Solvent Extraction Separation Research Articles

Process optimization and mechanism for the selective extraction of copper(ii) from polymetallic acidic solutions using a polymer inclusion membrane (PIM) with Mextral®5640H as the carrier.

This study introduces a novel approach by integrating solvent extraction and polymer inclusion membrane (PIM) separation technologies to engineer an innovative PIM membrane material for the selective separation and enrichment of strategic metals, particularly copper, from polymetallic acidic solutions. The primary objectives were to streamline the technological process, reduce production costs, and enhance separation coefficients between copper and other metals. The optimal extraction conditions were determined as a mass fraction of Mextral®5640H : PVC : NPOE = 3 : 3 : 4, extraction temperature of 35 °C, and 0.9 mol L-1 H2SO4 in the stripping solution. Under these conditions, we achieved remarkable extraction efficiencies, with copper reaching 100%, and the separation coefficients between Cu2+ and Ni2+, Co2+, and Zn2+ exceeding 106. To elucidate the substantial differences in extraction performance between Cu2+ and the other metals (Ni2+, Co2+, and Zn2+), we employed an integrative analytical approach that combines FT-IR spectroscopy, BET analysis, and theoretical calculations. All extracted complexes demonstrated molecular sizes compatible with PIMs, underscoring the critical role of stability and back-extraction performance in the selective extraction of these metal ions.

Theoretical Study of Am(III) and Eu(III) Separation by a Bipyridyl Phosphate Ligand.

Actinide An(III) and lanthanide Ln(III) are known to exhibit similar chemical properties; thus, it is difficult to distinguish them in the separation of highly radioactive waste liquids. One potential method to efficiently separate actinides and lanthanides involves the design and development of phosphorus-oxygen-bonded ligands with solvent extraction separation. Here, a bipyridine phosphate ligand with two isopropyl and phosphate groups is introduced to selectively extract actinides. The electronic structure, bonding properties, thermodynamic behavior, and quantum theory of atoms in molecules (QTAIM) of Am(III) and Eu(III) complexes with the bipyridine phosphate ligands were analyzed by using density functional theory (DFT) calculations. The analysis demonstrates that the Am-N bond exhibits stronger covalent characteristics than the Eu-N bond, indicating that the bipyridine phosphate ligand had better selectivity for Am(III) than for Eu(III) in terms of binding affinity. The thermodynamic analysis established the complex [ML(NO3)2(H2O)2]+ as the most stable species during the complexation process. The results indicate great potential for utilizing the bipyridine phosphate ligand for the effective separation of An(III)/Ln(III) in spent fuel reprocessing experiments.

Development of Highly Efficient Solvent Extraction Separation Systems for Metal Ions Utilizing the Characteristics of Ionic Liquids

Development of Highly Efficient Solvent Extraction Separation Systems for Metal Ions Utilizing the Characteristics of Ionic Liquids

The Extraction of Oxalate Acid from Porang Flour (Amorphophallus oncophyllus) using Microwave-Assisted Solvent Extraction

Porang (Amorphophallus oncophyllus) is one of the local annual plants that contain high levels of oxalate. Oxalates are undesirable compounds in porang flour, and their levels must be removed or reduced to obtain high quality porang flour as a food ingredient. In this research, the extraction of oxalate acid was conducted using microwave-assisted solvent extraction and mechanical separation methods. This study aims to analysis the parameters that influence the extraction of oxalate acid using microwave-assisted solvent extraction such as the effect of microwave power, extraction time, feed-to-solvent ratio (F/S) and material size. The mechanical separation process will be studied the effect of material size for extraction of oxalate acid. The optimum yield obtained for oxalate acid extraction with microwave-assisted solvent extraction was microwave power of 600 W, extraction time of 30 min, feed-to-solvent ratio of 0.05 g/mL and porang size of 100 mesh obtained by oxalate acid yield of 24.78%. Porang size of 100 mesh was the optimum yield obtained for extraction of oxalate acid using mechanical separation method. The result of physical properties test using SEM-EDX and FTIR shows that extraction of oxalate acid from porang using microwave extraction method could produce oxalic acid which has good quality. In addition, extraction using microwave offers an environment-friendly extraction method, which can accelerate and increase the oxalate acid extraction yield.

