Device and method for degrading organic impurities in sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclonic flow

Abstract

The invention discloses a device and method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones. The device relates to the technical field of alumina production and comprises an ozone nanobubble generating mechanism and a reaction mechanism. The ozone nanobubble generating mechanism comprises an ozone generator and a nanobubble generator. The ozone generator can convert oxygen into ozone gas, and the nanobubble generator can form ozone nanobubbles from the ozone generator. The reaction mechanism comprises a cyclone mixing reactor and an ultrasonic generator. The liquid inlet of the cyclone mixing reactor is used to introduce the sodium aluminate solution, and the cyclone mixing reactor can form a cyclone in the sodium aluminate solution and mix it with the ozone nanobubbles. The ultrasonic generator is arranged on the cyclone mixing reactor and can irradiate the cyclone mixing reactor with ultrasonic waves, so that the ozone nanobubbles degrade the organic impurities in the sodium aluminate solution under the ultrasonic radiation.

Description

Technical Field

[0001] The invention relates to the technical field of alumina production, and in particular to a device and method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones. Background Art

[0002] The aluminum industry and electrolytic aluminum production play a decisive role in the demand for alumina. Bauxite, the primary raw material for aluminum production, undergoes intermediate refining in the Bayer process to produce alumina, which is then electrolytically produced into primary aluminum. Currently, over 95% of global Al2O3 production is produced using the Bayer process. During this process, large amounts of organic matter are introduced from bauxite and other flocculants and additives. These organic matter accumulates during the Bayer process, leading to reduced alumina product quality, finer particle size, and low current efficiency.

[0003] Traditional processes for degrading organic impurities in sodium aluminate solution mainly include bauxite roasting, mother liquor roasting, adsorption, crystallization, lime causticization, and wet oxidation. Among them, the roasting method has high energy consumption and production application costs; the adsorption method can only remove certain specific organic matter and reduce the critical concentration of sodium oxalate, but has no removal effect on sodium oxalate itself; the crystallization method is only suitable for sodium oxalate removal; the lime causticization method usually causes the loss of aluminum oxide and is therefore less used; the wet oxidation method has the advantages of clean products, less aluminum loss, and efficient reduction of organic impurity concentrations. For example, Chinese patent documents CN114832411A, CN113428883A, CN106044811A and foreign patents Patents such as US4668486A have successively proposed strategies for removing organic impurities from sodium aluminate solution by wet oxidation, which usually uses air or oxygen as an oxidant in the liquid phase under high temperature (150-350°C) and high pressure (5-20MPa) operating conditions. For example, Chinese patent document CN108046301A relates to a method for synchronous oxidation to eliminate sulfur and organic matter in bauxite slurry. The heated slurry and high-pressure oxygen are introduced into a tubular reactor for oxidation reaction. The S in the slurry liquid phase is 2- After oxidation of the organic matter, the slurry exiting the tubular reactor enters the Bayer process's holding tank, autoclave, or self-evaporator. However, existing wet oxidation processes suffer from harsh reaction conditions (high temperature and high pressure), the presence of non-condensable gases (such as hydrogen) in the reaction products, which can easily cause explosions and pose serious safety risks. Therefore, a low-temperature, atmospheric-pressure oxidation method is needed to degrade organic impurities in sodium aluminate solutions.

[0004] Ozone oxidation, as a typical low-temperature, atmospheric-pressure oxidation technology, has significant application prospects for the degradation of organic impurities in sodium aluminate solutions. However, there is currently very little research in this field. Miguel Antonio Soplin Pastor and others from the University of São Paulo, Brazil, investigated the effects of ozone systems and ozone-hydrogen peroxide combined systems on the removal of organic matter from Bayer liquor. Because they only used micron ozone bubbles, the highest organic carbon removal rate was only 19%. Due to the rapid disappearance of the internal gas, micron ozone bubbles easily burst in water; due to their large specific surface area, micron ozone bubbles quickly escape the liquid surface and have a short residence time, resulting in a small contact area between them and the target organic matter and low mass transfer efficiency.

[0005] It can be seen that the current wet oxidation process faces technical bottlenecks such as harsh reaction conditions (high temperature and high pressure), non-condensable gases (such as hydrogen) in the reaction products that are prone to explosion, serious safety hazards, short residence time of micron ozone bubbles and low mass transfer efficiency. Providing a new method for degrading organic impurities in sodium aluminate solution is an urgent problem to be solved. Summary of the Invention

[0006] The present invention aims to provide a device and method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow, so as to solve the problems existing in the above-mentioned related technologies. The device can efficiently degrade organic impurities in the sodium aluminate solution, and has the advantages of mild reaction conditions, safe operation, no secondary pollution, and green and high efficiency.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a device for degrading organic impurities in a sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclones, comprising an ozone nanobubble generating mechanism and a reaction mechanism. The ozone nanobubble generating mechanism comprises an ozone generator and a nanobubble generator. The air inlet of the ozone generator is used to introduce oxygen, and the ozone generator can convert the oxygen into ozone gas. The air outlet of the ozone generator is used to pass the ozone gas, and the air outlet of the ozone generator is connected to the air inlet of the nanobubble generator. The nanobubble generator can form ozone nanobubbles from the ozone gas, and the air outlet of the nanobubble generator is used to pass the ozone gas. The ozone nanobubbles are produced; the reaction mechanism includes a cyclone mixing reactor and an ultrasonic generator, the air inlet of the cyclone mixing reactor is connected to the air outlet of the nanobubble generator, the liquid inlet of the cyclone mixing reactor is used to introduce a sodium aluminate solution, and the cyclone mixing reactor can form a cyclone of the sodium aluminate solution and mix it with the ozone nanobubbles. The ultrasonic generator is provided on the cyclone mixing reactor and can irradiate the inside of the cyclone mixing reactor with ultrasonic waves, so that the ozone nanobubbles degrade organic impurities in the sodium aluminate solution under the ultrasonic radiation.

