阅读说明：本技术 一种拟薄水铝石的制备方法 (Preparation method of pseudo-boehmite ) 是由 关月明 张�成 杨刚 王永林 于 2018-08-01 设计创作，主要内容包括：本发明公开了一种拟薄水铝石的制备方法。该方法所采用的反应器为N个筒体套在一起形成套筒式反应器；所述筒体具有中空夹层结构,该套筒式反应器由外至内依次为第1筒体、第2筒体、……、第N筒体；第N筒体设有原料入口,第1筒体设有排出口,第2-第N筒体分别设有溢流口和溢流导管,第1-第N筒体分别设有气体入口；第N筒体内及相邻的两个筒体间均设有气体导管,气体导管上设有排气孔,该方法以含铝的酸性溶液与含氨气的混合气体进行反应来制备拟薄水铝石,制备的拟薄水铝石晶粒分布集中,经焙烧得到的氧化铝的孔结构可以满足渣油加氢催化剂载体要求,且整体工艺简单、易操作。(The invention discloses a preparation method of pseudo-boehmite. The reactor adopted by the method is a sleeve type reactor formed by sleeving N cylinder bodies together; the barrel is of a hollow sandwich structure, and the sleeve type reactor sequentially comprises a 1 st barrel, a 2 nd barrel, … … and an Nth barrel from outside to inside; the Nth cylinder is provided with a raw material inlet, the 1 st cylinder is provided with a discharge outlet, the 2 nd to Nth cylinders are respectively provided with an overflow port and an overflow conduit, and the 1 st to Nth cylinders are respectively provided with a gas inlet; the method is characterized in that an acid solution containing aluminum and a mixed gas containing ammonia react to prepare the pseudo-boehmite, the prepared pseudo-boehmite is concentrated in grain distribution, the pore structure of the alumina obtained by roasting can meet the requirements of a residual oil hydrogenation catalyst carrier, and the whole process is simple and easy to operate.)

1. A preparation method of pseudo-boehmite is characterized in that: the adopted reactor is a sleeve type reactor formed by sleeving N barrels; the barrel is of a hollow sandwich structure, and the sleeve type reactor sequentially comprises a 1 st barrel, a 2 nd barrel, … … and an Nth barrel from outside to inside; the Nth cylinder is provided with a raw material inlet, the 1 st cylinder is provided with a discharge outlet, the 2 nd to Nth cylinders are respectively provided with an overflow port and an overflow conduit, and the 1 st to Nth cylinders are respectively provided with a gas inlet; gas guide pipes are arranged in the Nth cylinder and between the two adjacent cylinders, and exhaust holes are formed in the gas guide pipes; the method comprises the following steps:

(1) preparing an acid solution containing aluminum;

(2) the method comprises the following steps that an aluminum-containing acidic solution enters an inner cavity of an Nth cylinder of a reactor from a raw material inlet of the reactor, meanwhile, a mixed gas containing ammonia is introduced into a hollow interlayer of the Nth cylinder of the reactor from a gas inlet of the Nth cylinder, the aluminum-containing acidic solution reacts with the mixed gas containing ammonia, then, slurry generated by the reaction enters the bottom of the Nth 1 th cylinder, meanwhile, the mixed gas containing ammonia is introduced into the hollow interlayer of the Nth-1 th cylinder of the reactor from a gas inlet of the Nth-1 th cylinder, the slurry continuously reacts with the mixed gas containing ammonia, and by analogy, the slurry sequentially enters an N-2 th cylinder, the.

(3) And (2) aging the slurry discharged from the cylinder 1 in an aging tank, and filtering, washing and drying the aged slurry to obtain the pseudoboehmite.

2. The method of claim 1, wherein: the N cylinders are cylinders with different diameters and same height, wherein N is a natural number greater than or equal to 3, preferably 3-5, the N cylinders share one cylinder bottom, and preferably the N cylinders are coaxially arranged.

3. The method of claim 1, wherein: the raw material inlet is positioned at the bottom of the Nth cylinder and is communicated with the inner cavity of the Nth cylinder.

4. The method of claim 1, wherein: the discharge port is positioned at the upper part of the 1 st cylinder body, and one or more discharge ports are arranged.

5. The method of claim 1, wherein: the overflow ports are positioned at the upper parts of the 2 nd to the Nth cylinder bodies, and the 2 nd to the Nth cylinder bodies are respectively provided with one or more overflow ports.

