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Articles 31 - 60 of 94

Full-Text Articles in Bioresource and Agricultural Engineering

Geopolymerization Of Coal Ash To Produce Cementless Binders, Hamid Akbari, Robert Mensah-Biney, Jonathan Simms Jan 2017

Geopolymerization Of Coal Ash To Produce Cementless Binders, Hamid Akbari, Robert Mensah-Biney, Jonathan Simms

Coal Combustion and Gasification Products Journal Archive

The main objective of this study was to evaluate geopolymer concrete made from coal combustion by-products, disposed of in landfills, as a potential substitute for the ordinary Portland cement (OPC), which is responsible for 5-8% of the total CO2 emissions in the world. In this study, a coal fly ash sample from the Carolinas was used in a chemical process known as geopolymerization to produce a “geopolymer” binder. The developed geopolymer binder could competently substitute the OPC binder in regular concrete applications. An experimental design program was conducted to optimize parameters of the geopolymerization affecting the strength of the final …


Groundwater Monitoring And Data Analysis Under The Coal Combustion Residuals Rule, Bruce Hensel Jan 2017

Groundwater Monitoring And Data Analysis Under The Coal Combustion Residuals Rule, Bruce Hensel

Coal Combustion and Gasification Products Journal Archive

No abstract provided.


Ponded And Landfilled Fly Ash As A Source Of Rare Earth Elements From A Kentucky Power Plant, James C. Hower, John G. Groppo, Kevin R. Henke, Uschi M. Graham, Madison M. Hood, Prakash Joshi, Dorin V. Preda Jan 2017

Ponded And Landfilled Fly Ash As A Source Of Rare Earth Elements From A Kentucky Power Plant, James C. Hower, John G. Groppo, Kevin R. Henke, Uschi M. Graham, Madison M. Hood, Prakash Joshi, Dorin V. Preda

Coal Combustion and Gasification Products Journal Archive

Twenty samples, with one composite sample built out of the 20 individual samples, of ponded ash were collected at a Kentucky power plant. The coal feed throughout the history of the power plant was central eastern Kentucky low- to moderate-S high volatile A bituminous coal. The pond was in the process of being excavated, with the ash moved to a landfill on another company property. In spite of the long history of the pond and the expected variation in coal supply, and perhaps because of the mixing due to the excavation, there is little variation in ash-basis rare earth elements …


Rare Earth Element Distribution In Fly Ash Derived From The Fire Clay Coal, Kentucky, Madison M. Hood, Ross K. Taggart, Ryan C. Smith, Heileen Hsu-Kim, Kevin R. Henke, Uschi Graham, John G. Groppo, Jason M. Unrine, James C. Hower Jan 2017

Rare Earth Element Distribution In Fly Ash Derived From The Fire Clay Coal, Kentucky, Madison M. Hood, Ross K. Taggart, Ryan C. Smith, Heileen Hsu-Kim, Kevin R. Henke, Uschi Graham, John G. Groppo, Jason M. Unrine, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Fly ash was collected from individual mechanical and electrostatic precipitator (ESP) hoppers at a 130-MW pulverized-coal utility unit burning a southeastern Kentucky moderate- to high-S Pennsylvanian Fire Clay coal. The fly ash particle size is generally similar within each row of the mechanical and ESP hoppers, with the mean particle diameter decreasing from >36 μmin the mechanical hoppers to 6 μm in the last ESP row. Rare earth element (REE)–bearing phases occur within fine minerals and, possibly, as part of the fly ash glass phase. Transmission electron microscopy was used to identify Y-Ce-Nd-La–bearing regions within a glassy matrix. Y- and …


The Relative Impact Framework For Evaluating Coal Combustion Residual Surface Impoundment Closure Options: Applications And Lessons Learned, Ari S. Lewis, Andrew B. Bittner Jan 2017

The Relative Impact Framework For Evaluating Coal Combustion Residual Surface Impoundment Closure Options: Applications And Lessons Learned, Ari S. Lewis, Andrew B. Bittner

