Vamvuka et al. [11] characterized the fly ash and bottom ash (slag) of an biomass fluidized bed boiler, and found the ashes were enriched in Ca, Si, P, K, Mn, Zn, ... In this section, the ash/slag ratio, unburned carbon content, major and trace element compositions, and leaching characteristics of fly ash and slag samples were tested. …
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DOI: 10.1016/J.CONBUILDMAT.2014.05.057 Corpus ID: 137076993; Characteristics of CFBC fly ash and properties of cement-based composites with CFBC fly ash and coal-fired fly ash @article{Wu2014CharacteristicsOC, title={Characteristics of CFBC fly ash and properties of cement-based composites with CFBC fly ash and coal …
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Limestone or dolomite is often added as a adsorbent in circulating fluidized bed boilers [17], [22], ... this paper reviews the pertinent domestic and international literature and introduces the fundamental characteristics of CFB fly ash, including its phase composition and chemical composition. In terms of fresh mixing properties, …
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The first case study is the simulation of the fly ash deposition on superheater and reheater in boilers. The experimental work was carried out by Kalisz and Pronobis [5], and the simulation of Lagrangian approach for the above ash deposit process was done by Wacławiak and Kalisz [3].In the simulations, the tube banks in the superheater and …
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Abstract Currently, in the energy sector circulating fluidized bed boilers are popularly used, resulting in the production of large amounts of fly ash. Due to the limited possibilities of utilization, the development of technology for their processing is crucial. One of the most promising and intensively studied ways to exploit fly ash (including those …
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than fly ash. Boiler slag is black and angular, and has a smooth, glassy appearance. The properties of fly ash and bottom ash make them useful for a variety of construction applica-tions. Table 1 lists ranges for some of the important geotechnical properties of fly ash and bottom ash. Chemical Composition
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A very huge amount of ash is produced from these boilers. The quality of ash varies from plant to plant and from coke to coke depending on source of supply and type of combustion. ... SETTLING CHARACTERISTICS OF FLY ASH The slurry of fly ash i.e bottom ash and fly ash with water is pumped into ash ponds.It is very important to know that the ash ...
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Fly ash and bottom ash of husk fired boilers are considered as solid waste (Chungsangunsit et al., 2009) and are included under impact of solid wastes. This bottom ash inventories in Table 3 were ...
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The characteristics of the combustion ash produced by CFB boilers are significantly different from those of pulverized coal fly ash (PCFA). In addition to the relatively low combustion temperature in CFB boilers [ 12 ], in situ desulfurization and flue gas desulfurization (FGD) systems are widely used in CFB boilers to reduce sulfur …
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Fly ash (FA) is the principal industrial waste byproduct from the burning of solid fuels. FA is a powdery solid that is constituted mostly of unburned carbon (UC), metal oxides (Si, Fe, Ca, and Al), and other inorganic substances. UC is an inexpensive source …
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In this paper, an intensive characterization of ash deposits collected from different positions of a pulverized-coal (PC) boiler has been conducted to diagnose the ash slagging and fouling issues within this boiler and to clarify the mass balance/flow of individual major elements and their role on ash slagging and fouling. A lab-scale drop-tube furnace has …
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As the coal resources are in short supply in recent years, most circulating fluidized bed (CFB) boilers in china burn hard coals such as anthracite, bituminous, low …
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Fly ash demonstrates very good properties for the adsorption of mercury, especially that obtained from fluidized bed boilers due to the presence of unburned carbon [55]. The obtained mercury content in the fly ash 2 sample was relatively high, and extremely high for the fly ash 1 sample, when related to fly ashes obtained from coal …
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The original fly ash used in our experiments was collected from the plant of a 135 MW CFB boiler. Table 2 gives the chemical composition analysis of the limestone and original fly ash analyzed by X-ray fluorescence. The particle size distribution of the original fly ash (Fig. 1) was analyzed by the particle size analyzer (Mastersizer, 2000E).
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Fly ashes produced by FBC boilers are not considered in this document. Fly ash is captured from the flue gases using electrostatic precipitators (ESP) or in filter fabric collectors, commonly referred to as baghouses. ... Uniformity of fly ash characteristics from shipment to shipment is imperative in order to supply a consistent product. Fly ...
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Boiler fly ash and solidified boiler fly ash. The original boiler fly ash (BFA) sample was obtained from a paper mill plant in 2016 in Nichinan City, Japan. The plant incinerates four different types of waste using a fluidized bed incinerator for its energy production processes.
