Composition, mineral matter characteristics and ash fusion behavior of some Indian coals

Chakravarty, Sanchita; Mohanty, Ashok; Banerjee, Amit; Tripathy, Ruchira; Mandal, G. K.; Basariya, M. Raviathul; Sharma, Mamta

doi:10.1016/j.fuel.2015.02.015

Cited by 69 publications

(37 citation statements)

References 20 publications

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“…Coal at higher depth (M43 seam) was of relatively low quality having highest ash yields (58.53 %) and lowest GCV (2810 cal/g). Our earlier study also indicated that coal quality varied significantly from one seam to other for Indian coals (Chakravarty et al 2015). It is also observed that V ad (%) and S ad (%) decrease with increase in depth.…”

Section: Coal Quality and Mineralogysupporting

confidence: 56%

“…Recently, the process of phase transformation of mineral matter during coal combustion and gasification has been studied by some researchers. Chakravarty et al (2015) have investigated the composition, mineral matter characteristics and ash fusion behavior of some Indian coals. FactSage thermodynamic model was used to understand ash fusion behavior and to predict the phase transformation that occurs during the process of coal combustion.…”

Section: Introductionmentioning

confidence: 99%

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Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

Banerjee

Mishra

Mohanty

et al. 2016

Int J Coal Sci Technol

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Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal ([50 %) and volatile matter deceases along with the seam depth. XRD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals (kaolinite, silimanite, illite) decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams (M2, M12, M24 and M43) studied, ash of M43 has high Al 2 O 3 %, TiO 2 % and K 2 O% content and low SiO 2 %, CaO% and MgO% content. High acidto-base ratios contributed to high ash fusion temperatures (IDT [ 1500°C) and low slagging potential of the coals studied. Relatively low fouling index (\0.3) was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500°C during coal combustion.

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Section: Coal Quality and Mineralogysupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

Banerjee

Mishra

Mohanty

et al. 2016

Int J Coal Sci Technol

Self Cite

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“…These authors used a neural network method, i.e., ACO-BP neural network based on ant colony optimization, to predict the AFT. Chakravarty et al [21] used thermodynamic modeling to predict and understand ash fusion behavior and Winegartner and Rhodes [22] used regression analysis to calculate AFT of coal ash from chemical composition. The possibility exists that damring formation can also be caused by partial melting of pellets being fed into the kiln and/or pellet fragments formed in the kiln.…”

Section: Introductionmentioning

confidence: 99%

Damring Formation During Rotary Kiln Chromite Pre-reduction: Effects of Pulverized Carbonaceous Fuel Selection and Partial Pellet Melting

Staden

Beukes

Zyl

et al. 2018

Metall Mater Trans B

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Electricity consumption is the largest cost contributing factor in the production of ferrochrome. Currently the pelletized chromite pre-reduction process (solid-state reduction of chromite) is the process option with the lowest specific electricity consumption (MWh/ton). In this process, pelletized chromite is fed into a rotary kiln at 1573 K (1300°C), where partial pre-reduction takes place. Damring formation (material build-up) in the rotary kiln causes routine shutdowns, resulting in loss of revenue. The damring formation is possibly caused by melting of the ash of the pulverized coal used to fire the kiln and/or the partial melting of the chromite pellets. Ash fusion temperatures of twenty different samples were evaluated to assess the temperature at which the pulverized coal ash will start to contribute to damring formation. Sessile drop tests were used to assess the softening behavior of different ore types (e.g., UG2, MG, and LG metgrade), as well as softening of composite chromite pellets made from these ores. Actual damrings were also analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy. Results indicate that it is mainly the pulverized coal ash that will contribute to damring formation, and not ore or pellet softening. Multiple-linear regression was used to derive equations to predict the ash fusion temperatures of the pulverized coal ash, which can be used by ferrochrome producers to optimize pulverized coal selection.

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“…The mechanical or pressure drop tests [11] seem to be more adequate because they are based on change of physical properties (mechanical strength and porosity) associated with the ash microstructure. Regarding to chemical reactions and phase transitions, tests based on phase equilibrium calculations [12][13][14][15][16] may be the way more appropriate.…”

Section: Introductionmentioning

confidence: 99%

Dielectric loss factor of sintered coal ash

2017

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Abstract. This work presents the study of dissipation factor (tanδ) for ash prepared from a power plant coal. Values of tanδ were measured for samples of coal ash with additive of biomass and kaolinite, sintered at various temperatures up to 1100 o C. Procedure of direct tanδ measurement is described and the results of loss factor as a function of frequency are shown. Quantitative and qualitative changes of tanδ were observed for the different tested samples. The measurement data is compared with SEM microscopic images of the samples sintered at the maximum temperature. The results suggest that direct measurement of tanδ can be a useful tool for slagging and fouling risk assessment.

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Composition, mineral matter characteristics and ash fusion behavior of some Indian coals

Cited by 69 publications

References 20 publications

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

Damring Formation During Rotary Kiln Chromite Pre-reduction: Effects of Pulverized Carbonaceous Fuel Selection and Partial Pellet Melting

Dielectric loss factor of sintered coal ash

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