Predictive capability evaluation and mechanism of Ce (III) extraction using solvent extraction with Cyanex 572

Abstract

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 efficiency of cerium by Cyanex 572. The interactive effects of each process variable on cerium extraction were also investigated systematically. pH was the most influential parameter on cerium extraction, followed by extractant concentration, nitrate ion concentration and contact time. Finally, the separation of cerium from other rare earth elements like La (III), Nd (III), Pr (III), and Y (III) was conducted and observed that the present system provides a better separation of cerium from rare heavy earth than light rare earths.

Extraction of Cerium (III) by a Solvent Extraction Technique Using Diaminododecylphosphonic Acid (DADTMTPA): Experimental, Density Functional Theory and Molecular Dynamic Studies

“…Based on these results, the addition of the nitric acid has the effect of reducing the extraction yield. It is clear from the figure that percent extraction of Ce(III) increases continuously with decreasing aqueous phase nitric acid concentrations [42,13] . This can be attributed to competitive extraction between Ce(III) and HNO 3 [12] .…”

“…It is clear from the figure that percent extraction of Ce(III) increases continuously with decreasing aqueous phase nitric acid concentrations. [42,13] This can be…”

“…The stoichiometric coefficients obtained from the plots log D versus log [DADTMTPA] and log D versus pH eq (the pH of aqueous solution in an equilibrium state)was determined by slope analysis [13,26] . The obtained results are shown in Figures 5.…”

“…Several techniques for the extraction of Cerium (III) from aqueous solutions such as membrane separation, solvent extraction, ion exchange, and adsorption. [13] Solvent extraction is the most common process used for recovery, and removal of metal ions from aqueous solutions [14] field over other adopted methods. It is one of the most significant extractions and recovery methods for precious metals such as indium, molybdenum, vanadium, rare-earth metals, and other heavy metal ions.…”

“…The unique physicochemical properties of Ce (III) show that this metal has attracted a large number of researchers to use different techniques for the cerium (III) extraction from aqueous solutions. Several techniques for the extraction of Cerium (III) from aqueous solutions such as membrane separation, solvent extraction, ion exchange, and adsorption [13] . Solvent extraction is the most common process used for recovery, and removal of metal ions from aqueous solutions [14] field over other adopted methods.…”