Coal Combustion and Gasification Products Journal Archive

In response to the U.S. Environmental Protection Agency’s new rule regarding the disposal of coal combustion residuals (CCRs), many utilities need to re-examine their waste disposal practices and make decisions regarding if and how unlined surface impoundments (SIs) should be closed. The two primary options for closing SIs are in-place closure, with capping and engineering controls, and excavation of the CCR for transport to and re-disposal in a lined landfill. To help inform closure option decisions, we supported the Electric Power Research Institute’s development of a practical, science-based decision framework that comprehensively evaluates the potential impacts to human health and …


Characteristics And Composition Of Magnetic Concentrates Of Bottom Ash Samples From Two Types Of Thermal Power Plants In Odisha, India, Subir Kumar Das Jan 2016

Characteristics And Composition Of Magnetic Concentrates Of Bottom Ash Samples From Two Types Of Thermal Power Plants In Odisha, India, Subir Kumar Das

Coal Combustion and Gasification Products Journal Archive

Aluminosilicate bottom ash samples were examined from a thermal power plant in Talcher (sample NT-BA) and in Sambalpur (sample HR-BA), Odisha, India, to determine magnetic particle morphology, internal structure, mineralogy, mineral chemistry, ash fusion temperature, chemical composition, and leaching characteristics. The Talcher plant has adopted pulverized coal combustion, whereas the Sambalpur plant uses circulating fluidized bed combustion boiler technology. For NT-BA, most magnetic particles were ideal solid spheres (ferrospheres) with diverse morphological features (smooth, granular, dendritic and skeletal, porous, spotted, polygonal, and hollow [magnetite cenospheres]). For HR-BA, magnetic particles were subspherical, oval, and angular and showed widely varying surface morphologies, …


Distribution Of Uranium And Other Radionuclides In Coal And Coal Combustion Products, With Discussion Of Occurrences Of Combustion Products In Kentucky Power Plants, James C. Hower, Shifeng Dai, Greta Eskenazy Jan 2016

Distribution Of Uranium And Other Radionuclides In Coal And Coal Combustion Products, With Discussion Of Occurrences Of Combustion Products In Kentucky Power Plants, James C. Hower, Shifeng Dai, Greta Eskenazy

Coal Combustion and Gasification Products Journal Archive

Uranium and thorium are part of the mineral assemblages within coals. Uranium can also occur in organic associations, particularly in low-rank coals. While the average U concentration in coals is 2.9 ppm for low-rank coals and 1.9 ppm for bituminous and higher rank coals, high concentrations are known from certain low-rank and thin coals and from coals in areas associated with U mineralization. No high-U coals are mined for power production in the United States. Uranium and Th in coal combustion products are found in amounts more or less in proportion to their concentrations in the feed coal. Not being …


Carbon Dioxide Adsorption Studies On Fly Ash Zeolites, Denitza Zgureva Jan 2016

Carbon Dioxide Adsorption Studies On Fly Ash Zeolites, Denitza Zgureva

Coal Combustion and Gasification Products Journal Archive

In this study, the potential of fly ash zeolites (FAZ) Linde (LTA) and faujasite (FAU) to adsorb carbon dioxide (CO2) was investigated in view of the results of implementation in postcombustion carbon-capture technologies. Adsorption isotherms of selected samples were measured at 273.15 K by a Micromeritics Tristar II 3020 surface analyzer. The highest adsorption capacity was obtained for FAZ with a FAU structure synthesized by a two-stage fusion hydrothermal process from fly ash (FA) that was composed of 65 wt% amorphous components. The adsorption capacity for this sample reached a value of 136.40 mg CO2/g FAZ at atmospheric pressure, a …


Analysis Of Scientific Investigations Related To Reclamation Of Surface Mining Control And Reclamation Act Permitted Coal Mines With Coal Combustion By-Products, Kimery C. Vories Jan 2016

Analysis Of Scientific Investigations Related To Reclamation Of Surface Mining Control And Reclamation Act Permitted Coal Mines With Coal Combustion By-Products, Kimery C. Vories

