阅读说明：本技术 一种活性高纯氧化铝粉的制备方法 (Preparation method of active high-purity alumina powder ) 是由 刘光彦 丛佃凯 李昭静 王良坤 王成伟 高宏艳 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种活性高纯氧化铝粉的制备方法,包括以下步骤：1)将氢氧化铝粉末和氢氧化钠溶液混合,加压至0.1-0.4MPa,升温至110-140℃,反应2-6h,制得偏铝酸钠溶液；2)将步骤1)所得偏铝酸钠溶液与硫酸铝溶液并流加入到搅拌反应釜中,升温至30-60℃,开始反应,再加入碳酸钠溶液控制反应液pH为9-10,继续反应至反应完毕,升温至70-90℃,静置老化；3)将步骤2)老化后的混合液转移至高压釜中,增压至0.3-0.6MPa,升温至120-200℃,反应2-6h；4)对步骤3)产物进行洗涤、干燥、粉碎,即得。本发明方法制备的活性高纯氧化铝粉的孔径为8-10nm,比表面积为200-220m～2/g,孔容为0.5-0.6mL/g,且晶型好、纯度高,能够提高催化剂的稳定性和活性,可有效提高催化加氢的效率。(The invention discloses a preparation method of active high-purity alumina powder, which comprises the following steps: 1) mixing aluminum hydroxide powder and a sodium hydroxide solution, pressurizing to 0.1-0.4MPa, heating to 110-140 ℃, and reacting for 2-6h to prepare a sodium metaaluminate solution; 2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution into a stirring reaction kettle in a concurrent flow manner, heating to 30-60 ℃, starting to react, adding a sodium carbonate solution to control the pH of a reaction solution to be 9-10, continuing to react until the reaction is finished, heating to 70-90 ℃, standing and aging; 3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.3-0.6MPa, heating to 120-200 ℃, and reacting for 2-6 h; 4) and (3) washing, drying and crushing the product obtained in the step 3). The aperture of the active high-purity alumina powder prepared by the method is 8-10nm, and the specific surface area is 200-220m 2 The catalyst has the advantages of good crystal form and high purity, can improve the stability and activity of the catalyst, and can effectively improve the catalytic hydrogenation efficiency.)

1. The preparation method of the active high-purity alumina powder is characterized by comprising the following steps:

1) mixing aluminum hydroxide powder and a sodium hydroxide solution, pressurizing to 0.1-0.4MPa, heating to 110-140 ℃, and reacting for 2-6h to prepare a sodium metaaluminate solution;

2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution into a stirring reaction kettle in a concurrent flow manner, heating to 30-60 ℃, starting to react, adding a sodium carbonate solution to control the pH of a reaction solution to be 9-10, continuing to react until the reaction is finished, heating to 70-90 ℃, standing and aging;

3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.3-0.6MPa, heating to 120-200 ℃, and reacting for 2-6 h;

4) and (3) washing, drying and crushing the product obtained in the step 3).

2. The method according to claim 1, wherein the concentration of the sodium hydroxide solution in step 1) is 25 to 40 wt.%.

3. The method of claim 1, wherein the molar ratio of the aluminum hydroxide to the sodium hydroxide in the step 1) is 1 (1.2-1.6).

4. The method as claimed in claim 1, wherein in the step 2), the concentration of the alumina in the aluminum sulfate solution is 20-100 g/L.

5. The method as claimed in claim 1, wherein the volume ratio of the sodium metaaluminate solution to the aluminum sulfate solution in the step 2) is 1 (0.1-1).

Technical Field

The invention relates to the field of catalyst carrier materials, in particular to a preparation method of active high-purity alumina powder.

Background

The high-purity active alumina powder is white powder, has uniform granularity, is easy to disperse, and has stable chemical property, high conversion rate and low sodium content. Meanwhile, the high-temperature shrinkage performance is moderate, the sintering performance is good, and the catalyst is widely applied to the field of catalysts. The acid-dissolved high-purity active alumina powder has adhesive property, and can be used as a binder to improve the strength of the catalyst, adjust the pore size distribution of the catalyst, improve the hydrothermal stability of the catalyst, adjust the acid active center density of the catalyst and improve the catalytic activity. It can also be widely used for preparing catalyst carriers for various reactions in chemical industry, oil refining and petrochemical industry, such as hydrofining catalyst carriers, reforming catalyst carriers, methanation catalyst carriers and the like. The high-purity active alumina powder can also be used as a catalyst after dehydration, and the gamma-alumina obtained after low-temperature roasting is used as a Claus sulfur recovery catalyst, an ethanol isomerization catalyst, an ethanol dehydration catalyst and the like. At present, the domestic production of high-purity active alumina powder is mainly based on a sodium aluminate solution carbonation method, and the medium and low-grade products are produced, so that the application of the high-purity active alumina powder in the field of catalysts is limited.

