallurgy, 2018, 181: 74-81

[6] GiretS, HuY-m, MasoumifardN, BoulangerJ F, EstelleJ, KleitzF, LariviereD. Selective separation and preconcentration of scandium with mesoporous silica [J]. ACS Appl Mater Interfaces, 2018, 10(1): 448-457

[7] ZhangN, LiH-x, LiuX-ming. Recovery of scandium from bauxite residue-red mud: A review [J]. Rare Met, 2016, 35(12): 887-900

[8] ZhangX-k, ZhouK-g, ChenW, LeiQ-y, HuangY, PengC-hong. Recovery of iron and rare earth elements from red mud through an acid leaching-stepwise extraction approach [J]. J Cent South Univ, 2019, 26(2): 458-466

[9] PengZ, LiQ-g, LiZ-y, ZhangG-q, CaoZ-y, GuanW-juan. Removal of impurities from scandium solutions by ion exchange [J]. J Cent South Univ, 2018, 25(12): 2953-2961

[10] YangX-j, LinA-j, LiX-l, WuY-d, ZhouW-b, ChenZ-heng. China’s ion-adsorption rare earth resources, mining consequences and preservation [J]. Environ Dev, 2013, 8: 131-136

[11] WangY-l, GuoX-g, BiY-f, SuJ, KongW-c, SunX-qi. Enrichment of trace rare earth elements from the leaching liquor of ion-absorption minerals using a solid complex centrifugal separation process [J]. Green Chem, 2018, 20(9): 1998-2006

[12] WuD-b, NiuC-j, LiD-q, BaiYan. Solvent extraction of scandium(III), yttrium(III), lanthanum(III) and gadolinium(III) using Cyanex 302 in heptane from hydrochloric acid solutions [J]. J Alloys Compd, 2004, 374(1): 442-446 2

[13] WangW-w, ChengC-yong. Separation and purification of scandium by solvent extraction and related technologies: A review [J]. J Chem Technol Biotechnol, 2011, 86(10): 1237-1246

[14] DasS, BeheraS S, MurmuB M, MohapatraR K, MandalD, SamantrayR, ParhiP K, SenanayakeG. Extraction of scandium(III) from acidic solutions using organo-phosphoric acid reagents: A comparative study [J]. Sep Purif Technol, 2018, 202: 248-258

[15] WangC, LiD-qian. Solvent extraction of Sc(III), Zr(lV), Th(IV), Fe(lll), and Lu(lll) with thiosubstituted organophosphinic acid extractants [J]. Solvent Extr Ion Exch, 1995, 13(3): 503-523

[16] WangW-w, PranoloY, ChengC-yong. Recovery of scandium from synthetic red mud leach solutions by solvent extraction with D2EHPA [J]. Sep Purif Technol, 2013, 108: 96-102

[17] ZhouJ, YuQ, HuangY, MengJ-j, ChenY-d, NingS-y, WangX-p, WeiY-z, YinX-b, LiangJie. Recovery of scandium from white waste acid generated from the titanium sulphate process using solvent extraction with TRPO [J]. Hydrometallurgy, 2020, 195: 105398

[18] ZhouJ, NingS-y, MengJ-j, ZhangS-c, ZhangW, WangS-y, ChenY-d, WangX-p, WeiY-zhou. Purification of scandium from concentrate generated from titanium pigments production waste [J]. J Rare Earths, 2021, 39(2): 194-200

[19] WangL-s, HuangX-w, YuY, XiaoY-f, LongZ-q, CuiD-li. Eliminating ammonia emissions during rare earth separation through control of equilibrium acidity in a HEH(EHP)-Cl system [J]. Green Chem, 2013, 15(7): 1889-1894

[20] LiuC-y, ChenL, ChenJ, ZouD, DengY-f, LiD-qian. Application of P507 and isooctanol extraction system in recovery of scandium from simulated red mud leach solution [J]. J Rare Earths, 2019, 37(9): 1002-1008

[21] HughesI D, DaneM, ErnstA, HergertW, LüdersM, PoulterJ, StauntonJ B, SvaneA, SzotekZ, TemmermanW M. Lanthanide contraction and magnetism in the heavy rare earth elements [J]. Nature, 2007, 446(7136): 650-653

