Determination of pyritic sulphur and organic matter contents in Spanish subbituminous coals by X-ray power diffraction

Querol, Xavier; Alastuey, Andrés; Chinchón, J. S.; Fernández-Turiel, J. L.; Soler, Ángel López

doi:10.1016/0166-5162(93)90030-e

Cited by 27 publications

(14 citation statements)

References 8 publications

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“…Two varieties of anhedral pyrite were observed in Pernik subbituminous coals. Replacement anhedral pyrite results from either the mineralization of cell walls (Wiese & Fyfe 1986) or massive pyritic replacement of organic matter (Querol et al 1989). The other variety is infilling anhedral pyrite, which fills cell lumens and pores in the plant debris.…”

Section: Anhedral Pyritementioning

confidence: 99%

Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin

Kostova

Petrov

1996

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The mineralogy and geochemistry of Pernik subbituminous coals (coal bed A) and some genetic peculiarities related to the mineral formation were studied. The mineral matter of the coal consists chiefly of pyrite, kaolinite, siderite, quartz and calcite. Other minerals (dolomite, ankerite, plagioclase and some sulphates) are present in minor amounts, some occurring as accessory single crystals. Pyrite is the main mineral in these coals and exhibits a large array of textures and morphology. Isolated and clustered euhedral, bacterial and inorganic framboidal, cluster-like, homogeneous and microconcretional massive, infilling and replacing anhedral, and cleat-filling and fracture-filling infiltrational pyrite types were observed. Four stages of mineralization were distinguished: pyrite-kaolinite, pyrite, pyrite-siderite and sulphate stages. The amount of pyrite present in two sections of coal bed A was determined by quantitative powder X-ray diffraction analysis. The concentrations of 37 trace elements were determined. As, Cu, Co, Ni, Zn, Pb, V Ti, Mo, Rb, Cr and Mn are typomorphic for this coal. On the basis of their relation to organic or inorganic matter, four groups of trace elements were subdivided; and on the basis of cluster analysis four associations were differentiated.

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Section: Anhedral Pyritementioning

confidence: 99%

Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin

Kostova

Petrov

1996

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“…The Reference Intensity Method (Chung, 1974(Chung, a, b 1975) using fluorite as the reference standard, was the method used for the XRD quantitative analysis. The XRD quantitative method used in this study is described in Querol et al (1993). The Reference Intensity Method is based on the following equation:…”

Section: Methodsmentioning

confidence: 99%

The behaviour of mineral matter during combustion of Spanish subbituminous and brown coals

1994

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The concept of force of crystallization is combined with that of depression of dissolution to explain diagenetic volume-for-volume replacement in both cases, either when the pressure is increased in early sedimentary settings, or when it is diminished in a late exposure. Also, a new textural criterion is added to the three classical ones in order to recognize diagenetic volume-for-volume replacement, and calculations are carried out to estimate the speed of the replacement.

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“…• C. 22 However, XRD mineralogy (Table 4) revealed that in 13 Thus the fly ashes are aluminosilicious with pozzolanic activity 5 and are useful as components of building materials. Anhydrite (CaSO 4 ), which occurs in other fly ashes 23 as a result of the reaction of CaO with sulfur dioxide, is not found in the present work.…”

Section: Results and Discussion Chemical Composition And Loss On Ignimentioning

confidence: 98%

“…Quartz is the only mineral phase of coal that remains stable during the combustion process at 750 • C. 22 However, XRD mineralogy (Table 4) revealed that in addition to the main mineral phases in the bulk fly ashes (amorphous silica, mullite and quartz), calcite (CaCO 3 ) and illite (K(Al, Mg) 3 SiAl 10 OH) were also detected in the fly ash products. The presence of mullite (Al 6 Si 2 O 13 ) in the samples is probably due to thermal transformation of aluminosilicate.…”

Section: Particle Size Distribution and Mineral Compositionmentioning

confidence: 99%

Comparative assessment of Australian fly ash and conventional concrete bricks

Ayoko

Lim

Olofinjana

et al. 2004

J of Chemical Tech & Biotech

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A comparative study of the chemical composition, mineralogy, morphology and crushing strengths of fly ash bricks, conventional concrete bricks and fly ash samples has been undertaken. The main chemicals present in the products were silica and alumina while their main minerals were quartz, mullite, illite, vaterite, and calcite. Elemental analysis by XPS showed that the major elements in the samples were oxygen, silicon, carbon, calcium and aluminium; and scanning electron microscopy revealed that the fly ash samples consist of spherically-shaped particles with surface attachment containing needlelike particles. Compared with conventional concrete bricks, fly ash bricks generally have higher atomic silicon and crushing strengths but lower crystalline silica. The implication of the results on the suitability of fly ash bricks as replacements for conventional concrete bricks in the building industry is discussed from the point of view of human health and occupational safety.

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Determination of pyritic sulphur and organic matter contents in Spanish subbituminous coals by X-ray power diffraction

Cited by 27 publications

References 8 publications

Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin

Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin

The behaviour of mineral matter during combustion of Spanish subbituminous and brown coals

Comparative assessment of Australian fly ash and conventional concrete bricks

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