Characterization of stoker ash from the combustion of high-lanthanide coal at a Kentucky bourbon distillery

Abstract Lanthanide- and yttrium-bearing minerals were examined by transmission electron microscopy - energy-dispersive spectroscopy (TEM-EDS) and related diffraction techniques in the combustion ash produced from the burning of an eastern Kentucky coal in a stoker boiler. The feed coal has nearly 2000 ppm and the stoker ash has over 1400-ppm lanthanides + Y + Sc In one section, zircon with trace amounts of Y was noted. Hafnium was noted in the preliminary scanning electron microscopy - EDS examination of a zircon. In the TEM procedure, the Hf peaks overlap with other peaks and, thus, the presence of Hf could not be confirmed. Both La-, Ce-, Nd-monazite and a La-, Ce-bearing Ti-Fe mineral were observed in the ash. The latter mineral corresponds both in composition and in aspects of the diffraction pattern to crichtonite or davidite or loveringite, all minerals within the Dana-class crichtonite group.