Utilizing Recyclable Task-Specific Ionic Liquid for Selective Leaching and Refining of Scandium from Bauxite Residue

Ionic liquids (ILs) have attracted great interest in the field of extractive metallurgy mainly because they can be utilized in low temperature leaching processes where they exhibit selectivity and recyclability. A major drawback in mixed aqueous-IL systems, is IL dissolution in the aqueous phase, which leads to IL losses, increasing the overall processing cost. This study advances the method for recovering scandium (Sc) from bauxite residue (BR) using as leaching agent the IL betainium bistriflimide, [Hbet][Tf2N] mixed with water, which has been reported in previous publications. Ionic liquid leachate (IL-PLS) was prepared by leaching BR with a mixture of [Hbet][Tf2N]-H2O and subjected to different stripping experiments using hydrochloric acid. The advancement, presented in this work, is related with the optimization of the metal extraction (stripping) from the IL-PLS, where an aqueous solution with high Sc concentration and minimum metal impurities and minimum IL co-extraction is produced. It is further proven that the metal cation extraction is defined by the stoichiometry of the acidic solution and the dissolution (losses) of the IL in the aqueous phase can be minimized by adjusting the volume ratio and the acid concentration. A two-step stripping process described, achieves the selective increase of Sc concentration by 8 times in the aqueous solution, while maintaining cumulative IL losses to similar levels as the optimum 1 step non-Sc selective stripping process.

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The role of association of ions in ionic liquid/molecular solvent mixtures on metal extraction

Physical Chemistry Chemical Physics ◽

10.1039/c7cp05886a ◽

2017 ◽

Vol 19 (42) ◽

pp. 28834-28840 ◽

Cited By ~ 7

Author(s):

J.-M. Andanson ◽

N. Papaiconomou ◽

P.-A. Cable ◽

M. Traïkia ◽

I. Billard ◽

...

Keyword(s):

Ionic Liquid ◽

Aqueous Phase ◽

Ionic Association ◽

Metal Extraction ◽

Solvent Mixtures ◽

Association Of Ions

Platinum extraction from aqueous phase into ionic liquid can be correlated to ionic association.

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Liquid-liquid extraction of mineral acids using Tri-n-octylamine

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v54i4.44568 ◽

2019 ◽

Vol 54 (4) ◽

pp. 339-346

Author(s):

AK Karmakar ◽

RK Biswas ◽

MF Khatun

Keyword(s):

Aqueous Phase ◽

Acid Concentration ◽

Organic Phase ◽

Volume Ratio ◽

Metal Extraction ◽

Phase Volume ◽

Concentration Region ◽

Strong Base ◽

Phase Volume Ratio ◽

Mineral Acids

The present work reports the extraction behaviors of mineral acids: HClO4, HNO3, HCl and H2SO4 (commonly found in acidic bleed solutions from the hydrometallurgical route of metal extraction processes) by tri-n-octylamine (TOA) dissolved in distilled colorless kerosene. The systems have been investigated as functions of various experimental parameters, such as time, [acid], [TOA], temperature, extraction stage and the organic to aqueous phase volume ratio (O/A). Strippings was also examined. Equilibration time is less than 60 min. The acid concentration in the organic phase at equilibrium is increased with increasing initial acid concentration in the aqueous phase for all systems. However, the is after %extraction decreased with increasing initial acid concentration in the aqueous phase. The % extraction increased remarkably with increasing [TOA] for all cases. Being the ratio of the [acid] in the organic to aqueous phase at equilibrium equal to extraction ratio, D; the log D vs. log [TOA] plot is almost a curve with slope 1 at lower concentration region and with slope ~2 at higher concentration region. The extraction efficiency of TOA varies in the order: HClO4> HNO3> HCl > H2SO4. The acid-base-neutralization (extraction) reactions are exothermic with ΔH value much higher than -57 kJ/mol obtainable for of a strong acid - strong base neutralization. The loading capacity of extractant (g per 100 g TOA) for acids varied in the order: HClO4 (30.69) > HNO3 (20.49) > H2SO4 (17.87) > HCl (10.31). On using lower organic to aqueous phase volume ratio (O/A), the organic phase saturated with acid can be obtained on stage-wise extraction. The extracted organic phase, for all systems (excepting H2SO4-system) under investigation, can be stripped effectively in a single stage by 0.10 g eq/L NaOH solution to the extents of more than 96%. However, for H2SO4-system, two-stage stripping will be found effective. Bangladesh J. Sci. Ind. Res.54(4), 339-346, 2019

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Extraction of Zinc Metal ions from Aqueous Solution Using Ionic Liquids

Global NEST Journal ◽

10.30955/gnj.003434 ◽

2020 ◽

Keyword(s):

Aqueous Solution ◽

Heavy Metal ◽

Ionic Liquid ◽

Ionic Liquids ◽

Metal Ions ◽

Heavy Metal Ions ◽

Metal Extraction ◽

Extraction Behavior ◽

Liquid Liquid Extraction ◽

Hydrophobic Ionic Liquids

<p>This work analyzes the extraction behavior of transition heavy metal Zinc and other metal ions such as Copper, and Cadmium from hydrochloride aqueous solution in the absence of chelating agents by using a novel class of hydrophobic ionic liquids. Ionic liquid for this study was synthesized based on 1-(n-alkyl)-3-methylimidazolium cations and hexafluorophosphate anions followed by the metathesis route at room temperature were evaluated. The advantages of using these ionic liquids include their simple synthesis and sustainability. Which makes them “Greener and Simpler” compared to other solvents used for metal extraction. The experimental results show that ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate, [BMPSM][PF6] entirely removed of Zinc (extraction percentage 94.4%) and other Copper and Cadmium heavy metals from the aqueous solutions. Based on the results, the use of ionic liquids for selected heavy metal ions as a substitute to the traditional extraction agents in liquid/liquid extraction of heavy metal ions shows considerable potential and is quite promising and promoting for further extraction.</p>

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TEM observation of iron oxide pillars in montmorillonite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177544 ◽

1990 ◽

Vol 48 (4) ◽

pp. 882-883

Author(s):

H. Mori ◽

Y. Murata ◽

H. Yoneyama ◽

H. Fujita

Keyword(s):

Aqueous Solution ◽

Iron Oxide ◽

Fine Particles ◽

Aqueous Suspension ◽

Volume Ratio ◽

Exchange Capacity ◽

Nano Composites ◽

Pillared Montmorillonite ◽

Topographic Features ◽

Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

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