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

Abstract

The invention discloses a device and method for degrading organic impurities in a sodium aluminate solution through ozone nanobubble coupling ultrasonic rotational flow, and relates to the technical field of aluminum oxide production, the device 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 nano-bubble generator can enable the ozone gas from the ozone generator to form ozone nano-bubbles; the reaction mechanism comprises a rotational flow mixing reactor and an ultrasonic generator, a liquid inlet of the rotational flow mixing reactor is used for introducing a sodium aluminate solution, the rotational flow mixing reactor can enable the sodium aluminate solution to form rotational flow and mix the rotational flow with the ozone nanobubbles, and the ultrasonic generator is arranged on the rotational flow mixing reactor; the ultrasonic generator can perform ultrasonic radiation on the inside of the rotational flow mixing reactor, so that the ozone nano bubbles degrade organic impurities in the sodium aluminate solution in an ultrasonic radiation state.

Description

Technical Field

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

[0002] The output of the metal aluminum industry and electrolytic aluminum plays a decisive role in the demand for alumina. Bauxite is the main raw material for aluminum production. It must go through the intermediate refining stage of the Bayer process to produce alumina, and then produce primary aluminum through the electrolytic process. At present, more than 95% of Al2O3 in the world is produced by the Bayer process. In this process, a large amount of organic matter can be brought in by bauxite and other flocculants, additives, etc., which accumulates continuously during the Bayer process of producing alumina, which can lead to problems such as reduced quality of alumina products, fine 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 and 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 applicable to the removal of sodium oxalate; the lime causticization method usually causes the loss of alumina 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 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 the oxidation of organic matter, the slurry from the tubular reactor enters the Bayer process insulation retention tank, autoclave or self-evaporator. However, the current wet oxidation process has problems such as harsh reaction conditions (high temperature and high pressure), non-condensable gases (such as hydrogen) in the reaction products are prone to explosion, and serious safety hazards. It is necessary to develop a low-temperature and normal-pressure oxidation method to degrade organic impurities in sodium aluminate solution.

[0004] Ozone oxidation, as a typical low-temperature and normal-pressure oxidation technology, has great application prospects for the degradation of organic impurities in sodium aluminate solutions. However, there are currently very few related studies in this field. Miguel Antonio Soplin Pastor and others from the University of São Paulo in Brazil explored the effects of ozone systems and ozone and hydrogen peroxide combined systems on the removal of organic matter in Bayer liquor. Since 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 are easily broken in water; due to the large specific surface area, micron ozone bubbles will quickly escape from 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 in the reaction products (such as hydrogen) 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 a problem that needs to be solved urgently. Summary of the invention

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

[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 an ozone nano bubble with an ultrasonic cyclone. The device comprises an ozone nano bubble generating mechanism and a reaction mechanism. The ozone nano bubble generating mechanism comprises an ozone generator and a nano bubble generator. 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. The air outlet of the ozone generator is connected to the air inlet of the nano bubble generator. The nano bubble generator can form ozone nano bubbles from the ozone gas. The air outlet of the nano bubble generator is used to pass the ozone gas. The reaction mechanism comprises a cyclone mixing reactor and an ultrasonic generator, 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 a sodium aluminate solution, and the cyclone mixing reactor can make the sodium aluminate solution form a cyclone and mix with the ozone nano bubbles, the ultrasonic generator is arranged on the cyclone mixing reactor, and the ultrasonic generator can perform ultrasonic radiation in the cyclone mixing reactor, so that the ozone nano bubbles can degrade the organic impurities in the sodium aluminate solution under the ultrasonic radiation state.

[0009] Preferably, the swirl mixing reactor comprises 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 provided obliquely downward 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 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 nano bubble inlet and a drainage port, wherein the sodium aluminate solution inlet is used to introduce the sodium aluminate solution, the ozone nano bubble inlet is communicated with the gas outlet of the nano bubble generator, the drainage port is communicated with the circulation port through a circulation pipeline, the circulation pump is arranged on the circulation pipeline, and a drainage pipe is also connected to a position on the circulation pipeline between the drainage port and the circulation pump, and a drainage valve is arranged on the drainage pipe.

[0011] Preferably, nanopores are evenly 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 inserted into 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 nano bubble 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 also includes a tail gas treatment mechanism, the gas outlet of the cyclone mixing reactor is used to pass out 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 pass out 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, wherein 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, and a catalytic ultraviolet irradiation layer, a chemical absorption layer and an activated carbon adsorption layer are sequentially arranged in the exhaust gas treatment chamber from bottom to top, and the exhaust port is located at the top of the exhaust gas treatment chamber, and the exhaust port is used to pass the purified ozone exhaust gas.

