Separation and purification of scandium by solvent extraction and related technologies: a review

Wang, Weiwei; Cheng, Chu Yong

doi:10.1002/jctb.2655

Cited by 177 publications

(93 citation statements)

References 57 publications

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“…Previously, complete or partial recovery of Sc from bauxite residues was reported to be achieved mainly by solvent extraction, ion exchange, or the combination of these two techniques, as a result of its low concentration in the leachates [14][15][16][17][18][19][20]. Zhang et al recovered 91% of Sc from bauxite residue leachates by inorganic metal(IV)-phosphate ion exchangers, although Fe(III) was found to be an interfering ion in this process [20].…”

Section: Introductionmentioning

confidence: 99%

Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

Yagmurlu

Dittrich²,

Friedrich

2018

Metals

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This research presents a novel precipitation method for scandium (Sc) concentrate refining from bauxite residue leachates and the effect of aqueous media on this triple-stage successive precipitation process. The precipitation pattern and the precipitation behavior of the constituent elements was investigated using different precipitation agents in three major mineral acid media, namely, H 2 SO 4 , HNO 3 , and HCl in a comparative manner. Experimental investigations showed behavioral similarities between HNO 3 and HCl media, while H 2 SO 4 media was different from them because of the nature of the formed complexes. NH 4 OH was found to be the best precipitation agent in every leaching media to remove Fe(III) with low Sc co-precipitation. To limit Sc loss from the system, Fe(III) removal was divided into two steps, leading to more than 90% of Fe(III) removal at the end of the process. Phosphate concentrates were produced in the final step of the precipitation process with dibasic phosphates which have a strong affinity towards Sc. Concentrates containing more than 50% of ScPO 4 were produced in each case from the solutions after Fe(III) removal, as described. A flow diagram of the selective precipitation process is proposed for these three mineral acid media with their characteristic parameters.

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Section: Introductionmentioning

confidence: 99%

Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

Yagmurlu

Dittrich²,

Friedrich

2018

Metals

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“…Carboxylic acid extractants and ILs with a carboxyl functional group are useful for extraction and separation of metal ions. [9][10][11][48][49][50] In this study a SILP mimicking the structure of [Hbet][Tf 2 N] was synthesized (Fig. 3).…”

Section: Silps Characterizationmentioning

confidence: 99%

“…Typically, in this way many metal impurities go into the leachate as well and in concentrations much higher than that of scandium. 1,7,8 Liquid-liquid extraction is used for the recovery of Sc(III), 9 but it requires much higher initial concentrations of Sc(III) than the ones that can be found in the pregnant leach solutions.…”

Section: Introductionmentioning

confidence: 99%

Recovery of scandium(iii) from diluted aqueous solutions by a supported ionic liquid phase (SILP)

2017

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The adsorption of scandium from diluted, acidic solutions by a supported ionic liquid phase (SILP) was investigated, as part of a process for recovery of scandium from bauxite residue (red mud). Both dry impregnation and covalent linking were studied for the SILP preparation. The SILP betainium sulfonyl(trifluoromethanesulfonylimide) poly(styrene-co-divinylbenzene) [Hbet-STFSI-PS-DVB] was prepared by covalent linking of the ionic liquid to the resin and this resulted in an adsorbent suitable for scandium recovery. For a chloride feed solution, the effects of pH, contact time, adsorption capacity, desorption, reusability of adsorbent and the influence of Fe(III), Al(III) and Ca(II) on the Sc(III) adsorption were studied. The adsorption of Sc(III) from nitrate and sulfate feed solution under optimal conditions was studied as well. The adsorption kinetics followed a pseudo-second order kinetic model. Equilibrium studies at room temperature showed that the experimental data could be well fitted by the Langmuir isotherm model. The stripping of Sc(III) from the loaded SILP was achieved with 1 M sulfuric acid. The SILP was stable and could be reused for seven adsorption/desorption cycles without significant losses in its adsorption efficiency for Sc(III). IntroductionScandium belongs to the group of rare-earth elements (REEs) and nds applications in aluminum alloys, halide lamps and fuel cells.1 However, it is an expensive metal with small global production volumes. Although scandium is relatively abundant in the Earth's crust (22 ppm), there are few scandium minerals and it rarely occurs in rich ore deposits. It is mainly recovered as by-product from the production of other metals (REEs, U, Ti, W, Al, Ni, Ta and Nb).2-4 Bauxite residue (red mud), the waste industrial product of the Bayer process for alumina production from bauxite ore, can contain up to 130 ppm of scandium and it is potentially a valuable scandium resource.5,6 Scandium can partially be recovered from bauxite residue by acid leaching. Typically, in this way many metal impurities go into the leachate as well and in concentrations much higher than that of scandium. 1,7,8 Liquid-liquid extraction is used for the recovery of Sc(III), 9 but it requires much higher initial concentrations of Sc(III) than the ones that can be found in the pregnant leach solutions.1 Nevertheless, for recovery of low concentrations of Sc(III) its enrichment with a selective adsorbent in high capacity ion exchange columns could be an efficient technique. Much of the research work on Sc(III) recovery by adsorption and extraction has been performed with resins, View Article OnlineView Journal | View Issue components can contaminate the aqueous effluents. 37 In the second class of SILPs there is no discrete IL phase in the structure of the solid support. Instead, the IL can be considered as a covalently anchored ligand. Covalent linking ensures that the IL will not be leached from the support. 32,40The objective of this work is to develop a stable SILP for the adsorption of Sc(III...

