Showing papers on "Fly ash published in 1980"
TL;DR: The physical and chemical properties of coal ashes are dependent on the coal's geological origin, combustion condition, efficiency of particulate removal, and degree of weathering before final disposal as discussed by the authors.
Abstract: Impacts of land-oriented utilization and disposal of various coal combustion residues are summarized. The physical and chemical properties of coal ashes are dependent on the coal's geological origin, combustion condition, efficiency of particulate removal, and degree of weathering before final disposal. Coal residues, applied on cropland, are not practical sources of essential plant nutrients N, P, and K; however, they can effectively serve as a supplementary supply of Ca, S, B, Mo, and Se to soils. Fly ash could also be an effective amendment in neutralizing soil acidity. Many of the observed chemical and biological effects of fly ash applications to soils resulted from the increased activities of Ca/sup 2 +/ and OH/sup -/ ions. Most unweathered fly ashes, especially those coming from the subbituminous and lignite coals of the western US, are high in these constituents and usually will cause high soil salinity. The accumulation of B, Mo, Se, and soluble salts in fly ash-amended soils appear to be the most serious constraints associated with land application of fly ash to soil.
753 citations
TL;DR: Fly ash specimens from four power plants in the Tennessee Valley Authority system have been separated into three matrices: glass, mullite-quartz, and magnetic spinel, revealing the magnetic component of fly ash is ferrite.
Abstract: Fly ash specimens from four power plants in the Tennessee Valley Authority system have been separated into three matrices: glass, mullite-quartz, and magnetic spinel. Chemical species of trace elements are defined to a large extent by the matrices that contain them. The magnetic component of fly ash is ferrite. The mullite-quartz phase is relatively pure and can be recovered as a resource.
221 citations
TL;DR: In this article, the authors investigate polychlorinated dibenzo-p-dioxins (PCDD) and related compounds in the fly ash and flue gasses of some municipal incinerators in the Netherlands.
189 citations
TL;DR: X-ray diffraction, Fourier transform infrared, and chemical-phase analyses were performed to determine elemental compositions of samples, and water-soluble sulfates are the predominant species present in oil-fired particulate emissions.
Abstract: A methodology for determining inorganic compounds present in particulate emissions from fossil fuel combustion processes is described Samples collected from power plants burning oil and coal fuels of different composition provided a typical range of flyashes for the investigation X-ray diffraction, Fourier transform infrared, and chemical-phase analyses were performed to determine elemental compositions of samples Water-soluble sulfates are the predominant species present in oil-fired particulate emissions (2 photos, 7 references, 9 tables)
175 citations
TL;DR: In this paper, the relative concentrations of elements in the aluminosilicate matrix and in nonmatrix or surface materials of coal flyash were determined, depending on particle size and the solubility of the elements in solutions of hydrochloric acid and hydrogen fluoride.
Abstract: Methods are developed to determine quantitative relative concentrations of elements in the aluminosilicate matrix and in nonmatrix or surface materials of coal flyash. The total element concentration is shown to be dependent on particle size and the solubility of elements in solutions of hydrochloric acid and hydrogen fluoride. Greater than 70% of the sodium, potassim, magnesium, iron, thorium, hafnium, and titanium is associated with the aluminosilicate matrix. More than 70% of the calcium, nickel, anthanum, scandium, strontium, and rare earth elements is associated with an acid-soluble phase. More than 70% of the zinc, cadmium, vanadium, selenium, tungsten, molybdenum, antimony, arsenic, and uranium is associated with surface material on the ash particles. The elements manganese, chormium, beryllium, copper, cobalt, barium, lead, and gallium are distributed about equally between matrix and nonmatrix material. (1 diagram, 6 graphs, 25 references, 3 tables)
122 citations
TL;DR: In this article, fly ash from a western U.S. coal source was added to a calcareous soil and an acid soil at rates ranging up to and including 8% by weight.
116 citations
100 citations
TL;DR: The 309 organic compounds reported in the literature as emissions from selected combustion processes are tabulated, with 109 originating from coal combustion, 213 from waste incineration and 69 from coal/refuse combustion as mentioned in this paper.
99 citations
TL;DR: In this article, coal and fly ash were analyzed for major ash elements by fusing with lithium tetraborate in an automatic fusion device, the Claisse Fluxer.
