Device and method for applying brine refining byproduct salty mud to flue gas desulfurization process of power plant
By mixing salt mud slurry in a pre-mixed tank and using a stirring device, and utilizing the calcium carbonate component in the salt mud as a desulfurizing agent, the problems of high limestone consumption and difficult salt mud disposal in power plant flue gas desulfurization are solved, achieving efficient utilization of salt mud and environmentally friendly desulfurization effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-27
AI Technical Summary
In power plant flue gas desulfurization, limestone consumption is large, operating costs are high, and a large amount of desulfurization gypsum is generated that needs further treatment. Salt mud has a large output, complex composition, and is difficult to dispose of. Direct use of it in wet desulfurization systems poses stability problems.
The salt mud slurry is mixed using a pre-mixing tank and a stirring device. The mixing is accelerated by a circulating pump and a guide pipe to ensure uniform slurry density. The calcium carbonate component in the salt mud is used as a desulfurizing agent, which is then desulfurized by countercurrent contact with the flue gas in the absorption tower. The slurry is then further processed to form gypsum.
It has enabled the efficient utilization of salt mud, reduced the pressure of solid waste storage and disposal, replaced traditional limestone raw materials, reduced operating costs, and improved desulfurization efficiency and environmental benefits.
Smart Images
Figure CN121731950A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of salt mud treatment technology, and more specifically, to an apparatus and method for using salt mud, a byproduct of brine refining, in the flue gas desulfurization process of power plants. Background Technology
[0002] Currently, various desulfurization processes are used in power plant flue gas desulfurization. Based on their location within the production process, they can be categorized as: pre-combustion desulfurization, in-combustion desulfurization (in-furnace desulfurization), and post-combustion desulfurization, i.e., flue gas desulfurization. Among these processes, some are relatively mature and have reached industrial application levels, while others are still in the experimental research stage. Currently, the mainstream flue gas desulfurization processes include wet, dry, and semi-dry methods. Among these, limestone-gypsum wet desulfurization technology is the most widely used, offering high desulfurization efficiency and mature technology. However, it suffers from problems such as high raw material (limestone) consumption, high operating costs, and the generation of large amounts of desulfurization gypsum requiring further disposal.
[0003] Meanwhile, in the chlor-alkali chemical industry, the production of caustic soda and other products using brine refining processes generates a large amount of solid waste—salt mud. Salt mud is mainly formed by the reaction of calcium, magnesium, and other impurity ions in the brine with added sodium carbonate and sodium hydroxide, and its main components are calcium carbonate (CaCO3), magnesium hydroxide (Mg(OH)2), and silt. Statistics show that approximately 0.7 to 30 kilograms (dry basis) of salt mud are generated for every ton of caustic soda produced, with a moisture content typically between 15% and 20%. Salt mud is produced in large quantities, has a complex composition, and is difficult to dispose of. Traditional landfill or stockpiling methods not only occupy land but also pose environmental risks and disposal costs. How to achieve large-scale, high-value comprehensive utilization of salt mud has always been a technical challenge facing the industry.
[0004] Given that salt mud is rich in calcium carbonate, which can be used as a desulfurizing agent, it theoretically has the potential to replace limestone for flue gas desulfurization. However, there are many technical obstacles to directly using raw salt mud in existing wet desulfurization systems: the solid content of salt mud fluctuates greatly, and the content of impurities (such as mud, sodium salt, chloride ions, etc.) is high, which can easily lead to uneven slurry preparation and affect the stable operation of the system.
[0005] Therefore, developing a dedicated process and method for efficiently pre-treating brine to refine by-product salt mud and stably and reliably applying it to flue gas desulfurization in power plants is of great significance for achieving "waste treatment with waste", reducing desulfurization operating costs, solving the problem of salt mud disposal, and promoting the development of a circular economy. Summary of the Invention
[0006] The present invention provides an apparatus and method for using brine-refined by-product salt mud in power plant flue gas desulfurization processes, which can better mix the salt mud slurry, thereby achieving better desulfurization.
