A continuous sodium removal system for alumina

Abstract

The utility model discloses a continuous type alumina sodium removal system, including the reaction tank, the acidification system of adding acid to the reaction tank and the chemical pulp system of adding the pulp liquid to the reaction tank, the reaction tank rotatable setting. Alumina sodium removal reaction, the reaction tank continues to rotate, makes the solid -liquid ratio of pulp liquid on the different elevation of reaction tank even, and the acid -base neutralization reaction speed is stable, and effectively shortens sodium removal work time. Realized from the chemical pulp, the acidification of the whole process of sodium removal continuous automation operation, solved the problem that the existing alumina sodium removal reaction needs the interval to carry out, reduced the labor intensity of worker, improved the efficiency of alumina sodium removal work.

Description

Technical Field

[0001] This utility model relates to the field of alumina production technology, specifically a continuous alumina sodium removal system. Background Technology

[0002] Sodium oxide content is one of the important technical indicators for evaluating the grade of high-temperature alumina. In the fields of wear-resistant products and ceramic applications, the sodium oxide content has a great influence on the mechanical strength and electrical conductivity of alumina products. How to reduce the sodium oxide content in high-temperature alumina has become one of the hot issues in the field of high-end alumina preparation.

[0003] One current method for producing low-sodium high-temperature alumina is to pretreat the alumina raw material by introducing acid through a wet process, using acid-base neutralization to remove sodium from the alumina, and then using hot water to wash away the salt generated in the reaction. After dehydration, drying and other processes, low-sodium alumina with a sodium content as low as 0.05% can be obtained.

[0004] For example, patent application number 201310448806.2, entitled "Invention Patent on a Method for High-Temperature Sodium Removal from Industrial Alumina," describes the following steps: Industrial alumina raw material, hydrochloric acid, and ammonium chloride are added to a container at a mass ratio of 100:(3-10):(3-8), with water added simultaneously. After thorough mixing, industrial alumina containing Cl- is obtained. The industrial alumina containing Cl- is then calcined. After cooling the calcined industrial alumina to room temperature, it is acid-washed to remove sodium under ultrasonic conditions. The acid-washed and ultrasonically treated alumina is washed with pure water for 1-2 hours until the pH reaches 7.0, at a washing temperature of 60-90℃. After drying, alumina containing 0.0002-0.0005% sodium is obtained.

[0005] However, the above scheme can only achieve intermittent sodium removal reaction, and cannot achieve stable and continuous sodium removal reaction, resulting in low sodium removal rate and production efficiency of alumina. Utility Model Content

[0006] The purpose of this invention is to solve the above-mentioned problems and provide a continuous alumina desodium removal system that realizes continuous automated operation of the entire process from pulping and acid preparation to desodium removal, thereby reducing the labor intensity of workers and improving the efficiency of alumina desodium removal.

[0007] The technical solution adopted by this utility model to solve its technical problem is: A continuous alumina sodium removal system includes a reaction tank, an acid addition system for adding acid to the reaction tank, and a slurry addition system for adding slurry to the reaction tank, wherein the reaction tank is rotatable.

[0008] Furthermore, the reaction vessels are arranged in multiple stages connected in series.

[0009] Furthermore, the inner wall of the reaction vessel is provided with several lifting plates for spreading and stirring the slurry.

[0010] Furthermore, the reaction vessel is a horizontal reaction vessel.

[0011] Furthermore, the journal of the reaction vessel is supported on a bearing seat by a bearing, and a motor is provided on the bearing seat. The motor drives the reaction vessel to rotate around its axis through a drive chain.

[0012] Furthermore, adjacent reaction vessels are connected by connecting pipes, and the journal is connected to the corresponding end of the connecting pipe via a swivel joint.

[0013] Furthermore, the pulping system includes a pulping tank, a powder metering feeding mechanism, a water metering feeding mechanism, and a stirring mechanism; The slurry tank includes a slurry mixing tank and a slurry equalization tank. A partition is provided between the slurry mixing tank and the slurry equalization tank. The slurry in the slurry equalization tank is transported to the reaction tank at the front end through a slurry delivery pipe.

