Synergistic Extraction System Research Articles

Solvent extraction of Ni and Co from Ni-laterite leach solutions using a new synergistic system consisting of Versatic 10 acid, Mextral 6103H and Aliquat 336 with elemental mass balance for leaching, precipitation, solvent extraction, scrubbing and stripping

A new synergistic extraction system containing Versatic 10 acid, Mextral 6103H and Aliquat 336 was investigated for nickel and cobalt recovery from nickel laterite leach solutions. It was found that the addition of 0.3 M Aliquat 336 could significantly improve the nickel stripping kinetics of the Versatic 10 acid and Mextral 6103H mixed system, resulting in 98.9% stripping efficiency within 2 min. The effect of Aliquat 336 on the Versatic 10 acid (V10) and Mextral 6103H mixed system in terms of extraction and stripping performance was investigated. Based on the McCabe-Thiele plots for nickel/cobalt extraction and stripping, semi-continuous tests were conducted using the employed synergistic system. Over 99% nickel and 97% cobalt were extracted via a two-stage semi-continuous extraction with a pH profile of 4.5/5.0 for E1/E2 and an O/A ratio of 2.2, resulting in less than 2.0% manganese and negligible magnesium and calcium in the loaded organic solution. More than 95% co-extracted manganese was readily scrubbed via two stages of semi-continuous scrubbing, resulting in less than 1.0 mg/L Mn left in the scrubbed organic solution. Moreover, 98.8% nickel and 99.1% cobalt could be stripped using a two-stage semi-continuous stripping with 1.5 M H2SO4. Based on the test results, a proposed process flowsheet was developed for nickel and cobalt recovery and purification.

Synthesis of N-(2-ethylhexyl)-pyridine-4-carboxamide and its synergistic behaviors with dinonylnaphthalene sulfonic acid for the selective extraction of nickel and cobalt

The hydrometallurgical process for the recovery of nickel and cobalt requires a complex and expensive impurity removal process. Solvent extraction is widely used in industry for the separation, purification, and concentration of metals. However, current commercial extractants encounter some difficulties when cobalt and nickel are extracted from solutions containing a large amount of impurities such as manganese and calcium. There is an urgent need to develop new reagents for the selective extraction of Ni and Co. In this study, N-(2-ethylhexyl)-pyridine-4-carboxamide (NEHPCA) was synthesized, and the metal extraction capacity of its synergistic solvent extraction (SSX) system with dinonylnaphthalene sulfonic acid (DNNSA) and tributyl phosphate (TBP) modifier was examined. The experimental results show that the selectivity of the new SSX system has the order Cu > Ni > Co > Zn > Mn > Ca > Al ≈ Cr (III) ≈ Mg ≈ Fe (III), with excellent selectivity for nickel and cobalt. Using an organic phase composed of 0.7 M NEHPCA, 0.35 M DNNSA, and 0.2 M TBP under 1:1O/A operation, after three-stage theoretical extraction, more than 99% of nickel and cobalt can be recovered from a synthetic leaching solution of nickel laterite ore. Mechanistic studies showed that NEHPCA and water molecules participate in the internal coordination of metals, and DNNSA provided coordination anions to achieve charge balance, forming the Ni complex in this SSX system which existed most likely in the form of [Ni(NEHPCA)2(H2O)4](DNNS)2 in the organic phase.

Recovery of Chromium (Vi) From Hazardous Apv Wastewater Using a Novel Synergistic Extraction System

Recovery of Chromium (Vi) From Hazardous Apv Wastewater Using a Novel Synergistic Extraction System

A novel synergistic extraction system for the recovery of scandium (III) from sulfuric acid medium with mixed Cyanex923 and N1923

