Trace-Element Geochemistry of Coal Resource Development Related to Environmental Quality and Health (1980) / Chapter Skim
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THE RESOURCE AND ITS UTILIZATION
THE RESOURCE AND ITS UTILIZATION
Pages 11-38
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From page 11... ...
The coal is often interbedded with shale, sandstone, and other sedimentary rocks. A single stratigraphic sequence may include several coal beds; 117 different coal beds have been identified and named in West Virginia alone.
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From page 12... ...
However, in the United States the western low-rank coals tend to contain less sulfur than the higher-rank midwestern and eastern bituminous coals. together with some remaining plant materials remain as ash when the coal is burned.
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From page 13... ...
Younger lignitic and subbituminous coals occur principally in Montana, Wyoming, North Dakota, and the Gulf Coast states. As shown in Figure 5, coal-bearing rocks underlie about 14 percent of the land area of the contiquous United States.
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From page 14... ...
This report reflects the foregoing use pattern in concentrating on the mobilization of trace elements from electric power production. TABLE 2 Proportion of Total Production and Typical Heating Values of Coala Production Heatin2 Value Rank (percent)
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From page 16... ...
whereas the same trace elements emitted to the atmosphere in an uncontrolled manner could have strong negative environmental effects. The maximum amount of a particular element that might be mobilized into the environment from coal mining and use could be estimated from data on the total major, minor, and trace-element content of coal.
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From page 17... ...
Therefore, the concentration of inorganic elements, as both mineral matter and organically combined species, varies from one location to another in a coal bed and from one bed to another. Typical compositional values are shown in Table 6, but it should be clearly understood that any given coal seam may contain concentrations of specific elements that deviate significantly from these values.
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From page 18... ...
Geological Survey in the National Coal Resources Data System (Carter, 1976)
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From page 19... ...
0.002 0.01 0.006 0.015 0.01 0.005 Titanium (Ti) 0.15 0.08 0.05 0.12 0.08 0.05 Minor and trace elements (ppm)
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From page 20... ...
TABLE 7 Enrichment Factors of Trace Elements in ~oal with Respect to the Average Composition of the Earth's Crusta, Limited Enrichment Moderate Enrichment Marked Enrichment Element Enrichment Element Enrichment Element Enrichment Hg 2.25 As 8.3 Se 82 Mo 2.00 Cd 6.5 Pb 1.28 B 5.0 Sb 5.5 aRefer to coal composition in Table 6. b The average chemical composition of the Earth's crust was taken from data reported by Taylor (1964)
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From page 21... ...
cAverage sulfur and nitrogen calculated from analysis of 158, 90, 19, 40, 86, and 9 samples from Appalachian region, Interior province, Gulf province, Northern Great Plains province, Rocky Mountain province, and Alaska, respectively. Averages of the remainder of the elements were calculated from the analysis of 331, 143, 34, 93, 124, and 18 samples from the Appalachian region, Interior province, Gulf province, Northern Great Plains province, Rocky Mountain province, and Alaska, respectively.
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From page 22... ...
Elemental concentrations tend to be hiqher in eastern coals, lower in western coals, and intermediate in the Interior coal province. The concentrations of many trace elements are positively correlated with each other in their occurrence.
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From page 23... ...
The uranium content of the north-central Midcontinent bituminous coal is generally 10 to 15 ppm1 the sparsely distributed "uranium lignite" of South Dakota rarely contains more than 100 ppm. To release and recover the uranium from the ash of the combusted coal in both areas would require the pulverization of the ash, followed by treatment with strong acid and alkali chemicals, a process that is far too expensive (equipment- and labor-intensive)
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From page 24... ...
Chemical Procedures over the years a host of techniques has evolved for determininq trace elements in coal, coke, and coal ash. More recently, the trend has been to develop instrumental techniques, in preference to chemical, colorimetric, or "wet" techniques, because these procedures tend to be faster, less tedious, and qenerally yield acceptable results when sufficiently checked.
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From page 25... ...
currently, of those listed in Table 10, the most-used methods for analyzing trace elements in coal are activation analysis, optical emission, atomic absorption, x-ray fluorescence, and mass spectrometry or combinations of these methods. In general, each of these methods is quantitatively applicable to many elements, not just for those elements listed.
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From page 26... ...
TABLE 10 Literature Available for the Determination of Trace Elements in Coal and Coal Asha Multi elemental Sb As Be B Cd Cr Cu Fe Pb Mn Hg Ni Se v Zn Th u Activation 1-12 20 37 - - - - - 67 - - 75, 76 - 87 - - 95, 96, 107 95, 96, analysis 98, 99, 107 Optical 13-19 - 38, 39 50 55-58 62 - - - - 73 - - 88 90 62 emission Atomic 20-22 - 40 51 - 63 64 - - 71 - 77-83 - - - 63 absorp tion X-ray fluo- 23-27 - - - - - - - - - - - - 89 - - 97 97 "" 0\ rescence Mass spec- 28-30 - - 52 trometry Chemically 31 - 41-49 53, 54 59-61 - 65 66 68-70 72 74 84-86 66 - 65, 91 92-94 - 100-106 based (includes colorimetric and polaro graphic Mixed 20, 32-36 approaches -- aNumbers are keyed to accompanying references.
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From page 27... ...
1975. Trace elements by instrumental neutron activation analysis for pollution monitoring.
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1969. Determination of sodium, potassium, calcium, and magnesium in siliceous coal ash and related materials by atomic-absorption spectrophotometry.
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1973. Use of inorganic ion exchangers in the neutron activation determination of arsenic in coal ash.
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1961. Spectrochemical determination of germanium, beryllium, and scandium in coal ash.
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From page 31... ...
1975. Determination of lead in coal and coal ashes by flameless atomic absorption spectrometry.
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From page 32... ...
1969. Neutron activation analysis of the selenium content of fossil fuels.
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From page 33... ...
1974. Rapid, instrumental neutron activation analysis for the determination of uranium in environmental matrices.
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From page 34... ...
This can be a limiting factor on what type of sample and analytical procedure may be applied. For example, instrumental neutron activation analysis can be applied to any matrix and requires no sample pretreatment.
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From page 35... ...
There is a need for more standards representing ranks of coals in addition to bituminous and subbituminous coals. Because some trace elements are in different chemical associations in subbituminous or lignite coalsi as compared with their association in bituminous coals, the chemical analysis problems might differ significantly.
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From page 36... ...
Further research is needed on the elucidation of specific association of the mineral state of inorganically combined elements and also on the nature of the organically combined elements in coal and related materials. These questions have been addressed by several investigators (Given, 1974; Gluskoter et al., 1976; Koppenaal and Manahan, 1976; Zobovic, 1976)
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From page 37... ...
Pathways of exposure may be as direct as coal dust inhaled by underground coal miners or as circuitous as ingestion via bioaccumulation through the food chain. Fossil-fuel-cycle activities may mobilize metals over short distances, as in windblown coal fines lost during transportation, or over thousands of miles, as in increased concentrations of fossil-fuel-derived elements in the Greenland ice sheet, oceanic sediments, and midoceanic trade winds and at the South Pole (Dickson, 1972; Duce et al., 1975; Weiss et al., 1971; Zoller et al., 1974)
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From page 38... ...
. Except for dust and metal assays of the lungs of deceased underground coal miners, evaluation of actual metal dose resulting from a particular process of the coal-fuel cycle is not directly ascertainable for an individual.
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