Refractory object, glass overflow forming block, and process of forming and using the refractory object

Patent metadata

Field	Value
Publication number	US-9796630-B2
Application number	US-201514873427-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Mar 30, 2011
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A refractory object can include at least 10 wt % Al 2 O 3 . Further, the refractory object may contain less than approximately 6 wt % SiO 2 or may include a dopant that includes an oxide of Ti, Mg, Ta, Nb, or any combination thereof. In an embodiment, at least approximately 1% of the Al 2 O 3 in the refractory object can be provided as reactive Al 2 O 3 . In another embodiment, the refractory object may have a density of at least approximately 3.55 g/cc, a corrosion rate of no greater than approximately 2.69 mm/year, or any combination of the foregoing. In a particular embodiment, the refractory object can be used to form an Al—Si—Mg glass sheet. In an embodiment, the refractory object may be formed by a process using a compound of Ti, Mg, Ta, Nb, or any combination thereof.

First claim

What is claimed is:

1. A refractory object used in forming a glass object, the refractory object comprising:
at least 95 wt % Al 2 O 3 ;
less than 0.009 wt % of SiO 2 ;
less than 1.5 wt % TiO 2 ;
a dopant including at least 0.5 wt % Nb 2 O 5 ;
a porosity no greater than 9.0 vol %; and
a corrosion rate no greater than 2.69 mm/year at an operating temperature of 1150° C. and a molten glass velocity of 27 cm/min.

2. The refractory object according to claim 1 , wherein the glass object is in a form of a glass sheet.

3. The refractory object according to claim 2 , wherein the glass sheet has a thickness of at least 20 μm.

4. The refractory object according to claim 2 , wherein the glass sheet has a thickness no greater than 5 mm.

5. The refractory object according to claim 4 , wherein the glass sheet has a width of at least 0.2 m.

6. The refractory object according to claim 2 , wherein the glass object includes an alkali glass.

7. The refractory object according to claim 1 , wherein the refractory object has a density of at least 3.55 g/cc.

8. The refractory object of claim 1 , wherein a content of the dopant is no greater than 5 wt %.

9. The refractory object of claim 1 , wherein at least 1% of the Al 2 O 3 in the refractory object is provided as reactive Al 2 O 3 .

10. The refractory object of claim 1 , wherein no greater than 99% of the Al 2 O 3 in the refractory object is provided as reactive Al 2 O 3 .

11. The refractory object of claim 1 , wherein the corrosion rate is no greater than 1.6 mm/year at an operating temperature of 1150° C. and a molten glass velocity of 27 cm/min.

12. The refractory object of claim 1 , wherein the porosity is at least 0.05 vol %.

13. The refractory object of claim 1 , wherein the refractory object has a porosity no greater than 9.0 vol %.

14. The refractory object of claim 1 , wherein the refractory object has a length of at least 0.5 m.

15. A refractory object used in forming a glass object, the refractory object comprising:
at least 95 wt % Al 2 O 3 ;
less than 0.05 wt % of SiO 2 ;
less than 1.5 wt % TiO 2 ;
at least 0.2 wt % of an oxide of Ta;
a density of no greater than 3.9 g/cc.

16. The refractory object of claim 15 , wherein the refractory object has a porosity no greater than 9.0 vol %.

17. The refractory object of claim 15 , wherein at least 1% of the Al 2 O 3 in the refractory object is provided as reactive Al 2 O 3 .

18. The refractory object of claim 15 , wherein no greater than 99% of the Al 2 O 3 in the refractory object is provided as reactive Al 2 O 3 .

Assignees

• Saint-Gobain Ceram & Plastics Inc

Inventors

• Citti Olivier
• Kazmierczak Andrea L

Classifications

• C04B2235/3232

  Titanium oxides or titanates, e.g. rutile or anatase · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C03B17/064

  by the overflow downdraw fusion process; Isopipes therefor · CPC title

• C04B35/62665

  Flame, plasma or melting treatment · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title