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Studies on the extraction of Co(II) and Ni(II) from aqueous chloride solutions using Primene JMT-Cyanex272 ionic liquid on the extraction of Co(II) and Ni(II) from aqueous chloride extractant
Abstract
An important problem associated with the development of continuous process for the extraction and separation of Co(II) and Ni(II) is the decrease in the pH of the aqueous phase after its equilibration with organic solvent containing cationic extractants such as Cyanex 272, LIX 860, etc. An improvement in the solvent extraction and separation of Co(II) and Ni(II) from neutral chloride solutions is obtained using ionic liquid extractant tertiary alkyl (C16–C22) primary ammonium bis 2,4,4-(trimethylpentyl) phosphinate (HJMT–Cy272) generated by reacting primary amine, Primene®JMT (JMT) and bis(2,4,4-trimethylpentyl)phosphinic acid, Cyanex 272 (Cy272) in the organic phase. The presence of JMT allows to control the pH of the equilibrated aqueous phase during the extractions of Co(II) and Ni(II). This has facilitated the application of continuous counter current liquid–liquid extraction in the given metal extraction system without applying any in-between acid neutralization process. The liquid–liquid extractions were carried out under different experimental conditions such as concentration of JMT and Cy272 in the organic phase, and concentration of metal ions in the aqueous phase. The optimized composition of the organic phase to obtain better recovery and separation of Co(II) and Ni(II) is 10% Cy272 + 10% JMT in D100. The equal percentage of Cy272 and JMT in the organic phase gave minimum change in the pH of the aqueous phase before and after its equilibration. The McCabe-Thiele plot suggested three theoretical stages of counter current operation for obtaining greater than 99% extraction of Co(II) from its 1 g/L solution. For two metal system, four stage counter current extraction was carried out using bench scale mixer–settler equipment which gave > 99% extraction of Co(II) along with 11% of Ni in the organic phase whereas about 89% of Ni(II) with about 0.3% of Co(II) remained in the aqueous phase. The loaded organic phase was treated with 0.02 M EDTA to strip metal ions and the same was used successfully for the second run of the extraction and stripping process.
... Using the five-stage extracted process, the separation factor of Co 2+ from Ni 2+ (β Co/Ni ) could be reached 9.5 × 10 3 using the new organic extractant of di-decylphosphinic acid [12]. About >99% of Co 2+ and 11% of Ni 2+ were extracted using the extractant of primene JMT-Cyanex 272 with the process of four-stage counter extraction [13], and the efficient separation of the two metal ions was achieved based on this process. In addition, extractants of MEXTRAL 507P [14], INET-3 [14], and PC88A [15] were also used for the separation of Co 2+ from Ni 2+ . ...
... The changing shift of hydrogen on the -NH 3 for synthesized ionic liquid resulted from the formation of new bonds in the ionic liquid. 13 ...
... The experimental results indicate that Equation (5) can better predict the β Co/Ni for single-stage extraction of Co 2+ from Ni 2+ . With the optimized single-stage extraction conditions, the separation factors of Co 2+ from Ni 2+ using Cyphos IL 104 [4], Cyanex 301 [39], Primene JMT-Cyanex 272 [13], ...
The purpose of this study was to optimize the extraction conditions for separating Co2+ from Ni2+ using N-butylamine phosphinate ionic liquid of [C4H9NH3][Cyanex 272]. A Box–Behnken design of response surface methodology was used to analyze the effects of the initial pH, extraction time, and extraction temperature on the separation factor of Co2+ from sulfuric acid solution containing Ni2+. The concentrations of Co2+ and Ni2+ in an aqueous solution were determined using inductively coupled plasma-optical emission spectrometry. The optimized extraction conditions were as follows: an initial pH of 3.7, an extraction time of 55.8 min, and an extraction temperature of 330.4 K. The separation factor of Co2+ from Ni2+ under optimized extraction conditions was 66.1, which was very close to the predicted value of 67.2, and the error was 1.7%. The equation for single-stage extraction with high reliability can be used for optimizing the multi-stage extraction process of Co2+ from Ni2+. The stoichiometry of chemical reaction for ion-exchange extraction was also investigated using the slope method.
... Solvent extraction has been widely used for the separation and purication of metals from spent LIBs. 17,18 However, there are two technical challenges in cobalt extraction. First, the co-existence of small amounts of iron, magnesium, manganese, and nickel in the spent LIBs is prone to have them extracted with cobalt, thereby decreasing separation efficiency. ...
... The other issue is that both cobalt and nickel ions exhibit similar physico-chemical properties in aqueous solution which make it difficult to separate and purify cobalt from mixtures containing nickel. [18][19][20] For example, Coll et al. 18 used ionic liquid HJMT + -Cy272 (tertiary alkyl (C16-C22) primary ammonium bis 2,4,4-(trimethylpentyl) phosphinate) to extract cobalt with 99% Co(II) recovered from the organic phase; however, 11% Ni(II) was also found in the recovered extracts. It has been reported that organophosphorus extractants (e.g., Cyanex272, D2EHPA or P204, and P507) were employed in the extractive separation of cobalt and nickel from aqueous sulphate media. ...
... The other issue is that both cobalt and nickel ions exhibit similar physico-chemical properties in aqueous solution which make it difficult to separate and purify cobalt from mixtures containing nickel. [18][19][20] For example, Coll et al. 18 used ionic liquid HJMT + -Cy272 (tertiary alkyl (C16-C22) primary ammonium bis 2,4,4-(trimethylpentyl) phosphinate) to extract cobalt with 99% Co(II) recovered from the organic phase; however, 11% Ni(II) was also found in the recovered extracts. It has been reported that organophosphorus extractants (e.g., Cyanex272, D2EHPA or P204, and P507) were employed in the extractive separation of cobalt and nickel from aqueous sulphate media. ...
Spent lithium batteries contain valuable metals such as cobalt, copper, nickel, lithium, etc. After pretreatment and recovery of copper, only cobalt, nickel and lithium were left in the acid solution. Since the chemical properties of cobalt and nickel are similar, separation of cobalt from a solution containing nickel is technically challenging. In this study, Co(ii) was separated from Ni(ii) by chelating Co(ii) with chlorine ions, Co(ii) was then extracted from the aforementioned chelating complexes by methyltrioctylammonium chloride (MTOAC). The effects of concentrations of chlorine ions in the aqueous phase ([Cl-]aq), MTOAC concentrations in organic phase ([MTOAC]org), ratios of organic phase to aqueous phase (O/A), and the initial aqueous pH on cobalt separation were studied. The results showed that [Cl-]aq had a significant impact on cobalt extraction efficiency with cobalt extraction efficiency increasing rapidly with the increase in [Cl-]aq. The effect of initial pH on cobalt extraction efficiency was not significant when it varied from 1 to 6. Under the condition of [Cl-]aq = 5.5 M, [MTOAC]org = 1.3 M, O/A = 1.5, and pH = 1.0, cobalt extraction efficiency reached the maximum of 98.23%, and nickel loss rate was only 0.86%. The stripping rate of cobalt from Co(ii)-MTOAC complexes using diluted hydrochloric acid was 99.95%. By XRD and XRF analysis, the recovered cobalt was in the form of cobalt chloride with the purity of cobalt produced reaching 97.7%. The mode of cobalt extraction was verified to be limited by chemical reaction and the kinetic equation for cobalt extraction was determined to be: R (Co) = 4.7 × 10-3[MTOAC](org) 1.85[Co](aq) 1.25.
... Considering sulfuric leaching liquors and waste solutions of nickel and cobalt, several commercial extractants have been proposed, including D2EHPA (bis(2-ethylhexyl)phosphoric acid) (Sousa et al., 2011), PC88A (2-ethylhexylphosphonic acid mono-2ethylhexyl ester) (Nguyen et al., 2014), LIX 1104SM (hydroxamic acid) (Zhang et al., 2012) and Cyanex 272 (bis(2,4,4trimethylpentyl)phosphinic acid) (Hereijgers et al., 2016;Regel-Rosocka et al., 2016;Tanong et al., 2017), the latter being most commonly used. Mixtures of different extractants, called synergistic mixtures, have also been investigated to improve the efficiency or selectivity of the systems (Coll et al., 2012;Darvishi et al., 2005). In recent years, phosphonium ionic liquids (quaternary phosphonium salts) have been investigated as prospective extractants of Co(II) and Ni(II) mainly from chloride solutions (Cholico-Gonzalez et al., 2015;Rybka and Regel-Rosocka, 2012). ...
... Also, to investigate if a binary mixture of Cyphos IL 101 and Cyanex 272 works as Cyphos IL 104, the following concentrations were used: 0. The mixture of Cyphos IL 101 and Cyanex 272 was investigated to compare its extraction abilities to those of Cyphos IL 104 which consists of phosphonium cation (as in Cyphos IL 101) and bis(2,4,4trimethylpentyl)phosphinate anion (as in Cyanex 272). Coll et al. (2012) claim that a mixture of primary amine (Primene JMT) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) results in formation of ionic liquid, i.e. quaternary ammonium bis(2,4,4trimethylpentyl)phosphinate ([HJMT þ ][A À ]). They have reported almost 100% extraction of Co(II) along with 11% of Ni(II) extraction, with a mixture of 10% Cyanex 272 and 10% Primene JMT in aliphatic diluent. ...
... The application of a mixture of two different extractants is likely to result in, on the one hand, synergic (called also synergetic) or antagonistic effect (Siekierski and Taube, 1961), or on the other hand, in formation of a new IL (Coll et al., 2012). The synergic effect (positive or negative) occurs when the distribution ratio for a mixture of two extractants (D 1,2 ) is greater or smaller than the additive distribution ratio for single extractants (D 1 , D 2 ) (Siekierski and Taube, 1961): ...
This paper presents sustainable hydrometallurgical recovery of Co(II)from wastewater, achieved by application of two ionic liquids (Cyphos IL 101 or 104)and an acidic extractant (Cyanex 272). The separation of Co(II)is carried out from model aqueous chloride and sulfate solutions, as well as from a real waste sulfate solution containing also Ni(II). The extractants were investigated both as single carriers and as synergic mixtures, the latter giving no positive synergistic effect. Cyanex 272 does not allow Co(II)to be transferred from chloride solutions effectively, while extraction from sulfate mixtures reaches totally up to 100% after two stages. Cyphos IL 101 does not give satisfactory results of Co(II)recovery from sulfate solutions, while both Co(II)and Ni(II)are transferred efficiently from chloride ones. Stripping of Co(II)from the loaded organic phases with 1 M H 2 SO 4 is very efficient (95–100%), regardless of the type of extractant (Cyanex 272 or Cyphos IL 104)and its concentration. Application of 1 M H 2 SO 4 allows Co(II)to be recovered from the loaded organic phase (up to 100%)in one stage of stripping and to be enriched even three-to fivefold relative to that in the feed. It also allows the organic phase to be reused for further extractions. Theoretical considerations of economic feasibility of the process proposed indicated that the value of cobalt in solutions after proposed steps increases from 0.32 USD/dm ³ (after two stages of extraction)to 1.42 USD/dm ³ after stripping. The major novelty of this work is the design of hydrometallurgical recovery of Co(II)from real sulfate wastewater in the presence of Ni(II), which permits sustainable processing of waste, recycling and recovery of critical element and also regeneration and reuse of organic chemicals applied for extraction.
... The recommended limit concentrations were set in the guidelines for drinking water as 0.01 mg L −1 and 0.07 mg L −1 for Pb(II) and Ni(II), respectively [2]. The common methods used for the removal of these metals are chemical precipitation [3,4], electrochemical treatment [5,6], solvent extraction [7], membrane technology [8,9], ion-exchange [10,11], and 2 of 18 sorption [12][13][14][15]. According to Demey et al. [16], all these techniques have intrinsic operation shortcomings; e.g., membrane technology and electrochemical treatment require high energy consumption, which is not cost-effective for high volumes of contaminated water; chemical precipitation involves the disposal and treatment of toxic sludge, whereas solvent extraction produces a secondary effluent due to the use of large amounts of organic solvents. ...
... The impregnation of resins was proposed as a technological alternative to a direct solvent extraction technique. Layered silicate materials have been used as supports for impregnation with efficient solvents [7]; the layered crystalline polysilicates are mainly composed of tetrahedral SiO 4 , they usually exhibit a high metal uptake and their manufacturing does not require difficult steps. In recent years, several researchers have studied the adsorption of organic pollutants on modified and unmodified layered silicate [21,22]. ...
