Cobalt ions minerals

The present method is still in its early stage of application. Both ex situ and in situ type measurements are applicable to a variety of mineral/aqueous solution interfaces. For example, the mechanism of selective adsorption of cobaltous ions on manganese minerals can be studied by this method. In addition to the two Mossbauer source nuclides described in the present article, there are a number of other nuclides which can be studied. We have recently started a series of experiments using Gd-151 which is a source nuclide of Eu-151 Mossbauer spectroscopy. Development of theory on surface magnetism, especially one including relaxation is desirable. Such a theory would facilitate the interpretation of the experimental results. 

It is known that non-aqueous synthesis has been effectively applied in the preparation of various metal phosphates, including amine-containing aluminum, gallium, indium, zinc and cobalt phosphates with three-dimensional open-framework structures [17-24]. Moreover, phosphates with a layered or chain structure can been crystallized from non-aqueous media [25, 26]. Since the fluoride ions mineralizer was introduced into the synthesis of zirconium phosphates, several zirconium phosphate fluorides with novel structures have also been developed. 

Trace element Minerals, such as copper, iron, zinc, and cobalt ions, that are required in minute amounts for growth. 

Cobalt is the thirtieth most abundant element on earth and comprises approximately 0.0025% of the earth s cmst (3). It occurs in mineral form as arsenides, sulfides, and oxides trace amounts are also found in other minerals of nickel and iron as substitute ions (4). Cobalt minerals are commonly associated with ores of nickel, iron, silver, bismuth, copper, manganese, antimony, and 2iac. Table 1 Hsts the principal cobalt minerals and some corresponding properties. A complete listing of cobalt minerals is given ia Reference 4. 

Despite the above similarities, many differences between the members of this triad are also to be noted. Reduction of a trivalent compound, which yields a divalent compound in the case of cobalt, rarely does so for the heavier elements where the metal, univalent compounds, or hydrido complexes are the more usual products. Rhodium forms the quite stable, yellow [Rh(H20)6] " ion when hydrous Rh203 is dissolved in mineral acid, and it occurs in the solid state in salts such as the perchlorate, sulfate and alums. [Ir(H20)6] + is less readily obtained but has been shown to occur in solutions of in cone HCIO4. 

The adsorption of transition metal complexes by minerals is often followed by reactions which change the coordination environment around the metal ion. Thus in the adsorption of hexaamminechromium(III) and tris(ethylenediamine) chromium(III) by chlorite, illite and kaolinite, XPS showed that hydrolysis reactions occurred, leading to the formation of aqua complexes (67). In a similar manner, dehydration of hexaaraminecobalt(III) and chloropentaamminecobalt(III) adsorbed on montmorillonite led to the formation of cobalt(II) hydroxide and ammonium ions (68), the reaction being conveniently followed by the IR absorbance of the ammonium ions. Demetallation of complexes can also occur, as in the case of dehydration of tin tetra(4-pyridyl) porphyrin adsorbed on Na hectorite (69). The reaction, which was observed using UV-visible and luminescence spectroscopy, was reversible indicating that the Sn(IV) cation and porphyrin anion remained close to one another after destruction of the complex. 

These hydroxo-salts are all sulphur-yellow crystalline substances. The acid residues are hydrolysable and hence outside the co-ordination complex, and the aqueous solutions, unlike the hydroxo-salts of chromium-and cobalt-ammines, are neutral to litmus, a fact which Werner suggests is due to the smaller tendency of the hydroxo-radicle attached to ruthenium to combine with hydrogen ions. This tendency is much less than in the case of the ammines of cobalt and chromium, but that it still exists is indicated by the increased solubility of these hydroxo-compounds in water acidified with mineral acids, and from such solutions aquo-nitroso-tetrammino-ruthenium salts are obtained thus ... 

What do the ions of the following elements have in common calcium, Ca chlorine. Cl chromium, Cr cobalt, Co copper, Cu fluorine, F iodine, I iron, Fe magnesium. Mg manganese, Mn molybdenum, Mo nickel, Ni phosphorus, P potassium. K selenium, Se sodium, Na sulfur, S zinc, Zn They are all dietary minerals essential for good health, but can be harmful, even lethal, when consumed in excessive amounts. 

An enzyme cofactor can be either an inorganic ion (usually a metal cation) or a small organic molecule called a coenzyme. In fact, the requirement of many enzymes for metal-ion cofactors is the main reason behind our dietary need for trace minerals. Iron, zinc, copper, manganese, molybdenum, cobalt, nickel, and selenium are all essential trace elements that function as enzyme cofactors. A large number of different organic molecules also serve as coenzymes. Often, although not always, the coenzyme is a vitamin. Thiamine (vitamin Bj), for example, is a coenzyme required in the metabolism of carbohydrates. 

Salt. When compared on a molar basis, the mineral ion salts (ammonium, calcium, rubidium, copper, silver, lead, manganese, cobalt, potassium, and sodium, and cyclohexylamine salt) were as effective as the free gibberellic acid in promoting stem elongation (10,14). As shown in Figure 1, the potassium and zinc salts of A3 were as active as the acid in promoting the growth of d-1 dwarf maize. 

In aluminosilicates each high-spin trivalent transition metal ion has a larger ionic radius than the host Al3+ ion. However, cations such as Cr3+ (-249.9 kJ/mole), V3+(-182.8 kJ/mole) and Mn3+ (-150.8 kJ/mole), which acquire particularly large CFSE s in octahedral coordination (table 2.5), are induced to enter [A106] octahedra, and not five-coordinated [A105] (andalusite, yoderite) or tetrahedral [AlOJ (silhmanite) sites, by the enhanced stabilization bestowed in octahedral crystal fields. Although Co3+ ions have not been positively identified in silicate minerals, the strong enrichment of cobalt in natural and syn-... 

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