Ruthenium minerals

In 1866 Friedrich Wohler discovered a ruthenium mineral. When he analyzed the shining black grains of what seemed to be an unusual platinum mineral which Herr Waitz of Cassel had brought back from Borneo, he found it to be a sulfide of ruthenium and osmium. Wohler stated that this mineral, which he named laurite, presented the first example of the natural occurrence of sulfur compounds of the platinum metals (129). 

Ketals of acetone and cyclohexanone with methyl, butyl, isopropyl and cyclohexyl alcohols are hydrogenolyzed to ethers and alcohols by catalytic hydrogenation. While platinum and ruthenium are inactive and palladium only partly active, 5% rhodium on alumina proves to be the best catalyst which, in the presence of a mineral acid, converts the ketals to ethers and alcohols in yields of 70-100% [933]. 

When recovered from the mineral osmiridium, the mineral is fused with zinc to convert it into a zinc alloy. The alloy is then treated with hydrochloric acid to dissolve the zinc away leaving a finely divided material. This finely divided sohd then is fused with sodium peroxide and caustic soda to convert osmium and ruthenium into their water-soluble sodium salts, sodium osmate and sodium iridate, respectively. While osmium is fully converted to osmate salt, most ruthemium and a small part of iridium are converted to ruthenate and iridate, respectively. The fused mass is leached with water to separate metals from sohd residues. 

The mineral osmiridium may alternatively be chlorinated at elevated temperatures on a bed of sodium chloride. Osmium is converted to water-soluble sodium chloroosmate. Iridium and ruthenium also are converted into water-soluble sodium chloroiridate and chlororuthenate. The insoluble residues are filtered out. Osmium is recovered from this solution in several steps as mentioned above. 

The initial steps are similar to any other mineral extraction process. This involves crushing mineral, froth flotation, gravity concentration and other steps to obtain platinum metal concentrates that may contain about 30 to 40 wt% of platinum group metals. The concentrate is treated with aqua regia to separate soluble metals, gold, platinum, and palladium from other noble metals such as ruthenium, rhodium, iridium, osmium, and silver that remain in... 

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 ... 

Bulk techniques still have a place in the search for presolar components. Although they cannot identify the presolar grain directly, they can measure anomalous isotopic compositions, which can then be used as a tracer for separation procedures to identify the carrier. There are several isotopically anomalous components whose carriers have not been identified. For example, an anomalous chromium component enriched in 54Cr appears in acid residues of the most primitive chondrites. The carrier is soluble in hydrochloric acid and goes with the colloidal fraction of the residue, which means it is likely to be submicron in size (Podosck el al., 1997). Measurements of molybdenum and ruthenium in bulk primitive meteorites and leachates from primitive chondrites show isotopic anomalies that can be attributed to the -process on the one hand and to the r- and /7-processes on the other. The s-process anomalies in molybdenum and ruthenium correlate with one another, while the r- and /7-process anomalies do not. The amounts of -process molybdenum and ruthenium are consistent with their being carried in presolar silicon carbide, but they are released from bulk samples with treatments that should not dissolve that mineral. Thus, additional carriers of s-, r-, and/ -process elements are suggested (Dauphas et al., 2002). 

The non-specific alkaline phosphatases present in bone and calcifying cartilage have several properties in common. The ATPases concerned in the formation of different hard tissues seem to be isozymes. It could be shown that two enzymes capable of degrading ATP exist. One of them can be inhibited by levamisole and R 8231 and is probably identical with non-specific alkaline phosphates. The activity of the other enzyme, tentatively named Ca-ATPase , is dependent on the presence of Ca2+ or Mg2+ and is activated by these ions. The Ca-ATPase is unaffected by ouabain and ruthenium red. It may be speculated that the Ca-ATPase is concerned with the transmembranous transport of Ca2+-ions to the mineralization front229. ... 

In a subsequent report, in 2005 [55], the same group described the preparation of imprinted polymer capable of oxidising alcohols and alkanes with 2,6-dichlor-opyridine /V-oxide (86) without mineral acid activation. The polymer was imprinted with a ruthenium porphyrin complex (87) using the diphenylmethana-mine (88) as pseudo-substrate template in order to achieve a shape of the cavity complementary to the substrates, diphenylmethane (89) and diphenylmethanol (84). The reaction, carried out with the imprinted polymer on the diphenylmethanol as substrate, showed a rate enhancement 2.5 higher than with the non-imprinted polymer. In the same conditions, but with diphenylmethane and... 

