Patent Number: 6,254,981

Title: Fused glassy particulates obtained by flame fusion

Abstract: The disclosure describes methods for producing bulk, particulate material that includes solid, generally ellipsoidal particles. Irregularly shaped feed particles with average particle sizes of up to 25 microns on a volume basis are dispersed in at least a portion of a combustible gas mixture by application of force and/or fluidizing agents. The combustible mixture with particles in suspension is then delivered, while controlling agglomeration or re-agglomeration of the particles, to at least one flame front. There, the mixture and suspended particles are uniformly distributed across the surface(s) of and passed through the flame front(s) with a high concentration of particles in the mixture. This flame front and the resultant flame(s) with suspended particles are located in at least one "wall free" zone. In such zone(s) the flame(s) may expand while the particles are maintained in dispersion and heated, with controlled and highly efficient application of heating energy. At least partial fusion occurs within at least the surfaces of the particles at high thermal efficiencies, while agglomeration of particles during fusion is inhibited.

Inventors: Castle; Richard B. (Keizer, OR)

Assignee: Minnesota Mining & Manufacturing Company

International Classification: B01J 2/16 (20060101); B01J 8/18 (20060101); B01J 6/00 (20060101); C03B 19/00 (20060101); C03B 19/10 (20060101); C03C 12/00 (20060101); B32B 005/16 (); C08K 007/16 (); C08K 003/40 ()

Expiration Date: 07/03/2018