scholarly journals Extraction Recovery of Vanadium(V) by Amines

2020 ◽  
Author(s):  
Lyudmila D. Kurbatova ◽  
Olga V. Koryakova ◽  
Marina S. Valova

The extraction of vanadium (V) by N-(2-hydroxy-5-nonylbenzyl)-β, β- dihydroxyethylamine was studied depending on different factors, such as pH of the medium, concentration of extracting agent, temperature and solvent type. This allowed the optimal extraction conditions to be determined. It was shown that extraction of vanadium (V) takes place with high distribution coefficients, and a complex containing a decavanadate anion and four molecules of the extractant is formed in the organic phase. The extracted vanadium (V) complex with amine is stable for more than one month. Keywords: extraction, vanadium, distribution coefficient, infrared spectroscopy

1987 ◽  
Vol 40 (1) ◽  
pp. 209
Author(s):  
J Avraamides

Distribution coefficients for iodine in the propanenitrile-water solvent system were measured as a function of the nature and concentration of various added metal halides. BothNaCl and KI at concentrations between 1 and 3 M had a positive effect on the distribution coefficient. Zinc halides, particularly zinc iodide, tended to lower the distribution coefficient significantly and also raised the conductivity of the organic phase. These studies suggest that the two-phase solvent system is suitable for application in a zinc-iodine battery.


2020 ◽  
Vol 108 (11) ◽  
pp. 873-877
Author(s):  
Tetsuji Yamaguchi ◽  
Saki Ohira ◽  
Ko Hemmi ◽  
Logan Barr ◽  
Asako Shimada ◽  
...  

AbstractSorption distribution coefficient (Kd) of niobium-94 on minerals are an important parameter in safety assessment of intermediate-depth disposal of waste from core internals etc. The Kd of Nb on clay minerals in Ca(ClO4)2 solutions were, however, not successfully modeled in a previous study. The high distribution coefficients of Nb on illite in Ca(ClO4)2 solutions were successfully reproduced by taking Ca–Nb–OH surface species into account. Solubility of Nb was studied in Ca(ClO4)2 solutions and the results were reproduced by taking an aqueous Ca–Nb–OH complex species, CaNb(OH)6+, into account in addition to previously reported Nb(OH)6− and Nb(OH)72−. Based on this aqueous speciation model, the Ca–Nb–OH surface species responsible for the sorption of Nb on illite in Ca(ClO4)2 solutions was presumed to be X_OCaNb(OH)6. Although uncertainties exist in the speciation of aqueous Ca–Nb–OH species, the result of this study proposed a possible mechanism for high distribution coefficient of Nb on illite in Ca(ClO4)2 solutions. The mechanism includes Ca–Nb–OH complex formation in aqueous, solid and surface phases.


2011 ◽  
Vol 48 (No. 3) ◽  
pp. 96-100 ◽  
Author(s):  
Ľ. Lichner ◽  
A. Čipáková

In the case of cadmium transport via soil macropores, the short-term duration of an interaction between the reactive solute in aqueous phase and soil, as well as cadmium precipitation or adsorption on particles < 10–5 m should be taken into account. Two distribution coefficients are proposed for predicting the cadmium transport in a structured soil: the matrix distribution coefficient Kdm, equal to the equilibrium distribution coefficient Kdeq and estimated using the conventional batch technique, and the macropore distribution coefficient KdM, estimated using the modified batch technique. It was found that the conventional approach (using the coefficient Kdeq only) would underestimate a penetration of the part of Cd transported in the macropores about 255-times in the loamy-sand soil in Kalinkovo, 20-times in the loam soil in Macov, and 122-times in the clay soil in Jurová in comparison with the approach proposed in this study.


