阅读说明：本技术 一种高纯纳米氧化铝的制备方法 (Preparation method of high-purity nano aluminum oxide ) 是由 姜鹏俊 姜起盛 姜起腾 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种高纯纳米氧化铝的制备方法,将高纯白色结晶氯化铝分装在氧化铝陶瓷坩埚中,氧化铝焙烧坩埚中添加有一层氧化铝穿孔式晶体纤维板,并通过加水使其达到饱和状态,氯化铝位于氧化铝穿孔式晶体纤维板上面,将其送入自动辊道窑内进行焙烧,根据需要的产品类型选择焙烧温度,将焙烧后的氧化铝用智能化机械手倒入加入旋风陶瓷粉碎机中粉碎,并且在旋风陶瓷粉碎机中设置加热装置进行烘干除氯,经过二次烘干粉碎除氯,得到粉体,再将此粉体气流粉碎,得到纳米级高纯氧化铝产品。本发明通过一次湿法高温焙烧,二次旋风陶瓷粉碎除氯烘干,经过气流粉碎,包装出售,可依据不同客户的需求焙烧成高纯γ氧化铝和α氧化铝,工艺简单,纯度高。(The invention discloses a preparation method of high-purity nano alumina, which comprises the steps of subpackaging high-purity white crystalline aluminum chloride in an alumina ceramic crucible, adding a layer of alumina perforated crystal fiber board in the alumina roasting crucible, adding water to enable the alumina perforated crystal fiber board to reach a saturated state, placing the aluminum chloride on the alumina perforated crystal fiber board, feeding the aluminum chloride into an automatic roller kiln for roasting, selecting roasting temperature according to the type of a required product, pouring the roasted alumina into a cyclone ceramic crusher by using an intelligent manipulator for crushing, arranging a heating device in the cyclone ceramic crusher for drying and dechlorinating, drying and crushing for the second time to remove chlorine, obtaining powder, and then carrying out airflow crushing on the powder to obtain a nano-grade high-purity alumina product. The invention adopts the primary wet method high-temperature roasting, the secondary cyclone ceramic crushing, dechlorination and drying, the airflow crushing, the packaging and the selling, and the invention can be roasted into high-purity gamma alumina and alpha alumina according to the requirements of different customers, and has simple process and high purity.)

1. A preparation method of high-purity nano alumina is characterized by comprising the following steps: high-purity white crystalline aluminum chloride is subpackaged in an alumina ceramic crucible, a layer of alumina perforated crystal fiberboard is added in an alumina roasting crucible, water is added to enable the alumina perforated crystal fiberboard to reach a saturated state, aluminum chloride is located on the alumina perforated crystal fiberboard and is sent into an automatic roller kiln to be roasted, water vapor passes through the aluminum chloride material, the hydrolysis speed is accelerated, the volatilization speed of HCl is improved, the roasting temperature is selected according to the type of a required product, roasted alumina is poured into a cyclone ceramic crusher by an intelligent manipulator to be crushed, a heating device is arranged in the cyclone ceramic crusher to be dried and dechlorinated, the chlorine is removed through secondary drying and crushing, powder is obtained, the powder is sent to a pneumatic ceramic crusher through a full-automatic cage grinder to be subjected to pneumatic crushing, and a nano-grade high-purity alumina product is obtained.

2. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: if gamma-alumina is needed, the roasting temperature is controlled at 360-480 ℃ for roasting, and the temperature is kept for 1-1.5h to obtain the gamma-alumina.

3. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: if alpha alumina is needed, the roasting temperature is controlled to be 1080-1160 ℃, and the high-purity alpha alumina is obtained after heat preservation for 1-2 h.

4. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: the alumina perforated crystal fiber board of the alumina ceramic crucible absorbs water in advance, and then aluminum chloride is added into the alumina ceramic crucible.

5. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: the feeding hopper of the cyclone ceramic crusher is provided with a heating jacket, high-temperature steam is introduced into the heating jacket of the cyclone ceramic crusher to heat materials on the feeding hopper during crushing, so that residual chlorine and the steam react again, and hydrogen chloride is completely volatilized under the high-temperature condition.

6. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: and (3) carrying out water grinding on the product after jet milling to obtain the nano-grade high-purity aluminum oxide product, wherein the medium-diameter particle is less than or equal to 20-50nm, and the specific surface area is more than or equal to 50 square meters per gram.

7. The preparation method of high-purity nano alumina according to claim 1, which is characterized by comprising the following steps: and grinding the product subjected to jet milling, then spray drying and vacuum packaging to obtain the nano-alumina product.

Technical Field

The invention relates to the technical field of chemical industry, in particular to a preparation method of high-purity nano aluminum oxide.