Abstract: The coal sample is first ashed with high temperature ashing or with RF plasma low temperature ashing. The coal ash or fly ash can be analyzed for major ash elements by fusing with lithium tetraborate in an automatic fusion device, the Claisse Fluxer. The ash samples are also dissolved in a Parr bomb in a mixture of aqua regia and HF. Subsequently, the solutions are analyzed for eight major (Al, Ca, Fe, K, Mg, Na, Si, and Ti) and 20 trace elements (As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sr, U, V, and Zn) by inductively coupled plasma emission spectroscopy. Mercury in coal and fly ash is determined on a separate aliquot by the cold vapor atomic absorption technique. Fluorine and chlorine in the samples are determined by fusing with Na/sub 2/CO/sub 3/ and Eschka mixture, respectively, and then measuring the two ions in solution with specific ion electrodes. Oxygen in the samples can be determined rapidly and nondestructively by 14-MeV neutron activation analysis. These methods have been tested by analyzing several NBS coal and fly ash standards with good accuracy and reproducibility. 10 tables.
98 citations
01 Sep 1980
TL;DR: In this article, the effect of partially replacing Portland cement with either ground granulated blast-furnace slag or fly ash on the performance of massive concrete pours was investigated.
Abstract: The Paper presents the results of an investigation to monitor the effect of partially replacing Portland cement with either ground granulated blast-furnace slag or fly ash on the performance of massive concrete pours. Temperature and strain were monitored in three pours each 4.5 m deep which form part of the foundations for a grinding mill at the Frodingham Cement Works in Scunthorpe. The total cementitious material content in each pour was 400 kg/m3. In one case 75% of the OPC was replaced by granulated slag and in another, 30% was replaced by fly ash. Strengths were measured under British Standard and temperature matched curing conditions to observe the effect of the in situ heat cycle. To enable a theoretical assessment of thermal stresses at early age to be made, laboratory tests on similar concrete were carried out to determine adiabatic temperature rise, thermal movement, elastic modulus and creep characteristics. Results of the laboratory and site investigations are assessed in relation to existing data.
TL;DR: A number of adsorbed polycyclic aromatic hydrocarbons will spontaneously oxidize in the absence of light, with those compounds containing a benzylic carbon being particularly susceptible.
Abstract: Polycyclic aromatic hydrocarbons adsorbed onto coal fly ash were found to be stabilized against photochemical decomposition. However, a number of adsorbed polycyclic aromatic hydrocarbons will spontaneously oxidize in the absence of light, with those compounds containing a benzylic carbon being particularly susceptible. The decomposition rate appears to be fly ash-dependent.
TL;DR: Aqueous chemistry of fly ash from a western coal-fired power plant was characterized through measurements of solubility of Ca, Mg, Na, K, OH, CO/sub 3, HCO/sub 4/OAc-HOAc, and B in filtrates from water and electrolyte suspensions of the fly ash obtained at various dilution ratios as discussed by the authors.
Abstract: Aqueous chemistry of fly ash from a western coal-fired power plant was characterized through measurements of solubility of Ca, Mg, Na, K, OH, CO/sub 3/, HCO/sub 3/, Cl, SO/sub 4/, and B in filtrates from water and electrolyte suspensions of the fly ash obtained at various dilution ratios. Acid titrations of dilute suspensions of the fly ash were also characterized. The study also examined the quantitative relationship between electrical conductivity of the filtrates and their total ionic composition. Relative concentrations of Ca and OH ions in solution and the nature of the acid titration curves suggest that solutions of fly ash are nearly saturated in Ca(OH/sub 2/). Elements of low to moderate solubility, such as Ca, Mg, SO/sub 4/, and B, showed greater dissolution as the fly ash suspensions were diluted. Ammonium acetate (NH/sub 4/OAc-HOAc) solutions (pH congruent to 5) were found to extract essentially all Ca and S and > 50% of Mg in the fly ash. Substantial fractions of total B in the fly ash were extracted in water (27%) and in an initially acidified (pH = 3) 0.01N NaCl (41.4%). Positive and highly significant correlations were found between total ionic concentration and electrical conductivity of the solution.more » The slope of the straight-line relationship was, however, considerably less than that commonly used in describing soil salinity. It is concluded that aqueous systems of fly ash do not represent a true equilibrium and that there is a need to standardize methods of salinity and base analyses in fly ash.« less
TL;DR: In this article, a sulfate resistance factor for fly ash concrete concretes was proposed based on the chemical composition of fly ash and the ratio (C-5)/F, where C is calcium oxide and F is ferric oxide in percent.
Abstract: Current methods for determining sulfate resistance of fly ash concrete often require several years of testing. An accepted method that can be used to predict sulfate resistance in a few days does not exist. A hypothesis is submitted as a possible step towards development of a comprehensive theory. The sulfate reactivity of fly ash is characterized by its chemical composition. One high calcium fly ash was shown to react similarly to blast-furnace slags. Sulfate resistance of comparable fly ash concretes is shown to correlate with ash composition; therefore, based on chemical composition of fly ash, a sulfate resistance factor R is proposed. The factor is the ratio (C-5)/F, where C is calcium oxide and F is ferric oxide in percent. When R is less than 1.5, a fly ash should improve the sulfate resistance.