A Comparative Study on Recent Developments for Individual Rare Earth Elements Separation

Facilitating the demands of modern society, namely, smartphones, televisions, electric vehicles, and high-stability aircraft structures, requires low-cost and high-performance materials and a corresponding change in the approach needed to design them. Rare earth elements (REEs) play a significant role in achieving these objectives by adding small amounts of these elements to alloys, thereby enhancing material properties. Despite being more abundant than precious metals, the 17 REEs exhibit subtle variations in their chemical and physical characteristics. Thus, their separation is still crucial for industrial applications. There is a corresponding need to develop more effective and efficient separation methods. Adding to the separation challenge is the complexity of the sources of REEs and related materials. Thus, large-scale production of REE materials is difficult. Current REE processing techniques can be categorized into pre-treatment, beneficiation, separation, and refining. Researchers have developed various technologies encompassing chemical, physical, and biological methods, focusing on economic and environmental considerations. However, not all these approaches can be scaled up for mass production. This article focuses on feasible strategies such as precipitation and crystallization, oxidation and reduction, ion exchange, adsorption, solvent extraction, and membrane separation. Further research into these traditional and modern methods can potentially revolutionize the separation dynamics of REEs.

Solvent Extraction Separation of Uranium, Plutonium, and Fission Products in Carbonate Media with Methyltrioctylammonium Carbonate

Solvent Extraction Separation of Uranium, Plutonium, and Fission Products in Carbonate Media with Methyltrioctylammonium Carbonate

Особенности экстракционной сернокислотно-фторидной технологии переработки ниобий- и танталсодержащего сырья

The results of researching of the leaching of niobium- and tantalum-containing raw materials by solutions of hydrofluoric and sulfuric acids are presented. Researching have been carried out on the solvent extraction purification and separation of niobium and tantalum from their fluoride-sulfuric acid solutions to obtain niobium oxides and tantalum oxides of the required quality using octanol-1 as an extractant. The possibility of recycling waste technological sulphate-fluoride solutions with the production of magnesium sulfate heptahydrate is shown. Information on the work on the use of pyrohydrolysis as a reagentless method for the isolation of products and the regeneration of hydrofluoric acid is presented.

Effect of solvation-dehydration of quaternary ammonium base salts in the organic phase on the selectivity of anion-exchange extraction

ABSTRACT The analysis of the influence of dehydration and solvation (by proton-donor reagents) of halide anions in the organic phase on the processes of their solvent extraction separation with salts of quaternary ammonium bases has been carried out. The possibility of a significant increase in the separation factors of anions in the F-Cl-Br-I series due to endothermic dehydration of amine salts (Aliquat 336) in systems with “weak” proton-donor reagents, such as chloroform has been shown. In particular, the separation factors of the Cl/F pair increase by almost 15 times when going from Aliquat 336 solutions in toluene to extractant solutions in chloroform, for the Br/Cl pair, this increase is up to 5 times, and for I/Cl, about 3 times. In similar systems with additions of alcohols and phenols to the extractant (exothermic dehydration), there is a significant deterioration in the separation parameters of halides. The conclusions are confirmed by the data of 1H NMR studies, which also made it possible to establish some details of the processes of dehydration of amine salts in the studied systems.

Recovery and Reuse of Valuable Chemicals Derived from Hydrothermal Carbonization Process Liquid

Recovery and reuse of valuable chemicals from hydrothermal carbonization process liquid (HTC-PL) from tomato plant biomass (TPB) was conducted. Different HTC-PLs were characterized with FTIR and Py-GC-MS analyses revealing the presence of low molecular weight linear, cyclic, and aromatics compounds in the HTC-PL. Separation of these valuable chemicals by fractional distillation resulted in eutectic constrains. Solvent extraction separation followed by solvent recovery and reuse provided encouraging results. The non-polar portion of HTC-PLs were extracted by using n-hexane (C6H14), and diethyl ether (C2H5)2O solvents with 8.5 and 4.3% recoveries, respectively. Characterization by FTIR and Py-GC-MS revealed petrol fuel like materials in the extracts of C6H14 and (C2H5)2O, irrespective of higher boiling components. Blends of both non-polar extracts were flame tested revealing good burning characteristics with minimal smoke and residue. Bench scale spirit lamp tests showed the blend would be very useful for greenhouse winter heating. The polar extracts using methylene chloride (CH2Cl2) resulted in about 55% recovery. Py-GC-MS analysis revealed acetic acid and 5-Hydroxymethyl furfural (5HMF) majors in the extract along with related derivatives. 5HMF is a valued chemical and demonstrated to be a useful building block for many industrial applications, and flatform chemical for various synthesis. Other identified minor components of HTC-PL were vanillin, divinyl terephthalate, and syringol. After the extractions of polar and non-polar components in three steps, the HTC-PL residue was applied as nutrient source after maintaining pH (5.6) and concentration (TOC, 100–200 mg/L) to typical greenhouse plants. Plant growth was encouraging. The paper discusses all the potential valued reuse applications of HTC-PL in greenhouses without discharges, which contributes to environmental protection and economic benefits.