[0009] Preferably, the swirl mixing reactor includes a reaction tank and a circulation pump, the upper part of the reaction tank is a cylindrical structure, and the lower part of the reaction tank is an inverted cone structure; the upper inner wall of the reaction tank is provided with swirl blades, the swirl blades are arc-shaped blades, and a plurality of swirl blades are arranged obliquely downward from the outside to the inside, and all of the swirl blades are evenly distributed on the upper inner wall of the reaction tank along the circumferential direction; the lower inner wall of the reaction tank is provided with a swirl channel, the swirl channel is a groove structure, and the swirl channel is spirally coiled on the lower inner wall of the reaction tank;

[0010] The upper part of the reaction tank is provided with a sodium aluminate solution inlet and a circulation port, and the lower part of the reaction tank is provided with an ozone nanobubble inlet and a drain port, wherein the sodium aluminate solution inlet is used to introduce the sodium aluminate solution, the ozone nanobubble inlet is connected to the air outlet of the nanobubble generator, and the drain port is connected to the circulation port through a circulation pipeline. The circulation pump is provided on the circulation pipeline, and a drain pipe is further connected to the circulation pipeline at a position between the drain port and the circulation pump, and a drain valve is provided on the drain pipe.

[0011] Preferably, nanopores are distributed on the surface of the swirl blade and the inner wall of the swirl channel.

[0012] Preferably, the ultrasonic generator includes a horn and a transducer, the horn is passed through the reaction tank, and the transducer is connected to the horn.

[0013] Preferably, the nanobubble generator includes a nanobubble generating chamber, a cutting assembly and a motor, the nanobubble generating chamber is provided with an ozone gas inlet and an ozone nanobubble outlet, the ozone gas inlet is communicated with the gas outlet of the ozone generator, and the ozone nanobubble outlet is communicated with the gas inlet of the cyclone mixing reactor; the cutting assembly is arranged in the nanobubble generating chamber, the cutting assembly includes a diaphragm and a rotating shaft, the surface of the diaphragm is densely covered with nanopores, and the diaphragm is provided with a plurality of nanopores, all of the diaphragms are evenly penetrated on the rotating shaft, the rotating shaft is connected to the output end of the motor, and the motor can drive the rotating shaft to rotate, so as to drive the diaphragm to rotate and cut the ozone gas in the nanobubble generating chamber, so that the ozone gas forms the ozone nanobubbles.

[0014] Preferably, the ozone generator includes a honeycomb ozone discharge chamber and a high-voltage inverter power supply, the honeycomb ozone discharge chamber is provided with an oxygen inlet and an ozone gas outlet, the oxygen inlet is used to introduce the oxygen, the ozone gas outlet is connected to the ozone gas inlet of the nanobubble generating chamber, and the honeycomb ozone discharge chamber is connected to the high-voltage inverter power supply to perform high-voltage discharge on the oxygen to generate the ozone gas.

[0015] Preferably, the device for degrading organic impurities in sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclones further includes a tail gas treatment mechanism, wherein the gas outlet of the cyclone mixing reactor is used to discharge the ozone tail gas, and the gas outlet of the cyclone mixing reactor is connected to the gas inlet of the tail gas treatment mechanism, the tail gas treatment mechanism is capable of purifying the ozone tail gas, and the gas outlet of the tail gas treatment mechanism is used to discharge the purified ozone tail gas.

[0016] Preferably, the exhaust gas treatment mechanism includes an exhaust gas treatment chamber, which is provided with an ozone exhaust gas inlet and an exhaust port. The ozone exhaust gas inlet is located at the bottom of the exhaust gas treatment chamber and is connected to the exhaust port of the cyclone mixing reactor. The exhaust gas treatment chamber is provided with a catalytic ultraviolet irradiation layer, a chemical absorption layer and an activated carbon adsorption layer from bottom to top. The exhaust port is located at the top of the exhaust gas treatment chamber, and the exhaust port is used to discharge the purified ozone exhaust.

[0017] The present invention also provides a method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones. The method comprises the following steps:

[0018] Step 1: introducing the oxygen into the ozone generator, and converting the oxygen into the ozone gas through the ozone generator;

[0019] Step 2, forming the ozone nanobubbles from the ozone generator through the nanobubble generator;

[0020] Step 3: The sodium aluminate solution is introduced into the cyclone mixing reactor, the sodium aluminate solution is cycloned by the cyclone mixing reactor, and mixed with the ozone nanobubbles from the nanobubble generator. At the same time, the ozone nanobubbles are irradiated by the ultrasonic generator to degrade organic impurities in the sodium aluminate solution until the target is reached and the ozone oxidation reaction is stopped.

[0021] Preferably, the organic carbon content in the sodium aluminate solution is 1 to 15 g / L;

[0022] The ratio of the mass of the ozone gas to the volume of the sodium aluminate solution is (1-20) g:1 L;

[0023] The frequency of ultrasound is 20 to 40 kHz;

[0024] The ratio of ultrasonic power to the volume of the sodium aluminate solution is (0.02-0.2) kW:1 L;

[0025] Ultrasound was intermittent, with a working time of 0.1 to 9.9 seconds and an interval of 0.1 to 1 second between two adjacent ultrasounds.

[0026] The existence time of the ozone nanobubbles is 10,000 to 30,000 minutes;

[0027] The density of the ozone nanobubbles is 0.1 to 10×10 8 / mL;

[0028] The diameter of the ozone nanobubbles is 10 to 200 nm;

[0029] The dissolved amount of the ozone nanobubbles is 1 to 10 mg / L;

[0030] The zeta potential of the ozone nanobubbles is -30 to -60 mV;

[0031] The volume mass transfer coefficient of the ozone nanobubbles is 1 to 5 min -1 ;

[0032] The temperature of ultrasound-assisted ozone nanobubble oxidation reaction is 25-80°C, and the reaction time is 10 minutes to 3 hours;

[0033] In the step three, the ozone tail gas in the cyclone mixing reactor is introduced into the tail gas treatment system, and is purified by passing through a catalytic ultraviolet irradiation layer using ultraviolet light with a wavelength of 200 to 400 nm, a chemical absorption layer using a Na2S2O3 solution with a molar concentration of 0.1 to 1 mol / L, and an activated carbon adsorption layer using honeycomb activated carbon with a pore size of 0.1 to 3 mm.

