Method and device for removing hydrocarbons from a red mud calcified biomass eluate

Abstract

The application provides a method and device for removing hydrocarbons from a red mud calcified biomass solution, comprising: (1) crushing and grinding Bayer red mud, biomass and calcified compounds, stirring and mixing with circulating mother liquor or alkali liquor, and performing a leaching reaction on the mixed ore slurry; (2) performing sedimentation, separation and washing on the ore slurry after the leaching reaction to obtain a calcified biomass transformation residue and a separated liquid; the separated liquid contains hydrocarbons; (3) performing a reaction on the separated liquid in a reactor with oxygen-rich air to remove the hydrocarbons in the separated liquid, so that the hydrocarbons are converted into carbonates and water; (4) removing the reaction products through a precision filtration device after the reaction is completed to obtain a refined liquid which is returned to an alumina production system, and the filter residue is treated separately. The application strengthens the removal of hydrocarbons in the calcified biomass transformation process through the reaction of oxygen-rich air and hydrocarbons, thereby avoiding the adverse effects of the hydrocarbons on the subsequent seed decomposition process and the quality of the alumina product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of purification of red mud calcified biomass leaching solution, and particularly relates to a method and device for removing hydrocarbons from red mud calcified biomass leaching solution. BACKGROUND

[0002] With the rapid development of China's alumina industry, a large number of domestic enterprises use imported high-iron diaspore to produce, which has a high iron content, and the iron oxide in the red mud can be as high as more than 55%, and the comprehensive utilization efficiency is low.

[0003] In order to realize efficient recovery of iron, the present application proposes a method of converting the iron oxide into magnetite by using calcified biomass transformation. However, the concentration of hydrocarbons in the transformation liquid generated during the transformation process increases, which can cause problems such as reduced decomposition efficiency and decreased quality of alumina products.

[0004] A large number of studies have been conducted by domestic researchers on the removal of organic matter in the alumina production process. For example, the Yunnan Ecological Environment Science Research Institute invented a method for efficient removal of organic matter in Bayer alumina solution (CN114655972A), which involves extracting the Bayer alumina production mother liquor from the Bayer alumina production system, adding an oxidizing agent to it, and then controlling the reaction temperature under the combined action of photocatalysis and ultrasonic waves. After a period of time, the organic matter in the production mother liquor is crystallized in the form of oxalate from the mother liquor. After treatment, the production mother liquor is returned to the alumina production system after solid-liquid separation. This invention realizes efficient removal of organic matter in the Bayer alumina production mother liquor, and the color of the treated circulating mother liquor changes from dark brown to light green or colorless.

[0005] A method for removing organic matter in alumina production invented by Jingxi Tianguixi Aluminum Industry Co., Ltd. (CN113929124A) involves mixing the dust collected by the boiler burning coal and the fly ash from the coal gas furnace with the low-temperature evaporation mother liquor, and then settling the mixture. The sediment is sent to a filter press for pressure filtration, and the filter cake is sent to a red mud storage yard for storage or returned to the boiler for calcination. The filtrate after pressure filtration and the overflow from the settlement are returned to the production system.

[0006] The above-mentioned related methods either add additives to the Bayer solution or require additional processes and equipment, which can affect the production process to varying degrees. SUMMARY

[0007] The technical task of the present application is to overcome the shortcomings of the prior art and provide a method and device for removing hydrocarbons from red mud calcified biomass leaching solution, which can effectively remove the hydrocarbons dissolved from the Bayer red mud under the coupling action of calcification and biomass, and convert them into carbonates and water without the need for other additives and without causing pollution to the Bayer solution.

[0008] The technical scheme adopted by the present application to solve its technical problems is: a method for removing hydrocarbons from a red mud calcified biomass leaching solution, comprising the following steps:

[0009] (5) The Bayer process red mud is crushed and finely ground with biomass and a calcified compound, and is stirred and mixed with circulating mother liquor or lye. The mixed slurry is subjected to leaching reaction using a high-pressure leaching reactor (piping, external / internal stirring pipe type reaction kettle, etc.). The leaching and transformation of the Bayer process red mud are realized under the coupling effect of calcification and biomass. The slurry after leaching reaction contains hydrocarbons;

[0010] (6) The slurry after leaching reaction is subjected to sedimentation, separation and washing to obtain calcified biomass transformation slag and separated liquid. The separated liquid contains hydrocarbons;

[0011] (7) The separated liquid is reacted with oxygen-rich air in a reactor to remove the hydrocarbons in the separated liquid, so that the hydrocarbons are converted into carbonates and water;

[0012] (8) After the reaction is completed, the reaction products are removed by a precision filtration device to obtain a refined liquid which is returned to an aluminum oxide production system, and the filter residue is treated separately.