Simultaneous determination of hexabromocyclododecanes, polybrominated diphenyl ethers, and dechlorane-related compounds in boxed sushi meals using a developed analytical method

We investigated the concentrations of halogenated flame retardants (HFRs), which include hexabromocyclododecanes (HBCDDs), polybrominated diphenyl ethers (PBDEs), and dechloranes and related compounds (DRCs), in 25 typical ready-made boxed sushi meals (each divided into seafood and non-seafood portions) using a developed simultaneous analytical method involving accelerated solvent extraction and gel permeation chromatographic separation. The developed method yielded good recoveries of surrogates (72–122 %). HBCDDs, PBDEs, and DRCs were detected in all seafood portions. While DRCs were also frequently detected in non-seafood portions, HBCDDs and PBDEs were hardly detected. The estimated dietary intakes of HBCDDs, PBDEs, and DRCs from boxed sushi meals were well below the corresponding health-based guideline values. In conclusion, our study suggests that the intake of HFRs from boxed sushi meals poses low concern for consumer health and that the developed simultaneous analytical method is highly useful for determining HFRs in seafood-based meals.

Extensive investigation on extraction behaviour of organo-phosphrous based bi-functional ionic liquids for separation of molybdenum (Mo) from spent Co-Mo/Al2O3 leach liquor

The sulphate mediated spent catalyst Co-Mo/Al2O3 leached liquor bearing ∼ 6.05 g/L of Mo, 1.75 g/L of Al and 1.44 g/L of Co was subjected to the solvent extraction separation of Mo using noble bi-functional ionic liquids (BILs). Comparative extraction behaviour of Mo with two BILs such as quaternary ammonium D2EHPA(R4ND) and quaternary ammonium Cyanex 272 (R4NCY) synthesized from Aliquat 336 in combination with D2EHPA and Cyanex 272 was systematically investigated. The purity of synthesized ILs was ascertained from NMR analysis. The role of both BILs concentrations appears to be critical on extraction of Mo at acidic pH ranges of the solution with an association of 1 mol each as evident from slope analysis equilibrium study. The Extraction of Mo as H2MO4 at optimum solution pH of 2.0 gives rise to achieve a selective separation of Mo in presence of Co and Al as ensured from separation factor (S.F.) value; βMo/Co = 5388.8 and 1642.5 for R4ND and R4NCY and βMo/Al = 1309.2 and 13522.1 for R4ND and R4NCY respectively. The extraction yield of Mo with ILs was enhanced while increasing the temperature of the solution as indicated from the positive ΔH (+40.26 KJ/mol & 73.27 βMo/Co = 5388.8 and 1642.5 for R4ND and R4NCY and βMo/Al = 1309.2 and 13522.1 for R4ND and R4NCY) values. The diluents effect on Mo extraction was consistent with either of the ILs and they follows the order as n-Hexane > Tolune > Kerosene > Benzene > Xylene. The Mc-Cabe Thiele plot constructed at A: O = 5:1 has predicted 2 stages using 0.6 M each of R4ND and/or R4NCY and later it was validated from CCS leading to attain>99.9 % Mo extraction. The extraction behaviour of R4NCY was efficient and effective on clean separation of Mo over R4ND at the studied experimental condition. Stripping of Mo-loaded-R4NCY by NH4OH was promising with the Mo enrichment up to 3 times with generation of purified stripped bearing 90.71 g/L of Mo. FTIR characteristic peak of R4ND and R4NCY before and after extraction confirms in support of the Mo extraction with ILs. The purity of synthesized ILs was ascertained from NMR analysis.