[0034] Compared with the related art, the present invention has achieved the following technical effects:

[0035] The present invention provides a device for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones. The device comprises an ozone nanobubble generating mechanism and a reaction mechanism, wherein the ozone nanobubble generating mechanism comprises an ozone generator and a nanobubble generator, and the reaction mechanism comprises a cyclone mixing reactor and an ultrasonic generator. When in use, oxygen is introduced into the ozone generator, the ozone generator converts the oxygen into ozone gas, and the nanobubble generator forms ozone nanobubbles from the ozone generator. Then, a sodium aluminate solution is introduced into the cyclone mixing reactor, the cyclone mixing reactor forms a cyclone in the sodium aluminate solution, and the cyclone mixes the sodium aluminate solution with the ozone nanobubbles from the nanobubble generator. Simultaneously, the ultrasonic generator causes the ozone nanobubbles to degrade the organic impurities in the sodium aluminate solution under ultrasonic radiation until the ozone oxidation reaction is stopped after the target is achieved.

[0036] Thus, the present invention, by providing an ultrasonic generator, applies ultrasonic technology to change the physical and chemical properties of the treated medium, improves the chemical reaction conditions, accelerates the chemical reaction rate, and thus achieves efficient degradation of key organic impurities in the sodium aluminate solution; the present invention, by providing an ozone generator and a nanobubble generator, applies ozone nanobubble technology to significantly enhance the mass transfer efficiency at the gas-liquid interface, stimulates a large number of active free radicals with extremely strong oxidizing properties, and thus achieves efficient degradation of organic impurities; the present invention, by providing a cyclonic mixing reactor, causes the sodium aluminate solution to form a cyclonic flow, thereby effectively accelerating the mixing efficiency and reaction rate between the ozone nanobubbles and the organic matter in the sodium aluminate solution. Therefore, compared with the traditional organic matter removal process in the alumina industry, the present device has the advantages of mild reaction conditions, safe operation, no secondary pollution, green and efficient, etc. The large-scale use of the present device in the alumina industry is expected to reduce energy consumption by about 49%, which has important scientific value and practical significance for the high-value utilization and sustainable development of the alumina industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 Schematic diagram of a device for degrading organic impurities in a sodium aluminate solution using ozone nanobubbles coupled with ultrasonic cyclonic flow, provided in Example 1 of the present invention;

[0039] Figure 2 A schematic diagram of the internal structure of the reaction tank provided in Example 1 of the present invention (top view);

[0040] Figure 3 A schematic diagram of a process flow of a method for degrading organic impurities in a sodium aluminate solution using ozone nanobubbles coupled with ultrasonic cyclonic flow, provided in Example 2 of the present invention;

[0041] Figure 4 This is a comparison chart of the existence time of ozone bubbles in the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0042] Figure 5 This is a comparison chart of the bubble densities of the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0043] Figure 6 This is a comparison chart of the ozone bubble diameters of the ozone microbubble system, the ozone nanobubble system, and the ultrasonically enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0044] Figure 7 This is a comparison chart of the ozone bubble dissolution amounts of the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0045] Figure 8 This is a comparison chart of the ozone bubble Zeta potential of the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0046] Figure 9 This is a comparison chart of the ozone bubble volume mass transfer coefficients of the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0047] Figure 10 This is a comparison chart of the organic matter oxidation rates of the ozone microbubble system, the ozone nanobubble system, and the ultrasound-enhanced ozone nanobubble system in Application Example 1 of the present invention.

[0048] In the figure: 1-reaction tank, 101-sodium aluminate solution inlet, 102-circulation port, 103-ozone nanobubble inlet, 104-drain port, 2-circulation pump, 3-swirl blade, 4-swirl channel, 5-nanopore, 6-circulation pipeline, 7-drain pipe, 8-drain valve, 9-amplitude rod, 10-transducer, 11-first cooling fan, 12-nanobubble generating chamber, 1201-ozone gas inlet, 1202-ozone nanobubble outlet, 13-motor, 14-diaphragm, 15-honeycomb ozone discharge chamber, 1501-oxygen inlet, 1502-ozone gas outlet, 16-high-voltage inverter power supply, 17-oxygen cylinder, 18-second cooling fan, 19-exhaust treatment chamber, 1901-ozone exhaust gas inlet, 1902-exhaust port, 20-catalytic ultraviolet irradiation layer, 21-chemical absorption layer, 22-activated carbon adsorption layer. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] The present invention aims to provide a device and method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones, so as to solve the problems existing in the related art. The device can efficiently degrade organic impurities in the sodium aluminate solution, and has the advantages of mild reaction conditions, safe operation, no secondary pollution, and green and high efficiency.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] like Figure 1-Figure 2As shown, this embodiment provides an ozone nanobubble coupled ultrasonic cyclone degrading organic impurities in a sodium aluminate solution, comprising an ozone nanobubble generating mechanism and a reaction mechanism, wherein the ozone nanobubble generating mechanism comprises an ozone generator and a nanobubble generator, wherein the air inlet of the ozone generator is used to introduce oxygen, the ozone generator can convert oxygen into ozone gas, the air outlet of the ozone generator is used to pass the ozone gas, and the air outlet of the ozone generator is connected to the air inlet of the nanobubble generator, the nanobubble generator can form ozone nanobubbles from the ozone gas, and the outlet of the nanobubble generator is connected to the air inlet of the nanobubble generator. The air port is used to discharge ozone nanobubbles; the reaction mechanism includes a cyclone mixing reactor and an ultrasonic generator, the air inlet of the cyclone mixing reactor is connected to the air outlet of the nanobubble generator, the liquid inlet of the cyclone mixing reactor is used to introduce the sodium aluminate solution, and the cyclone mixing reactor can form a cyclone of the sodium aluminate solution and mix it with the ozone nanobubbles. The ultrasonic generator is arranged on the cyclone mixing reactor, and the ultrasonic generator can irradiate the cyclone mixing reactor with ultrasonic waves, so that the ozone nanobubbles degrade organic impurities in the sodium aluminate solution under the ultrasonic radiation state.

