Coal Utilization

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Tonya M Brubaker - One of the best experts on this subject based on the ideXlab platform.

  • strontium isotope study of Coal Utilization by products interacting with environmental waters
    Journal of Environmental Quality, 2012
    Co-Authors: Lev J Spivakbirndorf, Elizabeth C. Chapman, Karl T Schroeder, Rosemary C Capo, Brian W Stewart, Tonya M Brubaker
    Abstract:

    Sequential leaching experiments on Coal Utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of Coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements—including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc—during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ({sup 87}Sr/{sup 86}Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed Coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-{sup 87}Sr/{sup 86}Sr) component. A changing Sr isotope ratio of CUB-interacting waters inmore » a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB–water interaction.« less

  • STRONTIUM ISOTOPE SYSTEMATICS OF Coal Utilization BYPRODUCTS AND THEIR INTERACTION WITH ENVIRONMENTAL WATERS
    2011
    Co-Authors: Tonya M Brubaker
    Abstract:

    The major element and strontium isotope systematics and geochemistry of Coal Utilization byproducts (CUB) and their interactions with environmental waters were investigated using laboratory leaching experiments with water, sodium carbonate, acetic acid, nitric acid, and hydrochloric acid. Analysis of elemental data from both column and sequential leaching procedures shows rapid release of most major elements early in the leaching procedure, excluding silicon and iron, suggesting association with soluble and surface bound phases. Possible sulfate mineral phases can be inferred due to the high proportions of S leached with sodium carbonate solution, effective at dissolving sulfates such as anhydrite (CaSO3). For all elements except sulfur, highly acidic leachates were most effective in extracting elements from the CUB. In both the column and sequential leaching procedures silicon was leached most effectively by stronger acidic solutions later in the experiment, suggesting the presence of a more resistant silicate phase, possibly residual biotite, feldspar, or clays, or an amorphous glass phase formed during combustion.Isotopic results from the column leaching experiment show a marked increase in 87Sr/86Sr ratio with continued leaching. This general trend is also seen in the sequential leaching data, showing an increase in 87Sr/86Sr ratio with continued leaching in increasingly acidic solutions. These data show that there are isotopically distinct phases within the CUB, suggesting the presence of a more resistant, highly radiogenic phase that survives the combustion process and is leached after the more soluble minerals are removed. The Sr isotope systematics and leaching behavior of the Class F CUB samples demonstrate that isotopic homogenization of minerals in Coal does not always occur during the combustion process, despite the high temperatures encountered in the boiler. A key factor in accessing more resistant phases within CUB appears to be the extent of leaching, rather than the particular leaching procedure or acid used. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic composition of CUB could be distinguishable from other sources and a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and groundwaters.

Brian W Stewart - One of the best experts on this subject based on the ideXlab platform.

  • strontium isotope study of Coal Utilization by products interacting with environmental waters
    Journal of Environmental Quality, 2012
    Co-Authors: Lev J Spivakbirndorf, Elizabeth C. Chapman, Karl T Schroeder, Rosemary C Capo, Brian W Stewart, Tonya M Brubaker
    Abstract:

    Sequential leaching experiments on Coal Utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of Coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements—including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc—during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ({sup 87}Sr/{sup 86}Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed Coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-{sup 87}Sr/{sup 86}Sr) component. A changing Sr isotope ratio of CUB-interacting waters inmore » a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB–water interaction.« less

  • Tracing the interaction of acid mine drainage with Coal Utilization byproducts in a grouted mine: Strontium isotope study of the inactive Omega Coal Mine, West Virginia (USA)
    Applied Geochemistry, 2010
    Co-Authors: Barbara L. Hamel, Brian W Stewart, Ann G. Kim
    Abstract:

    Abstract In order to ameliorate acidic discharge, the inactive Omega Coal Mine, West Virginia was partially filled by injection of a grout consisting of 98% Coal Utilization byproducts (CUB), including fluidized bed combustion ash and fly ash, and 2% Portland cement. In this study, discharge chemistry and Sr isotope ratios were determined to identify and quantify the extent of interaction between mine waters and the CUB–cement grout. Eight sampling sites were monitored around the downdip perimeter of the mine. The major and trace element chemistry of the discharges was generally not sufficient to distinguish between discharges that interacted with grout and those that did not. Elements that showed the most separation include K and As, which were elevated in some waters that interacted with CUB–cement grout. In contrast, the Sr isotope ratios clearly distinguished discharges from grouted and non-grouted areas. Discharges that bypassed the grouted portions had 87 Sr/ 86 Sr ratios ranging from 0.71510 to 0.71594, while two discharges that interacted with grout had ratios in the range of 0.71401–0.71456. The Treatment Inlet, which includes both grouted and ungrouted discharges, yielded intermediate isotopic ratios. Leaching experiments on CUB–cement grout, Coal and surrounding rocks are consistent with the isotopic trends observed in the discharges. Based on these results, waters that interacted with grout received 30–40% of their Sr from the CUB–cement grout material. These results suggest that the grout material is chemically eroding at a rate of approximately 0.04% per year. This novel application of the Sr isotope system illustrates its ability to sensitively track and quantify fluid interaction with Coal and CUB-based grout.