Mechanisms have been suggested for the N-bromosuccinimide (NBS) oxidation of cyclopentanol and cyclohexanol, catalysed by iridium(III) chloride,120 of ethanolamine, diethanolamine, and triethanolamine in alkaline medium,121 and for ruthenium(III)-catalysed and uncatalysed oxidation of ethylamine and benzylamine.122 A suitable mechanism has been suggested to explain the break in the Hammett plot observed in the oxidation of substituted acetophenone oximes by NBS in acidic solution.123 Oxidation of substituted benhydrols with NBS showed a C-H/C-D primary kinetic isotope effect and a linear correlation with er+ values with p = —0.69. A cyclic transition state in the absence of mineral acid and a non-cyclic transition state in the presence of the acid are proposed.124 Sulfides are selectively oxidized to sulfoxides with NBS, catalysed by ft-cyclodextrin, in water. This reaction proceeds without over-oxidation to sulfones under mild conditions.125... 

A model manure solution was prepared based on 10% glucose (as a carbohydrate hydrolysate model) with the various mineral components. The model solution was processed with three different catalyst formulations for comparison. The two nickel catalysts, ruthenium stabilized and copper stabilized (4), exhibited no effects from the contaminants, while the ruthenium showed reduced activity similar to that already noted. 

Davidson et al. [80] have used a ruthenium electrocatalyst to mineralize highly chlorinated and aromatic species such as chlorobenzene, penta-chlorophenol, and tetrachloroethylene, with minimum generation of secondary waste and efficient recovery of the ruthenium mediator. This system is similar to that of Ag(II), but it is not affected by the presence of the... 

Ruthenium occurs alloyed with platinum ores and osmiridium, as indicated in the tables of analyses (pp. 208, 258). Combined with sulphur it is found as the rare mineral laurite. Ru2S3,3 which occurs in platinum washings in Borneo and Oregon. That ruthenium is present in celestial bodies is evidenced by the fact that it was detected in the Perryville siderite discovered in 1906 (see this volume, Part II). 

Ruthenium Sesquisulphide, RuaSs, occurs in the platinum washings of Borneo and Oregon as the rare mineral lauriie, usually in the form of minute octahedra hardness 7-5, density 6-99. It has a bright metallic lustre and contains a little osmium. Deville and Debray 5 prepared a similar sulphide artificially in the form of isometric crystals, octahedra, and cubes by heating ruthenium with pyrites and borax. 

Metallic ruthenium is insoluble in the mineral acids, and is only slowly soluble in aqua regia. 

Perovskite structure the structure of the mineral CaTiOs Platinum metals the six platinum metals are ruthenium, rhodium, palladium, osmium, iridium, and platinnm Radiolysis decomposition of a compound by ionizing radiation such as X- or y-rays or a-particles Rutile structure the structure of the mineral rutile, a form of Ti02... 

The platinum-group metals consist of ruthenium, rhodium, palladium, osmium, iridium, and platinum. Each of the metals occurs naturally in its native form, and in economically exploitable deposits the elements occur overwhelmingly as individual platinum-group mineral (PGM) species. Mutual substitution of the various PGE is common, but substitutions in other minerals, such as base-metal sulfides, typically occur to only a limited extent. A comprehensive review of PGM and PGE geochemistry is given by Cabri (2002). 

Razina, I. S., Viktorova, M. E. Determination of submictogram amounts of osmium and ruthenium after separation by partition paper-chromatography. Metody AnaL Redkometal. Mineral. Rud. Gom. Rorod. 1, 53 (1971) C. A. 80, 33 582w (1974)... 

Like other members of the platinum family, ruthenium occurs in platinum ores. It is obtained from those ores and from the mineral osmir-idium by purification of the natural material. 

The use of palladium and ruthenium as halogen-free carbonylation catalysts has been studied intensively by Shell. The catalysts were principally designed for the carbonylation of olefins in the presence of alcohols in order to yield carboxylic esters [26], but work also well for the synthesis of carboxylic acids or anhydrides. The latter are formed when the reaction is conducted in an acid as a solvent [27]. The palladium systems typically consist of palladium acetate, tertiary phosphines, and strong acids such as mineral acids or acids with weak or noncoordinating anions such as p-toluenesulfonic acid. Remarkable activities are achieved when aromatic phosphines that carry pyridines as substituents are... 

Umemura, Y.. Yamagishi, A., Schoonheydt, R., Persoons, A., De Schryver, F. Langmuir-Blodgett films of a clay mineral and ruthenium(II) complexes with a noncentrosymmetric structure. J. Am. Chem. Soc. 124. 992-997 (2002)... 

Wet air oxidation in the presence of carbon-supported ruthenium provides an efficient method for total destruction by air of organic acid pollutants in aqueous solutions. In the presence of high concentrations of NaCl salts or of mineral acids, the oxidation of succinic acid was not modified, whereas the rate of oxidation of acetic acid formed transiently, was slightly lowered. In neutral and basic media, the oxidation of the carboxylate ions was greatly decreased. No leaching of ruthenium was observed, which means that the reaction was catalyzed by a heterogeneous catalytic system. However, the carbon support was partially oxidized, which limits the application of this catalytic system for the CWAO of acetic acid, which requires temperatures close to 200°C. 

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