Method of preparing cerium boride powder

Patent metadata

Field	Value
Publication number	US-10793476-B2
Application number	US-201816198878-A
Country	US
Kind code	B2
Filing date	Nov 23, 2018
Priority date	Aug 21, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A method of preparing cerium boride powder, according to the present invention, includes a first step for generating mixed powder by mixing at least one selected from among cerium chloride (CeCl 3 ) powder and cerium oxide (CeO 2 ) powder, at least one selected from among magnesium hydride (MgH 2 ) powder and magnesium (Mg) powder, and boron oxide (B 2 O 3 ) powder, a second step for generating composite powder including cerium boride (Ce x B y ) and at least one selected from among magnesium oxide (MgO) and magnesium chloride (MgCl 2 ), by causing reaction in the mixed powder at room temperature based on a ball milling process, and a third step for selectively depositing cerium boride powder by dispersing the composite powder in a solution.

First claim

What is claimed is:

1. A method of preparing cerium boride powder, the method comprising:
a first step, for generating a mixed powder, by mixing magnesium hydride (MgH 2 ) powder, boron oxide (B 2 O 3 ) powder, and at least one selected from the group consisting of cerium (III) chloride (CeCl 3 ) powder and cerium (IV) oxide (CeO 2 ) powder;
a second step, for generating a composite powder comprising cerium boride (CeB 6 ) and at least one selected from the group consisting of magnesium oxide (MgO) and magnesium chloride (MgCl 2 ), of reacting the mixed powder at room temperature in a ball milling process; and
a third step, for selectively depositing cerium boride powder, of dispersing the composite powder in a solution.

2. The method of claim 1 , wherein the first step comprises generating the mixed powder by mixing the CeCl 3 powder, the MgH 2 powder, and the B 2 O 3 powder, and
wherein the third step comprises selectively dissolving MgCl 2 and MgO and selectively depositing the cerium boride powder by dispersing the composite powder in an acidic solution.

3. The method of claim 1 , wherein the first step comprises generating the mixed powder by mixing the CeCl 3 powder, the MgH 2 powder, and the B 2 O 3 powder, and
wherein the third step comprises selectively dissolving MgCl 2 and obtaining deposited powder by dispersing the composite powder in a solution and removing MgO and obtaining the cerium boride powder by adding acid to the deposited powder.

4. The method of claim 1 , wherein the first step comprises generating the mixed powder by mixing the CeO 2 powder, the MgH 2 powder, and the B 2 O 3 powder, and
wherein the third step comprises selectively dissolving MgO and selectively depositing the cerium boride powder by dispersing the composite powder in an acidic solution.

5. The method of claim 1 , wherein, in the second step, the ball milling process comprises a process of putting balls and the mixed powder in a reaction vessel, filling air, argon (Ar), helium (He), nitrogen (N 2 ), or hydrogen (H 2 ) gas in the reaction vessel, and then performing ball milling.

6. The method of claim 5 , wherein the ball milling process comprises a high-energy ball milling process selected from a process consisting of a shaker mill process, a vibratory mill process, a planetary mill process, and an attritor mill process.

7. The method of claim 1 , wherein, in the third step, the cerium boride powder has a particle size equal to or less than 5 μm and a crystal grain size of 20 nm.

8. The method of claim 1 , wherein the third step is performed at room temperature.

9. The method of claim 1 , wherein the cerium boride powder prepared using the mixed powder comprising the MgH 2 powder has a crystal grain size less than a crystal grain size of a cerium boride powder prepared using a mixed powder comprising Mg powder.

Assignees

• Korea Inst Sci & Tech

Inventors

• Shim Jae Hyeok
• Ha Tae Jun
• Suh Jin Yoo

Classifications

• C04B35/62615

  High energy or reactive ball milling · CPC title

• C04B2235/549

  the particle size being expressed by crystallite size or primary particle size · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B2235/612

  Machining · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title