Effective Parameters Interaction Study for Cerium Extraction from Sulfuric Media Using DI-(2-ETHYLHEXYL) Phosphoric Acid (original) (raw)
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Chemical Engineering Research and Design, 2019
In the present study, the solvent extraction of cerium (IV) from sulfate medium was investigated by Cyanex 272 and 301. The main objective was to increase our understanding of the behavior of analogous extractants, but different in donor atom, which were achieved by batch and kinetics investigations. This allows better selection of extractants for similar approaches in future works. The investigation of extraction kinetics using single drop columns provides this work with a simpler approach in term of overall procedure for the separation of cerium ions from aqueous solutions, which allows finding how experimental conditions control the rate of reaction. The effects of parameters such as pH, extractant concentration, organic to aqueous volume, and temperature were studied under batch conditions. The complete extraction of 200 mg L −1 Ce (IV) at pH of 4 was obtained either by Cyanex 272 or 301 diluted in kerosene. Results shows that regarding the structural substitution of oxygen with sulfur, Cyanex 272 has a better performance in a lower concentration, while Cyanex 301 shows higher extraction percentage at lower pH. The extraction by Cyanex 272 and 301 was exothermic and endothermic, respectively. Results of reaction kinetics revealed that by considering the correction of droplets residence time, the rate of extraction either by Cyanex 272 or 301 is independent of the height of the column. Thus, the effects of extractants and cerium concentrations along with the pH of aqueous solution allowed finding the rate of extraction. The cerium mass flux increased by droplet diameter, indicating the contribution of mass diffusion in the extraction.
Solvent Extraction Method for the Separation of Cerium(III) as
Extraction experiments for Ce+3 ion from aqueous phase by new laboratory prepared Azo derivation as complexation agent 4- [N-(5-methyl isoxazol-3-yl)benezen sulfonamide azo]-1- Naphthol (AMBN) shows the optimum conditions for this extraction method was (pH= 9) (10 minutes) shaking time and 100μg (1.5x10-4M) concentration of Ce+3 ion in aqueous phase. Organic solvents effect study shows there is not any linear relation between distribution ratio (D) for extraction of Ce+3 ion and dielectric constant (ε)for organic solvents used but there is un effect for organic solvent structure on the extraction of Ce+3 ion and distribution ratio (D) values. Stoichiometric studies demonstrated the more probable structure ion pair complex extracted for Ce+3 was 1:1 .
Influence of alcohols on the extraction of cerium(IV) by Aliquat-336 in kerosene
International Journal of Mineral Processing, 2007
Tricaprylmethylammonium chloride (Aliquat-336) diluted with kerosene was used to extract cerium(IV) from nitric acid medium. Various alcohols were used as modifiers to overcome the third phase problem. The different parameters affecting the extraction process including nitric, nitrate, hydrogen ion, extractant and metal concentrations as well as the temperature were separately investigated. The effect of the investigated alcohols on the extraction process was also studied in detail at two different concentrations and correlated to their physical constants. Based on the obtained results, the extraction equilibrium was deduced and the optimum conditions for the extraction of cerium(IV) were proposed. The method was tested and applied to the separation of cerium from the hydrous oxide cake resulting from monazite sand.
Scientific Reports
Owing to the high toxicity of cerium toward living organisms, it is necessary to remove cerium from aqueous solutions. In this regard, the extraction of cerium (Ce (III)) from nitrate media by Cyanex 572 under different operating conditions was examined in this study. The effect of contact time, pH, extractant concentration, and nitrate ion concentration were investigated to characterize the extraction behavior of cerium and based on these outcomes, an extraction mechanism was suggested. The analysis of infrared spectra of Cyanex 572 before and after the extraction of cerium indicated that cerium extraction was performed via a cation-exchange mechanism. Then, the predictive models based on intelligent techniques [artificial neural network (ANN) and hybrid neural-genetic algorithm (GA-ANN)] were developed to predict the cerium extraction efficiency. The GA-ANN model provided better predictions that resulted higher R2 and lower MSE compared to ANN model for predicting the extraction e...
