Low alkali, non-crystalline, vitreous silica fillers

• US 20090318279A1
• Filed: 08/26/2009
• Published: 12/24/2009
• Est. Priority Date: 03/02/2001
• Status: Active Grant

• Current Assignee: Albacem, LLC
• Original Assignee: Albacem, LLC
• Inventors: Cornelius, Bruce J., Hemmings, Raymond T., Graves, Philip L., Nelson, Robert D.
• Granted Patent: US 7,811,377 B2
• Time in Patent Office: Days
• US Class Current: 501/53
• CPC Class Codes: C03C 12/00 Powdered glass C03C8/02 takes precedence; Bead compositions
• CPC Class Codes: C03C 13/00 Fibre or filament compositions manufacture of fibres or filaments C03B37/00
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C04B 14/22 Glass ; Devitrified glass
• CPC Class Codes: C04B 20/026 Comminuting, e.g. by grinding or breaking; Defibrillating fibres other than asbestos
• CPC Class Codes: C04B 2111/802 White cement
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 7/02 Portland cement
• CPC Class Codes: C04B 7/12 Natural pozzuolanas; Natural pozzuolana cements; Artificial pozzuolanas or artificial pozzuolana cements other than those obtained from waste or combustion residues, e.g. burned clay; Treating inorganic materials to improve their pozzuolanic characteristics cements containing slag C04B7/14
• CPC Class Codes: C04B 7/13 Mixtures thereof with inorganic cementitious materials, e.g. Portland cements

Abstract

A substantially white powder for use as a filler and/or extender derived from by-products of manufacturing vitreous low alkali, low iron glass fibers, and a method for producing the powder. The filler has very low alkalinity and by virtue of its being essentially free of crystalline silica is non-hazardous to health and therefore safe for consumer-based and industrial-based uses.

Claims

1. A white high brightness powder for use in filler and extender applications comprising a finely ground vitreous calcium aumino-silicate (CaO—

Al₂O₃—

SiO₂) powder derived from previously discarded glass fibers having low alkali and low iron content and low iron content and low levels of discolorants;

said powder having an alkali content by weight of not more than 2% as (Na₂O+K₂O), an iron content by weight of not more than 0.8% as Fe₂O₃ and being substantially white in color with a reflectance value of at least 80 as measured by a Technibrite TB-1C calorimeter according to the ISO 2467, 2471 method;

at least 95% by weight of the powder comprising particles of less than 45 microns E.S.D. and said particles having a blocky, relatively equi-dimensional particle shape wherein the average aspect ratio of the particles in less than 2;

1, and with substantially no residual high aspect ratio fibers.

2. A composition in accordance with claim 1, wherein the said powder has a P.S.D. such that at least 95% by weight of the particles are of less than 25 microns E.S.D.

3. A composition in accordance with claim 1, wherein the said powder has a P.S.D. such that at least 95% by weight of the particles are of less than 10 microns E.S.D.

4. A composition in accordance with claim 1, wherein the said powder has a P.S.D. such that at least 95% by weight of the particles are of less than 5 microns E.S.D.

5. A composition in accordance with claim 1, wherein the said powder has a P.S.D. such that at least 95% by weight of the particles are of less than 3 microns E.S.D.