Separation cobalt

It has been recently demonstrated that the simplest of the cobalt porphyrins (Co porphine) adsorbed on a pyrolytic graphite electrode is also an efficient electrocatalyst for reduction of 02 into 1120.376 The catalytic activity was attributed to the spontaneous aggregation of the complex on the electrode surface to produce a structure in which the cobalt-cobalt separation is small enough to bridge and activate 02 molecules. The stability of the catalyst is quite poor and largely improved by using porphyrin rings with mew-substitu-tion.377-380 Flowever, as the size of the mew-substituents increases the four-electron reduction efficiency decreases. 

Trinitro-triammino-cobalt, [Co(NH3)3(N02)3], was the first member of the series prepared. It is best prepared by treating a solution of eobaltous chloride with an ammoniacal solution of sodium nitrite and oxidising the mixture by means of air. The liquid after oxidation is allowed to stand for some days, when crystals separate these are filtered and washed with cold water to free them from chloride, and dissolved in hot water containing a little acetic acid. On cooling the acid liquid trinitro-triammine cobalt separates out, and later, from the same solution, the double salt, [Co(NH3)4(N02)2][Cb(NH3)2(N02)4], separates.1... 

Detection.—Dry Tests.—Salts of cobalt are usually of a rose-red colour when hydrated, and yield a beautiful blue colour in the borax bead test provided they are not present in excessive amount, otherwise the bead becomes opaque and appears black. When heated on charcoal with reduction mixture in the blowpipe test, metallic cobalt separates out in the form of small magnetic beads. When strongly heated with alumina a blue colour is produced, known as Thenard s blue. 

Y. Takata, F. Mizaniwa, and C. Mookoya. Electrocatalytic detection of cobalt separated by ion exchange chromatography. Anal. Chem., 51,2337,1979. 

Macrocycles. The influence of solvents and added solute molecules on the nature of associative species observed in solutions of the sodium salt of cobalt(ii)tetrasulpho-phthalocyanine has been investigated by electronic absorption spectrophotometry. Isolation of LCo2Br2,MeOH [LH2 = macrocyclic tetrakis SchifT base (10)] and its oxidation by Br2 to form LCo2Br3,2H20 has been reported. The crystal structure of the LCo2Br2,MeOH complex consists of a dinuclear unit with the two cobalts separated by 3.158(2) A and each cobalt is in an identical pseudo-square-pyramidal... 

Phenol hydroxylation over CoNiAl ternary fresh hydrotalcites yielded catechol and hydroquinionc with a preference to catechol. No other products were observed by GC indicating no transitory formation of p-bcnzoquinonc. This is in contrast to the results we have earlier reported for copper containing hydrotalcites (87, 105] where we observed both catechol and hydroquinone to significant levels, suggesting the nature of cations in the brucite-likc sheets in influencing the course of the reaction. Although both nickel and cobalt separately in a binary hydrotalcite with aluminum as trivalent cation showed no conversion of... 

Di (2-ethylhexyl) phosphate extraction agent, cobalt separation from chloride media... 

Basic violet 10 , 1-Nitroso-2-naphthol reagent, cobalt separation from chioride media Bis (2,4,4,-trimethylpentyl) phosphinic acid reagent, cobalt separation from sulfate media Bis (2,4,4,-trimethylpentyl) phosphinic acid reagent, cold permanent hair waves/strai g hteners Ammonium thioglycolate reagent, colored aluminum anodizing Maleic acid p-Phenol sulfonic acid 5-Sulfosalicylic acid reagent, colorimetric iron 5-Sulfosalicylic acid 5-Sulfosalicylic acid dihydrate... 

Zou Chunshan et al., Study on Cobalt Separation with Anion-exchange and CL-P204 Extraction Chromatography , Mining Metallurgy, 8(3) (1999),97-100. 

Flett, D. S. 1987. Chemistry of nickel-cobalt separation. In Extractive metallurgy of nickel, 76-97. New York John Wiley Sons. 

Skepper, I. G. and Fittock, J. E. 1996. Nickel cobalt separation by ammoniacal solvent extraction the operating experience. In Proceedings international solvent extraction conference, 777-782. Melbourne The University of Melbourne Press. 

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