High extraction capability and outstanding selectivity are very attractive in the solvent extraction process. Scandium (Sc(III)), as a primary rare earth element (REE), generally lacks independent large-scale deposits and is mainly recovered as a by-product during the processing of mineral. However, the difficulty of stripping has been always a crucial problem to be solved in the scandium extraction system. This study aims to improve stripping performance while enhancing extraction efficiency for scandium. Herein, a novel synergistic extraction system for the recovery of scandium with a mixture of Cyanex923 (A, a mixture of four trialkylphosphine oxides) and N1923 (B, primary amine R1R2CHNH2) in sulfuric acid medium was put forward. The effect of the molar fraction (X) of Cyanex923 on the extraction of scandium was systematically investigated. The experimental results demonstrated that the coupled Cyanex923-N1923 exhibited an obvious synergistic effect on Sc(III). The maximum synergistic enhancement coefficient (Rmax) was calculated to be 2.20 when the molar fraction (X) of Cyanex923 was 0.4, and the H2SO4 concentration was 0.25 mol·L−1. Moreover, the synergistic extraction mechanism was discussed combined with multiple techniques including slope analysis method, FT-IR and NMR characterizations, to which the structure of extracted complexed was deduced to be Sc(SO4)1.5∙(A)0.5(B). Thermodynamic experiment was also explored in detail. More importantly, stripping with only 2 mol·L−1 HNO3 produced a relatively high stripping rate of 95%. The synergistic system still presented excellent reusability even after five treatment cycles. Finally, this study pointed out a potential industrial application value for the separation and recovery of Sc(III) from the sulfuric acid leaching liquor of nickel laterite ores.

Comprehensive recovery of metals in spent Ni–Mo/γ–Al2O3 hydrofining catalyst

This study proposes a technical route toward the comprehensive recovery of valuable metals from spent Ni–Mo/γ–Al2O3 hydrofining catalysts, which were employed to remove S, N, and O elements and metal–organic compounds from crude oil and petroleum products. Additionally, the process conditions are optimized, thereby providing good economic and environmental benefits. Sodium carbonate-assisted roasting of the spent catalyst effectively improves the secondary pollution and leaching effect. After Al, Mo, and Ni elements in the spent catalyst were converted into NaAlO2, Na2MoO4, and NiO, more than 99.8% of the metal ions entered the leaching solution, minimizing the loss. A synergistic extraction system using the di-(2-ethylhexyl)phosphoric acid (P204) and tri-n-octylamine (TOA) extractants were employed to extract molybdenum from the clarified acid leaching solution, and more than 97.5% of Mo was separated from Al and Ni. The MoO3 product was obtained by stripping with ammonia, followed by evaporating, and roasting. Furthermore, by adding ammonia to adjust the pH value of the molybdenum extraction solution to 4, 98.0% of the Al was extracted by P204. Subsequently, a Na2S precipitation agent was employed to convert Ni2+ into Ni(OH)S with a precipitation efficiency of 97.9%. Ultimately, the comprehensive recovery efficiencies of Al, Mo and Ni were 97.5%, 95.5%, and 90.9%, respectively, thereby realizing the comprehensive recovery of metals in the spent catalyst.

Treatment of cyanide-bearing wastewater by the N263-TBP synergistic extraction system

In this study, a trioctylmethylammonium chloride (N263)- tributyl phosphate (TBP)-n-octanol-sulfonated kerosene (N263-T) synergistic extraction system and an N263-n-octanol-sulfonated kerosene (N263–O) system were used to treat cyanide (CN)-bearing wastewater. The extraction saturation capacity of the two systems was measured. The influences of the initial pH and phase ratio (O/A) of the two systems on extraction were compared and analyzed. Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, and slope methods were used to analyze the characteristic functional groups in the loaded organic phase, the compositions of the extracted compounds in the extraction reactions and the reaction mechanism. The results indicated that the saturated extraction capacity of the N263-T system, which was much larger than that of the N263–O system, for metal CN complex ions was 4354.31 mg/L. In addition, the N263-T system operated over a wider pH range. The extraction rates of copper (Cu), zinc (Zn), and iron (Fe) ions at pH 14 were 97.4%, 99.1%, and 87.2%, respectively. There was a strong compatibilization effect of TBP on the extraction system. The extraction efficiency of the N263-T system for metal CN complex ions was higher than that of the N263–O system when O/A = 0.4. The saturated loaded N263-T and N263–O systems were stripped by 1 mol/L NaOH +2 mol/L NaSCN solution at O/A = 3. The metal ion concentration in the stripping solution could be enriched to 11996.6 and 8913.3 mg/L for the N263-T and N263–O systems, respectively. During the extraction process, the binding ratios of N263 cations to Cu(CN)32−, Zn(CN)42−, and Fe(CN)63− were 2:1, 2:1, and 3:1, respectively. The binding ratios of TBP to Cu(CN)32−, Zn(CN)42−, and Fe(CN)63− in wastewater were 3:1, 4:1, and 6:1, respectively. The PO group in TBP was linked to the CN group of the metal CN complex ion by hydrogen bonds using the water molecule as a bridge to form a supramolecular anion group, which entered into the organic phase and combined with the N263 cation under the action of ion association.

