Method for synthesis of boron suboxide

Patent metadata

Field	Value
Publication number	US-9908782-B2
Application number	US-201313767358-A
Country	US
Kind code	B2
Filing date	Feb 14, 2013
Priority date	Feb 14, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Methods of preparing boron suboxide are provided herein. In some embodiments, a method for preparing boron suboxide may include loading elemental boron powder into a furnace; purging the furnace by flowing a first gas comprising one of nitrogen or an inert gas into the furnace; heating the boron powder in a reactive atmosphere comprising a mixture of argon and a non-reducing oxygen-containing gas to convert elemental boron powder into boron suboxide powder, wherein the amount of oxygen in the reactive atmosphere is no greater than about 1%.

First claim

The invention claimed is:

1. A method of preparing a boron suboxide powder, comprising:
loading elemental boron powder into a furnace;
purging the furnace by flowing a gas selected from the group consisting of nitrogen, other inert gases and mixtures thereof into the furnace;
flowing a mixture of water vapor and argon, nitrogen, other inert gas, or a mixture thereof that is produced by bubbling the argon, nitrogen, other inert gas, or a mixture thereof through water to provide a reactive atmosphere;
heating the elemental boron powder in the reactive atmosphere comprising a mixture of water vapor and argon, nitrogen, other inert gas, or a mixture thereof to convert the elemental boron powder into boron suboxide powder; and
removing the boron suboxide powder from the furnace
wherein oxygen that is used to convert the elemental boron powder into boron suboxide powder is supplied from oxygen that is in the mixture of water vapor and argon, nitrogen, other inert gas, or a mixture thereof that is the product of bubbling the argon, nitrogen, other inert gas, or a mixture thereof gas through water.

2. The method of claim 1 , wherein the purity of the elemental boron powder is at least 92%.

3. The method of claim 1 , wherein the purity of the elemental boron powder is at least 95%.

4. The method of claim 1 , wherein the purity of the elemental boron powder is in the range of from about 92% to about 95%.

5. The method of claim 1 , wherein the elemental boron powder comprises at least one of crystalline boron and amorphous boron.

6. The method of claim 1 , wherein purging the furnace by flowing nitrogen further comprises purging the nitrogen from the furnace by flowing an inert gas into the furnace.

7. The method of claim 1 , further comprising:
washing the suboxide boron powder in deionized water and filtering the boron suboxide powder to remove at least one of a boron oxide (B 2 O 3 ) or a boron hydroxide formed on the surface of the boron suboxide powder.

8. The method of claim 1 , wherein heating the elemental boron powder further comprises heating the furnace to a temperature of from about 1200° C. to about 1500° C. for up to about 5 hours.

9. The method of claim 1 , wherein the particle size of the boron suboxide powder removed from the furnace is equal to the particle size of the elemental boron powder loaded into the furnace.

10. The method of claim 1 , further comprising sintering the removed boron suboxide powder without milling the boron suboxide powder.

11. The method of claim 1 , further comprising heating the elemental boron powder at a pressure within the furnace of about atmospheric pressure.

12. The method of claim 1 , wherein amount of oxygen in the reactive atmosphere converts about 50% to about 80% of the elemental boron powder into boron suboxide powder and about 50% to about 20% of the elemental boron powder into at least one of boron trioxide or boric acid.

13. The method of claim 1 , further comprising agitating the elemental boron powder within the furnace.

14. A method of preparing a boron suboxide powder, comprising:
loading elemental boron powder into a furnace;
purging the furnace by flowing nitrogen, an inert gas, or a mixture thereof into the furnace;
flowing a mixture of argon and water vapor that is produced by bubbling argon through water;
heating the elemental boron powder to a temperature of from about 1200° C. to about 1500° C. and at a pressure of about atmospheric pressure in an atmosphere comprising a mixture of argon and water vapor to convert elemental boron powder into boron suboxide powder;
agitating the elemental boron powder within the furnace; and
removing the boron suboxide powder from the furnace
wherein oxygen that is used to convert the elemental boron powder into boron suboxide powder is supplied from oxygen that is in the argon and water vapor mixture that is the product of bubbling the inert gas through water.

15. The method of claim 14 , further comprising washing the boron suboxide powder in deionized water and filtering the boron suboxide powder to remove at least one of a boron oxide (B 2 O 3 ) or a boron hydroxide formed on the surface of the boron suboxide powder.

16. A method of preparing a boron suboxide powder, comprising the steps of:
loading elemental boron powder into a furnace;
purging the furnace by flowing a gas selected from the group consisting of nitrogen, other inert gases and mixtures thereof into the furnace;
flowing an argon and water vapor that is supplied by bubbling an argon gas through water to form an argon and water vapor mixture;
heating the elemental boron powder in the atmosphere comprising the argon and water vapor mixture;
converting the elemental boron powder into boron suboxide powder; and
removing the boron suboxide powder from the furnace;
wherein oxygen that is used to convert the elemental boron powder into boron suboxide powder is supplied from oxygen that is in the argon and water vapor mixture.

17. The method of claim 1 , wherein the reactive atmosphere comprises a mixture of argon and oxygen gas and the amount of oxygen in the reactive atmosphere is no greater than about 1%.

18. The method of claim 14 , wherein the reactive atmosphere comprises a mixture of argon and oxygen gas and the amount of oxygen in the reactive atmosphere is no greater than about 1%.

19. The method of claim 16 , wherein the reactive atmosphere comprises a mixture of argon and oxygen gas and the amount of oxygen in the reactive atmosphere is no greater than about 1%.

20. A method of preparing a boron suboxide powder, comprising:
loading elemental boron powder into a furnace;
purging the furnace by flowing a gas selected from the group consisting of nitrogen, other inert gases and mixtures thereof into the furnace;
flowing a mixture of nitrogen, an inert gas, or a mixture thereof and water vapor that is produced by bubbling nitrogen, an inert gas, or a mixture thereof through water to provide a reactive atmosphere;
heating the elemental boron powder in the reactive atmosphere comprising a mixture of an argon and water vapor to convert the elemental boron powder into boron suboxide powder; and
removing the boron suboxide powder from the furnace
wherein oxygen that is used to convert the elemental boron powder into boron suboxide powder is supplied from oxygen that is in the nitrogen, an inert gas, or a mixture thereof and water vapor mixture that is the product of bubbling the nitrogen, an inert gas, or a mixture thereof through water.

Assignees

• Us Army Res Lab
• Us Army

Inventors

• Pavlacka Robert J
• Gilde Gary A

Classifications

• C01B35/1027 Primary

  Oxides · CPC title