[0007] According to the present invention, an apparatus for using brine-refined by-product salt mud in a power plant flue gas desulfurization process includes a pre-preparation tank for pre-preparing salt mud slurry. The top of the pre-preparation tank is provided with a top plate, and a first rotating rod is provided at the center of the bottom surface of the top plate. Three horizontal mounting rods are circumferentially connected to the bottom end of the first rotating rod. A circular plate is connected below the rod head of the mounting rod, and a stirring device is provided below the circular plate.
[0008] An arc-shaped notch is provided on the circular plate, and a first receiving box is provided below the arc-shaped notch. The first receiving box is connected to the bottom surface of the circular plate. A second receiving box is provided below the first receiving box, and the second receiving box is connected to the precast pool through a connecting rod. The first receiving box has multiple through holes on its wall, and the second receiving box has multiple guide pipes on its wall.
[0009] The precast pool is connected to three circulation pumps, and the circulation pumps are connected to conveying pipes. The inlet of the conveying pipe is located above the first receiving box.
[0010] Preferably, the conveying pipe is equipped with a density measuring device for real-time monitoring of the density of the salt mud slurry.
[0011] Preferably, the precast pool is connected to an output pump, which is used to transport the salt mud slurry to a rotary screen to filter out large particles; the rotary screen is equipped with a slurry buffer tank, which is used to receive the screened salt mud slurry, which is used for flue gas desulfurization in power plants.
[0012] As a preferred embodiment, a first column is provided at each of the four corners of the top slab, and a second column is provided at the bottom of the precast pool.
[0013] Preferably, the first rotating rod is connected to a first motor, which is installed at the top center of the top plate.
[0014] Preferably, the rod head is provided with a mounting plate, and multiple vertical rods are provided below the mounting plate, which are connected to the circular plate.
[0015] Preferably, the stirring device includes a second rotating rod, the top of which is rotatably connected to the bottom surface of the circular plate. The second rotating rod is provided with multiple stirring blades, and the top of the second rotating rod is connected to a second motor, which is installed on the top surface of the circular plate and located in the middle of the multiple vertical rods.
[0016] Preferably, the arc-shaped notch is circular in shape, with the first rotating rod as the center.
[0017] This invention provides a method for using brine purification by-product salt mud in a power plant flue gas desulfurization process. The method employs the aforementioned apparatus for using brine purification by-product salt mud in a power plant flue gas desulfurization process and includes the following steps:
[0018] 1. The salt mud is transported to the prefabrication tank and process water is added;
[0019] 2. Activate the stirring device to mix and stir the salt mud and process water;
[0020] 3. After stirring for a period of time, turn on the circulation pump and transport the stirred salt mud slurry to the first receiving box through the conveying pipe. The salt mud slurry flows into the precast pool through the through hole.
[0021] 4. After stirring for a period of time, the first rotating rod drives the circular plate to rotate, changing the position of the stirring device. At this time, the first receiving box moves away with the circular plate, and the salt mud slurry is transported to the second receiving box. The salt mud slurry flows into a more distant position in the precast pool through the guide pipe.
[0022] 5. After stirring for a period of time, the circular plate is reset. The circular plate is rotated back and forth to stir until the salt mud slurry reaches the set density requirement.
[0023] 6. After mixing, the salt mud slurry is pumped into the absorption tower, where it comes into countercurrent contact with the flue gas through the spray layer to carry out the desulfurization reaction;
[0024] 7. The desulfurized slurry is oxidized and crystallized to form gypsum, which is then discharged after being treated by a dewatering system.
[0025] Preferably, in step six, after mixing is completed, the salt mud slurry is transported to a rolling screen by an output pump to filter out large particles, and the filtered salt mud slurry is then transported to a slurry buffer tank.
[0026] The beneficial effects of this invention are as follows:
[0027] This invention transforms the difficult-to-dispose-of by-product salt mud from the chlor-alkali industry into an effective flue gas desulfurization absorbent, achieving "waste treatment with waste," significantly reducing the pressure of solid waste storage and disposal, while replacing traditional limestone raw materials, saving natural mineral resources, and meeting the requirements of circular economy and green development.
