Method for preparing small-particle-size aluminium oxide powder

A technology of alumina powder and fine particle size, which is applied in the field of powder preparation and particle size control, can solve the problems of difficult to obtain alumina powder and alumina growth, and achieve lower calcination temperature, high powder uniformity, and particle size shape-controllable effect

Active Publication Date: 2015-04-22
贵州天合国润高新材料科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

When calcined at high temperature, alumina tends to grow and it is difficult to obtain nano-scale alumina powder

Method used

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  • Method for preparing small-particle-size aluminium oxide powder
  • Method for preparing small-particle-size aluminium oxide powder
  • Method for preparing small-particle-size aluminium oxide powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Example 1: Preparation of fine-grained alumina powder with aluminum hydroxide as raw material

[0023] Using industrial aluminum hydroxide powder as raw material, add 0.5wt.% seed crystal (20nm α-TiNC), 0.1wt.% dispersant (benzoic acid), 0.015wt.% grain growth inhibitor ( Mg(OH)Cl), mixed uniformly by means of stirring or ball milling, and then dried at 50° C. for 8 hours to obtain a mixture. Add 1wt.% dextrin or polyvinyl alcohol to the dried mixture, and shape it under a pressure of 600 MPa to obtain a primary green body; the primary green body is calcined at a high temperature at 1160° C. for 8 hours. The concentration of hydrogen fluoride in the primary calcination atmosphere is 0.1%, the concentration of ammonia is 1.1%, the concentration of aluminum fluoride is 1%, the concentration of hydrogen is 4%, the concentration of nitrogen is 6%, and the balance is air. After the primary calcination, the primary calcined green body is obtained; the primary calcined green ...

Embodiment 2

[0024] Example 2: with γ-Al 2 o 3 Preparation of fine particle size alumina powder as raw material

[0025] γ-Al 2 o 3 As raw material, add 1wt.% seed crystal (15nm V 2o 5 ), 0.6wt.% dispersant (phenyl acetate), 1.2wt.% grain growth inhibitor (MgO) and 0.4wt.% gas phase source (ammonium hypochlorite), after mixing evenly by means of stirring or ball milling Dry at 80° C. for 3 hours to obtain a mixture. Add 2.6wt.% dextrin or polyvinyl alcohol to the dried mixture and shape it under a pressure of 700MPa to obtain a primary green body; the primary green body is calcined at a high temperature at 1300°C for 3 hours . The concentration of hydrogen chloride in the primary calcination atmosphere is 1.0%, the concentration of ammonia is 1.5%, the concentration of aluminum fluoride is 2%, the concentration of hydrogen is 5%, the concentration of nitrogen is 10%, and the balance is air. After the primary calcination, the primary calcined green body is obtained; the primary calc...

Embodiment 3

[0026] Embodiment 3: with aluminum hydroxide and NH 4 F is used as raw material to prepare fine-grained alumina powder

[0027] θ-Al 2 o 3 powder as raw material, add 0.8wt.% seed crystal (15nm α-TiO 2 ), 1.0wt.% dispersant (methyl benzoate), 0.06wt.% grain growth inhibitor (MgCl 2 ), 0.5wt.% gas source (NH 4 Cl), mixed uniformly by means of stirring or ball milling, and then dried at 60° C. for 4 hours to obtain a mixture. Add 3wt.% dextrin or polyvinyl alcohol to the dried mixture, and shape it under a pressure of 580 MPa to obtain a primary green body; the primary green body is calcined at a high temperature at 1200° C. for 6 hours. The concentration of hydrogen bromide in the primary calcination atmosphere is 0.5%, the concentration of ammonia is 1.2%, the concentration of aluminum fluoride is 2%, the concentration of hydrogen is 3%, the concentration of nitrogen is 8%, and the balance is air. After the primary calcination, the primary calcined green body is obtained...

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Abstract

The invention provides a method for preparing small-particle-size aluminium oxide powder, and belongs to the technical field of powder preparation and particle size control. The process flow is as follows: by taking industrial aluminium hydroxide or transition-phase aluminium oxide powder as a raw material, adding a seed crystal, a dispersant, a particle size control component and a gas-phase source in the raw material powder, and uniformly mixing the raw material powder and then pressing to form a blank; calcining the blank in an atmosphere containing hydrogen halide and the particle size control component at a high temperature, breaking the calcined blank into powder, secondarily forming and then calcining in an atmosphere containing high-concentration hydrogen halide at a low temperature to obtain the submicron-scale or nanoscale aluminium oxide powder with a particle size of less than 0.14mu m and an alpha-Al2O3 content of 100%. The method provided by the invention is low in reaction temperature, short in reaction time and simple in process; the obtained aluminium oxide powder is good in dispersibility.

Description

technical field [0001] The invention belongs to the technical field of powder preparation and particle size control, and particularly provides a method for preparing alumina powder with fine particle size. Background technique [0002] Fine particle size alumina powder (submicron and nanoscale alumina powder) not only has the characteristics of high melting point, high hardness, high strength and corrosion resistance, but also has significant surface effect, small size effect, quantum effect, and macroscopic quantum tunneling effect. As well as high sintering activity, it exhibits a series of excellent electrical, magnetic, optical, mechanical and chemical macroscopic properties, and has broad application prospects in abrasives, cutting tools, composite materials, microelectronics, chemicals, aerospace industry, fine ceramics and other fields. The preparation of fine particle size alumina powder mainly includes solid phase synthesis method, chemical pyrolysis method, amorpho...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/02C01F7/44
Inventor 章林
Owner 贵州天合国润高新材料科技有限公司
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