Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for preparing rare earth metal hexaboride by aluminothermic reduction

A technology of rare earth metal and hexaboride, which is applied in the field of preparation of rare earth metal hexaboride, can solve the problems of high cost of rare earth metal boride, difficulty in producing products in large quantities, and restrictions on large-scale application of materials, and achieve high temperature reaction Safe and controllable process, low raw material cost, and low thermal effect of thermite reaction

Active Publication Date: 2022-07-05
UNIV OF SCI & TECH BEIJING
View PDF9 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since these two raw materials are not easy to obtain, the acquisition cost of rare earth metal borides is extremely high
In addition, the process of direct elemental synthesis is accompanied by strong heat release, which makes it difficult to produce products in large quantities at one time.
These two points limit the large-scale application of this material

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for preparing rare earth metal hexaboride by aluminothermic reduction

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] (1) The purity of 99.99wt.% lanthanum oxide (La 2 O 3 ), boron carbide with a boron content of 74.4 wt.% (B 4 C) and pure metal aluminum powder (Al) were weighed and mixed uniformly according to the molar ratio of 1:3:9.

[0035] (2) Heat the mixed material in (1) to 1400°C in a high-temperature furnace with argon, and keep it for 6 hours. After the high-temperature furnace is cooled to 20-50°C, take out the material.

[0036] (3) The reduction product obtained in (2) was crushed to -50 mesh, and the product was placed in a 30 wt.% sodium hydroxide solution and washed with alkali at 90° C. for 8 hours. After the alkali washing is completed, the leaching slurry is filtered, the filtered solid powder is washed, and the washed powder is dried. Finally, pure lanthanum boride (LaB 6 )powder.

Embodiment 2

[0038] (1) Cerium oxide (CeO) with a purity of 99.5 wt.% 2 ), boron carbide with a boron content of 85.4 wt.% (B 13 C 2 ) and pure metal aluminum particles (Al) were weighed and mixed uniformly in a molar ratio of 1:0.46:12.

[0039] (2) Heat the mixed material in (1) to 1500°C in a high-temperature furnace with argon, and keep it for 4 hours. After the high-temperature furnace is cooled to 20-50°C, the material is taken out.

[0040] (3) The reduction product obtained in (2) was crushed to -50 mesh, and the product was placed in a 25 wt.% sodium hydroxide solution, and washed with alkali at 65° C. for 12 hours. After the alkali washing is completed, the leaching slurry is filtered, the filtered solid powder is washed, and the washed powder is dried. Finally, pure cerium boride (CeB 6 )powder.

Embodiment 3

[0042](1) Praseodymium oxide (Pr 6 O 11 ), boron carbide with a boron content of 77.6 wt.% (B 4 C) and pure metal aluminum powder (Al) were weighed and mixed uniformly according to the molar ratio of 1:9:30.

[0043] (2) Heat the mixed material in (1) to 1500°C in a high-temperature furnace with argon, and keep it for 4 hours. After the high-temperature furnace is cooled to 20-50°C, the material is taken out.

[0044] (3) The reduction product obtained in (2) was crushed to -50 mesh, and the product was placed in a 30 wt.% sodium hydroxide solution and washed with alkali at 90° C. for 8 hours. After the alkali washing is completed, the leaching slurry is filtered, the filtered solid powder is washed, and the washed powder is dried. Finally, pure praseodymium boride (PrB 6 )powder.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method for preparing rare earth metal hexaboride by aluminothermic reduction relates to the technical field of preparation of rare earth metal hexaboride, comprising: step 1: uniformly mixing rare earth oxide, boron carbide and metal aluminum to obtain mixed raw materials; step 2: in The mixed raw materials are heated in an inert atmosphere to cause a high-temperature reduction reaction; step 3: the product obtained after the high-temperature reduction reaction is completed is sequentially cooled, crushed and finely ground to obtain a reduction product powder; step 4: the The reduction product powder is subjected to alkali washing, filtration, rinsing and drying in sequence to obtain rare earth metal hexaboride. The invention adopts rare earth oxide, boron carbide and metal aluminum as raw materials to prepare rare earth metal hexaboride, solves the problem of strong exothermic heat in the traditional method, greatly reduces the reaction heat effect of the high temperature process, and comprehensively considers the economical efficiency of the method and the method. Implementability.

Description

technical field [0001] The invention relates to the technical field of preparation of rare earth metal hexaborides, in particular to a method for preparing rare earth metal hexaborides by aluminothermic reduction. Background technique [0002] Rare earth metal borides have become the most widely used high-end electron emission cathode materials due to their excellent electron emission properties. such as LaB 6 and CeB 6 It has been widely used in high-end equipment such as electron microscopes, electron beam etching systems and X-ray sources. In addition, the melting point of rare earth metal borides is often close to 3000 ° C, which is a ceramic material that can be used under extreme conditions. At the same time, rare earth metal borides often have special electromagnetic properties. However, the method of rare earth metal boride that can be applied at present is generally an elemental synthesis method, which directly uses rare earth metal and amorphous boron powder fo...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C01F17/20C01F17/10
CPCC01F17/20C01F17/10Y02P10/20
Inventor 张国华汪宇
Owner UNIV OF SCI & TECH BEIJING