Direct Production of Ni–Co–Mn Mixtures for Cathode Precursors from Cobalt-Rich Lithium-Ion Battery Leachates by Solvent Extraction

A novel solvent extraction scheme was developed for the processing of Co-rich lithium-ion battery (LIB) leachate to a Ni–Co–Mn (NCM) sulfate mixture that can be directly used in the precursor synthesis of LIB cathodes. Conventional hydrometallurgical recycling of spent LIBs usually aims at separation of Li, Ni, Co, and Mn into pure fractions, which is simplified here. Operating pH and the number of extraction stages for each separation were evaluated from batch equilibrium experiments. Two continuous countercurrent extractions with bis(2-ethylhexyl) hydrogen phosphate (D2EHPA) and one with Cyanex 272 were studied in bench-scale mixer-settler equipment, and a Ni–Co–Mn solution with n(Ni):n(Co) = 14.16 and n(Ni):n(Mn) = 8.06 was obtained. The Ni:Co:Mn molar ratio in the NCM mixture can be adjusted to, for example, 8:1:1 using a Co-rich raffinate from the same process, and no additional transition metal salts are required for tuning the composition. Stripping raffinate containing 102.7 g L−1 Co at 99.8% relative purity was obtained from Cyanex 272 extraction. The main benefit of the process concept is that the solvent extraction separations can be operated with less stringent requirements than when producing pure metal salts.

Determination and correlation of LLE data for the separation of ethylene glycol and ethylene glycol diacetate

Ethylene glycol diacetate (EGDA) is a kind of environment-friendly organic solvent with high boiling point, which has broad application prospect in chemical production. For the optimization of ethylene glycol (EG) – EGDA mixture solvent extraction separation, o-xylene, m-xylene and ethylbenzene were used as extractants to measure the liquid–liquid equilibrium data of EG + EGDA + extractants ternary system at 303.2 K and 323.2 K under 101.3 kPa, respectively. The extraction and separation performance of extractant was evaluated by separation factor. The results show that the separation factor of the solvent is greater than 1, o-xylene, m-xylene and ethylbenzene can effectively separate EGDA. NRTL and UNIQUAC thermodynamic models are used to correlate experimental data and obtain corresponding binary interaction parameters. The calculated relative root mean square deviations (RMSD) are all less than 0.01, indicating that NRTL and UNIQUAC can correlate experimental data well. In order to verify the reliability of the binary interaction parameters, the graphical user interface developed by MATLAB is used for topology analysis.

Integration of solvent extraction and membrane processes to produce an oleuropein extract from olive leaves

The integration of solvent extraction and membrane separation technology was used to recover and concentrate oleuropein from olive leaves. In this study, the effect of extraction solvent (type, composition) on the content of total phenolic compounds (TPC) extracted from olive leaves was investigated. Experimental results showed that ethanol:water, 75 %/25 % (v/v), gives the highest TPC. Thus, to establish the parameters to obtain hydroethanolic olive leaves extract with the highest content of total phenolic compounds, a Central Composite Design was performed. The extract obtained at 50 °C for 90 min, within 0.03 g/ml, was subjected to crossflow ultrafiltration (UF) to remove suspended solids in the feed and to reduce fouling phenomena, followed by a stirred dead-end nanofiltration (NF) using a commercial flat sheet membrane at different pressure (10, 20 and 30 bar). The nanofiltration (at 30 bar) showed a high rejection coefficient towards phenolic compounds and flavonoid contents. Fractions coming from UF and NF (at 30 bar) revealed that the highest content of oleuropein was 119.01 mg/g corresponding to NF retentate, high antioxidant capacity (DPPH method). Conductivity, sanity, turbidity, pH, TDS, and TSS of different fractions were also determined. It can be concluded that the integration of solvent extraction and membrane separation technology is efficient for the recovery and concentration of oleuropein and phenolic compounds from olive leaves. The obtained concentrate is of interest for preparing formulations to be used in the food, cosmetic and pharmaceutical industries.

A review of environmental aspect of rare earth element extraction processes and solution purification techniques

• Various aspects of rare earth elements were compiled from a global perspective. • New research initiatives and resource exploration on rare earths were investigated. • The environmental impact of rare earth element extraction was reviewed. • Regulatory approaches for radioactivity issues and waste disposal were addressed. • Separation processes for thorium, uranium and rare earth elements were reviewed. Rare earth elements (REEs) are vital for the technology, military, and defense industries. They have been recognized as critical due to potential scarcity, supply constraints, and lack of minable concentrations. Therefore, alternative sources are needed to meet the demand and continue manufacturing rare earth-dependent products. However, the environmental prospect of rare earth mining was not investigated enough, and comprehensive studies are lacking. It demands serious consideration as toxic radionuclides are seen in the same mineralization as rare earths regardless of their primary or secondary sources. The concentration of these hazardous trace elements may be elevated as a result of extraction and beneficiation processes. Unless proper separation and disposal are performed, these radionuclides accumulate on the surface of the soil or integrate with aquatic systems, which consequently raise environmental and health concerns. This review manuscript compiled the environmental impact and aspect of rare earth extraction processes while addressing separation techniques for these radioactive materials from rare earths, emphasizing selective precipitation, solvent extraction, and solid-phase separation.

