Highly Efficient Extraction of Cadmium(II) in Nitrate Medium by Quarternary Ammoniums (original) (raw)
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Hydrometallurgy, 2016
The experimental results of cadmium extraction from sulfate medium using two ionic liquids trihexyl (tetradecyl)phosphonium chloride (Cyphos IL 101) and trioctylmethylammonium chloride (Aliquat 336) diluted in kerosene were presented. The extraction of cadmium was more pronounced with Cyphos IL 101 in comparison to Aliquat 336. The percentage extraction of cadmium increased with increase in aqueous phase pH with Aliquat 336 whilst it does not vary so much with Cyphos IL 101. Fast extraction equilibrations were achieved for both Cyphos IL 101 and Aiquat 336. Quantitative extraction (99%) of cadmium ions was found using 0.04M Cyphos IL101 and 0.2 M Aliquat 336, respectively. The extraction processes were endothermic for both ionic liquids. The proposed complexes formed in the organic phases were CdSO 4 .3R 3 RPCl for Cyphos IL 101 and CdSO 4 .3R 3 RNCl for Aliquat 336. Different stripping agents were tested for complete back extraction of cadmium from the loaded organic phases and 70% of cadmium ions were stripped using 0.1M EDTA + ammonia buffer in 1:1 ratio from the loaded organic phase of Cyphos IL 101 whereas 0.1M EDTA + ammonia buffer in 4:1 ratio could strip 75% cadmium form the loaded organic phase of Aliquat 336. Separation of cadmium from nickel and zinc was possible from a ternary mixture containing 0.1 gpL of each metal ion using 0.04 M Cyphos IL 101 in kerosene. Mc-Cabe-Thiele plot showed that cadmium could be completely removed from the mixture in two stages at O:A ratio of 2:3.
Review on solvent extraction of cadmium from various solutions
Hydrometallurgy, 2000
Cadmium has wide application in the manufacturing of alloys, batteries, pigments and metal plating. The solid and liquid waste is generated during the production and at the end of service life. The recovery and recycling of cadmium from these waste materials is necessary to gain the metal values and protect the environment from hazard. In hydrometallurgical processes, solvent extraction is an important process for the recovery of non-ferrous metals from different aqueous leach liquor and waste effluent/solutions. In present paper, the solvent extraction processes for the extraction and recovery of hazardous metal cadmium from aqueous solutions associated with commonly metallic and non-metallic ions, such as sulfate, chloride, nitrate and phosphate have been reviewed. Different process parameters, viz. pH, organic- to -aqueous ratio, kinetics of extraction and stripping to establish the conditions required for the extraction of cadmium and formation of a complex in the organic phase from different solutions, have been reported. The studies show the possibility of extraction and separation of cadmium from different solutions containing other metallic ions using anionic, cationic, solvating or mixed extractants. However, further attempts are also being made to develop selective organic extractants to recover cadmium efficiently on a commercial scale. The findings of these studies are also reported.► SX is potential tool for separation/ purification of Cd from aq. solutions. ► Based on solution composition, the extractant or mixed extractants can be selected. ► Cyanex 302, Cyanex 923, PC 88A and D2EHPA are found effective. ► D2EHPA has commercial potential for extracting Cd from solution.
International Journal of Molecular Sciences, 2020
This study investigates the separation of two heavy metals, Cd(II) and Cu(II), from the mixed synthetic feed using a liquid-liquid extraction. The current study uses tri-octyl methylammonium chloride (Aliquat 336) as the extractant (with tributyl phosphate (TBP) as a phase modifier), diluted in toluene, in order to investigate the selective extraction of Cd(II) over Cu(II) ions. We investigate the use of ethylenediaminetetraacetic acid (EDTA) as a masking agent for Cu(II), when added in aqueous feed, for the selective extraction of Cd(II). Five factors that influence the selective extraction of Cd(II) over Cu(II) (the equilibrium pH (pHeq), Aliquat 336 concentration (Aliquat 336), TBP concentration (TBP), EDTA concentration (EDTA), and organic to aqueous ratio (O:A)) were analyzed. Results from a 25–1 fractional factorial design show that Aliquat 336 significantly influenced Cd(II) extraction, whereas EDTA was statistically significant for the antagonistic effect on the E% of Cu(II)...
