Salt mud washing and desalting system
By combining a settling tank, a filter press, and a washing water supply pipe, the problems of low sodium chloride washing efficiency and high water consumption in salt mud are solved, achieving efficient salt mud washing and water conservation, and meeting the requirements of cement production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 四川永祥树脂有限公司
- Filing Date
- 2025-05-07
- Publication Date
- 2026-04-28
AI Technical Summary
Existing technologies have low efficiency in washing sodium chloride from salt mud, making it difficult to reduce its content, which affects the quality of cement production. Furthermore, they consume a large amount of water and have high energy consumption.
A combined system consisting of a settling tank, a primary filter press, a sludge washing tank, and a washing water supply pipe is adopted. Through settling, concentration, clarification, washing, and dilution, the washing water volume is precisely controlled by a flow meter and a flow regulating valve to improve the dissolution effect of salt sludge.
It improves the washing efficiency of salt mud, reduces the sodium chloride content in salt mud to meet the requirements of cement production, reduces water consumption, and lowers energy consumption.
Smart Images
Figure CN224172680U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of primary brine refining process in ion-exchange membrane caustic soda electrolysis, and in particular to a salt mud washing and desalination system. Background Technology
[0002] The primary brine refining process in the ion-exchange membrane caustic soda electrolysis step mainly involves pretreating the crude brine to remove impurities, yielding primary refined brine (which, after secondary refining, becomes secondary refined brine), providing qualified raw materials for subsequent electrolysis processes. The primary brine refining process in the ion-exchange membrane caustic soda electrolysis step includes: dissolving raw salt in water and adding barium chloride to remove sulfate ions, forming crude brine; as the crude brine passes through a pre-processor and membrane filter, refining agents such as sodium hydroxide are added, and the brine is then neutralized with hydrochloric acid through a dry salt saturation system to become primary refined brine.
[0003] In the primary brine refining process of ion-exchange membrane caustic soda electrolysis, the salt mud separated from the primary refined brine typically contains approximately 8% sodium chloride, approximately 60% calcium carbonate, and approximately 6% magnesium hydroxide. This salt mud is transported to cement plants as a raw material for cement production. In existing technology, the salt mud is usually washed with water in a filter press to remove sodium chloride. However, this method has the following drawbacks:
[0004] 1. During the filter press process, it is difficult to dissolve and wash out the sodium chloride in the salt mud when water is added for washing. The washing efficiency is low and it is difficult to effectively reduce the sodium chloride content in the salt mud. The high chloride ion content in the salt mud will have an adverse effect on cement production and reduce the quality of cement.
[0005] 2. When adding water for washing during the filter press process, a large amount of water is required, which will lead to excessive water addition to the system and increase energy consumption. Utility Model Content
[0006] In view of the above situation, the present invention provides a salt mud washing and desalination system, which aims to solve at least one of the defects pointed out in the background art.
[0007] To achieve the above objectives, this utility model provides the following technical solution:
[0008] This utility model provides a salt mud washing and desalination system, comprising:
[0009] The settling tank has a salt mud solution inlet at the top and a salt mud outlet at the bottom.
[0010] The primary filter press has its inlet connected to the salt mud outlet.
[0011] The sludge washing tank has its inlet connected to the solid phase outlet of the primary filter press;
[0012] The washing water supply pipe is used to supply washing water to the sludge washing tank; the washing water supply pipe is equipped with an associated flow meter and flow regulating valve.
[0013] In some embodiments of this utility model, the upper part of the settling tank has a supernatant outlet, and the supernatant outlet is connected to a concentrated brine tank.
[0014] In some embodiments of this utility model, the outlet of the concentrated brine tank is connected to the front end of the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process.
[0015] In some embodiments of this invention, the liquid phase outlet of the primary filter press is connected to the inlet of the concentrated brine tank.
[0016] In some embodiments of this utility model, the settling tank is an inclined plate settling tank.
