Extraction of rhodium(III) with petroleum sulfoxides from hydrochloric acid solutions

Extraction of rhodium(III) from hydrochloric acid solutions with petroleum sulfoxides was studied. The optimal conditions of its recovery were found. The composition and structure of the compound being extracted was determined by electronic absorption, ¹H NMR, and IR spectroscopies and elemental analysis.     

Extraction of chlororuthenium(III) complexes from hydrochloric acid solutions by petroleum sulfoxides

The extraction of ruthenium(II) by petroleum sulfoxides (PSOs) from hydrochloric acid solutions has been studied. The extraction of ruthenium(III) by PSOs is implemented by the coordination mechanism with the incorporation of the sulfoxide oxygen atom of the extractant into the inner coordination sphere of the ruthenium(III) ion. The composition of the extraction compound is suggested using electronic, ¹H NMR, and IR spectroscopy, the slope method, and elemental analysis.     

Extraction of rhodium(III) by a bisacylated diethylenetriamine derivative from hydrochloric acid solutions

The extraction of rhodium(III) with a bisacylated diethylenetriamine derivative from hydrochloric acid solutions was studied. Optimum conditions for rhodium(III) extraction were determined. It was found that, at a contact time to 10 min, the extraction occurred by an ion-association mechanism. At a contact time longer than 10 min, rhodium(III) was extracted by a mixed mechanism with the insertion of an extractant molecule into the inner coordination sphere of the rhodium(III) ion. The composition of the extracted compound was determined using electronic, ¹H and ¹³C NMR, and IR spectroscopy and elemental analysis, and the structure of this compound was proposed.     

Extraction of rhodium(III) by 1,3-diamyl-2-imidazolidinethione from hydrochloric acid solutions

The extraction of rhodium(III) with 1,3-diamyl-2-imidazolidinethione from hydrochloric acid solutions was studied. Optimum conditions for rhodium(III) extraction were determined. It was found that rhodium(III) was extracted from a 0.5 M solution of HCl at a phase contact time of 3 h by a coordination mechanism. The composition of the extracted compound was determined using electronic, ¹H and ¹³C NMR, and IR spectroscopy and elemental analysis. It was demonstrated that the extracting agent coordinated to the rhodium(III) ion through the sulfur atom.     

Liquid-liquid extraction of rhodium(III) from hydrochloric acid solutions with 1,2,4-triazole derivative

Liquid-liquid extraction of rhodium(III) from hydrochloric acid solutions with a 1,2,4-triazole derivative was studied. Optimal conditions for its recovery were found. Rhodium(III) was shown to be recovered in extraction system by ion-exchange reaction at the time of phase contact not longer than 5 min. When phase contact time increased, rhodium(III) is extracted by a mixed mechanism with simultaneous insertion of two extractant molecules into the inner coordination sphere of rhodium(III) ion. Composition of coordination species of recovered compounds was established by electronic, IR, ¹H and ¹³C NMR spectroscopy and functional analysis, the structure of the coordination species is proposed.     

Iridium(IV) extraction with petroleum sulfoxides from hydrochloric acid solutions

Iridium(IV) extraction with petroleum sulfoxides (PSO) from hydrochloric acid solutions is studied. Optimum conditions of extraction are chosen. It is shown that in the investigated extraction systems for a phase contact time of 30 min, iridium(IV) is extracted by the ion-associative mechanism. Electronic, ¹H NMR, and IR-spectroscopy, and elemental analysis are used to establish the structure of the extracted compound.     

Extraction of gold(III) from hydrochloric acid solutions with high-molecular aliphatic alcohols

Experiments on extraction of gold(III) from hydrochloric acid solutions with isomeric aliphatic alcohols containing 6–12 carbon atoms showed that secondary alcohols recover AuCl_4? from acid solutions with higher distribution ratios than primary alcohols do. The best alcohol that can be recommended for the extraction of gold(III) from 3–6 M HCl solutions, taking into account the solubility and extraction ability of alcohols, is 2-octanol. The possibility of efficient stripping of gold(III) from the 2-octanol phase with ammonia or thiourea solutions was demonstrated.     

Extraction of chlororuthenium(III) complexes by triazole derivatives from hydrochloric acid solutions

The extraction of ruthenium(III) by triazole derivatives from hydrochloric acid solutions has been studied. The extraction of ruthenium(III) is implemented by the ion-association mechanism. The composition of the extraction compound has been determined using electronic, ¹H NMR, ¹³C NMR, and IR spectroscopy and elemental analysis.     

Extraction of ruthenium(III) by dihexyl sulfoxide from hydrochloric solutions

The extraction of ruthenium(III) by dihexyl sulfoxide (DHSO) from hydrochloric solutions is studied. Ruthenium(III) is first extracted by a hydration/solvation mechanism followed by the incorporation of extractant molecules into the inner coordination sphere of the ruthenium(III) ion. The composition of the extracted compound is suggested proceeding from the resuls of electronic, ¹H NMR spectroscopy, IR spectroscopy, and elemental analysis.     