[0014] Furthermore, the powder quantitative feeding mechanism includes a hopper disposed above the slurry mixing tank and a quantitative feeder disposed at the lower end of the hopper; The water metering feeding mechanism includes a water supply pipe, a water supply solenoid valve, a water volume regulating valve, and a flow meter installed on the water supply pipe; The stirring mechanism includes a slurry stirring motor and slurry stirring blades mounted on the output shaft of the slurry stirring motor.

[0015] Furthermore, the acid addition system includes an acid storage tank, an acid supply pipeline, an acid supply pump installed on the acid supply pipeline, an acid supply solenoid valve, and an acid quantity regulating valve.

[0016] Furthermore, the acid storage tank is equipped with an acid stirring motor, and the output end of the acid stirring motor is equipped with acid stirring blades.

[0017] Furthermore, the acid supply pipeline is connected to a branch pipeline, and the branch pipeline is equipped with a pressure regulating valve.

[0018] The beneficial effects of this utility model are: 1. This utility model includes a reaction tank, an acid addition system for adding acid to the reaction tank, and a slurry addition system for adding slurry to the reaction tank. The reaction tank is rotatable. During the sodium removal reaction of alumina, the reaction tank rotates continuously, ensuring a uniform solid-liquid ratio of the slurry at different elevations within the tank, stabilizing the acid-base neutralization reaction rate, and effectively shortening the sodium removal time. It achieves continuous automated operation of the entire process from slurry preparation and acid mixing to sodium removal, solving the problem of intermittent operation required in existing alumina sodium removal processes, reducing the labor intensity of workers, and improving the efficiency of alumina sodium removal.

[0019] 2. This utility model has several lifting plates on the inner wall of the reaction tank for spreading and stirring the slurry. The distribution and number of the lifting plates are not limited here and can be set according to actual needs. When the reaction tank rotates, the lifting plates spread and stir the slurry to improve the dispersibility of solid powder in the slurry and make the slurry concentration at each height layer in the reaction tank relatively stable.

[0020] 3. The reaction vessel in this utility model is a horizontal reaction vessel. The horizontal reaction vessel has a small elevation, and with the spreading and stirring effect of the lifting plates, it solves the problem of large solid-liquid ratio difference between the upper and lower parts of the vessel due to the large density difference between alumina powder and water in the vertical reaction vessel. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a side view of the reaction vessel of this utility model.

[0023] In the diagram: 1. Reaction tank; 2. Lifting plate; 3. Journal; 4. Bearing seat; 5. Motor; 6. Drive chain; 7. Connecting pipe; 8. Rotary joint; 9. Regulating valve; 10. Slurry outlet; 11. Acidity detection device; 12. Slurry mixing tank; 13. Equalization tank; 14. Baffle plate; 15. Slurry delivery pipe; 16. Slurry delivery pump; 17. Suction pipe; 18. Hopper; 19. Feeder; 20. Water supply pipe; 21. Water supply solenoid valve; 22. Water flow regulating valve; 23. Flow meter; 24. Slurry stirring motor; 25. Slurry stirring blades; 26. Acid storage tank; 27. Acid supply pipeline; 28. Acid supply pump; 29. ​​Acid supply solenoid valve; 30. Acid quantity regulating valve; 31. Check valve; 32. Filter; 33. Acid stirring motor; 34. Acid stirring blades; 35. Branch pipeline; 36. Pressure regulating valve. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0025] like Figure 1As shown, a continuous alumina sodium removal system includes a reaction tank 1, an acid addition system for adding acid to the reaction tank 1, and a slurry addition system for adding slurry to the reaction tank 1. The reaction tank 1 is rotatable. During the alumina sodium removal reaction, the reaction tank 1 rotates continuously, ensuring a uniform solid-liquid ratio of the slurry at different elevations within the reaction tank, stabilizing the acid-base neutralization reaction rate, and effectively shortening the sodium removal time. Previously, sodium removal reactions were carried out intermittently, meaning that after the slurry in the reaction tank was desodiumed, it was refilled for sodium removal. This application achieves continuous automated operation of the entire process from slurry preparation and acid mixing to sodium removal, solving the problem of intermittent operation in existing alumina sodium removal processes, reducing the labor intensity of workers, and improving the efficiency of alumina sodium removal.

[0026] like Figure 1 As shown, the reaction vessel 1 is arranged in multiple stages in series. Depending on the needs of sodium removal, the reaction vessel is not limited to the three stages shown in the figure, and multiple stages can be connected in series to meet the time required for the sodium removal reaction.

