Refractory product, use of zirconium dioxide, zirconium dioxide, method for manufacturing a refractory product and a refractory product manufactured therewith

Patent metadata

Field	Value
Publication number	US-10000418-B2
Application number	US-201515320928-A
Country	US
Kind code	B2
Filing date	May 28, 2015
Priority date	Jul 14, 2014
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

The invention relates to a refractory product comprising zirconium dioxide, a use of zirconium dioxide, a zirconium dioxide, a method for manufacturing a refractory product and a refractory product manufactured by means of said method. The zirconium dioxide is in cubic form and is metastable at room temperature. The zirconium dioxide has a content of calcium, magnesium and yttrium of less than 1% by weight.

First claim

The invention claimed is:

1. A refractory product comprising a mineral phase in the form of zirconium dioxide in the cubic variant thereof that is metastable at room temperature, having a content of calcium, magnesium and yttrium less than 1% by weight, wherein the zirconium dioxide comprises monocrystallites with a grain size in the range from 30 to 1,000 μm and wherein the quantity of oxides in the zirconium dioxide other than ZrO 2 or HfO 2 is less than 1.5% by weight.

2. The product according to claim 1 , in the shape of a wearing part for continuous steel casting.

3. The product according to claim 1 , in the shape of a slide plate, a monobloc stopper, a nozzle, an immersion pipe or a submerged nozzle.

4. The product according to claim 1 , in which the zirconium dioxide is present in a carbon matrix.

5. The product according to claim 1 , in which the zirconium dioxide was obtained by firing zirconium dioxide that was partly or fully stabilised with stabilising additives in a reducing atmosphere and in the presence of a gas-phase reagent for the stabilising additives, followed by cooling.

6. The product according to claim 5 , with stabilising additives in the form of at least one of the following substances: calcium oxide, magnesium oxide, yttrium oxide, or rare earth oxides.

7. The product according to claim 5 , in which the reducing atmosphere has a partial oxygen pressure below 10-6 Pa.

8. The product according to claim 5 , with a gas-phase reagent in the form of at least one of the following gas-phase substances: silicon, aluminium or carbon monoxide.

9. The product according to claim 5 , in which the firing is carried out at temperatures in the range from 1,173 to 2,690° C.

10. A zirconium dioxide in the form of a mineral phase that is metastable in the cubic variant thereof at room temperature, with a content of less than 1% by weight calcium, magnesium and yttrium, wherein the zirconium dioxide comprises monocrystallites with a grain size in the range from 30 to 1,000 μm and wherein the quantity of oxides in the zirconium dioxide other than ZrO 2 or HfO 2 is less than 1.5% by weight.

11. A method for manufacturing a refractory product comprising the following steps:
providing a mineral phase that is metastable at room temperature in the form of zirconium dioxide in the cubic variant containing a quantity of less than 1% by weight calcium, magnesium and yttrium, wherein the zirconium dioxide comprises monocrystallites with a grain size in the range from 30 to 1,000 μm and wherein the quantity of oxides in the zirconium dioxide other than ZrO 2 or HfO 2 is less than 1.5% by weight;
combining the zirconium dioxide with additional refractory raw materials;
pressing a moulded body made from the zirconium dioxide and the additional refractory raw materials;
firing the moulded body to produce a refractory product.

12. A refractory product manufactured using a method, the method comprising:
providing a mineral phase that is metastable at room temperature in the form of zirconium dioxide in the cubic variant containing a quantity of less than 1% by weight calcium, magnesium and yttrium, wherein the zirconium dioxide comprises monocrystallites with a grain size in the range from 30 to 1,000 μm and wherein the quantity of oxides in the zirconium dioxide other than ZrO 2 or HfO 2 is less than 1.5% by weight;
combining the zirconium dioxide with additional refractory raw materials;
pressing a moulded body made from the zirconium dioxide and the additional refractory raw materials; and
firing the moulded body to produce a refractory product.

Assignees

• Refractory Intellectual Property Gmbh & Co Kg

Inventors

• Bauer Christoph
• Freiberger Norbert

Classifications

• C04B2235/9676

  against molten metals such as steel or aluminium · CPC title

• C04B2235/9669

  Resistance against chemicals, e.g. against molten glass or molten salts · CPC title

• C04B2235/80

  Phases present in the sintered or melt-cast ceramic products other than the main phase · CPC title

• C04B2235/786

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

• C04B2235/762

  Cubic symmetry, e.g. beta-SiC · CPC title