Recycling of residual valuable metals in cyanide-leached gold wastewater using the N263-TBP system

In this study, the synergistic extraction system of trioctylmethyl ammonium chloride (N263)-tributyl phosphate (TBP)-n-octanol-sulfonated kerosene was used to enrich and recover valuable metals from cyanide gold extraction of wastewater. The effects of the proportion of N263 and TBP, contact time, initial pH of water phase, temperature, and phase ratio (O/A) on the extraction percentage of metal cyanide complex ions and the synergistic extraction reaction mechanism were mainly investigated. Results showed that the single-stage extraction percentages of Cu, Zn, and Fe ions in wastewater were 99.87%, 99.8%, and 96.2%, respectively, and the saturated extraction capacity was 4356.4 mg/L under the conditions of N263 (20 vol%)-TBP (20 vol%)-n-octanol (10 vol%)-sulfonated kerosene system at 25 °C, O/A of 1:1, pH of 10, and contact time of 5 min. Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS) analyses showed that metals entered the organic phase in the form of metal cyanide complex ions during extraction. Metal cyanide complex ions preferentially combined with TBP to lose hydrophilicity and then reacted with N263 cations to enter the organic phase. The saturated organic phase was stripped by NaOH and NaSCN mixed solution, and the total concentration of metal ions in the stripping solution reached 11,996.6 mg/L.

Highly efficient recovery and purification of scandium from the waste sulfuric acid solution from titanium dioxide production by solvent extraction

The waste sulfuric acid solution generated from titanium dioxide production is called titanium dioxide waste acid (TWWA), which is an important resource for scandium production. A way including enrichment and purification stages for recovery and purification of Sc from TWWA with 10% P204 - 5% TBP synergistic extraction system was studied. In the enrichment stage, the preferred experimental conditions were obtained, i.e., the A/O ratio: 30, 25 °C, contact time: 30 min. In the following purification stage, the above-obtained enrichment products by stripping with 5 M NaOH were dissolved with 3 M HCl with 1% H2O2 added. The added H2O2 can lead to Ti form peroxy complex ([TiO(H2O2)]2+) that can effectively inhibit its co-extraction into the oil phase. The optimized purification conditions were the A/O ratio of 5, 30 min and 11 mmol/L Sc concentration. The stripping products obtained from the purification stage were dissolved with 2 M HCl, and then 0.5 M H2C2O4 was added to precipitate scandium. After washing and calcining, a product of 99.28% Sc2O3 was obtained. The recovery rate of scandium in the whole process was 90.34%.

Solvent extraction-based recovery of Co from leach solutions of Cu[sbnd]Co ores using a Mextral 6103H-naphthenic acid- isooctanol system

A Mextral 6103H–naphthenic acid–isooctanol synergistic extraction system was used for the selective separation of Co from pre-treated leach solutions of CuCo ores and the extraction performance, the extraction/stripping kinetics, and the phase separation properties of this system were determined. At pH 4.0, Co was selectively extracted from the feed solution containing Co, Ni, Zn, Mg, Mn, and Ca. The Co-loaded organic phase was easily stripped with a solution containing Co (100 g/L) and H2SO4 (40 g/L) at an O/A ratio of 5:1 and 25oC. Based on the McCabe-Thiele plots for Co extraction, scrubbing and stripping, tests involving simulated batch counter-current extraction (two stages), scrubbing (two stages) and stripping (two stages) were performed. A Co extraction efficiency of 99.7% (over two extraction stages) was obtained, while nearly all Mg, Mn, and Ca remained in the raffinate. The two-stage scrubbing of the co-extracted loaded organics resulted in the efficient removal of Zn (88.3%), Mn (95.2%), Mg (94.0%), and Ca (92.0%). The two-stage stripping of Co had an efficiency of 99.1%. The stripping liquor contained low levels of Zn (3.4 mg/L), Ni (0.2 mg/L), Mn (2.4 mg/L), Mg (1.2 mg/L) and Ca (0.8 mg/L), with the resulting Co purity equaling 99.98%. Thus, the developed process holds great promise for the selective recovery of Co from the leach solutions of CuCo ores containing multiple metals

