Organic matter removal and cooling tank for alumina decomposition

Abstract

This utility model relates to the field of alumina decomposition technology, and proposes a cooling tank for removing organic matter during alumina decomposition. The tank includes: a plate heat exchanger body, with a mother liquor channel and a circulating water channel inside; a high-temperature mother liquor inlet pipe, a high-temperature mother liquor outlet pipe, a circulating water inlet pipe, and a circulating water outlet pipe at one end of the plate heat exchanger body, both connected to the mother liquor channel; and a cooling tank, with a mother liquor inlet pipe fixedly connected to one end; and a coil inside the cooling tank, with a circulating water inlet pipe and a circulating water return pipe fixedly connected to both ends of the coil. This technical solution solves the problem in existing technologies where it is difficult to control the inflow rate and temperature of the low-temperature mother liquor according to the needs of alumina decomposition, leading to potential deviations in product quality.

Description

Technical Field

[0001] This utility model relates to the field of alumina decomposition technology, specifically to an organic matter removal and cooling tank for alumina decomposition. Background Technology

[0002] Natural aluminum ore contains organic matter such as plant roots and stems collected during mining. As the ore is leached and decomposed, the organic matter is transformed into oxalate components, especially sodium oxalate. Sodium oxalate interferes with the agglomeration process of aluminum hydroxide, affecting the particle size and strength of the finished alumina. Moreover, the accumulation of oxalate in the production equipment can easily lead to equipment scaling, increasing the difficulty of equipment cleaning and maintenance costs.

[0003] In response to this problem, various alumina manufacturers have conducted a variety of studies on the removal of organic impurities during the alumina production process. Currently used methods for removing organic matter include calcination oxidation, wet oxidation, ion exchange, activated carbon adsorption, and crystallization.

[0004] Calcination oxidation and wet oxidation decompose organic matter into inorganic matter such as carbon dioxide through calcination or oxygen oxidation. However, the high-temperature reaction conditions result in high energy consumption, high equipment requirements, and complex processes. Ion exchange and activated carbon adsorption methods use ion exchange membranes or activated carbon to adsorb and enrich organic matter, thereby removing organic matter from the alumina production system. However, the regeneration of resin membranes and activated carbon is difficult and their reusability is poor, which leads to increased material costs and higher production costs.

[0005] Crystallization is currently the most commonly used method for industrial alumina production. It utilizes the lower solubility of oxalate compared to alumina to lower the temperature of the alumina solution to a suitable range, causing oxalate to crystallize and precipitate. The process is simple and energy-efficient. However, the cooling tank where oxalate crystallization occurs has poor temperature control. Wide-channel plate heat exchangers are often used for initial cooling of the high-temperature alumina mother liquor. However, traditional wide-channel plate heat exchangers have excessively fast heat exchange rates and limited temperature adjustment range. The high-concentration, high-temperature mother liquor from the evaporation section cools too quickly in the wide-channel plate heat exchanger, causing the oxalate organic matter to crystallize and precipitate directly at the wide-channel plate heat exchanger before reaching the designated cooling tank. This easily leads to scaling on the wide-channel plate heat exchanger equipment, and the oxalate crystals cannot be collected at specific points, easily mixing into the finished alumina product and degrading its quality. To address this, a common approach is to reduce the cooling amplitude of the alumina mother liquor at the wide-channel plate heat exchanger and increase the cooling amplitude in the cooling tank, allowing the oxalate to crystallize and precipitate in the designated cooling tank after passing through the wide-channel plate heat exchanger in a solution state.

[0006] However, in the application of the circulating water pipeline of the cooling tank in the traditional technology, it is difficult to control the inlet flow rate and temperature of the low temperature mother liquor according to the decomposition requirements of alumina, which makes the product quality prone to deviation.

[0007] Based on this, we propose a cooling tank for removing organic matter during alumina decomposition. Utility Model Content

[0008] This invention proposes an organic matter removal and cooling tank for alumina decomposition, which solves the problem in related technologies that it is difficult to control the influent flow rate and temperature of the low-temperature mother liquor according to the decomposition requirements of alumina, which makes the product quality prone to deviation.