[0054] In this embodiment, the swirl mixing reactor includes a reaction tank 1 and a circulation pump 2. The upper part of the reaction tank 1 is a cylindrical structure, and the lower part of the reaction tank 1 is an inverted cone structure; the upper inner wall of the reaction tank 1 is provided with a swirl blade 3, and the swirl blade 3 is provided with a plurality of swirl blades, all of which are evenly distributed on the upper inner wall of the reaction tank 1 along the circumferential direction; specifically, the swirl blade 3 in this embodiment is an arc-shaped blade, and the swirl blade 3 is arranged downwardly from the outside to the inside; the lower inner wall of the reaction tank 1 is etched with a swirl channel 4, The swirl channel 4 is a groove structure, and the swirl channel 4 is spirally coiled on the lower inner wall of the reaction tank 1. When the liquid entering the reaction tank 1 flows through the swirl blades 3 and the swirl channel 4, it will be hindered. Under the guiding action of the swirl blades 3 and the swirl channel 4, a swirl effect is generated; further, the surface of the swirl blades 3 and the inner wall of the swirl channel 4 in this embodiment are evenly distributed with nanopores 5, which can significantly increase the turbulent vortex in the impact zone in the reaction tank 1, enhance the turbulence intensity and radial pressure gradient.

[0055] In this embodiment, a sodium aluminate solution inlet 101 and a circulation port 102 are provided at the upper part of the reaction tank 1, and an ozone nanobubble inlet 103 and a drain port 104 are provided at the lower part of the reaction tank 1, wherein the sodium aluminate solution inlet 101 is used to introduce the sodium aluminate solution, the ozone nanobubble inlet 103 is connected to the air outlet of the nanobubble generator, and the drain port 104 is connected to the circulation port 102 through the circulation pipeline 6. The circulation pump 2 is provided on the circulation pipeline 6, and a drain pipe 7 is also connected to the position on the circulation pipeline 6 between the drain port 104 and the circulation pump 2, and a drain valve 8 is provided on the drain pipe 7.

[0056] In this embodiment, the ultrasonic generator includes a variable amplitude rod 9 and a transducer 10. The variable amplitude rod 9 is inserted into the reaction tank 1, and the transducer 10 is connected to the variable amplitude rod 9. Specifically, the transducer 10 and the variable amplitude rod 9 in this embodiment are connected by a double-headed stud. The electrical signal is converted into a mechanical vibration signal by the transducer 10, and then the mechanical vibration signal generated by the transducer 10 is amplified by the variable amplitude rod 9, thereby enhancing the energy concentration of the ultrasonic wave, improving the vibration efficiency, and optimizing the ultrasonic strengthening effect. The ultrasonic generator in this embodiment also includes a first cooling fan 11, which is used to cool the transducer 10.

[0057] In this embodiment, the nanobubble generator includes a nanobubble generating chamber 12, a cutting assembly and a motor 13. The nanobubble generating chamber 12 is provided with an ozone gas inlet 1201 and an ozone nanobubble outlet 1202. The ozone gas inlet 1201 is connected to the air outlet of the ozone generator, and the ozone nanobubble outlet 1202 is connected to the air inlet of the cyclone mixing reactor; the cutting assembly is arranged in the nanobubble generating chamber 12, and the cutting assembly includes a diaphragm 14 and a rotating shaft. The surface of the diaphragm 14 is densely covered with nanopores, and the diaphragm 14 is provided with a plurality of nanopores. All diaphragms 14 are evenly penetrated on the rotating shaft. The rotating shaft is connected to the output end of the motor 13. The motor 13 can drive the rotating shaft to rotate, so as to drive the diaphragm 14 to rotate and cut the ozone gas in the nanobubble generating chamber 12, so that the ozone gas forms ozone nanobubbles, that is, through the high-speed rotation cutting of the diaphragm 14, the ozone gas forms a large number of fine ozone nanobubbles, ensuring the uniform distribution and efficient generation of ozone nanobubbles.

[0058] In this embodiment, the ozone generator includes a honeycomb ozone discharge chamber 15 and a high-voltage inverter power supply 16. The honeycomb ozone discharge chamber 15 is provided with an oxygen inlet 1501 and an ozone gas outlet 1502. The oxygen inlet 1501 is used to introduce oxygen. The ozone gas outlet 1502 is connected to the ozone gas inlet 1201 of the nanobubble generating chamber 12, and the honeycomb ozone discharge chamber 15 is connected to the high-voltage inverter power supply 16 to perform high-voltage discharge on oxygen to generate ozone gas. Specifically, the oxygen source in this embodiment is an oxygen cylinder 17. The oxygen outlet of the oxygen cylinder 17 is connected to the oxygen inlet 1501 of the honeycomb ozone discharge chamber 15 through an oxygen delivery pipeline, and a gas flow meter and a valve are provided on the oxygen delivery pipeline. The ozone generator in this embodiment also includes a second cooling fan 18, which is used to cool the honeycomb ozone discharge chamber 15.

[0059] In this embodiment, the device for degrading organic impurities in sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclones also includes an exhaust gas treatment mechanism. The gas outlet of the cyclone mixing reactor is used to discharge the ozone exhaust gas, and the gas outlet of the cyclone mixing reactor is connected to the air inlet of the exhaust gas treatment mechanism. The exhaust gas treatment mechanism can purify the ozone exhaust gas, and the gas outlet of the exhaust gas treatment mechanism is used to discharge the purified ozone exhaust gas.

[0060] Furthermore, the exhaust gas treatment mechanism includes an exhaust gas treatment chamber 19, which is provided with an ozone exhaust gas inlet 1901 and an exhaust port 1902. The ozone exhaust gas inlet 1901 is located at the bottom of the exhaust gas treatment chamber 19 and is connected to the exhaust port of the cyclone mixing reactor. The exhaust gas treatment chamber 19 is provided with a catalytic ultraviolet irradiation layer 20, a chemical absorption layer 21 and an activated carbon adsorption layer 22 from bottom to top. The exhaust port 1902 is located at the top of the exhaust gas treatment chamber 19, and the exhaust port 1902 is used to discharge the purified ozone exhaust gas.