Lev J Spivakbirndorf - One of the best experts on this subject based on the ideXlab platform.

  • strontium isotope study of Coal Utilization by products interacting with environmental waters
    Journal of Environmental Quality, 2012
    Co-Authors: Lev J Spivakbirndorf, Elizabeth C. Chapman, Karl T Schroeder, Rosemary C Capo, Brian W Stewart, Tonya M Brubaker
    Abstract:

    Sequential leaching experiments on Coal Utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of Coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements—including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc—during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ({sup 87}Sr/{sup 86}Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed Coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-{sup 87}Sr/{sup 86}Sr) component. A changing Sr isotope ratio of CUB-interacting waters inmore » a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB–water interaction.« less

Karl T Schroeder - One of the best experts on this subject based on the ideXlab platform.

  • strontium isotope study of Coal Utilization by products interacting with environmental waters
    Journal of Environmental Quality, 2012
    Co-Authors: Lev J Spivakbirndorf, Elizabeth C. Chapman, Karl T Schroeder, Rosemary C Capo, Brian W Stewart, Tonya M Brubaker
    Abstract:

    Sequential leaching experiments on Coal Utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of Coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements—including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc—during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ({sup 87}Sr/{sup 86}Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed Coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-{sup 87}Sr/{sup 86}Sr) component. A changing Sr isotope ratio of CUB-interacting waters inmore » a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB–water interaction.« less

  • Environmental chamber measurements of mercury flux from Coal Utilization by-products
    Fuel, 2009
    Co-Authors: Natalie J. Pekney, Karl T Schroeder, Donald V. Martello, Evan J. Granite
    Abstract:

    Abstract An environmental chamber was constructed to measure the mercury flux from Coal Utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7-day experiment averages ranging from −6.8 to 73 ng/m2 h for the fly ash samples and −5.2 to 335 ng/m2 h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.

  • Measurement of mercury flux from Coal Utilization by- products with a laboratory flux chamber
    2007
    Co-Authors: Natalie J. Pekney, Karl T Schroeder, Donald V. Martello, Evan J. Granite
    Abstract:

    As a result of recent regulations, the emission of mercury in the flue gas of Coal-fired power plants will be reduced. This will result in the transfer of mercury to one or more of the Coal Utilization by-products depending on the mercury control strategy selected by the power plant. Over 40 percent of these Coal Utilization by-products (CUB), which include fly ash, bottom ash, boiler slag, and flue gas desulphurization (FGD) byproducts, are used beneficially to make wallboard, cement, and other products. The remainder is disposed in landfills and other impoundments. The potential release of mercury from CUB is being evaluated to help ensure the environmental acceptability of current disposal practices as well as the continued and expanded commercial use of these materials. While previous studies have shown that mercury in CUB is retained under most conditions, additional research into the potential for atmospheric releases is needed. Most studies have shown that CUB do not emit significant amounts of mercury to the atmosphere. However, the effects of temperature, moisture content, light exposure, and the increased mercury content resulting from mercury controls are not well studied. In response, the Department of Energy/National Energy Technology Laboratory’s Office of Research and Development is utilizing an environmental chamber to assess the influence of these factors on mercury flux from a variety of CUB materials.

Ann G. Kim - One of the best experts on this subject based on the ideXlab platform.

  • Tracing the interaction of acid mine drainage with Coal Utilization byproducts in a grouted mine: Strontium isotope study of the inactive Omega Coal Mine, West Virginia (USA)
    Applied Geochemistry, 2010
    Co-Authors: Barbara L. Hamel, Brian W Stewart, Ann G. Kim
    Abstract:

    Abstract In order to ameliorate acidic discharge, the inactive Omega Coal Mine, West Virginia was partially filled by injection of a grout consisting of 98% Coal Utilization byproducts (CUB), including fluidized bed combustion ash and fly ash, and 2% Portland cement. In this study, discharge chemistry and Sr isotope ratios were determined to identify and quantify the extent of interaction between mine waters and the CUB–cement grout. Eight sampling sites were monitored around the downdip perimeter of the mine. The major and trace element chemistry of the discharges was generally not sufficient to distinguish between discharges that interacted with grout and those that did not. Elements that showed the most separation include K and As, which were elevated in some waters that interacted with CUB–cement grout. In contrast, the Sr isotope ratios clearly distinguished discharges from grouted and non-grouted areas. Discharges that bypassed the grouted portions had 87 Sr/ 86 Sr ratios ranging from 0.71510 to 0.71594, while two discharges that interacted with grout had ratios in the range of 0.71401–0.71456. The Treatment Inlet, which includes both grouted and ungrouted discharges, yielded intermediate isotopic ratios. Leaching experiments on CUB–cement grout, Coal and surrounding rocks are consistent with the isotopic trends observed in the discharges. Based on these results, waters that interacted with grout received 30–40% of their Sr from the CUB–cement grout material. These results suggest that the grout material is chemically eroding at a rate of approximately 0.04% per year. This novel application of the Sr isotope system illustrates its ability to sensitively track and quantify fluid interaction with Coal and CUB-based grout.