Experimental Study on the Effects of Chemical and Mineral Components on the Attrition Characteristics of Coal Ashes for Fluidized Bed Boilers

Wang, Tao; Yang, Hairui; Wu, Yuxin; Liu, Qing; Lv, Jingxiang; Zhang, Hai

doi:10.1021/ef201332p

Cited by 12 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given the iron contents and the test phenomenon, all magnetic fractions of CA1 and CA2 were represented by the results of a magnetic separation experiment with 5A and accounted for 2.61% and 2.51%. Those results are consistent with the fact that iron oxide or hematite in fly ash was the dominant occurrence of iron when combusted at 800–900 °C [ 33 ]. On the contrary, CA3 was divided into six fractions by magnetic separation with different magnetic field intensities.…”

Section: Resultssupporting

confidence: 87%

The Discrepancy between Coal Ash from Muffle, Circulating Fluidized Bed (CFB), and Pulverized Coal (PC) Furnaces, with a Focus on the Recovery of Iron and Rare Earth Elements

et al. 2022

View full text Add to dashboard Cite

Coal ash (CA) is not only one of the most solid wastes from combustion, easily resulting in a series of concerns, but it is also an artificial deposit with considerable metals, such as iron and rare earth. The variation in the coal ash characteristics due to the origins, combustion process, and even storage environment has been hindering the metal utilization from coal ash. In this study, three ash sample from lab muffle, circulating fluidized bed (CFB), and pulverized coal (PC) furnace was derived for the discrepancy study from the combustion furnace, including properties, iron, and rare earth recovery. The origins of the coal feed samples have more of an effect on their properties than combustion furnaces. Magnetic separation is suitable for coal ash from PC because of the magnetite product, and the iron content is 58% in the Mag-1 fraction, with a yield of 3%. The particles in CA from CFB appear irregular and fragmental, while those from PC appear spherical with a smooth surface. The results of sequential chemical extraction and observation both indicated that the aluminosilicate phase plays an essential role in rare earth occurrences. Rare earth in CA from muffling and CFB is facilely leached, with a recovery of approximately 50%, which is higher than that from PC ash. This paper aims to offer a reference to easily understand the difference in metal recovery from coal ash.

show abstract

Section: Resultssupporting

confidence: 87%

The Discrepancy between Coal Ash from Muffle, Circulating Fluidized Bed (CFB), and Pulverized Coal (PC) Furnaces, with a Focus on the Recovery of Iron and Rare Earth Elements

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The quartz and mullite content in all fly ash samples, indicated by the combined FTIR and XRD analysis, indicate that all fly ash samples have surface site terminals Al–OH and Si–OH, which can serve as water binding sites for adsorption processes. − The formation of mullite, the fly ash main component in all samples, is consistent with the combustion process of aluminosilicate frameworks contained in coal. During the combustion process, clay components of coal are transformed in a first step into meta-clay, a pseudoamorphous aluminosilicate structure, , followed by a second combustion step to form mullite . Metakaolin (Al 2 O 3 ·2SiO 2 ) and metaillite (KAl 2 AlSi 3 O 11 ), from the initial combustion of kaolinite and illite, respectively, continue to combust above 1700 K as described by reactions and : …”

Section: Methodsmentioning

confidence: 99%

Water Adsorption Isotherms on Fly Ash from Several Sources

et al. 2017

View full text Add to dashboard Cite

In this study, horizontal attenuated total reflection (HATR) Fourier-transform infrared (FT-IR) spectroscopy was combined with quartz crystal microbalance (QCM) gravimetry to investigate the adsorption isotherms of water on fly ash, a byproduct of coal combustion in power plants. Because of composition variability with the source region, water uptake was studied at room temperature as a function of relative humidity (RH) on fly ash from several regions: United States, India, The Netherlands, and Germany. The FT-IR spectra show water features growth as a function of RH, with water absorbing on the particle surface in both an ordered (ice-like) and a disordered (liquid-like) structure. The QCM data was modeled using the Brunauer, Emmett, and Teller (BET) adsorption isotherm model. The BET model was found to describe the data well over the entire range of RH, showing that water uptake on fly ash takes place mostly on the surface of the particle, even for poorly combusted samples. In addition, the source region and power-plant efficiency play important roles in the water uptake and ice nucleation (IN) ability of fly ash. The difference in the observed water uptake and IN behavior between the four samples and mullite (3AlO·2SiO), the aluminosilicate main component of fly ash, is attributed to differences in composition and the density of OH binding sites on the surface of each sample. A discussion is presented on the RH required to reach monolayer coverage on each sample as well as a comparison between surface sites of fly ash samples and enthalpies of adsorption of water between the samples and mullite.

show abstract

“…Thus, to increase combustion development, the whole process needs to be optimized in terms of efficiency and cost. Because of this necessity, developing research has focused on three main aspects: the fuel properties, boiler characteristics, and emissions [4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Biomass Fuel and Combustion Conditions Selection in a Fixed Bed Combustor

et al. 2013

View full text Add to dashboard Cite

Abstract:The biomass market has experienced an increase in development, leading to research and development efforts that are focused on determining optimal biofuel combustion conditions. Biomass combustion is a complex process that involves divergent parameters and thus requires the use of advanced analysis methods. This study proposes combining grey relational analysis (GRA) and error propagation theory (EPT) to select a biofuel and its optimal combustion conditions. This research will study three biofuels that are currently used in a region of South Europe (Spain), and the most important variables that affect combustion are the ignition front propagation speed and the highest temperature that is reached at the fixed bed combustor. The results demonstrate that a combination of both theories for the analysis of solid-state thermochemical phenomena enables a fast and simple way of choosing the best configuration for each fuel.

show abstract

Experimental Study on the Effects of Chemical and Mineral Components on the Attrition Characteristics of Coal Ashes for Fluidized Bed Boilers

Cited by 12 publications

References 12 publications

The Discrepancy between Coal Ash from Muffle, Circulating Fluidized Bed (CFB), and Pulverized Coal (PC) Furnaces, with a Focus on the Recovery of Iron and Rare Earth Elements

The Discrepancy between Coal Ash from Muffle, Circulating Fluidized Bed (CFB), and Pulverized Coal (PC) Furnaces, with a Focus on the Recovery of Iron and Rare Earth Elements

Water Adsorption Isotherms on Fly Ash from Several Sources

Biomass Fuel and Combustion Conditions Selection in a Fixed Bed Combustor

Contact Info

Product

Resources

About