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1. Introduction. Pulverized coal combustion fly ash (PCA) is an industrial by-product of coal-fired power plants, and a large amount of it is produced and discharged globally every year [1], [2], [3].PCA is not only cheaper than cement [4], but it also improves the corrosion resistance and the fluidity of concrete [4], [5], reduces hydration heat [6], …
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Fly ash demonstrates very good properties for the adsorption of mercury, especially that obtained from fluidized bed boilers due to the presence of unburned …
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The effects of the fly ash reburning on element migration and ash deposition characteristics of high-alkali coal in a full-scale slag-tapping boiler were investigated in this work. The results showed that the primary components in different samples were SiO 2, Al 2 O 3, Fe 2 O 3 and CaO.
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In 2007 Zhou [2] numerically investigated the growing and shedding characteristics of fly ash on the cold probe in a biomass fired boiler. In industry, the removal of particles from deposit layer would be affected by fluid flow when the time scale of particle collision is bigger than that of pulsation in the flow field.
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The bottom ash was sampled from the outlet of the boiler and the fly ash from the boiler's electrostatic precipitator. The sampling was carried out over a period of five days, and the individual samples (i.e. 1 kg/day) were combined to give one composite sample with a weight of 5 kg (wet weight).
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Industrial experiments were carried out to investigate the influence of fly ash recirculation rate on combustion performance and pollutant emission characteristics of the boiler. Results show that with FARBF, the dense bed temperature drops while the furnace exit temperature increases, the temperature distribution in the furnace becomes uniform.
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As the mineral constituent of the fly ash of a CFB boiler is different from that of a pulverized coal-fired one, the use of the loss-on-ignition method for measuring carbon content of the fly ash ...
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The maximum carbon content of fly ash of pulverized coal furnace is 4.89%, and the minimum carbon content is 1.98%, both less than 5%, and the carbon content of fly ash decreases gradually with ...
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Coal-fired fly ash was used for partial cement replacement by weight. The specific gravity of coal-fired fly ash is 2.39. The blaine specific surface area was 4050 cm 2 /g. Coal-fired fly ash contains significantly higher amounts of silicon dioxide (SiO 2), aluminum oxide (Al 2 O 3), and ferric oxide (Fe 2 O 3).The chemical compositions of …
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The ignition temperature of combustible fly ash in various conditions was obtained, the ignition characteristics of combustible fly ash in the airflow were …
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than fly ash. Boiler slag is black and angular, and has a smooth, glassy appearance. The properties of fly ash and bottom ash make them useful for a variety of construction applica tions. Table 1 lists ranges for some ofthe important geotechnical properties of fly ash and bottom ash. Table 1.
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In addition, other parameters, such as carbon content of the reburnt fly ash, the ratio of the reburnt fly ash amount to other coals fed into the boiler, have a major influence on the combustion ...
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@article{Ni2023ResearchOT, title={Research on the effects of the fly ash reburning on element migration and ash deposition characteristics of high-alkali coal in a full-scale slag-tapping boiler}, author={Yuguo Ni and Shihao Hu and Yize Zhang and Mingrui Zhang and Haiyang Li and Hao Zhou}, journal={Fuel}, year={2023}, url={https://api ...
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Fly ash with different volatile contents was used to systematically study the ignition characteristics and influencing factors of fly ash in flue gas and to analyze the …
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One of the consequences is an increase in the emission of fly ash and volatile (trace) particles; this emission has been studied for utility boilers that are fired with pulverized coal. The relevant parameters are (1) the type of boiler, (2) the ash-collection devices employed and (3) the type of coal.
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The unburned carbon content in the fly ash is complicated and it is affected by many factors, such as coal character, boilers load, air distribution, boiler style, burner style, furnace ...
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This study takes a 330 MW four-corner tangential coal-fired boiler as an example to conduct research. The width of the boiler furnace is 13.26 m, the depth is 12.96 m, and the height is 52.50 m. The main burner has 12 layers of nozzles, of which 4 layers are primary air nozzles and 8 layers are secondary air nozzles.
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Petrographic characteristics of fly ash from different coal-fired boilers. A: Unburned carbon debris and small angular quartz particles embedded in baked rocks in FA-1. B: Fine spinel in glass matrix and glass cenospheres nearby in FA-2. C: Partially heat clay and amorphous glass phase in FA-1.
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Formation of Fly Ash. Fly ash is formed during the coal burning process in the boiler. Fly ash material solidifies while in suspension in the exhaust gases and is collected by electrostatic precipitators or filter bags. Since the particles are generally spherical in shape and range in size from 0.5 µm to 100 µm.
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The effects of the fly ash reburning on element migration and ash deposition characteristics of high-alkali coal in a full-scale slag-tapping boiler were investigated in this work. ... a fly ash reburning system can be equipped on the slag-tapping boiler. The fly ash collected by the electrostatic precipitator is reburned with coal to increase ...
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