[0009] The technical solution of this utility model is as follows: a cooling tank for removing organic matter from alumina decomposition, comprising:

[0010] The plate heat exchanger body has a mother liquor flow channel and a circulating water flow channel inside. One end of the plate heat exchanger body is provided with a high-temperature mother liquor inlet pipe, a high-temperature mother liquor outlet pipe, a circulating water inlet pipe, and a circulating water outlet pipe. The high-temperature mother liquor inlet pipe and the high-temperature mother liquor outlet pipe are both connected to the mother liquor flow channel, and the circulating water inlet pipe and the circulating water outlet pipe are both connected to the circulating water flow channel.

[0011] A cooling tank is provided, with a mother liquor inlet pipe fixedly connected to one end. A coil is installed inside the cooling tank, and a circulating water inlet pipe and a circulating water return pipe are fixedly connected to both ends of the coil, respectively. The high-temperature mother liquor outlet pipe and the mother liquor inlet pipe are connected through a transmission pipe A, and the circulating water outlet pipe and the circulating water inlet pipe are connected through a transmission pipe B.

[0012] A liquid supply assembly is disposed between the circulating water inlet pipe and the circulating water outlet pipe;

[0013] The control center is located on one side of the cooling tank. The control center is used to supplement circulating water into the circulating water channel and coil in conjunction with the circulating water inlet pipe and the circulating water outlet pipe.

[0014] Preferably, the liquid supply assembly includes a main liquid supply pipe, one end of which is fixedly connected to a delivery pipe, and the end of the delivery pipe away from the main liquid supply pipe is connected to a circulating water inlet pipe. Delivery pipes A and B are fixedly connected to both ends of the main liquid supply pipe, respectively. The end of delivery pipe A away from the main liquid supply pipe is connected to the connection point of the delivery pipe and the circulating water inlet pipe, and the end of delivery pipe B away from the main liquid supply pipe is connected to the connection point of the transmission pipe B and the circulating water inlet pipe. Both delivery pipe A and delivery pipe B are equipped with a solenoid valve, a temperature sensor, and a flow sensor.

[0015] Preferably, the control center includes a housing, a DCS controller, a heat dissipation window, and a filter plate. The housing is fixedly connected to one side of the cooling tank, and the DCS controller is fixedly connected inside the housing. Heat dissipation windows are embedded at both ends of the housing, and filter plates are installed inside the heat dissipation windows. Multiple limiting shafts are provided at both ends of the housing, and a baffle for blocking the filter plate is fixedly connected to the outside of each limiting shaft.

[0016] Preferably, an electromagnetic control valve is provided on the outside of the high-temperature mother liquor inlet pipe.

[0017] Preferably, the electromagnetic control valve, the solenoid valve, the temperature sensor, and the flow sensor are all electrically connected to the DCS controller.

[0018] Preferably, the heat dissipation window is located on the inner wall of the housing and is fixedly connected to a retaining ring, and a sealing strip is fixedly connected to the retaining ring.

[0019] Preferably, the DCS controller has mounting holes at both ends, and the limiting shaft is installed in the corresponding mounting hole and has a transition fit with the mounting hole.

[0020] Preferably, one end of the limiting shaft is fixedly connected to a force-bearing knob, and the outer side of the force-bearing knob is provided with anti-slip texture.

[0021] The working principle and beneficial effects of this utility model are as follows:

[0022] 1. This utility model optimizes the mother liquor path of the cooling tank through the design of a two-stage cooling circulating water pipeline system, increases the inlet flow rate of the low-temperature mother liquor, improves the degree of automated inlet control, and enhances product quality and production efficiency.

[0023] 2. This utility model is based on DCS-based oxalate crystallization temperature control technology, which reduces energy consumption costs, improves the temperature regulation of the cooling tank, enhances the removal effect of organic matter, improves the particle size and strength quality of alumina, and extends the service life of the equipment. Attached Figure Description

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a side view of the structure of this utility model;

[0027] Figure 3 This is a schematic diagram of the liquid supply component of this utility model;

[0028] Figure 4This is a schematic diagram of the control center of this utility model;

[0029] Figure 5 This utility model Figure 4 A magnified view of a portion of point A in the middle.

