Coal vanadium contents

In the United States, the largest concentration of atmospheric vanadium occurs over Eastern seaboard cities where residual fuels of high vanadium content from Venezuela are burned ia utility boilers. Coal ash ia the atmosphere also coataias vanadium (36). Ambient air samples from New York and Boston contain as much as 600—1300 ng V/m, whereas air samples from Los Angeles and Honolulu contained 1—12 ng V/m. Adverse pubHc health effects attributable to vanadium ia the ambieat air have aot beea deteroiiaed. lacreased emphasis by iadustry oa controlling all plant emissions may have resulted ia more internal reclamation and recycle of vanadium catalysts. An apparent drop ia consumption of vanadium chemicals ia the United States since 1974 may be attributed, in part, to such reclamation activities. 

The samples of the Eastern Interior Region considered here are those shown in Figure 1 west of the dashed north-south line in Illinois. All these samples are from Illinois beds 5 and 6. This selection was made to obtain a series of samples located at increasing distances from the source area of the sediments. Because the sedimentary source for the Indiana and Kentucky coal areas are less certainly known (6), the samples from those areas are not considered here. Except for beryllium and vanadium, the minor element content of samples from those areas is comparable to samples from western Illinois. The beryllium content of all these coals was reported by Stadnichenko and others (8). The unusually high vanadium content of some of the southern coals of the Eastern Interior Region is discussed below. 

Peter Zubovic. The coal is overlain by a black shale sequence which, in places, contains abundant pyritized marine fossils. Above the black shale there generally is a gray shale sequence. The thickness of the two units varies from place to place. The total thickness ranges from about 3-50 feet. I do not know the mineralogy of the shale. I suspect that there is a relation between the total thickness of the shale and the vanadium content of the coal. Parts of this area are being mapped at present, and in the near future we expect to have the data necessary to show if this suggested relation is valid. 

Fossil fuels frequently contain vanadium. Vanadium is found in almost all coals used in the United States, with levels ranging from extremely low to 10 g/kg (Byerrum et al. 1974 WHO 1988). Eastern U.S. coal has an average content of 30 ppm, western coal has an average content of 15 ppm, and coal from the interior contains an average of 34 ppm (Byerrum et al. 1974). The average vanadium content of bituminous and anthracite coal is 30 ppm and 125 ppm, respectively (Byerrum et al. 

Another source of vanadium, of interest in biological and environmental contexts, are fossil fuels such as peat, coal, bitumen, oil-shales, asphalts and crude oil. The vanadium content of hard coal can vary from 0.007 to 0.34%. Crude oil from Albania (0.034%), the Volga-Ural region (0.061%) and Venezuela (0.12%) (upper limit in all three cases) is particularly rich in vanadium.I l A high vanadium content is often associated with high sulfur contents. The reasons for the notable enrichment of vanadium in fossils compared with bio-mass precursors such as bacteria, protozoans, algae, plants and animals are still under debate. Possible mechanisms for a secondary input of vanadium in decaying... 

There is little resemblance between the mineral content of coal and fuel oil so that the fouling in each combustion process will be very different. Much higher proportions of sodium are encountered in fuel-oils than coal with relatively high vanadium contents (vanadium is virtually never present in coal). The total mineral content of oil is likely to be as low as 0.1% of the oil substance whereas the mineral content of some poor quality coal can be as high as 50%. Table 16.11... 

Applications to neutron activation analysis constitute another important use of Cf neutron sources. Neutron capture in many elements forms radioactive species that then decay with highly characteristic gamma-ray emissions. This analytical procedure is very sensitive and specific, and is widely used for the analysis of trace elements. Neutron activation finds use in uranium borehole logging to make accurate determinations of the uranium concentrations in boreholes as little as 100 parts per million of UaOg can be detected by this procedure. Other industrial uses for Cf sources are in the continuous monitoring of the sulfur and ash content of coal on a moving conveyor belt at the rate of SO tons per hour. Batch analysis of the vanadium content of crude oil is still another application of neutron activation analysis. 

One of the more important considerations in determining the end use of synthetic graphite is its contamination with metallic components Metals such as iron, vanadium, and especially in nuclear applications, boron are deleterious to the performance of graphite Table 3 presented the extraction yields of NMP-soluble material for three bituminous coals. For these coals, mineral matter and insoluble coal residue were separated from the extract by simple filtration through 1-2 pm filter paper fable 13 lists the high-temperature ash content in the dry coal, and in their corresponding NMP-insoluble and NMP-soluble products. The reduced ash content of the extract is typically between 0.1 to 0.3 wt% using traditional filtration techniques for the small-scaled extraction experiments... 

Approximate contents of 14 minor and trace elements in oils produced from three coals by the catalytic hydrogenation process of Gulf Research and Development Co. were determined by emission spectroscopy. The results were compared with corresponding data for the original coals and the solid residues from the process. The contents of ash, sulfur, vanadium, lead, and copper are near or below the limits specified for an oil to be fired directly in a gas turbine while sodium and probably calcium are too high. Titanium appears to be somewhat enriched in the oils analyzed relative to other elements, suggesting its presence in organo-metallic complexes. 

Another test method for the determination of mercury in coal (ASTM D-6414) involves (method A) solubilizing of the mercury in the sample by heating the sample at a specified temperature in a mixture of nitric and hydrochloric acids. The acid solutions produced are transferred into a vessel in which the mercury is reduced to elemental mercury. The mercury vapor is determined by flameless cold-vapor atomic absorption spectroscopy. An alternative method (method B) involved solubilization of the mercury by heating the sample in a mixture of nitric acid and sulfuric acid with vanadium pentoxide. The acid solution is then transferred into a vessel in which the mercury is reduced to elemental mercury. The mercury content is determined by flameless cold-vapor atomic absorption spectroscopy. However, mercury and mercury salts can be volatilized at low temperatures, and precautions against inadvertent mercury loss should be taken when using this method. 

Emissions from coal-fired power plants have been the subject of intensive study by many workers (27,28,29,30). However, oil-fired power plants also can be expected to emit trace metals. A comparison of the approximate metal content of typical coals and oils given in Table VIII indicates that oils contain at least 13 of the important metals with high (> 10 ppm) concentrations of vanadium, zinc, and nickel. Coal contains at least 14 of the environmentally important metals with very high (> 100 ppm) concentrations of iron, magnesium, titanium, and zinc. 

However, there were two unfavorable aspects. First, the amount of SO emissions was significantly larger than that of commercial heavy fuel oil and low sulfur coal. Second, the high content of heavy metals such as vanadium could produce severe corrosion in the boiler chamber (61, 63). Fortunately, both problems eould be corrected by means of aheady existing technologies, such as flue-gas desulfurization, and by the addition of small amounts of magnesium salt. This last forms a noncorrosive solid precipitate with vanadium that can be easily removed. 

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