Recovery of Uranium (VI) from Water Solutions by Membrane Extraction

2013 ◽  
Vol 704 ◽  
pp. 66-71
Author(s):  
Grazyna Zakrzewska ◽  
Pawel Bieluszka ◽  
Ewelina Chajduk ◽  
Stanislaw Wolkowicz

The extraction of uranium from aqueous model solutions, as well as from real solutions reulting from leaching uranium ores was carried out in the system equipped with the Liqui-Cel® Extra-Flow membrane contactor with polypropylene capillary membranes. D2EHPA in toluene was used as an organic phase. Different arrangements of flow inside the membrane module were tested. The better approach appeared to be the arrangement with aqueous phase in the shell side of the contactor and organic phase inside the capillary membrane. The extraction efficiency for model solutions reached 95% and 87% for real post-leaching liquors.

Author(s):  
Moussa Toure ◽  
Guilhem Arrachart ◽  
Jean Duhamet ◽  
Stephane Pellet-Rostaing

A study has been carried out on Ta and Nb recovery by liquid-liquid extraction process using 4-methylacetophenone (4-MAcPh) as organic phase. The 4-MAcPh was compared to methylisobutylketone (MIBK) with respect to extraction efficiencies (kD values) at different concentrations of H2SO4 in the aqueous phase. The results showed a similar extraction of Nb for both solvents. However, for Ta extraction efficiency is increased by a factor of 1.3 for 4-MAcPh. In addition, the MIBK solubilized completely after 6 mol L-1 of H2SO4 against only a loss of 0.14 to 4% for 4-MAcPh between 6 and 9 mol L-1 of H2SO4. The potential of 4-MAcPh has also been studied to selectively recover Ta from a model capacitor waste solution. The results showed a selectivity for Ta in the presence of impurities such as Fe, Ni, Mn. The 4-MAcPh also presents the advantage of having physicochemical properties adapted to its use in liquid-liquid extraction technologies such as mixer-settlers.


Author(s):  
Meng Wei ◽  
Qian’ge He ◽  
Xuegang Liu ◽  
Jing Chen

Water-soluble oxa-diamide ligand, N,N,N′,N′-tetra-methyl-3-oxy-pentane-1,5-diamid (TMPDA) has been synthesized and purified. Its crystal structure, melting point, decomposition temperature, solubilities in aqueous phase and organic phase, distribution ratio between aqueous and organic phase, etc. are reported. The effect of TMPDA concentration in aqueous phase and HNO3 concentration in the equilibrium aqueous phase on the extraction efficiency of La(III), Ce(III), Pr(III), Nd(III), Zr(IV), Fe(III), Y(III), Mo(VI), Ru(III) and Pd(II) by 30% TRPO/kerosene have been studied. The results indicate that TMPDA dissolve well in aqueous phase but almost insoluble in kerosene or 30%TRPO/kerosene in the bi-phase system. It can effectively reduce the extraction of Ln(III), Y(III) and Zr(IV) into 30%TRPO/kerosene at a moderate acid system (0.24mol/L∼0.27mol/L HNO3). TMPDA is a promising stripping agent for Ln(III), Y(III) and Zr(IV) from loaded TRPO.


EKSPLORIUM ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 19 ◽  
Author(s):  
Maria Veronica Purwani ◽  
Suyanti Suyanti

