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George P Demopoulos - One of the best experts on this subject based on the ideXlab platform.
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comparative study of iron iii separation from zinc sulphate sulphuric acid solutions using organophosphorus extractants opap and d2ehpa part ii stripping
Hydrometallurgy, 2005Co-Authors: F Principe, George P DemopoulosAbstract:Abstract Iron(III) removal from strong zinc sulphate–sulphuric acid solutions is investigated by comparing the performance of octylphenyl acid phosphate (OPAP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Two extraction temperatures were tested: 20 and 50 °C. The Aqueous Feed composition utilised (i.e. 25 g/L iron(III) as Fe 2 (SO 4 ) 3 , 90 g/L zinc as ZnSO 4 , 12.5–50 g/L H 2 SO 4 ) approximates a hot-acid leach solution composition. Ambient extraction (20 °C) yielded acceptable kinetics and loading efficiency for 0.95 F OPAP, but less favourable results for 1.25 F D2EHPA. D2EHPA extraction at 50 °C avoided the slow extraction kinetics exhibited at 20 °C, reducing the required contact time from >30 to 10 min. OPAP exhibited fast extraction kinetics (10 min contact time) at either temperature. At 50 °C, 1.25 F D2EHPA yielded a comparable iron(III) loading capacity (∼17 g/L) as that of 0.95 F OPAP at 20 °C. No Aqueous Feed neutralization was performed prior to or during extraction. A major advantage with OPAP was the low associated sulphate co-extraction. D2EHPA co-extracted approximately 20 times the sulphate amount extracted by OPAP. Fe/Zn selectivity with OPAP at 20 °C was close to that of D2EHPA obtained at 50 °C (separation factors: 3000 and 3700, respectively). However, loaded 1.25 F D2EHPA showed stability problems as it was found to precipitate over time. Preliminary scrubbing tests determined that 30 g/L (0.82 N) HCl effectively scrubs both co-extracted zinc and sulphate from either of the loaded organic phases.
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Comparative study of iron(III) separation from zinc sulphate–sulphuric acid solutions using organophosphorus extractants, OPAP and D2EHPA: Part II. Stripping
Hydrometallurgy, 2004Co-Authors: F Principe, George P DemopoulosAbstract:Abstract Iron(III) removal from strong zinc sulphate–sulphuric acid solutions is investigated by comparing the performance of octylphenyl acid phosphate (OPAP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Two extraction temperatures were tested: 20 and 50 °C. The Aqueous Feed composition utilised (i.e. 25 g/L iron(III) as Fe 2 (SO 4 ) 3 , 90 g/L zinc as ZnSO 4 , 12.5–50 g/L H 2 SO 4 ) approximates a hot-acid leach solution composition. Ambient extraction (20 °C) yielded acceptable kinetics and loading efficiency for 0.95 F OPAP, but less favourable results for 1.25 F D2EHPA. D2EHPA extraction at 50 °C avoided the slow extraction kinetics exhibited at 20 °C, reducing the required contact time from >30 to 10 min. OPAP exhibited fast extraction kinetics (10 min contact time) at either temperature. At 50 °C, 1.25 F D2EHPA yielded a comparable iron(III) loading capacity (∼17 g/L) as that of 0.95 F OPAP at 20 °C. No Aqueous Feed neutralization was performed prior to or during extraction. A major advantage with OPAP was the low associated sulphate co-extraction. D2EHPA co-extracted approximately 20 times the sulphate amount extracted by OPAP. Fe/Zn selectivity with OPAP at 20 °C was close to that of D2EHPA obtained at 50 °C (separation factors: 3000 and 3700, respectively). However, loaded 1.25 F D2EHPA showed stability problems as it was found to precipitate over time. Preliminary scrubbing tests determined that 30 g/L (0.82 N) HCl effectively scrubs both co-extracted zinc and sulphate from either of the loaded organic phases.
Koen Binnemans - One of the best experts on this subject based on the ideXlab platform.