[0061] The working process of the device provided in this embodiment for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow is as follows:

[0062] Oxygen generates ozone through high-voltage discharge in the ozone generator; ozone gas is passed into the nanobubble generator to form a large number of tiny ozone nanobubbles; ozone nanobubbles and a sodium aluminate solution containing a large amount of organic impurities are passed into a cyclonic mixing reactor, and an ultrasonic generator is used to further enhance the oxidation and degradation process of organic matter, rapidly catalyzing oxidation until the target is reached and then stopping the reaction; ozone tail gas is absorbed by the tail gas treatment mechanism; the sodium aluminate solution after the organic impurities are purified returns to the dissolution stage for continued recycling.

[0063] Example 2

[0064] like Figure 3 As shown, this embodiment provides a method for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones. The method employing the above-mentioned device for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones comprises the following steps:

[0065] Step 1: introducing oxygen into an ozone generator to convert the oxygen into ozone gas;

[0066] Step 2: Using a nanobubble generator to generate ozone nanobubbles from the ozone gas in the ozone generator;

[0067] Step 3: The sodium aluminate solution is introduced into a cyclone mixing reactor, the sodium aluminate solution is cycloned by the cyclone mixing reactor, and mixed with the ozone nanobubbles from the nanobubble generator. At the same time, the ozone nanobubbles are irradiated by the ultrasonic generator to degrade the organic impurities in the sodium aluminate solution until the target is reached and the ozone oxidation reaction is stopped.

[0068] In this embodiment, the content of organic carbon in the sodium aluminate solution is 1-15 g / L; the ratio of the mass of ozone gas to the volume of the sodium aluminate solution is (1-20) g:1 L;

[0069] The frequency of ultrasound is 20 to 40 kHz; the ratio of ultrasound power to the volume of sodium aluminate solution is (0.02 to 0.2) kW:1 L; ultrasound is intermittent, the working time of ultrasound is 0.1 to 9.9 s, and the interval between two adjacent ultrasounds is 0.1 to 1 s;

[0070] The existence time of ozone nanobubbles is 10000~30000min; the density of ozone nanobubbles is 0.1~10×10 8 The diameter of ozone nanobubbles is 10-200 nm; the solubility of ozone nanobubbles is 1-10 mg / L; the Zeta potential of ozone nanobubbles is -30--60 mV; the volume mass transfer coefficient of ozone nanobubbles is 1-5 min -1 ;

[0071] The temperature of ultrasound-assisted ozone nanobubble oxidation reaction is 25-80°C, and the reaction time is 10 minutes to 3 hours;

[0072] In step three, the ozone tail gas in the cyclone mixing reactor is introduced into the tail gas treatment system, and is purified by passing through a catalytic ultraviolet irradiation layer using ultraviolet light with a wavelength of 200 to 400 nm, a chemical absorption layer using a Na2S2O3 solution with a molar concentration of 0.1 to 1 mol / L, and an activated carbon adsorption layer using honeycomb activated carbon with a pore size of 0.1 to 3 mm.

[0073] The following are eight application examples of the present invention (i.e., ultrasonically enhanced ozone nanobubble system):

[0074] Application Example 1

[0075] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×107 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature is 55°C, the reaction time is 1.5h, and the ozone tail gas is treated in three layers continuously, wherein the activated carbon adsorption layer 22 adopts honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 adopts Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 adopts ultraviolet light with a wavelength of 254nm.

[0076] Figures 4-10 This is a comparison chart of the ozone microbubble system, ozone nanobubble system, and ultrasound-enhanced ozone nanobubble system in Application Example 1.

[0077] Compared with the existing ozone microbubble system, the ultrasound-assisted nanobubble technology in Application Example 1 can significantly improve various indicators, such as extending the existence time of ozone bubbles by 960 times, increasing the ozone bubble density by 120 times, reducing the ozone bubble diameter by 210 times, increasing the ozone bubble solubility by 26 times, increasing the ozone bubble Zeta potential by 4 times, increasing the ozone bubble volume mass transfer coefficient by 18 times, and ultimately increasing the organic matter oxidation rate by 3 times.

[0078] The results of organic matter degradation are shown in Table 1. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

[0079] Table 1 Comparison of the degradation effects of two systems in application example 1 on organic impurities in sodium aluminate solution

[0080]

[0081] Application Example 2

[0082] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the ozone dosage is different.

[0083] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 20 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature is 55°C, the reaction time is 1.5h, and the ozone tail gas is treated in three layers continuously, wherein the activated carbon adsorption layer 22 adopts honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 adopts Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 adopts ultraviolet light with a wavelength of 254nm.

[0084] The results of organic matter degradation are shown in Table 2. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

[0085] Table 2 Comparison of the degradation effects of two systems in application example 2 on organic impurities in sodium aluminate solution

[0086]

[0087] Application Example 3

[0088] The process parameters used in this application example are the same as those in application example 1, but the raw materials are different.

[0089] Specific reaction parameters: the organic impurity content in the sodium aluminate solution to be treated is 15 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature is 55°C, the reaction time is 1.5h, and the ozone tail gas is treated in three layers continuously, wherein the activated carbon adsorption layer 22 adopts honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 adopts Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 adopts ultraviolet light with a wavelength of 254nm.

[0090] The results of organic matter degradation are shown in Table 3. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

[0091] Table 3 Comparison of the degradation effects of two systems in application example 3 on organic impurities in sodium aluminate solution

[0092]

[0093] Application Example 4

[0094] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the ultrasonic power density is different.

[0095] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.2 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature was 55°C, the reaction time was 1.5 hours, and ozone tail gas was treated using three consecutive layers: activated carbon adsorption layer 22 utilized honeycomb activated carbon with a pore size of 0.5 mm, chemical absorption layer 21 employed a Na₂S₂O₃ solution with a molar concentration of 0.5 mol / L, and catalytic ultraviolet irradiation layer 20 utilized ultraviolet light with a wavelength of 254 nm. The organic matter degradation results are shown in Table 4. For the ultrasound-enhanced ozone nanobubble system, the organic impurity degradation efficiency significantly increased with increasing ultrasonic power density.