A new composite material based on alginate and magadiite/Di-(2-ethylhexyl) phosphoric acid (CAM-D2EHPA) was successfully prepared by previous impregnation of layered magadiite with D2EHPA extractant, and then immobilized into the alginate matrix. Air dried beads of CAM-D2EHPA were characterized by FTIR and SEM-EDX techniques. The sorbent was used for the separation of lead and nickel from nitrate solutions; the main parameters of sorption such as contact time, pH of the solution, and initial metal concentration were studied. The beads recovered 94% of Pb(II) and 65% of Ni(II) at pH 4 from dilute solutions containing 10 mg L −1 of metal (sorbent dosage, S.D. 1 g L −1). The equilibrium data gave a better fit using the Langmuir model, and kinetic profiles were fitted using a pseudo-second order rate equation. The maximum sorption capacities obtained (at pH 4) were 197 mg g −1 and 44 mg g −1 for lead and nickel, respectively. The regeneration of the sorbent was efficiently carried out with a dilute solution of HNO 3 (0.5 M). The composite material was reused in 10 sorption-elution cycles with no significant differences on sorption uptake. A study with synthetic effluents containing an equimolar concentration of both metals indicated a better selectivity towards lead ions.
... The separation of Th(IV) from several rare earths (III) such as La, Ce, Nd, Gd and Er was investigated using N1923/[C 8 mim][PF 6 ] IL by Zuo et al. (2008). A four-stage counter current extraction process was carried out by Coll et al. using a bench scale mixer-settler to separate Co(II) and Ni(II) by 20% of JMTÁCy272 IL (Coll et al., 2012). Although the technique used was not SX, García-Díaz et al. investigated the In(III) transport using RNH 3 + HSO 4 À IL by hollow fiber strip dispersion (García-Díaz et al., 2017). ...
... A procedure similar to the reported by Coll et al. was followed to prepare both ionic liquids (Coll et al., 2012). Stoichiometric quantities of two commercially available extractants P81R and D2EHPA or P81R and Cy572 were mixed in kerosene to prepare both ionic liquids, P81RÁD2EHPA IL and P81RÁCy572 IL, as is shown in Eq. (2). ...
Processing of end-of-life products has become essential in the rare earth elements (REEs) recovery field because the demand for these metals has increased over the last years due to their intensive use in advanced technologies. Fluorescent lamp wastes are considered one of the most interesting end-of-life products for investigation due to their high REEs content, mainly yttrium and europium. As a result, red phosphors (Y2O3:Eu³⁺ – YOX) have been chosen for evaluating their REEs’ recovery potential. The REEs from a YOX reach liquor, coming from a soft leaching process have been precipitated adding oxalic acid and calcined to get the REEs in oxide form. Cyanex 572, D2EHPA and the ionic liquids, Primene 81R·Cyanex 572 IL and Primene 81R·D2EHPA IL, have been chosen to investigate the efficiency of REEs separation in chloride media. Yttrium, europium and cerium have been individually recovered by a four stages cross-flow solvent extraction process using the Primene 81R·D2EHPA IL and the Primene 81R·Cyanex 572 IL as extractants. Ce(III), Eu(III) and Y(III) have been obtained at high purities ≥ 99.9%. 4 mol/L HCl has been used to recover the yttrium and the europium from the organic phases.
... Their discharge concentrations should be reduced to acceptable level limits that it is permitted by the World Health Organization (WHO) and EPA by different chemical or physical methods. [3,4] Chromium has two oxidation states as Cr(III) and Cr(VI). Chromium species are widely used in industrial processes for different purposes with the other heavy metals like Ni, Fe, Cd, and Al, due to especially its highly resistive nature against oxidation. ...
... Stirring speed in LLSX process affects the interfacial behavior of distribution of extracted species between aqueous and the organic phases, emulsion liquid membrane (ELM), [44,45] LLSX [3] . Therefore, as a second study, the stirring speed was investigated. ...
The study was to determine selective removal and recovery of Cr(VI) from acidic media by solvent extraction (SX) using asymmetric imidazolium-based room temperature imidazolium bromide salts (ARTILs) as the extractants. The relevant parameters on the extraction and the stripping of Cr(VI) were investigated to identify optimum conditions. The optimum conditions were determined as equilibration time 5 min., acid concentration and type 0.5 mol/L H2SO4, stirring speed 1200 rpm, extractant concentration and type 0.5 mol/L ARTIL5, phase ratio 2.0 and stripping reagent type and concentration 2.0 mol/L NH3. In optimum conditions, decyl substituted ARTIL was best in extraction process about 99.7% of extraction rate, whereas, moderately hydrophobic pentyl substituted ARTIL was best in stripping process about 70.0% of stripping rate. Also, the optimised process was found as so selective towards Cr(VI) in the presence of the other metal ions with an environmental-friendly liquid-liquid based solvent extraction method.
... In recent years, ionic liquids (ILs) have attracted great interest in the field of metal extraction as an alternative medium to molecular solvents in liquid-liquid extraction processes or as new extractants [13][14][15]. Previous reports have highlighted the potential of room-temperature hydrophobic ionic liquids (RTILs) for the separation of cationic divalent metal ions and the recovery of precious metals in liquid-liquid extraction processes [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. The modularity of ILs allows their design to be adapted to meet the needs of specific applications. ...
A series of salts based on ethyl ester glycine-betaine derivatives, viz tri(n-pentyl)[2-ethoxy-2-oxoethyl]ammonium bromide, have been synthesized. These cations generate hydrophobic ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide (Tf2N−) or dicyanamide (Dca−) anions. These new analogues of glycine-betaine-based ionic liquids (AGB-ILs) were characterized using spectroscopic methods (IR, 1H, and 13C NMR) and elemental analysis. These AGB-ILs were used for the selective separation of Ni(II) and Co(II) in saline media using pure ILs phase or ILs diluted in organic solvent. Interestingly, extraction of Co(II) and Ni(II) in Dca-based AGB-ILs can be enhanced using salts with chaotropic anions such as NaNO3 (E > 90% for Co(II) and E = 85% for Ni(II)). Tf2N−-based ionic liquids do not extract Ni(II) or Co(II) even in NaCl 4M. Dca−-based ILs lead to a quasi-quantitative extraction of Co(II), while extraction of Ni(II) is limited to a few percent (17%) leading to separation factors higher than 100, ensuring a good separation of both metals. Cobalt could be back-extracted from the ionic liquid phase with water or with an aqueous solution of Na2SO4, which limits the release of the AGB cation in aqueous media, thus preserving its integrity. Results obtained by AGB-ILs diluted in organic solvent were comparable to those obtained with the pure AGB-ILs phase, indicating that this strategy can be deployed on systems working continuously out of equilibrium since the extraction mechanisms involve fast equilibria.
... The Ni extraction reaction mechanism is shown in Formula (5). Most studies [21,38,39] use Cyanex272 for the separation of Co and Ni. In this study, Cyanex272 was used for Ni and Li separation for the first time and excellent results were obtained. ...
With the development trend and technological progress of lithium batteries, the battery market is booming, which means that the consumption demand for lithium batteries has increased significantly, and, therefore, a large number of discarded lithium batteries will be generated accordingly. Solvent extraction is a promising approach because it is simple. Solvent extraction is low in time consumption and is easy to industrialize. This paper is focused on the selective recovery of cobalt (Co), nickel (Ni), and manganese (Mn) contained in leachate obtained by digesting a cathodic material from spent lithium batteries with hydrochloric acid. After leaching the cathodic material, Mn was selectively extracted from leachate by using solvent extraction with D2EHPA diluted in kerosene in an optimized condition. Afterward, Co was extracted from the Mn-depleted aqueous phase using Cyanex272 diluted in kerosene. Finally, the raffinate obtained via a stripping reaction with H2SO4 was used in the Ni extraction experiments. Cyanex272 extractant was employed to separate Ni and Li. The process can recover more than 93% of Mn, 90% of Co, and 90% of Ni. The crucial material recovered in the form of sulfuric acid solutions can be purified and returned to the manufacturer for use. This process proposes a complete recycling method by effectively recovering Mn, Co, and Ni with solvent extraction, to contribute to the supply of raw materials and to reduce tensions related to mineral resources for the production of lithium batteries.
... The ILs-based separation and extraction approach is a modern approach that takes the place of volatile organic compounds as an extract [23,24]. The properties of ILs make them predominantly suitable for solvent extraction, including their combustibility and low volatility, thermal stability, wide liquid range, adjustable functional groups, high conductivity, and a wide range of electrochemical applications [25][26][27][28]. The ILs have shown excellent performance in the extraction techniques used in sample preparation and preconcentration of targeted analytes [29][30][31][32][33][34]. ...
Sample preparation is the crucial and most challenging part of analytical chemistry for the speciation of environmental pollutants' traces. Along with the development of the sample preparation methods, the ionic liquid-based microextraction technique plays an important role. Due to the unequivocally unique "green" characteristic of ionic liquids (ILs), they owe their tunable properties, such as highly selective and high reaction efficiency, reusability, and good thermal stability, to present advancements in the sample preparation process. The ionic liquid-based microextraction techniques miniaturize the sample preparation process. Liquid phase microextraction intermediate solvents, desorption solvent extractants, and mediators have been used. They are quoting the benefits and limitations of each method. A few essential sample preparation methods covered the microextraction technique. In this context, miniaturized microextraction methods have been developed. They are generally used for their unlimited positive features, including easy, simple, and environmentally friendly; they also extract inorganic and organic species with low-cost instrumentation. This review advances the sample preparation process using ILs-based liquid phase microextraction as an intermediate solvent, extractant desorption, and mediator solvents.
... In fact, the principal source of exposure for large populations can be found in food (0.1-0.3 mg Ni day −1 ) and to a much lesser extent from drinking water (< 0.02 mg Ni/day) and air (0.0001-0.0007 mg Ni/day) [24]. Generally the methods used to extract metals are chemical precipitation [25,26], electrochemical treatment [27,28], solvent extraction [29], membrane technology [30,31], ion exchange [32,33], and adsorption [34,35]. ...
The development of environmentally friendly, reusable and highly performant adsorbent materials for the removal of heavy metal ions is a big challenge in the field of wastewater treatment. Therefore, in this study, ecofriendly composite materials based on alginates extracted from Sargassum sp (Alg.S) and Turbunaria (Alg.T) and supported on different silica particles were prepared and used as adsorbents for Ni(II) ions removal from aqueous solutions. These composites efficiently extract Ni(II) ions, i.e. the optimal adsorption amount of Ni 2+ reaches 251 mg.g −1 at pH 5 for one composite, surpassing the adsorption capacities of other adsorbents reported so far in the literature. The kinetic data fit well with a pseudo-second order model. Furthermore, the adsorption in a binary system containing both Ni(II) and Pb(II) was also studied. The effect of pH, concentration, and other parameters on the adsorption capacity as well as on kinetics were systematically examined. These results demonstrate that ours composites show great potential as low-cost bio-adsorbents to remove Ni(II) ions from aqueous solutions.
... The SX process is focused on the removal of specific constituents by transferring them from the aqueous phase to an immiscible non-aqueous phase. It is an extensively used method for the recovery and purification of metals because of being simple, selective, and cost efficient with less reaction time and favorable reaction conditions [20]. Among the reagents used in Zn SX, organophosphorus acidbased extractants play a significant role. ...
Zn recovery attempts from a copper-free extreme Acid Mine Drainage with ~ 53 g/L Fe and ~ 2 g/L Zn revealed Fe co-extraction in solvent extraction with 0.9 M D2EHPA or a mixture of 0.72 M D2EHPA and 0.18 M Cyanex 272, and simultaneous precipitation of Fe during zinc sulfide recovery through biogenic sulfide addition. Therefore, alkalinization, solvent extraction with the self-prepared ionic liquid AliCy diluted in kerosene, and combinations of both these methods were studied for the separation of ferric iron (Fe3+) from such water, prior to Zn recovery. The most efficient strategy tested was a solvent extraction cycle with AliCy followed by alkalinization of its aqueous raffinate to pH 3.25 or 3.5. As a result of this approach, ~ 92% of Fe3+ is separated by SX and the remaining is removed by precipitation, with just ~ 12% or ~ 17% Zn losses, respectively. Afterwards, the highest Zn recovery from water resulting from such combination of processes was achieved by precipitation through addition of biogenic sulfide at pH = 3.5. The obtained precipitates are nanoparticles of Wurzite and Sphalerite (ZnS) of sizes between 2 to 22 nm agglomerated into larger structures. This work shows for the first time the potential of AliCy to separate Fe3+ from acidic multimetallic solutions, a known contaminant of several metal recovery processes.
... A number of cobalt extracting agents are known, such as Cyanex 272 (bis(2,4,4-trimethylpentyl)phosphinic acid) (Stefaniak et al., 2020), di(2ethylhexyl)phosphoric acid (D2EHPA/DEHPA), tricaprylylmethylammonium chloride/trioctylmethylammonium chloride (Aliquat 336) (Kang et al. 2010;Swain et al. 2010;Cheng et al., 2019;Alvial-Hein et al. 2021), etc. Recently, ionic liquids (ILs) have been investigated as an alternative to known extractants used for the separation of many metals from aqueous solutions such as Co(II) and Ni(II) (Rybka and Regel-Rosocka et al., 2012;Coll et al. 2012;Cholico-Gonzalez et al., 2015;Turgut et al. 2017;Diabate et al. 2018;Janiszewska et al., 2019). Task specific ionic liquids (TSILs) with coordinating anions are of particular importance. ...