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Selection Criteria of Diluents of Tri-N-Butyl Phosphate for Recovering neodymium(III) from Nitrate Solutions
2020Co-Authors: Mercedes Regadio, Nagaphani Kumar Batchu, Koen BinnemansAbstract:<p>Diluent plays an important role in the solvent extraction of metals. The selection of a proper diluent is important since it affects the economics of the process. The effect of different diluents (aliphatic, mixed aliphatic-aromatic and aromatic) on the solvent extraction of Nd(III) by the neutral extractant tri-<i>n</i>-butylphosphate (TBP) from nitrate Aqueous Feed solutions was studied with variation of the following process parameters: extraction kinetics, phase disengagement time, TBP concentration, nitrate concentration, loading capacity of TBP and Aqueous-to-organic phase volume ratio. The present study shows that the nature of the diluent has no effect on the extraction kinetics of Nd(III) by TBP. Phase disengagement times were relatively faster for aromatic diluents compared to aliphatic diluents. Conversely, extraction efficiencies were the highest for aliphatic diluents, slightly lower for mixed aliphatic-aromatic diluents and much lower for aromatic diluents. The poorer extraction efficiencies of aromatic diluents may be due to the lower concentration of free extractant as a result of the stronger interactions of the diluent with water and/or of the diluent with the extractant. The differences in extraction performance between aliphatic and aromatic diluents decrease with increasing nitrate concentration in the Aqueous Feed solution. Thus, the negative effect on the extraction of the aromatics in the diluent can be compensated by the positive effect of a higher concentration of salting-out nitrate ions in the Feed. The present results reveal that the selection of the diluent can be preferably based on its cost, safety and biodegradability rather than on its physico-chemical properties, since the physico-chemical properties have a limited influence on the extraction of Nd(III) by TBP at highly concentrated nitrate solutions. </p>
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Separation of samarium and europium by solvent extraction with an undiluted quaternary ammonium ionic liquid: towards high-purity medical samarium-153
RSC Advances, 2018Co-Authors: Michiel Van De Voorde, Karen Van Hecke, Koen Binnemans, Thomas CardinaelsAbstract:Long-lived europium-154 impurities are formed during the production of medical samarium-153 in a high-flux nuclear reactor. A method to separate these europium impurities from samarium was investigated using the hydrophobic quaternary ammonium ionic liquid Aliquat 336 nitrate. The separation method consists of the selective reduction of Eu3+ by zinc metal in an Aqueous Feed solution containing a high nitrate salt concentration. Subsequent extraction using undiluted Aliquat 336 nitrate leads to an efficient separation of both lanthanides in a relatively short time frame. Sm3+ was extracted to the neat ionic liquid phase much more efficiently than Eu2+. An initial approach using the addition of dicyclohexano-18-crown-6 to capture Eu2+ in the ionic liquid phase was less efficient.
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non Aqueous solvent extraction of rare earth nitrates from ethylene glycol to n dodecane by cyanex 923
Separation and Purification Technology, 2017Co-Authors: Nagaphani Kumar Batchu, Tom Vander Hoogerstraete, Dipanjan Banerjee, Koen BinnemansAbstract:Abstract A solvent extraction process comprising two immiscible organic phases has been developed for the extraction of rare earths. The more polar organic phase was ethylene glycol with dissolved rare-earth nitrate salts and lithium nitrate, while the less polar phase was a solution of the neutral extractant Cyanex® 923 dissolved in n -dodecane. The solvent extraction mechanism was determined by slope analysis and the main species in the organic phase was identified by Extended X-ray Absorption Fine Structure (EXAFS) studies. The extraction from the ethylene glycol solution was compared with extraction from an Aqueous Feed solution. When compared to Aqueous Feed solutions, the light rare-earth elements (LREEs) are less efficiently extracted and the heavy rare-earth elements (HREEs) more efficiently extracted from an ethylene glycol Feed solution, resulting into the easy separation of HREEs from LREEs. The separation factors between neighboring elements are higher for this non-Aqueous solvent extraction process than for extraction from an Aqueous Feed solution.
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Influence of the ionic liquid cation on the solvent extraction of trivalent rare-earth ions by mixtures of Cyanex 923 and ionic liquids.
Dalton transactions (Cambridge England : 2003), 2015Co-Authors: Alok Rout, Koen BinnemansAbstract:Trivalent rare-earth ions were extracted from nitric acid medium by the neutral phosphine oxide extractant Cyanex 923 into ionic liquid phases containing the bis(trifluoromethylsulfonyl)imide anion. Five different cations were considered: 1-butyl-3-methylimidazolium, 1-decyl-3-methylimidazolium, methyltributylammonium, methyltrioctylammonium and trihexyl(tetradecyl)phosphonium. The extraction behavior of neodymium(III) was investigated as a function of various parameters: pH, extractant concentration, concentration of the neodymium(III) ion in the Aqueous Feed and concentration of the salting-out agent. The loading capacity of the ionic liquid phase was studied. The extraction efficiency increased with increasing pH of the Aqueous Feed solution. The extraction occurred for all ionic liquids via an ion-exchange mechanism and the extraction efficiency could be related to the solubility of the ionic liquid cation in the Aqueous phase: high distribution ratios for hydrophilic cations and low ones for hydrophobic cations. Addition of nitrate ions to the Aqueous phase resulted in an increase in extraction efficiency for ionic liquids with hydrophobic cations due to extraction of neutral complexes. Neodymium(III) could be stripped from the ionic liquid phase by 0.5–1.0 M nitric acid solutions and the extracting phase could be reused. The extractability of other rare earths present in the mixture was compared for the five ionic liquids.
