Mineralogy of ash of some American coals: variations with temperature and source

Mitchell, Richard S.; Gluskoter, H.J.

doi:10.1016/0016-2361(76)90001-6

Cited by 113 publications

(51 citation statements)

References 2 publications

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“…The volume percentages of carbon monoxide and carbon dioxide in (nnncb) 83 the product gases from steam gasification did not change over the duration of each run made, ~ut the percentages did vary from one run to another. For the reaction of chnrs produced from the rnw nod t:n(-++),.…”

Section: Extent Of Burn-offsmentioning

confidence: 99%

Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references]

Hippo¹,

Walker²

1977

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Section: Extent Of Burn-offsmentioning

confidence: 99%

Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references]

Hippo¹,

Walker²

1977

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“…One of the most characteristic changes is the formation of amorphous metakaolin due to the loss of OH from kaolinite at ca 450°C, followed by conversion to mullite at a temperature of N 950°C. Above 1200°C, all clay minerals fuse to form glass (Mitchell and Gluskoter, 1976;Ward, 2002). Lime (CaO), and periclase (MgO) are formed as a result of calcite and dolomite decomposition.…”

Section: Introductionmentioning

confidence: 99%

Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Jelonek

Mirkowski

2015

International Journal of Coal Geology

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“…The behaviour of minerals of coal in heating have been widely studied for individual coals. Mitchell and Gluskoter (1976) examined minerals released from coal by means of low temperature ashing (LTA) by slowly heating the released minerals on a hot stage quenching and analysing. Stinespring (1977) repeated the experiments with LTA in a combustor at high heating rates.…”

Section: Introductionmentioning

confidence: 99%

Mineral transformation during combustion of coal blends

Qiu

Chen

1999

Int. J. Energy Res.

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Mineral behaviour for two individual coals (I, J) and their two‐component coal blends and 800°C ash blends heating were studied. Ash samples were heated progressively from 800°C to IT (initial deformation temperature) at 100°C intervals under different conditions. Coal samples were heated from room temperature to the corresponding temperature. Mineral transformation at each temperature was determined by X‐ray diffraction and SEM measurements. The results show that Si, Al, Fe and Ca compounds have a great form variation during heating. Their forms at different temperatures depend on the chemical composition of the ash, the blending ratio and the atmosphere. For different coal ashes, the main mineral matters at 800°C were quartz, anhydrite, hematite, calcite and feldspar. As the temperature increased, oxidation, thermal decomposition, transformation and reaction occurred between the components. Comparing a 40% I+60% J ash blend with individual ashes, fayalite was formed at 1100°C for the blend; the reaction product existed in a glassy phase at 1300°C. For a coal blend having the same ash ratio as the ash blend, FeO reacted with amorphous SiO2 or Al2O3 to form fayalite and hercynite at 1000°C. As the temperature increased to 1100°C, fayalite and hercynite increased obviously. At 1200°C, some iron inclusion compounds melted to become glassy phase matter. Compared with the ash blend, iron species undergo a different change during coal blend heating: fayalite and hercynite formed earlier, iron compounds melted to form a glassy phase at lower temperature. This may be caused by early combustion of the more reactive coal (J coal) in the blend inducing local variation in oxygen concentration gradients around the less reactive coal and consequently affecting the reaction atmosphere and Fe mineral behaviour and interaction. That is to say, for coal blends, the mineral transformation was affected by both the mineral species interaction and the combustion behaviour. The calculations were performed to examine the fate of mineral matter under different combustion conditions using a thermodynamic chemical equilibrium calculation program. Calculations from coal blends were comparable with experiments from ash blends, this is because the calculation program only considers the interaction among the mineral species but does not consider the combustion reaction. It indicates that combustion and the relative volatiles also affected the mineral behaviour and slagging during coal blend combustion. Meanwhile, the mineral species evaporations were measured at high temperature: the main evaporated species were Na, K pure species and compounds, Fe, FeO, SiO and SiO2. The evaporation of Fe has an important effect on initial deposition. Calculations were comparable with the experiments. Copyright © 1999 John Wiley & Sons, Ltd.

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Mineralogy of ash of some American coals: variations with temperature and source

Cited by 113 publications

References 2 publications

Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references]

Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references]

Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Mineral transformation during combustion of coal blends

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