Patent•
16 May 1980
TL;DR: In this article, the fly ash is separated from the gas stream by atomizing an aqueous liquid into the hot waste gases in the presence of fly ash suspended in a gas stream.
Abstract: Mercury is removed from a stream of hot waste gases by atomizing an aqueous liquid into the hot waste gases in the presence of fly ash suspended in the gas stream. Subsequently the fly ash is separated from the gas stream. A substantial part of the mercury originally present in the gas stream is absorbed or adsorbed by the fly ash so that the stream of the waste gas can safely be discharged to the atmosphere.
TL;DR: Fly ash samples from two different generating plants have been examined by laser light scattering techniques and each particle appears to have a different refractive index, probably indicative of the varied microscopic conditions of formation.
Abstract: Fly ash samples from two different generating plants have been examined by laser light scattering techniques. Individual particles below ~3-μm diam, found to be primarily spherical, were electrostatically levitated in a single-particle light scattering photometer while their differential light scattering (DLS) patterns were recorded. During this measurement period, the relative humidity within the scattering cell could be varied to study the water accretion properties of the suspended particle. The recorded DLS patterns are used to derive the complex refractive index, size, and accreted layer thickness of the particle. Each particle appears to have a different refractive index, probably indicative of the varied microscopic conditions of formation. Even at very high relative humidities, the fly ash particle surface does not appear to have a natural affinity for water, contrary to popular expectations.
TL;DR: The elemental solubilities of three coal fly ash samples and two coastal marine-aerosol samples in seawater are different as mentioned in this paper, and the coal fly-ash samples were collected from the electrostatic precipitators on coal-fired power plants.
TL;DR: Gas chromatography-high resolution mass spectrometry has been used to quantitate tetrachlorodibenzo-p-dioxin in fly ash collected from the stack of a typical coal-fired power plant, indicating that this type of fossil-fueled power plant is not a large source of this compound in environmental samples, in contrast to the conclusions presented in a recent industrial report.
Abstract: Gas chromatography-high resolution mass spectrometry has been used to quantitate tetrachlorodibenzo-p-dioxin (TCDD) in fly ash collected from the stack of a typical commercial coal-fired power plant. No TCDD was detected in this fly ash, but minute traces may be present below the detection limit of 1.2 parts per trillion (by weight). This finding indicates that this type of fossil-fueled power plant is not a large source of this compound in environmental samples, in contrast to the conclusions presented in a recent industrial report.
TL;DR: In this article, a rotary evaporator was used to separate fly ash and solvent, which was then concentrated to 100 µmL using a Rotary Efficient Rotary Evaporator (RER).
Abstract: Polychlorinated dibenzo-p-dioxins (PCDDs) and other organic compounds are solvent extracted from 10- to 20-g samples of fly ash from municipal incinerators with 200 mL of benzene using ultrasonic agitation for 1 h. A convenient filtering device is used to separate fly ash and solvent which is then concentrated to 100 ..mu..L using a rotary evaporator. Extracts are analyzed directly by gas chromatography/mass spectrometry, including selected ion monitoring for PCDDs. Results from five replicate analyses of a fly ash sample yielded averages and standard deviations (ng/g) for the tetra-to octachlorinated dibenzo-p-dioxins of 8.6 +- 2.2, 15.0 +- 4.0, 13.0 +- 3.4, 3.2 +- 1.0, and 0.4 +- 0.1, respectively. 2 tables, 3 figures.
TL;DR: In this article, the surface deposition models were used to estimate the depth of the surface layer as well as the concentrations of surface-enriched elements in a coal-fired power plant stack fly ash.
TL;DR: In this paper, a linear relation was found between the specific surface of PFA and its pozzolanic activity index while the relation between the amount retained on 45μm sieve was linear only in a limited middle range.
Patent•
13 Mar 1980
TL;DR: In this paper, a gypsum board consisting of a monolithic cellular core of set gypsumin and a fiberous cover sheet encasement provided with improved properties by the core having incorporated coal fly ash in an amount of about 1-20% by weight of stucco in the gypsuma slurry used in forming the board and method of producing the board was disclosed.
Abstract: A gypsum board consisting essentially of a monolithic cellular core of set gypsum and a fiberous cover sheet encasement provided with improved properties by the gypsum core having incorporated therein coal fly ash in an amount of about 1-20% by weight of stucco in the gypsum slurry used in forming the board and method of producing the board are disclosed.
Patent•
03 Mar 1980
TL;DR: In this paper, an improved process for the hydrocracking of heavy hydrocarbon oil, such as oils extracted from tar sands, is described, where charge oil in the presence of an excess of hydrogen is passed through a tubular hydro-cracking zone, and the effluent emerging from the top of the zone is separated into a gaseous stream containing a wide boiling range material and a liquid stream containing heavy hydrocarbons.