1970 ◽  
Vol 9 (56) ◽  
pp. 269-277 ◽  
Author(s):  
T. E. Osterkamp ◽  
A. H. Weber

The Workman-Reynolds effect was investigated during the phase change of dilute (about 2 × 10-4 N) KCl solutions into single crystals of ice. The ice crystals were oriented with the c-axes either parallel or perpendicular to the growth direction. The solute distribution in the liquid phase. near the interface (within 10 mm), was obtained with a wire-type conductivity cell. For a crystal growth rate 8.8 μm/s the freezing potentials were + 10.0 V and + 6.0 V and the specific charge séparations were 1.3 ± 0 1 × 10-6 C/g of ice and 1 4 ± 0.1 × 10-6 C/g of ice for growth parallel and perpendicular. Respectively, to the c-axes of the ice crystals . The equilibrium solute distribution coefficient was found to be 4 × 10-3 for KCl solutions for both crystal orientations. An “apparent” (because of convection in the liquid phase) distribution coefficient ranged from 0.031- 0.074. The “apparent” diffusion coefficients ranged from 1.3–4.9 × 10-3 mm2/s and varied linearly with growth rate. The ionic distribution coefficients. K+ and K-, were approximately K+ - K- = - 2 × 10-5 and K+ + K - = 8 × 10-3 for the KCl solutions.


1982 ◽  
Vol 19 (1) ◽  
pp. 92-103 ◽  
Author(s):  
W. D. Reynolds ◽  
R. W. Gillham ◽  
J. A. Cherry

The validity of using a distribution coefficient (Kd) in the mathematical prediction of strontium and cesium transport through uniform saturated sand was investigated by comparing measured breakthrough curves with curves of simulations using the advection-dispersion and the advection equations. Values for Kd were determined by batch equilibration tests and, indirectly, by fitting the mathematical model to breakthrough data from column experiments. Although the advection-dispersion equation accurately represented the breakthrough curves for two nonreactive solutes (chloride and tritium), neither it nor the advection equation provided close representations of the strontium and cesium curves. The simulated breakthrough curves for strontium and cesium were nearly symmetrical, whereas the data curves were very asymmetrical, with long tails. Column experiments with different pore-water velocities indicated that the shape of the normalized breakthrough curves was not sensitive to velocity. This suggests that the asymmetry of the measured curves was the result of nonlinear partitioning of the cations between the solid and liquid phases, rather than nonequilibrium effects. The results indicate that the distribution coefficient, when used in advection-dispersion models for prediction of the migration of strontium and cesium in field situations, can result in significant error.


1954 ◽  
Vol 7 (2) ◽  
pp. 189 ◽  
Author(s):  
W Botttomley ◽  
PI Mortimer

Data on the partition of tropane alkaloids between an aqueous buffer phase, of varied pH, and chloroform are presented in terms of the pH at which 50 per cent. extraction occurs. The true distribution coefficient of some of the alkaloids is derived from the data. The effect of varying the organic phase has been studied. From the data obtained, the operation of an analytical partition chromatography column is described.


2014 ◽  
Vol 1030-1032 ◽  
pp. 2334-2339
Author(s):  
Yan Liang Li ◽  
Zhong Zhen Liu ◽  
Yu Fen Huang ◽  
Lan Wei ◽  
Lian Xi Huang ◽  
...  

Enantioselective partitioning of racemic omeprazole enantiomers was studied using a biphasic recognition chiral extraction system. Hydrophilic hydroxypropyl-ڂ-cyclodextrin in aqueous phase and hydrophobic D-tartaric acid hexyl ester in organic phase as chiral selectors which preferentially recognize (R)-omeprazole enantiomer and (S)-omeprazole enantiomer, respectively. Different experimental variable parameters could affect the chiral extraction efficiency. The largest distribution coefficientskS,kRand separation factorځwere obtained at concentrations o f 0.1 mol/L HP-ڂ-CD and 0.2 mol/L D-tartaric acid hexyl ester, which were 47.38, 58.65 and 1.24, respectively.kRis always larger thankSwhen using different kinds of tartaric acid derivatives as chiral selectors in organic phase. The present study also reveal the mechanism of biphasic recognition chiral extraction forR,S-omeprazole enantiomers.


