CN1477059A

CN1477059A - Preparation method of nano alumina material

Info

Publication number: CN1477059A
Application number: CNA031290841A
Authority: CN
Inventors: 张良苗; 陈念贻; 陆文聪
Original assignee: University of Shanghai for Science and Technology
Current assignee: Shanghai University; University of Shanghai for Science and Technology
Priority date: 2003-06-05
Filing date: 2003-06-05
Publication date: 2004-02-25
Anticipated expiration: 2023-06-05
Also published as: CN1186261C

Abstract

The present invention relates to a nano alumina material, and its production method includes the following steps: using sodium aluminate and sodium hydrogen carbonate solutions to make them directly implement reaction, then filtering, dispersing, washing and adding acid to make beat-dispersion and ageing to obtain the transparent sol for preparing nano alumina material, and using said sol to directly produce nano alumina powder or nano alumina ceramic filter membrane.

Description

Method for manufacturing nano aluminum oxide material

Technical Field

The invention relates to a nano aluminum oxide material which is nano α -Al₂O₃And (3) pulverizing. The invention also relates to a nano alumina ceramic filter membrane.

Background

α -alumina nano powder is a raw material for producing alumina ceramics with a certain degree of toughness, which attracts the wide attention of the nano material industry, at present, the preparation method of alumina nano materials needs expensive raw materials (such as alkoxide, aluminum chloride, aluminum nitrate, etc.) or grinding technology with strict technical requirements, so the cost is high.

Disclosure of Invention

The invention aims to provide nano α -Al₂O₃And (3) pulverizing.

The invention also aims to provide a nano alumina ceramic filter membrane.

The invention is realized by the following steps:

1) slowly adding the sodium aluminate solution subjected to desiliconization in the alumina industrial production into a large amount of sodium bicarbonate solution at room temperature, and stirring for reaction until the pH value is between 8.0 and 11.0;

2) filtering the generated colloidal precipitate, and washing with deionized water;

3) dispersing and washing with deionized water at the temperature of 40-100 ℃, and then washing with dilute nitric acid;

4) placing the colloidal precipitate in deionized water, heating and stirring, adding acid to dissolve the colloid, wherein the amount of the acid should be controlled to be not less than 0.36H⁺/Al³⁺The molar ratio is more than or equal to 0.12, the temperature is controlled to be 80-100 ℃, and the pH value is controlled to be 2.5-4.5;

5) aging the sol at a constant temperature of 60-100 ℃ for 6-18 h, and adjusting the pH value to keep the pH value unchanged to obtain stable transparent sol;

6) adding n-butanol into the sol, performing azeotropic distillation, distilling at 90-120 deg.C to obtain azeotrope of water and n-butanol and excessive n-butanol, distilling to obtain loose dry powder, and burning at 1200 deg.C for 3 hr to obtain nanometer α -Al₂O₃And (3) pulverizing.

Another task of the present invention is achieved by:

4) placing the colloidal precipitate in deionized water, heating and stirring, adding acid, and beating to dissolve the colloid, wherein the amount of the acid added should be controlledH is not less than 0.36⁺/Al³⁺The molar ratio is more than or equal to 0.12, the temperature is controlled to be 80-100 ℃, and the pH value is controlled to be 2.5-4.5;

6) uniformly dipping the sol on the surface of the treated alumina porous ceramic tube by using a dipping-pulling method, drying the sol for 24 hours at room temperature, gradually heating the sol to 500 ℃, and calcining the sol for 2 hours to obtain the nano alumina ceramic filter membrane.