... Decades of research and development studies on solvent extraction of nickel, cobalt and manganese from different ore types have demonstrated it as one of the most efficient technologies in selectively extracting the metal of interest from the complex matrices using suitable organic or extracting impurities from solution (Crundwell et al., 2011) and has found interest because of its fast kinetics, cost efficiency and high selectivity for metals resulting in high purity products though the environmental issues still exist (Coll et al., 2012). Further complications due to co-existence of cobalt and nickel along with some other metals have been tackled, and from the long list of acidic, basic and ionic liquid based solvents tested, Cyanex 272 is recommended to separate cobalt and nickel after a manganese removal stage using D2EHPA . ...
Given the vast resources of battery materials in Southern Africa, Mintek is undertaking battery materials research across a number of disciplines including hydrometallurgy, pyrometallurgy, advanced materials, mining and mineral economics. In a region with a large extractive metallurgy industry, there is potential for Southern Africa to be a significant player in the battery materials value chain towards energy storage. Utilisation of secondary resources for the recovery of battery materials is also explored. The paper provides a summary of the battery materials-based research projects at Mintek.
... The most commonly used modifiers are long-chain alcohols (tridecanol) and esters [14]. Although solvent extraction is a mature and widely used technology with numerous advantages such as low operational costs, the use of organic solvents and the extraction of molecules in large quantities contribute to the environmental impact of the process, due to their volatility, types of hydrocarbon chains, etc. [15,16]. The use of organophosphate extracting molecules (and hydrocarbon solvents to a lesser degree) for the processing of rare earth minerals has been shown to have a great impact on many environmental aspects (eutrophication, acidification, climate change, land use, ecotoxicity, ozone, etc.) [17]. ...
In recent years, the linear economic model and global warming have shown that it is necessary to move toward a circular economic model. In this scenario, the recycling of waste electrical and electronic equipment (WEEE) with green processes is one of the pending tasks; thus, in the present review, advances in the solid–liquid and liquid–liquid extraction processes, processes among the most important for the recovery of metals from ores or WEEE, with green solvents such as deep eutectic solvents (DES) are presented and analyzed, identifying the present and future challenges. To date, most articles focused on one of the processes, be it solid–liquid or liquid–liquid extraction, while few reports included the entire hydrometallurgical process, which could be due to heterogeneity of the WEEE, a characteristic that influences determining the leaching kinetic and the leaching mechanisms. A deeper understanding of the phenomenon would help improve this process and the next stage of liquid–liquid extraction. This also leads to the fact that, at the liquid–liquid extraction stage, most articles considered synthetic pregnant leach solutions to evaluate each of the variables, whereas the stripping of the ions and the recycling of the DESs in continuous processes is a challenge that should be addressed in future work. From the analysis, for WEEE leaching, it was identified that acid DESs are those achieving the best extraction percentages in the leaching of copper, lithium, and cobalt, among others, where the most studied hydrogen bond acceptor (HBA) is choline chloride with an acid (e.g., citric or lactic acid) as the hydrogen bond donor (HBD). For the liquid–liquid extraction of ions is a greater variety of HBAs (e.g., lidocaine, trioctylphosphine oxide and triphenyl phosphate) and HBDs (e.g., decanoic acid, thenoyltrifluoroacetone, and benzoyltrifluoroacetone) used; however, studies on the extraction of cobalt, lithium, copper, and nickel stand out, where the pH and temperature parameters have great influence.
... It has several advantages over the other techniques used in the separation or removal of metals. The technique is less time consuming with low operational cost, provides high selectivity for metals resulting in high purity products (Coll et al., 2012;Mahandra et al., 2017). It can easily be scaled up from bench level to pilot plant operations. ...
The significant development in advanced technologies such as lithium-ion batteries has increased the demand of cobalt and nickel. As a result, continuous supply from primary resources leads cobalt to the critical stage and also affects nickel resources extensively. The presence of limited resources can lead to break in the chain of supply of these metals on demand. Therefore, it is necessary to recycle cobalt and nickel from secondary resources in order to continue the chain of demand and supply. This review provides a detail on solvent extraction processes developed for the separation and recovery of cobalt and nickel from secondary resources in the last decade. The study illustrates applicability of different type of extractants to provide better separation and recovery of said metals from potential wastes originated from different sources. The fundamentals of solvent extraction along with mechanisms of different class of extractants involved in the recycling of metals have been discussed in detail.
... Kerosene, toluene and chloroform are examples of solvents that are usually used to reduce the viscosity of ILs [95]. Coll [102]. They have investigated kerosene (a mixture of alkanes), Solvesso 200 (a mixture of alkyl (C3-C6)-benzenes), and Exxon D100 (cyclo paraffinic solvent) as diluent. ...
Microfluidic technology has attracted great interest across industry and academia. Its engineering characteristics, through miniaturization, can enhance mass- and heat transfer rates together with allowing operation at high concentrations. Combining this technology with a green designer solvent is one of the most recent advances in separation processes. Ionic liquids have negligible volatility and flammability and have an exceptionally large chemical diversity space, which these days can be better utilised through solvent modelling. Ionic liquids have been demonstrated to increase the efficiency and selectivity of extraction by orders of magnitude.
Different types of microfluidic devices have been designed until now, and among those, the segmented flow with alternate regular slugs is the most prominent. Helical coiling can further intensify the internal recirculation by convection, which is the motor of the advanced mass transfer. This is done by liberating Dean forces. A device that leverages such mass transfer intensification in the best possible way is the Coiled flow inverter (CFI) [1]. The coil periodicity is just 4 turnings, and then the winding direction is inversed, e.g. changed from clockwise to counter-clockwise, and this is repeated multiple times. The CFI extraction performance is typically much better than for a straight and a non-inverted helical capillary.
Separation of metals using liquid–liquid extraction methodology is an important research subject of large economical relevance. The common types of equipment in metal extraction have some disadvantages such as long mixing time and huge plant footprint for the coalescence of the multi-phase, which might take very long due to emulsion formation. In this regard, microfluidic devices and ionic liquids provide an alternative as more compact, more efficient, and faster technology. This review shall help researchers to understand the recent improvement in metal extraction processes, and what the addition of disruptive technology can add to an industrial transformation.
... At the same time, the loss rates of Ni and Co were 13.9% and 15.9% in the precipitation process based on the AAS measurement. The lost Ni and Co in the precipitation could be further recovered through other techniques such as phase extraction, precipitation, and ionic exchange [42,43]. In addition, NaCl could be recovered by vaporizing the solution after all transition metal ions were precipitated. ...
The increasing demand for lithium-ion batteries (LIBs) has resulted in raising the price of cobalt (Co) and nickel (Ni), which are key components of the cathode materials of LIBs and their deposits in the earth’s crust are limited. This paper aims to recover Co and Ni from hard alloy scraps (HASs) containing a high concentration of Co and Ni for preparing Li(Ni1−x−yCoxMny)O2 [e.g., Li(Ni1/3Co1/3Mn1/3)O2 (NCM-111) and Li(Ni0.6Co0.2Mn0.2)O2 (NCM-622)] cathodes. Without separating Ni and Co through a solvent extraction process, the Co and Ni can be co-precipitated to directly synthesize (Ni1−x−yCoxMny)(OH)2 precursors. In this way, the production costs of NCM-111 and NCM-622 can be reduced by 4538 and 8126 dollars per ton, respectively. The obtained NCM-111 and NCM-622 exhibit initial discharge capacities of 158.1 mAh g−1 and 158.5 mAh g−1, respectively, and their capacity retention rates are 86.8% (NCM-111) and 85.6% (NCM-622) after 100 cycles. Thus, the combined acid leaching and co-precipitation can be used for valorizing HASs as well as other types of waste Ni- and Co-containing waste alloys for the synthesis of NCMs for LIBs. Schematic illustration of the preparation of NCM materials from HASs.
... Several chelating agents can be immobilized on silica in order to improve its selectivity. Cyanex 272 is an effective extractant for purification and separation of several heavy metals (Salgado et al. 2003; Bari et al. 2009;Coll et al. 2012) and rare earth elements (Liao et al. 2010;Wang et al. 2011Wang et al. , 2012 due to its excellent chemical stability and low solubility in water. These silica impregnated particles (microns order) are not suitable for wastewater treatment in large-scale process. ...
Mesoporous silica impregnate with Cyanex 272 (bis/2,4,4-trimethylpentyl/phosphinic acid) extractant was immobilized into an alginate matrix to obtain a composite sorbent easy to use and applicable in fixed-bed column continuous systems. The sorption efficiency of this material was tested for the recovery of Eu(III) ions from aqueous solutions in batch and continuous mode. The competition among rare earths ions (europium, lanthanum, and lutetium) and among rare earths and calcium or sodium ions was investigated. High calcium concentrations strongly reduce the sorption capacity of the alginate matrix that composes the hybrid material and the Cyanex 272 impregnated into silica powder improves the rare earths’ sorption performance in this calcium charged media. The experimental breakthrough curves obtained were satisfactory fitted by Thomas model.
... 5 Extraction by solvents as a final stage to separate the cobalt selectively and with high yields is also used. Organic reagents such as Versatic 10 and LIX63, 6 Cyanex, 7,8 D2EHPA and LIX63, 9,10 Cyanex 272−Cyphos IL 101, 11,12 PRIMENE JMT-Cyanex 272, 13 mixture of PRIMENE JMT-Versatic 10, 14 and extractants derived from D2EHPA 15 have been studied. However, the volatility and flammability of traditional organic solvents usually represent technical problems and risks to the environment and human health. ...
The application of phosphonium-based ionic liquids (ILs) on the selective extraction of cobalt is presented. The extraction mechanism is established, and different parameters of the process are evaluated. It has been found that it is possible to extract cobalt from aqueous solutions in sulfate media, with the addition of sodium chloride, using phosphonium ILs. The cobalt extraction was selective with respect to nickel and strongly dependent on the chloride concentration in the aqueous solution. The cobalt extraction is given by an anion exchange mechanism through an endothermic process. Cobalt extractions greater than 98% were obtained using the proposed methods. Cobalt stripping from the loaded IL phase using water was proved. Therefore, an alternative extraction process to traditional organic solvents is proposed. This alternative has additional advantages such as easy handling, lower costs in reagents and equipment, and risk reduction.
... The main technologies for removal of heavy metals from wastewater include adsorption, ion-exchange, solvent extraction, membrane technology, electrostatic interaction, and chemical precipitation (Bl€ ocher et al., 2003;Chen, 2004;Coll et al., 2012;Edebali and Pehlivan, 2016;Wan et al., 2018;Yang et al., 2019;Zou et al., 2019). The applications of these technologies in wastewater treatment are often hindered by problems such as expensive material, high running cost, secondary pollution, low efficiency, etc. (Rangel-Mendez et al., 2009;Fu and Wang, 2011). ...
A simple foaming method was applied to fabricate urea formaldehyde (UF) microspheres with cross-linked porous structures for environmental remediation of heavy metals. The specific surface area and average pore radius of the resultant foamed UF microspheres were 11-29 m2/g and 11-25 nm, respectively, which increased with the increasing molar ratio of formaldehyde to urea. All the foamed UF microspheres showed good removal of heavy metals ions (Pb(II), Cu(II), and Cd(II)) in both single- and mixed-metal solutions. Further investigations of Pb(II) adsorption on a selected UF microspheres showed fast kinetics and relatively high adsorption capacity (21.5 mg/g), which can be attributed to the mesoporous structure and abundance of oxygen surface functional groups of the microspheres. Both experimental and model results showed that chelation or complexation interactions between Pb(II) and the surface functional groups were responsible to the strong adsorption of the heavy metal ions on the microspheres. Hydrochloric acid (0.05 M) successfully desorbed Pb(II) from the post-adsorption microspheres for multiple times and the regenerated microspheres showed high Pb(II) removal rates (>96%) in five adsorption-desorption cycles. With many promising advantages, foamed UF microspheres show great potential as a wastewater treatment agent for heavy metal removal.
... Therefore, the simultaneous removal of heavy metal and antibiotic from contaminated environments has become a high priority. To date significant research already has been conducted on the efficient treatment of contaminated wastewater, using various techniques including ionexchange , solvent extraction (Coll et al., 2012), chemical precipitation (Yan et al., 2010), Fenton oxidation (Ioannou-Ttofa et al., 2019) and membrane processes (Gao et al., 2014), where all of these methods were effective to some degree in removing both heavy metals and antibiotics. However, most of these methods suffered from a combination of high operating and infrastructure costs as well as complex processes, which made them generally unsuitable for most developing countries. ...
