Aqueous solutions hydrometallurgy

Strzelbicki J and Charewicz W. The liquid surfactant membrane separation of copper, cobalt and nickel from multicomponent aqueous solutions. Hydrometallurgy 1980 5 243-254. 

Extraction can be used to separate and preconcentrate the analyte component(s), to recover valuable components from aqueous solutions (hydrometallurgy, biotechnology), and also to determine the stoichiometry of extracted complexes. In the latter case, the relations log D versus pH and log D versus logHL are considered, and the composition of the complex can be determined from the slopes of the linear parts of these relationships. 

Such reactions are discussed at appropriate points throughout the book as each individual compound is being considered. A particularly important set of reactions in this category is the synthesis of element hydrides by hydrolysis of certain sulfides (to give H2S), nitrides (to give NH3), phosphides (PH3), carbides (C Hm), borides (B Hm), etc. Useful reviews are available on hydrometallurgy (the recovery of metals by use of aqueous solutions at relatively low temperatures), hydrothermal syntheses and the use of supercritical water as a reaction medium for chemistry. 

B. Meddings and V. N. Mackiw, Gaseous Reduction of Metals from Aqueous Solutions, in Unit Processes in Hydrometallurgy, p. 354, Gordon and Breach, New York, 1964. 

In the broadest sense, coordination chemistry is involved in the majority of steps prior to the isolation of a pure metal because the physical properties and relative stabilities of metal compounds relate to the nature and disposition of ligands in the metal coordination spheres. This applies both to pyrometallurgy, which produces metals or intermediate products directly from the ore by use of high-temperature oxidative or reductive processes and to hydrometallurgy, which involves the processing of an ore by the dissolution, separation, purification, and precipitation of the dissolved metal by the use of aqueous solutions. 4... 

Some of the types of equilibria involved in the unit operations separation and concentration are listed in the introduction, Section 9.17.1. Those which depend most on coordination chemistry, and for which details of metal complex formation are best understood, are associated with hydrometallurgy. Once the metal values have been transferred to an aqueous solution, the separation from other metals and concentration can be achieved by one of the following processes.3... 

Urbanski, T. S. Fornari, P. Abbruzzese, C. Gold electrowinning from aqueous-alcoholic thiourea solutions. Hydrometallurgy 2000, 55, 137-152. 

Perez, O.P. Umetsu,Y. (2000) ORP monitored magnetite formation from aqueous solutions at low temperatures. Hydrometallurgy 55 35-56... 

Processes for extracting metals from their ores are generally classified as pyrometallurgical, if high temperatures are used, or hydrometallurgi-cal, if aqueous solutions are used. Copper is extracted by both methods. In the pyrometallurgical process for the extraction of copper, the enriched ore is roasted, or heated in air ... 

In the area of hydrometallurgy, Cu2+ and Au(CN)2 salts could be selectively sorbed from aqueous solutions with polyacrylamide-based copolymers containg aminoguanidine units. Porous copolymers of acrylonitrile, divinylbenzene and vinylacetate were derivated with aminoguanidine.15 Alternatively, methacrylate-based copolymers were transamidated with the same base16 to give polyacrylamide-type resins (Figure 11). 

Boyadzhiev L. Recovery of valuable metals from diluted aqueous solutions by creeping film pertraction. In Devis GA Ed. Separation Processes in Hydrometallurgy. London 1987 Pt. 3, Ch. 26 259-287. 

Martin TP and Davies GA. The extraction of copper from dilute aqueous solutions using a bquid membrane process. Hydrometallurgy 1977 2 315-334. 

KuUtami, P.S., Mukhopadhyay, S., Bellary, M.P., and Ghosh, S.K., Studies on membrane stability and recovery of uranium (VI) from aqueous solutions using a liquid emulsion membrane process. Hydrometallurgy, 2002, 64 49-58. 

Hydrometallurgy refers to the application of aqueous solutions for metal recovery from ores, and has been practiced for copper recovery for many years. The original impetus for solution methods for copper extraction before the development of froth flotation technology was the existence of large ore bodies of low copper content which were uneconomic to work using... 

Martin, T. P. Davies, G. A. "The Extraction of Copp>er from Dilute Aqueous Solutions Using a Liquid Membrane Process" Hydrometallurgy. 1977, 2,4, pp 315-334. 

Solvent extraction is a process that allows the separation of two or more components due to their unequal solubilities in two immiscible liquid phases. It is an important method in hydrometallurgy for separation of metal ions from their solution. The unique properties, such as good stability, nonvolatility, a wide liquid range, low flammability, and adjustable miscibility and polarity, the hydrophilic and hydrophobic depending on the structures of cations and anions, make ILs attractive as alternative media in liquid-liquid extraction of metal ions from aqueous solutions. 

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