Product having a high alumina content

Patent metadata

Field	Value
Publication number	US-10167233-B2
Application number	US-201414907918-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 26, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A sintered refractory product having the form of a block and consisting of a granulate formed by all the grains having a size larger than 100 μm, referred to as “coarse grains”, and a matrix binding the coarse grains and consisting of the grains having a size smaller than or equal to 100 μm, the granulate representing between 45% and 90% by mass of the product, the product having a composition such that, in a mass percentage based on the oxides: Al2O3>80%, SiO2<15%, Na2O<0.15%, Fe2O3<0.05%, CaO<0.1%, the other oxides forming the remainder up to 100%, and the Na2O content in the matrix being greater than 0.010%, in a mass percentage based on the mass of the product.

First claim

The invention claimed is:

1. A sintered refractory product having the shape of a block and consisting of:
grains having a size of greater than 100 μm, referred to as “coarse grains”, the coarse grains forming an aggregate, and
a matrix bonding said coarse grains and consisting of grains having a size of less than or equal to 100 μm,

the aggregate representing between 45% and 90% by weight of the product,
said product having a composition such that, as a weight percentage on the basis of the oxides:
Al 2 O 3 >80%,
SiO 2 <15%,
Na 2 O<0.15%
Fe 2 O 3 <0.05%,
CaO<0.1%,
the other oxides constituting the balance to 100%,

the content of Na 2 O in the matrix being greater than 0.010%, as a weight percentage on the basis of the weight of the product, the product having crystalline phases.

2. The product as claimed claim 1 , wherein:
Na 2 O+K 2 O<0.20%.

3. The product as claimed in claim 1 , wherein:
Al 2 O 3 >85% and/or
3%<SiO 2 <10% and/or
Na 2 O+K 2 O<0.15% and/or
Fe 2 O 3 <0.03% and/or
CaO<0.05% and/or
ZrO 2 <5% and/or
TiO 2 <5%.

4. The product as claimed claim 1 , wherein:
Al 2 O 3 >90% and/or
SiO 2 >7% and/or
Na 2 O<0.12% and/or
ZrO 2 <1% and/or
TiO 2 <1%.

5. The product as claimed in claim 1 , wherein the content of Na 2 O in the aggregate is less than 0.070%, as a weight percentage on the basis of the weight of the aggregate.

6. The product as claimed in claim 1 , wherein a total amount of
alumina and of
mullite and/or spinel and/or mullite-zirconia is greater than 95%, as a weight percentage on the basis of the weight of the crystalline phases.

7. The product as claimed in claim 1 , wherein the amount of mullite is greater than 10% and less than 50%, as a weight percentage on the basis of the weight of the crystalline phases.

8. The product as claimed in claim 1 , having an open porosity of greater than 10% and less than 30% by volume.

9. The product as claimed in claim 1 , having an open porosity of less than 20% by volume.

10. The product as claimed in claim 1 , having a pore size distribution, measured using a mercury porosimeter, such that:
P 50 is greater than 1 μm and less than 20 μm, and/or
P 80 is greater than 10 μm and less than 50 μm, and/or
P 90 is greater than 30 μm and less than 70 μm.

11. The product as claimed in claim 1 , wherein more than 90% by weight of the aggregate consists of coarse mullite grains, coarse alumina grains, coarse spinel grains, coarse mullite-zirconia grains, or any combination thereof.

12. The product as claimed in claim 1 , wherein more than 90% by weight of the matrix consists of alumina.

13. The product as claimed in claim 1 , wherein the grains of the matrix having a size greater than 10 μm represent more than 10% and less than 30% of the weight of the product and/or the grains of the matrix having a size less than or equal to 10 μm represent more than 10% and less than 30% of the weight of the product.

14. A device selected from the group formed by a gas turbine, a chemical reactor, a firing support and a glass furnace superstructure, said device comprising one wall at least partly formed by a product according to claim 1 .

15. The device as claimed in claim 14 , said chemical reactor being a secondary reforming reactor for the manufacture of ammonia or methane, and the firing support being a firing support for ceramic parts.

Assignees

• Saint Gobain Ct Recherches

Inventors

• San-Miguel Laurie
• Rodrigues Fabiano
• His Christian
• Champion Thibault

Classifications

• B01J19/02

  Apparatus characterised by being constructed of material selected for its chemically-resistant properties · CPC title

• C04B2235/3463

  Alumino-silicates other than clay, e.g. mullite · CPC title

• F23R3/002

  Wall structures (F23R3/02 and F23R3/007 take precedence) · CPC title

• C04B2235/77

  Density · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title