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Solvent extraction of europium(III) to a fluorine-free ionic liquid phase with a diglycolamic acid extractant
RSC Adv., 2014Co-Authors: Alok Rout, Ernesto Rezende Souza, Koen BinnemansAbstract:Europium(III) was extracted by bis(2-ethylhexyl)diglycolamic acid (DEHDGA) dissolved in the non-fluorinated ionic liquid tetraoctylammonium dodecyl sulphate, [N8888][DS]. The extraction behaviour of europium(III) was investigated as a function of various parameters: pH, extractant concentration, concentration of the europium(III) ion in the Aqueous Feed and concentration of the salting-out agent. A comparison was made with extraction of europium(III) by the acidic extractants bis(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) in tetraoctylammonium dodecyl sulphate. DEHDGA was found to be the best extractant in these experimental conditions. The ionic liquid diluent has been compared with tetraoctylammonium dodecylbenzene sulphonate and trihexyl(tetradecyl)phosphonium dodecyl sulphate. The extraction efficiency increased with increasing pH of the Aqueous Feed solution up to a maximum at pH 5, followed by a decrease in efficiency at higher pH values. Europium(III) was found to be extracted by a proton exchange mechanism. Europium(III) could be stripped from the ionic liquid phase by 1 M nitric acid.
F Principe - One of the best experts on this subject based on the ideXlab platform.
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comparative study of iron iii separation from zinc sulphate sulphuric acid solutions using organophosphorus extractants opap and d2ehpa part ii stripping
Hydrometallurgy, 2005Co-Authors: F Principe, George P DemopoulosAbstract:Abstract Iron(III) removal from strong zinc sulphate–sulphuric acid solutions is investigated by comparing the performance of octylphenyl acid phosphate (OPAP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Two extraction temperatures were tested: 20 and 50 °C. The Aqueous Feed composition utilised (i.e. 25 g/L iron(III) as Fe 2 (SO 4 ) 3 , 90 g/L zinc as ZnSO 4 , 12.5–50 g/L H 2 SO 4 ) approximates a hot-acid leach solution composition. Ambient extraction (20 °C) yielded acceptable kinetics and loading efficiency for 0.95 F OPAP, but less favourable results for 1.25 F D2EHPA. D2EHPA extraction at 50 °C avoided the slow extraction kinetics exhibited at 20 °C, reducing the required contact time from >30 to 10 min. OPAP exhibited fast extraction kinetics (10 min contact time) at either temperature. At 50 °C, 1.25 F D2EHPA yielded a comparable iron(III) loading capacity (∼17 g/L) as that of 0.95 F OPAP at 20 °C. No Aqueous Feed neutralization was performed prior to or during extraction. A major advantage with OPAP was the low associated sulphate co-extraction. D2EHPA co-extracted approximately 20 times the sulphate amount extracted by OPAP. Fe/Zn selectivity with OPAP at 20 °C was close to that of D2EHPA obtained at 50 °C (separation factors: 3000 and 3700, respectively). However, loaded 1.25 F D2EHPA showed stability problems as it was found to precipitate over time. Preliminary scrubbing tests determined that 30 g/L (0.82 N) HCl effectively scrubs both co-extracted zinc and sulphate from either of the loaded organic phases.