Separation of Rare-Earth Elements from Nitrate Solutions by Solvent Extraction Using Mixtures of Methyltri-n-octylammonium Nitrate and Tri-n-butyl Phosphate.

The article presents data on the solvent extraction separation of rare-earth elements (REEs), such as La(III), Ce(III), Pr(III), and Nd(III), using synergic mixtures of methyltrioctylammonium nitrate (TOMANO3) with tri-n-butyl phosphate (TBP) from weakly acidic nitrate solutions. Specifically, experimental results on separation of REEs, for the pair Ce(III)/Pr(III) for quaternary mixtures of REEs (La(III), Ce(III), Pr(III), Nd(III)) and for the pair La(III)/Pr(III) for solutions containing La(III), Pr(III), and Nd(III), are presented. It was shown that effective separation for the pair Ce(III)/Pr(III) from a solution containing 219 g Ce(III)/L, 106 g La(III)/L, 20 g Pr(III)/L, 55 g Nd(III)/L, and 0.1 mol/L HNO3, was achieved using 56 steps of a multistage, counter-current solvent extraction cascade with scrubbing, at an organic-to-aqueous phase volume ratio (O/A) equal to 2/1 on the extraction section and O/A equal to 4/1 on the scrubbing section, using 3.3 mol/L solutions of the mixture TOMANO3-TBP with molar ratio 0.15:0.85 in dodecane. Separation for the pair La(III)/Pr(III) could be achieved using a solvent extraction cascade with scrubbing in 32 steps at O/A equal to 2/1 on the extraction section and O/A equal to 2.8/1 on the scrubbing section of the solvent extraction cascade from a solution containing 258 g La(III)/L, 58 g Pr(III)/L, 141 g Nd(III)/L, and 0.1 mol/L HNO3 with 3.0 mol/L solution of the mixture TOMANO3-TBP with molar ratio 0.2:0.8 in dodecane.

Environmental friendly approach for selective extraction and recovery of molybdenum (Mo) from a sulphate mediated spent Ni–Mo/Al2O3 catalyst baked leach liquor

Solvent extraction separation of molybdenum (Mo) from the sulphate mediated leach solution bearing Aluminium (Al) and Nickel (Ni) was carried out using N-Methyl-N, N, N-tri-octyl-ammonium chloride. Extensive investigation for extraction study molybdenum in the function of time, Eq.pH, extractant concentration, diluents, temperature, strip solution concentration and phase ratio(A:O) for both extraction and stripping was examined to attain a suitable condition on its selective and enriched extraction. As per the equilibrium study and increasing trend of Eq. pH (pHe) at the correspondence initial pH, it was apparent about association of 1 mol of H+ ion during extraction which with was further supported on extraction of Mo as HMO4- at the pHe of 3.48. The association of 1 mol of exrractant during the extraction of Mo was also well evident from the slope analysis study. This indicates about anion exchange phenomenon due to Cl− ion of the N-Methyl-N, N, N-tri-octyl-ammonium chloride (extractant) with HMo4− from aqueous phase during complex formation reaction. The FTIR of the organic sample before and after extraction further confirms in support of the complex formation of the molybdenum with the extractant during extraction. The extraction isotherm was constructed at optmum extraction condition: pHe of 3.48 with 0.08M N-Methyl-N, N, N-tri-octyl-ammonium chloride predicts on need of 2-counter current stages for quantitative extraction of Mo at A:O = 3:1. To investigate the regeneration behaviour of adopted extractant along with enriched stripping of molybdenum, ammoniacal reagents were used in stripping study. The stripping of Mo showed promising and efficient using the mixture of the ammoniacal reagents (NH4OH + NH4Cl) over the either of the solo reagents. The stripping Mc-Cabe Thiele diagram was plotted using 2M NH4OH + NH4Cl ensures on quantitative stripping of Mo at SO: SS = 2:1 at 2 no. of stages. Both extraction and stripping isotherm results are validated at predicted isotherm conditions by 6-cycles counter current simulation (CCS) study leading to obtain 6-fold enrichment of Mo in stripped solution phase. The subsequent enriched content of Mo (∼60 g/L) in stripped solution phase was precipitated out followed by calcinations 400 °C to obtain a high pure MoO3. The recovered calcined product as MoO3 resulted through the proposed processing approach was as ascertained from XRD analysis.