Most environmental contaminants exist as a complex mixture of both metallic and organic pollutants and it is thus often a major challenge to remove both components simultaneously. In this paper, due to its low cost and environmentally friendliness, iron nanoparticles (Fe NPs) were successfully prepared using a one-step green synthesis for the simultaneous in-situ remediation of mixed contaminants. Specifically Fe NPs were used for the simultaneous removal of Pb(II) and rifampicin. The removal efficiency for Pb(II) and rifampicin were 100% and 91.6%, respectively. To better understand the mechanism of mixed contaminant removal by Fe NPs various characterization methods and the major conditions impacting removal efficiency were examined. It was concluded that (1) polyphenols and caffeine, both ubiquitous in green tea extracts, acted as both reducing and capping agents during the preparation of Fe NPs, reducing the agglomeration of Fe NPs and increasing their stability and reactivity; (2) the removal mechanism of contaminants involved Pb(II) being adsorbed onto the surface of Fe NPs due to the innate strong adsorption of metal ions onto iron oxides, while rifampicin and Pb(II) both interacted positively with the functional groups on the surface of Fe NPs. Overall, this study demonstrated that green synthesis Fe NPs had potential for use as inexpensive and efficient adsorbent for the simultaneous removal of both Pb(II) and rifampicin from wastewater.
... Owing to their negligible vapor pressures and nonflammabilities, ILs are promising alternatives to VOCs [18][19][20]. Therefore, the extraction of metal ions using ILs has been extensively investigated in the field of sustainable separation processes [21][22][23][24], including the solvent extraction of rare earth ions based on functionalized ionic liquids [25,26], removal of lithium from aqueous solutions by two non-fluorinated ionic liquids [27], and partition of Co (II) and Ni (II) using pure phosphonium ionic liquids or ammonium-type ionic liquids [28,29]. Nonetheless, there are only few reports on the use of trin-octylmethylammonium chloride (TOMAC) for the extraction and separation of vanadium from acid leaching solutions. ...
An efficient separation and extraction method for the recovery of V (V) from a sulfuric acid leaching solution of vanadium shale was developed using the ionic liquid tri-n-octylmethylammonium chloride (TOMAC). In this study, the main factors affecting the extraction of vanadium using TOMAC were investigated. Under optimum conditions, including a TOMAC concentration of 20 vol%, initial aqueous phase pH of 1.8, phase ratio (O/A) of 1:10, and extraction time of 2 min, 98.1% of vanadium was separated by a three-stage extraction, while almost no other impurities were extracted. The V (V) present in the scrubbed organic phase could be quantitatively stripped using 1.0 mol/L NaOH. Moreover, the extraction mechanism using TOMAC was analyzed by Fourier transform infrared (FT-IR) spectroscopy as well as the slope method. The obtained results supported the existence of an anion exchange mechanism between the Cl⁻ atoms of TOMAC and H2V10O28⁴⁻ (HV10O28⁵⁻) within the extraction system.
... The possibility to combine different cation/anion pairs to develop new ionic liquids for specific tasks promoted their extensive use in the field of the metal ion separations. [36][37][38][39][40][41][42][43][44][45][46][47][48] This work presents the extraction and separation of cobalt(II) and nickel(II) from sulphate media using the acid-base couple [HJMT + Versatic10 − ] as a tailored extractant. The purpose is to produce an ionic liquid able to make the selective separation of cobalt(II)/nickel (II) from an aqueous sulphate solution using a continuous counter-current extraction process without conditioning the inter-step pHs. ...
This work claims the use of the mixture of Primene®JMT-Versatic 10 [HJMT⁺·Versatic⁻] IL diluted in Kerosene as an extractant for cobalt/nickel separation from sulphate media by solvent extraction technique, its application on a continuous counter-current device is possible because the presence of Primene®JMT in the organic phase allows us to maintain the pH of the equilibrated aqueous phase at an almost stable value. The solvent extraction of cobalt and nickel ions is studied as a function of the extractant concentration in the organic phase and the concentration of both metals. By constructing the McCabe–Thiele diagram, we found that four steps are necessary to separate the cobalt(II) from the nickel(II) in sulphate media. A simulated continuous counter-current experiment corroborated the McCabe–Thiele predictions, obtaining a raffinate containing 83% of the inlet nickel with a purity of 99.9%, working with an A:O ratio 1:2.
... Thus, it is necessary to develop the effective methods for elimination of these toxic metals from water systems. Nowadays, many methods have been applied for the removal of toxic metals containing electrocoagulation [15], evaporation [16], membrane process [7], flotation [17], solvent extraction [18] and precipitation [19]. The methods mentioned above usually need high energy consumption leading to the high costs for high volumes of polluted water and also are not effective at very dilute solutions [20]. ...
The chitosan/cerium oxide/iron oxide (chitosan/CeO 2 /Fe 3 O 4 ) nano-composite adsorbent was synthesized for the removal of Cr(VI) and Co(II) ions from aqueous solution in a batch system. The adsorbents were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller and X-ray diffraction analyses. The effect of CeO 2 and Fe 3 O 4 contents on the adsorption capacity was studied. The adsorption capacity was significantly increased after modification of adsorbents with CeO 2 and Fe 3 O 4 nanoparticles. Furthermore, the simultaneous effects of four independent variables including initial metal concentration, temperature, solution pH and adsorbent dosage were studied using response surface methodology. The optimum adsorption capacity was found to be 208.18 and 172.92 mg/g for Cr(VI) and Co(II) ions, respectively, under the following adsorption conditions: initial concentration of 200 mg/L, temperature of 20°C, adsorbent dosage of 10 mg, initial pH 5.54 for Cr(VI) and pH 9.00 for Co(II) ions. The validation tests showed that the predicted model agreed well with the adsorption experimental data. The isotherm and kinetic data were precisely described by the Langmuir and pseudo-second-order models, respectively. The maximum adsorption capacity obtained from Langmuir isotherm were 316.10 and 263.57 mg/g for Cr(VI) and Co(II) ions, respectively. Thermodynamic investigation showed that the nature of adsorption process was exothermic and spontaneous.
... Among the methods for effluents depollution, biosorption has many advantages for removing dilute metal ions face to flocculation-coagulation [9,10] and solvent extraction [11,12] techniques: the simplicity of the process and the easy availability of the sorbents, involve lower operation costs of the system. Moreover, the thermal pre-conditioning of the biomass is crucial for achieving high performances, since the presence of reactive groups is essential to achieve this goal [13]. ...
Two low-cost renewable poplar-based materials were manufactured in this work for energy production and as sorbents for lead and terbium removal from aqueous effluents. Torrefaction was used as a pretreatment process for conditioning the raw biomass. Two different operating conditions were used in the multiple-hearth furnace of the torrefaction pilot-plant: i) 250 °C ; ii) 280 °C, with residence times of 75 min and 60 min, respectively. The raw and torrefied biomasses have been characterized using SEM-EDX, FTIR, TGA, XRD and elemental analyses (C, H, N, S, O); an increase of the torrefaction severity, results in an increase of the carbon/oxygen ratio and in a greater mass loss (21% at 250 °C, and 53% at 280 °C). The torrefaction had a positive impact on the sorption of metals, it allowed the increase of lignin content of the manufactured materials, and it allowed the storage of the sorbents for longer time with reduced moisture content. The equilibrium studies were performed in batch system and the experimental data were described with the Sips equation. The maximum sorption capacity was found as 30 mg g-1 for lead and 9.4 mg g-1 for terbium (at pH 4). The kinetic profiles were fitted using the pseudo-second order rate equation. The regeneration of the sorbent was demonstrated by three sorption-desorption cycles using dilute HNO3 solution (0.1 M) as eluent for metal recovery.
... These heavy metal ions have high poisonousness and lead to bioaccumulation through the food chain Sirk et al. 2009). Various purification methods such as precipitation (Becker et al. 2012), electrochemical treatment (Mirbagheri and Hosseini 2005), membrane process (Kim et al. 2017), solvent extraction (Coll et al. 2012), ion exchange (Bai and Bartkiewicz 2009), flotation (Polat and Erdogan 2007), and adsorption processes (Prakash et al. 2016;Prakash et al. 2013;Prakash et al. 2012;Tehrani et al. 2017) have been developed for wastewater treatment. Among these technologies, adsorption is preferred for heavy metal removal at low concentration because of its simplicity, high efficiency, and cost-effectiveness (Petrella et al. 2018). ...
A novel chitosan/ceria/iron oxide (CS/ceria/Fe3O4) nano-composite adsorbent was synthesized for removal of Cr(VI) and Co(II) ions from aqueous systems in a batch system. The adsorbents were characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and Brunauer- Emmett-Teller (BET) analyses. The behavior of swelling kinetics was also studied. The effect of several adsorption parameters including CeO2 and Fe3O4 contents, initial pH, contact time, initial Cr(VI) and Co(II) concentration, and temperature on the adsorption capacity was studied. The double exponential model revealed a better fit with the kinetic data of Cr(VI) and Co(II) ions. The Cr(VI) and Co(II) adsorption process well fitted the Langmuir model. The maximum adsorption capacities estimated from Langmuir isotherm model were 315.4 and 260.6 mg/g for Cr(VI) and Co(II) ions, respectively. Also, thermodynamic parameters were used to distinguish the nature of Cr(VI) and Co(II) adsorption. The reusability of CS/ceria/Fe3O4 nano-composite was evaluated with stripping agents of 0.1 M NaOH and 0.1 M HNO3. Finally, the evaluation of Cr(VI)-Co(II) coexisting system confirmed that the presence of Co(II) ions played an inhibitor role on the Cr(VI) adsorption.
... Hence, before discharging the aqueous metal ion solutions into the environment, it is a vital necessity to remove Cd(II) and Ni(II) ions from industrial wastewater (Elouear et al. 2009;Rad et al. 2014). A number of traditional technologies were applied to eliminate heavy metal ions from water streams containing solvent extraction (Coll et al. 2012), precipitation (Esalah and Husein 2008), membrane (Shih et al. 2018), flotation (Taseidifar et al. 2017), coagulation (Tang et al. 2016), and ion exchange (Bai Responsible editor: Guilherme L. Dotto and Bartkiewicz 2009). However, most of these conventional techniques are ineffective and expensive, especially in eliminating heavy metal ions from very dilute aqueous solutions and need further investigations (Taha et al. 2012). ...
The performance of synthesized cast and electrospun polyvinyl alcohol/chitosan/zinc oxide/aminopropyltriethoxylsilane (PVA/chitosan/ZnO-APTES) nano-adsorbents were compared in removal of Cd(II) and Ni(II) ions from wastewater. The adsorbents were characterized by SEM, BET, FTIR and TGA analyses. Furthermore, the swelling investigations were carried out to study the adsorbent stability in aqueous solution. The effect of several parameters such as contents of ZnO-NH2, contact time, initial Cd(II) and Ni(II) concentration and temperature on the adsorption capacity was investigated in a batch mode. In comparison with cast adsorbent, nanofiber adsorbent indicated the better adsorption performance. The experimental data well fitted the double-exponential kinetic model. In single metal ion system, the maximum adsorption capacity of nanofiber for Cd(II) and Ni(II) ions is estimated to be 1.239 and 0.851 mmol/g, respectively, much higher than qm of cast adsorbent for Cd(II) (0.625 mmol/g) and Ni(II) (0.474 mmol/g) ions. Thermodynamic parameters were investigated to identify the nature of adsorption process. In binary system of Cd(II)-Ni(II) ions, the inhibitory effect of competitive Cd(II) ion on the Ni(II) adsorption was greater than the inhibitory effect of competitive on the Cd(II) adsorption. The selectivity adsorption of both nanofiber and cast adsorbents was in order of Cd(II) > Ni(II).
... The group function of Cyanex 272 is a phosphinic acid. The metals present in aqueous solutions are extracted through a cationic exchange mechanism by the reaction described in Eq. (1) (Coll et al. 2012) ...
This study focused on the selective recovery of zinc (Zn) from a leaching solution emerging from a sulfuric acid leaching process applied to unsorted spent batteries. Precipitation and solvent extraction were investigated. According to the results, solvent extraction using Cyanex 272 allowed for the selective removal of Zn from the solution containing high amounts of metals (∼19.4 g Zn/L, ∼23.4 g Mn/L, ∼3.27 g Cd/L, ∼3.19 g Ni/L, and ∼0.25 g Co/L). According to the results, the solvent extraction process was capable of recovering 97.6% of Zn from this leaching solution under the following conditions: two stages of extraction in the presence of an organic solution made of Cyanex 272 (30%, v/v) and tributylphosphate (TBP - 2%, v/v) in kerosene, pH=2.2, organic/aqueous (O/A) ratio = 2/1, and T=50°C. The Zn present in the organic phase was then stripped using 0.4 M H2SO4 with an O/A ratio fixed at 2/1. This stripping step allowed for the recovery of 81.8% of the Zn initially present in the organic phase. Subsequently, 82.4% of the Zn stripped in the aqueous solution was then electrically deposited after 3 h at pH=2 with a current density fixed at 360 A/m2.