[0017] In some embodiments of this utility model, the mud washing tank is equipped with a stirring device.
[0018] In some embodiments of this utility model, the temperature of the washing water is 40~60℃.
[0019] In some embodiments of this utility model, a two-stage filter press is connected to the outlet of the sludge washing tank.
[0020] In some embodiments of this utility model, the liquid phase outlet of the secondary filter press is connected to a brine tank.
[0021] In some embodiments of this utility model, the outlet of the salt water tank is connected to the washing water supply pipe.
[0022] The embodiments of this utility model have at least the following advantages or beneficial effects:
[0023] By using a settling tank, a primary filter press, a sludge washing tank, and a washing water supply pipe, the salt mud solution is first concentrated and clarified in the settling tank, increasing the solids content of the feed liquid to the primary filter press and improving the efficiency of the filter press treatment. Then, the filter cake obtained after filtration by the primary filter press is dissolved, washed, and diluted through the sludge washing tank and the washing water supply pipe. Since the weight of the filter cake discharged by the primary filter press is basically stable each time it works, the amount of washing water required for washing and dilution can be accurately calculated. Combined with the setting of flow meters and flow regulating valves, the amount of washing water in the sludge washing tank can be precisely controlled. This avoids adding too much washing water to the system and effectively controls the solids content of the salt mud in the sludge washing tank, which facilitates the dissolution effect of the salt mud. After being washed, dissolved, and diluted, the salt content of the salt mud in the sludge washing tank is less than 1%, which meets the requirements for cement production and can be used to produce qualified cement.
[0024] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 A schematic diagram of a salt mud washing and desalination system.
[0027] icon:
[0028] 1-Salt mud pond,
[0029] 2-Settling tank, 21-Salt mud solution inlet, 22-Supernatant outlet, 23-Salt mud outlet.
[0030] 3-Concentrated brine tank, 31-Outlet of concentrated brine tank,
[0031] 4- Primary filter press,
[0032] 5-Sludge washing tank, 51-Mixing device,
[0033] 6-Washing water supply pipe, 61-Flow meter, 62-Flow regulating valve,
[0034] 7-Secondary filter press, 71-Discharge hopper
[0035] 8 - Saltwater tank; 81 - Outlet of saltwater tank. Detailed Implementation
[0036] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention.
[0037] In the description of the embodiments of this utility model, it should be understood that the terms "upper", "lower", "inner", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of 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 the embodiments of this utility model.
[0038] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.
[0039] The embodiments of this utility model will be described in detail below.
[0040] Example
[0041] See Figure 1 This embodiment provides a salt mud washing and desalination system, including a salt mud tank 1, a settling tank 2, a concentrated brine tank 3, a primary filter press 4, a mud washing tank 5, a washing water supply pipe 6, a secondary filter press 7, and a dilute brine tank 8.
[0042] Salt mud tank 1 is used to store salt mud solution from the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process. Salt mud tank 1 is equipped with a stirring structure.
[0043] The settling tank 2 has a salt mud solution inlet 21 and a supernatant outlet 22 at the top, and a salt mud outlet 23 at the bottom. The salt mud solution inlet 21 of the settling tank 2 is connected to the salt mud pool 1 via a salt mud pump, which pumps the salt mud solution into the settling tank 2. The settling tank 2 is an inclined plate type settling tank, which uses the principle of shallow sedimentation to treat the salt mud solution. A supernatant is obtained at the top of the settling tank 2, and a salt mud with a high solids content (10~15%) is obtained at the bottom. The supernatant is concentrated brine.
[0044] The inlet of the concentrated brine tank 3 is connected to the supernatant outlet 22. The concentrated brine in the settling tank 2 is discharged from the supernatant outlet 22 and enters the concentrated brine tank 3. The outlet 31 of the concentrated brine tank is connected to the front end of the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process, and the concentrated brine in the concentrated brine tank 3 is sent back to the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process to be mixed with the crude brine.