6. The method of claim 1, wherein: overflow ducts are arranged on the outer sides of the 2 nd to the Nth cylinders, the upper parts of the overflow ducts are communicated with the inner cavity of the cylinder through overflow ports, and the lower parts of the overflow ducts are communicated with the adjacent cylinder on the outer side of the cylinder through the lower opening of the overflow duct; preferably, the lower opening of the overflow conduit arranged at the lower part of the overflow conduit is positioned at the bottom of the cylinder body.

7. The method of claim 1, wherein: the gas inlets are positioned at the bottoms of the 1 st to the Nth cylinders and are respectively communicated with the hollow interlayer of the cylinder, and one or more gas inlets are respectively arranged at the bottom of each cylinder.

8. The method of claim 1, wherein: all be equipped with a plurality of gas conduits in the Nth barrel and between other adjacent two barrels, gas conduit level sets up, preferably divides multilayer level setting along the barrel axial, and further preferred gas conduit is along the radial level setting of barrel, and further preferred gas conduit evenly arranges in the barrel inner chamber.

9. The method of claim 1, wherein: two ends of the gas conduit in the Nth cylinder are respectively communicated with the hollow interlayer of the cylinder, one end of each gas conduit in the 1 st to the Nth-1 st cylinders is communicated with the hollow interlayer of the cylinder, and the other end is connected or connected with the outer side of the adjacent inner cylinder.

10. The method of claim 1, wherein: the acid solution containing aluminum in the step (1) is one or more of an aluminum chloride solution, an aluminum sulfate solution and an aluminum nitrate solution, and preferably an aluminum chloride solution; the concentration of the acid solution containing aluminum is Al₂O₃30-60 gAl₂O₃Preferably 40 to 50gAl₂O₃/L 。

11. The method of claim 1, wherein: the mixed gas containing ammonia in the step (2) is a mixed gas of air and/or inert gas and ammonia, wherein the volume concentration of ammonia in the mixed gas is 5-35%, and preferably 10-30%.

12. The method of claim 1, wherein: in the reaction process of the step (2), the pH value of the slurry discharged from each overflow port and each discharge port is controlled by adjusting the flow of the mixed gas containing ammonia gas, wherein the pH value of the slurry discharged from each discharge port is controlled to be 7.5-8.5, the pH value of the slurry discharged from each overflow port is controlled to be 3.0-7.0, and the pH value of the slurry discharged from the N-1 st cylinder is sequentially increased; preferably, the pH values of the slurry discharged from two adjacent cylinders are different by at least 0.5.

13. The method of claim 1, wherein: in the step (2), the reaction residence time of the reaction in each barrel of the N-1 st barrel is 15 min-30 min, and the total reaction residence time of the reaction in the N-1 st barrel is not more than 90 min; the reaction temperature of the reaction is 50-70 ℃, and preferably 55-65 ℃.

14. The method of claim 1, wherein: the aging conditions in the step (3) are as follows: the aging temperature is 50-90 ℃, and the aging time is 60-120 min; the drying conditions were as follows: the temperature is 100-150 ℃, and the drying time is 6-10 hours.

15. The method of claim 1, wherein: roasting the pseudo-boehmite for 4-7 hours at the temperature of 550-750 ℃, wherein the obtained alumina has the following properties: the pore volume is more than or equal to 1.0mL/g, and the specific surface area is more than or equal to 400m²(ii)/g; the pore distribution was as follows: the pore volume of the pores with the pore diameter less than 6nm accounts for 5-12% of the total pore volume, the pore volume of the pores with the pore diameter of 6-15 nm accounts for 65-80% of the total pore volume, and the pore volume of the pores with the pore diameter more than 15nm accounts for 10-23% of the total pore volume.

Technical Field

The invention relates to a preparation method of pseudo-boehmite.

