Spheroidal slag particles and apparatus and process for producing spheroidal slag and fly ash particles
US6258456A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1998 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Jan 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2993
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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 SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3, FeO, CaO, Na.sub.2 O and K.sub.2 O. 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., at least 50 weight percent, of the particles become spheroidal due to surface tension; and (d) cooing the particles, preferably in the lower portion of the drop tube, to prevent agglomeration. The present invention further provides an apparatus for sp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.