[22] WangC, LiD-qian. Extraction Mechanism of Sc(III) and separation from Th(IV), Fe(III) and Lu(III) with bis(2, 4, 4-trimethylpentyl)phos- phinic acid in N-hexane from sulphuric acid solutions [J]. Solvent Extr Ion Exch, 1994, 12(3): 615-631

[23] JayachandranJ, DhadkeP M. Solvent extraction of titanium (IV) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester (HEHEHP) [J]. J Chem Eng Jpn, 1998, 31(3): 465-468

[24] MichelsenO B, SmutzM. Separation of yttrium, holmium, and erbium with di-(2-ethylhexyl) phosphoric acid in chloride and nitrate systems [J]. J Inorg Nucl Chem, 1971, 33(1): 265-278

[25] ZhaoJ-m, HuoF, PanF, LiD-q, LiuH-zhou. Distribution behaviors of light rare earths by di-(2-ethylhexyl) 2-ethylhexyl phosphonate in kerosene under the action of a self-salting-out effect [J]. Ind Eng Chem Res, 2014, 53(4): 1598-1605

[26] HuangX-w, DongJ-s, WangL-s, FengZ-y, XueQ-n, MengX-long. Selective recovery of rare earth elements from ion-adsorption rare earth element ores by stepwise extraction with HEH(EHP) and HDEHP [J]. Green Chem, 2017, 19(5): 1345-1352

[27] ZhuX-b, LiW, TangS, ZengM-j, BaiP-y, ChenL-jian. Selective recovery of vanadium and scandium by ion exchange with D201 and solvent extraction using P507 from hydrochloric acid leaching solution of red mud [J]. Chemosphere, 2017, 175365-372

[28] ZhangF-y, DaiJ-j, WangA-m, WuW-yuan. Investigation of the synergistic extraction behavior between cerium (III) and two acidic organophosphorus extractants using FT-IR, NMR and mass spectrometry [J]. Inorg Chim Acta, 2017, 466: 333-342

[29] DongJ-s, XuY, WangL-s, HuangX-w, LongZ-q, WuS-xi. Thermodynamics and kinetics of lutetium extraction with HEH(EHP) in hydrochloric acid medium [J]. J Rare Earths, 2016, 34(3): 300-307

[30] TkacP, VandegriftG F, LumettaG J, GelisA V. Study of the interaction between HDEHP and CMPO and its effect on the extraction of selected lanthanides [J]. Ind Eng Chem Res, 2012, 51(31): 10433-10444

[31] ZhaoQ, LiY-l, KuangS-t, ZhangZ-f, BianX, LiaoW-ping. Synergistic extraction of heavy rare earths by mixture of α-aminophosphonic acid HEHAMP and HEHEHP [J]. J Rare Earths, 2019, 37(4): 422-428

[32] ChenK-h, HeY, SrinivasakannanC, LiS-w, YinS-h, PengJ-h, GuoS-h, ZhangL-bo. Characterization of the interaction of rare earth elements with P507 in a microfluidic extraction system using spectroscopic analysis [J]. Chem Eng J, 2019, 356: 453-460

[33] LiD-q, ZhangJ, XuMin. Studies of extraction mechanism of rare earth compounds with mono (2-ethyl hexyl) 2-ethyl hexyl phosphonate (HEH (EHP)) [J]. Chin J Appl Chem, 1985, 2(2): 17-23(in Chinese)

[34] FerrisT D, ZeidlerM D, FarrarT C. The concentration dependence of the proton chemical shift and the deuterium quadrupole coupling parameter for binary solutions of ethanol [J]. Mol Phys, 2000, 98(11): 737-744

[35] LiaoC-s, JiaJ-t, ZhangY, XuG, YanC-h, LiB-g, XuG-xian. Extraction of scandium from ion-adsorptive rare earth deposit by naphthenic acid [J]. J Alloys Compd, 2001, 323–324: 833-837

[36] BabaY, FukamiA, KubotaF, KamiyaN, GotoM. Selective extraction of scandium from yttrium and lanthanides with amic acid-type extractant containing alkylamide and glycine moieties [J]. RSC Adv, 2014, 4(92): 50726-50730

[37] WuD-b, XiongY, LiD-qian. Studies on the roles of different components in cyanex 302 for rare earth ions extraction and separation [J]. Sep Sci Technol, 2006, 41(8): 1725-1739