[0096] Table 4 Comparison of the degradation effects of organic impurities in sodium aluminate solution at different power densities in the ultrasonically enhanced ozone nanobubble system in Application Example 4

[0097]

[0098] Application Example 5

[0099] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the reaction temperature is different (the reaction temperature is controlled by a constant temperature water bath).

[0100] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature was 25°C, the reaction time was 1.5 hours, and ozone tail gas was treated using three consecutive layers: activated carbon adsorption layer 22 utilized honeycomb activated carbon with a pore size of 0.5 mm, chemical absorption layer 21 employed a Na₂S₂O₃ solution with a molar concentration of 0.5 mol / L, and catalytic ultraviolet irradiation layer 20 utilized ultraviolet light with a wavelength of 254 nm. The organic matter degradation results are shown in Table 5. Compared to the ozone microbubble system, the ultrasonically enhanced ozone nanobubble system significantly improved the degradation efficiency of organic impurities.

[0101] Table 5 Comparison of the degradation effects of two systems in application example 5 on organic impurities in sodium aluminate solution

[0102]

[0103] Application Example 6

[0104] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the reaction time is different.

[0105] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature was 55°C, the reaction time was 3 hours, and ozone tail gas was treated using three consecutive layers: activated carbon adsorption layer 22 utilized honeycomb activated carbon with a pore size of 0.5 mm, chemical absorption layer 21 employed a Na₂S₂O₃ solution with a molar concentration of 0.5 mol / L, and catalytic ultraviolet irradiation layer 20 utilized ultraviolet light with a wavelength of 254 nm. The organic matter degradation results are shown in Table 6. Compared to the ozone microbubble system, the ultrasonically enhanced ozone nanobubble system significantly improved the degradation efficiency of organic impurities.

[0106] Table 6 Comparison of the degradation effects of two systems in application example 6 on organic impurities in sodium aluminate solution

[0107]

[0108] Application Example 7

[0109] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the ultrasonic frequency is different.

[0110] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 40 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 28800 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 105nm, the solubility of ozone nanobubbles is 9.62mg / L, the Zeta potential of ozone nanobubbles is -57mV, and the volume mass transfer coefficient of ozone nanobubbles is 3.5min -1 The reaction temperature was 55°C, the reaction time was 1.5 hours, and ozone tail gas was treated using three consecutive layers: activated carbon adsorption layer 22 utilized honeycomb activated carbon with a pore size of 0.5 mm, chemical absorption layer 21 employed a Na₂S₂O₃ solution with a molar concentration of 0.5 mol / L, and catalytic ultraviolet irradiation layer 20 utilized ultraviolet light with a wavelength of 254 nm. The organic matter degradation results are shown in Table 7. For the ultrasound-enhanced ozone nanobubble system, the organic impurity degradation efficiency decreased with increasing ultrasonic frequency.

[0111] Table 7 Comparison of the degradation effects of different power frequencies on organic impurities in sodium aluminate solution in the ultrasound-enhanced ozone nanobubble system in Application Example 7

[0112]

[0113] Application Example 8

[0114] The raw materials and other process parameters used in this application example are the same as those in application example 1, but the size of the ozone nanobubbles is different (the size of the ozone nanobubbles is adjusted by controlling the speed of the motor 13 and the size of the nanopores densely distributed on the diaphragm 14).

[0115] Specific reaction parameters are as follows: the organic impurity content in the sodium aluminate solution to be treated is 10.89 g / L, the ratio of the mass of ozone added to the volume of the sodium aluminate solution is 13 g:1 L, the frequency of ultrasound is 25 kHz, the ratio of ultrasound power to the volume of the sodium aluminate solution is 0.1 kW:1 L, the working time of ultrasound is 9 s, the interval between two adjacent ultrasounds is 1 s, the existence time of ozone nanobubbles is 30,000 min, and the density of ozone nanobubbles is 8×10 7 / mL, the diameter of ozone nanobubbles is 40nm, the solubility of ozone nanobubbles is 9.32mg / L, the Zeta potential of ozone nanobubbles is -60mV, and the volume mass transfer coefficient of ozone nanobubbles is 4.2min -1 The reaction temperature was 55°C, the reaction time was 1.5 hours, and ozone tail gas was treated using three consecutive layers: activated carbon adsorption layer 22 utilized honeycomb activated carbon with a pore size of 0.5 mm, chemical absorption layer 21 employed a Na₂S₂O₃ solution with a molar concentration of 0.5 mol / L, and catalytic ultraviolet irradiation layer 20 utilized ultraviolet light with a wavelength of 254 nm. The organic matter degradation results are shown in Table 8. Compared to the ozone microbubble system, the ultrasonically enhanced ozone nanobubble system significantly improved the degradation efficiency of organic impurities.

[0116] Table 8 Comparison of the degradation effects of two systems in application example 8 on organic impurities in sodium aluminate solution

[0117]

[0118] The above experiments demonstrate that the use of the present invention (ultrasound-enhanced ozone nanobubble system) to degrade key organic impurities in sodium aluminate solution significantly improves organic degradation, making the purified sodium aluminate solution more suitable for alumina production systems. This invention reduces the cost and improves the efficiency of degradation, making it easier to commercialize.