... This was due to theirs characteristics as: zero volatility, good miscibility and solubility of organic and inorganic compounds and low toxicity. It exists as liquid over a wide range of temperatures (Abbott and McKenzie, 2006;Coll et al., 2012;Tian, 2012). Aliquat336 is a commercial ionic liquid, called as Starks's catalyst. ...
The technique of emulsion ionic liquid membrane (EILM) was used as chemical process for Pb(II) recovery, from nitrate medium, using Aliquat336 as ionic liquid carrier. The Tween20 as a dispersive non-ionic surfactant was used for the emulsion formation. The optimization of the extraction and pre-concentration of Pb(II) was determined by optimizing one parameter at the time. So, several experimental parameters as: carrier concentration, surfactant concentration, time and stirring speed of feed phase, initial concentration and pH of feed phase, were studied. The results showed that the lead ions were extracted at 82.61% by Aliquat336 and recovered at 82.16%, in aqueous solution of the nitric acid, from a feed phase of lead(II) nitrate of 207.2 ppm at pH equal to 5.5, in presence of 1% w/w Aliquat336 and 0.5% w/w of Tween20 under 30 min of stirring at 210 rpm. The tests of separation experiments of Pb(II) and Cu(II) were carried on the basis of the optimal conditions of lead (II) recovery. Thus, the separation factor of lead over copper was equal to 1.30, obtained from their equimolar synthetic mixture. Indeed, the recovery of Cu(II) can be advantageous towards of Pb(II) if the molar composition of Cu/Pb in mixture was of 0.65. Response surface methodology (RSM) using Box–Benheken Design (BBD) was used for the statistical study. So, the reduced cubic of the quadratic model showed that the predicted values were in good agreement with those found experimentally and the parameter of ionic liquid concentration has an important individual effect on the response. Therefore, the recovery of Pb(II) can be predicted at 82.14% with the best desirability of the chosen model under our experimental conditions.
... Nickel and cadmium compounds are potentially carcinogenic to humans, being the recommended levels of 0.07 mg L −1 and 0.003 mg L −1 , respectively. Several methodologies have been applied for the removal of heavy metal from waters, such as chemical precipitation [4,5], electrochemical treatment [6,7], membrane technology [8,9], solvent extraction [10], ion-exchange [11,12] and biosorption [13][14][15][16]. All these techniques have intrinsic operation shortcomings, e.g., electrochemical treatment and membrane technology usually require high energy consumption which are not cost-effective for high volumes of contaminated water; solvent extraction produces secondary pollution due to involvement of a large amount of organic solvents (and eventually involves a further processing step for eluent treatment); chemical precipitation includes the disposal and further treatment of toxic sludge [17]. ...
Two sorbents have been synthesized for the efficient removal of heavy metals (e.g., Pb(II), Cu(II), Cd(II), Zn(II) and Ni(II)) from aqueous solutions. Originally, the Alginate/PEI (A-PEI) sorbent containing calcium alginate (as an encapsulating matrix) and polyethylenimine derivatives was manufactured by using internal ionotropic gelation and tested in batch and continuous system. The introduction of Fucus vesiculosus alga improved this material by partially replacing the industrial alginate contained in the biosorbent; it provided a practical one-pot process for faster fabrication, and allowed the manufacturing of a novel environmentally-friendly material (Alginate/Fucus vesiculosus/PEI; AF-PEI). The sorbents have been compared in batch system and characterized using ESEM−EDX and FTIR analyses. The uptake kinetics data were modeled using pseudo-second order rate equation and the sorption isotherms were fitted using the Langmuir, Freundlich and Sips equations. Experimental data were better described with the Sips model and the sorption capacities followed the order: Pb(II) ≈ Cu(II) > Cd(II) ≈ Ni(II) > Zn(II) for A-PEI and Cu(II) > Pb(II) > Zn(II) ≈ Ni(II) > Cd(II) for AF-PEI. Among the synthesized beads, AF-PEI material had the highest sorption capacities for heavy metal removal (1.44 mmol g⁻¹ for Cu(II); 1.09 mmol g⁻¹ for Pb(II); 1.03 mmol g⁻¹ for Ni(II); 1.07 mmol g⁻¹ for Zn(II); 0.87 mmol g⁻¹ for Cd(II) at pH 4). The recycling of the sorbents was tested with 0.1 M HCl/0.05 M CaCl2 solution; the materials had a higher selectivity for Pb(II) and Cu(II), maintaining the removal efficiency over 70% and 40% for these species in five successive sorption-desorption cycles.
... Extraction of cobalt from sulfate or chloride media using various extractants as a single extractant such as Alamine336 (Sayar et al., 2009); Alamine300 (Surucu et al., 2012); Alamine304 (Valverde et al., 2008); Cyanex272 (Coll et al., 2012;Swain et al., 2015) Cyanex302 (Dimitrov et al., 2006;Menoyo and Elizalde, 1997); Cyanex301 (Grigorieva and Fleitlikh, 2013;Padhan and Sarangi, 2014); D2EHPA (Nadimi et al., 2014;Vernekar et al., 2013) and PC88A (Lin et al., 2006) or the mixture of extractants such as carboxylic acid and aliphatic hydroxyoxime (Cheng, 2006); Versatic10 and LIX63 (Cheng et al., 2010;Zhu et al., 2012); Cyanex272 and Cyanex302 (Darvishi et al., 2005); ...
In this study, a pilot plant Oldshue–Rushton extraction column has been proposed to extract and recover cobalt from sulfuric acid leach solution. The effect of D2EHPA and TBP concentration, initial aqueous pH and stripping solvent on the Co(II) extraction was investigated in the batch experiment. The results from batch experiments showed that the D2EHPA/TBP mixed extractant is a suitable choice for cobalt extraction from sulfate solution. In continuous experiments, the effects of variables such as rotor speed, dispersed and continuous phase velocities on holdup, mean drop sizes, extraction and stripping efficiencies were studied. Empirical correlations for prediction of the dispersed phase holdup and mean drop sizes in the literature were compared with the experimental results, and the modified correlations were proposed with reaction condition in the Oldshue–Rushton extraction column. The results of cobalt extraction with D2EHPA/TBP in the extraction column, showed the feasibility of the column for cobalt separation from sulfuric acid leach solution with extraction efficiency of 93% and stripping efficiency of 91.5% at high rotor speed (220 rpm).
... Every day, an enormous amount of heavy metal containing industrial effluents has been released into the natural sources at the end of industrial activities especially in third world countries. The discharge limits of heavy metals at the end of the industrial activities should be held in the acceptable concentration limits according to the boundaries of World Health Organization (WHO) and EPA [4,5]. Therefore, new environmentally friendly, reversible and cheaper removal or recovery processes should be developed and optimised to eliminate or minimise the hazardous effects of the heavy metals on the environment and natural sources. ...
In this study, the relationship between transport performance of Cr(VI) through PVDF-co-HFP based ionic polymer inclusion membranes (IPIM), alkyl chain length of symmetric imidazolium bromide based room temperature ionic liquids (RTILs) and morphological changes of these IPIMs has been comprehensively described. Butyl, hexyl, octyl, and decyl substituted RTILs containing IPIMs were prepared in different compositions and their effectiveness on Cr(VI) transport was experimentally optimised. In optimum conditions, the initial mass transfer coefficient (Jo) value of Cr(VI) was found as 5.0x10⁻⁶ mols⁻¹m⁻², and also, we found that the optimised process is significantly selective for chromium in existence the other heavy metal ions. Morphological and structural characterizations of IPIMs have been performed before and after Cr(VI) transport to illuminate the morphological and the structural changes. Also, the additional plasticizing effect of RTILs as an unusual morphological phenomenon have come forward. In today’s industrialised world, the demand for environmentally friendly processes for removal or recycle of toxic substances by simpler and cheaper ways have been increasing day by day. As a result, our developed and optimised membrane-based process seems to be overcome some Cr(VI) dependent environmental and industrial difficulties.
... In metal recovery and refining, extraction with ILs provides new prospects to exploit low-value metal ores and to recycle metal ions (121,122). A number of studies have been focused on developing effective extractants for SX; however, very few reports can be found in the literature concerning the mixtures of ILs and classic extractants. ...
Solvent extraction is widely employed in a variety of industries for both the upgrading and purification of a range of elements and chemicals. The technology is used in applications as diverse as ore processing, pharmaceuticals, agriculture, industrial chemicals, petrochemicals, the food industry, the purification of base metals, and the refining of precious metals. This review deals with the basics of solvent extraction technique and discusses in detail its applications in several fields focusing on ore processing and recovery of important metals from economic and industrial point of view.
In this study, five novel ionic liquids denoted by [RNH3][Cyanex 272] where R=C4H9, C6H13, C8H17, C10H21, and C12H25 were synthesized in a one-step reaction of straight-chain primary amines and Cyanex 272. The singe-stage extraction performance of [RNH3][Cyanex 272] for the separation of Mn²⁺, Co²⁺, Ni²⁺ and Li⁺ was investigated. Compared with the other [RNH3][Cyanex 272], the [C4H9NH3][Cyanex 272] has good selective extraction and separation of Mn²⁺, Co²⁺, and Ni²⁺ due to the smaller different value between the radius of metal ion and the radius of [C4H9NH3]⁺. Using a three-stage cross flow extraction, the extraction percentages of Mn²⁺, Co²⁺, Ni²⁺, and Li⁺ were about 99.4, 99.1, 14.9 and 0.9 %. The [C4H9NH3][Cyanex 272] is a good extraction agent for co-extraction of Mn²⁺ , Co²⁺, and a part of Ni²⁺ from Li⁺ based on a three-stage cross flow extraction. Diluted sulfuric acid was used to strip the organic phase containing Mn²⁺, Co²⁺, and Ni²⁺, and the aqueous phase containing Mn²⁺, Co²⁺, and Ni²⁺ can be used for the preparation of ternary precursor materials. The precipitation method can be used to prepare Ni(OH)2 and Li2CO3 from an aqueous phase containing Ni²⁺ and Li⁺. The conceptual recycling flow-sheet for Mn²⁺, Co²⁺, Ni²⁺, and Li⁺ from spent ternary lithium batteries was presented on basis of the new extraction agent. The slope method was also used to investigate the mechanism of the extractive reaction of Mn²⁺, Co²⁺, and Ni²⁺ using the [C4H9NH3][Cyanex 272].
With the intensity of resource scarcities and environmental problems, the disposal and recovery of spent lithium-ion batteries, especially recovery of valuable metals, becomes vital. In this work, a method of co-extracting nickel, cobalt, manganese and being separated from lithium by single-stage solvent extraction is proposed. The extraction and separation process of D2EHPA was studied. The effects of extractant concentration, saponification percentage, extraction time and O:A on the extraction efficiency of D2EHPA were systematically studied. Nearly 100% manganese, 94% cobalt and about 90% nickel were co-extracted and separated from lithium using D2EHPA in kerosene by single-stage extraction. The maximum value of separation factors (βNi/Li, βCo/Li and βMn/Li) was 13.03, 23.42 and 1904.24. The mathematical model of extraction of four ions was developed by combination of Levenberg-Marquardt method and Universal Global Optimization method. The proposed extraction model accurately fits the experimental data and helps to predict the extraction efficiency of each metal under the corresponding conditions.
The eventual fading and scrapping of lithium (Li)-ion batteries will result in the formation of a huge urban mine of spent batteries. Hydrometallurgy and further extraction/separation are effective ways in which to recover the valuable metal ions from such batteries. Herein, extraction and recovery of spent lithium cobalt oxide (LiCoO2) battery leach liquors using Cyphos IL-101 is proposed. Based on the optimization of extraction conditions, continuous circulating extraction, and thermodynamic analysis, Cyphos IL-101 effectively extracted cobalt (Co) ions with excellent stability and high extraction capacity (35.25 g/L). The separation factor of Co and Li (βCo/Li) was 102.11 in 0.5 M HCl at 60 °C under the optimal operation condition. Moreover, an increase in temperature increased Co extraction in the spent Li-ion battery leach liquors. The extractants before and after use were characterized using ultraviolet-visible (UV–Vis) absorption spectra, Fourier transform infrared (FTIR) spectra, and nuclear magnetic resonance (NMR) spectra. The extraction mechanism of cobalt ions by Cyphos IL-101 was suggested as that cobalt transferred to the organic phase from the aqueous phase in the form of [CoCl4]²⁻. 90.5% of Co and 86.2% of Li were recovered by precipitation after extraction separation in the forms of cobalt oxalate and lithium carbonate with the purity 87.4% and 74.2%. This suggested method might provide a promising strategy for recycling spent lithium cobalt oxide batteries.