[0045] The feed inlet of the primary filter press 4 is connected to the salt mud outlet 23 of the settling tank 2; the solid phase outlet of the primary filter press 4 is connected to the inlet of the sludge washing tank 5, and the solid phase outlet of the primary filter press 4 is located above the sludge washing tank 5, so that the filter cake discharged from the solid phase outlet of the primary filter press 4 falls into the sludge washing tank 5; the liquid phase outlet of the primary filter press 4 is connected to the inlet of the concentrated brine tank 3, so that the filtrate discharged from the primary filter press 4 enters the concentrated brine tank 3. In a specific implementation scenario, two primary filter presses 4 are connected in parallel.
[0046] The mud washing tank 5 is equipped with a stirring device 51.
[0047] The washing water supply pipe 6 is connected to the inlet of the sludge washing tank 5 and is used to supply washing water (lightly salted water) to the sludge washing tank 5. The temperature of the washing water is 40~60℃. The washing water supply pipe 6 is equipped with an associated flow meter 61 and a flow regulating valve 62. The flow meter 61 is used to detect the real-time flow in the washing water supply pipe 6, and the flow regulating valve 62 adjusts the opening degree according to the real-time flow in the washing water supply pipe 6 so that the flow in the washing water supply pipe 6 reaches the expected value.
[0048] The inlet of the secondary filter press 7 is connected to the outlet of the sludge washing tank 5 via a secondary filter press pump. A discharge hopper 71 is provided below the solid phase outlet of the secondary filter press 7, and the filter cake discharged from the secondary filter press 7 falls into the discharge hopper 71; the brine is discharged from the liquid phase outlet of the secondary filter press 7.
[0049] The inlet of the brine tank 8 is connected to the liquid phase outlet of the secondary filter press 7 and is used to store brine. The brine stored in the brine tank 8 can be sent back to the mud washing tank 5 as washing water through the washing water supply pipe 6 (the outlet 81 of the brine tank is connected to the washing water supply pipe 6, and the flow rate of the outlet 81 of the brine tank is adjustable), or it can be used for salt treatment or brine injection wells.
[0050] The salt mud solution from the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process is stored in salt mud tank 1. The solution is then pumped to settling tank 2, where it is concentrated and clarified. A supernatant is obtained at the top of the settling tank, and salt mud with a high solids content (10-15%) is obtained at the bottom. This salt mud is then pumped to a primary filter press 4. The filter cake discharged from the primary filter press 4 falls into a washing tank 5. Because the weight of the filter cake discharged from the primary filter press 4 is relatively stable each time it operates, the amount of washing water required for washing and dilution can be accurately calculated. By adjusting the water volume and using the flow meter 61 and flow regulating valve 62, the amount of washing water in the sludge washing tank 5 can be precisely controlled. This avoids adding too much washing water to the system while effectively controlling the solid content of the sludge washing tank 5, which facilitates the dissolution of salt mud and makes it easier to pump it to the secondary filter press 7. After the salt mud in the sludge washing tank 5 is washed and diluted, the salt content is less than 1%, which meets the requirements for cement production and can be used to produce qualified cement. Under the pressure of the secondary filter press 7, the brine obtained is stored in the brine tank 8.
[0051] The brine stored in the brine tank 8 can be returned to the mud washing tank 5 as washing water through the washing water supply pipe 6, or used for salt treatment and brine injection. The filtrate obtained from the primary filter press 4 enters the concentrated brine tank 3, and the supernatant in the settling tank 2 also enters the concentrated brine tank 3. Part of the concentrated brine in the concentrated brine tank 3 is pumped back to the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process to mix with the crude brine, while the other part of the concentrated brine is pumped back to the primary filter press 4 for filter pressing.
