Geochemical evaluation and characterization of a Pittsburgh No. 8 and a Rosebud seam coal

Abstract

Detailed chemical and mineralogical analysis of a bituminous high-volatile A coal from the Pittsburgh No. 8 seam and a Montana sub-bituminous coal from the Rosebud seam was conducted. Analytical determinations over 70 elemental and other coal parameters were made on the whole coals, 3/8 x 28 mesh fractions, six float-sink fractions, and on acid demineralized mineral-free products for each sample. Low-temperature ashes (plasma ashing at approximately 150/sup 0/C) were prepared from the whole coals and their float-sink fractions, and the major mineral phases were determined. Using low-temperature ash (mineral matter) values, organic affinity curves were prepared, and the trace elements were further correlated with the mineral phases. The whole coals were also extracted with an ion exchange solution to ascertain the form in which trace elements were contained in various fractions. Petrographic studies were made of the whole coal and the 3/8 by 28 mesh fraction to investigate the physical relationships of the various macerals.