[0119] It should be noted that the principle of the present invention can be analyzed from the following four aspects:

[0120] (1) Power ultrasound technology, which is hailed as "industrial MSG" by the American industry, is a high-tech technology based on multiple disciplines such as physics, mechanical vibration, and materials. When ultrasound acts on a solution, it will produce ① a perturbation effect, that is, the action of ultrasound causes the molecules and ions in the solution to deviate from their original state, increase the probability of collision, and have a certain impact on the dynamic equilibrium of the solution; ② a turbulent effect, that is, the disturbance caused by the cavitation bubbles generated by ultrasound to the solution after they break, accelerating the irregular movement and collision of particles in the solution; ③ an interfacial effect, that is, the changes in the solution caused by the accumulation of bubbles in the solution, which can destroy the outer layer of mineral particles, form cavities, accelerate the migration and transformation of substances, and increase the metal leaching rate; ④ an energy-gathering effect, that is, the generation of a high-pressure impact flow in the solution that can break the intermolecular force, change the metastable state generated by hydrogen bonds, reduce the connection of ions in the system, and accelerate the mass transfer process. In particular, the cavitation effect generated by ultrasound forms a local high-temperature and high-pressure environment in the reaction system, accelerating the reaction rate. The solution is strongly agitated, significantly reducing the diffusion resistance of the solute, and improving the mass transfer efficiency. Therefore, the physicochemical effects of ultrasound can change the physicochemical properties of the treated medium, improve the chemical reaction conditions, and accelerate the chemical reaction rate, thereby achieving efficient degradation of key organic impurities in sodium aluminate solution.

[0121] (2) The advantages of ozone nanobubble technology are as follows: ① Due to its small size, the speed at which nanobubbles rise in the solution due to buoyancy is almost zero, so they can exist in the liquid phase for an extremely long time, effectively extending the half-life of ozone in the liquid phase, making the use of ozone more economical and environmentally friendly; ② Due to the small diameter and size of nanobubbles, the surface tension at the gas-liquid interface is relatively large, which produces pressure on the gas inside the bubble and compresses it. The increase in pressure inside the bubble causes the gas inside the bubble to continuously pass through the gas-liquid interface and dissolve into the water. This self-pressurization performance of the nanobubble during the contraction process significantly enhances the mass transfer efficiency at the gas-liquid interface; ③ Negatively charged ions are adsorbed on the surface of the nanobubble, first forming a surface charge ion layer, and then a positively charged counter-charge ion layer is adsorbed around the surface charge ions, generating a potential difference often expressed as Zeta potential. Due to their extremely small diameter, nanobubbles have a significantly higher zeta potential than microbubbles, resulting in a high adsorption capacity for charged particles in water. ④ Nanobubble technology can suppress the negative effects of temperature and pH on ozonation efficiency, maintaining a high ozone solubility even at elevated temperatures and decreasing pH. ⑤ Nanobubbles gradually shrink until they burst, at which point the gas-liquid interface disappears, causing drastic changes. The energy stored in the high-concentration positive and negative ion layers accumulated on the surface is instantly released, prompting the decomposition of H2O under the extreme conditions of local high temperature and high pressure, generating and stimulating a large number of highly oxidizing active free radicals, thereby achieving efficient degradation of organic impurities.

[0122] (3) The advantages of the swirl mixing reactor are as follows: the swirl blades 3 attached to the tank wall, the swirl channels 4 etched on the tank wall, and the nanopores 5 evenly arranged on the surface of the swirl channels 4 and the swirl blades 3 can significantly increase the turbulent vortex in the impact zone, enhance the turbulence intensity and radial pressure gradient, and thus effectively accelerate the mixing efficiency and reaction rate between ozone nanobubbles and organic matter in the sodium aluminate solution.

[0123] (4) Currently, the average cost of degrading one ton of organic carbon in the alumina industry is approximately RMB 30,000. The average cost of degrading one ton of organic carbon in sodium aluminate solution using micron bubble ozone oxidation technology is approximately RMB 29,400, while the average cost of degrading one ton of organic carbon in sodium aluminate solution using ultrasonically enhanced ozone nanobubble technology is approximately RMB 15,300. In summary, the large-scale use of this device in the alumina industry is expected to reduce energy consumption by approximately 49%.

[0124] The present invention, based on the cavitation effect and mechanical effect, uses an ultrasonic external field to enhance the ozone nanobubble strategy, solving the technical bottlenecks faced by the current wet oxidation process, such as high temperature and high pressure, the explosion of non-condensable gases (such as hydrogen) in the product, serious safety hazards, the short residence time of micron bubbles, and low mass transfer efficiency. Through the ultrasound-assisted nanobubble technology, various indicators can be significantly improved, such as extending the ozone bubble lifetime by 960 times, increasing the ozone bubble density by 120 times, reducing the ozone bubble diameter by 210 times, increasing the ozone bubble solubility by 26 times, increasing the ozone bubble Zeta potential by 4 times, increasing the ozone bubble volume mass transfer coefficient by 18 times, and ultimately increasing the organic matter oxidation rate by 3 times. This device is expected to economically eliminate the negative impact of organic matter on alumina production, solve the problems of low removal rate or high cost of traditional processes, enrich my country's bauxite resources and fully utilize high-quality bauxite from abroad, and provide a theoretical basis and technical support for the high-value utilization and sustainable development of the alumina industry.