[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 adopts the above-mentioned device for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones, and 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 gas from the ozone generator through the nanobubble generator;

[0020] Step three, passing the sodium aluminate solution into the cyclone mixing reactor, forming a cyclone through the cyclone mixing reactor, and mixing with the ozone nanobubbles from the nanobubble generator, and at the same time, using the ultrasonic generator to degrade organic impurities in the sodium aluminate solution under ultrasonic radiation, until the ozone oxidation reaction is stopped after the target is reached.

[0021] Preferably, the content of organic carbon 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:1L;

[0025] Ultrasound is intermittent ultrasound, the working time of ultrasound is 0.1~9.9s, and the interval between two adjacent ultrasounds is 0.1~1s;

[0026] The existence time of the ozone nanobubbles is 10000 to 30000 minutes;

[0027] The density of the ozone nanobubbles is 0.1 to 10×10 8 Pieces / 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 10min-3h;

[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 a 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 device for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclones provided by the present invention 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, and the oxygen is converted into ozone gas by the ozone generator, and the ozone gas from the ozone generator is formed into ozone nanobubbles by the nanobubble generator. Then, the sodium aluminate solution is introduced into the cyclone mixing reactor, and the sodium aluminate solution is formed into a cyclone by the cyclone mixing reactor, and mixed with the ozone nanobubbles from the nanobubble generator. At the same time, the ozone nanobubbles are used to degrade the organic impurities in the sodium aluminate solution under ultrasonic radiation by the ultrasonic generator until the ozone oxidation reaction is stopped after the target is reached.

[0036] It can be seen that the present invention can change the physical and chemical properties of the treated medium by setting an ultrasonic generator and applying ultrasonic technology, thereby improving the chemical reaction conditions and accelerating the chemical reaction rate, thereby realizing efficient degradation of key organic impurities in the sodium aluminate solution; the present invention can significantly enhance the mass transfer efficiency at the gas-liquid interface by setting an ozone generator and a nanobubble generator, and stimulate a large number of active free radicals with extremely strong oxidizing properties, thereby realizing efficient degradation of organic impurities; the present invention can effectively accelerate the mixing efficiency and reaction rate between the ozone nanobubbles and the organic matter in the sodium aluminate solution by setting a cyclone mixing reactor. 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 drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0038] Figure 1 A schematic diagram of a device for degrading organic impurities in a sodium aluminate solution by 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 a reaction tank provided in Example 1 of the present invention (from a top view);

[0040] Figure 3 A schematic diagram of a process flow of a method for degrading organic impurities in a sodium aluminate solution by 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 ultrasonic 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 ultrasonic enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0043] Figure 6 This is a comparison diagram of the diameters of ozone bubbles in the ozone microbubble system, the ozone nanobubble system, and the ultrasonic 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 amount of the ozone microbubble system, the ozone nanobubble system and the ultrasonic enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0045] Figure 8 This is a comparison diagram 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] Fig. 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 ultrasonic enhanced ozone nanobubble system in Application Example 1 of the present invention;

[0047] Fig.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-drainage port, 2-circulation pump, 3-swirl blade, 4-swirl channel, 5-nanopore, 6-circulation pipeline, 7-drainage pipe, 8-drainage 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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

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

[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] Embodiment 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 make the ozone gas form ozone nanobubbles, and the outlet of the nanobubble generator is connected to the air inlet of the nanobubble generator. The air port is used to pass out ozone nanobubbles; the reaction mechanism includes a cyclone mixing reactor and an ultrasonic generator, the air inlet of the cyclone mixing reactor is connected with the air outlet of the nanobubble generator, the liquid inlet of the cyclone mixing reactor is used to pass the sodium aluminate solution, and the cyclone mixing reactor can make the sodium aluminate solution form a cyclone and mix with the ozone nanobubbles, the ultrasonic generator is arranged on the cyclone mixing reactor, and the ultrasonic generator can perform ultrasonic radiation in the cyclone mixing reactor, so that the ozone nanobubbles can degrade the organic impurities in the sodium aluminate solution under the ultrasonic radiation state.

