Process of manufacturing hollow spherical glass particles
AssigneeOmya International AG
InventorsGerhard Olbert, Laila Raquel Pasin E Matos, Ekaterina Helwig
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Abstract
Process for the preparation of hollow spherical glass particles comprising at least SiO2, Al2O3, and an alkali metal oxide, wherein the process comprises the preparation of precursor particles comprising at least SiO2, Al2O3, and an alkali metal oxide by mixing the starting materials, slurrying the starting materials with water followed by spry-drying and heat-treating the obtained precursor-particles at a temperature from 1000° C. to 1800° C., preferably from 1300° C. to 1600° C. by contacting the precursor particles with at least one naked flame.
Claims11
A process for the preparation of hollow spherical glass particles comprising at least SiO2, Al2O3, and an alkali metal oxide, comprising at least the steps of
- (I) preparing precursor-particles by a process comprising at least the following substeps
- (I-1) providing a starting composition comprising particles of at least one starting compound for forming a glass which comprises at least SiO2, Al2O3, and an alkali metal oxide,
- (I-2) mixing the starting composition with a liquid, thereby obtaining a slurry, and
- (I-3) spray drying the obtained slurry, thereby obtaining the precursor-particles, and
- (II) heat-treating the precursor-particles at a temperature from 1000° C. to 1800° C. by passing the precursor-particles through a heating device, thereby obtaining hollow spherical glass particles,
- wherein at least one naked flame fed by a flammable gas is burning in an interior of the heating device, and the heat-treatment is carried out by contacting the precursor-particles with the naked flame(s),
- wherein the precursor-particles are dispersed in the flammable gas which feeds the flame(s) in the heating device and/or the precursor-particles are dispersed in a non-flammable gas which is added into the heating device at a position upstream of the flame(s), and
- wherein the heating device comprises a plurality of burner nozzles and consequently a plurality of flames are burning in the interior of the heating device.
Dependencies are inferred from the claim text.