Spheroidal slag and fly ash particles and apparatus and process for producing same
AssigneeBlack Diamond Granules, Inc.
InventorPaul W. Meyer
Life of this patent
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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.
Claims21
A process for spherulizing irregularly shaped particles of coal fly ash or coal slag comprising the steps of:
- (a) delivering a feedstock of irregularly shaped particles of coal fly ash or coal slag to a drop tube having an upper portion, a central portion, and a lower portion;
- (b) dropping the irregularly shaped particles into said upper portion of said drop tube in a manner such that the irregularly shaped particles flow in a substantially vertical downward path through said drop tube as individualized particles;
- (c) heating the irregularly shaped particles to a sufficient temperature by providing heat to said central portion of said drop tube to cause at least the outer surface of the irregularly shaped particles to melt such that a majority of the irregularly shaped particles become spheroidal particles due to surface tension at the outer surface;
- and
- (d) allowing the spheroidal particles to cool within said lower portion of said drop tube;
- and
- (e) crushing said spheroidal particles.
A process for spherulizing and hollowing irregularly shaped particles of coal fly ash or coal slag comprising the steps of:
- (a) delivering a feedstock of irregularly shaped particles of coal slag or coal fly ash to a drop tube having an upper portion, a central portion, and a lower portion;
- (b) adding to the feedstock a material which on heating generates H2O, NO, NO2, SO3, CO2, or mixtures thereof;
- (c) dropping the irregularly shaped particles into said upper portion of the drop tube in a manner such that said particles flow in a substantially vertical downward path through the drop tube as individualized particles;
- (d) heating the irregularly shaped particles to a sufficient temperature by providing heat to the central portion of said drop tube to cause at least the outer surface of the irregularly shaped particles to melt such that a majority of the irregularly shaped particles become spheroidal particles due to surface tension at the outer surface;
- (e) forming hollow regions within the spheroidal particles by heating due to the presence of H2O, NO, NO2, SO3, CO2, or mixtures thereof;
- and
- (f) allowing the spheroidal particles to cool within the lower portion of the drop tube.
Dependencies are inferred from the claim text.