Electrolytic extraction

USSR 76 and Brazil 37 tonnes of contained Be, which together accounted for 98% of world production. The cost of Be metal was 690/kg in 1987. By contrast, world supplies of magnesium are virtually limitless it occurs to the extent of 0.13% in sea water, and electrolytic extraction at the present annual rate, if continued for a million years, would only reduce this to 0.12%. 

We have already described the refining of copper and the electrolytic extraction of aluminum, magnesium, and fluorine. Another important industrial application of electrolysis is the production of sodium metal by the Downs process, the electrolysis of molten rock salt (Fig. 12.15) ... 

Chemical separation may be considered (acid treatment, leaching) when the parts to be removed are more reactive than the compound to be isolated and can be dissolved and washed away. A special case may be the electrolytic extraction when, in a solidified sample, there is sufficient electrochemical difference between the various phases an example is the extraction from Al-rich ingots of compounds such as CrAl7 and MnAl6 (Raynor and Wakeman 1947). 

Uses. Manufacture of rayon, mercerized cotton, soap, paper, aluminum, petroleum products metal cleaning electrolytic extraction of zinc tin plating oxide coating... 

The electrolyte extractants (NH4NO3, NaCl, MgC, CaC ) displaced only about half of the sorbed ions (with less from HA I than HA II), which indicates that a higher proportion of Cu and Pb ions become coordinated to the organic solid. 

Jumau s process (ut supra) for the electrolytic extraction of copper from its ores is also applicable to the production of pure copper from solutions of its compounds.8 The cupric sulphite or cupro-cupric sulphite precipitated from the copper solution by the action of sulphurous acid or a sulphide is decomposed by sulphuric acid into cupric sulphate and metallic copper. The metal thus liberated is pressed into a form suitable for an anode, and refined electrolytically. 

However, in many situations, water is hardly the ideal solvent. Take the electrolytic production of sodium metal, for exanple. If an aqueous solution of a sodium salt is taken in an electrolytic cell and a current is passed between two electrodes, then all that will happen at the cathode is the liberation of hydrogen gas there will be no electrodeposition of sodium (see Chapter 7). Hence, sodium cannot be electrowon from aqueous solutions. This is why the electrolytic extraction of sodium has taken place from molten sodium hydroxide, i.e., from a medium free of hydrogen. This ... 

Recovery of RMFP by catalytic electrolytic extraction (Step I-B)... 

Electrolysis has been applied primarily to extract metallic Re from solutions, and to produce Re coatings. In electrolytic extraction, the metal can be obtained in the form of a bright deposit or a black powder, depending on the conditions of electrolysis. The... 

Samples of electrolyte extract and residual BZ obtained during the partial oxidation of BZ by Ag(n) were injected onto a 30 m long Quadrex 007 (methyl silicone) column or a 25 m long DB-1 column. Both columns had inside diameters of 0.25 mm and film thicknesses of 0.25 )l.m. The head pressure and injection port temperature were maintained at 5 psi and 250°C, respectively. After injection of 2-3 p.L of sample, the temperature of the column was held at 40°C for 10 min and then ramped at a rate of 4°C/min to 300°C. 

Izart, On Electrolytic Extraction of Antimony from Ores, L Electricien,... 

Man] Residual electrolytic extraction 950-1225°C multi-component alloy... 

Takl] Electrolytic extraction, optical microscopy. X-ray diffraction < 50 at.% W... 

KUO] [1953KUO] Electrolytic extraction. X-ray diffraction (Guinier technique) 700°C, < 9.56 mass% W, < 0.32 mass% C... 

Ueltz, H.F.G. (1960) Electrolytic extraction of refractory metals of groups IV, V, and VI from their Carbide. US Patent 2,910,021. 

Anodic Decomposition of Toxic Compounds (Anodic Mineralization), Fig. 4 ESR signals of electrolyzed carbonate solution containing 20 mM phenol. The number is elapsed times (min) after the addition of DMPO (radical trapping reagent) to the electrolyte extracted from the cell... 

The strong influence of the inner solution composition on the resulting calibration curves is shown in Fig. 9.21. A very high detection limit can be obtained in practice with concentrated and lipophilic electrolytes that result in substantial electrolyte extraction into the back side of the membrane (here, c (5 ) = 0.02M). The predominant mode of transport is then co-diffusion with its cotmterion. 

Scheme 4.2 Model of the surface interactions between nanosized AI2O3 particles and the PEO-UCF3SO2 electrolyte, extracted from Croce...

Aluminium is the most abundant metallic element in the Earth s crust. It is extracted by purifying bauxite, an impure hydrated oxide, which may be represented as AI2O3.3H2O, and the subsequent electrolytic extraction of the metal. Many of the uses of aluminium — in canning, aircraft construction, and overhead transmission lines — depend on its low density and resistance to corrosion in air and water. This resistance is a kinetic effect, caused by a coherent oxide film, which protects the underlying metal. Some of the important aluminium chemistry that we discuss is summarized in Figure 9.16. 

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