Method for preparing pseudo-boehmite and method for preparing microcrystalline fused alumina abrasive

A pseudo-boehmite and microcrystalline corundum technology, applied in chemical instruments and methods, alumina/aluminum hydroxide, other chemical processes, etc., can solve the problems of low purity, reduced product strength, poor quality controllability, etc. Achieve the effect of high purity and strength, improved compatibility, and convenient operation

Inactive Publication Date: 2012-12-05
SHANGHAI SHANGMO ABRASIVES & GRINDING TOOL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] 1. Boehmite or pseudo-boehmite is usually used as the precursor, and the relative cost is relatively high; and the boehmite or pseudo-boehmite products currently on the market have large particle size, poor uniformity, and low purity (mostly contain sodium ions, calcium ions, etc.), it is easy to cause the sintered microcrystalline corundum grain size to be large, and the impurity content is high, which directly leads to low strength of the final product and poor quality controllability (grain size)
[0008] 2. The seeding process has significant limitations
The introduced crystal seed itself has the same lattice structure as α-alumina, but is completely different from the precursor of α-alumina (boehmite or pseudo-boehmite), so it is difficult to mix and dissolve in the process of peptization and mixing. It is easy to cause uneven distribution and increase the difficulty of large-scale production; and the activity of this type of seed crystal material itself is low, and it is easy to form defects during the sintering process of the final product, reducing the product strength

Method used

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  • Method for preparing pseudo-boehmite and method for preparing microcrystalline fused alumina abrasive
  • Method for preparing pseudo-boehmite and method for preparing microcrystalline fused alumina abrasive
  • Method for preparing pseudo-boehmite and method for preparing microcrystalline fused alumina abrasive

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] 1. Preparation of pseudoboehmite

[0034] Add 250 grams of deionized water into a polytetrafluoroethylene reactor with a volume of 500 ml, and then add 25 grams of anhydrous aluminum trichloride while stirring. After the aluminum trichloride is completely dissolved, heat to 80°C while stirring, and then continue heating to keep the temperature constant. Then close the reaction kettle, slowly add 50 grams of ammonia water to the closed reaction kettle under stirring for hydrolysis (the hydrolysis is completed within 1 minute). After the hydrolysis is complete, the generated Al(OH) 3 The precipitate formed a suspension with stirring.

[0035] The resulting suspension was stirred and heated in a closed polytetrafluoroethylene reactor at 90°C for 3 hours to make the Al(OH) 3 It is completely hydrolyzed to pseudo-boehmite (Al 2 o 3 ·nH 2 O, where n=0.08~0.62).

[0036] Centrifuge the white reaction product while it is hot, then add 80°C deionized water to wash the so...

Embodiment 2

[0047] 1. Preparation of pseudoboehmite

[0048] Method is the same as embodiment 1, and difference is that the consumption of anhydrous aluminum trichloride is brought up to 50 grams, and the add-on of ammoniacal liquor is brought up to 100 grams.

[0049] 2. Preparation of Microcrystalline Corundum Abrasives

[0050] Method is with embodiment 1.

[0051] The crystal grain diameter of the obtained microcrystalline corundum abrasive is 100-300nm, and the particle density is 3.88g / cm 3 , the average hardness is 19.8Gpa, and the single particle strength is 40.8N.

Embodiment 3

[0053] 1. Preparation of pseudoboehmite

[0054] The method is the same as in Example 1, except that 70 grams of aluminum nitrate nonahydrate is used instead of 25 grams of anhydrous aluminum trichloride.

[0055] 2. Preparation of Microcrystalline Corundum Abrasives

[0056] Method is with embodiment 1.

[0057] The crystal grain diameter of the obtained microcrystalline corundum abrasive is 100-300nm, and the particle density is 3.87g / cm 3 , the average hardness is 20.3Gpa, and the single particle strength is 40.3N.

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Abstract

The invention discloses a method for preparing pseudo-boehmite. The method includes preparing water-soluble salt of aluminum into pseudo-boehmite by a hydrothermal method. The invention further discloses a method for preparing microcrystalline fused alumina abrasive. The method for preparing microcrystalline fused alumina abrasive includes by the sol-gel process, performing ball milling, drying, breaking and granulating, calcination and firing to the prepared pseudo-boehmite to prepare the microcrystalline fused alumina abrasive. The methods are convenient to implement, low in cost and suitable for large-scale production, and purity and particle strength of the prepared microcrystalline fused alumina abrasive are high.

Description

technical field [0001] The invention relates to the field of inorganic non-metallic materials, in particular to a method for preparing pseudo-boehmite and microcrystalline corundum abrasives. Background technique [0002] Microcrystalline corundum abrasive is a high-performance wear-resistant material, suitable for grinding occasions that require high grinding efficiency and precision, especially for grinding high-strength and high-hardness materials. The abrasive is a microcrystalline ceramic abrasive whose main component is alumina (Al 2 o 3 ), the grain size is generally required to be below 0.5 μm, so the hardness is high, the toughness is good, the breakage rate is low, the self-sharpening is good, and the service life can reach conventional abrasives (white corundum, brown corundum, single crystal corundum, chrome corundum, silicon carbide, etc. ) is several times longer than the service life, and it is not easy to cause burns of the ground material. [0003] The pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/02C09K3/14
Inventor 秦桂文
Owner SHANGHAI SHANGMO ABRASIVES & GRINDING TOOL
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