ABSTRAKTelah dilakukan ekstraksi konsentrat Nd(OH)3 (neodimium hidroksida) yang mengandung Y(itrium), Sm (samarium) dan Pr (praseodimium) hasil olah pasir monasit. Tujuan penelitian ini untuk pemisahan Nd dari Y, Pr dan Sm dalam konsentrat Nd. Sebagai fasa air adalah konsentrat Nd(OH)3 dalam HNO3 dan ekstraktan atau fasa organik adalah Tri Butil Fosfat (TBP) dalam kerosen. Parameter yang diteliti adalah pH umpan, konsentrasi umpan, konsentrasi TBP dalam kerosen, waktu pengadukan dan kecepatan pengadukan. Dari hasil penelitian optimasi proses ekstraksi pemisahan neodimium dari samarium, itrium dan presedimium dalam konsentrat Nd(OH)3 hasil olah pasir monasit dengan ekstraktan TBP, diperoleh kondisi optimum  sebagai berikut: pH umpan = 0,2; konsentrasi umpan 100 gram/L, konsentrasi TBP dalam kerosen 5 %, waktu pengadukan 15 menit, kecepatan pengadukan 150 rpm. Pada kondisi ini diperoleh  FP (faktor pisah) Nd-Y, FP Nd-Pr, FP Nd-Sm masing-masing sebesar 2,242; 4,811; 4,002 dan angka banding distribusi (D) Nd = 0,236 dengan efisiensi ekstraksi Nd = 19,07%. ABSTRACTThe extraction of Nd(OH)3 (neodymium hydroxide) concentrate containing Y (yttrium), Sm (samarium) and Pr (praseodymium) as product of monazite processed has been done. The purpose of this study is to determine the separation of Nd from Y, Pr and Nd Sm in Nd concentrate. The aqueous phase was concentrated Nd (OH)3 in HNO3 and extractant while organic phase was Tri Butyl Phosphate (TBP) in kerosene. Parameters studied were pH and concentration feed, concentration of TBP in kerosene, extraction time and stirring speed. The result showed that the optimization of separation extraction neodymium from samarium, yttrium and praseodymium in Nd(OH)3 concentrated  with TBP, obtained the optimum condition of pH = 0.2, concentration of feed 100 g /L, concentration of TBP in kerosene 5%, extraction time 15 minutes and stirring speed 150 rpm. With the conditions, Separation Factor (SF) obtained for Nd-Y, Nd-Pr, Nd-Sm are 2.242, 4.811, 4.002 respectively, while D and extraction efficiency of Nd are 0.236 and 19.07%.


1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.


Author(s):  
Chi M. Phan ◽  
Son A. Hoang ◽  
Son H. Vu ◽  
Hoang M. Nguyen ◽  
Cuong V. Nguyen ◽  
...  

Abstract Background Cashew nut shell is a by-product of cashew (Anacardium occidentale) production, which is abundant in many developing countries. Cashew nut shell liquor (CNSL) contains a functional chemical, cardanol, which can be converted into a hydroxyoxime. The hydroxyoximes are expensive reagents for metal extraction. Methods CNSL-based oxime was synthesized and used to extract Ni, Co, and Mn from aqueous solutions. The extraction potential was compared against a commercial extractant (LIX 860N). Results All metals were successfully extracted with pH0.5 between 4 and 6. The loaded organic phase was subsequently stripped with an acidic solution. The extraction efficiency and pH0.5 of the CNSL-based extractant were similar to a commercial phenol-oxime extractant. The metals were stripped from the loaded organic phase with a recovery rate of 95% at a pH of 1. Conclusions Cashew-based cardanol can be used to economically produce an oxime in a simple process. The naturally-based oxime has the economic potential to sustainably recover valuable metals from spent lithium-ion batteries. Graphic abstract


2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000111-000117
Author(s):  
Houari Cobas Gomez ◽  
Jéssica Gonçalves da Silva ◽  
Jocasta Mileski Machado ◽  
Bianca Oliveira Agio ◽  
Francisco Jorge Soares de Oliveira ◽  
...  

Abstract The present work shows a ceramics microfluidic device for partial solvent extraction scheme. The technology used for device fabrication was Low Temperature Cofired Ceramics (LTCC) which allows us for complex and chemical resistant 3D microfluidic devices. The proposed system aims to partially extract the solvent present in a mixture containing aqueous and organic phases. This scheme uses a 3D flow focalization in order to improve the solvent diffusion into the external aqueous phase. The device is composed by three different parts, the input channels distribution, the main channel and the output channels distribution. The designed input channels distribution ensures a centered 3D focalized solvent stream along the main channel. The focalized solvent mixes with the surrounding water thanks to diffusion. Projected output channels take the central fluid out separately from the surrounding. Thus the device has two different outputs, one for the focalized fluid and another one for the waste fluid, which is the aqueous phase plus solvent. For a device concept proof, acetone and water were used as organic and aqueous phases, respectively. COMSOL Multiphysics was used for device microfluidics and chemical transport simulation. The extraction efficiency was the variable used as indicator for device performance validation. The flow rate ratio between phases, total flow rate, main channel length and focalized stream channel output hydraulic diameter (ODH) were used as process variables for simulation purposes. A factorial experimental planning was used in order to analyze the extraction efficiency taking into account process variables effects. From simulation results it was determined main channel length and ODH as the variables with stronger effect on extraction efficiency. Obtained simulated efficiencies were as high as 80.6%. Considering previous results observations a microfluidic device was fabricated with a main channel length of 21,4 mm and ODH of 214,63 μm. Gas chromatography was used to measured acetone concentration in outputs samples and from here the extraction efficiency. Experimental results were in agreement with simulation, returning extraction efficiencies in the order of 80.8% ± 2.2%.


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