Background

The alumina is of various types, e.g. gamma-Al₂O₃、η-Al₂O₃、θ-Al₂O₃、δ-Al₂O₃And α -Al₂O₃Etc. of which gamma-Al₂O₃The catalyst has the characteristics of large specific surface area, adjustable pore structure and good thermal stability, and is widely applied to the field of catalysis, particularly the field of catalytic hydrogenation. Preparation of gamma-Al₂O₃The common method is to prepare pseudo-boehmite and then to be baked and converted into gamma-Al at a certain temperature₂O₃. Pseudo-boehmite generally has three preparation methods in industry:

(1) neutralization of aluminum salts and bases, such as aluminum chloride:

AlCl₃+3NH₄OH→Al（OH）₃+3NH₄Cl；

(2) metathesis reactions of aluminum salts and aluminates, such as the aluminum sulfate process:

Al₂（SO₄）₃+6NaAlO₂+12H₂O→8Al（OH）₃+3Na₂SO₄。

(3) neutralization of aluminate with acid, such as carbonization:

2NaAlO₂+CO₂+3H₂O→2Al（OH）₃+Na₂CO₃；

the existing industrial preparation method mostly adopts a kettle type reactor batch colloid forming method to prepare the pseudoboehmite, so that the utilization rate of a device is reduced, the stability of the properties of each batch of materials cannot be ensured, and the subsequent catalyst preparation is influenced, particularly, the method for preparing the pseudoboehmite by taking ammonia water as a precipitator brings adverse effects to field operation and environment.

CN 103112878A discloses a method for preparing alumina with large specific surface area. The method comprises the steps of dissolving aluminum chloride solid in 0.1-0.5 mol/L sodium lauroyl glutamate aqueous solution at 20-50 ℃ to obtain 1-5 mol/L aluminum chloride solution; adding ammonia water or a mixed solution of the ammonia water and organic amine into an aluminum chloride solution, adjusting the pH value to 7-8, standing for 3-5 h, and crystallizing in a reaction kettle for 24-96 h; filtering, washing and roasting to obtain gamma-Al₂O₃The specific surface area can reach 240-400 m²/g。

CN 1425612A discloses a method for preparing activated alumina, which comprises preparing a mixed aqueous solution from aluminum chloride, ammonia water and pore-expanding agent ammonium oxalate or ammonium citrate, heating and concentrating the solution to generate aluminum hydroxide precipitate, drying and heating the precipitate to decompose and remove NH in the precipitate₄Cl, and roasting the obtained solid powder at 400-800 ℃ for 3-6 hours to convert the solid powder into gamma-Al₂O₃。

CN 103332716A discloses a preparation method of pseudoboehmite, which comprises the steps of firstly preparing an alcohol-water solution for later use; preparing an aluminum nitrate solution and an ammonia water solution by taking the prepared alcohol water solution as a solvent and respectively taking aluminum nitrate and ammonia water as solutes; and (3) dropwise adding an ammonia water solution into the aluminum nitrate solution, adjusting the pH value to 7-10, aging, filtering, washing for 2-6 times by using an alcohol water solution, and drying to obtain the pseudo-boehmite.

CN 107720792A discloses a preparation method of fibrous pseudo-boehmite, which drops ammonia water into Al (NO)₃)₃Or AlCl₃In the solution, until the pH value of the solution is 4-8, carrying out vacuum filtration and washing to obtain a precipitate; transferring the precipitate into a reactor, adding an aluminum sulfate solution, adding water for dilution, and carrying out hydrothermal reaction; and centrifugally separating, washing and drying the mixed solution after the hydrothermal reaction to obtain the fibrous pseudo-boehmite with the large specific surface area.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a preparation method of pseudo-boehmite, the pseudo-boehmite obtained by the method has centralized grain distribution, the pore structure of alumina obtained by roasting can meet the requirements of a residual oil hydrogenation catalyst carrier, and the method has simple process and easy operation.

The invention provides a preparation method of pseudo-boehmite, wherein an adopted reactor is a sleeve type reactor formed by sleeving N cylinders together; the barrel is of a hollow sandwich structure, and the sleeve type reactor sequentially comprises a 1 st barrel, a 2 nd barrel, … … and an Nth barrel from outside to inside; the Nth cylinder is provided with a raw material inlet, the 1 st cylinder is provided with a discharge outlet, the 2 nd to Nth cylinders are respectively provided with an overflow port and an overflow conduit, and the 1 st to Nth cylinders are respectively provided with a gas inlet; gas guide pipes are arranged in the Nth cylinder and between the two adjacent cylinders, and exhaust holes are formed in the gas guide pipes; the method comprises the following steps:

(1) preparing an acid solution containing aluminum;

(2) the method comprises the following steps that an aluminum-containing acidic solution enters an inner cavity of an Nth cylinder of a reactor from a raw material inlet of the reactor, meanwhile, a mixed gas containing ammonia is introduced into a hollow interlayer of the Nth cylinder of the reactor from a gas inlet of the Nth cylinder, the aluminum-containing acidic solution reacts with the mixed gas containing ammonia, then, slurry generated by the reaction enters the bottom of the Nth 1 th cylinder, meanwhile, the mixed gas containing ammonia is introduced into the hollow interlayer of the Nth-1 th cylinder of the reactor from a gas inlet of the Nth-1 th cylinder, the slurry continuously reacts with the mixed gas containing ammonia, and by analogy, the slurry sequentially enters an N-2 th cylinder, the.