The extraction and separation of cerium(IV) and yttrium(III) from citric acid solution using Di-2-ethylhexyl phosphoric acid, D2EHPA, in kerosene was investigated. The effects of the different parameters on the extraction process, including the shaking time, extractant concentration, phase ratio, acid concentration as well as, temperature, were separately investigated to achieve the maximum possible separation between Ce(IV) and Y(III). The extraction constant was modeled based on the most predominant citrate cationic species at pH 4.0. The stoichiometry of the extracted species was found to be [Ce(H 2 Cit) 2 •2A(HA)] and [Y(H 2 Cit)•2A(HA)], (where HA denotes D2EHPA), based on the slope analysis method applied on the obtained results. The mean conditional extraction constants values K C.ex were found to be 4.15 × 10 2 ± 0.05 and 5.36 ± 0.28 × 10 3 for Ce(IV) and Y(III), respectively. The thermodynamic functions associated with the extraction reaction were evaluated and discussed. It was found that the extraction process is spontaneous and exothermic for both metal ions. Possible separation of Y(III) from Ce(IV) was given in terms of the separation factors at different extraction conditions.
Metallurgical Research & Technology
The solvent extraction of Cerium(III) and Lanthanum(III) from nitric acid solution using the organophosphorous extractants Di-(2-ethyl hexyl) phosphate (D2EHPA) and di-2,4,4- trimethylpentyl phosphoric acid (Cyanex272) in kerosene was investigated. In this study, the magnitude of the extraction of Ce(III) was found to be more significant with Cyanex272 than D2EHPA. D2EHPA was found to be a better extractant for La(III). Among the two extractants, Cyanex272 was used for the separation of Ce from La in three stages with an extraction efficiency of 90.2% for Ce. A 556 mg/L Ce solution was used for the scrubbing of La with an efficiency of ≈34%, which required multi stage scrubbing. The study of thermodynamic parameters such as enthalpy, entropy, and Gibbs free energy impart the exothermic and non-spontaneous process. The chemical speciation curves for lanthanum and cerium in the aqueous phase as a function of pH showed that the free La(III) and Ce(III) metal ion species were largely pr...
Emulsion Liquid Membrane Extraction of Cerium Ions from Acidic Solution Using Cyanex 301
ALGERIAN JOURNAL OF NATURAL PRODUCTS, 2015
Membrane processes for separation of chemical species from a mixture are gaining in importance and are emerging as a viable alternative to conventional separation processes. The emulsion liquid membrane (ELM) technique was regarded as an emerging separation technology and was extensively examined for potential applications in such fields as hydrometallurgy, environmental engineering, biochemical engineering, pharmaceutical engineering, and food technology. In the present work, the removal of Cerium ions from acidic solution by using an emulsion liquid membrane (ELM) technique was investigated and we obtained > 98% efficiency with the treatment. For the transport of Ce(III) ions using Cyanex 301 as extractant, the effects of extractant and surfactant concentrations, mixing speed, concentration and type of stripping solution, phase ratio, treatment ratio, and nature of diluent on the extraction rate were studies. Under the optimum conditions, solvent extraction and stripping of ...
Extraction of cerium(IV) using tributyl phosphate impregnated resin from nitric acid medium
Transactions of Nonferrous Metals Society of China, 2012
Tributyl phosphate (TBP) solvent was used for impregnation into Amberlite XAD−16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin (SIR). Undiluted TBP in a ratio to the resin support (volume to mass) of 6.0 at room temperature (RT) in 24 h was impregnated the resin with a mass ratio of 1.944, while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88. Cerium(IV) oxide concentrate, prepared from crude Egyptian monazite sand, containing 37% cerium, 1.6% thorium and about 40% the other trivalent rare earth oxides, was used to prepare cerium(IV) nitrate solution for extraction using the prepared SIR. The impregnated resin was satisfactory for Ce(IV) extraction from nitric acid medium at room temperature. Cerium loading capacity of the impregnated resin reached 95.6% of the calculated theoretical capacity (173 g/kg (Ce/SIR)) under the conditions of 51.57 g/L cerium and 2.48 g/L thorium, 5.0 mol/L free nitric acid, solution to resin ratio of 10.0 and contacting the phases for 5.0 min. The loading capacity reached 98.75% when cerium concentration was increased to 91.43 g/L under the same conditions.
A new and advantageous extraction procedure was developed for extraction of cerium (IV) from nitric acid with din -butylsulfoxide (DBSO) in perchloric acid. The extracted Ce (IV) was determined spectrophotometrically using 0.01 % solution of arsenazo-III in 3 M per-chloric acid. Various parameters such as equilibration time, metal ion concentration, effect of temperature and diverse ions on the extraction of the Ce (IV) were established. U (VI), Th (IV) and Pb (II) interfere whereas only phosphate and fluoride suppress the extraction among anions. The stoichiometric composition of the cerium complex with DBSO was determined by slope analysis and found to be 1:4. The process of extraction was found to be exothermic. Deionized water was the most appropriate solvent for back extraction of cerium. This method is easier and more sensitive than many of the reported procedures.