Disclosure of Invention

The invention provides a preparation method of active high-purity alumina powder based on the problems, which comprises the following steps: 1) mixing aluminum hydroxide powder and a sodium hydroxide solution, pressurizing to 0.1-0.4MPa, heating to 110-140 ℃, and reacting for 2-6h to prepare a sodium metaaluminate solution; 2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution into a stirring reaction kettle in a concurrent flow manner, heating to 30-60 ℃, starting to react, adding a sodium carbonate solution to control the pH of a reaction solution to be 9-10, continuing to react until the reaction is finished, heating to 70-90 ℃, standing and aging; 3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.3-0.6MPa, heating to 120-200 ℃, and reacting for 2-6 h; 4) and (3) washing, drying and crushing the product obtained in the step 3).

In the step 1), the concentration of the sodium hydroxide solution is 25-40 wt%; the molar ratio of the aluminum hydroxide to the sodium hydroxide is 1 (1.2-1.6).

In the step 2), the concentration of alumina in the aluminum sulfate solution is 20-100 g/L; the volume ratio of the sodium metaaluminate solution to the aluminum sulfate solution is 1 (0.1-1).

The invention has the beneficial effects that: the aperture of the active high-purity alumina powder prepared by the method is 8-10nm, and the specific surface area is 200-220m²The catalyst has the advantages of good crystal form and high purity, can improve the stability and activity of the catalyst, and can effectively improve the catalytic hydrogenation efficiency.

Detailed Description

The present invention is described below with reference to examples, which are provided for illustration only and are not intended to limit the scope of the present invention.

Example 1

A preparation method of active high-purity alumina powder comprises the following steps: 1) mixing aluminum hydroxide powder and a sodium hydroxide solution with the concentration of 25 wt%, controlling the molar ratio of aluminum element to sodium element to be 1:1.6, pressurizing to 0.1MPa, heating to 140 ℃, and reacting for 6 hours to prepare a sodium metaaluminate solution; 2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution with the concentration of alumina being 100g/L into a stirring reaction kettle in a concurrent flow mode according to the volume ratio of 1:1, heating to 60 ℃, starting reaction, adding a sodium carbonate solution to control the pH of a reaction solution to be 9, heating to 70 ℃ after the reaction is finished, standing and aging; 3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.6MPa, heating to 200 ℃, and reacting for 2 hours; 4) and (3) washing, drying and crushing the product obtained in the step 3).

Example 2

A preparation method of active high-purity alumina powder comprises the following steps: 1) mixing aluminum hydroxide powder and a sodium hydroxide solution with the concentration of 35 wt%, controlling the molar ratio of aluminum element to sodium element to be 1:1.2, pressurizing to 0.25MPa, heating to 130 ℃, and reacting for 4 hours to prepare a sodium metaaluminate solution; 2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution with the concentration of aluminum oxide of 60g/L into a stirring reaction kettle in a concurrent flow manner according to the volume ratio of 1:0.1, heating to 30 ℃, starting reaction, adding a sodium carbonate solution to control the pH of the reaction solution to be 9.5, heating to 80 ℃ after the reaction is finished, standing and aging; 3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.3MPa, heating to 120 ℃, and reacting for 6 hours; 4) and (3) washing, drying and crushing the product obtained in the step 3).

Example 3

A preparation method of active high-purity alumina powder comprises the following steps: 1) mixing aluminum hydroxide powder and a sodium hydroxide solution with the concentration of 45 wt%, controlling the molar ratio of aluminum element to sodium element to be 1:1.4, pressurizing to 0.4MPa, heating to 110 ℃, and reacting for 2 hours to prepare a sodium metaaluminate solution; 2) adding the sodium metaaluminate solution obtained in the step 1) and an aluminum sulfate solution with the concentration of 20g/L of alumina into a stirring reaction kettle in a concurrent flow manner according to the volume ratio of 1:0.6, heating to 45 ℃, starting reaction, adding a sodium carbonate solution to control the pH of the reaction solution to be 10 and the temperature to be 45 ℃, heating to 90 ℃ after the reaction is finished, standing and aging; 3) transferring the aged mixed solution obtained in the step 2) into an autoclave, pressurizing to 0.45MPa, heating to 160 ℃, and reacting for 4 hours; 4) and (3) washing, drying and crushing the product obtained in the step 3).

Table 1 shows the index measurements of the activated high purity alumina powders obtained in examples 1-3.

TABLE 1 indices of activated high purity alumina powders obtained in examples 1-3

	Example 1	Example 2	Example 3
				Al2O3m％	77.75	76.41	76.68
Specific surface m2/g	227	228	218
				Pore volume ml/g	0.51	0.5	0.5
Average pore diameter nm	8.93	8.75	9.2
				Peptization index m%	95.91	93.33	94.09

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.