Energy sources. Part A, Recovery utilization and environmental effects
Paginering:
Jaargang 12 (1990) nr. 1 pagina's 33-55
Jaar:
1990
Inhoud:
Energy-dispersive x-ray detection of elements from scanning electron microscopy (SEM-EDX) was used to determine amounts of elements in coal macerals. X-ray diffraction (XRD) was used to determine minerals in the low temperature ashes of the coals. SEM-EDX elemental assemblages in grains and the body of the coal were assigned to mineral categories using XRD results. Macerals were determined petro-graphically. Most nonorganic elements were found in minerals. Organically associated elements such as Cl, Cs, Cr, P, organic sulfur (So), Sc, and V were consistently found in the coal matrix. Inorganically associated elements such as Al, Ca, Mg, and Si were also commonly found in the matrix. Vitrinitelhuminite (V/H) maceral matrix had higher levels of sulfur than the inertinite and liptinite maceral matrix. Low temperature ashing of the pellet surface accentuated the higher levels of Si and Al intimately mixed with the V/H matrix compared to inertinites (I) or liptinites (L). Fusinites (I) often had no nonorganic cations associated with the matrix. Most elements and minerals were found in discrete grains or associated with inertinite macerals. Low temperature ashing revealed that most minerals were concentrated along cracks and around pores. Ashing also resulted in complete oxidation of many fusinites (I), inability to find liptinites (L), major increases of gypsum in V/H and I, losses ofCaP (Apatite) in I combined with increases in complex phosphates, losses of quartz from 1, and losses of potassium silicates (Mite) and Ca (calcite) from V/H.
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