2019 ◽  
Vol 9 (10) ◽  
pp. 1967 ◽  
Author(s):  
Emilio Rosales ◽  
Silvia Escudero ◽  
Marta Pazos ◽  
Mª Angeles Sanromán

The search for efficient and environmentally friendly adsorbents has positioned lignocellulosic materials as attractive and low-cost alternatives instead of synthetic materials. Consequently, the present work investigates the efficacy of untreated lime peel (LM) and pineapple core (PP) as biosorbents for Cr(VI) removal. The maximum adsorption capacities (acquired at 24 h) of these sorbents were 9.20 and 4.99 mg/g, respectively. The use of these sorbents is expected to offer a rapid and efficient solution to treat effluents containing Cr(VI). Pineapple core showed the best biosorption properties and good distribution coefficients (distribution coefficient KD 8.35–99.20 mL/g) and the optimization of the adsorption was carried out by a response surface methodology using the Box–Behnken design. Thus, the effect of pH, biosorbent dosage, and temperature were assessed during the whole procedure. Three different responses were studied—Cr(VI) removal, Cr biosorption, and distribution coefficient—and the optimal conditions for maximizing the responses were identified by numerical optimization applying the desirability function. The resulting optimal conditions were: initial solution pH 2.01, biosorbent dosage 30 g/L, and temperature 30.05 °C. Finally, the process scale-up was evaluated by the simulation of the process working with a column of 100 L using the Fixed-bed Adsorption Simulation Tool (FASTv2.1). This research presents the obtained environmental benefits: i) reduction of pineapple waste, ii) Cr(VI) reduction and biosorption, iii) shortest sorption time for Cr, iv) properties that allow the biosorption process on the flow system, and v) low-cost process.


Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 367 ◽  
Author(s):  
Katri Avarmaa ◽  
Lassi Klemettinen ◽  
Hugh O’Brien ◽  
Pekka Taskinen ◽  
Ari Jokilaakso

High-tech metals, including Ga, Ge and In, are critical for the performance of electrical and electronic equipment (EEE). None of these three metals exist in mineable levels in natural minerals, and thus their availability and production are dependent on the primary and secondary base metals (including Zn, Al and Cu) production. To secure the supply of high-tech metals in the future, their behavior, including distribution coefficients (LCu/s = [wt% M]in copper/(wt% M)in slag), in primary and secondary processes need to be characterized. This study reports three series of copper-slag distribution experiments for Ga, Ge and In in simulated secondary copper smelting and refining process conditions (T = 1300 °C, pO2 = 10−9–10−5 atm) using a well-developed drop–quench technique followed by EPMA and LA-ICP-MS analyses. This study shows how an analytical technique more traditionally applied to the characterization of ores or minerals can also be applied to metallurgical process investigation. The LA-ICP-MS analysis was used for the first time for measuring the concentrations of these minor elements in metallurgical glasses, i.e., slags, and the results were compared to the geological literature. The distribution coefficient of indium increased as a function of decreasing oxygen partial pressure from 0.03 to 10, whereas the distribution coefficient of gallium was 0.1 at 10−9 atm and decreased as the pO2 increased. The concentrations of gallium in slags were between 0.4 and 0.6 wt% and germanium around 1 ppm. Germanium was vaporized almost entirely from the samples.


1972 ◽  
Vol 9 (12) ◽  
pp. 1577-1595 ◽  
Author(s):  
Denis M. Shaw

The original continental crust developed as the residue from fractional crystallization of the mantle–crust system. Using measured distribution coefficients for K, Rb, Ba, Sr, La, Ce, Eu, Yb, and Ni, several crystallization models are tested for conformity with regional geochemical estimates of continental crustal composition.In spite of the uncertainties and approximations the predicted concentrations agree reasonably well with observation, except in the case of Yb.


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