Mechanism of Ferric Chloride Facilitating Efficient Lithium Extraction from Magnesium-Rich Brine with Tri-n-butyl Phosphate

The synergistic solvent extraction system comprising tri-n-butyl phosphate (TBP) and FeCl3 has been intensively studied for selective extraction of Li(I) from Mg(II)-rich brine. The extraction occurs via the formation of an ion-pair complex [Li(TBP)x][FeCl4] in which the negatively charged [FeCl4]− neutralizes the positively charged [Li(TBP)x]+. Counterintuitively, many other metal chlorides give much lower Li(I) extraction efficiency than FeCl3, although they can also form chlorometallate anions similar to [FeCl4]−. In this study, the capabilities of CuCl2, AlCl3, InCl3, and SnCl4 for Li(I) extraction with TBP were examined and compared with that of FeCl3, accompanied by speciation studies. It was found that (1) AlCl3 does not form [AlCl4]− while other metal chlorides (CuCl2, InCl3, FeCl3, and SnCl4) can form chlorometallate anions that could facilitate Li(I) extraction and (2) CuCl2, InCl3, and SnCl4 form neutral solvation complexes with TBP strongly, which hinders the formation of chlorometallate anions, but FeCl3 does not form neutral complexes with TBP. Concurrently being able to form [FeCl4]− and to avoid forming neutral complexes facilitates the efficient Li(I) extraction by FeCl3 with TBP.

Synergistic solvent extraction of lanthanide ions with mixtures of D2EHPA and MIDPA in phosphonium-based ionic liquids

In this study, the synergistic solvent extraction of lanthanide(III) with mixtures of di-(2-ethylhexyl)phosphoric acid (D2EHPA, H2A2) and monoisodecyl phosphoric acid (MIDPA, H2B2) in phosphonium-based ionic liquid was investigated from amide acid medium. The method of slope analysis was used for the determination of the extraction reaction. In the case of D2EHPA or MIDPA single extractant system, Ln(III) (Ln = Pr and Nd) was extracted as [LnA3HA] or [LnB3HB], respectively. Tb(III) or Dy(III) were extracted as [TbH2A2B2(NTf2)] or [DyH2A2B2(NTf2)] instead of [TbA3HA(NTf2)] or [DyA3HA(NTf2)] for D2EHPA and MIDPA synergistic system. According to the equilibrium constants (KA, KB and KAB) and the formation constants (β1, β1 and β3), it was found that the extracted complex [TbHA2B2] or [DyHA2B2] was more stable than [LnA3HA] or [LnB3HB] due to the synergistic effect of D2EHPA and MIDPA. The thermodynamic functions (ΔH, ΔG, and ΔS) were estimated from the temperature dependence of the synergistic extraction system. The result indicated that the synergistic extraction reaction was endothermically driven for this extraction system. Furthermore, the synergistic extraction effects were investigated to study the possibility of separating Dy(III) from Pr(III) and Nd(III) according to their separation factors.

A novel neutral-base coupling synergistic extraction system of Cyanex923 and primary amine N1923 for the recovery of cerium(IV) and fluorine from sulfuric acid medium

Cyanex923 (A) and primary amine N1923 (B) mixture was developed as a novel neutral-base coupling extraction system for the recovery of cerium(IV) (Ce(IV)) and fluorine (F−) from sulfuric acid (H2SO4) medium. This system demonstrated excellent synergistic effects for both Ce(IV) and F− extraction. In Ce(IV) solution, the maximal synergistic coefficient (Rmax) for Ce(IV) was 2.93 at the Cyanex923 mole fraction (X) of 0.6. In Ce(IV)-F− solution, the presence of F− enhanced the synergistic extraction of Ce(IV) with the Rmax-Ce(IV) of 4.39 at XCyanex923 = 0.6, meanwhile the synergistic coefficient for F− (Rmax-F−) reached 4.33. The synergistic extraction mechanisms were systematically studied through multiple techniques including stoichiometry analysis, FT-IR and NMR characterizations. Equilibrium structures of extracted complexes were determined as Ce(SO4)2∙(A)1.5(B) and CeF(SO4)1.5∙(A)(B). Thermodynamic investigations revealed that the synergistic extraction processes were spontaneous. Specifically, the extraction process for Ce(IV) was endothermic and entropy driven, while the extraction process for Ce(IV)-F− was exothermic and enthalpy driven. The extracted Ce(IV) and F− can be almost stripped completely using HNO3 with additive H2O2, and CeF3 particles were obtained by reductive stripping from Ce(IV)-F− loaded organic phase as confirmed by XRD, SEM and DLS. The Cyanex923-N1923 system achieved comprehensive recovery of Ce(IV) and F− from the Bayan Obo mixed RE H2SO4 liquor and this excellent synergistic extraction performance suggests its high practical application potential.