At present, there are many alumina plants produced as raw material of metallic aluminium in China in large scale, the annual output is millions of tons, most of them adopt the combination method or soda lime sintering method to produce, there are huge sodium aluminate circulating liquid and carbon content mother liquid (sodium carbonate concentrated solution), when carbon content mother liquid, ready-made carbonating raw material carbon dioxide circulating gas and ready-made carbonating equipment are used to recover rare-dispersed gallium, the carbon content mother liquid is very easy to be further carbonated into sodium bicarbonate solution, we use these two solutions of alumina plants to interact to produce nano α -Al₂O₃Powder or nano alumina ceramic filter membrane. The reaction is as follows:

the advantage is that cheap and ready-made raw materials of sodium aluminate and sodium bicarbonate solution are adopted in alumina plant, the main materials can be recycled, and besides small amount of acid consumption during degumming, the raw material cost is far lower than that of the existing nano α -Al byproduct, as the byproduct of alumina plant, the raw material cost is far lower₂O₃Powder or nano alumina ceramic filter membrane, and is suitable for mass production.

Detailed Description

The first embodiment is as follows: at room temperature, 0.32L of sodium aluminate solution after desiliconization in industrial production is taken, and 4L of saturated NaHCO is slowly added₃While stirring, the solution was measured for pH. The addition was stopped when the pH reached 8.75. Generated sedimentFiltering and washing the precipitate, transferring to hot water of 60 ℃ for dispersion, then filtering, washing with hotwater, and then washing with dilute nitric acid. Dissolving the precipitate in distilled water, stirring, heating to about 90 deg.C, adjusting pH with 0.07mol/L dilute acetic acid, and adding acid at a ratio of H⁺/Al³⁺The pH value is controlled to be about 3.5 when the pH value is 0.15. Aging at 80 deg.C for 6h to obtain stable transparent sol. Will contain Al₂O₃Heating and distilling 10% sol 200g and 400mL n-butanol, distilling off azeotrope of water and n-butanol and excessive n-butanol at 90-120 deg.C, pouring out pale yellow loose powder, and burning at 1200 deg.C for 3 hr to obtain nanometer α -Al powder of about 30nm₂O₃And (3) pulverizing.

Example two: at room temperature, 0.32L of sodium aluminate solution after desiliconization in industrial production is taken, and 4L of saturated NaHCO is slowly added₃While stirring, the solution was measured for pH. The addition was stopped when the pH reached 9.5. Generated byFiltering and washing the precipitate, transferring the precipitate to hot water of 80 ℃ for dispersion, then filtering, washing with hot water, and then washing with dilute nitric acid. Dissolving the precipitate in distilled water, stirring, heating to about 80 deg.C, adjusting pH with 0.10mol/L dilute hydrochloric acid, and adding acid at a ratio of H⁺/Al³⁺The pH value is controlled to be about 3.7 when the pH value is 0.20. Aging at 70 deg.C for 10h to obtain stable transparent sol. Will contain Al₂O₃Heating and distilling 10% sol 200g and n-butanol 400mL, distilling off azeotrope of water and n-butanol and excessive n-butanol at 90-120 deg.C, pouring out pale yellow loose powder, and burning at 1200 deg.C for 3 hr to obtain nanometer α -Al powder of about 30nm₂O₃And (3) pulverizing.

Example three: at room temperature, 0.32L of sodium aluminate solution afterdesiliconization in industrial production is taken, and 4L of saturated NaHCO is slowly added₃While stirring, the solution was measured for pH. The addition was stopped when the pH reached 10.9. The generated precipitate is filtered and washed, then transferred to hot water with the temperature of 70 ℃ for dispersion, and then filtered, washed by the hot water and washed by dilute nitric acid. Dissolving the precipitate in distilled water, stirring, heating to about 100 deg.C, and adding 0.14mol/LDilute nitric acid is added to regulate pH value, and the acid proportion is H⁺/Al³⁺The pH value is controlled to be about 4.3 when the pH value is 0.25. Aging at 60 deg.C for 16h to obtain stable transparent sol. Will contain Al₂O₃Heating and distilling 10% sol 200g and 400mL n-butanol, distilling off azeotrope of water and n-butanol and excessive n-butanol at 90-120 deg.C, pouring out pale yellow loose powder, and burning at 1200 deg.C for 3 hr to obtain nanometer α -Al powder of about 30nm₂O₃And (3) pulverizing.

