Phosphine oxide mediate transport: modelling of mass transfer in supported liquid membrane transport of gold (III) using Cyanex 923

Alguacil, Francisco José; Coedo, Aurora Gómez; Dorado, M. T.; Padilla, Isabel

doi:10.1016/s0009-2509(01)00014-8

Cited by 27 publications

(13 citation statements)

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“…ii) particle-diffusion controlled process [21] ln(1 -F 2 ) = -kt (4) iii) moving boundary process [22] 3 -3(1 -F) 2/3 -2F = kt (5) in all the above equations, k is the corresponding rate constant. The test of the mathematical models used to explain the adsorption of gold (III) onto the resin (Table 3) shows that the metal uptake can be well explained by either film and particle-diffusion controlled processes.…”

Section: Gold Adsorptionmentioning

confidence: 99%

“…Among the various separation/concentration steps, the use of liquid-liquid extraction, membrane technologies, carbon adsorption and ion exchange has been described [1][2][3][4][5]. In many cases, the adsorption of a solute in a solid support has the advantage over liquid-liquid extraction or even membrane technologies in that no mixing and settling requirements have to be fulfilled and organic phase loss through entrainment is eliminated, also the use of an intermediate step such as filtration is avoided.…”

Section: Introductionmentioning

confidence: 99%

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Processing of residual gold (III) solutions via ion exchange

2005

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IntroductionWithin the context of gold extraction, the dissolution step of gold-bearing materials is carried out using two main aqueous media: cyanide or chloride solutions, and if the first used the leaching of gold from raw materials, the latter is useful to recover this precious metal from secondary materials and residues, i.e. anode slimes and jewelry scrap. Both dissolution media required both a complexant (cyanide or chloride) and an oxidant (air or nitric acid/chlorine) to achieve acceptable leaching rates and yields.In the particular case of chloride leaching and once gold is dissolved, the metal is presented in the solution as the gold (III)-chloro complex (AuCl4 -) with square planar structure.Very often, and prior to the ultimate gold recovery, a solution purification and/or concentration step is needed in order to produce a higher grade solution. Among the various separation/concentration steps, the use of liquid-liquid extraction, membrane technologies, carbon adsorption and ion exchange has been described [1][2][3][4][5]. In many cases, the adsorption of a solute in a solid support has the advantage over liquid-liquid extraction or even membrane technologies in that no mixing and settling requirements have to be fulfilled and organic phase loss through entrainment is eliminated, also the use of an intermediate step such as filtration is avoided.Due to the anionic nature of the gold (III)-chloro complex, the use of anionic exchangers (and also chelating resins) on the adsorption of this precious metal had been reported in the literature [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. In the present work, the adsorption and elution of gold (III) from hydrochloric acid solutions were investigated using the anionic exchange resin Lewatit MP-64. The influence of various parameters affecting the metals adsorption on the resin is studied and a kinetic study to explain the metal uptake is presented, whereas metal elution from the loaded resin is studied using acidic thiourea solutions. The final recovery from the eluates is accomplished by the use of an alkaline borohydride solution. ExperimentalThe ion exchange resin Lewatit MP-64 (Fluka) was used to adsorb gold (III) from hydrochloric acid solutions. Lewatit MP-64 is a macroporous medium-basic anion exchangecrosslinked polystyrene matrix resin containing tertiary and quaternary ammonium groups (Cl -form-free base). Prior to its use for gold adsorption, the resin was dry until constant weight. Aqueous Au(III) stock solution was prepared from solid HAuCl4 (Fluka), whereas working solutions were prepared by dilution. Other chemicals used in the present investigation were of AR grade.Batch adsorption (elution) experiments were carried out by mixing (750 min The processing of gold (III)-hydrochloric acid solutions by the anionic ion exchange Lewatit MP-64 resin has been investigated. The influence of several variables such as the temperature, the hydrochloric acid and metal concentrations in the aqueous solution and the variation of the amount of resin ...

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Section: Gold Adsorptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Processing of residual gold (III) solutions via ion exchange

2005

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“…Separation and recovery of copper [14][15][16][17][18], zinc [19][20][21], nickel [22][23][24], alkali metals [25], precious metals [26][27][28][29], rare earth metals [30][31][32][33][34], etc., from aqueous technological solutions and wastewater purification based on supported liquid membranes has intensively been studied. One of the problems is that when H + concentration difference is used as a driving factor to transfer metal ions, with time this difference decreases and the process stops.…”

Section: Mechanism and Kinetic Studies Of Slm Based Separationsmentioning

confidence: 99%

Recent advances in supported liquid membrane technology

Kocherginsky

Yang

Seelam

2007

Separation and Purification Technology

408

186

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“…In addition, an FSSLM system has been used to transport HFeCl4 species through a PVDF membrane with the carrier of Cyanex 923 from a solution containing chloride ions [26]. Alguacil, et al [27] investigated the transport of Au(III) in the form HAuCl4 through a PVDF membrane film impregnated in Cyanex 923 from an HCl solution. Results showed good transport efficiency for gold species.…”

Section: Introductionmentioning

confidence: 99%

Non-Dispersive Extraction of Ge(IV) from Aqueous Solutions by Cyanex 923: Transport and Modeling Studies

Haghighi¹,

Irannajad²,

Coll³

et al. 2019

Preprint

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A transport process was studied from an aqueous solution containing oxalic acid and 100 mg/L Ge using a flat sheet supported liquid membrane (FSSLM) system. Cyanex 923 immobilized in a polytetrafluoroethylene membrane was employed as a carrier. The solution chemistry and related diagrams were applied to study the transport of germanium. The effectual parameters such as oxalic acid, carrier concentration, and strip reagent composition were evaluated in this study. Based on the results, the oxalic acid concentration of 0.075 mol/L and the carrier concentration of 20 %v/v were the condition in which the efficient germanium transport occurred. Among strip reagents, NaOH (0.04-0.1 mol/L) had the best efficiency to transport germanium through the SLM system. Furthermore, the permeation model was obtained to calculate the mass transfer resistances of the membrane (Δm) and feed (Δf) phases. According to the results, the values of 1 and 1345 s/cm were evaluated for Δm and Δf, respectively.

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Phosphine oxide mediate transport: modelling of mass transfer in supported liquid membrane transport of gold (III) using Cyanex 923

Cited by 27 publications

References 27 publications

Processing of residual gold (III) solutions via ion exchange

Processing of residual gold (III) solutions via ion exchange

Recent advances in supported liquid membrane technology

Non-Dispersive Extraction of Ge(IV) from Aqueous Solutions by Cyanex 923: Transport and Modeling Studies

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