Extraction of palladium(II) from hydrochloric acid solutions with triacylated ethyleneamines

Extraction of palladium(II) from hydrochloric acid solutions with novel efficient extractants, triacylated ethyleneamines, was studied. The most effective extraction of palladium(II) was observed from 0.5–1 M HCl solutions. Extraction of palladium(II) from 1 M HCl solutions was found to occur through mixed (coordination and anion-exchange) mechanism. In the field of dominance of the anion-exchange mechanism of the extraction of palladium(II) with triacylated pentaethylenehexamine the concentration constant of palladium(II) extraction was calculated, and thermodynamic parameters of extraction were evaluated.     

Extraction of gold(III) by sulfur-containing calix[4,6]arenes from hydrochloric acid solutions

Thiacalixarenes 1 and 2, thiacalixarene thioether 5, and calixarene thioethers 3a–3c, 4a, and 4b are compared with respect to gold(III) extraction from hydrochloric acid solutions. The gold extractability increases in the following order: 1,2 5 3a–3c, 4a, 4b. The effect of the substituents at the sulfur atom in R₂S and in 3a–3c, 4a, and 4b is identical when cooperative effects (CE) appear for calixarene thioethers. On the basis of the extraction stoichiometry and the activities of the components of the aqueous phase, the gold distribution in the form of (AuCl₃)_nL (n = 1?4) species is quantified for c_HCl from 0.5 to 6 mol/L. A correlation is found between the gold distribution constants into various diluents and the Kamlet-Taft parameter π*.     

State of rhodium(III) in sulfuric acid solutions

The formation of rhodium(III) sulfate complexes under moderately rigorous temperature conditions was studied by ¹⁰³Rh and ¹⁷O NMR spectroscopy. The complexes [Rh₂(μ-SO₄)₂(H₂O)₈]²⁺, [Rh₂(^*μ-SO₄)(H₂O)₈]⁴⁺, and [Rh₃(μ-SO₄)₃(μ-OH)(H₂O)₁₀]²⁺ were found to be the most stable species in aged solutions.     

Extraction of iridium(IV) by dihexyl sulfoxide from hydrochloric acid solutions

The extraction of iridium(IV) by dihexyl sulfoxide from hydrochloric acid solutions was studied. Optimum conditions for the extraction of iridium(IV) were determined. It was found that an ion-association mechanism of iridium(IV) extraction took place in the test extraction systems at a phase contact time of 10 min. As the phase contact time was increased, the extraction took place by a mixed mechanism. One extractant molecule was incorporated into the inner coordination sphere of the iridium(IV) ion. This decreased the charge of the extracted complex to unity.     

Extraction of Ce(III) with naphthenic acid from nitrate solutions

Extraction of Ce(III) with naphthenic acid from nitrate solutions was studied. The composition of solvation complexes, extraction constants, and Gibbs energies of extraction were found from the dependences of the distribution coefficients on pH and compositions of the aqueous and organic phases.     

Extraction of actinium with di (2-ethylhexyl) phosphoric acid from hydrochloric and nitric acid solutions

The extraction of actinium with HDEHP from Cl^– and NO ₃ ^– systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO₃ solutions. Stability constants of the actinium complexes Ac(X^–)²⁺, X^–=Cl^– or NO ₃ ^– , were determined. Our results show that actinium formed less stable complexes with Cl^– than with NO ₃ ^– ligands.     

Sorption of gold(III) ions from hydrochloric acid solutions by aminated shungite

Sorption of gold ions by aminated shungite from chloride solutions was studied. The effects of the solution pH and process duration on the degree of recovery were considered.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11, 2004, pp. 1772–1774.Original Russian Text Copyright © 2004 by Akimbaeva, Ergozhin.     

Ion exchange equilibria in simultaneous extraction of platinum(II,IV) and rhodium(III) from hydrochloric solutions

Regularities of sorption extraction of platinum(II, IV) and rhodium(III) by anion exchangers of various physical and chemical structure in the presence of hydrochloric media were studied. It is established that AM-2B, Purolite A 500, and Purolite S 985 ionites adsorb complex anions of platinum metals employing mixed mechanism. A high affinity of the studied anionites for the studied complex anions of platinum and rhodium is established.     

Separation of rhodium from iridium with sodium borohydride and standardization of rhodium(III) solutions

Of the platinum group metal separations, that of rhodium from iridium is the most difficult. The existing gravimetric methods are too lengthy or make use of organic reagents which ultimately need to be removed before iridium can be determined. The proposed method of separation is rapid, needs no pH control, and easy to carry out. Rh(III) ions are quantitatively reduced to Rh(0) by the action of aqueous sodium borohydride. The separation is best achieved in perchlorate medium in the presence of hydroxylamine. The separation is dependent on the concentration ratio of iridium to rhodium; if this is high, some iridium is co-precipitated; if low, the rhodium obtained is free from even spectrographic traces of iridium. A new method for standardization of Rh(III) solutions with sodium borohydride is proposed.