Mixture Of CoO Research Articles

Precipitation of Thorium or Uranium(VI) Complex Ion with Cobalt(III) or Chromium(III) Complex Cation, (II)

The precipitations of thorium and uranium(VI) sulfito complex ions with hexammine cobalt(III) chloride as the precipitant have been studied. The orange-colored uranium(VI) precipitate obtained is [Co(NH3)6]4[UO2(SO3)3]322H2O, which is in the form of square bipyramid, about 4 μm across in a cubic symmetry of the diamond type with a=10.40A It decomposes to an oxide mixture of Co3O4 and U3O8 above 850°C in the air through a sulfate mixture of CoSo4 and UO2SO4. Composition of the thorium precipitate varies with the precipitation conditions. Therefore, it is considered that the thorium precipitate contains thorium hydroxide and basic thorium sulfite.

Heterogenite from Naganobori Mine, Yamaguchi Prefecture, Japan

The first occurrence of heterogenite in Japan is descrived. The mineral occurs as irregular masses, 0.1 to 3cm in diameter, in the oxidation zone of the Naganobori metasomatic cobalt-copper deposit, Yamaguchi Prefecture, associated with goethite, montmorillonite, quartz, malachite and etc. Color steely black, luster dull to submetallic, streak iron gray. Cleavage none. D 3.1-3.4, Vickers hardness 217 (weight 100 gr.). Chemical analysis data coresponds closely to the formula of (Co, Cu) (O, OH)•OH. X-ray study shows the mineral to be rhombohedral with a0 4.72_??_;, α 35°14'. The high-temperature x-ray diffraction and DTA indicate the mineral with some impurities changes to the mixture of CoO, Co3O4, CoFe2O4 and Co2SiO4 at about 1, 000°C.

Hermochemistry of the Co-S-O System Rom 950 to1200°K

AbstractTotal pressures prod. by the decom of CoSO4 and by the decomp of mixtures of CoO and Co3O4 were measured, using a Pyrex bellows mercury manometer. At temp in excess of 782°C, in the presence of its gaseous decomp products, CoSO4 produces CoO. At temp < 782°C. the oxide product is a mixture of CoO an Co3O4. Perhaps because of the high surface energy of the finely divided oxides, an irreversible metastable equilibr can be observed during the initial of an experiment for the measurement of the O presuure over mixtures of CoO and Co3O4.Free energies for the sulphate and oxide decomp reaction were combined with published data on CoO, CoS, Co9S8,SO3 and SO2 to produce thermodynamic phase diag for the various univariant and bivariant equilibria existing between 950 and 1200°K.The transition from β to a CoSO4 occurs at 675 ± 10°C and involves 0.60 ± 0.04 kcal/mole.