Organic matter removal device for Bayer alumina production

Abstract

An organic matter removal device for Bayer alumina production relates to the technical field of alumina production and is used for removing organic matters in alumina mother liquor. The organic matter removal device comprises a shell, an upper partition plate and a lower partition plate are arranged in the shell, the space in the shell is divided into an upper partition cavity, a middle partition cavity and a lower partition cavity by the upper partition plate and the lower partition plate, the upper partition cavity is provided with a concentrated organic matter liquid outlet, the middle partition cavity is provided with a removed organic matter liquid outlet, and the lower partition cavity is provided with a mother liquor inlet; a plurality of communicating pipes are connected between the upper partition plate and the lower partition plate in a penetrating mode, and the upper partition cavity is communicated with the lower partition cavity through the communicating pipes. The communicating pipe is composed of a membrane filter pipe and a negative electrode pipe, the membrane filter pipe is connected above the negative electrode pipe, and a corona discharge electrode is arranged outside the negative electrode pipe. The membrane filter pipe can filter macromolecular organic matters in the mother liquor, and active particles generated by the corona discharge system can oxidize and decompose micromolecular organic matters in the mother liquor, so that the comprehensive removal rate of the organic matters is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of alumina production, in particular to an organic matter removal device for Bayer alumina production. Background Art

[0002] At present, most of the alumina in the world is produced by the Bayer process. In the Bayer process of alumina production, bauxite is mixed with alkali solution and then boiled to dissolve the mother liquor. Along with the dissolution of the mother liquor, organic matter such as humic acid will also dissolve into the mother liquor. When the organic matter accumulates to a certain extent, it will have an adverse effect on the subsequent production of alumina.

[0003] The existing organic matter removal methods used in alumina production mainly include bauxite roasting method, solution oxidation method, precipitation method, ion exchange method and causticization method. The above methods all have their own advantages and disadvantages, but the comprehensive removal rate of organic matter is low. The closest existing patent is an organic matter removal device in an alumina production process disclosed in CN217139562U. The patent performs preliminary filtration of the Bayer process mother liquor by setting the gravity factor of the Bayer process mother liquor and the elastic deformation of the buffer spring, so that the Bayer process mother liquor can be separated into a concentrated organic solution and an organic solution, and the filter screen and guide plate with an acute inclination angle can allow the concentrated organic solution to enter the collection box, and the reverse osmosis membrane performs secondary filtration on the solution inside the collection box, thereby improving the collection capacity of the organic matter removal device, and the operation is simple and efficient. In addition, the organic matter removal device in the alumina production process adjusts the vertical height of the filter box and the collection box by setting a cylinder, which is convenient for people to collect the organic solution removed by the device, and the through hole can assist the concentrated organic matter inside the filter box to enter the collection box to ensure the solution separation effect. The cleaning port and the second organic solution outlet located on the same vertical plane can enhance the cleaning efficiency of the device and facilitate the cleaning of the device. The collection box with an inverted truncated cone shape at the bottom effectively improves the collection capacity of the device. This patent highlights the ability to collect organic matter, and does not disclose technical measures that are conducive to improving the comprehensive removal rate of organic matter. Utility Model Content

[0004] In order to overcome the deficiencies in the background technology, the utility model discloses an organic matter removal device for Bayer alumina production, the purpose of which is to improve the comprehensive removal rate of organic matter.

[0005] Specifically, the utility model adopts the following technical solutions:

[0006] An organic matter removal device for Bayer alumina production is used to remove organic matter in mother liquor; the organic matter removal device comprises a shell, an upper partition and a lower partition are arranged in the shell, the upper partition and the lower partition divide the space in the shell into an upper compartment, a middle compartment and a lower compartment, the upper compartment is provided with a concentrated organic matter liquid outlet, the middle compartment is provided with a de-organic matter liquid outlet, and the lower compartment is provided with a mother liquor inlet; a plurality of connecting pipes are connected through the upper partition and the lower partition, and the upper compartment is connected with the lower compartment through the connecting pipes; the connecting pipes are composed of a membrane filter tube and a cathode tube, the membrane filter tube is connected above the cathode tube, and a corona discharge electrode is arranged outside the cathode tube.

