Separation copper

The alloy aluminium-4 wt% copper forms the basis of the 2000 series (Duralumin, or Dural for short). It melts at about 650°C. At 500°C, solid A1 dissolves as much as 4 wt% of Cu completely. At 20°C its equilibrium solubility is only 0.1 wt% Cu. If the material is slowly cooled from 500°C to 20°C, 4 wt% - 0.1 wt% = 3.9 wt% copper separates out from the aluminium as large lumps of a new phase not pure copper, but of the compound CuAlj. If, instead, the material is quenched (cooled very rapidly, often by dropping it into cold water) from 500°C to 20°C, there is not time for the dissolved copper atoms to move together, by diffusion, to form CuAlj, and the alloy remains a solid solution. 

Rajakovic, L.V. (1992) The sorption of arsenic onto activated carbon impregnated with metallic silver and copper. Separation Science and Technology, 27(11), 1423-33. 

Narr, E., Godt, A., andjeschke, G. (2002). Selective measurements ofa nitroxide-nitroxide separation of 5 nm and a nitroxide-copper separation of 2.5 nm in a terpyridine-based copper(II) complex by pulse EPR spectroscopy. Angew. Chem. Int. Ed. Engl. 41, 3907-3910. 

On stirring a mixture of a few cubic centimetres of a solution of titanous sulphate and one litre of a 0-01 per cent, solution of cupric sulphate, metallic copper separates after an interval of a few minutes. Most of the finely divided metal passes through a filter-paper, the colour of the solution being blue by transmitted light, and copper-red by reflected light. The reaction affords a sensitive test for copper, since by its aid one part of the metal can be detected in one million parts of solution.3... 

Winkelmann used two concentric brass cylinders with the liquid in the intervening space, the whole being immersed in ice, and the temperatures of the inner cylinder was determined (see 4.VIIG). Weber used the fito method tried by Guthrie, the liquid being contained between two circular discs of copper separated by three thin glass spacers. The lower plate was put in contact with ice, and the fall in temperature of the upper plate followed by a thermocouple with one junction soldered to the plate. This method was... 

Ammonia complexation has also been employed, primarily for nickel-copper separations but also for copper recovery, when this is from native copper or copper oxide ores [15]. The dissolving process is thought to involve formation of soluble cuprous ammonium carbonate [53] (Eqs. 13.51 and 13.52). 

Hydroxyamme polymers have also been explored extensively. Vemon and Eccles have prepared several hydroxyoxime-type polymers and recommended their use for copper separation from iron at low pH value. Amidoxims-ty pa functional groups are fonnd to chelate uranium at low concentrations in senwater and to offer a potential solution to the problem of separating henvy metals from acidic solutions. 

To improve conductivity in the electroplating of automobile bumpers, a thin coating of copper separates the steel from a heavy coating of chromium. 

The conditions of copper separation from mixed copper/zinc ores of various compositions are different [154]. While the optimum potential for mineral separation from the difficult ore chalcopyrite was +50 to + 150 mV, the separation of the copper mineral sphalerite from mixed ores required a negative potential of about -150 mV. In all cases, xanthogenates and dithiophosphates were used as agents. 

Frangois J.P., Gijbels R., Hoste J. A radiochemical study of the fire assay of rhodium with copper and the subsequent rhodium-copper separation. Talanta 1974 21 780-783. 

Copper impurities at the concentration level 10 " M in plating baths can cause deterioration of the physical properties of coatings.Several analytical methods of determination of copper in presence of very large excess of other heavy metals are available but they are usually time consuming and susceptible to errors due to necessity of preliminary copper separation. 

The reaction of the diprotonated cryptand (16) with Cu(CH3CN)4Bp4 in methanol gave a dinuclear copper(I) complex (18) of the neutral cryptand. The X-ray crystal structure of this complex (Fig. 12b) shows that both the integrity of the cryptand and the unusual trans-trans conformations of the dicarbimine functions found in the protonated ciwptand are retained in the structure of the complex. The Cu(I)...Cu(I) separation is 6.25A. This copper separation is well in excess of that reported, 3.04A, for the dicopper(I) complex, [L Cu2](C104)2, in which is the [3+2] Schiff base cryptand derived from 2,6-... 

Fern, J H and Shaw, R W, 1983. Copper separation and recovery at the BHAS lead smelter. Port Pirie, South Australia, in Proceedings MMIJ - The Australasian Institute of Mining and Metallurgy Joint Symposium, Sendai. 

Anodes are cast from smelter bullion after copper separation and partial softening if needed, either in flat open moulds on a casting wheel as a measured amount, or into closed book moulds . One critical aspect of the performance of the anode is that it should dissolve at a uniform rate and this can be influenced by the microstructure and uniformity of the anode as well as by the impurity content. In this regard the casting method and the cooling rate are most important, and the use of book moulds is preferable in achieving better control and uniformity of the surface structure. With an open mould as in wheel cast anodes, the upper and lower surfaces are quite different in terms of crystal structure, oxidation and flatness. 

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