Coal Combustion and Gasification Products Journal Archive

In the United states, the placement of coal combustion by-products (CCBs) (i.e., fly ash, bottom ash, boiler slag, flue gas desulfurization material, and fluidized bed combustion material) in coal mines has been an area of controversy. Federal and state governments, universities, the National Energy Technology Laboratory, and industrial research organizations have taken an active role in encouraging and promoting technological advances, research, and technology transfer related to the use of CCBs at coal mines. CCBs have been placed at Surface Mining Control and Reclamation Act of 1977 (SMCRA) permitted mines since 1977 to serve the following purposes: (1) a seal …


Coal Ash By-Product From Shanxi Province, China, For The Production Of Portland–Calcium Sulfoaluminate, Tristana Y. Duvallet, Thomas L. Robl, Kevin R. Henke, Yongmin Zhou, David Harris Jan 2016

Coal Ash By-Product From Shanxi Province, China, For The Production Of Portland–Calcium Sulfoaluminate, Tristana Y. Duvallet, Thomas L. Robl, Kevin R. Henke, Yongmin Zhou, David Harris

Coal Combustion and Gasification Products Journal Archive

Twenty bulk samples were collected from ponded coal combustion ash in Shanxi Province, China, as part of an investigation of their beneficiation potential. The samples were shipped to the University of Kentucky, where they were chemically analyzed. The samples were highly consistent in chemistry, falling within the ASTM C-618 class F compositional range. The particle size of the ponded ash was relatively coarse, with only ,7% by weight on average, falling below 200 mesh (75 mm) particle size. The bulk of the material (.80%) was within 50 by 200 mesh (equivalent to 300 by 75 mm). X-ray diffraction investigation combined …


Effect Of Coal Fly Ash Leachate On The Bioluminescence Intensity Of Vibrio Fischeri, Shiro Ikeda, Irena Kostova, Hideaki Sekine, Yoshika Sekine Jan 2016

Effect Of Coal Fly Ash Leachate On The Bioluminescence Intensity Of Vibrio Fischeri, Shiro Ikeda, Irena Kostova, Hideaki Sekine, Yoshika Sekine

Coal Combustion and Gasification Products Journal Archive

Coal fly ash is a residue of coal-fired thermoelectric power plants (TPPs) and is mostly dumped in ash ponds or landfill sites, even though it potentially contains significant amounts of water-soluble hazardous contaminants. Bioassay using the bioluminescent bacterium *Vibrio fischeri* is known to be applicable for assessing the short-term and sublethal toxicity of complex mixtures without the need for precise chemical characterization. However, this type of bioassay is potentially adversely influenced by the pH-induced protein denaturation of cells. Because coal fly ash leachates often have alkaline or acidic properties, when applying the *V. fischeri*-based bioassay to the samples, we need …


Influence Of Coal-Fired Power Plant Emissions Regulations And Consequent Engineering Controls And Coal-Supply Modifications On Fly Ash Chemistry And Petrology: Examples From Kentucky Power Plants, Madison M. Hood, John G. Groppo, Michelle N. Johnston, James C. Hower, Herek L. Clack, Diego S. De Medeiros, Silvio R. Taffarel, Cesar M.N.L. Cutruneo, Luis F.O. Silva Jan 2016

Influence Of Coal-Fired Power Plant Emissions Regulations And Consequent Engineering Controls And Coal-Supply Modifications On Fly Ash Chemistry And Petrology: Examples From Kentucky Power Plants, Madison M. Hood, John G. Groppo, Michelle N. Johnston, James C. Hower, Herek L. Clack, Diego S. De Medeiros, Silvio R. Taffarel, Cesar M.N.L. Cutruneo, Luis F.O. Silva

Coal Combustion and Gasification Products Journal Archive

The chemistry and petrology of fly ash are controlled by a number of factors: (1) chemistry of the feed coal (and added fuels, such as petroleum coke, tires, biomass, etc.), (2) particle size of the fuel feed (controlled by pulverized fuel vs. cyclone combustion, maintenance of pulverizers, etc.), (3) design of the boiler and pollution-control system, and (4) temperature of the flue gas at the collection point. In general, for any electrostatic precipitator or baghouse system, the concentrations of volatile trace elements in fly ash will increase with a drop in the flue gas temperature and a decrease in the …


Multistage Concentration Of Cenospheres In Fly Ash Using The Inverted Reflux Classifier, A. Kiani, J. Zhou, K.P. Galvin Jan 2015