[0054] In this embodiment, the cyclone 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, and all the swirl blades 3 are uniformly 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 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, and a swirl effect is generated under the guidance of the swirl blades 3 and the swirl channel 4; 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 of the reaction tank 1, and 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 portion of the reaction tank 1, and an ozone nano bubble inlet 103 and a drain port 104 are provided at the lower portion of the reaction tank 1, wherein the sodium aluminate solution inlet 101 is used to introduce the sodium aluminate solution, the ozone nano bubble inlet 103 is connected to the air outlet of the nano bubble generator, 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 of 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 transformer 9 and a transducer 10, the transformer 9 is inserted into the reaction tank 1, and the transducer 10 is connected to the transformer 9; specifically, the transducer 10 and the transformer 9 in this embodiment are connected by a double-headed stud, and 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 transformer 9, thereby enhancing the energy concentration of the ultrasonic wave, improving the vibration efficiency, and optimizing the ultrasonic wave strengthening effect; the ultrasonic generator in this embodiment also includes a first cooling fan 11, and the first cooling fan 11 is used to cool the transducer 10.

[0057] In this embodiment, the nano bubble generator includes a nano bubble generating chamber 12, a cutting assembly and a motor 13. The nano bubble generating chamber 12 is provided with an ozone gas inlet 1201 and an ozone nano bubble outlet 1202. The ozone gas inlet 1201 is connected to the air outlet of the ozone generator, and the ozone nano bubble outlet 1202 is connected to the air inlet of the cyclone mixing reactor; the cutting assembly is arranged in the nano bubble 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 diaphragms. 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 nano bubble generating chamber 12, so that the ozone gas forms ozone nano bubbles, that is, through the high-speed rotation cutting of the diaphragm 14, the ozone gas forms a large number of fine ozone nano bubbles, ensuring the uniform distribution and efficient generation of ozone nano bubbles.

[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 nano bubble 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, and 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 flowmeter and a valve are provided on the oxygen delivery pipeline; the ozone generator in this embodiment also includes a second cooling fan 18, and the second cooling fan 18 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 ozone nanobubbles coupled with ultrasonic cyclones also includes a tail gas treatment mechanism, the gas outlet of the cyclone mixing reactor is used to pass out 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 pass out the purified ozone tail 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. A catalytic ultraviolet irradiation layer 20, a chemical absorption layer 21 and an activated carbon adsorption layer 22 are sequentially arranged in the exhaust gas treatment chamber 19 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 for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow provided in this embodiment is as follows:

[0062] Ozone is generated by high-voltage discharge of oxygen in the ozone generator; a large number of tiny ozone nanobubbles are formed after the ozone gas is passed into the nanobubble generator; the ozone nanobubbles and the sodium aluminate solution containing a large amount of organic impurities are passed into the cyclone mixing reactor, and the oxidation degradation process of organic matter is further efficiently enhanced by the ultrasonic generator, and the reaction is stopped after the rapid catalytic oxidation is achieved until the target is reached; the 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 and continues to be recycled.

[0063] Embodiment 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 for degrading organic impurities in a sodium aluminate solution by using 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, and converting the oxygen into ozone gas through the ozone generator;

[0066] Step 2, forming ozone nanobubbles from the ozone gas of the ozone generator through a nanobubble generator;

[0067] Step three, passing the sodium aluminate solution into a cyclone mixing reactor, the cyclone mixing reactor is used to form a cyclone of the sodium aluminate solution, and the cyclone is mixed with the ozone nanobubbles from the nanobubble generator. At the same time, the ozone nanobubbles are used to degrade the organic impurities in the sodium aluminate solution under ultrasonic radiation by an ultrasonic generator until the ozone oxidation reaction is stopped after the target is reached.

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

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

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

[0072] In step three, the ozone exhaust gas in the cyclone mixing reactor is introduced into the exhaust 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 a honeycomb activated carbon with a pore size of 0.1 to 3 mm.

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

[0074] Application Example 1

[0075] Specific reaction parameters: 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 a 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] Figure 4-Figure 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-synergistic 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 dissolution amount 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 Application Example 1 Comparison of the degradation effects of two systems 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: 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 a 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 a 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: 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 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 uses honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 uses a Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 uses ultraviolet light with a wavelength of 254nm. The organic matter degradation results are shown in Table 4. For the ultrasonic enhanced ozone nanobubble system, the organic impurity degradation efficiency is significantly improved with the increase of ultrasonic power density.

[0096] Table 4 Comparison of the degradation effects of organic impurities in sodium aluminate solution at different power densities in the ultrasonic 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: 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 is 25℃, the reaction time is 1.5h, and the ozone tail gas is treated in three layers continuously, wherein the activated carbon adsorption layer 22 uses honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 uses a Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 uses ultraviolet light with a wavelength of 254nm. The organic matter degradation results are shown in Table 5. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

[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: 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 is 55°C, the reaction time is 3h, and the ozone tail gas is treated in three layers continuously, wherein the activated carbon adsorption layer 22 uses honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 uses a Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 uses ultraviolet light with a wavelength of 254nm. The organic matter degradation results are shown in Table 6. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

[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: 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 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 uses honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 uses a Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 uses ultraviolet light with a wavelength of 254nm. The organic matter degradation results are shown in Table 7. For the ultrasonic enhanced ozone nanobubble system, the organic impurity degradation efficiency shows a downward trend with the increase of ultrasonic frequency.