[0013] Further, the red mud in step (1) is a solid waste produced during the production of aluminum oxide by the Bayer process, wherein the mass fraction of Fe2O3 is 10-50%, and the mass fraction of sodium alkali is 1-10%; the calcified compound is one of calcium oxide, lime and carbide slag; the biomass is one or more of cassava powder, potato powder, corn starch, bagasse, wheat bran and rice straw; the circulating mother liquor or lye is the circulating mother liquor in the Bayer process or the prepared lye. The alkali concentration in the prepared lye and the circulating mother liquor is 200-350 g / L, and the caustic ratio α k = 2-15.

[0014] Further, the mass ratio of lime to silicon dioxide in the Bayer process red mud in step (1) is (1-4):1; the biomass accounts for 0.4%-2.4% of the solid mass in the mixed slurry of the Bayer process red mud, biomass, calcified compound and circulating mother liquor or lye; the ratio of the liquid volume to the solid mass of the slurry is ml:g = (6-9):1; the leaching temperature is 250-300°C, and the leaching time is 30-120 min. The transformation process removes the alkali in the red mud and recovers part of the aluminum oxide, and at the same time, the magnetite in the red mud is converted into magnetite. The circulating mother liquor or lye has residual hydrocarbons after being treated by the calcified biomass.

[0015] Further, the chemical content of alkali in the calcified biomass transformation slag in step (2) is less than 1 wt%, and the mass ratio of aluminum oxide to silicon oxide is less than 1.

[0016] Further, step (3) uses oxygen in the oxygen-rich air with a volume fraction of 30% to 100%, the inlet pressure ranges from 0.1 Mpa to 1 Mpa, the reaction temperature is 50 to 95℃, the residence time is 1 to 60 min, and the stirring speed is 50-200 rpm.

[0017] Further, after the completion of step (3), the removal rate of hydrocarbons in the separated liquid is greater than 90%.

[0018] Further, after the completion of step (4), the reaction product is removed by a precision filtration device, the precision filtration device is one of a plate and frame filter, a leaf filter, a rotary drum filter, and a belt filter, and the solid content removal rate of the filtrate after precision filtration is greater than 90%. The mother liquor after precision filtration is returned to the alumina production system, and the filter residue is treated separately.

[0019] The application also provides a device for removing hydrocarbons from a red mud calcified biomass solution, which is a tubular jet stirring reactor for the reaction of hydrocarbons in a red mud calcified biomass solution with oxygen-rich air. The tubular jet stirring reactor comprises a horizontal reaction cavity, a stirring shaft is arranged in the middle of the reaction cavity, a jet stirring paddle is arranged on the stirring shaft, a plurality of air holes are arranged on the jet stirring paddle, and the diameter of the air holes is 1-4 microns. The stirring shaft is a hollow structure and is connected to the jet stirring paddle. One end of the stirring shaft is connected to the output shaft of a stirring motor outside the reaction cavity, and the other end is arranged on the side wall of the reaction cavity and connected to a high-pressure gas circuit. An inlet and an outlet are arranged on the upper part of the reaction cavity, and an outlet is arranged on the lower part of the reaction cavity.

[0020] Further, the stirring shaft and the jet stirring paddle are integrally arranged.

[0021] Further, a plurality of air holes are arranged on the jet stirring paddle and the stirring shaft, and the diameter of the air holes is 1-4 microns.

[0022] Compared with the prior art, the application has the following advantages:

[0023] (1) In the high-pressure leaching reactor (tubular, external / internal stirring tubular reactor, etc.), the biomass is decomposed to generate organic substances with carbon-carbon double bond, carbon-carbon triple bond, carbon-oxygen double bond, etc. The iron-containing phase in the ore slurry is transformed into magnetite with high dissociation degree and suitable monomer particle size into the slag phase, and the calcareous compound can convert the alkali-containing phase in the balanced solid phase into an alkali-free solid phase. While effectively recovering Na2O and Al2O3, it also creates favorable conditions for the direct magnetic separation and efficient recovery of the subsequent iron phase; the recovery rate of alkali is more than 90%, the comprehensive recovery rate of iron and aluminum is more than 90%, the total iron grade of iron concentrate is more than 56%, and the tailings are reconstructed into a new type of red mud with low alkali, low aluminum, and low iron.