[0030] In the diagram: 1. Plate heat exchanger body; 2. High-temperature mother liquor inlet pipe; 3. High-temperature mother liquor outlet pipe; 4. Circulating water inlet pipe; 5. Circulating water outlet pipe; 6. Cooling tank; 7. Mother liquor inlet pipe; 8. Circulating water inlet pipe; 9. Circulating water return pipe; 10. Transmission pipe A; 11. Transmission pipe B; 12. Control center; 13. Main liquid supply pipe; 14. Delivery pipe; 15. Liquid delivery pipe A; 16. Liquid delivery pipe B; 17. Solenoid valve; 18. Temperature sensor; 19. Flow sensor; 20. Mounting shell; 21. DCS controller; 22. Heat dissipation window; 23. Filter plate; 24. Limiting shaft; 25. Baffle plate. Detailed Implementation

[0031] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. 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 of ordinary skill in the art without creative effort are within the scope of protection of this utility model.

[0032] Example 1

[0033] like Figures 1-5 As shown, this embodiment proposes a cooling tank for removing organic matter during alumina decomposition, comprising:

[0034] The plate heat exchanger body 1 has a mother liquor flow channel and a circulating water flow channel inside. One end of the plate heat exchanger body 1 is provided with a high-temperature mother liquor inlet pipe 2, a high-temperature mother liquor outlet pipe 3, a circulating water inlet pipe 4, and a circulating water outlet pipe 5. The high-temperature mother liquor inlet pipe 2 and the high-temperature mother liquor outlet pipe 3 are both connected to the mother liquor flow channel, and the circulating water inlet pipe 4 and the circulating water outlet pipe 5 are both connected to the circulating water flow channel.

[0035] Cooling tank 6, with a mother liquor inlet pipe 7 fixedly connected to one end of the cooling tank 6, a coil installed inside the cooling tank 6, and a circulating water inlet pipe 8 and a circulating water return pipe 9 fixedly connected to both ends of the coil respectively, the high temperature mother liquor outlet pipe 3 and the mother liquor inlet pipe 7 are connected by a transmission pipe A10, and the circulating water outlet pipe 5 and the circulating water inlet pipe 8 are connected by a transmission pipe B11.

[0036] Liquid supply assembly, which is installed between circulating water inlet pipe 8 and circulating water outlet pipe 4;

[0037] Control center 12 is located on one side of cooling tank 6. Control center 12 is used to supplement circulating water to the circulating water channel and coil in conjunction with circulating water inlet pipe 4 and circulating water inlet pipe 8.

[0038] In detail, an electromagnetic control valve is installed on the outside of the high-temperature mother liquor inlet pipe 2. By using the electromagnetic control valve, the on / off state of the high-temperature mother liquor inlet pipe 2 can be effectively controlled, making the amount of high-temperature mother liquor introduced more controllable.

[0039] The liquid supply assembly includes a main liquid supply pipe 13, one end of which is fixedly connected to a delivery pipe 14, and the end of the delivery pipe 14 away from the main liquid supply pipe 13 is connected to a circulating water inlet pipe 4. The two ends of the main liquid supply pipe 13 are respectively fixedly connected to a delivery pipe A15 and a delivery pipe B16. The end of the delivery pipe A15 away from the main liquid supply pipe 13 is connected to the connection between the delivery pipe 14 and the circulating water inlet pipe 4, and the end of the delivery pipe B16 away from the main liquid supply pipe 13 is connected to the connection between the transmission pipe B11 and the circulating water inlet pipe 8. A solenoid valve 17, a temperature sensor 18, and a flow sensor 19 are provided on both the delivery pipe A15 and the delivery pipe B16.

[0040] In this embodiment, the slope of the liquid delivery pipe A15 between the liquid supply main pipe 13 and the circulating water inlet pipe 4, and the slope of the liquid delivery pipe B16 between the liquid supply main pipe 13 and the circulating water inlet pipe 8, are both approximately 0.003, in order to enhance the flow of circulating water within a safe range, and the liquid delivery pipes A15 and B16 can be connected by flanges.

[0041] Example 2

[0042] like Figures 1-5 As shown, based on the same concept as Embodiment 1 above, this embodiment also proposes a control center 12;

[0043] In this embodiment, the control center 12 includes a housing 20, a DCS controller 21, a heat dissipation window 22, and a filter plate 23. The housing 20 is fixedly connected to one side of the cooling tank 6. The DCS controller 21 is fixedly connected inside the housing 20. Heat dissipation windows 22 are embedded at both ends of the housing 20. The filter plate 23 is disposed inside the heat dissipation window 22. Multiple limiting shafts 24 are disposed at both ends of the housing 20. A baffle 25 for blocking the filter plate 23 is fixedly connected to the outside of each limiting shaft 24.

