Maciej Wiśniewski

New pyridinecarboxamides for rapid extraction of palladium from acidic chloride media

Abstract The extraction of palladium(II) from hydrochloric acid solutions of various concentrations in the presence of different amounts of sodium chloride with various defined alkylpyridinecarboxamides having one or two alkyl groups in the amide substituents at positions 2, 3 or 4 was studied. The hydrophobicity of the studied reagents was characterized by various parameters, including octanol/water distribution coefficient. It was found that the extraction of palladium(II) with monoalkylpyridinecarboxamides depends upon the number, length and position of the alkylamide group. Higher extractions are observed for the derivatives with the alkylamide group at position 3. The extraction of palladium(II) from aqueous 0.1 M HCl with N -dodecylpyridine-3-carboxamide (3-C 12 ) is rapid and the equilibrium is achieved in 30–60 s. The replacement of HCl with NaCl has only a minor effect on the extraction of palladium(II). During the extraction of palladium(II) from acidic solutions, HCl is also transferred to the organic phase. High transfer of HCl is observed for N -dodecylpyridine-3-carboxamide. A spontaneous transfer of palladium(II) to the organic phase is observed. The Vosburgh and Cooper method and the Job method were used to determine the composition of the complexes formed. Complexes with the molar ratio of palladium(II) to the extractant equal to 1:2 (PdCl 2 L 2 ) and 1:1 (Pd 2 Cl 4 L 2 ) are extracted.

Extraction of Palladium(II) Ions from Chloride Solutions with Phosphonium Ionic Liquid Cyphos®IL101

Extraction of Palladium(II) Ions from Chloride Solutions with Phosphonium Ionic Liquid Cyphos®IL101 The extraction of palladium(II) from hydrochloric acid solutions of various concentrations in the presence of different amounts of sodium chloride with phosphonium ionic liquid Cyphos®IL101 in toluene was investigated. The extraction of Pd(II) is very effective. The percentage extraction of Pd(II) from 0.1 mol dm- 3 HCl solution amounts to 97% with Cyphos®IL101. Both the increase in HCl concentration and the presence of NaCl have a negative influence on the extraction. The extent of extraction from 0.1 mol dm-3 HCl solution in the presence of 0.5 mol dm-3 NaCl is about 80% and from 3 mol dm-3 HCl is lower and amounts to 56%. The extraction of Pd(II) from aqueous 0.1 mol dm-3 HCl and from 0.1 mol dm-3 HCl in the presence of 0.5 mol dm-3 NaCl with this phosphonium ionic liquid is rapid and the equilibrium is achieved after 1 - 2 minutes. The extraction of Pd(II) from aqueous 3 mol dm-3 HCl is slower and the equilibrium is achieved after 5 - 6 minutes.

Extraction of arsenic(III) and arsenic(V) with Cyanex 925, Cyanex 301 and their mixtures

Abstract Cyanex 925, Cyanex 301 and their mixtures were used for extraction of arsenic(III) and arsenic(V) from sulphuric acid solutions. It was found that the extraction efficiency depends on the extractant, the concentration of sulphuric acid and the diluent. The efficiency of extraction increases with an increase of sulphuric acid concentration in the aqueous feed. Cyanex 925 is better for extraction of arsenic(V), while Cyanex 301 and its mixture with Cyanex 925 are better for arsenic(III). Sulphuric acid is coextracted with these extractants. Arsenic(III) and arsenic(V) can be stripped with water from loaded Cyanex 925 in the multistage process. In the first stage, the stripping of sulphuric acid is preferred. The stripping of arsenic species with water from loaded Cyanex 301 and its mixture is ineffective.

Trihexyl(tetradecyl)phosphonium bromide as extractant for Rh(III), Ru(III) and Pt(IV) from chloride solutions‡

Ruthenium, rhodium and platinum are the most expensive of noble metals. As their natural sources are limited, it is important to develop an effective process for recovering Rh, Ru and Pt from waste sources. Their main suppliers are the following industries: chemical (spent catalysts), automotive, jewellery, dental and petrochemical. This paper presents studies on the extraction of Rh(III), Ru(III) and Pt(IV) from model aqueous chloride solutions using trihexyl(tetradecyl)phosphonium bromide (Cyphos IL 102). The effects of different parameters such as the influence of shaking time, HCl and NaCl concentrations in the feed solutions and also Cyphos IL 102 concentration in the organic phase, on the extraction of these metal ions were investigated. Additionally, the effect of the ageing of Rh(III) and Ru(III) chloride solutions on the extraction of these metal ions was studied.