[0024] (2) the hydrocarbons in the separation liquid adopt a tubular jet stirring reactor as a removal device, the reactor is installed with a stirring paddle with air holes, a plurality of micrometer holes are opened on the stirring paddle, air is passed into the reactor from the stirring paddle micrometer holes, the purpose of strengthening removal of hydrocarbons by realizing bubble dispersion and refinement is achieved. The hydrocarbons in the secondary mother liquor (separation liquid) are removed by using oxygen-rich air, so that the hydrocarbons are converted into carbonates and water, no other additives are needed, and no Bayer process solution pollution is caused. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A schematic diagram of a tubular jet stirring reactor;

[0026] Figure 2 is a flow chart of the present application;

[0027] BRIEF DESCRIPTION OF DRAWINGS: 1 - air inlet; 2 - feed inlet; 3 - air outlet; 4 - stirring motor; 5 - discharge outlet; 6 - jet stirring paddle. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0029] The composition of the red mud used in the examples of the present application is as follows in terms of mass percentage: Al2O3-16.85%, SiO2-10.17%, Fe2O3-45.23%, the mass fraction of sodium alkali is 8%, and the balance is water, TiO2 and other impurities.

[0030] The production method described in the present application is not limited to this kind of red mud, and any raw material mainly composed of aluminum oxide and iron oxide can be treated by the method.

[0031] The composition of the lime used in the examples of the present application is as follows in terms of mass percentage: CaO-82.44%, SiO2-1.02%, Al2O3-2.14%, Fe-0.31%, and the balance is combined water and other impurities.

[0032] Example 1

[0033] A tubular jet stirring reactor is as follows Figure 1As shown, the reactor comprises a horizontal reaction cavity, a stirring shaft is arranged in the middle of the reaction cavity, and a jet stirring paddle is arranged on the stirring shaft. The jet stirring paddle 6 is provided with a plurality of air holes on the stirring shaft, and the diameter of the air holes is 1-4 microns. The stirring shaft is a hollow structure and is in communication with the jet stirring paddle. The stirring shaft and the jet stirring paddle are integrally arranged. One end of the stirring shaft is connected with the output shaft of the stirring motor 4 outside the reaction cavity, and the other end is arranged on the side wall of the reaction cavity and connected with the high-pressure gas path, i.e. the air inlet 1. The upper part of the reaction cavity is respectively provided with a feed inlet 2 and an air outlet 3, and the lower part of the reaction cavity is provided with a discharge outlet 5. The shaft is in communication with the air holes of the stirring paddle, and the shaft is in communication with the high-pressure gas path. Air is introduced into the reactor from the micro-holes in the stirring paddle to achieve the purpose of dispersing and refining the gas bubbles and strengthening the removal of hydrocarbons. Oxygen-enriched air is used to remove hydrocarbons in the secondary mother liquor, so that the hydrocarbons are converted into carbonates and water.

[0034] Example 2

[0035] The difference between this example and Example 1 is that only the jet stirring paddle is provided with a plurality of air holes, and the diameter of the air holes is 1-4 microns.

[0036] Based on the method for removing hydrocarbons in the red mud calcified biomass leaching solution of the tubular jet stirring reactor described in Example 1, the flow chart is as shown in Figure 2 The specific process is shown in the following examples.

[0037] Example 3

[0038] A method for removing hydrocarbons in a red mud calcified biomass leaching solution, comprising the following steps:

[0039] (1) The Bayer process red mud, cassava powder, lime and circulating mother liquor are rapidly mixed in a slurry tank. The concentration of the circulating mother liquor is 240 g / L, the caustic ratio a k = 4, the mass ratio of lime to silicon dioxide in the Bayer process red mud is 1:1, the biomass accounts for 2.4% of the solid mass after mixing, and the liquid-solid ratio ml:g of the slurry is 6:1.

[0040] (2) The reaction is carried out in an alkaline solution at 250°C for 30 minutes. The transformation process removes the alkali in the red mud and recovers part of the alumina. At the same time, the magnetite in the red mud can be converted into magnetite. After the circulating mother liquor is treated by the calcified biomass, the residual hydrocarbons remain in the mother liquor.