(3) And (2) aging the slurry discharged from the cylinder 1 in an aging tank, and filtering, washing and drying the aged slurry to obtain the pseudoboehmite.

Further, the N cylinders are cylinders with different diameters and same height, wherein N is a natural number greater than or equal to 3, and preferably N is 3-5. The N cylinders share one cylinder bottom, and preferably, the N cylinders are coaxially arranged.

Furthermore, the raw material inlet is positioned at the bottom of the Nth cylinder and is communicated with the inner cavity of the Nth cylinder.

Further, the discharge port is positioned at the upper part of the 1 st cylinder, and one or more discharge ports can be arranged.

Furthermore, the overflow port is positioned at the upper part of the 2 nd to the Nth cylinder bodies, and the 2 nd to the Nth cylinder bodies are respectively provided with one or more overflow ports.

Furthermore, overflow conduits are arranged on the outer sides of the 2 nd to the Nth cylinders, the upper parts of the overflow conduits are communicated with the inner cavity of the cylinder through overflow ports, and the lower parts of the overflow conduits are communicated with the adjacent cylinder on the outer side of the cylinder through the lower openings of the overflow conduits. Preferably, the lower opening of the overflow conduit arranged at the lower part of the overflow conduit is positioned at the bottom of the cylinder body. Furthermore, the gas inlets are positioned at the bottoms of the 1 st to the Nth cylinders, the gas inlets are respectively communicated with the hollow interlayer of the cylinder, and the bottom of each cylinder is provided with one or more gas inlets.

Furthermore, a plurality of gas guide pipes are respectively arranged in the Nth cylinder body and between other adjacent two cylinder bodies, the gas guide pipes are horizontally arranged, preferably are horizontally arranged in multiple layers along the axial direction of the cylinder body, further preferably are horizontally arranged along the radial direction of the cylinder body, and are preferably uniformly distributed in the inner cavity of the cylinder body.

Furthermore, two ends of the gas conduit in the Nth cylinder are respectively communicated with the hollow interlayer of the cylinder, one end of each gas conduit in the 1 st to the Nth-1 st cylinders is communicated with the hollow interlayer of the cylinder, and the other end is connected or connected with the outer side of the adjacent inner-layer cylinder.

The acid solution containing aluminum in the step (1) is one or more of an aluminum chloride solution, an aluminum sulfate solution and an aluminum nitrate solution, and preferably an aluminum chloride solution; the concentration of the acid solution containing aluminum is Al₂O₃30-60 gAl₂O₃Preferably 40 to 50gAl₂O₃/L。

The acid solution containing aluminum reacts with the mixed gas containing ammonia in the step (2) to form the acid solution containing aluminum which contacts and reacts with the mixed gas containing ammonia discharged from the vent hole on the gas guide pipe in the upward horizontal pushing type moving process in the cylinder; the slurry reacts with the mixed gas containing ammonia gas by contacting the slurry with the mixed gas containing ammonia gas discharged from the vent holes on the gas guide pipe in the process of upward horizontal pushing movement in the cylinder body.

And (3) when the slurry enters the adjacent outer-layer cylinder from the inner-layer cylinder in the step (2) and rises to or above the overflow port of the inner-layer cylinder, the slurry flows into the bottom of the adjacent outer-layer cylinder from the overflow port through the overflow conduit.

The mixed gas containing ammonia in the step (2) is a mixed gas of air and/or inert gas and ammonia, wherein the volume concentration of ammonia in the mixed gas is 5-35%, and preferably 10-30%.

In the reaction process of the step (2), the pH value of the slurry discharged from each overflow port and each discharge port is controlled by adjusting the flow of the mixed gas containing ammonia gas, wherein the pH value of the slurry discharged from each discharge port is controlled to be 7.5-8.5, the pH value of the slurry discharged from each overflow port is controlled to be 3.0-7.0, and the pH value of the slurry discharged from the N-1 st cylinder is sequentially increased; preferably, the pH values of the slurry discharged from two adjacent cylinders are different by at least 0.5.