[0007] To further improve the technical solution, a positive tube is arranged outside the negative tube, and the corona discharge electrode array is arranged on the inner tube wall of the positive tube.

[0008] To further improve the technical solution, the distance between the corona discharge electrode and the cathode tube is 5-15 mm.

[0009] To further improve the technical solution, a mixed gas inlet is provided on the middle partition cavity, and the mixed gas inlet is used to introduce the mixed gas into the middle partition cavity.

[0010] To further improve the technical solution, the outer diameter of the negative electrode tube is greater than the outer diameter of the membrane filtration tube.

[0011] After implementing the above technical solution, compared with the background technology, the beneficial effects produced by the utility model are:

[0012] The organic matter removal device has a membrane filter tube and a corona discharge system. The membrane filter tube can filter out the macromolecular organic matter in the mother liquor, and the active particles generated by the corona discharge system can oxidatively decompose the small molecular organic matter in the mother liquor. After filtration by the membrane filter tube and decomposition by corona discharge, 86-92% of the organic matter in the mother liquor can be removed, which greatly improves the comprehensive removal rate of organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 Shown is a schematic diagram of the cross-sectional structure of the organic matter removal device.

[0014] Attached Figure 2 Shown is a schematic diagram of the cross-sectional structure of the connecting pipe and the corona discharge electrode.

[0015] In the attached drawings: 1. Shell; 11. Mother liquor inlet; 12. Concentrated organic liquid outlet; 13. De-organic liquid outlet; 14. Mixed gas inlet; 15. Upper partition; 16. Lower partition; 17. Upper compartment; 18. Middle compartment; 19. Lower compartment; 2. Connecting tube; 21. Membrane filter tube; 22. Cathode tube; 3. Cathode tube; 4. Corona discharge electrode. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that in the description of the present invention, the terms "front", "rear", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of description, rather than indicating or implying that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0017] An organic matter removal device for Bayer alumina production is used to remove organic matter from alumina mother liquor. Its structure and function are described in detail below.

[0018] See attached Figure 1 , attached Figure 1 The figure shows the cross-sectional structure diagram of the organic matter removal device. Figure 1 It can be seen that the organic matter removal device includes a shell 1, in which an upper partition 15 and a lower partition 16 are provided, and the upper partition 15 and the lower partition 16 divide the space in the shell 1 into an upper compartment 17, a middle compartment 18 and a lower compartment 19. The upper compartment 17 is provided with a concentrated organic matter liquid outlet 12, the middle compartment 18 is provided with a de-organic matter liquid outlet 13, and the lower compartment 19 is provided with a mother liquid inlet 11. A plurality of connecting pipes 2 are connected through the upper partition 15 and the lower partition 16, and the upper compartment 17 is connected with the lower compartment 19 through the connecting pipes 2.

[0019] See attached Figure 2 , attached Figure 2 FIG. 2 shows a cross-sectional structure diagram of the connecting pipe 2 and the corona discharge electrode 4. Figure 2 It can be seen that the connecting tube 2 is composed of a membrane filter tube 21 and a cathode tube 22, the membrane filter tube 21 is connected to the top of the cathode tube 22, and the outer diameter of the cathode tube 22 is larger than the outer diameter of the membrane filter tube 21. A cathode tube 3 is arranged outside the cathode tube 22, and a corona discharge electrode 4 is arranged in an array on the inner tube wall of the cathode tube 3. Preferably, the distance between the corona discharge electrode 4 and the cathode tube 22 is 5-15 mm.

[0020] A ground wire is connected to the negative electrode tube 22, and a 800-1000V high voltage is connected to the positive electrode tube 3. After power is turned on, a corona discharge is generated between the corona discharge electrode 4 and the negative electrode tube 22. The corona discharge can ionize oxygen and nitrogen in the air, and then produce highly oxidizing active particles such as ozone, oxygen ions, nitrogen ions, and hydroxide. In addition, the corona discharge can also generate high temperature and ultraviolet radiation.

