Refractory product, a batch for producing the product, a method for the production of the product and a use of the product

Patent metadata

Field	Value
Publication number	US-11905218-B2
Application number	US-201917257849-A
Country	US
Kind code	B2
Filing date	May 29, 2019
Priority date	Aug 21, 2018
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

The invention relates to a refractory product, a batch composition for producing said product, a method for producing the product and the use of the refractory product.

First claim

The invention claimed is:

1. A refractory product comprising the following features:
1.1 the product has a chemical composition according to which the following oxides are present in the following proportions:
1.1.1 MgO: at least 92% by mass;
1.1.2 Al 2 O 3 : 1.5 to 7% by mass;
1.1.3 Fe 2 O 3 : less than 3% by mass;
1.1.4 CaO+SiO 2 : 1 to 3% by mass;

1.2. the product comprises coated grains having the following features:
1.2.1 the coated grains have a grain size of at least 2 mm;
1.2.2 the coated grains consist of magnesia, the surface of which has a coating of magnesia spinel at least in sections; and
1.2.3 the coating of magnesia spinel having a thickness in the range from 10 to 500 μm.

2. The product according to claim 1 , having a chemical composition with a content of MgO in the range from 92 to 96% by mass.

3. The product according to claim 1 , having a chemical composition with a content of Al 2 O 3 in the range from 2 to 3.5% by mass.

4. The product according to claim 1 , having a chemical composition with a content of Fe 2 O 3 of less than 1% by mass.

5. The product according to claim 1 , having a dynamic modulus of elasticity of less than 40 GPa.

6. The product according to claim 1 , having a temperature T 0.5 for refractoriness under load above 1,700° C.

7. The product according to claim 1 , the coated grains having a grain size in the range from 3 to 5 mm.

8. The product according to claim 1 , comprising the coated grains in a proportion in the range from 5 and 24% by mass.

9. The product according to claim 1 , comprising the coated grains in a proportion in the range from 5 to 24% by mass and further comprising magnesia in a proportion in the range from 76 to 95% by mass.

10. The product according to claim 1 in the form of a shaped fired refractory ceramic product.

11. A refractory product comprising the following features:
the refractory product has a chemical composition according to which the following oxides are present in the following proportions:
MgO: at least 92% by mass;
Al 2 O 3 : 1.5 to 7% by mass;
Fe 2 O 3 : less than 3% by mass;
CaO+SiO 2 : 1 to 3% by mass;
the refractory product comprises coated grains having the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of magnesia spinel at least in sections; and
the coating of magnesia spinel having a thickness in the range from 10 to 500 μm, wherein the refractory product is produced based upon a batch comprising the following features:
a first raw material component, consisting of grains of magnesia;
a second raw material component, consisting of batch coated grains, comprising the following features:
the batch coated grains have a grain size of at least 2 mm;
the batch coated grains consist of magnesia, the surface of which has a coating of alumina at least in sections.

12. The refractory according to claim 11 , wherein the batch coated grains have a grain size in the range from 3 to 5 mm.

13. A method for the production of a product comprising the following steps:
providing a batch, where the batch is for producing a refractory product, the batch comprising the following components:
a first raw material component, consisting of grains of magnesia;
a second raw material component, consisting of coated grains, comprising the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of alumina at least in sections;

shaping the batch into a shaped unfired refractory product;
firing the shaped unfired refractory product into a shaped fired refractory ceramic product, the shaped fired refractory product comprises the following features:
the shaped fired refractory ceramic product has a chemical composition according to which the following oxides are present in the following proportions:
MgO: at least 92% by mass;
Al 2 O 3 : 1.5 to 7% by mass;
Fe 2 O 3 : less than 3% by mass;
CaO+SiO 2 : 1 to 3% by mass;

the shaped fired refractory ceramic product comprises the coated grains having the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of magnesia spinel at least in sections; and
the coating of magnesia spinel having a thickness in the range from 10 to 500 μm.

14. A method comprising:
using a refractory product for lining of cement rotary kilns, where the refractory product comprises the following features:
the refractory product has a chemical composition according to which the following oxides are present in the following proportions:
MgO: at least 92% by mass;
Al 2 O 3 : 1.5 to 7% by mass;
Fe 2 O 3 : less than 3% by mass;
CaO+SiO 2 : 1 to 3% by mass;

the refractory product comprises coated grains having the following features:
the coated grains have a grain size of at least 2 mm;
the coated grains consist of magnesia, the surface of which has a coating of magnesia spinel at least in sections; and
the coating of magnesia spinel having a thickness in the range from 10 to 500 μm.

Assignees

• Refractory Intellectual Property Gmbh & Co Kg

Inventors

• Lynker Andreas
• Telser Heinz
• Nievoll Josef
• Geith Martin

Classifications

• C04B35/0435 Primary

  containing refractory metal compounds other than chromium oxide or chrome ore · CPC title

• C04B35/62813

  Alumina or aluminates · CPC title

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• F27B7/28

  Arrangements of linings · CPC title

• F27D1/0006

  Linings or walls formed from bricks or layers with a particular composition or specific characteristics · CPC title