In the step (2), the reaction residence time of the reaction in each barrel of the N-1 st barrel is 15-30 min, the total reaction residence time of the reaction in the N-1 st barrel is not more than 90min, and the reaction temperature of the reaction is 50-70 ℃, preferably 55-65 ℃.

The aging conditions in the step (3) are as follows: the aging temperature is 50-90 ℃, the aging time is 60-120 min, and the drying conditions are as follows: the temperature is 100-150 ℃, and the drying time is 6-10 hours.

In the process of preparing the pseudo-boehmite, an auxiliary agent, such as one or more of Si, P, B or Ti, can be added according to the requirement, wherein the mass content of the auxiliary agent is 2-6% of the pseudo-boehmite obtained by the oxide.

The pseudo-boehmite obtained by the invention is roasted for 4-7 hours at the temperature of 550-750 ℃, and the properties of the obtained alumina are as follows: the pore volume is more than or equal to 1.0mL/g, and the specific surface area is more than or equal to 400m²(ii)/g; the pore distribution was as follows: the pore volume of the pores with the pore diameter less than 6nm accounts for 5-12% of the total pore volume, the pore volume of the pores with the pore diameter of 6-15 nm accounts for 65-80% of the total pore volume, and the pore volume of the pores with the pore diameter more than 15nm accounts for 10-23% of the total pore volume.

The method of the invention has the following advantages:

(1) the method adopts the specific sleeve type reactor to prepare the pseudoboehmite, prolongs the traveling path of the raw materials in the reactor, leads the mixed gas to enter the reactor for reaction in a layering, grading, multiple times and multiple points, improves the utilization rate of the gas and overcomes the defect of small pore volume caused by the concentrated heat release of the gas in the production process of the prior art; the fluid flow moves forward regularly in a flat push mode, and the phenomena of serious back mixing, disturbance and the like can not occur; meanwhile, the raw material and the gas can be fully mixed, the obtained pseudoboehmite grains are distributed and concentrated, and the pore structure obtained by roasting meets the requirements of a residual oil hydrogenation catalyst carrier.

(2) The invention takes ammonia gas as a precipitator, the precipitator is mixed with air and/or inert gas and enters the reactor in a gas form to react with the acid solution containing aluminum, and the adverse effect of ammonia water on site operation and environment is overcome.

(3) The invention realizes the preparation of the pseudo-boehmite by the continuous method, and the method has simple process and easy operation.

Drawings

FIG. 1 is a graph showing the particle diameter distribution of pseudo-boehmite obtained in examples 1, 3 and 5 of the present invention and comparative example 1;

FIG. 2 is a cross-sectional view of a reactor of the present invention;

FIG. 3 is a top view of a reactor of the present invention;

the reference numerals are explained below:

1-cylinder, 2-cylinder outside, 3-cylinder inside, 4-overflow port, 5-discharge port, 6-overflow conduit, 7-gas conduit, 8-exhaust hole, 9-cylinder bottom, 10-raw material inlet, 11-gas inlet, 11_-33 rd cylinder gas inlet, 11_-22 nd cylinder gas inlet, 11_-1-1 st cylinder gas inlet.

Detailed Description

The following embodiments are described in further detail with reference to the accompanying drawings, and the following examples are provided to illustrate the technical solutions of the present invention, but not to limit the scope of the present invention.

The reactor provided by the invention, as shown in figures 2 and 3, is a sleeve type reactor formed by sleeving 3 cylinders; the barrel 1 is of a hollow sandwich structure, and the sleeve type reactor sequentially comprises a 1 st barrel, a 2 nd barrel and a 3 rd barrel from outside to inside; the 3 rd cylinder is provided with a raw material inlet, the 1 st cylinder is provided with a discharge port 5, the 2 nd and 3 rd cylinders are respectively provided with an overflow port 4 and an overflow conduit 6, and the 1 st to 3 rd cylinders are respectively provided with a gas inlet 11_-1、11_-2、11_-3(ii) a Gas conduits 7 are arranged in the 3 rd cylinder body, between the 1 st cylinder body and the 2 nd cylinder body, and between the 2 nd cylinder body and the 3 rd cylinder body,the gas guide pipe is provided with a vent hole 8.