Recovery of scandium from spent sulfuric acid solution in titanium dioxide production using synergistic solvent extraction with D2EHPA and primary amine N1923

High-efficiency and good-selectivity extraction systems are very attractive in the solvent extraction process. A synergistic extraction of scandium (III) from a spent sulfuric acid solution of titanium dioxide production by using a mixture of bis-2-ethylhexyl phosphoric acid (D2EHPA, P204) and primary amine (N1923) has been proposed in this study. The effect of the molar fraction of N1923 in the mixed extractants on the extraction of scandium was studied and the synergistic enhancement coefficient R was calculated. The maximum synergistic coefficient was found to be 12.50 when the H2SO4 concentration was 0.5 mol·L−1 and the molar fraction of N1923 was 0.5. The synergistic extraction mechanism was also discussed. Appropriately 90% scandium could be stripped from the loaded organic phase in the synergistic extraction system when the nitric acid was 6 mol.L−1. The result of FT-IR spectra well verified the conclusion that the synergistic effect owed to the formation of hydrogen bond NH+···OP, causing a much easier dissociation of proton H of P204. Finally, after three-stage counter-current extraction and stripping, Sc2O5 product with a high purity of 90% was obtained from spent sulfuric acid solution by precipitation and calcination.

Extraction Mechanism of Lithium from the Alkali Solution with Diketonate-Based Ionic Liquid Extractants

Four diketonate-based functional ionic liquids (ILs) with trialkylmethylammonium ([A336]+) cation were synthesized, and the synergistic extraction systems containing IL and thetrialkylphosphineoxid...

Highly selective transport of lithium across a supported liquid membrane

Lithium extraction is a major concern in view of the increase in battery manufacturing. Separation of lithium from associated sodium is still a challenging task due to the similar chemical behavior of these alkali metals. Lithium sources such as salt brines or seawater usually contain large amounts of sodium which requires a high selectivity for the lithium extraction process. In this study, we demonstrate the application of a supported liquid membrane (SLM) with very high selectivity for the separation of lithium from sodium. A synergistic extraction system made of heptafluoro-dimethyloctanedione (HFDOD) and tri-n-octylphosphine oxide (TOPO) ligands diluted in dodecane was selected based on its extraction efficiency (>99 % of lithium extracted) and selectivity for lithium over sodium (separation factor ca.400). Several experimental parameters were studied using a SLM made of HFDOD and TOPO (initial lithium concentration and sodium to lithium concentration ratio in the feed aqueous phase, HFDOD: TOPO ratio in the organic phase). It was found that high lithium permeation rates can be obtained even for low lithium concentrations and high sodium concentration. Membrane stability was evaluated and found to be poor, i.e. significant loss of performances was observed after one cycle of use, due to the leakage of the organic phase and change in HFDOD: TOPO ratio into it. The SLM system designed is suitable for the extraction of lithium from lowly concentrated solutions such as brines and seawater.

Combining Selective Extraction and Easy Stripping of Lithium Using a Ternary Synergistic Solvent Extraction System through Regulation of Fe3+ Coordination

Lithium is becoming increasingly important due to its essential role in lithium-ion batteries. Over 70% of the global lithium resources are found in salt lake brines, where lithium is always accomp...