[0044] In detail, the electromagnetic control valve, solenoid valve 17, temperature sensor 18 and flow sensor 19 are all electrically connected to the DCS controller 21. Through the settings of the DCS controller 21, the electromagnetic control valve, solenoid valve 17, temperature sensor 18 and flow sensor 19 can be centrally controlled, which greatly improves the convenience of the overall application.

[0045] The DCS controller 21 is a new generation of instrument control system based on a microprocessor. It employs a design principle that combines distributed control functions with centralized display and operation, balancing autonomy and comprehensive coordination. Control functions are distributed across multiple independent control units, each responsible for a portion of the control tasks. This distributed design improves system reliability and flexibility; even if one control unit fails, it will not affect the operation of the entire system. This is a mature existing technology and will not be elaborated further here.

[0046] In detail, the heat dissipation window 22 is fixedly connected to the inner wall of the housing 20 with a retaining ring, and a sealing strip is fixedly connected to the retaining ring. With the setting of the retaining ring, after the filter plate 23 is placed, the retaining ring can block the filter plate 23 and prevent the filter plate 23 from falling into the housing 20. In addition, with the setting of the sealing strip, the gap between the filter plate 23 and the retaining ring can be sealed to prevent dust from entering the housing 20 from the gap.

[0047] In detail, both ends of the DCS controller 21 are provided with mounting holes. The limit shaft 24 is installed in the corresponding mounting hole and is transitionally fitted with the mounting hole. The mounting hole can effectively support the limit shaft 24. In addition, the connection between the limit shaft 24 and the mounting hole can limit the rotation of the limit shaft 24, thereby locking the position of the baffle 25.

[0048] In detail, a force-bearing knob is fixedly connected to one end of the limiting shaft 24, and the outer side of the force-bearing knob is provided with anti-slip texture. The force-bearing knob allows the operator to rotate the limiting shaft 24 with less effort, ensuring the transmission effect of the limiting shaft 24.

[0049] A specific application of the above two embodiments is as follows: when the high-concentration mother liquor from evaporation flows through the plate heat exchanger body 1, the DCS controller 21 adjusts the opening and closing of the solenoid valve 17 at the liquid delivery pipe A15 to regulate the low-temperature liquid inlet flow rate, thereby initially and significantly cooling the high-concentration mother liquor to a temperature range slightly higher than that of oxalate crystallization. After the initial significant cooling, the high-concentration mother liquor flows into the cooling tank 6 through the transmission pipe A10. The DCS controller 21 then precisely adjusts the cooling rate of the cooling tank 6 by controlling the opening and closing of the solenoid valve 17 at the liquid delivery pipe B16 based on the temperature sensor 18 and the real-time monitoring values ​​of the temperature sensor 18. This ensures that when the temperature drops to the oxalate crystallization temperature, oxalate enters the cooling tank 6 and crystallizes out, achieving accurate point collection of oxalate. The entire process is independently controlled by the DCS system controller of the decomposition process, resulting in good oxalate removal and a significant reduction in the content of organic impurities in the alumina mother liquor, which is beneficial to improving the quality of alumina products.

[0050] Furthermore, the heat generated during the operation of the DCS controller 21 can be dissipated through the heat dissipation window 22, and the filter plate 23 can prevent dust and other debris from adhering to the DCS controller 21. When the filter plate 23 is not effective, first rotate the limit shaft 24 to make the baffle 25 move away from the filter plate 23. After the baffle 25 is removed from the filter plate 23, the limit on the filter plate 23 can be released, and then the filter plate 23 can be removed and replaced.

[0051] In summary, by optimizing the inlet and outlet water paths between the cooling tank 6 and the plate heat exchanger body 1, and by using solenoid valve 17 to automatically control the inlet flow rate of the newly added low-temperature circulating water pipeline, the two-step low-temperature conditions required for oxalate to cool down at the plate heat exchanger body 1 and crystallize and precipitate at the cooling tank 6 are met. This further improves the systematic and stable removal effect of organic matter, increases the amount of organic matter removed from the production system, improves the quality of alumina products, and increases the production efficiency of the enterprise.

[0052] Meanwhile, the DCS control method is used to adjust the circulating water temperature of the cooling tank 6 in a timely manner, so that the oxalate in the alumina solution system crystallizes and precipitates to the maximum extent in the designated cooling tank 6, thereby reducing the impact on the particle size and strength of the finished alumina product and the equipment scaling damage to the plate heat exchanger body 1.