Background

The enterprises for producing high-purity alumina by chemical methods in large scale in China are few, particularly the high-purity alumina with the purity of more than 5N mainly depends on the import from abroad, and even if the high-purity alumina can be produced, the production cost is high, the yield is low, and the market competitiveness is not high. At present, the domestic production process is generally a sintering method, a Bayer method and a Bayer sintering combination method. For example: CN200610033695.9 discloses a continuous preparation process of high-purity nano alumina, which comprises the steps of gasifying aluminum trichloride at high temperature, continuously passing through a premixer, fully mixing with hydrogen and oxygen, then entering a reaction chamber, carrying out high-temperature hydrolysis condensation reaction on the aluminum trichloride by utilizing high temperature and moisture generated by combustion of the hydrogen and the oxygen in the reaction chamber, and carrying out aggregation, gas-solid separation, dechlorination, flotation and other processes on a reaction product to obtain the high-purity nano alumina. CN201210436415.4 discloses a preparation method of 5N high-purity nano alumina powder, which is characterized by comprising the following steps of stirring and refluxing a 5N aluminum isopropoxide precursor, deionized water and a dispersing agent at a molar ratio of 1: 10-30: 0.5-2 at a temperature of 85-100 ℃ for hydrolysis reaction for 3-5 hours to obtain a hydrolysis mixture; evaporating the hydrolysis mixture at the temperature of 80-100 ℃ to obtain a byproduct isopropanol generated by the hydrolysis reaction and an azeotrope solution of the isopropanol and water, and performing centrifugal filtration on the product to obtain hydrated alumina; and transferring the hydrated alumina into a roasting furnace, drying at the temperature of 80-110 ℃ for 8-15 min, roasting at the temperature of 500-700 ℃ for 25-45 min to obtain 5N high-purity gamma-Al 2O3 powder with the granularity of 5-50 nm and the D50 of 25nm, then continuously heating to 1050-1200 ℃ for roasting for 30-50 min to obtain 5N high-purity alpha-Al 2O3 powder with the granularity of 10-100 nm and the D50 of 50 nm.

Disclosure of Invention

The invention aims to provide a preparation method of high-purity nano alumina, which mainly utilizes self-produced high-purity white crystalline aluminum chloride as a raw material (the content is more than 99.9 percent), and adopts the processes of primary wet high-temperature roasting, secondary cyclone ceramic crushing, dechlorination and drying, airflow crushing, packaging and selling. The process has the characteristics of large production scale and low cost, and can be roasted into high-purity gamma alumina and high-purity alpha alumina according to the requirements of different customers. The production process is bound to become a domestic leading production process, and has the significance of breaking through the foreign market monopoly, providing high-quality and low-price products for domestic enterprises and winning the international market competition.

In order to achieve the purpose, the invention adopts the following technical scheme: a process for preparing high-purity nano alumina includes loading high-purity white crystal aluminium chloride in alumina ceramic crucible, adding a layer of perforated crystal alumina fibre plate, adding water to saturation state, calcining aluminium chloride in said plate, passing water vapour through aluminium chloride to accelerate hydrolysis and increase the volatilization speed of HCl, choosing calcining temp, intelligent manipulator, pulverizing, hot air drying, removing chlorine, secondary drying, pulverizing to obtain powder, and airflow pulverizing, to obtain the nano-grade high-purity alumina product.

Further preferably, if gamma alumina is needed, the roasting temperature is controlled at 480 ℃ of 360-.

Further preferably, if alpha alumina is needed, roasting is carried out at the roasting temperature of 1080-1160 ℃, and the temperature is kept for 1-2h to obtain the alpha alumina.

Preferably, the alumina perforated crystal fiber plate of the alumina ceramic crucible absorbs water in advance, then aluminum chloride is added into the alumina ceramic crucible, water adsorbed in the alumina perforated crystal fiber plate is evaporated to form water vapor during roasting, chloride ions are taken away, water in the crystal fiber plate is slowly decomposed during roasting and reacts with the chloride ions in the aluminum chloride to generate HCl gas to be volatilized, and the purity of a roasted product is further improved.

Preferably, a heating jacket is arranged on a feeding hopper of the cyclone ceramic crusher, high-temperature steam is introduced into the heating jacket of the cyclone ceramic crusher to heat materials on the feeding hopper during crushing, so that residual chlorine and steam react again, hydrogen chloride is completely volatilized through high-temperature conditions, a high-purity product with the pH value of more than or equal to 6 is achieved, the acid value of the current domestic high-purity aluminum oxide with the pH value of less than or equal to 5-6 is broken, the problem that the use performance of equipment is corroded due to high pH acid is effectively solved, and meanwhile, drying, crushing and chlorine removal are carried out. .

Preferably, the product after jet milling is ground by water mill to obtain the nanometer grade high-purity alumina product, the medium-diameter particle is less than or equal to 20-50nm, and the specific surface area is more than or equal to 50 square meters per gram.

And further preferably, the product after jet milling is subjected to water milling and crushing, then spray drying and vacuum packaging to obtain the nanoscale high-purity aluminum oxide product.

The invention has the beneficial effects that: the aluminum chloride is converted into the aluminum oxide by one-time wet high-temperature roasting, and the water vapor stays on the surface of the aluminum chloride for a longer time during the roasting, so that the chloride ions of the residual aluminum chloride can be fully decomposed to form hydrogen chloride to be discharged. The roasted product alumina can not completely volatilize due to chloride ions, can absorb moisture in the air after being cooled to exist in the form of hydrogen chloride, and is subjected to secondary cyclone ceramic crushing, chlorine removal, drying and airflow crushing to obtain the high-purity nano alumina. The process has the characteristics of large production scale and low cost, and can be roasted into high-purity gamma alumina and high-purity alpha alumina according to the requirements of different customers.

Drawings

FIG. 1 is a process flow diagram of the present invention.

FIG. 2 is a schematic view of an alumina calcination crucible.

In the figure: 1. alumina roasting crucible, 2. perforated alumina crystal fiber board,

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.