[0041] (3) After the reaction, the slurry is settled in a settling tank, then separated and washed to obtain a calcified biomass transformation residue and a separated liquid. The chemical content of alkali in the calcified biomass transformation residue is 0.9wt%, and the mass ratio of alumina to silicon dioxide is 0.85. The separated liquid contains hydrocarbons.

[0042] (4) The pipe jet stirring reactor is used as the removal device, the oxygen volume content in the oxygen-rich air is 30%, the inlet pressure is 0.1 MPa, the separation liquid is reacted with the oxygen-rich air in the pipe jet stirring reactor, the reaction temperature is 50°C, the residence time is 60 min, the stirring speed is 200 rpm, the removal rate of the hydrocarbons in the separation liquid is 91.23%, and the hydrocarbons are converted into carbonates and water.

[0043] (5) After the reaction is completed, the reaction product is removed through the precision filtration device, the precision filtration device is a plate and frame filter, the removal rate of the solid content in the filtrate after the precision filtration is 93%. The filtrate after the precision filtration is returned to the alumina production system, and the filter residue is treated separately.

[0044] Example 4

[0045] A method for removing hydrocarbons in a red mud calcified biomass leaching solution, comprising the following steps:

[0046] (1) The Bayer process red mud, potato powder, lime and circulating mother liquor are rapidly mixed in a slurry tank, the concentration of the circulating mother liquor is 350 g / L, the caustic ratio a k = 15, the mass ratio of the lime to the silicon dioxide in the Bayer process red mud is 2:1, the biomass accounts for 2.4% of the solid mass in the slurry, and the liquid-solid ratio ml:g of the slurry is 9:1;

[0047] (2) The reaction is carried out in an alkaline solution at 300°C, the reaction time is 120 min, the transformation process removes the alkali in the red mud and recovers part of the alumina, and at the same time, the magnetite in the red mud can be converted into magnetite. After the circulating mother liquor is treated by the calcified biomass, the residual hydrocarbons remain in the mother liquor;

[0048] (3) After the reaction, the slurry is settled in a settling tank, and then separated and washed to obtain a calcified biomass transformation residue and a separation liquid. The chemical content of alkali in the calcified biomass transformation residue is 0.8 wt%, the mass ratio of alumina to silicon dioxide is 0.86, and the separation liquid contains hydrocarbons;

[0049] (4) The pipe jet stirring reactor is used as the removal device, the oxygen volume content in the oxygen-rich air is 30%, the inlet pressure is 0.1 MPa, the separation liquid is reacted with the oxygen-rich air in the pipe jet stirring reactor, the reaction temperature is 50°C, the residence time is 60 min, the stirring speed is 200 rpm, the removal rate of the hydrocarbons in the separation liquid is 91.23%, and the hydrocarbons are converted into carbonates and water.

[0050] (5) After the reaction is completed, the reaction product is removed through the precision filtration device, the precision filtration device is a plate and frame filter, the removal rate of the solid content in the filtrate after the precision filtration is 93%. The filtrate after the precision filtration is returned to the alumina production system, and the filter residue is treated separately.

[0051] Example 5

[0052] A method for removing hydrocarbons from a red mud calcified biomass leaching solution, comprising the following steps:

[0053] (1) rapidly mixing Bayer red mud, corn starch, lime and circulating mother liquor in a slurry tank, the concentration of the circulating mother liquor being 280 g / L, the caustic ratio α k = 5, the mass ratio of lime to silicon dioxide in the Bayer red mud being 3:1; the biomass accounting for 0.4% of the solid mass in the mixed slurry; the liquid-solid ratio ml:g of the slurry being 8:1;

[0054] (2) reacting in an alkaline solution at 280°C for 90 min, the transformation process removing the alkali in the red mud and recovering part of the alumina, and at the same time converting the hematite in the red mud into magnetite, the circulating mother liquor being treated by the calcified biomass, and residual hydrocarbons remaining in the mother liquor;

[0055] (3) after the reaction, the slurry is settled in a settling tank, and then separated and washed to obtain calcified biomass transformation residue and a separation liquid; the chemical content of alkali in the calcified biomass transformation residue being 0.7 wt%, the mass ratio of alumina to silicon dioxide being 0.75, and the separation liquid containing hydrocarbons;