[0027] like Figure 1 As shown, the inner wall of the reaction tank 1 is provided with several lifting plates 2 for spreading and stirring the slurry. The distribution and number of the lifting plates 2 are not limited here and can be set according to actual needs. When the reaction tank rotates, the lifting plates spread and stir the slurry to improve the dispersibility of solid powder in the slurry and make the slurry concentration at each height layer in the reaction tank 1 relatively stable.

[0028] like Figure 1 As shown, the reaction vessel 1 is a horizontal reaction vessel. The horizontal reaction vessel has a lower elevation, and the spreading and stirring action of the lifting plates solves the problem of large solid-liquid ratio differences between the upper and lower parts of the vessel due to the large density difference between alumina powder and water, as seen in vertical reaction vessels.

[0029] like Figure 2 As shown, the journal 3 of the reaction vessel 1 is supported on the bearing seat 4 by a bearing. The bearing seat 4 is equipped with a motor 5, which drives the reaction vessel 1 to rotate around its axis via a drive chain 6. The reaction vessel 1 is driven by the motor 5 and the reducer via the drive chain 6. The output shaft of the motor 5 is equipped with a sprocket, and the outer cylindrical surface of the reaction vessel 1 is provided with a groove that mates with the drive chain 6. The drive chain 6 can be one of the following: a transmission belt, a transmission chain, a gear, a pin, or a friction drive. The reaction vessel 1 can also be directly driven by the motor 5 through several stages of pulleys, in which case the reducer can be omitted. The reaction vessel 1 can also be supported by a support roller, and the motor and the reducer drive the reaction vessel to rotate around its axis via the support roller. In this case, the bearing seat 4 and the journal 3 are no longer needed, and the rotary joint is directly connected to the reaction vessel 1 via a connecting pipe.

[0030] like Figure 1As shown, adjacent reaction tanks 1 are connected by connecting pipes 7, and the journal 3 is connected to the corresponding end of the connecting pipe 7 via a rotary joint 8. Adjusting valves 9 are provided on the connecting pipe 7 and at the slurry outlet 10 of the last reaction tank 1. The adjusting valves 9 can adjust the resistance of slurry discharge from each reaction tank, thereby adjusting the filling coefficient of the slurry in each reaction tank and ensuring that the slurry in the reaction tank is at a reasonable level.

[0031] like Figure 1 As shown, the slurry system includes a slurry tank, a powder metering feeding mechanism, a water metering feeding mechanism, and a stirring mechanism. The slurry tank includes a mixing tank 12 and a homogenizing tank 13. A partition 14 or a partition wall is provided between the mixing tank 12 and the homogenizing tank 13. The powder metering feeding mechanism adds powder to the mixing tank 12, and the water metering feeding mechanism adds water to the mixing tank 12. The stirring mechanism is used to stir the slurry in the mixing tank 12. The slurry in the mixing tank 12 overflows through the partition 14 and enters the homogenizing tank 13. The slurry in the homogenizing tank 13 is transported to the front reaction tank 1 through a slurry delivery pipe 15. A slurry delivery pump 16 is provided at the lower end of the slurry delivery pipe 15, and a suction pipe 17 that extends into the homogenizing tank 13 is provided at the output end of the slurry delivery pump 16. The upper end of the slurry delivery pipe 15 is connected to the journal of the front reaction tank 1.

[0032] like Figure 1 As shown, the powder quantitative feeding mechanism includes a hopper 18 disposed above the slurry mixing tank 12 and a quantitative feeder 19 disposed at the lower end of the hopper 18. The quantitative feeder 19 can be a screw feeder or a planetary feeder, etc., which is easy for those skilled in the art to think of, and will not be described in detail here. The quantitative feeder 19 uniformly and quantitatively feeds alumina powder according to the amount of powder required by the solid-liquid ratio of the slurry.

[0033] like Figure 1 As shown, the water metering feeding mechanism includes a water supply pipe 20, a water supply solenoid valve 21 installed on the water supply pipe 20, a water flow regulating valve 22, and a flow meter 23. A shut-off valve is also provided at the end of the water supply pipe 20. The shut-off valve is opened before the system starts running and closed after the system stops running. The water flow regulating valve, also known as a water flow control valve, is a device used to automatically or manually regulate the water flow in a pipeline. It is widely used in refrigeration, heating, domestic hot water, industrial processes and other fields. The flow meter is responsible for measuring the instantaneous flow or cumulative flow of water in the pipeline in real time.