For the ever-growing demand of nickel (Ni) resources in industry, the Ni recovery from the mining residues or waste has received considerable interest. Zinc plant residue contains valuable metals it may be recovered using conventional pyrometallurgical or hydrometallurgical processes. The present communication is focused on the selective recovery of Ni from the real nitric acid leach solution of zinc plant residue by solvent extraction (i.e. 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) as ionic liquid, Di-(2-ethylhexyl) phosphoric acid (D2EHPA) and diphenylthiocarbazone (dithizone)). At first step, leaching of filter cake with the nitric acid solution was examined experimentally and it was observed that nitric acid as a relatively strong oxidant, can adequately dissolve Ni and Zn. After that, Ni and Zn extraction behavior in the leach solution was studied and the influence of pH and extractant concentration were investigated on the extraction of the metals. The results indicated Ni can be effectively separated by controlling the pH values. Moreover, Ni can be selectively separated using dithizone combined with [bmim][PF6] at pH = 5.5 and the separation factor βNi/Zn can reach 2.27×10⁵ in one extraction stage. The extraction mechanism of Ni was investigated using slope analysis and stripping efficiencies 100% have been achieved for Zn and Ni with 2.0 M HNO3. Thus, it can be concluded that the use of [bmim][PF6] as alternatives solvents which have a less significant environmental impact than the usual solvents in terms of emission of vapors is one of the promising approaches for nickel ion extraction from the real leaching solution of zinc plant residue.
For in‐situ resource utilization (ISRU), the cost‐mass conundrum needs to be solved, before any other formidable challenges may be tackled. Technologies may need to be conceptualised from first principals, rather than taking the most advanced technology of today. Using this approach, this paper seeks to provide a think tank about how chemical process intensification can help with technology and business case disruption of ISRU matters, how this might influence Space‐industry start‐ups, and first of all even Earth‐industry transformations. The disruptive technology considered is continuous micro‐flow solvent extraction and, as another disruptive element therein, the use of ionic liquids (instead of conventional organic solvents). The Space business considered is Asteroid mining, as it is probably the most challenging resource site, and the focus is on its last step: the purification of adjacent metals (cobalt versus nickel). The key economic barrier is defined as the reduction of the amount of process water used in the Asteroid mining process. This paper suggests a pathway toward water savings by orders of magnitude, up to the technological limit of best Earth‐process intensification and their physical limits (e.g. of solubility). This is believed to provide a solution to a major economic bottleneck, whilst leaving many technology developments to be achieved before a holistic system and business picture can be given.
For the in situ resource utilization (ISRU) of asteroids, the cost–mass conundrum needs to be solved, and technologies may need to be conceptualised from first principals. By using this approach, this Review seeks to illustrate how chemical process intensification can help with the development of disruptive technologies and business matters, how this might influence space‐industry start‐ups, and even industrial transformations on Earth. The disruptive technology considered is continuous microflow solvent extraction and, as another disruptive element therein, the use of ionic liquids. The space business considered is asteroid mining, as it is probably the most challenging resource site, and the focus is on its last step: the purification of adjacent metals (cobalt versus nickel). The key economic barrier is defined as the reduction in the amount of water used in the asteroid mining process. This Review suggests a pathway toward water savings up to the technological limit of the best Earth‐based processes and their physical limits.
Taguchi’s framework for the design of experiments (DOE)—more specifically, the orthogonal array L4 (2³)—was used to optimize the extraction process of Co(II) statistically. A series of experiments involving the liquid–liquid extraction of cobalt by the ionic liquid extractant Aliquat 336 in a hydrochloric acidic medium were conducted. One experimental parameter was optimized per experiment. The cobalt was extracted (efficiency: 62%) and pre-concentrated (efficiency: 41%) from the loaded organic phase in deionized water (the stripping solution). Application of the McCabe–Thiele method indicated that six theoretical stages were needed to recover 98% of the cobalt. Process optimization was then performed via statistical analysis of the experimental data. Analyses of variance and of means showed that uncontrollable factors (noise) were completely absent from the process, and that only the main effects of the controllable factors A, B, and C—with no factor interactions—contributed to the optimal extraction of the cobalt, which was achieved when A, B, and C were at levels 2, 2, and 1, respectively. In this scenario, the signal-to-noise ratios for A, B, and C were 32, 29, and 26, respectively. Factor A was found to exert the strongest influence on the Co(II) extraction efficiency (50% of the combined influence of the three factors), followed by factors B (28%) and C (22%). Taguchi’s method is a widely accepted approach to DOE, and the application of this approach in this work shows that high-quality products can be produced using ecological green solvents, thus reducing the impact of cobalt production on the environment and ecosystems, which is important given that the cobalt mining industry is expanding globally.
Experiments of extraction and stripping of cobalt(II) were carried out. The liquid–liquid extraction process was considered, in which the organic phase was constituted of Aliquat 336 extractant that is the quaternary ammonium salt, and oleyl alcohol modifier dissolved in dodecane where the aqueous phase contained the metal ion in a concentrated hydrochloric acid solution. The optimization of Co(II) recovery was determined by optimizing one parameter at the time. Therefore, several experimental parameters such as Aliquat 336 concentration, extraction time, hydrochloric acid concentration, and the initial concentration of metal ion were studied. The cobalt(II) ions were extracted at 62.5% and stripped from the metal-loaded organic phase at 41.0% by distilled water as stripping agent. The mass balances were checked for all the studied parameters with an average deviation percentage of 2%. In fact, the McCabe–Thiele showed six theoretical stages for total recovery of cobalt. The separation tests of Co(II) and Ni(II) were carried out on the basis of the optimal conditions of Co(II) recovery. It showed that the nickel ions were slightly extracted (< 10%) whatever the composition of mixture. A Taguchi design with a L4 orthogonal array was used for the statistical study to determine the influence and the contribution percentage of certain experimental parameters on the Co(II) extraction. Analysis of variance and analysis of means showed a total absence of the uncontrollable factors (noise), in which the chosen model has described our extraction process with accuracy. In fact, only the main effects without interaction of controllable factors (A, B, and C) contribute to the optimal extraction of cobalt as follows: A (50.10%), B (28.33%), and C (21.47%) at levels: 2/2/1 with high signals as 32.07, 28.38 and 25.13, respectively.
Present work addresses Co(II) extraction from chloride medium using toluene diluted Cyphos IL 102 as an innovative extractant for the recovery of cobalt. Effect of various parameters has been examined. Co(II) is transferred into the organic phase as [P 66614⁺ ] 2 [CoCl 4²⁻ ] which can be efficiently stripped by 0.05 mol L ⁻¹ HCl. Loading capacity and recyclability have been assessed. Temperature effect confirmed that the extraction of Co(II) is endothermic in nature. Studies were further extended to recover cobalt, manganese and lithium from waste Li-ion batteries containing 2.915 g L ⁻¹ , 0.576 g L ⁻¹ , 3.370 g L ⁻¹ , 0.407 g L ⁻¹ , 0.014 g L ⁻¹ , 0.033 g L ⁻¹ , 0.019 g L ⁻¹ of cobalt, lithium, manganese, nickel, aluminium, iron and copper, respectively. The influence of the concentration of Cyphos IL 102 to extract cobalt from leach liquor has been investigated. The McCabe-Thiele plot suggested two theoretical stages of counter current extraction at A/O 1/1 with Cyphos IL 102 (0.2 mol L ⁻¹ ) for the quantitative extraction of Co(II) with negligible extraction of nickel and lithium. A stripping efficiency of around 99.9% for Co(II) was obtained using 0.05 mol L ⁻¹ HCl in a single stage at O/A 1/1. Cobalt is recovered as cobalt oxide from the loaded organic phase. Manganese and lithium were also recovered from leach liquor as MnO 2 and Li 2 CO 3 using the precipitation method. All the recovered products were identified using XRD, EDX as well as FE-SEM techniques.
The study of the recovery process of lead from aqueous nitrate medium using emulsion liquid membrane technique was achieved by the optimization of the extraction and pre-concentration of Pb(II) ions. This has been conducted by the method of optimizing one experimental parameter at a time. The chemical process of recovery consists of a quaternary amine salt (Aliquat 336) as ionic liquid extractant and a non-ionic surfactant (Tween20) as reagent for dispersion and emulsion formation. Thus, several experimental parameters such as carrier concentration, surfactant concentration, time and stirring speed of feed phase, initial concentration and pH of feed concentration phase were studied. Pb(II) ions extraction was optimized using tri-n-octylphosphine oxide (TOPO) as the solvating organophosphorus compound in the emulsion phase. From the results, the lead ions were extracted at 92 ± 0.04% by Aliquat 336 in the presence of TOPO. For the stage of Pb(II) pre-concentration, the nature and concentration effects of the stripping solution were studied. So, the loss of the Pb(II) ions in the membrane phase was minimal when using the nitric acid solution as a stripping solution. It was preconcentrated at 83.55%. The separation experiments of Pb(II) from Cu(II) were given on the basis of the optimal conditions of lead(II) recovery. Thus, the separation factor of lead over copper was equal to 1.47.
Separation of cobalt and nickel from sulfate media was investigated, using a extraction system of 30% 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507)+15% trioctyl/decylamine (N235)+55% sulfonated kerosene. About 41wt.% Co²⁺ was extracted with 1.6wt.% co-extraction of Ni²⁺ at O/A ratio of 2:1. Scrubbing of Ni²⁺ and stripping of Co²⁺ could be achieved from the loaded organic phase, using water and 0.05mol/L H2SO4, respectively. Cobalt extraction percentage decreased with increasing Mg²⁺ concentration, but this influence was negligible as [Mg²⁺]<0.1g/L. The favorable equilibrium pH was 4-4.8. A different E-pH curve was observed in the P507-N235 system compared to the saponified P507 system.
We studied the separation and recovery of copper(II), nickel(II), cobalt(II), zinc(II), and cadmium(II) from magnesium and calcium, using synergistic solvent extraction (SSX) in a typical hydrometallurgical waste solution. A mixture of Versatic 10 acid and Mextral 984H, diluted with Mextral DT100, was used to obtain fundamental data on pH and distribution isotherms, as well as the kinetics of extraction and stripping. We also investigated the main effects and interactions of common solvent extraction factors: the extraction pH at equilibrium, the temperature, and the extractant concentration. The synergistic effect for extracting metals was confirmed. The results showed that the addition of Mextral 984H enhanced the separation factors of copper, nickel, cobalt, zinc, and cadmium over magnesium and calcium. Compared with Versatic 10 acid alone, for a mixture of 0.5 mol·L−1 Versatic 10 acid /0.5 mol·L−1 Mextral 984H, ΔpH50 values of copper, nickel, cobalt, zinc, and cadmium were found to be > 2.0, 3.30, 2.85, 0.95, and 1.32 pH units, respectively. The ΔpH50(Zn-Mg) and ΔpH50(Zn-Ca) values were 3.27 and 2.25, respectively, indicating easy separation and recovery of copper, nickel, zinc, cobalt, and cadmium. The extraction and stripping of copper, cobalt, zinc, and cadmium were fast, with 90% of the metal transferred in 2 min. We next studied whether the metals could be stripped from the extracted liquid selectively in sequence, by using sulfuric acid at different concentrations. The influence of the molecular structure of the oxime and carboxylic acid components upon the synergistic effects was identified by numerical analysis. Excellent separation of copper, nickel, cobalt, and zinc over magnesium and calcium was achieved with this synergistic solvent extraction system.
The separation of neodymium and praseodymium was carried out from a chloride solution containing the similar composition of NdFeB magnet leach liquor. A comparative study between extractants demonstrated that the extraction efficiency of bi-functional ionic liquids (Bif-ILs) tri octylmethylammonium bis(2,4,4-trimethylpentyl)phosphate (R4NCy) and trioctylmethylammonium di(2-ethylhexyl)phosphate (R4ND) was higher than the conventional extractants such as tri-octyl methyl ammonium chloride (Aliquat 336), bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) and di-2-ethylhexyl phosphoric acid (D2EHPA) under same experimental condition. The extraction efficiency of different extractants for Nd and Pr was in the order: R4NCy > R4ND > Cyanex 272 > D2EHPA > Aliquat-336. As the extraction of Nd and Pr was maximum with R4NCy Bif-ILs, the McCabe-Thiele diagram was constructed with R4NCy which showed 2 stages at 1:1 phase ratio. A 2-stage counter current simulation study showed 98.97% Nd and 99.02% Pr extraction. The loaded organic phase was stripped with H2SO4 acid and the stripping efficiencies for Nd and Pr were 98.11% and 98.75%, respectively. The extracted species was found to beMCl3 ⋅ 3R4NCy. The thermodynamic parameters were also determined for extraction of Nd and Pr with ionic liquid.
The separation of nickel and cobalt from impurities such as manganese, magnesium and calcium using solvent extraction with Versatic 10 was largely improved by the addition of a synergistic reagent LIX63 (an α-hydroxyoxime) or 4PC (a pyridine carboxylate ester). With the organic systems containing Versatic 10 alone, the separation factors of nickel and cobalt over manganese were 6 and 15 respectively. When 4PC was added to the system, these increased to 147 and 1870 respectively, and with LIX63, they were even higher at 534 and 7720 respectively. This indicates that the synergistic solvent extraction (SSX) system with Versatic 10 and LIX63 performed very well and better than that with Versatic 10 and 4PC.
