Abstract: The present invention provides spheroidal particles from slag and ash. The spheroidal particles are formed by dropping particles of slag and ash through a heated zone which fuses at least an outer surface of the particles.

Abstract: The present invention provides spheroidal particles of coal slag, and methods of making the spheroidal particles. One method of the invention includes delivering a feedstock of irregularly shaped particles of coal fly ash or coal slag to a drop tube, dropping the irregularly shaped particles into the drop tube in a manner such that the irregularly shaped particles flow in a substantially vertical downward path as individualized particles, and heating the irregularly shaped particles to cause at least the outer surface of the irregularly shaped particles to melt and form spheroidal particles due to surface tension at the outer surface. The spheroidal particles typically have a diameter in the range of about 0.001 to 5 mm, and comprise SiO2, Al2O3, Fe2O3, FeO, Na2O, and K2O.

Abstract: The present invention provides spheroidal particles of coal slag. The spheroidal particles have at least a hard outer shell, a diameter in the range of about 0.001 mm to 5 mm and comprise SiO2, Al2O3, Fe2O3, FeO, CaO, Na2O and K2O. The present invention also provides a process for spherulizing irregularly shaped particles of coal slag and agglomerated coal fly ash. The process includes the steps of: (a) providing a drop tube having an upper portion, a central portion and a lower portion; (b) deliverng a feedstock of irregularly shaped particles of coal slag and agglomerated coal fly ash to the upper portion of the drop tube at a rate at which the particles remain individualized; (c) heating the particles to a sufficient temperature by providing heat to the outer surface of the central portion of the drop tube to cause at least the outer surface of the particles to melt such that a majority, i.e.