[0034] like Figure 1 As shown, the stirring mechanism includes a slurry stirring motor 24 and slurry stirring blades 25 disposed on the output shaft of the slurry stirring motor 24. The stirring blades 25 penetrate into the slurry mixing tank 12 and rotate in the slurry mixing tank 12 to stir the slurry in the slurry mixing tank 12 evenly.

[0035] Before mixing the slurry, the slurry agitator motor 24 must be turned on, and the shut-off valve must be opened simultaneously to feed alumina powder into the hopper 18. During slurry mixing, the metering feeder 19 is turned on to uniformly and quantitatively feed alumina powder according to the amount of powder required for the solid-liquid ratio of the slurry. The powder is then fed into the mixing tank via the metering feeder 19. The water supply solenoid valve 21 is turned on, and the water flow regulating valve 22 is adjusted according to the water volume required for the solid-liquid ratio of the slurry to supply water to the mixing tank. The solid-liquid ratio of the slurry can be adjusted by adjusting the metering feeder 19 and the water flow regulating valve 22. The metering feeder 19 and the water supply solenoid valve 21 must be turned on synchronously to facilitate the adjustment and control of the solid-liquid ratio of the slurry. The alumina powder and water entering the mixing tank are agitated into a slurry by the slurry agitator blades 25 and then overflow through the baffle 14 into the homogenizing tank, thereby preventing insufficiently slurried raw material and liquid from entering the homogenizing tank and affecting the stability of the solid-liquid ratio of the slurry. The slurry entering the homogenization tank is pumped into the reaction tank 1 by the slurry pump 16 through the slurry pipe 15.

[0036] like Figure 1 As shown, the acid supply system includes an acid storage tank 26, an acid supply pipeline 27, an acid supply pump 28 installed on the acid supply pipeline 27, an acid supply solenoid valve 29, and an acid quantity regulating valve 30. The acid supply pipeline 27 is also equipped with a one-way valve 31. The lower end of the acid supply pipeline 27 extends into the acid storage tank 26, and a filter 32 is installed at the lower end of the acid supply pipeline 27. The other end of the acid supply pipeline 27 is connected to the slurry delivery pipe 15.

[0037] An acidity detection device 11 is also installed at the outlet 10 of the final reaction tank 1. The acid quantity regulating valve 30 is controlled by the acidity detection device 11 to achieve automatic control of the acid quantity.

[0038] The core task of an acidity detection device is to convert the acidity or alkalinity of a solution into a quantifiable and remotely transmit electrical signal.

[0039] like Figure 1 As shown, the acid storage tank 26 is equipped with an acid stirring motor 33, and the output end of the acid stirring motor 33 is equipped with acid stirring blades 34.

[0040] like Figure 1 As shown, a branch pipe 35 is connected to the acid supply pipe 27, and a pressure regulating valve 36 is provided on the branch pipe 35. The pressure regulating valve 36 plays a role in stabilizing pressure and overflowing, allowing excess acid in the acid supply pipe 27 to enter the acid storage tank 26 through the branch pipe.

[0041] Acid solution is added to the acid storage tank 26 and homogenized under the action of acid stirring motor 33 and acid stirring blades 34. The acid supply pump 28 is turned on, and the acid solution in the storage tank 26 passes through filter 32 into the acid supply pump 28 and is pumped into the acid supply pipeline 27, and then into the reaction tank 1. When the acid supply solenoid valve 29 is not working, the acid solution pumped by the acid supply pump 28 flows back to the acid storage tank 26 through the pressure regulating valve 36, and the acid supply pump 28 operates at the pressure set by the pressure regulating valve 36. When the acid supply solenoid valve 29 is turned on, part of the acid solution pumped by the acid supply pump 28 flows back to the acid storage tank 26 through the pressure regulating valve 36, and the acid supply pump 28 continues to operate at the pressure set by the pressure regulating valve 36. The other part of the acid solution is sent to the slurry delivery pipe 15 through the acid quantity regulating valve 30 and the one-way valve 31 to mix with the slurry. The acid quantity regulating valve 30 is controlled by the acidity detection device 11. It can automatically adjust the amount of acid fed into the slurry delivery pipe according to the acidity requirements of the neutralized slurry, thereby realizing the quantitative automatic control of the slurry and acid quantity.