The extraction and stripping characteristics of CYANEX 301® binary extractant systems were investigated for the recovery of cobalt and nickel from sulphate solutions. The selectivity properties of these systems against calcium, manganese and magnesium were also studied. These binary extractant systems consisted of mixtures of CYANEX 301 with basic extractants (Primene® JMT, Amberlite® LA-2, Alamine® 336 and Aliquat® 336). Based on criteria such as extraction and stripping characteristics (efficiency and rates) and selectivity against calcium, manganese and magnesium, screening experiments were performed to select the most appropriate binary extractant systems. From this screening work, the CYANEX 301/amine systems all demonstrated that cobalt and nickel could be selectively extracted from calcium, manganese and magnesium. A large synergistic effect on the stripping kinetics and efficiencies of cobalt and nickel was also observed when any amine extractant was added to CYANEX 301. Among the amine extractant systems, CYANEX 301/Aliquat 336 was shown to be the most promising binary extractant system. McCabe–Thiele extraction and stripping isotherms with this system were then constructed to determine the number of stages required. Complete extraction of cobalt and nickel could be achieved in 2–3 stages while still maintaining a high selectivity against calcium, manganese and magnesium. Complete stripping of cobalt could also be achieved in 2–3 stages while complete nickel stripping was shown to still be difficult. The loading capacity of the binary system for cobalt and nickel was determined and found to be lower than the loading capacity of CYANEX 301.
The extraction and stripping characteristics of CYANEX 301 binary extractant systems were investigated for the recovery of cobalt and nickel from chloride solutions. The selectivity of these systems against calcium, manganese and magnesium was also studied. These binary extractant systems consisted of mixtures of CYANEX 301 with basic extractants (Primene® JMT, Amberlite® LA-2, Alamine® 336 and Aliquat® 336). Based on criteria such as extraction and stripping characteristics (efficiency and rates) and selectivity against calcium, manganese and magnesium, screening experiments were performed to select the most appropriate binary extractant systems. From this screening work, the CYANEX 301–amine systems all demonstrated that cobalt and nickel could be selectively extracted from calcium, manganese and magnesium. A large synergistic effect on the stripping kinetics and efficiencies of cobalt and nickel was also observed when either amine was added to CYANEX 301. Depending on the amine concentration, near complete stripping of cobalt could be achieved with all systems, while the stripping of nickel still remained very low with the amines Primene JMT, Amberlite LA-2 and Alamine 336. Among the amine extractant systems, CYANEX 301–Aliquat 336 was shown to be the most promising binary extractant system. McCabe–Thiele extraction and stripping isotherms with this system were then constructed to determine the number of stages required. Complete extraction of cobalt and nickel could be achieved in 2–3 stages while still maintaining a high selectivity against calcium, manganese and magnesium. A decrease in cobalt stripping was observed when the hydrochloric acid concentration was increased from 2 to 4 M. The hydrochloric acid concentration had a reverse effect on nickel where nickel stripping was shown to increase with increase in acid concentration from 2 to 4 M.
Solvent extraction of copper(II) and nickel(II) from aqueous acetate solutions with di(2‐ethylhexyl)phosphoric acid (D2EHPA), dissolved in n‐heptan has been investigated. The extraction of Cu(II) was found to be quantitative in neutral, acetic acid, and acetate buffer media 96%, 95%, and 85% respectively. On the other hand, the extraction efficiency of Cu(II) decreases with the increase of the salt concentration in the aqueous solution. The extraction of Ni(II) in acetate buffer media is better than in neutral, 94% and 83% respectively. In addition, mechanisms of copper(II) and nickel(II) extraction have been established in neutral, acid, salt, and acetate buffer media. The results obtained are in good agreement with the speciation calculations given by the Cheaqs v. L20.1 (A Program for Calculating Chemical Equilibria in Aquatic Systems, RIVM, Bilthoven, The Netherlands).A study of the extraction kinetics of the copper‐D2EHPA system was carried out. The mass transfer resistance was found to have a significant influence on the overall rate of the extraction of copper.At first, the extraction of an equimolar mixture of these two metals (Cu, Ni) was carried out in order to determine the optimum conditions for their separation from each other by the D2EHPA. The results showed that the selective extraction of copper(II) over nickel(II) 93% and 83%, respectively takes place at pHs=5.71 using 4.8 mmol dm D2EHPA in n‐heptan. Then, the same study was performed with tri‐butyl phosphate (TBP) organophosphorus co‐extractants. Synergistic effect has been observed on the yield of extraction of copper over nickel at 0.76 of TBP onto D2EHPA ratio in extractants mixture.
Development of a flow sheet for the solvent extraction, separation and recovery of cadmium(II), cobalt(II) and nickel(II) from chloride leach liquors of spent Ni–Cd batteries by hydrometallurgical route was investigated. Cyanex 923 showed selective separation of cadmium(II) from nickel(II) and cobalt(II). Two-stage counter-current extraction at 1:1 phase ratio and three stages of stripping with distilled water at an aqueous to organic (A:O) phase ratio of 1.75:1 gave > 99.9% Cd extraction and stripping efficiency. Studies on the separation of cobalt from nickel from the cadmium raffinate indicated Cyanex 272 as the best extractant with a separation factor > 4700. Cobalt(II) extraction efficiency of ∼ 99.9% was achieved with 0.03 M Cyanex 272 in three counter-current stages at an A:O ratio of 1.5:1. Complete stripping of metal from the loaded organic containing 0.33 g/L Co was carried out at pH 1.5 in 2 stages at an O:A ratio of 2:1. The enrichment of cobalt was about 4.7 times. More than 99% Ni recovery was achieved with 1 M TOPS 99 as the extractant from the cobalt raffinate. A complete flow sheet of the process for the separation and recovery of Cd(II), Co(II) and Ni(II) as chlorides was demonstrated.
The past decade has witnessed unprecedented growth in the development and implementation of solvent extraction technology in the extractive metallurgy of nickel and cobalt. Solvent extraction is proving to be a powerful tool. opening new opportunities for simpler, more cost efficient and environmentally sound metal refining processes. These advances, however, could not have been possible without the cooperative efforts between the nickel industry and the people and organizations involved with reagents. materials and equipment development and supply as well as solvent extraction research, aided by the accumulated knowledge and practical experience from the copper and uranium solvent extraction operations. This paper provides an overview of these developments and some of the challenges ahead.
The transport of Au(CN)2− between aqueous solutions and organic phases of the mixture of the amine Primene JMT and the phosphine oxide Cyanex 923 in xylene was studied under various experimental conditions, i.e., extractant mixtures and gold concentrations. The behaviour of the system with different organic diluents, aqueous ionic strength and the selectivity of the system with respect to the transport of different metal–cyano complexes were also investigated. The transport of gold(I) can be ascribed to a mechanism which consists of (i) a diffusion process through the feed aqueous diffusion layer, (ii) a fast interfacial chemical reaction and (iii) a diffusion of HAu(CN)2RL and HAu(CN)2RL2 (R=the amine, L=the phosphine oxide) through the membrane.
It has long been known that the stripping of Fe(III) extracted with D2EHPA is difficult since a high concentration of HCl is required. To overcome this difficulty, the usage of a mixture of D2EHPA-TBP-kerosene in the stripping of Fe(III) was investigated. It was found that this mixture is effective in the stripping of Fe(III), and that less concentrated acid solution is required as a stripping agent. Batch-type extraction or stripping experiments were conducted to simulate multi-stage counter-current extraction or stripping. It was found that use of the mixture in a three-stage operation can easily yield above 98% extraction or stripping. To examine the role of TBP in the improvement of Fe(III) stripping from the mixed solvent, the extraction of HCl with TBP and the spectrum of Fe(III) loaded organic phases were investigated. The experimental results indicated that Fe(III) exchange reaction between Fe(III)-loaded D2EHPA and HCl-loaded TBP proceeds in the mixed solvent. A possible mechanism for Fe(III) stripping from the mixed solvent, involving the reaction between the Fe(III)-D2EHPA complex and TBP in the organic phase, has been proposed.
Studies on the separation of nickel from concentrated solutions containing sodium sulphate were carried out with di(2-ethylhexyl) phosphoric acid diluted with kerosene (mostly aliphatic). Increase in extractant concentration, extent of neutralisation and organic to aqueous phase ratio increase the extraction of nickel. The plot of log D vs. log [extractant] is linear with a slope of 2.3, indicating that the extracted species is probably NiA2. Employing 0.4 M D2EHPA, nickel was extracted to the extent of 99.6% in three counter-current stages at an aqueous to organic phase ratio of 1:4. Nickel was stripped using the spent electrolyte from the loaded organic phase in three counter-current stages at an aqueous to organic phase ratio of 2.2:1 to the extent of 99.8%. Temperature in the range of 30–60°C has marginal effect on the extent of nickel stripping. The pregnant electrolyte with a pH of 4.2 and enriched by about 3.9 kg/m3 of nickel is suitable for electrowinning to produce nickel cathode.
The extraction of Fe (III) in sulfate solution by a mixture of tertiary amine and alkylphosphonic acid monoalkyl ester or dialkylphosphinic acid as solvent was studied. The stripping of iron extracted into the organic phase with sulfuric acid was also investigated. Synergism was found to be present in the extraction of Fe (III) with these two types of solvent mixture. The extraction and stripping of iron with HEHEHP as solvent with and without the addition of tertiary amine to the organic phase were compared. It has been indicated that with the addition of tertiary amine not only are the rates of extraction and stripping increased but also the concentration of sulfuric acid required for the stripping of iron in the organic phase is reduced. Satisfactory separation was obtained with this solvent mixture for removal of Fe (III) in aluminium sulfate and zinc sulfate leaching solutions.
The extraction of sulphuric acid using binary extractants is reported. The binary extractants studied consisted of equimolar mixtures of the organophosphorus acid extractants D2EHPA, PC-88A and Cyanex 302 and the amine-type extractants Alamine 336, Aliquat 336, Adogen 283 and Primene JMT. The most efficient loading from a solution initially containing 75 g/l sulphuric was obtained at an organic to aqueous phase volume ratio of 5:1 using a 50% solution of the binary extractant in Shellsol AB. The best binary extractant in terms of extraction efficiency was Alamine 336/D2EHPA. A McCabe-Thiele construction shows that relatively few equilibrium stages are required for efficient extraction. The efficiency of stripping the loaded organic phases with water is poor and the use of a basic stripping solution to increase the stripping efficiency may be necessary.
Solvent extraction (SX) has come to be one of the most important separation processes in hydrometallurgy. Phosphorus-based extractants have proved to be of particular importance, especially for the separation of cobalt from nickel. However it was not until the dialkyl phosphinic acid reagent, CYANEX 272, and its dithio analogue CYANEX 301, became available that liquors containing very low Co:Ni ratios of at least 1:40 to even >1:100 could be treated. This has opened the way to the direct application of SX for the separation of Co from Ni in liquors derived from the leaching of nickel mattes from the smelting of nickel sulphide ores and from the pressure acid leaching of nickel laterite ores. This paper describes the development of the range of Cytec extractants and, in particular, discusses the development of their application for the separation of cobalt from nickel. Examples of actual industrial operating plants will also be given and individual flowsheets discussed.
A mixed extractant system has been developed for the separation and purification of cobalt and lithium from spent lithium-ion battery leach solutions. The addition of Acorga M5640 to the Ionquest 801 organic solution generated a significant pH isotherm shift for copper with a ΔpH50 value of 3.45. As a result, the separation of iron(III), copper and aluminium from cobalt, nickel and lithium could easily be realised with the mixed extractant system.The McCabe–Thiele diagrams at an A/O ratio of 2:1 and pH 4.0 showed that three theoretical stages are needed for the extraction of iron, copper and aluminium. The extraction kinetics of iron(III) and copper was rapid, but the extraction kinetics of aluminium was slow. With the increase of temperature from room temperature to 40°C, the aluminium extraction kinetics increased substantially. It is therefore recommended that the metal extraction should be carried out at 40°C. The stripping kinetics of aluminium and copper was rapid, but iron cannot be stripped effectively. Thus an organic bleed may be required to remove the iron with higher acid concentration in the strip solution. It is proposed that in the mixed organic system, Ionquest 801 played a role of extractant and Acorga M5640 a synergist for copper extraction.A process flowsheet is proposed for recovering cobalt and lithium from spent lithium-ion battery leach solutions using the mixed Ionquest 801 and Acorga M5640 system in the first solvent extraction circuit, and Cyanex 272 in the second solvent extraction circuit. The advantage of this process is that pure cobalt and lithium products could be obtained.