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“…1 All of these applications have led to an increase in the industrial demand for scandium; unfortunately, the commercial application of scandium continues to be thwarted by its low availability; it remains difficult to obtain because it is distributed sparsely and occurs only in trace amounts in many complicated minerals. 2 As a result, scandium is usually recovered as a byproduct of uranium and tungsten production 3,4 or the processing of nickel laterite ores 5 and bauxite.…”

Section: Introductionmentioning

confidence: 99%

High‐performance polymer‐supported extractants with phosphonate ligands for scandium(III) separation

Cui

Chen

et al. 2016

AIChE Journal

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in Wiley Online Library (wileyonlinelibrary.com) As the market demand for scandium has grown, a great deal of interest has been generated in its recovery. To substantially simplify the process and provide a green alternative for scandium separation, novel polymer-supported extractants containing di(2-ethylhexyl) phosphonate and bis(2,4,4-trimethylpentyl) phosphonate, [D201][DEHP] and [D201] [C272] are proposed because they demonstrate improved adsorption capacity and selectivity toward scandium(III). Scandium(III) adsorption is significantly affected by the solution pH, with the maximum adsorption occurring at a pH of approximately 0.78. The batch adsorption data fit well with the Langmuir isotherm and pseudo-second-order kinetic models. A combination of the Fourier transform infrared and XPS spectra suggest that the complexation of oxygen atoms in phosphate groups with scandium(III) is the predominant adsorption mechanism. Additionally, the two resins were used to recover scandium from leaching liquor of nickel laterite ore. [D201][DEHP] exhibits unusual selectivity for scandium and low competitive behavior with other metals, thus increasing its market potential. V C 2016 American Institute of Chemical Engineers AIChE J, 62: 2479-2489, 2016 Keywords: polymer-supported extractants, scandium(III), adsorption mechanism, nickel laterite ore IntroductionThe recovery of scandium has received considerable academic interest, owing to its potential importance in many applications-for instance, aluminum-scandium alloys, advanced ceramics, metal halide lamps, solid oxide fuel cells, nuclear materials and lasers.1 All of these applications have led to an increase in the industrial demand for scandium; unfortunately, the commercial application of scandium continues to be thwarted by its low availability; it remains difficult to obtain because it is distributed sparsely and occurs only in trace amounts in many complicated minerals.2 As a result, scandium is usually recovered as a byproduct of uranium and tungsten production 3,4 or the processing of nickel laterite ores 5 and bauxite. 6 For example, in Australia, the nickel laterite ores contain a relatively high content of scandium and are considered to be important scandium resources. Scandium can be recovered as a byproduct during nickel and cobalt extraction operations. A typical nickel laterite ore mainly consists of Ni (1-2%), Co (0.05-0.10%), Fe (15-50%), Al (2-5%), and trace amounts of Sc (0.005-0.006%).7 Considering their increasing demand and scarcity, the recovery of valuable minor elements-particularly scandium, which is associated with nickel laterite ore-is highlighted in research.After sulfuric acid leaching under atmospheric pressure, 8 scandium is normally separated and recovered by solvent extraction and ion exchange techniques in the processing of nickel laterite ore. 9-11 However, these processes that attempt to recover scandium still face the problem that the concentration of scandium is low (below 20 ppm), but the concentrations of iron and aluminum i...

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Separation and purification of scandium by solvent extraction and related technologies: a review

Cited by 177 publications

References 57 publications

Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

Effect of Aqueous Media on the Recovery of Scandium by Selective Precipitation

Recovery of scandium(iii) from diluted aqueous solutions by a supported ionic liquid phase (SILP)

High‐performance polymer‐supported extractants with phosphonate ligands for scandium(III) separation

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