[0042] Acid can also be injected into the slurry pipe by direct supply using a variable pump. In this case, the pressure regulating valve 36 and the acid quantity regulating valve 30 are no longer needed. The acid supply pump 28 is a variable pump, and the acid supply quantity can be directly adjusted by adjusting the flow rate of the acid supply pump 28. The acid supply quantity is still controlled by the acidity detection device 11 to achieve automatic control of the acid quantity.

[0043] The acid supply pump 28 and the slurry pump 16 need to be turned on simultaneously to facilitate the adjustment and control of the slurry and acid quantities.

[0044] After the slurry and acid are mixed in the slurry delivery pipe 15, they enter the primary reaction tank. While flowing forward in the reaction tank, they are simultaneously agitated by the lifting plates 2 on the inner wall of the tank, ensuring a more uniform dispersion of solids and liquids in the alumina slurry and guaranteeing a stable acid-base neutralization reaction rate. With the continuous feeding of slurry and acid, the slurry in the reaction tank flows from the inlet to the outlet, eventually exiting through a rotary joint, regulating valve, and connecting pipe into the secondary reaction tank. From there, it enters the tertiary reaction tank, until it is discharged from the slurry outlet, completing the continuous sodium removal process for alumina.

[0045] In the description of this utility model, it should be noted that the terms "left", "right", "up", "down", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0046] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A continuous alumina sodium removal system, comprising a reaction tank (1), an acid addition system for adding acid to the reaction tank (1), and a slurry addition system for adding slurry to the reaction tank (1), characterized in that, The reaction vessel (1) is rotatable.

2. The continuous alumina sodium removal system as described in claim 1, characterized in that, The reaction vessel (1) is arranged in multiple stages in series.

3. The continuous alumina sodium removal system as described in claim 1, characterized in that, The inner wall of the reaction vessel (1) is provided with several lifting plates (2) for spreading and stirring the slurry.

4. The continuous alumina sodium removal system as described in claim 1, characterized in that, The reaction vessel (1) is a horizontal reaction vessel.

5. The continuous alumina sodium removal system as described in claim 1, characterized in that, The journal (3) of the reaction vessel (1) is supported on the bearing seat (4) by the bearing. The bearing seat (4) is equipped with a motor (5). The motor (5) drives the reaction vessel (1) to rotate around its axis through the drive chain (6). The adjacent reaction vessels (1) are connected by a connecting pipe (7), and the journal (3) is connected to the corresponding end of the connecting pipe (7) by a rotary joint (8).

6. The continuous alumina sodium removal system as described in claim 1, characterized in that, The pulping system includes a pulping tank, a powder metering feeding mechanism, a water metering feeding mechanism, and a mixing mechanism; The slurry tank includes a slurry mixing tank (12) and a slurry equalization tank (13). A partition (14) is provided between the slurry mixing tank (12) and the slurry equalization tank (13). The slurry in the slurry equalization tank (13) is transported to the reaction tank (1) at the front end through a slurry delivery pipe (15).

7. A continuous alumina sodium removal system as described in claim 6, characterized in that, The powder quantitative feeding mechanism includes a hopper (18) located above the mixing tank (12) and a quantitative feeder (19) located at the lower end of the hopper (18). The water metering feeding mechanism includes a water supply pipe (20), a water supply solenoid valve (21) installed on the water supply pipe (20), a water volume regulating valve (22), and a flow meter (23). The stirring mechanism includes a slurry stirring motor (24) and slurry stirring blades (25) disposed on the output shaft of the slurry stirring motor (24).

8. The continuous alumina sodium removal system as described in claim 1, characterized in that, The acid addition system includes an acid storage tank (26), an acid supply pipeline (27), an acid supply pump (28) installed on the acid supply pipeline (27), an acid supply solenoid valve (29), and an acid quantity regulating valve (30).

9. A continuous alumina sodium removal system as described in claim 8, characterized in that, The acid storage tank (26) is equipped with an acid stirring motor (33), and the output end of the acid stirring motor (33) is equipped with acid stirring blades (34).

10. A continuous alumina sodium removal system as described in claim 8, characterized in that, A branch pipeline (35) is connected to the acid supply pipeline (27), and a pressure regulating valve (36) is provided on the branch pipeline (35).

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