Cobalt glance

More than 200 ores are known to contain cobalt but only a few are of commercial value. The more important are arsenides and sulfides such as smaltite, C0AS2, cobaltite (or cobalt glance), CoAsS, and linnaeite, C03S4. These are invariably associated with nickel, and often also with copper and lead, and it is usually obtained as a byproduct or coproduct in the recovery of these metals. The world s major sources of cobalt are the African continent and Canada with smaller reserves in Australia and the former USSR. All the platinum metals are generally associated with each other and rhodium and iridium therefore occur wherever the other platinum metals are found. However, the relative proportions of the individual metals are by no means constant and the more important sources of rhodium are the nickel-copper-sulfide ores found in South Africa and in Sudbury, Canada, which contain about 0.1% Rh. Iridium is usually obtained from native osmiridium (Ir 50%) or iridiosmium (Ir 70%) found chiefiy in Alaska as well as South Africa. 

Brandt published a description of this mineral in the volume of the Acta of die Upsala Academy for 1742 and in Vetenskapsacademiens Handlingarna for 1746, and mentioned that it contains cobalt, iron, and sulfur, but that, unlike ordinary cobalt glance, it is free from arsenic. When W. von Hisinger made a quantitative analysis of it m 1810, he found it to be cobalt sulfide. This mineral is now known as linnaeite its formula is CosS4, in which part of the cobalt may be replaced by nickel, iron, or copper. 

Cobaltite (Cobalt glance) CoS2.CoAs2 5 5 6-0 to 6-3 Cubic, pyritohedral 42 5 to 45-5... 

Cobalt bloom. Cobalt glance. Cobaltite See Erythrite See Cobaltite CoAsS Silver- 6-2 6-5 Cubic... 

Examination of the Egyptian material led to a further discovery. The general Nile pattern, produced by Nile muds and the ceramics made from it, is on first glance very close to that of the Palestinian red field clay. When the plots of three clays and six sherds were matched by the scandium—iron points, cobalt, chromium, and europium also matched exactly. Thus in the Nile samples, concentrations of the five elements are highly mutually correlated. This observation then allowed detection of subtle differences between Palestinian and Egyptian materials. The... 

At a first glance it seems that the special properties of M-C bonds are not involved in biological systems. The well-known coenzyme B12, in which a cobalt-... 

The rate trend in the first three complexes might, at first glance, be attributed to steric hindrance to attack on cobalt by the incoming water molecule, but we know from many eases observed in organic chemistry that if steric hindrance of this sort operates, the effects are generally... 

Cloddy, from Friberg Glance, containing Cobalt and Arsenic. 

Bismuth is seldom found in its elemental state (as a pure metal) in the earth. Its compounds are generally found along with ores of other metals, such as lead, silver, gold, and cobalt. The most important mineral of bismuth is bismuthinite, also known as bismuth glance (Bi2S3). 

Bismuth is a relatively rare element and ranks 64th in abundance in the earth s crust, which is estimated to contain 0.17-0.2 ppm of bismuth. This is comparable in abundance to silver and cadmium. Bismuth content increases from ultrabasic (1 X 10 %) to acid magmatic rock (1 X 10 %) and is not concentrated in the magmatic phase. Native bismuth is rarely found in nature in cobalt and silver veins, but usually occurs as the compounds, mostly sulfide (bismuthinite or bismuth glance, Bi2S3) together with complex minerals asso-... 

An example of this is shown in Fig. 2.7. The object here is a smoke cobalt particle prepared by gas evaporation in an inert-gas atmosphere. No contrast can be seen in electron micrograph (a) which represents the electron intensity distribution. However, circular contour fringes appear in contour map (b). Since the phase distribution is amplified twice, these contour lines indicate magnetic lines of force in h/2e units. It can be seen at a glance how magnetic lines of force rotate in such a fine particle. The principle behind this technique is the same as that of a fiux-meter SQUID except that its sensitivity h/e rather than h/2e as in a SQUID. Therefore, we may call an electron interferometer a SQUID in a microscopic world . 

Table 2 summarizes the electrode potentials of the electron transfers cited. At first glance it is not easy to discern an unequivocal trend in redox propensity after changing the metal atom, in that the substitution of one iron atom for one cobalt atom in [Fe3(CO)9(/<3-S)] results in the electron-transfer capacity changing from oxidation to reduction. Nevertheless, if, as indicated, one takes into consid-... 

At a first glance, cobalt and iron are similar FT-catalysts with both, waxes, diesel fuel, gasoline and LPG can be obtained. Mainly the reaction temperature controls the probability of chain prolongation pg. High values of Pg are noticed at low temperature (ca. 190 - 230°C). This corresponds to the general trend for the hydrocarbon-intermediates the increase of desorption probability with increasing temperature [16]. 

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