Nine alkyl- and dialkyl-substituted salicylic acids were prepared and their solvent extraction behaviour towards divalent nickel, cobalt, cadmium and zinc in nitrate media was examined, both in the absence and in the presence of some neutral N-, O- and S-donor compounds (n-octyl 3-pyridinecarboxylate and octanal oxime as N-donors, tri-n-butylphosphine oxide as O-donor, and tri-n-butylphosphine sulphide as S-donor).It was found that the pH50 values for extraction of these metals by the salicylic acids themselves can be correlated with the respective pKa and steric parameters of the extractants. Addition of the N-donor compounds caused synergistic shifts in the pH50 values for all four metals, these being especially marked for nickel (up to almost 3 pH units). Addition of the S-donor compound caused substantial shifts only for cadmium (up to 2.5 pH units), and the O-donor only for zinc and cadmium (up to 1.5 pH units). The size of the synergistic shift depends on the identity of the alkylsalicylic acid, and can be correlated with variations in steric and electronic factors through the series of compounds studied. Most significantly, the shifts increase with increasing steric bulk of the alkylsalicylic acid used.Continuous variation and saturation loading methods were used to show that the complexes extracted by mixtures of 3,5-diisopropylsaIicylic acid (HA) and the neutral ligands (L) have the probable stoichiometrics MA2L4 (M = Ni, Co, Cd) and ZnA2L2 when L = octanal oxime; MA2L2 and MA2(HA)2L2 (M = Cd, Zn) when L = n-octyl 3-pyridinecarboxylate; CdA2(HA)L3 and CdA2(HA)2L2 when L = tri-n-butylphosphine sulphide; and ZnA2L when L = tri-n-butylphosphine oxide.
Metal extraction pH isotherms and extraction and stripping kinetics have been determined with Versatic 10 acid and LIX® 63 and modifier TBP in an attempt to develop synergistic SX systems for the separation, purification and recovery of nickel and cobalt from leach solutions.The combination of LIX® 63 with Versatic 10 acid resulted in significant synergistic shifts for nickel, cobalt, copper, zinc, and manganese and antagonistic shifts for calcium and magnesium. With the 0.5 M Versatic 10 acid/0.35 M LIX® 63 system, the ΔpH50 values of nickel, cobalt, copper, zinc and manganese compared to Versatic 10 acid alone were found to be 2.79, 3.50, > 2.0, 1.99 and 1.17 pH units, respectively. The ΔpH50(Mn–Ni) and ΔpH50(Mn–Co) values were found to be 1.96 pH and 2.53 pH units, respectively, indicating easy separation of nickel and cobalt from manganese, calcium and magnesium. The extraction and stripping kinetics of cobalt, copper, zinc, and manganese were fast and the extraction and stripping kinetics of nickel were slow with the Versatic 10 acid/LIX® 63 synergistic system. The nickel stripping kinetics increased with the addition of TBP. Within 2 min, the stripping efficiency of nickel increased from 18% with no TBP to 91% with 0.5 M TBP addition. The addition of TBP to the Versatic 10 acid/LIX® 63 system also improved the nickel extraction kinetics.It is proposed that in the Versatic 10 acid/LIX® 63 synergistic system, LIX® 63 plays the role of an extractant and Versatic 10 acid a synergist for nickel while LIX® 63 plays the role of a synergist and Versatic 10 acid an extractant for cobalt.
Extraction of dilute metal ions from water was performed near room temperature with a variety of ionic liquids. Distribution coefficients are reported for fourteen metal ions extracted with ionic liquids containing cations 1-octyl-4-methylpyridinium[4MOPYR]+, 1-methyl-1-octylpyrrolidinium[MOPYRRO]+, or 1-methyl-1-octylpiperidinium[MOPIP]+ and anions tetrafluoroborate[BF4]+, trifluoromethyl sulfonate[TfO]+, or nonafluorobutyl sulfonate[NfO]+. Ionic liquids containing octylpyridinium cations are good for extracting mercury ions. However, other metal ions were not significantly extracted by any of these ionic liquids. Extractions were also performed with four new task-specific ionic liquids. When these liquids contain a disulfide functional group, they are efficient and selective for mercury and copper, whereas those containing a nitrile functional group are efficient and selective for silver and palladium.
Extraction of inorganic salts from aqueous solution by organic salts dissolved in toluene has been studied; because equilibrium is readily reversible, extracted species are stripped from organic phase simply by contact with water; since no chemical energy is used, system functions generally as separation, rather than concentration system; applications include separation of divalent cations from monovalent cations.
LIX 34 liquid ion-exchange reagent was introduced commercially by General Mills in 1976. This paper studied the fundamental aspects on zinc extraction and stripping from its nitrate solution by using LIX 34 diluted with Kermac 470B as the organic extractant. pH dependency, equilibrium isotherm on extraction and stripping, temperature effect, loading capacity, sulfuric acid concentration, and rate of extraction and stripping on the system Zn2+-LIX 34-Kermac 470B were studied. The synergistic extraction of zinc by using LIX 34 mixed with D2EHPA, TBP, and MIBK as the organic extractants were also studied.
A chemically based thermodynamic model to predict the distribution coefficient has been developed for the Au(CN)-Primene JMT-Cyanex 925 system. The predictive model makes use of the extraction mechanism, speciation in the organic phase, and the equilibrium constant for the extraction reaction. The distribution coefficient of gold can be predicted by the equation DAu = K′[H+], where K′ is an effective extraction constant and [H+] is the proton concentration of the aqueous phase at equilibrium. Excellent agreement between the experimental data and the predicted value was obtained. Furthermore, for the present extraction system, the equilibrium isotherm was determined at 20°C.
DP-8R and ACORGA M5640 extractants diluted in Exxsol D100 were used to co-extract cobalt and nickel from aqueous acidic sulfate media. The influences of equilibration time, temperature, equilibrium pH and reagent concentrations on the extraction of both metals have been studied. It was observed that both cobalt and nickel extraction are slightly sensitive to temperature but are pH dependent. Metal extraction equilibria are reached within about 5 min contact time. In addition, cobalt extraction depends on the extractant concentration in the organic phase. For a solution containing 0.5 g dm−3 each of cobalt and nickel and an initial pH of 4.1, conditions were established for the co-extraction of both metals and selective stripping (with H2SO4) of cobalt and nickel. Using the appropriate reagent concentrations the yield (extraction stage) for both metals exceeded 90%, and stripping of cobalt and nickel was almost quantitative. Copyright © 2004 Society of Chemical Industry
New hydrophobic ionic liquids were synthesized from tricaprylmethylammonium chloride (Aliquat 336©) and selected Bronsted acids by a sustainable, simple and cost-saving deprotonation-metathesis route. Prepared ionic liquids were evaluated as potential extracting agents for cadmium from different aqueous solutions. High efficiency and selectivity were reached for the extraction of cadmium from a natural river matrix with tricaprylmethylammonium thiosalicylate, [A336][TS], a thiol-containing task specific ionic liquid.
The last two decades have witnessed unprecedented growth in the development and implementation of solvent extraction technology
in the extractive metallurgy of nickel and cobalt. Solvent extraction is proving to be a powerful tool, opening new opportunities
for simpler, more cost-efficient and environmentally sound metal refining processes. This article provides an overview of
some of the latest developments regarding the solvent extractants.
Cyanex 301, Cyanex 302 and Cyanex 272 were used to extract cobalt(II) and nickel(II) from a sulphate medium in order to elucidate any separation properties these phosphinic acid extractants display. All the reagents extracted cobalt selectively, Cyanex 302 exhibiting better separation characteristics than Cyanex 272, which in turn showed a higher selectivity than did Cyanex 301. The separation (pH0.5Ni-pH0.5Co) found for Cyanex 302 was 2.6 pH units, compared to 1.7 pH units for Cyanex 272 and 1.1 pH units for Cyanex 301. Based on these results and the fact that Cyanex 301 would need strong acid to strip it, an experiment was conducted using Cyanex 302 and Cyanex 272 to separate cobalt(II) and nickel(II) from a solution containing 100 g/l NiSO4·6H2O and 2 g/l CoSO4·7H2O with favourable results.Vapour pressure osmometry was used to determine the degree of aggregation of the extractants in toluene. Both Cyanex 272 and Cyanex 302 are dimeric and Cyanex 301 exists as a monomer. Slope analysis methods were used to determine the nature of the cobalt(II) and nickel(II) complexes extracted.
The extraction of zinc from ammoniacal/ammonium chloride solutions using a sterically hindered β-diketone, 4-ethyl-1-phenyl-1,3-octadione (XI-55, HA) as the extractant has been investigated in the presence or absence of tri-n-octylphosphine oxide (TOPO, B). The results indicate that the mixture of XI-55 and TOPO shows evident synergistic effects on zinc extraction. Zinc is extracted as ZnA2B by the mixture and the stability constant of ZnA2B is 2.08. Thermodynamic parameters ΔH, ΔS and ΔG are determined, which shows that the extractions of zinc by both XI-55 extraction system and the XI-55–TOPO synergistic extraction system are exothermic driven. The concentration of total ammonia has great influence on the extraction constants and distribution ratio for both extraction systems. FT-IR studies on zinc loaded organic phases confirm the non-extractability of zinc ammine complexes.
Separation and recovery of divalent cobalt and nickel ions from sulphate solutions containing 0.01 M metal ions each and 0.1 M Na2SO4 have been carried out using 0.03, 0.05 and 0.06 M sodium salts of D2EHPA, PC 88A and Cyanex 272 in kerosene. The percentage extraction of metal ions increased with increasing equilibrium pH. Cobalt was preferentially extracted over nickel with the extractants; however, 0.05 M NaPC 88A and NaCyanex 272 were found to be suitable for the separation study. The highest separation factor was achieved with 0.05 M NaCyanex 272 at equilibrium pH 6.85. Recovery of cobalt from cobalt–nickel bearing solution was achieved with 0.05 M Cyanex 272 and PC 88A at equal phase ratio followed by their stripping with 0.02 M H2SO4 at O:A ratio of 2:1. Nickel was extracted from the cobalt-free raffinate in two stages at equal phase ratio with PC 88A and Cyanex 272 followed by their stripping with 0.02 M H2SO4 at O:A ratio of 4:3 and 2:1, respectively.
The transport of iron(III) from acidic media using pseudo-emulsion based hollow fiber strip dispersion (PEHFSD) technology is investigated. As a carrier, (PJMTH+)2(SO42−) ionic liquid, generated by direct reaction of the commercially available primary amine Primene JMT and sulphuric acid, is used. Several hydrodynamic conditions were investigated: concentration of iron (0.01–1 g l−1) and sulphuric acid concentration (10−3–0.5 M) in the feed phase, carrier concentration (1–30%, v/v) and sulphuric acid concentration (1–3 M) in the organic and strip solutions, of the pseudo-emulsion phase. The values encountered for the membrane and feed resistances, 112 and 1000 s/cm, showed that the contribution of the membrane resistance is negligible, whereas the feed resistance contributes around 17% to the overall resistance value (near 5800 s/cm), thus, the interfacial resistances due to the extraction and stripping reactions appeared dominant. The performance of the system is also compared against other ionic liquids generated from available amine extractants (Primene 81R, Primene TOA, Amberlite LA2 and tridodecylamine) and other hollow fiber configurations.
The solvent extraction of some base metals by mixtures containing a carboxylic acid and an alkylpyridine synergist was studied, with particular reference to the separation of nickel from calcium in sulphate media. The dependence of the synergistic shift in the pH50 value (ΔpH50) and the Ni–Ca separation (pH50Ca–pH50Ni) on the identities of the carboxylic acid, the alkylpyridine and the organic diluent was examined. The effect of extractant concentration in the organic phase and the nature of the anion present in the aqueous phase (nitrate, chloride and sulphate) was also investigated. Large synergistic shifts were found for nickel, whereas antagonistic shifts were found for calcium, resulting in marked enhancement of the Ni–Ca separation, e.g. from 1.04 pH units for Versatic 10 acid (0.50 M in an aliphatic diluent) to 3.48 pH units for its mixture with 4-(5-nonyl)pyridine (0.50 M).
The extraction equilibria of copper(II) with Cyanex 301, LIX 984N, and their mixtures have been investigated. Extraction was studied as a function of organic phase composition, sulfuric acid concentration, pH, temperature, initial copper concentration, mixing speed, and aqueous/organic volume ratio. Considerable synergistic enhancement has been observed in the extraction of Cu(2+) with mixtures of Cyanex 301 and LIX 984N. The results demonstrate that copper ion is extracted as CuRL(2)H with synergistic mixture. The thermodynamic parameter, enthalpy change (Delta H) of Cyanex 301, LIX 984N, and their mixtures have been determined and the endothermic process has been found. The synergistic enhancement factor of copper(II) with mixtures is higher at more acidic solutions, which suggests that it is a promising synergistic extraction system for the separation of copper(II) from more acidic medium. HCl was found to be more efficient for copper stripping from loaded synergistic mixtures.
Technical Data Sheet
- Dow
Dow, 2010. Technical Data Sheet. http://www.dow.com/products2010.