Example four: at room temperature, 0.32L of sodium aluminate solution after desiliconization in industrial production is taken, and 4L of saturated NaHCO is slowly added₃While stirring, the solution was measured for pH. The addition was stopped when the pH reached 10.7. The generated precipitate is filtered and washed, then transferred to hot water with the temperature of 70 ℃ for dispersion, and then filtered, washed by the hot water and washed by dilute nitric acid. Dissolving the precipitate in distilled water, stirring, heating to about 100 deg.C, adjusting pH with 0.12mol/L dilute nitric acid, and adding acid at a ratio of H⁺/Al³⁺The pH value is controlled to be about 3.7 when the pH value is 0.20. Aging at 60 deg.C for 16h to obtain stable transparent sol.

Placing a section of alumina porous ceramic tube with the length of 80-100mm, the diameter of 10mm, the aperture of 50um and the porosity of 50% in 1mol/L NaOH to boil for 30 minutes, and washing with distilled water to be neutral; then 1mol/L HNO is used₃Boiling for 30 minutes, washing to be neutral, and then drying at low temperature. Uniformly dipping the concentrated sol (2g/ml, 40-50 ℃) on the surface of an alumina porous ceramic tube by using a dipping-pulling method, drying for 24 hours at room temperature, gradually heating to 500 ℃ and calcining for 2 hours to obtain the nano alumina ceramic filter membrane.

Claims

1. A nanometer alumina material is nanometer α -Al₂O₃Powder, mainly manufactured by a sol method, characterized in that the method comprises the following steps:

a. slowly adding the sodium aluminate solution subjected to desiliconization in the alumina industrial production into a large amount of sodium bicarbonate solution at room temperature, and stirring for reaction until the pH value is between 8.0 and 11.0;

b. filtering the generated colloidal precipitate, and washing with deionized water;

c. dispersing and washing with deionized water at the temperature of 40-100 ℃, and then washing with dilute nitric acid;

d. placing the colloidal precipitate in deionized water, heating and stirring, adding acid to dissolve the colloid, wherein the amount of the acid should be controlled to be not less than 0.36H⁺/Al³⁺The molar ratio is more than or equal to 0.12, the temperature is controlled to be 80-100 ℃, and the pH value is controlled to be 2.5-4.5;

e. aging the sol at a constant temperature of 60-100 ℃ for 6-18 h, and adjusting the pH value to keep the pH value unchanged to obtain stable transparent sol;

f. adding n-butanol into the sol, performing azeotropic distillation, distilling at 90-120 deg.C to obtain azeotrope of water and n-butanol and excessive n-butanol, distilling to obtain loose dry powder, and burning at 1200 deg.C for 3 hr to obtain nanometer α -Al₂O₃And (3) pulverizing.

2. The nano alumina material as claimed in claim 1, which may be nano α -Al₂O₃The powder is characterized in that the added acid is acetic acid, hydrochloric acid or nitric acid.

3. The nanometer alumina material may be nanometer alumina ceramic filter membrane produced with sol process, and features the technological steps of:

d. placing the colloidal precipitate in deionized water, heating and stirring, adding acid to dissolve the colloid, wherein the amount of the acid should be controlled to be not less than 0.36H⁺/Al³⁺More than or equal to 0.12 (mol ratio), controlling the temperature at 80-100 ℃,controlling the pH value to be 2.5-4.5;

f. uniformly dipping the sol on the surface of the treated alumina porous ceramic tube by using a dipping-pulling method, drying the sol for 24 hours at room temperature, gradually heating the sol to 500 ℃, and calcining the sol for 2 hours to obtain the nano alumina ceramic filter membrane.

4. The nano alumina material as set forth in claim 3, which may be nano alumina ceramic filter membrane, and features the added acid of acetic acid, hydrochloric acid and nitric acid.