Continuous preparation process of high purity nanometer alumina

Abstract

The continuous preparation process of high purity nanometer alumina includes the following steps: high temperature gasifying aluminum trichloride, continuous mixing with H2 and O2 in a re-mixer, high temperature hydrolysis and condensation reaction of aluminum trichloride in the high temperature generated through burning H2 inside a reactor, and aggregating the reaction product, gas-solid separation, dechlorinating, floating, etc. to obtain high purity nanometer alumina. By means of controlling the material ratio, the cooling rate in the reactor, and the length and temperature of the aggregator, nanometer alumina powder of different grain sizes may be obtained. By means of tail gas treatment, circular utilization of aluminum trichloride and absorption of HCl to prepare hydrochloric acid, the present invention realizes the best utilization of resource.

Description

Technical field

[0001] The invention relates to a continuous preparation process of high-purity nano alumina. Background technique

[0002] As a new type of high-functional fine inorganic material, nano-alumina is widely used in the fields of catalysis, ceramics, cutting tools, aerospace and functional materials due to its high hardness, high heat resistance and corrosion resistance. The preparation methods of high-purity nano alumina currently reported mainly include sol-gel method, liquid phase precipitation method, micro-emulsion method, aluminum alkoxide hydrolysis method, aluminum ammonium sulfate thermal decomposition method, critical liquid drying method, electrochemical method, etc. . These methods all need to first precipitate the aluminum ions in the solution to prepare the alumina precursor, and then obtain the nano-alumina products through processes such as cleaning, drying, and high-temperature calcination. Therefore, these preparation methods can be summarized as pr...

Examples

Embodiment 1

[0022] Press the aluminum trichloride, hydrogen, and air to 5.5m 3 / h, 9.0m 3 / h、23.0m 3 The flow rate of / h (standard volume) is input to the premixer, and the reaction is carried out according to the above process. The temperature at the bottom of the reaction chamber (the entrance of the accumulator) is 950℃, the temperature in the first half of the accumulator is 950~600℃, and the temperature in the second half is 600~ 300°C. The temperature of the dechlorination tower is 350~500℃. The obtained nano alumina indicators are as follows:

[0023] Alumina content (%) 99.85 (atomic absorption spectrophotometer method)

[0024] Average particle size of primary particles (nm) 30 (electron microscope statistical method)

[0025] Chlorine content (%) 0.012 (potentiometric titration)

Embodiment 2

[0027] Press the aluminum trichloride, hydrogen, and air to 5.5m 3 / h、10m 3 / h、28m 3 The flow rate of / h (standard volume) is input to the premixer, and the reaction is carried out according to the above process. The temperature at the bottom of the reaction chamber (at the entrance of the accumulator) is 800℃, the temperature in the first half of the accumulator is 800~550℃, and the temperature in the second half is 550~ 300°C. The temperature of the dechlorination tower is 350~500℃. The obtained nano alumina indicators are as follows:

[0028] Alumina content (%) 99.90 (atomic absorption spectrophotometer method)

[0029] Average particle size of primary particles (nm) 12 (electron microscope statistical method)

[0030] Chlorine content (%) 0.018 (potentiometric titration).

Technical field

[0001] The invention relates to a continuous preparation process of high-purity nano alumina. Background technique

[0002] As a new type of high-functional fine inorganic material, nano-alumina is widely used in the fields of catalysis, ceramics, cutting tools, aerospace and functional materials due to its high hardness, high heat resistance and corrosion resistance. The preparation methods of high-purity nano alumina currently reported mainly include sol-gel method, liquid phase precipitation method, micro-emulsion method, aluminum alkoxide hydrolysis method, aluminum ammonium sulfate thermal decomposition method, critical liquid drying method, electrochemical method, etc. . These methods all need to first precipitate the aluminum ions in the solution to prepare the alumina precursor, and then obtain the nano-alumina products through processes such as cleaning, drying, and high-temperature calcination. Therefore, these preparation methods can be summarized as pr...

Examples

Embodiment 1

[0022] Press the aluminum trichloride, hydrogen, and air to 5.5m 3 / h, 9.0m 3 / h、23.0m 3 The flow rate of / h (standard volume) is input to the premixer, and the reaction is carried out according to the above process. The temperature at the bottom of the reaction chamber (the entrance of the accumulator) is 950℃, the temperature in the first half of the accumulator is 950~600℃, and the temperature in the second half is 600~ 300°C. The temperature of the dechlorination tower is 350~500℃. The obtained nano alumina indicators are as follows:

[0023] Alumina content (%) 99.85 (atomic absorption spectrophotometer method)

[0024] Average particle size of primary particles (nm) 30 (electron microscope statistical method)

[0025] Chlorine content (%) 0.012 (potentiometric titration)

Embodiment 2

[0027] Press the aluminum trichloride, hydrogen, and air to 5.5m 3 / h、10m 3 / h、28m 3 The flow rate of / h (standard volume) is input to the premixer, and the reaction is carried out according to the above process. The temperature at the bottom of the reaction chamber (at the entrance of the accumulator) is 800℃, the temperature in the first half of the accumulator is 800~550℃, and the temperature in the second half is 550~ 300°C. The temperature of the dechlorination tower is 350~500℃. The obtained nano alumina indicators are as follows:

[0028] Alumina content (%) 99.90 (atomic absorption spectrophotometer method)

[0029] Average particle size of primary particles (nm) 12 (electron microscope statistical method)

[0030] Chlorine content (%) 0.018 (potentiometric titration).

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