[0021] Working principle:

[0022] During operation, the upstream alumina mother liquor enters the lower compartment 19 of the housing 1 from the mother liquor inlet 11 after being pressurized by the pump, and then enters the upper compartment 17 through the connecting pipe 2, and finally flows out from the concentrated organic liquid outlet 12. The connecting pipe 2 is composed of a membrane filter tube 21 and a cathode tube 22. When the mother liquor flows through the connecting pipe 2, organic matter with a macromolecular structure cannot pass through the membrane and can only flow out from the concentrated organic liquid outlet 12, while the mother liquor and the small molecular organic matter contained in the mother liquor can pass through the membrane and flow downward along the outer wall of the membrane filter tube 21. After filtration through the membrane filter tube 21, 37-42% of the organic matter in the mother liquor can be removed.

[0023] When the filtrate flows onto the negative electrode tube 22, an annular water film is formed on the outer wall of the negative electrode tube 22, and the thickness of the water film is 0.5-3mm. Since the distance between the corona discharge electrode 4 and the negative electrode tube 22 is very close, strong corona discharge and a large number of active particles will be generated. Since the active particles are enriched on the water film, they have a very high concentration, and the active particles have a strong oxidizing property, they can decompose the small molecular organic matter in the water film through oxidation reaction, so the organic matter in the filtrate can be further removed. Practice has proved that after filtering through the membrane filter tube 21 and decomposing through corona discharge, 86-92% of the organic matter in the mother liquor can be removed. Finally, the filtrate filtered through the membrane filter tube 21 and decomposed through corona discharge becomes a de-organic liquid, and flows out from the de-organic liquid outlet 13.

[0024] The volume ratio of oxygen to nitrogen in the air is roughly 1:4, and the proportion of oxygen is low, which is not conducive to the production of more ozone and oxygen ions. In addition, there is a lack of argon in the air, and a very high voltage is required for corona discharge.

[0025] To this end, the technical solution is further improved: a mixed gas inlet 14 is further provided on the middle compartment 18, and the mixed gas inlet 14 is used to introduce the mixed gas into the middle compartment 18. In this embodiment, the mixed gas is composed of oxygen, nitrogen and argon, and the ratio of oxygen, nitrogen and argon is 3:5:1. The mixed gas can reduce the corona inception voltage and improve the oxidizability of the active particles.

[0026] From the above, it can be seen that the organic matter removal device has a membrane filter tube 21 and a corona discharge system. The membrane filter tube 21 can filter out large molecular organic matter in the mother liquor, and the active particles generated by the corona discharge system can oxidatively decompose small molecular organic matter in the mother liquor. After filtration by the membrane filter tube 21 and decomposition by corona discharge, 86-92% of the organic matter in the mother liquor can be removed, which greatly improves the comprehensive removal rate of organic matter.

[0027] Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. An organic matter removal device for Bayer alumina production, used for removing organic matter from mother liquor, characterized by: The organic matter removal device comprises a shell, in which an upper partition and a lower partition are arranged, the upper partition and the lower partition divide the space in the shell into an upper compartment, a middle compartment and a lower compartment, the upper compartment is provided with an outlet for concentrated organic matter liquid, the middle compartment is provided with an outlet for de-organic matter liquid, and the lower compartment is provided with an inlet for mother liquid; a plurality of connecting pipes are connected through the upper partition and the lower partition, and the upper compartment is connected with the lower compartment through the connecting pipes; the connecting pipes are composed of a membrane filter tube and a cathode tube, the membrane filter tube is connected above the cathode tube, and a corona discharge electrode is arranged outside the cathode tube.

2. The organic matter removal device for Bayer alumina production as claimed in claim 1, characterized in that: A positive tube is arranged outside the negative tube, and the corona discharge electrode array is arranged on the inner tube wall of the positive tube.

3. The organic matter removal device for Bayer alumina production as claimed in claim 2, characterized in that: The distance between the corona discharge electrode and the cathode tube is 5-15 mm.

4. The organic matter removal device for Bayer alumina production as claimed in claim 1, characterized in that: A mixed gas inlet is also provided on the middle partition cavity, and the mixed gas inlet is used to introduce the mixed gas into the middle partition cavity.

5. The organic matter removal device for Bayer alumina production as claimed in claim 1, characterized in that: The outer diameter of the negative electrode tube is larger than the outer diameter of the membrane filtration tube.

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