Lithium isotope separation using 4′-acetylbenzo-15-crown-5 and 1-butyl-3-methylimidazolium bis[(trifluoromethyl) sulfonyl] imide in the synergistic extraction system

A novel synergistic extraction system was studied for the separation of lithium isotopes using lithium salts solution as aqueous phase and dichloromethane containing 4′-acetylbenzo-15-crown-5 and [BMIm][NTf2] as organic phase with solvent extraction method. The key factors such as anions of lithium salts, concentrations of LiNTf2, initial pH values of aqueous phase, solvents, volume ratio of dichloromethane and [BMIm][NTf2] were investigated in this study. Results showed that the maximum extraction rate of lithium was 68.36% and the maximum single stage separation factor of 6Li and 7Li was 1.056 ± 0.002. The formed complex in organic phase was studied by the slope analysis method, which indicated that the complex was composed of Li-ion and 4′-actylbenzo-15-crown-5 by 1:1. The thermodynamic parameters of the 6Li and 7Li exchange reaction were calculated by data obtained on temperature during experiments, which explained that the exchange behavior of 6Li and 7Li in this system was a spontaneous exothermic reaction. In addition, this system was able to efficiently separate lithium isotopes at lower temperature.

Synergistic Solvent Extraction Is Driven by Entropy.

In solvent extraction, the self-assembly of amphiphilic molecules into an organized structure is the phenomenon responsible for the transfer of the metal ion from the aqueous phase to the organic solvent. Despite their significance for chemical engineering and separation science, the forces driving the solute transfer are not fully understood. Instead of assuming the simple complexation reaction with predefined stoichiometry, we model synergistic extraction systems by a colloidal approach that explicitly takes into account the self-assembly resulting from the amphiphilic nature of the extractants. Contrary to the current paradigm of simple stoichiometry behind liquid-liquid extraction, there is a severe polydispersity of aggregates completely different in compositions, but similar in the free energy. This variety of structures on the nanoscale is responsible for the synergistic transfer of ions to the organic phase. Synergy can be understood as a reciprocal effect of chelation: it enhances extraction because it increases the configurational entropy of an extracted ion. The global overview of the complex nature of a synergistic mixture shows different regimes in self-assembly, and thus in the extraction efficiency, which can be tuned with respect to the green chemistry aspect.

Selective recovery of Rhenium from industrial leach solutions by synergistic solvent extraction

In our previous work, the selective precipitation of rhenium from an acidic washing solution present in the copper smelting process was studied. The precipitate formed is a polymetallic sulfide that contains rhenium, copper, arsenic, and bismuth. To recover rhenium from the precipitate, the separation of perrhenate ions from industrial leach solutions using synergistic solvent extraction was investigated. For the synergistic extraction system of Alamine 336 and TBP, Alamine 336 is the primary compound that combines with the anions in the leach solution. The solubility of the extraction complex in the organic phase is enhanced by TBP bonding with the neutral complex. For the extraction of perrhenate ion from the chloridizing leach solution, the difference in the distribution coefficient of rhenium and bismuth is small due to the formation of bismuth polychloride complex ion in aqueous solution. For the acidic leach solution using sulfuric acid and ammonia persulfate, the separation percentage of perrhenate ion is more than 99.90 wt% using four-stage countercurrent extraction. This is because the bismuth and arsenic in the leach solution forms an insoluble compound (BiO)2SO4 and arsenic acid. The loaded organic phase is stripped by a 4 mol/L ammonium solution, recovering 98.78% Re. The content of arsenic, copper, bismuth, and lead in the ammonia perrhenate formed from the evaporation and crystallization process using the stripping liquor is less than 0.5 mg/kg and 1.0 mg/kg, respectively.

A novel synergistic extraction system for the recovery of scandium (III) by Cyanex272 and Cyanex923 in sulfuric acid medium

The synergistic extraction of scandium(III) with a mixture of Cyanex272 and Cyanex923 in sulfuric acid medium has been investigated in this study. At low H2SO4 concentration, the mixture of Cyanex272 and Cyanex923 exhibited an obvious synergistic extraction for Sc(III). When the concentration of H2SO4 was 0.10 mol/L and the molar fraction of Cyanex272 was 0.6, the maximal synergistic enhancement coefficient was obtained to be 5.20. What’s more, the synergistic extraction mechanism was discussed and the extracted complex was determined combined with FT-IR characterized result. Besides, the effect of temperature on the extraction of Sc(III) was investigated, and the thermodynamic parameters and equilibrium constants of extraction reaction have been calculated. In the meanwhile, the synergistic extraction system indicated of a potential practical application value for the recovery of Sc(III) from the sulfuric acid liquor of nickel laterite ores.