Removal of Zn(II) from chloride acidic solutions with hydrophobic quaternary salts

Removal of Zn(II) from chloride acidic solutions with hydrophobic quaternary salts The equilibrium of zinc(II) extraction from hydrochloric acid solutions with phosphonium and ammonium quaternary salts and their application as carriers in polymer inclusion membranes were studied. The most efficient was the extraction of zinc with the use of chlorides and bromide of ammonium and phosphonium salt (more than 90%). Quaternary ammonium and phosphonium chlorides and bromide are efficient extractants of zinc(II) from hydrochloric acid solutions. Two-fold molar excess of extractant over Zn(II) is necessary for efficient extraction (100%). Solvent extraction power of the extractants studied decreases with increasing hydrophobicity of the anion in the following sequence: QPCl > QPBr > QPBis > QACl > QABF4 > QPBF4 > QPPF6 > QPNtf2. A solution of 1 M H2 SO4 is chosen as the best stripping phase from the technological and economical point of view. Transport across polymeric inclusion membrane enables concentration of the stripping solution; however it takes a very long time.

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions Extraction of zinc(II) and iron(III) from hydrochloric acid solutions using quaternary phosphonium salts, Cyphos® IL 101, Cyphos® IL 104, Cyphos® IL109 and Cyphos® IL 111 in mixtures with toluene, was studied. Trihexyl(tetradecyl)phosphonium chloride (Cyphos® IL 101) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos® IL 104) showed the best zinc(II) and iron(III) extraction abilities. After three stages of zinc(II) extraction with Cyphos® IL 101 and Cyphos® IL 104 the efficiencies were 100 and 93.6%, respectively. Total iron(III) transport to the organic phase was achieved after two separation stages and amounted to 82.1 and 100% for Cyphos® IL 101 and Cyphos® IL 104, respectively. Zinc(II) and iron(III) could be effectively stripped from the loaded organic phases with 0.5 mol dm-3 sulfuric acid. The more hydrophobic the character of the anion type of phosphonium salts, the lower the efficiency of extraction.

Nanofiltration, bipolar electrodialysis and reactive extraction hybrid system for separation of fumaric acid from fermentation broth.

A novel approach based on a hybrid system allowing nanofiltration, bipolar electrodialysis and reactive extraction, was proposed to remove fumaric acid from fermentation broth left after bioconversion of glycerol. The fumaric salts can be concentrated in the nanofiltration process to a high yield (80-95% depending on pressure), fumaric acid can be selectively separated from other fermentation components, as well as sodium fumarate can be conversed into the acid form in bipolar electrodialysis process (stack consists of bipolar and anion-exchange membranes). Reactive extraction with quaternary ammonium chloride (Aliquat 336) or alkylphosphine oxides (Cyanex 923) solutions (yield between 60% and 98%) was applied as the final step for fumaric acid recovery from aqueous streams after the membrane techniques. The hybrid system permitting nanofiltration, bipolar electrodialysis and reactive extraction was found effective for recovery of fumaric acid from the fermentation broth.

Transport of Zn(II), Fe(II), Fe(III) across polymer inclusion membranes (PIM) and flat sheet supported liquid membranes (SLM) containing phosphonium ionic liquids as metal ion carriers

ABSTRACT In this work transport of Zn(II), Fe(II) and Fe(III) ions from chloride aqueous solutions across polymer inclusion membranes (PIMs) and supported liquid membranes (SLMs) containing one of three phosphonium ionic liquids: trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) and tributyl(tetradecyl)phosphonium chloride (Cyphos IL 167) as an ion carrier was reported. The results show that Zn(II) and Fe(III) are effectively transported through PIMs and SLMs, while Fe(II) transport is not effective. The highest values of initial flux and permeability coefficient of Zn(II) were noticed for SLM containing Cyphos IL 167. Cyphos IL 101-containing SLM is more stable than PIM.

Interfacial phenomena in solvent extraction of metals: Extraction of palladium(II)

Abstract4-Octylphenylamine, decyl isonicotiniate, decyl nicotiniate, decyl 2-hydroxyethyl sulphide and its analg with partly fluorinated alkyl group were used for palladium(II) extraction from 3M HCl. The adsorption of these compounds at toluene/HCl solution was also studied and interpreted. 4-Octylphen adsorbs at the hydrocarbon/HCl solution at much lower concentration range than other extractants and can be used as a phase transfer catalyst. The addition of 4-octylphenylamine increases the extraction rate with esters of pyridine carboxylic acids and decreases the time needed to obtain the equilibrium of extraction.

Effect of composition and ageing of chloride solutions on extraction of Rh(III) and Ru(III) with phosphonium ionic liquids Cyphos IL 101 and IL 104

ABSTRACT Rhodium(III) and ruthenium(III) were extracted from chloride solutions with phosphonium ionic liquids trihexyl(tetradecyl)phosphonium chloride or trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate in toluene. Influence of HCl and NaCl presence in the feed and IL concentration in the organic phase were determined. Rh(III) transport appeared to be inefficient, while over 70% of Ru(III) was extracted from 3 M HCl. Ru(III) extraction was affected by the feed acidity and the type of extractant used. The spectra of the extracts indicated some changes in the structure of Rh(III) and Ru(III) complexes in the organic phase. Also, ageing of feed solutions on the extraction of Ru(III) and Rh(III) was studied.