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Comparative study of iron(III) separation from zinc sulphate–sulphuric acid solutions using organophosphorus extractants, OPAP and D2EHPA: Part II. Stripping
Hydrometallurgy, 2004Co-Authors: F Principe, George P DemopoulosAbstract:Abstract Iron(III) removal from strong zinc sulphate–sulphuric acid solutions is investigated by comparing the performance of octylphenyl acid phosphate (OPAP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Two extraction temperatures were tested: 20 and 50 °C. The Aqueous Feed composition utilised (i.e. 25 g/L iron(III) as Fe 2 (SO 4 ) 3 , 90 g/L zinc as ZnSO 4 , 12.5–50 g/L H 2 SO 4 ) approximates a hot-acid leach solution composition. Ambient extraction (20 °C) yielded acceptable kinetics and loading efficiency for 0.95 F OPAP, but less favourable results for 1.25 F D2EHPA. D2EHPA extraction at 50 °C avoided the slow extraction kinetics exhibited at 20 °C, reducing the required contact time from >30 to 10 min. OPAP exhibited fast extraction kinetics (10 min contact time) at either temperature. At 50 °C, 1.25 F D2EHPA yielded a comparable iron(III) loading capacity (∼17 g/L) as that of 0.95 F OPAP at 20 °C. No Aqueous Feed neutralization was performed prior to or during extraction. A major advantage with OPAP was the low associated sulphate co-extraction. D2EHPA co-extracted approximately 20 times the sulphate amount extracted by OPAP. Fe/Zn selectivity with OPAP at 20 °C was close to that of D2EHPA obtained at 50 °C (separation factors: 3000 and 3700, respectively). However, loaded 1.25 F D2EHPA showed stability problems as it was found to precipitate over time. Preliminary scrubbing tests determined that 30 g/L (0.82 N) HCl effectively scrubs both co-extracted zinc and sulphate from either of the loaded organic phases.
D. Mohan - One of the best experts on this subject based on the ideXlab platform.
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Metal Ion Removal from the Aqueous Feed Using PVDF/PS Blend Ultrafiltration Membranes
Indian journal of science and technology, 2010Co-Authors: K. H. Shobana, D. MohanAbstract:Polyvinyledenefluoride-polystyrene (PVDF/PS) blend ultrafiltration membranes were prepared using phase inversion technique. Casting solutions were prepared with different compositions of poly (vinylidene fluoride) (PVDF) and polystyrene (PS) both in the presence and absence of the additive, poly (vinylpyrolidone) (PVP) using dimethylacetamide as solvent. The effects of compositions of PS and concentrations of PVP on shrinkage ratio, pure water flux and percentage of water content of the blend ultrafiltration membranes were studied. The application of the PVDF/PS blend membranes in separation of toxic heavy metal ions from Aqueous streams was also attempted and the results are discussed.
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metal ion removal from the Aqueous Feed using pvdf ps blend ultrafiltration membranes
Indian journal of science and technology, 2010Co-Authors: K. H. Shobana, D. MohanAbstract:Polyvinyledenefluoride-polystyrene (PVDF/PS) blend ultrafiltration membranes were prepared using phase inversion technique. Casting solutions were prepared with different compositions of poly (vinylidene fluoride) (PVDF) and polystyrene (PS) both in the presence and absence of the additive, poly (vinylpyrolidone) (PVP) using dimethylacetamide as solvent. The effects of compositions of PS and concentrations of PVP on shrinkage ratio, pure water flux and percentage of water content of the blend ultrafiltration membranes were studied. The application of the PVDF/PS blend membranes in separation of toxic heavy metal ions from Aqueous streams was also attempted and the results are discussed.
Michiaki Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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Separation of indium(III) and gallium(III) by a supported liquid membrane containing diisostearylphosphoric acid as a carrier
Journal of Membrane Science, 1997Co-Authors: Kazuo Kondo, Yukihiro Yamamoto, Michiaki MatsumotoAbstract:Abstract The equilibrium and kinetics of indium(III) extraction with diisostearylphosphoric acid (HR, DISPA) diluted by n-heptane were examined. The extracted species was estimated to be InR 3 . The extraction rate of indium with DISPA was measured by a shaking method in a vial tube. It was found that the extraction rate was limited by the interfacial reaction between In(OH) 2+ and the adsorbed extractant. Furthermore, the permeations of indium and gallium through a supported liquid membrane were examined. The permeation processes were limited by both the film diffusion in Aqueous Feed solution and the interfacial reaction. Indium was selectively permeated through the liquid membrane.
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Mechanisms of Samarium Extraction with Diisostearylphosphoric Acid and Its Permeation through Supported Liquid Membrane
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 1995Co-Authors: Kazuo Kondo, Tetsuya Hashimoto, Hisaharu Sumi, Michiaki MatsumotoAbstract:The extraction equilibrium of samarium (Sm) with diisostearylphosphoric acid (DISPA, HR) was measured at 303 K. The complex, SmR 3 , was formed, unlike in the case of dialkylphosphoric acids investigated previously. The extraction rate of Sm with DISPA was measured using a stirred transfer cell. The extraction rates were limited by the diffusion process. The permeation of samarium through a supported liquid membrane containing DISPA as a carrier was carried out based on the above results. Under the experimental conditions, the diffusion of samarium in the film of the Aqueous Feed or the diffusion of the complex in the membrane phase was anticipated to be the rate-determining step.