Abstract: An improved process is described for the hydrocracking of heavy hydrocarbon oil, such as oils extracted from tar sands. The charge oil in the presence of an excess of hydrogen is passed through a tubular hydrocracking zone, and the effluent emerging from the top of the zone is separated into a gaseous stream containing a wide boiling range material and a liquid stream containing heavy hydrocarbons. According to the novel feature, the charge stock is in the form of a slurry of heavy hydrocarbon oil and finely divided fly ash or high ash coal fines. The presence of this ash in the charge stock serves to greatly reduce coke precursors and thereby prevent the formation of carbonaceous deposits in the reaction zone.
Patent•
17 Jun 1980
TL;DR: In this paper, a method for disposing of spent residue from a fluidized combustion bed of the type in which lime or limestone particles are suspended in a fluidised medium and a carbonaceous fuel is ignited proximate said fluidized medium to capture substantial amounts of SOx which is generated upon ignition of said carbonaceous fuels, the lime component of which has been substantially hydrated by mixing with water, and pozzolanic material such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix.
Abstract: A method, wherein spent residue from a fluidized combustion bed of the type in which lime or limestone particles are suspended in a fluidized medium and a carbonaceous fuel is ignited proximate said fluidized medium to capture therein substantial amounts of SOx which is generated upon ignition of said carbonaceous fuel, the lime component of which has been substantially hydrated by mixing with water, and pozzolanic material, such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix. The mix is cast into desired shape and cured. If desired, the shape may then be crushed so as to result in a fluidized bed combustion residue-fly ash aggregate material or the shape may be used by itself. The method enables a commercially acceptable way of disposing of the spent bed residue by incorporation thereof in a high-strength concrete-like material.
TL;DR: In this article, a selection of ashes produced in a Lurgi gasification plant and fly ash from a pulverized coal combustion were analyzed using IRMS and X-ray diffraction methods.
TL;DR: Dimethyl sulfate and its hydrolysis product monomethyl sulfate have been found at concentrations as high as 830 parts per million in fly ash and in airborne particulate matter from coal combustion processes, posing a new environmental problem.
Abstract: Dimethyl sulfate and its hydrolysis product monomethyl sulfate have been found at concentrations as high as 830 parts per million in fly ash and in airborne particulate matter from coal combustion processes. This discovery poses a new environmental problem because of the mutagenic and carcinogenic properties of these compounds.
Patent•
28 Oct 1980
TL;DR: In this paper, the authors proposed the addition of finely divided (powdered) lime, limestone, or dolomite, and flyash or other pozzolonic material, to finely divided coal (such as the product of a coal cleaning plant) to provide a binder such that the fine coal can easily be formed into durable pellets, agglomerates, briquettes, or other shapes and/or sizes convenient for handling, transporting, or storing using conventional techniques for standard lump coal, and with these same low-cost materials, provide, upon
Abstract: This invention proposes the addition of finely divided (powdered) lime, limestone, or dolomite, and flyash or other pozzolonic material, to finely divided coal (such as the product of a coal cleaning plant) to: (a) provide a binder such that the fine coal can easily be formed into durable pellets, agglomerates, briquettes, or other shapes and/or sizes convenient for handling, transporting, or storing using conventional techniques for standard lump coal, and (b) with these same low-cost materials, provide, upon combustion in a furnace or boiler of appropriate design, with or without prior grinding of the formed coal pieces, a highly dispersed sulfur-capturing agent (sorbent) which, because of its large surface area, high degree of dispersal, and initimate contact with burning coal particles, will efficiently remove gaseous sulfur compounds as they are formed during the combustion process.The lime, limestone, or dolomite incorporated in the binder function also as desulfurzing agents during the combustion process, thereby further minimizing sulfur emissions due to organic sulfur remaining in the cleaned coal; introducing the desulfurizing agent in this form and manner into the combustion chamber provides for highly controllable, highly efficient desulfurization capability and minimum operating problems; and, finally, the potential sulfur pollutants are captured in a form that permits their collection as part of well-established particulate emission (flyash) control procedures which are required anyway, irrespective of coal sulfur content.
TL;DR: In this article, the radionuclide content of coal, bottom ash and fly ash is reviewed and estimates of the quantities of various radionsides released to the environment from coal combustion and the probable resultant radiation doses to the population are made.
Abstract: Data on the radionuclide content of coal, bottom ash and fly ash are reviewed. Estimates are made of the quantities of various radionuclides released to the environment from coal combustion and the probable resultant radiation doses to the population. Factors that influence these dose estimates, such as particle size, solubility and radon emanating power are discussed.