[0052] In summary, this embodiment has at least the following beneficial effects:
[0053] 1. By setting up a settling tank 2, a primary filter press 4, a sludge washing tank 5, and a washing water supply pipe 6, the salt mud solution is first concentrated and clarified in the settling tank 2, increasing the solids content of the feed liquid to the primary filter press 4 and improving the efficiency of the filter press treatment. Then, the filter cake obtained after filtration by the primary filter press 4 is dissolved, washed, and diluted through the sludge washing tank 5 and the washing water supply pipe 6. Since the weight of the filter cake discharged by the primary filter press 4 is basically stable each time it works, the amount of washing water required for washing and dilution can be accurately calculated. Combined with the setting of the flow meter 61 and the flow regulating valve 62, the amount of washing water in the sludge washing tank 5 can be accurately controlled. This avoids adding too much washing water to the system and effectively controls the solids content of the salt mud in the sludge washing tank 5, which facilitates the improvement of the salt mud dissolution effect. After the salt mud in the sludge washing tank 5 is washed, dissolved, and diluted, the salt content is less than 1%, which meets the requirements for cement production and can be used to produce qualified cement.
[0054] Second, by setting up a secondary filter press 7, the salt mud with a salt content of less than 1% in the sludge washing tank 5 is filtered again to achieve solid-liquid separation, and dilute brine and filter cake are obtained, which can be used separately.
[0055] Third, the brine stored in the brine tank 8 is sent back to the mud washing tank 5 as washing water through the washing water supply pipe 6, thus realizing the utilization of the brine stored in the brine tank 8.
[0056] Fourth, by setting up the concentrated brine tank 3, it is convenient to collect the supernatant of the settling tank 2 and the filtrate of the first-stage filter press 4; by pumping the concentrated brine in the concentrated brine tank 3 back to the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process and mixing it with the crude brine, it is convenient to reprocess the concentrated brine with high salt content (supernatant of the settling tank 2 and filtrate of the first-stage filter press 4).
[0057] 5. The washing water temperature should be 40~60℃, which can increase the dissolution rate of salt in the salt mud.
[0058] VI. The dissolution rate of salt in the salt mud is further improved by setting up the stirring device 51.
[0059] Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Without conflict, the embodiments and features described in the embodiments of this application can be arbitrarily combined with each other. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A salt mud washing and desalination system, characterized in that, include: The settling tank has a salt mud solution inlet at the top and a salt mud outlet at the bottom. A primary filter press, the feed inlet of which is connected to the outlet of the salt mud; The sludge washing tank has its inlet connected to the solid phase outlet of the primary filter press. A washing water supply pipe is used to supply washing water to the sludge washing tank; the washing water supply pipe is equipped with an associated flow meter and flow regulating valve.
2. The salt mud washing and desalination system according to claim 1, characterized in that, The settling tank has a supernatant outlet at the top, and the supernatant outlet is connected to a concentrated brine tank.
3. The salt mud washing and desalination system according to claim 2, characterized in that, The outlet of the concentrated brine tank is connected to the front end of the primary brine refining section of the ion-exchange membrane caustic soda electrolysis process.
4. The salt mud washing and desalination system according to claim 2, characterized in that, The liquid phase outlet of the primary filter press is connected to the inlet of the concentrated brine tank.
5. The salt mud washing and desalination system according to claim 1, characterized in that, The settling trough is an inclined plate type settling trough.
6. The salt mud washing and desalination system according to claim 1, characterized in that, The mud washing tank is equipped with a stirring device.
7. The salt mud washing and desalination system according to claim 1, characterized in that, The temperature of the washing water is 40~60℃.
8. The salt mud washing and desalination system according to any one of claims 1 to 7, characterized in that, The outlet of the sludge washing tank is connected to a two-stage filter press.
9. The salt mud washing and desalination system according to claim 8, characterized in that, The liquid phase outlet of the secondary filter press is connected to a brine tank.
10. The salt mud washing and desalination system according to claim 9, characterized in that, The outlet of the saline solution tank is connected to the washing water supply pipe.