[0125] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A device for degrading organic impurities in sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclonic flow, characterized by: The invention comprises an ozone nano bubble generating mechanism and a reaction mechanism, wherein the ozone nano bubble generating mechanism comprises an ozone generator and a nano bubble generator, wherein the air inlet of the ozone generator is used to introduce oxygen, the ozone generator can convert the oxygen into ozone gas, the air outlet of the ozone generator is used to pass the ozone gas, and the air outlet of the ozone generator is connected to the air inlet of the nano bubble generator, the nano bubble generator can make the ozone gas form ozone nano bubbles, and the air outlet of the nano bubble generator is used to pass the ozone nano bubbles; the reaction mechanism comprises a cyclone mixing reactor and an ultrasonic generator, the cyclone The air inlet of the cyclone mixing reactor is communicated with the air outlet of the nano bubble generator, the liquid inlet of the cyclone mixing reactor is used to introduce the sodium aluminate solution, and the cyclone mixing reactor can form a cyclone of the sodium aluminate solution and mix it with the ozone nano bubbles. The ultrasonic generator is arranged on the cyclone mixing reactor, and the ultrasonic generator can irradiate the cyclone mixing reactor with ultrasonic waves, so that the ozone nano bubbles degrade the organic impurities in the sodium aluminate solution under the ultrasonic radiation state; the cyclone mixing reactor includes a reaction tank and a circulation pump, the upper part of the reaction tank is a cylindrical structure, and the reaction tank is a cylindrical structure. The lower part of the tank is an inverted cone structure; the upper inner wall of the reaction tank is provided with swirl blades, the swirl blades are arc-shaped blades, and the swirl blades are arranged in a plurality from the outside to the inside, and all the swirl blades are evenly distributed on the upper inner wall of the reaction tank along the circumferential direction; the lower inner wall of the reaction tank is provided with a swirl channel, the swirl channel is a groove structure, and the swirl channel is spirally wound on the lower inner wall of the reaction tank; the upper part of the reaction tank is provided with a sodium aluminate solution inlet and a circulation port, and the lower part of the reaction tank is provided with an ozone nano bubble inlet and a drain port, wherein the sodium aluminate solution inlet is used to pass the sodium aluminate solution, The ozone nanobubble inlet is connected to the air outlet of the nanobubble generator, and the drain port is connected to the circulation port through a circulation pipeline. The circulation pump is provided on the circulation pipeline, and a drain pipe is further connected to the circulation pipeline at a position between the drain port and the circulation pump, and a drain valve is provided on the drain pipe. The nanobubble generator includes a nanobubble generating chamber, a cutting assembly, and a motor. The nanobubble generating chamber is provided with an ozone gas inlet and an ozone nanobubble outlet. The ozone gas inlet is connected to the air outlet of the ozone generator, and the ozone nanobubble outlet is connected to the air inlet of the cyclone mixing reactor.The cutting assembly is disposed within the nanobubble generating chamber and includes a diaphragm and a rotating shaft. The surface of the diaphragm is densely covered with nanopores, and the diaphragm is provided with a plurality of nanopores. All the diaphragms are evenly penetrated on the rotating shaft. The rotating shaft is connected to the output end of the motor. The motor can drive the rotating shaft to rotate, thereby driving the diaphragm to rotate and cut the ozone gas in the nanobubble generating chamber, thereby forming the ozone nanobubbles from the ozone gas.

2. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1, characterized in that: Nanopores are distributed on the surface of the swirl blade and the inner wall of the swirl channel.

3. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1, characterized in that: The ultrasonic generator includes a horn and a transducer. The horn is inserted into the reaction tank, and the transducer is connected to the horn.

4. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1, characterized in that: The ozone generator includes a honeycomb ozone discharge chamber and a high-voltage inverter power supply. The honeycomb ozone discharge chamber is provided with an oxygen inlet and an ozone gas outlet. The oxygen inlet is used to introduce the oxygen. The ozone gas outlet is connected to the ozone gas inlet of the nanobubble generating chamber. The honeycomb ozone discharge chamber is connected to the high-voltage inverter power supply to perform high-voltage discharge on the oxygen to generate the ozone gas.

5. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1, characterized in that: The device for degrading organic impurities in a sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclones also includes a tail gas treatment mechanism. The gas outlet of the cyclone mixing reactor is used to discharge the ozone tail gas, and the gas outlet of the cyclone mixing reactor is connected to the gas inlet of the tail gas treatment mechanism. The tail gas treatment mechanism can purify the ozone tail gas, and the gas outlet of the tail gas treatment mechanism is used to discharge the purified ozone tail gas.

6. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 5, characterized in that: The tail gas treatment mechanism includes a tail gas treatment chamber, which is provided with an ozone tail gas inlet and an exhaust port. The ozone tail gas inlet is located at the bottom of the tail gas treatment chamber and is connected to the gas outlet of the cyclone mixing reactor. The tail gas treatment chamber is provided with a catalytic ultraviolet irradiation layer, a chemical absorption layer and an activated carbon adsorption layer from bottom to top. The exhaust port is located at the top of the tail gas treatment chamber, and the exhaust port is used to discharge the purified ozone tail gas.

7. A method for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow, characterized in that: The device for degrading organic impurities in a sodium aluminate solution using ozone nanobubbles coupled with ultrasonic cyclonic flow according to any one of claims 1 to 6 comprises the following steps: Step 1: introducing the oxygen into the ozone generator, and converting the oxygen into the ozone gas through the ozone generator; Step 2, forming the ozone nanobubbles from the ozone generator through the nanobubble generator; Step 3: The sodium aluminate solution is introduced into the cyclone mixing reactor, the sodium aluminate solution is cycloned by the cyclone mixing reactor, and mixed with the ozone nanobubbles from the nanobubble generator. At the same time, the ozone nanobubbles are irradiated by the ultrasonic generator to degrade organic impurities in the sodium aluminate solution until the target is reached and the ozone oxidation reaction is stopped.

8. The method for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 7, characterized in that: The organic carbon content in the sodium aluminate solution is 1-15 g / L; The ratio of the mass of the ozone gas to the volume of the sodium aluminate solution is (1-20) g:1 L; The frequency of ultrasound is 20~40kHz; The ratio of ultrasonic power to the volume of the sodium aluminate solution is (0.02-0.2) kW:1 L; Ultrasound was intermittent, with a working time of 0.1 to 9.9 seconds and an interval of 0.1 to 1 second between two adjacent ultrasounds. The existence time of the ozone nanobubbles is 10,000 to 30,000 minutes; The density of the ozone nanobubbles is 0.1~10×10 8 / mL; The diameter of the ozone nanobubbles is 10-200 nm; The dissolved amount of the ozone nanobubbles is 1-10 mg / L; The zeta potential of the ozone nanobubbles is -30 to -60 mV; The volume mass transfer coefficient of the ozone nanobubbles is 1~5min -1 ; The temperature of ultrasound-assisted ozone nanobubble oxidation reaction is 25~80℃, and the reaction time is 10min~3h; In the step three, the ozone tail gas in the cyclone mixing reactor is introduced into the tail gas treatment mechanism, and is purified by passing through a catalytic ultraviolet irradiation layer using ultraviolet light with a wavelength of 200 to 400 nm, a chemical absorption layer using a Na2S2O3 solution with a molar concentration of 0.1 to 1 mol / L, and an activated carbon adsorption layer using honeycomb activated carbon with a pore size of 0.1 to 3 mm.

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