[0111] Table 7 Comparison of the degradation effects of different power frequencies on organic impurities in sodium aluminate solution in the ultrasonic 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 the first application example, but the size of the ozone nanobubbles is different (the size of the ozone nanobubbles is adjusted by controlling the rotation speed of the motor 13 and the size of the densely distributed nanopores on the diaphragm 14).

[0115] Specific reaction parameters: 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 30000 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 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 uses honeycomb activated carbon with a pore size of 0.5mm, the chemical absorption layer 21 uses a Na2S2O3 solution with a molar concentration of 0.5mol / L, and the catalytic ultraviolet irradiation layer 20 uses ultraviolet light with a wavelength of 254nm. The organic matter degradation results are shown in Table 8. Compared with the ozone microbubble system, the degradation efficiency of organic impurities in the ultrasound-enhanced ozone nanobubble system is significantly improved.

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

[0117]

[0118] Through the above experiments, it can be seen that the use of the present invention (ultrasonic enhanced ozone nanobubble system) to degrade key organic impurities in sodium aluminate solution can significantly improve the degradation effect of organic matter, and the purified sodium aluminate solution is more suitable for alumina production system. The present invention makes the degradation cost of key organic impurities in sodium aluminate solution lower, the degradation efficiency higher, and easy to achieve industrialization.

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

[0120] (1) Power ultrasonic technology, which is known as "industrial MSG" by the American industry, is a high-tech technology based on physics, mechanical vibration, materials and other disciplines. 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 balance 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 interface effect, that is, the changes in the solution caused by the gathering of bubbles in the solution can destroy the outer layer of mineral particles, form cavities, accelerate material migration and transformation, and increase the metal leaching rate; ④ an energy-gathering effect, that is, a high-pressure impact flow that can break the intermolecular force is generated in the solution, changing the metastable state generated by hydrogen bonds, reducing the connection of ions in the system, and accelerating 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, which accelerates 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 effect 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 extremely 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 a very 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 extremely 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. The 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 that is often expressed as Zeta potential. Due to their extremely small diameter, the Zeta potential of nanobubbles is significantly higher than that of microbubbles, so they have a high adsorption performance for charged particles in water; ④ Nanobubble technology can inhibit the negative effects of temperature and pH on ozonation efficiency, and can maintain a high ozone solubility even when the temperature rises and the pH value decreases; ⑤ Nanobubbles will gradually become smaller until they burst. When they burst, the gas-liquid interface disappears and a drastic change occurs. The energy accumulated in the high-concentration positive and negative ion layers accumulated on the surface is released instantly, which promotes the decomposition of H2O under the extreme conditions of local high temperature and high pressure and produces and excites a large number of active free radicals with extremely strong oxidizing properties, 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 the ozone nanobubbles and the organic matter in the sodium aluminate solution.

[0123] (4) At present, the average price of degrading 1 ton of organic carbon in the alumina industry is about 30,000 yuan. The average price of degrading 1 ton of organic carbon in sodium aluminate solution by micron bubble ozone oxidation technology is about 29,400 yuan, while the average price of degrading 1 ton of organic carbon in sodium aluminate solution by ultrasonic enhanced ozone nanobubble technology is about 15,300 yuan. In summary, the large-scale use of this device in the alumina industry is expected to reduce energy consumption by about 49%.

[0124] Based on the cavitation effect and mechanical effect, the present invention solves the technical bottlenecks of the current wet oxidation process, such as high temperature and high pressure, non-condensable gas (such as hydrogen) in the product is easy to cause explosion, serious safety hazards, short residence time of micron bubbles and low mass transfer efficiency, etc., through the ultrasonic synergistic nanobubble technology, various indicators can be significantly improved, such as extending the existence time of ozone bubbles by 960 times, increasing the density of ozone bubbles by 120 times, reducing the diameter of ozone bubbles by 210 times, increasing the amount of ozone bubbles dissolved by 26 times, increasing the Zeta potential of ozone bubbles by 4 times, increasing the volume mass transfer coefficient of ozone bubbles by 18 times, and finally increasing the oxidation rate of organic matter by 3 times. The device is expected to provide a theoretical basis and technical support for economically eliminating the negative impact of organic matter on alumina production, solving the problems of low removal rate or high cost of traditional processes, enriching my country's bauxite resources and making full use of foreign high-quality bauxite, and has important scientific value and practical significance 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 used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood 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 in that: 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, 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 The invention comprises a cyclone mixing reactor and an ultrasonic generator, wherein 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 a sodium aluminate solution, and the cyclone mixing reactor can make the sodium aluminate solution form a cyclone and mix with the ozone nano bubbles, the ultrasonic generator is arranged on the cyclone mixing reactor, and the ultrasonic generator can perform ultrasonic radiation in the cyclone mixing reactor, so that the ozone nano bubbles can degrade organic impurities in the sodium aluminate solution under ultrasonic radiation.

2. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1 is characterized in that: The cyclone mixing reactor comprises a reaction tank and a circulation pump, wherein 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 cyclone blades, the cyclone blades are arc-shaped blades, and a plurality of cyclone blades are provided obliquely downward from the outside to the inside, and all the cyclone 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 cyclone channel, the cyclone channel is a groove structure, and the cyclone 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 drainage port, wherein the sodium aluminate solution inlet is used to introduce the sodium aluminate solution, the ozone nano bubble inlet is communicated with the gas outlet of the nano bubble generator, the drainage port is communicated with the circulation port through a circulation pipeline, the circulation pump is arranged on the circulation pipeline, and a drainage pipe is also connected to a position on the circulation pipeline between the drainage port and the circulation pump, and a drainage valve is arranged on the drainage pipe.

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

4. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 2 is characterized in that: The ultrasonic generator comprises a horn and a transducer, wherein the horn is inserted into the reaction tank, and the transducer is connected to the horn.

5. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1 is characterized in that: The nano bubble generator comprises a nano bubble generating chamber, a cutting assembly and a motor, wherein the nano bubble generating chamber is provided with an ozone gas inlet and an ozone nano bubble outlet, wherein the ozone gas inlet is communicated with the gas outlet of the ozone generator, and the ozone nano bubble outlet is communicated with the gas inlet of the cyclone mixing reactor; the cutting assembly is arranged in the nano bubble generating chamber, wherein the cutting assembly comprises a diaphragm and a rotating shaft, wherein the surface of the diaphragm is densely covered with nano pores, and the diaphragm is provided with a plurality of nano pores, and all the diaphragms are uniformly penetrated on the rotating shaft, the rotating shaft is connected with 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 nano bubble generating chamber, thereby forming the ozone nano bubbles from the ozone 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 ozone generator comprises a honeycomb ozone discharge chamber and a high-voltage inverter power supply, wherein the honeycomb ozone discharge chamber is provided with an oxygen inlet and an ozone gas outlet, wherein the oxygen inlet is used to introduce the oxygen, and the ozone gas outlet is communicated with the ozone gas inlet of the nano bubble 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.

7. The device for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 1 is 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, 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 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.

8. The device 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 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. A catalytic ultraviolet irradiation layer, a chemical absorption layer and an activated carbon adsorption layer are sequentially arranged in the tail gas treatment chamber 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 pass the purified ozone tail gas.

9. A method for degrading organic impurities in sodium aluminate solution by coupling ozone nanobubbles with ultrasonic cyclonic flow, characterized in that: The device for degrading organic impurities in a sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow as claimed in any one of claims 1 to 8 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 gas from the ozone generator through the nanobubble generator; Step three, passing the sodium aluminate solution into the cyclone mixing reactor, forming a cyclone through the cyclone mixing reactor, and mixing with the ozone nanobubbles from the nanobubble generator, and at the same time, using the ultrasonic generator to degrade organic impurities in the sodium aluminate solution under ultrasonic radiation, until the ozone oxidation reaction is stopped after the target is reached.

10. The method for degrading organic impurities in sodium aluminate solution by using ozone nanobubbles coupled with ultrasonic cyclonic flow according to claim 9, characterized in that: The content of organic carbon in the sodium aluminate solution is 1 to 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 to 40 kHz; The ratio of ultrasonic power to the volume of the sodium aluminate solution is (0.02-0.2) kW:1L; Ultrasound is intermittent ultrasound, the working time of ultrasound is 0.1~9.9s, and the interval between two adjacent ultrasounds is 0.1~1s; The existence time of the ozone nanobubbles is 10000 to 30000 minutes; The density of the ozone nanobubbles is 0.1 to 10×10 8 Pieces / mL; The diameter of the ozone nanobubbles is 10 to 200 nm; The dissolved amount of the ozone nanobubbles is 1 to 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 to 5 min -1 ; The temperature of ultrasound-assisted ozone nanobubble oxidation reaction is 25-80°C, 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 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 a honeycomb activated carbon with a pore size of 0.1 to 3 mm.

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