Multistage Concentration Of Cenospheres In Fly Ash Using The Inverted Reflux Classifier, A. Kiani, J. Zhou, K.P. Galvin

Coal Combustion and Gasification Products Journal Archive

Cenospheres are one of the most valuable components found in the fly ash waste of coal-fired power stations, consisting of hollow, aluminosilicate spherical shells and offering very low bulk density, high strength, and high thermal resistance. Although wet processing methods offer the best prospect for achieving recovery and concentration of the cenospheres, significant impediments remain for achieving satisfactory economics. This work was concerned with the recovery and concentration of cenospheres from fly ash using a novel system, the inverted reflux classifier (IRC), covering single and multistage processing. The system consists of a series of parallel inclined channels mounted underneath an …


Strengthening Black Cotton Soil With Fly Ash And Moorum: An Investigation Of The Role Of Subgrade And Subbase Layers, Gourav Saxena, Nikhlesh Chaurasia Jan 2015

Strengthening Black Cotton Soil With Fly Ash And Moorum: An Investigation Of The Role Of Subgrade And Subbase Layers, Gourav Saxena, Nikhlesh Chaurasia

Coal Combustion and Gasification Products Journal Archive

One of the most effective and economical methods to strengthen clayey soils is addition of stabilizing agents such as fly ash to the soil. In this study, highly plastic clay was stabilized using fly ash. Geotechnical properties such as Atterberg limits, unconfined compressive strength (UCS), and the California bearing ratio (CBR) value of virgin black cotton soil and soil treated with fly ash were evaluated. Soil was stabilized with various proportions of fly ash, i.e., at 0%, 10%, 15%, 20%, and 30%. The UCS of black cotton soil–fly ash mixes is found to be at its maximum at 20% fly …


Using Coal Fly Ash In Agriculture: Combination Of Fly Ash And Poultry Litter As Soil Amendments For Bioenergy Feedstock Production, E. Kudjo Dzantor, Ekundayo Adeleke, Vanaha Kankarla, Oluwatosin Ogunmayowa, Dafeng Hui Jan 2015

Using Coal Fly Ash In Agriculture: Combination Of Fly Ash And Poultry Litter As Soil Amendments For Bioenergy Feedstock Production, E. Kudjo Dzantor, Ekundayo Adeleke, Vanaha Kankarla, Oluwatosin Ogunmayowa, Dafeng Hui

Coal Combustion and Gasification Products Journal Archive

Increasing fiscal, human, and environmental costs of coal fly ash (FA) management are leading to advocacy for greater beneficial uses of the by-products as soil amendments in agriculture. Greenhouse experiments were conducted in Armour silt loam (ASL) soil that was amended with FA (10%, wt/wt) with and without poultry litter (PL 5 75 mg N/kg). Biomass productivity of eastern gamagrass (GG), a warm-season perennial grass, was measured to serve as complementary biofuel feedstock to switchgrass (SG). FA was obtained from a site at the 2008 ash spill in Kingston, TN. GG and SG were grown individually in 15-cm-wide 3 41-cm-high …


Fabrication And Testing Of Low-Energy Calcium Sulfoaluminate-Belite Cements That Utilize Circulating Fluidized Bed Combustion By-Products, Robert Jewell, Robert Rathbone, Tristana Duvallet, Thomas Robl, Kamyar Mahboub Jan 2015

Fabrication And Testing Of Low-Energy Calcium Sulfoaluminate-Belite Cements That Utilize Circulating Fluidized Bed Combustion By-Products, Robert Jewell, Robert Rathbone, Tristana Duvallet, Thomas Robl, Kamyar Mahboub

Coal Combustion and Gasification Products Journal Archive

The utilization of circulating fluidized bed combustion (CFBC) ash to make cement products that provide added value and offset CO2 production is the objective of this research. CFBC burns coal in the presence of a bed of slaked limestone, which effectively absorbs sulfur dioxide (SO2) to form anhydrite (CaSO4). CFBC produces two kinds of spent bed materials, coarse bottom ash and a much finer fly ash. Both of these products are very high in calcium. When properly conditioned, these materials are capable of acting as hydraulic cements, forming both calcium aluminosulfate minerals, most importantly ettringite, as well as calcium-alumina-silica gels, …


