Orthogonal Array Design for the Optimization of Supercritical Carbon Dioxide Extraction of Different Metals from a Solid Matrix with Cyanex 301 as a Ligand

Abstract

In this study, different metal cations such as Ag+, Pd2+, Mn2+, In3+, Au3+, and Bi3+ were removed from a solid matrix using supercritical CO2 containing cyanex 301 as a ligand. When the solvating power of supercritical CO2 is combined with the metal ion complexing power of an organic ligand, a clean alternative to conventional liquid−liquid and liquid−solid extraction is obtained. An orthogonal array design (OAD), OA9 (34), was employed as a chemometric method for the optimization of the supercritical fluid extraction (SFE) of metal cations from a solid matrix. Four parameters, namely, the pressure and temperature of the supercritical fluid, the dynamic extraction time, and the volume of modifier, were studied and optimized by a three-level OAD in which the interactions between the parameters were temporarily neglected. To optimize the SFE condition for each cation, nine experiments were performed in random order. Determinations of the extracts were performed by atomic absorption spectroscopy. The effects of parameters were studied using analysis of variance (ANOVA). The results showed that Ag+, Pd2+, Mn2+, In3+, Au3+, and Bi3+ could be effectively extracted from the solid matrix by using supercritical fluid extraction and cyanex 301 as a chelating agent. Finally, the experimental conditions providing the highest extraction yield inside the experimental domain considered were proposed.

Perfluorinated oxygen- and sulfur-containing compounds as extractants for gold(III)

“…In particular, silver is quantitatively removed (within the limits of detection). Recent reports have shown that Ag + can be extracted into scCO 2 using CYANEX 301 with 92% extraction [32]. In conclusion, we have shown that highly fluorinated P=O and C=O ligands are effective extraction agents under solid-liquid extraction conditions for gold(III) and can be extended to other metals of interest in e-waste.…”

Leaching Processes

“…The choice of the complexing agent is critical for the extraction. Some characteristics are required, such as: high stability of the metal complex, fast complexation kinetics, large solubility of the complexing agent, metal complexes formed in pure or modified supercritical carbon dioxide, and specific complexing, to allow selective extraction for the metal ion or a group of metal ions [38].…”

“…The use of the chelating agent Cyanex 301 has been investigated in the extraction of metals from solid matrices using supercritical CO 2 modified with methanol because of the high solubility of Cyanex 301 in supercritical CO 2 [38,39]. Using Cyanex 301 in a synthetic mixture of solid samples of Ag, Au, Bi, In, Mn and Pd, a significant extraction of these metals could be achieved.…”

Statistical Optimization of a Novel Approach for the Reductive Debenzylation of 2,4,6,8,10,12-Hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane Using Pd@SiO2 Nano Catalyst

“…It is a powerful tool in the design of experiments because it can provide a simple, efficient, and systematic approach for optimizing the performance, quality, and cost [17][18][19][20][21][22]. It is notable that the Taguchi method can determine and separate the effects of different parameters with the aid of data obtained via performing experiments according to a proposed orthogonal array [23][24][25]. Therefore, many academic research groups have used Taguchi as a robust method for statistical optimization [26][27][28].…”