Ethiopian Journal of Science and Technology, 2017
Solvent extraction is an energy-efficient technology which uses two immiscible phases. In this regard, solvents like hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate based ionic liquids have been used. The hydrophilicity of the metal ions is a challenge to use this method. Coordinating the metal ions by ligands, lowering the pH of the aqueous phase, modifying the ionic liquid itself in such a way that it can coordinate with the metal ions, employment of large ionic liquid to aqueous phase ratio (minimum of 1:1) were also the attempts made to improve the distribution coefficient of the ionic liquids. All these efforts are problematic in hindering the applications of ionic liquids in extraction. In this report, the extraction efficiencies of ionic liquids (C 4 mim][PF 6 ], [C 6 mim][PF 6 ] , [C 8 mim][PF 6 ] and [C 10 mim][PF 6 ]) from water samples containing Cd 2+ using very small ionic liquid to water ratio (1:6 and 1:12) from a solution of concentrations 0.005 mg/L with out using any coordinating agent as an extractant and the need of changing the pH are disclosed. While ionic liquids to aqueous phase ratio 1:12 demonstrated extraction efficiencies of 75%, 83.75%, 87.50% and 100%, respectively; the 1:6 ratio extracted 87.50%, 100%, 100% and 100%, respectively which shows suitability of the later ratio for better extraction. Moreover, the recyclabilities of [C 6 mim][PF 6 ] and [C 8 mim][PF 6 ] was investigated and the result showed that they can be used at least for five cycles. A Linear calibration curve with good coefficient of determination was obtained during the analysis for determination of the metal in the extracts.
Greener synthesis of new ammonium ionic liquids and their potential as extracting agents
Tetrahedron Letters, 2008
New hydrophobic ionic liquids were synthesized from tricaprylmethylammonium chloride (Aliquat 336 Ó ) 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.
2022
An in-situ solvent formation microextraction technique as another attractive mode of homogeneous liquid-liquid microextraction, was developed successfully for the sensitive extraction of cadmium ion. In this technique use green extracting solvent such as ionic liquids that are environment lover. So, because using ionic liquids, this technique is much safer than other extraction methods which use toxic common organic solvents. Functionalized ionic liquid of 3-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)ethyl)-1-methylimidazolium bromide was used as extractant and organic phase which has double role including complexing agent and extractant, so to extraction of cadmium ion, not need to any complexing agent. To optimization of extraction conditions, several analytical parameters affected on microextraction efficiency including sample pH, functionalized ionic liquid dosage, counter-ion amount and centrifugation conditions were studied. To show abilities of the method, the figures of merits...
The extraction behavior of (Cd (II), Cu (II), Fe (II), and Zn (II)) metal ions was studied in an aqueous biphasic system formed from poly ethylene glycol and sodium Sulphate in the presence of iodide (KI) and thiocyanate (KSCN) as extractants. The extraction percentage was determined at constant temperature of 25 o C, PH of 2.5 and mixing time of 10 min. and as a function of the following variables: • Concentration of (KI) or (KSCN) solvents between (0.1-0.7) ml of 2 g/l solution. • Volumetric phase ratio of PEG to Na 2 SO 4 in the range of (0.5-3). • Initial concentrations of the metal ions between (0.5-0.15) ml of 1 g/l metal solution added. The extraction percentage (%) of metals is mainly increased with the increasing of each concentration of the extractant, phase ratio, and the initial concentrations of the metal ions. The extraction percentage of (Cu (II), Fe (II), and Zn (II)) was higher for the system containing (SCN-) than (I-), while the extraction (%) of Cd (II) was higher in the system containing (I-) than (SCN-). The mixtures consist of (0.5) ml of initial concentration of metal ions, (0.7) ml of (KSCN), (3) of (PEG/Na 2 SO 4) volumetric phase ratio had the best results of the extraction of (Cd, Cu, Fe, and Zn) which equal to (87, 92, 92, and 80) % respectively.
The solvent extraction of cadmium (II) from sulfate medium by bis (2-ethylhexyl) phosphoric acid (D2EHPA) diluted in toluene was investigated. Optimum pH range for extraction of Cd (II) is 5 to 6, by use of 0.1 M of organic reagent in toluene. Then, Cd (II) was stripped with 4.0 M HCl from Organic phase. The effect of temperature on the extraction was carried out by temperature variation from 278 to 318 K and has led to that the temperature variation has negligible effect on extraction process. Extraction and stripping equilibrium times were studied to determine the optimum time of cadmium extraction reaction rate. The stoichiometry of the probable extracted species was determined on the basis of slope analysis by plotting log D versus log [(HR) 2 ] curve (D is the ratio of distribution of cadmium in organic/aqueous phase and (HR) 2 is dimeric form of extractant). Cadmium is extracted by a cation-exchange mechanism as CdR 2 .2HR.
Study of Cadmium Extraction with Aliquat 336 from Highly Saline Solutions
Journal of Solution Chemistry, 2018
First, I would like to thank my supervisor, Professor Jon Petter Omtvedt, for his support and guidance throughout this work. I would especially thank him for his great patience during our many discussions. I would also like to take this opportunity to thank my co-supervisors. Senior advisor, Dag Øistein Eriksen, for always helping with the initial work of the manuscripts and always suggesting new possible techniques or instruments for further investigations. Professor Eddy Walter Hansen, for his enthusiasm and help with our experimental results. Professor Grethe Wibetoe, for great discussions and an unparalleled eye for detail.