Prediction Of The Unburned Carbon Content Of Fly Ash In Coal-Fired Power Plants, Saeid R. Dindarloo, James C. Hower Jan 2015

Prediction Of The Unburned Carbon Content Of Fly Ash In Coal-Fired Power Plants, Saeid R. Dindarloo, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Prediction of carbon content in fly ash is a valuable index in both designing and optimizing coal-fired boilers. In this study, methods of multiple regression (MR), decision trees (DT), and support vector regression (SVR) were used for prediction of unburned carbon content of fly ash in a 300-MW power plant with a tangentially fired furnace using a low-NOx concentric firing system. Twenty-one boiler operational and coal petrological variables from 21 experiments in a previous benchmark study were used. A variables correlation matrix was used for feature (independent variables) selection in order to reduce the dimensions (number) of input variables from …


Recycling Of Lignite Coal Fly Ash By Its Conversion Into Zeolites, Silviya Boycheva, Denitza Zgureva, Annie Shoumkova Jan 2015

Recycling Of Lignite Coal Fly Ash By Its Conversion Into Zeolites, Silviya Boycheva, Denitza Zgureva, Annie Shoumkova

Coal Combustion and Gasification Products Journal Archive

The present study emphasized the conversion of fly ash from lignite coals into zeolites by a double-stage fusion-hydrothermal synthesis. The raw and the converted fly ashes were characterized with respect to their morphology, composition, and crystallinity. The effects of process parameters such as fusion temperature, concentration of the alkaline activator, and the duration of the hydrothermal incubation on the zeolitization process were studied. The experimental results indicate that the fusion temperature does not influence the process mechanism in the range 550–850uC, but it has an acceleration effect. The elevation of the sodium hydroxide/fly ash ratio from 1.6 to 2.0 enhances …


Synthesis And Characterization Of High-Iron Alite-Calcium Sulfoaluminate-Ferrite Cements Produced From Industrial By-Products, Tristana Y. Duvallet, Youngmin Zhou, Thomas L. Robl, Rodney Andrews Jan 2014

Synthesis And Characterization Of High-Iron Alite-Calcium Sulfoaluminate-Ferrite Cements Produced From Industrial By-Products, Tristana Y. Duvallet, Youngmin Zhou, Thomas L. Robl, Rodney Andrews

Coal Combustion and Gasification Products Journal Archive

Ordinary Portland cement (OPC) and calcium sulfoaluminate cement (CSAC) are well-known and commonly used construction materials. The clinker phases mainly responsible for their strength development are C3S (alite) in OPC, which hydrates to form a calcium silicate gel phase; and C4A3S ´ (calcium sulfoaluminate) in CSAC, which hydrates to rapidly form ettringite. The purpose of this work was to produce high-iron alite-calcium sulfoaluminate-ferrite cements, by combining C4AF (ferrite), from 5% to 50% by weight, to the C3S and C4A3S ´ clinker phases. Producing this alite-calcium sulfoaluminate-ferrite cement would decrease the requirement of bauxite in the raw materials, which would consequently …


Experimental And Modelling Evaluation Of Slagging Behaviour Of German Lignite, Martin Kaiser, Alexander Ilyushechkin Jan 2014

Experimental And Modelling Evaluation Of Slagging Behaviour Of German Lignite, Martin Kaiser, Alexander Ilyushechkin

Coal Combustion and Gasification Products Journal Archive

The behaviour of mineral matter is important for the characterisation of coal for use in entrained-flow gasification technologies. We investigated four behavioural characteristics—ash fusion temperatures (AFT), slag viscosity versus temperature profiles, temperatures of critical viscosity (TCV), and slag phase compositions—of Rhenish lignite coal ash using laboratory and modelling tools. Our modelling of AFT using coal ash composition provided a wide range of data, with only one (modified) model demonstrating agreement with experimental data. Experimental slag viscosity data were obtained over a temperature range from 1200uC to 1500uC. Where relevant, TCV was also measured. Comparison of these data to the calculated …