The 3 barrels are cylindrical barrels with different diameters and the same height, the 3 barrels share one barrel bottom, and the 3 barrels are coaxial.

The raw material inlet 10 is positioned at the bottom of the 3 rd cylinder body and is communicated with the inner cavity of the 3 rd cylinder body.

The discharge ports 5 are positioned at the upper part of the 1 st cylinder body, and 2 discharge ports are arranged.

The overflow port 4 is positioned at the upper parts of the 2 nd cylinder body and the 3 rd cylinder body, and the 2 nd cylinder body and the 3 rd cylinder body are respectively provided with 2 overflow ports.

And overflow guide pipes 6 are arranged on the outer sides of the 2 nd and 3 rd cylinders, the upper parts of the overflow guide pipes 6 are communicated with the inner cavity of the cylinder through overflow ports, the lower parts of the overflow guide pipes are communicated with the adjacent cylinder on the outer side of the cylinder through lower openings of the overflow guide pipes, and the lower openings of the overflow guide pipes arranged on the lower parts of the overflow guide pipes are positioned at the bottom of the cylinder.

And gas inlets 11 arranged at the bottoms of the 1 st to 3 rd cylinder bodies are respectively communicated with the hollow interlayer of the cylinder body, and the bottom of each cylinder body is respectively provided with 2 gas inlets.

A plurality of gas conduits 7 are respectively arranged in the 3 rd cylinder body and between two adjacent cylinder bodies, the gas conduits 7 are horizontally arranged in multiple layers along the axial direction of the cylinder body, and each layer of gas conduit is horizontally arranged along the radial direction and is uniformly distributed in the inner cavity of the cylinder body. Two ends of the gas conduit in the No. 3 cylinder are respectively communicated with the hollow interlayer of the cylinder, one end of each gas conduit in the No. 1 and No. 2 cylinders is communicated with the hollow interlayer of the cylinder, and the other end is radially connected with the outer side 2 of the inner cylinder adjacent to the gas conduit.

The method for preparing the pseudo-boehmite by utilizing the reactor comprises the following steps: continuously injecting aluminum-containing acid salt solution into the raw material inlet 10 of the sleeve type reactor and simultaneously injecting aluminum-containing acid salt solution into the gas inlet 11 of the 3 rd cylinder of the sleeve type reactor_-3Introducing mixed gas containing ammonia, reacting aluminum-containing acid salt solution with the mixed gas containing ammonia discharged from the exhaust holes 8 of the gas guide pipes 7 in each layer in the upward horizontal pushing type moving process of the aluminum-containing acid salt solution in the cylinder 3, and when slurry generated by the reaction rises to the overflow port 4 or is higher than the overflow port 4, flowing the slurry from the overflow port 4 into the bottom of the cylinder 2 of the sleeve type reactor through the overflow guide pipe 6 and passing throughAdjusting the flow of the mixed gas, controlling the pH value of the flowing slurry, and controlling the reaction temperature; when the slurry flows into the bottom of the No. 2 cylinder of the sleeve type reactor, the gas inlet 11 of the No. 2 cylinder of the sleeve type reactor_-2Introducing mixed gas containing ammonia, reacting the slurry with the mixed gas discharged from the exhaust holes 8 of the gas guide pipes 7 of all layers in the process of upward horizontal pushing movement in the cylinder 2, when the slurry generated by the reaction rises to the overflow port 4 or is higher than the overflow port 4, enabling the slurry to flow into the bottom of the cylinder 1 from the overflow port 4 through the overflow guide pipe 6, controlling the pH value of the flowing slurry by adjusting the flow of the mixed gas, and controlling the reaction temperature; when the slurry flows into the bottom of the 1 st cylinder, the gas inlet 11 of the 1 st cylinder of the sleeve type reactor is communicated with the gas inlet of the 1 st cylinder_-1Introducing mixed gas containing ammonia, reacting the slurry with the mixed gas discharged from the exhaust holes 8 of the gas guide pipes 7 of each layer in the upward horizontal pushing movement process in the cylinder 1, discharging the slurry out of the reactor from the end point slurry discharge hole 5 when the slurry generated by the reaction rises to the end point slurry discharge hole 5, controlling the pH value of the end point of the slurry by adjusting the flow rate of the mixed gas, and controlling the reaction temperature; and (3) aging the slurry discharged out of the reactor in an aging tank, filtering, washing and drying after aging to obtain the pseudoboehmite.