The solvent extraction of CU (II) from chloride solutions with certain non-chelating nitrogen donor ligands

Summary in English.Bibliography: pages 96-100.The extraction of copper from chloride solutions with some aliphatic oximes as well as some pyridine carboxylates was studied and the complexes formed in the organic phase identified. The association of octanal oxime in toluene was taken into account in the extraction studies and formation constants for dimers and trimers obtained. Copper (II), Nickel (II) and Cobalt (II) are extracted by a solvating mechanism in which only the neutral MCl2 species is extractable. This reaction is largely independent of pH. Studies were also carried out on the use of the commercial reagent ACORGA CLX-20, for the selective extraction of copper from a synthetic solution simulating leach liquors obtained by ferric chloride leaching of complex sulphide ores. Results show that separation of copper from iron is dependent on the amount of acid and chloride present in the aqueous phase

Polyamine functionalised ion exchange resins: Synthesis, characterisation and uranyl uptake

A series of linear polyamine functionalised weak base anion exchange resins have been synthesised using the Merrifield resin and characterised using infra-red spectroscopy, thermogravimetry, elemental analysis and solid state 13 C nuclear magnetic resonance spectroscopy. Uptake behaviour towards uranium (as uranyl) from sulfuric acid media has been assessed as a function of pH and sulfate concentration, with comparison to a commercially available weak base anion exchange resin, Purolite S985. Synthetic polyamine resins were seen to outperform the commercial resin at industrially relevant uranyl concentrations, with a trend of increased uptake being seen with increasing polyamine chain length. Uranium loading isotherm studies have been performed and fit with the Langmuir and Dubinin-Radushkevich isotherm models, with a maximum loading capacity observed being 269.50 mg g −1 for the longest polyamine chain studied. Extended X-ray absorption fine structure experiments have been used to determine uranium coordination environment on the resin surface, showing a [UO 2 (SO 4 ) 3 ] 4− species. This coordination knowledge was employed to develop an extraction mechanism and derive an isotherm model based on the law of mass action

The effect of contaminants on the application of polyamine functionalised ion exchange resins for uranium extraction from sulfate based mining process waters

Three in-house produced polyamine functionalised ion exchange resins and Purolite S985 (a commercial ion exchange resin) have been assessed for their ability to extract UO22+ from a variety of aqueous matrices applicable to current and potential future uranium mining processes. The uptake of common contaminant species in uranium processing liquors at variable acid concentrations has been assessed, with Al3+ and MoO42− showing the most extraction, with AsO43−, Eu3+ and Fe3+ showing extractions >10% at low [H+]. Extraction of MoO42−, AsO43−, Eu3+ and Fe3+ was seen to decrease with increasing [H+]. The impact of increasing [Cl−] on UO22+ and Fe3+ extraction has been determined. Fe3+ showed low extractions by all resins, with no dependence on [Cl−]. In contrast, increasing suppression of UO22+ uptake was seen with increasing [Cl−] up to 80 g L−1, with extraction remaining constant beyond this [Cl−]. At high [Cl−] (>50 g L−1) Purolite S985 was seen to remove UO22+ from solution more effectively than all synthesised polyamine resins. The presence of Fe3+ in solution was seen to suppress UO22+ uptake by around 10% when [Fe3+]/[UO22+] increased from 0 to 2. Fe3+ extraction by all studied resins was promoted by the presence of UO22+ in solution. This was most prevalent with Purolite S985, with an extraction of 30% for [Fe3+]/[UO22+] = 2 by Purolite S985. All resins were tested using a process water from a uranium mine and have shown an ability to selectively extract UO22+ from such solutions, with the best synthetic resin recovering 15.7% more uranium than Purolite S985