Fly Ash As A Potential Scrubber Of Acidic Wastes From The Phosphate Industries In Israel, Roy Nir Lieberman, Eli Lederman, Ithamar Pelly, Haim Cohen Jan 2014

Fly Ash As A Potential Scrubber Of Acidic Wastes From The Phosphate Industries In Israel, Roy Nir Lieberman, Eli Lederman, Ithamar Pelly, Haim Cohen

Coal Combustion and Gasification Products Journal Archive

Fly ash (FA) is produced in Israeli utilities via bituminous coal combustion. It is used as a cement additive or in concrete production, and its economic value is low. The FA produced in Israel is very basic (defined as class F) owing to ambient air quality standards that impose low sulfur content in the imported coals. Because the lime content is high (in the South African coal, ,10 wt%), it is a good potential chemical scrubber to acidic wastes. The phosphate industry in Israel produces mainly phosphate fertilizers and water-treatment products as well as phosphoric acid. The production methods rely …


Geochemistry And Mineralogy Of Coal-Fired Circulating Fluidized Bed Combustion Fly Ashes, Luis F.O. Silva, Marcos L.S. Oliveira, Rubens M. Kautzmann, Claudete G. Ramos, Maria Izquierdo, Shifeng Dai, Jennifer Wilcox, Jeremy Hoffman, James C. Hower Jan 2014

Geochemistry And Mineralogy Of Coal-Fired Circulating Fluidized Bed Combustion Fly Ashes, Luis F.O. Silva, Marcos L.S. Oliveira, Rubens M. Kautzmann, Claudete G. Ramos, Maria Izquierdo, Shifeng Dai, Jennifer Wilcox, Jeremy Hoffman, James C. Hower

Coal Combustion and Gasification Products Journal Archive

The fuel, bed ash, and fly ash were sampled from a circulating fluidized bed combustion (CFBC) unit at two times. The first sampling was a high-sulfur (S) coal-only run, and the second sampling coincided with an experimental burn of up to 10% switchgrass (Panicum virgatum) pressed pellets mixed with a high-S coal. The latter blend had a higher moisture content and a lower heating value than the coal-only fuel. Given the time between the samplings and the special needs for the experimental run, unavoidable changes in the coal and limestone complicate comparisons of the bed ash and fly ash chemistry …


Trends In Coal Utilization And Coal Combustion Product Production In Kentucky: Results Of The 2012 Survey Of Power Plants, James C. Hower, Gerald A. Thomas, Shelley G. Hopps Jan 2014

Trends In Coal Utilization And Coal Combustion Product Production In Kentucky: Results Of The 2012 Survey Of Power Plants, James C. Hower, Gerald A. Thomas, Shelley G. Hopps

Coal Combustion and Gasification Products Journal Archive

The University of Kentucky Center for Applied Energy Research has conducted a survey of Kentucky’s utility coal-fired power plants every 5 years since 1992. The survey includes a collection of the feed coal and the coal combustion products (CCPs). The latest collection was in 2012, with the accompanying information survey covering trends in 2011. Overall coal-fired energy production decreased, and the nature of the CCPs changed for a number of reasons, including but not limited to, increased gas production in the Appalachians, a series of warm winters, energy conservation, depletion of Appalachian coal reserves, and utility responses to regulations. From …


The John Zink Hamworthy Combustion Handbook, 2nd Edition, Volume 1: Fundamentals, Edited By Charles E. Baukal, Jr., Crc Press, Boca Raton, Fl, 2013., Payal A. Chandan Jan 2013

The John Zink Hamworthy Combustion Handbook, 2nd Edition, Volume 1: Fundamentals, Edited By Charles E. Baukal, Jr., Crc Press, Boca Raton, Fl, 2013., Payal A. Chandan

Coal Combustion and Gasification Products Journal Archive

No abstract provided.


Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston Jan 2013

Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston

Coal Combustion and Gasification Products Journal Archive

Given the worldwide demand for rare earth elements (REEs) in modern electronics, all potential sources of the REEs should be investigated. Coal-combustion fly ash represents a potential source of REEs. Fly ashes, derived from the combustion of coals from Kentucky in the United States and Jungar in China, were examined by wavelength-dispersive spectrometry electron microprobe analysis of epoxy-bound polished pellets. From previous studies, it was known that the REEs did not show any enrichment relative to flue gas temperature at the point of collection or to the particle size, that is, external surface area, of the particles. Cerium, the most …


Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik Jan 2013

Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik

Coal Combustion and Gasification Products Journal Archive

Weinvestigated the mobility of inorganic elements in the ash dump due to chemical interaction of weathered dry disposed ash conditioned with high-saline effluents and ingressed CO2 from atmosphere and percolating rainwater. Drilled ash core samples collected from dry disposed ash dump at a South African coal-burning power station were characterized using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses. A modified sequential extraction procedure was selected to determine the mineralogical association of the investigated elements in the 1-year-old drilled ash cores. Major mineral phases are quartz and mullite and other minor phases included hematite, lime, calcite, anorthite, mica, and enstatite. …


Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling Jan 2013

Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling

Coal Combustion and Gasification Products Journal Archive

Ammonium nitrate (AN) is an essential plant nutrient for plant growth. Ammonium nitrate is also an ingredient in explosives. Research is being conducted on reducing the explosiveness of AN by encapsulating it with the use of coal by-products. The objective of this greenhouse pot study was to determine the effects of class C and F fly ash and flue gas desulfurization-gypsum-encapsulated AN on biomass, grain, and straw yield and nitrogen and metals uptake by wheat. Encapsulated AN was mixed with a low-nitrogen soil at 56 and 112 kg N ha^-1^, as well as unencapsulated AN as a control, and planted …


Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra Jan 2013

Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra

Coal Combustion and Gasification Products Journal Archive

Fly ash is a major by-product of thermal power plants that adversely affects land, water, and air. Its gainful utilization in many areas is being continuously explored. Use of fly ash in opencast coal mine haul road construction is one such option. This article reports detailed laboratory investigations carried out on clinker-stabilized fly ash–mine overburden mixes to evaluate their suitability for subbase of mine haul roads. Composite materials were prepared from fly ash, mine overburden, and clinker at different proportions. Proctor compaction test, unconfined compressive strength (UCS), and ultrasonic pulse velocity tests were carried out at different curing periods. UCS …


A Note On The Occurrence Of Yttrium And Rare Earth Elements In Coal Combustion Products, James C. Hower, Shifeng Dai, Vladimir V. Seredin, Lei Zhao, Irena J. Kostova, Luis F.O. Silva, Sarah M. Mardon, Gulbin Gurdal Jan 2013

A Note On The Occurrence Of Yttrium And Rare Earth Elements In Coal Combustion Products, James C. Hower, Shifeng Dai, Vladimir V. Seredin, Lei Zhao, Irena J. Kostova, Luis F.O. Silva, Sarah M. Mardon, Gulbin Gurdal

Coal Combustion and Gasification Products Journal Archive

There is an international need for a variety of lanthanide elements (rare earth elements, or REEs) in modern electronic and related components. This has led to a desire to broaden production from both previously productive locations and to expand production to new sources, possibly including coal-derived fly ash. The concentration of lanthanides in coal-combustion fly ash depends on a number of factors, one of the most important being the concentration of the elements in the feed coal. Unlike some elements, such as Zn and As, the REE concentration is largely not a function of element volatility. In this study, we …


Fouling Intensity Of Three Indian Coals, S. Balakrishnan, R. Nagarajan Jan 2013

Fouling Intensity Of Three Indian Coals, S. Balakrishnan, R. Nagarajan

Coal Combustion and Gasification Products Journal Archive

Ash particles can arrive at heat-transfer surfaces either in solid (solidified) state or in molten state, depending on the factors such as location inside the boiler, temperature, and residence time. In this study, arrival of ash particles in solid state, which can occur in the convective section of the boiler, was considered. Apart from the inertial force that drives particles .10 mmto the surface, the low-melting inorganic alkali vapors play a vital role in deposit formation by promoting sticking. Chemical equilibrium calculations were performed to calculate the equilibrium composition of flue gas, as well as the amount of condensable inorganic …