[0056] (4) using a tubular jet stirring reactor as a removal device, the oxygen volume content in the oxygen-enriched air used being 50%, the inlet pressure being 0.5 MPa, the separation liquid being reacted with the oxygen-enriched air in the tubular jet stirring reactor, the reaction temperature being 70°C, the residence time being 50 min, and the stirring speed being 200 rpm, the removal rate of hydrocarbons in the separation liquid being 95.23%, and the hydrocarbons being converted into carbonates and water;

[0057] (5) after the reaction is completed, the reaction products are removed by a precision filtration device, the precision filtration device being a plate and frame filter, the solid content removal rate of the refined liquid after precision filtration being 93%. The refined liquid after precision filtration is returned to the alumina production system, and the filter residue is treated separately.

[0058] Example 6

[0059] A method for removing hydrocarbons from a red mud calcified biomass leaching solution, comprising the following steps:

[0060] (1) rapidly mixing Bayer red mud, bagasse, lime and circulating mother liquor in a slurry tank, the concentration of the circulating mother liquor being 270 g / L, the caustic ratio α k = 6, the mass ratio of lime to silicon dioxide in the Bayer red mud being 2:1; the biomass accounting for 1.6% of the solid mass in the mixed slurry; the liquid-solid ratio ml:g of the slurry being 7:1;

[0061] (2) in the alkaline solution at 270℃ for 90min, the transformation process removes the alkali in the red mud and recovers part of the alumina, and at the same time, the hematite in the red mud can be converted into magnetite, and the residual hydrocarbons in the mother liquor are removed after the mother liquor is treated by the calcified biomass;

[0062] (3) after the reaction, the slurry is settled in a settling tank, then separated and washed to obtain the calcified biomass transformation residue and the separated liquid; the chemical content of alkali in the calcified biomass transformation residue is 0.7wt%, the mass ratio of alumina to silica is 0.82, and the separated liquid contains hydrocarbons;

[0063] (4) a tubular jet stirring reactor is used as the removal device, the oxygen volume content in the oxygen-enriched air used is 30%, the inlet pressure is 0.8Mpa, the separated liquid is reacted with the oxygen-enriched air in the tubular jet stirring reactor, the reaction temperature is 60℃, the residence time is 20min, and the stirring speed is 100rpm, the removal rate of the hydrocarbons in the separated liquid is 93.23%, and the hydrocarbons are converted into carbonates and water;

[0064] (5) after the reaction is completed, the reaction products are removed by a precision filtration device, the precision filtration device is a plate and frame filter, the solid content removal rate of the filtrate after precision filtration is 93%, and the filtrate after precision filtration returns to the alumina production system, and the filter residue is treated separately.

[0065] Example 7

[0066] A method for removing hydrocarbons from a red mud calcified biomass leaching solution, comprising the following steps:

[0067] (1) the Bayer process red mud, wheat bran, lime and recycled mother liquor are rapidly mixed in a slurry tank, the concentration of the recycled mother liquor is 290g / L, the caustic ratio α k = 8, the mass ratio of the lime to the silica in the Bayer process red mud is 1.5:1, the biomass accounts for 2.4% of the solid mass after mixing, and the liquid-solid ratio ml:g of the slurry is 9:1;

[0068] (2) in the alkaline solution at 260℃ for 50min, the transformation process removes the alkali in the red mud and recovers part of the alumina, and at the same time, the hematite in the red mud can be converted into magnetite, and the residual hydrocarbons in the mother liquor are removed after the mother liquor is treated by the calcified biomass;

[0069] (3) after the reaction, the slurry is settled in a settling tank, then separated and washed to obtain the calcified biomass transformation residue and the separated liquid; the chemical content of alkali in the calcified biomass transformation residue is 0.6wt%, the mass ratio of alumina to silica is 0.8, and the separated liquid contains hydrocarbons;

[0070] (4) using a tubular jet stirring reactor as a removal device, the oxygen volume content in the oxygen-rich air used is 100%, the inlet pressure is 1Mpa, the separation liquid is reacted with the oxygen-rich air in the tubular jet stirring reactor, the reaction temperature is 50℃, the residence time is 10min, the stirring speed is 200rpm, the removal rate of hydrocarbons in the separation liquid is 94.25%, and the hydrocarbons are converted into carbonates and water;

[0071] (5) after the reaction is completed, the reaction product is removed through a precision filtration device, the precision filtration device is a plate and frame filter, the solid content removal rate in the filtrate after precision filtration is 93%. The filtrate after precision filtration is returned to an alumina production system, and the filter residue is treated separately.

