Characterization of the low-temperature ash component of the herrin 6 coal seam (southwestern illinois) by thermal methods of analysis

Effect of Carbonisation Conditions on Mineral Matter in Coke

“…27) Pyrite (FeS 2 ) is the main source of pyrrhotite (Fe 1Ϫx S). 9,28) Metallic iron (Fe) was formed either by further decomposition of pyrrhotite 9) or due to the decomposition of iron carbonate (FeCO 3 ) in a reducing atmosphere. 22) Calcite (CaCO 3 ) loses carbon dioxide to form calcium oxide (CaO) 27,28) which in turn can scavenge sulfur released from pyrite or the organic part of the coal to form oldhamite (CaS).…”

“…9,28) Metallic iron (Fe) was formed either by further decomposition of pyrrhotite 9) or due to the decomposition of iron carbonate (FeCO 3 ) in a reducing atmosphere. 22) Calcite (CaCO 3 ) loses carbon dioxide to form calcium oxide (CaO) 27,28) which in turn can scavenge sulfur released from pyrite or the organic part of the coal to form oldhamite (CaS). 6) Bassanite (CaSO 4 · 0.5H 2 O), jarosite ((K, H 3 O)Fe 3 (SO 4 ) 2 (OH) 6 ) and coquimbite (Fe 2 (SO 4 ) 3 · 9H 2 O) are believed to be artefacts of the ashing process, 21) formed most likely from the oxidation of oldhamite and pyrrhotite, respectively.…”

Mineral matter in coals and their reactions during coking

“…The low-temperature ashing (LTA) procedure was used for the removal of the organic matter in this work. This procedure is widely used and is also a reliable method because it has minimal effect on the mineral matter species (Gluskoter et al, 1981;Earnest, 1987;Ward, 2002). The low-temperature ashing procedure has been described elsewhere (Grigore et al, 2006).…”

“…Pyrite is the main source of pyrrhotite in coke (Earnest, 1987;Kerkkonen et al, 1996). Metallic iron can be formed either by further decomposition of pyrrhotite (Kerkkonen et al, 1996) or the decomposition of siderite.…”

“…Calcite loses carbon dioxide to form calcium oxide (Nankervis and Furlong, 1980;Earnest, 1987) which in turn can scavenge sulfur released from pyrite or the organic part of the coal to form oldhamite (Kerkkonen, 1997). Oldhamite formation is more likely to occur than anhydrite under the reducing conditions in the coke oven.…”