[0053] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A cooling tank for removing organic matter during alumina decomposition, characterized in that, include: The plate heat exchanger body (1) has a mother liquor channel and a circulating water channel inside. One end of the plate heat exchanger body (1) is provided with a high-temperature mother liquor inlet pipe (2), a high-temperature mother liquor outlet pipe (3), a circulating water inlet pipe (4), and a circulating water outlet pipe (5). The high-temperature mother liquor inlet pipe (2) and the high-temperature mother liquor outlet pipe (3) are both connected to the mother liquor channel. The circulating water inlet pipe (4) and the circulating water outlet pipe (5) are both connected to the circulating water channel. Cooling tank (6), one end of which is fixedly connected to mother liquor inlet pipe (7), the inside of the cooling tank (6) is provided with coil, and the two ends of the coil are respectively fixedly connected to circulating water inlet pipe (8) and circulating water return pipe (9), the high temperature mother liquor outlet pipe (3) and mother liquor inlet pipe (7) are connected through transmission pipe A (10), and the circulating water outlet pipe (5) and circulating water inlet pipe (8) are connected through transmission pipe B (11); Liquid supply assembly, wherein the liquid supply assembly is disposed between the circulating water inlet pipe (8) and the circulating water inlet pipe (4); The control center (12) is located on one side of the cooling tank (6). The control center (12) is used to supplement circulating water into the circulating water channel and the coil in conjunction with the circulating water inlet pipe (4) and the circulating water inlet pipe (8).

2. The cooling tank for removing organic matter from alumina decomposition according to claim 1, characterized in that, The liquid supply assembly includes a liquid supply main pipe (13), one end of which is fixedly connected to a delivery pipe (14), and the end of the delivery pipe (14) away from the liquid supply main pipe (13) is connected to a circulating water inlet pipe (4). The two ends of the liquid supply main pipe (13) are respectively fixedly connected to a delivery pipe A (15) and a delivery pipe B (16). The end of the delivery pipe A (15) away from the liquid supply main pipe (13) is connected to the connection between the delivery pipe (14) and the circulating water inlet pipe (4). The end of the delivery pipe B (16) away from the liquid supply main pipe (13) is connected to the connection between the transmission pipe B (11) and the circulating water inlet pipe (8). Both the delivery pipe A (15) and the delivery pipe B (16) are equipped with a solenoid valve (17), a temperature sensor (18), and a flow sensor (19).

3. The cooling tank for removing organic matter from alumina decomposition according to claim 1, characterized in that, The control center (12) includes a housing (20), a DCS controller (21), a heat dissipation window (22), and a filter plate (23). The housing (20) is fixedly connected to one side of the cooling tank (6). The DCS controller (21) is fixedly connected inside the housing (20). Heat dissipation windows (22) are embedded at both ends of the housing (20). The filter plate (23) is installed inside the heat dissipation window (22). Multiple limiting shafts (24) are provided at both ends of the housing (20). A baffle (25) for blocking the filter plate (23) is fixedly connected to the outside of each limiting shaft (24).

4. The cooling tank for removing organic matter from alumina decomposition according to claim 1, characterized in that, An electromagnetic control valve is provided on the outside of the high-temperature mother liquor inlet pipe (2).

5. The cooling tank for removing organic matter from alumina decomposition according to claim 4, characterized in that, The electromagnetic control valve, solenoid valve (17), temperature sensor (18) and flow sensor (19) are all electrically connected to the DCS controller (21).

6. The cooling tank for removing organic matter from alumina decomposition according to claim 3, characterized in that, The heat dissipation window (22) is located on the inner wall of the housing (20) and is fixedly connected to a retaining ring, and a sealing strip is fixedly connected to the retaining ring.

7. The cooling tank for removing organic matter from alumina decomposition according to claim 3, characterized in that, The DCS controller (21) has assembly holes at both ends, and the limiting shaft (24) is installed in the corresponding assembly hole and has a transition fit with the assembly hole.

8. The cooling tank for removing organic matter from alumina decomposition according to claim 7, characterized in that, One end of the limiting shaft (24) is fixedly connected to a force-bearing knob, and the outer side of the force-bearing knob is provided with anti-slip texture.

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