The Application of 2,6-Bis(4-Methoxybenzoyl)-Diaminopyridine in Solvent Extraction and Polymer Membrane Separation for the Recovery of Au(III), Ag(I), Pd(II) and Pt(II) Ions from Aqueous Solutions.

The work describes the results of the first application of 2,6-bis(4-methoxybenzoyl)-diaminopyridine (L) for the recovery of noble metal ions (Au(III), Ag(I), Pd(II), Pt(II)) from aqueous solutions using two different separation processes: dynamic (classic solvent extraction) and static (polymer membranes). The stability constants of the complexes formed by the L with noble metal ions were determined using the spectrophotometry method. The results of the performed experiments clearly show that 2,6-bis(4-methoxybenzoyl)-diaminopyridine is an excellent extractant, as the recovery was over 99% for all studied noble metal ions. The efficiency of 2,6-bis(4-methoxybenzoyl)-diaminopyridine as a carrier in polymer membranes after 24 h of sorption was lower; the percentage of metal ions removal from the solutions (%Rs) decreased in following order: Ag(I) (94.89%) > Au(III) (63.46%) > Pt(II) (38.99%) > Pd(II) (23.82%). The results of the desorption processes carried out showed that the highest percentage of recovery was observed for gold and silver ions (over 96%) after 48 h. The results presented in this study indicate the potential practical applicability of 2,6-bis(4-methoxybenzoyl)-diaminopyridine in the solvent extraction and polymer membrane separation of noble metal ions from aqueous solutions (e.g., obtained as a result of WEEE leaching or industrial wastewater).

Integrated microsystems for lipase-catalyzed biodiesel production and glycerol removal by extraction or ultrafiltration

Competition among renewable energy sources in today's market is growing rapidly. Renewables have grown to the point where they are taking significant material market share from coal, gas, and uranium. Recently, biodiesel production has been intensified by lipase-catalyzed transesterification performed in microsystems. Another challenge in biodiesel production is the purification of the biodiesel. Common purification methods are usually more energy and time consuming than the biodiesel production itself.In this work, an integrated biodiesel production process composed of lipase-catalyzed transesterification of sunflower oil and product purification was performed in microreactor and microseparator units connected in series. Glycerol, the by-product of the transesterification process, was removed from the reaction mixture by two different separation methods, deep eutectic solvent extraction and membrane separation. Different integrated setups were developed and evaluated in terms of FAME yield and purity. The most promising integrated process was found to be the one combining 2-inlets feeding strategy for biodiesel production in a microreactor with a microseparator connected in series, in which a choline chloride-glycerol deep eutectic solvent was used. In this integrated system, a FAME yield of 94% and a glycerol content below 0.02% (w/w) were achieved for the residence time of 20 min.

Separation of lithium isotopes by crown ether-room temperature ionic liquid-anisole friendly solvent system

The solvent extraction separation of lithium isotopes has become of growing interest due to the need for 6Li and 7Li isotopes in the nuclear industry. A one-step synthesis of room temperature ionic liquid with low viscosity 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]) (with reaction yields of 87.47%) was used by the ultrasonic method. The addition of ionic liquid [EMIm][NTf2] in the system significantly improved the extraction efficiency and separation factor compared to the traditional organic solvent anisole for extraction separation of lithium isotopes. The distribution ratio increased from 0.00145 (with the single stage separation factor of 1.024 ± 0.001) to 0.134 (with the single stage separation factor of 1.034 ± 0.001). Furthermore, a multi-stage extraction process was intended to enhance lithium isotope separation performance. Each stage of stripping can be considered as an extraction separation equilibrium process, in which the strip liquor from the load organic phase is used for separation in the next stage as the “original aqueous solution”. The abundance of 6Li+ gradually improved with an increase in the extraction stages. The relative abundance of 6Li+ increased by 1.492% at the 20-stage extraction separation (from 7.53% to 9.022%). This new and simple approach (stripping cross-flow multistage method (SCFM)) was to achieve large enrichment of lighter isotopes of lithium (6Li+) by combined extraction and stripping process. In summary, the present study offers the possibility for the enrichment of 6Li+ during lithium isotope extraction separation.