Separation Of Platinum Metals Research Articles

Trends in Sorption Recovery of Platinum Metals: A Critical Survey

The major trends in research into the sorption recovery and separation of platinum metals are critically surveyed. The advantages and disadvantages are described for ion-exchange and complexing sorbents based on organic polymers, chemically modified silicas, sorbents with applied macrocyclic compounds, hybrid organomineral sorbents with supported polymers, molecular imprinted sorbents, solid-phase extractants based on ionic liquids, biosorbents, and other types of sorbents. The technological potentials of these sorbents are evaluated.

Binary Extraction in Hydrometallurgy

Results obtained during technological application of binary extraction (extraction by salts of organic acids and organic bases) for recovery and separation of non-ferrous, rare, noble and associated metals are presented in the paper. The method of extraction of copper, especially from leaching solutions of oxidised ores, with the use of tertraoc-tylammonium dialkyldithiophosphate has been developed- The binary extractant is characterized by high separation coefficients of copper and iron, large capacity according to copper and high rate of its extraction and stripping by solutions of ammonia. The technology has also been tested in the sorption-extraction mode. Possibilities of the use of binary extractants for the purification of sulphate solutions containing copper and iron, and also chloride solutions containing iron, have been discussed. The technological scheme developed for the purification of aluminium from iron in chloride solutions with the application of carboxylate of trialkylamine is characterized by a more concentrated strip solution obtained in comparison with the system based on trialkylamine. The technology of the extraction of indium from Zn-containing sulphate solutions with the use of binary extraction by dialkylphosphate of trioctylamine has been developed and adopted at the Chetaybinsk zinc factory. The use of hydrochloric acid has been avoided in the stripping stage by the application of binary extractant. The technological scheme worked out for the extraction of cadmium from Zn-containing sulphate solutions with the use of carboxylate of trialkylamine allows one to achieve objectives of cadmium recovery in the form of chloride anion, cadmium concentration and conversion with the generation of cadmium sulphate solution suitable for cementation and also simultaneous purification of zinc sulphate solution from chloride ion with the production of concentrated solution of natrium chloride. Possible uses of binary extractants for the recovery of molybdenum as well as extraction and separation of platinum metals are also discussed. In hydrometallurgy the extraction processes are most effectively applied to solve the following tasks: •extraction (and usually simultaneous concentration) of valuable components in processing solutions with complex composition; - separation of elements with similar properties and their isolation into corresponding products; •purification of aqueous technological solutions from elements - impurities; synthesis of inorganic compounds using, stripped solutions with definite element composition; •purification of industrial sewage. Obviously, an extractant is selected depending on the objectives. A search of extractants is a continuing process and a wide circle of specialists in the field of extraction chemistry and technology, organic synthesis, physical chemistry, and others take part inthis process. Recently processes of the so-called binary extraction have attracted re- searcher's attention considerably. A review of results obtained by us on the use of binary extraction for technological applications is given in the present paper.

Reactive polymers, 53. separation of platinum metals on the copolymer of glycidyl methacrylate—ethylene dimethacrylate modified with ethylenediamine

AbstractA macroporous copolymer of glycidyl methacrylate — ethylene dimethacrylate, modified with ethylenediamine, is able to bind only ionic particles (PdCl4)2− from strongly acid solutions containing palladium‐ and copper salts. After washing the sorbent, the metal can be quantitatively desorbed with a concentrated hydrochloric acid solution. The procedure can be utilized for the regeneration of inactive palladium catalysts in industry. Moreover, using the same sorbent and the same principles, it is possible to separate a mixture of platinum metals in acid solutions as (RhCl6)3−, (PtCl6)2−, and (PdCl4)2− by eluting them with a solution of hydrochloric or nitric acid with increasing concentration, the efficiency being 100%.

Separation of Platinum Metals by Paper Electrophoresis

Abstract Ruthenium, rhodium, palladium, osmium, indium and platinum have been separated from a single spot in horizontal paper electrophoresis using ethylenediaminetetraacetic acid (EDTA) as background electrolyte. Electrograms were run using 0.01 M electrolyte, at pH 9.0, 10.5, 11.0 and 12.0. Binary, ternary, quaternary and quinary separations are possible at various pH values, but best separation occurs at pH 11.0. At this pH, ruthenium and osmium slightly overlap with each other and can be separated by cutting this zone and placing it on a fresh paper and carrying on the electrophoresis, now using 0.1 M EDTA at pH 6.0. Ruthenium and osmium can thus be separated from each other on the second paper. The temperature is kept at 20°C, a potential 250 V is supplied, and the developing time is 3.5 hr.

Paper chromatography in the separation of platinum metals

The separation of micro amounts of Ru +3, Rh +3, Pd +2, Os +4, Ir +4, Pt +2, Pt +4, and Au +3 with as many as 48 different solvent mixtures in the presence or in the absence of a complexing, oxidizing, and reducing agent is described. A maximum resolution of five of the ions are possible from a mixture of the components. The results are discussed and typical separations are presented.