[0072] The above technical solutions describe the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification and improvement of the above technical solutions according to the technical essence of the present application, without departing from the content of the technical solutions of the present application, belongs to the protection scope of the technical solutions of the present application.

Claims

1. A method for removing hydrocarbons from a red mud calcified biomass leaching solution, characterized by comprising the following steps: (1) crushing and grinding the Bayer process red mud, biomass and calcareous compound, stirring and mixing with the circulating mother liquor or alkali liquor, and then performing a leaching reaction on the mixed slurry; (2) after the leaching reaction, performing sedimentation, separation and washing on the slurry to obtain a calcified biomass transformation residue and a separated liquid, wherein the separated liquid contains hydrocarbons; (3) reacting the separated liquid with oxygen-enriched air in a reactor, wherein the oxygen content of the oxygen-enriched air is 30% to 100%, the inlet pressure is 0.1 MPa to 1 MPa, the reaction temperature is 50 to 95°C, the residence time is 1 to 60 min, and the stirring speed is 50 to 200 rpm; the hydrocarbons in the separated liquid are removed and converted into carbonates and water, and the removal rate of the hydrocarbons in the separated liquid is greater than 90%; (4) removing the reaction products by a precision filtration device after the reaction is completed, wherein the precision filtration device is one of a plate and frame filter, a leaf filter, a rotary drum filter and a belt filter, the solid content removal rate of the filtrate after precision filtration is greater than 90%, and the filtrate is returned to an alumina production system, and the filter residue is treated separately. In the step (1), the mass ratio of lime to silicon dioxide in the Bayer process red mud is (1 to 4):1; the biomass accounts for 0.4% to 2.4% of the solid mass in the mixed slurry of the Bayer process red mud, biomass, calcareous compound and circulating mother liquor or alkali liquor; the ratio of the liquid volume to the solid mass of the slurry is (6 to 9):1; and the leaching temperature is 250°C to 300°C, and the leaching time is 30 to 120 min.

2. A method for removing hydrocarbons from a red mud calcified biomass solution according to claim 1, characterized by: The red mud in the step (1) is a solid waste produced by dissolution in the production of alumina by Bayer process, wherein the mass fraction of Fe2O3 is 10-50%, and the mass fraction of sodium alkali is 1-10%; the calcareous compound is one of calcium oxide, lime and carbide slag; the biomass is one or more of crude cassava powder, potato powder, corn starch, bagasse, wheat bran and rice straw; the circulating mother liquor or lye is a circulating mother liquor in the Bayer process or a prepared lye, the alkali concentration in the prepared lye and the circulating mother liquor is 200-350 g / L, and the caustic ratio α k =2-15.

3. A method for removing hydrocarbons from a red mud calcified biomass solution according to claim 2, characterized in that: In the step (2), the chemical content of alkali in the calcified biomass transformation residue is less than 1 wt%, and the mass ratio of alumina to silicon dioxide is less than 1.

4. A method for removing hydrocarbons from a red mud calcified biomass solution according to claim 1, characterized by: The device is a tubular jet stirring reactor for reacting the hydrocarbons in the red mud calcified biomass leaching solution with oxygen-enriched air, which comprises a horizontal reaction cavity, a stirring shaft arranged in the middle of the reaction cavity, a jet stirring paddle arranged on the stirring shaft, and a plurality of air holes arranged on the jet stirring paddle, wherein the stirring shaft and the jet stirring paddle are integrally arranged, the air holes have a diameter of 1 to 4 microns, the stirring shaft has a hollow structure and is connected to the jet stirring paddle, one end of the stirring shaft is connected to the output shaft of a stirring motor outside the reaction cavity, the other end of the stirring shaft is arranged on the side wall of the reaction cavity and connected to a high-pressure gas circuit, the upper part of the reaction cavity is respectively provided with a feed inlet and an air outlet, and the lower part of the reaction cavity is provided with a discharge outlet.

5. A device for removing hydrocarbons from a red mud calcified biomass leachate, for use in the method of removing hydrocarbons from a red mud calcified biomass leachate according to any one of claims 1 to 4, characterised in that: ​

Images