[0028] In this invention, multiple stirring devices below the circular plate can simultaneously stir the materials in the precast tank, resulting in higher stirring efficiency. The first rotating rod can drive the stirring devices below the circular plate to rotate circumferentially, thus changing the position of the stirring devices and allowing them to stir at different locations, further improving the stirring effect. The circulating pump can transport the slurry in the precast tank to the first receiving box, and then it flows back into the precast tank through the through hole, circulating and accelerating the mixing. When the stirring devices rotate away, the first receiving box rotates away as well, and the slurry transported by the circulating pump enters the second receiving box, and then flows back into the precast tank through the guide pipe. Since the guide pipe can transport the slurry to a farther location, flowing the slurry back and forth to different places can accelerate the mixing and achieve a higher effect. Attached Figure Description
[0029] Figure 1This is a three-dimensional structural schematic diagram of an apparatus for using brine-refined by-product salt mud in a power plant flue gas desulfurization process, as described in the embodiment.
[0030] Figure 2 This is a front view schematic diagram of the internal structure of the precast pool in the embodiment;
[0031] Figure 3 This is a top view of the internal structure of the precast pool in the embodiment;
[0032] Figure 4 This is a bottom view of the internal structure of the precast pool in the embodiment. Detailed Implementation
[0033] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.
[0034] Example
[0035] like Figure 1-4 As shown, this embodiment provides an apparatus for using brine-refined by-product salt mud in power plant flue gas desulfurization processes. It includes a pre-processing tank 110 for pre-processing salt mud slurry. The top of the pre-processing tank 110 is provided with a top plate 120. A first rotating rod 130 is provided at the center of the bottom surface of the top plate 120. Three horizontal mounting rods 140 are circumferentially connected to the bottom end of the first rotating rod 130. A circular plate 150 is connected below the rod head of the mounting rod 140. A stirring device 160 is provided below the circular plate 150.
[0036] The circular plate 150 has an arc-shaped notch 151, and a first receiving box 171 is provided below the arc-shaped notch 151. The first receiving box 171 is connected to the bottom surface of the circular plate 150. A second receiving box 172 is provided below the first receiving box 171. The second receiving box 172 is connected to the precast pool 110 through a connecting rod 180. The first receiving box 171 has multiple through holes 1711 on its wall, and the second receiving box 172 has multiple guide pipes 1721 on its wall.
[0037] The precast tank 110 is connected to three circulating pumps (a filter membrane can be installed at the inlet of the circulating pump to prevent large particles of debris from entering). The circulating pumps are connected to conveying pipes, and the outlet of the conveying pipe is located above the first receiving box 171.
[0038] Multiple stirring devices 160 below the circular plate 150 can simultaneously stir the materials in the precast tank 110, resulting in higher stirring efficiency. The first rotating rod 130 can drive the stirring devices 160 below the circular plate 150 to rotate circumferentially, thus changing the position of the stirring devices 160 and allowing them to stir at different locations, further improving the stirring effect. The circulating pump can transport the slurry in the precast tank 110 to the first receiving box 171, and then it flows back into the precast tank 110 through the through hole 1711, circulating and accelerating the mixing. When the stirring devices 160 rotate away, the first receiving box 171 rotates away as well, and the slurry transported by the circulating pump enters the second receiving box 172, and then flows back into the precast tank 110 through the guide pipe 1721. Since the guide pipe 1721 can transport the slurry to a farther location, the slurry is flowed back and forth to different places, which accelerates the mixing and improves the effect.
[0039] In this embodiment, a density measuring device is installed on the conveying pipe to monitor the density of the salt mud slurry in real time.
[0040] Density measuring equipment can monitor density, and when the density reaches the required level, stirring and mixing can be stopped to proceed to the next step.
[0041] In this embodiment, the prefabrication tank 110 is connected to an output pump (a filter membrane can be installed at the inlet of the output pump to prevent large particles from entering). The output pump is used to transport the salt mud slurry to the rolling screen to filter out large particles. The rolling screen is equipped with a slurry buffer tank, which is used to receive the screened salt mud slurry. The salt mud slurry is used for flue gas desulfurization in power plants.
[0042] In this embodiment, the top plate 120 is provided with first columns 121 at each of its four corners, and the precast pool 110 is provided with second columns 111 at its bottom.
[0043] In this embodiment, the first rotating rod 130 is connected to a first motor 131, which is installed at the top center of the top plate 120. The first motor 131 can drive the first rotating rod 130 to rotate.
[0044] In this embodiment, the head of the mounting rod 140 is provided with a mounting plate 141, and a plurality of vertical rods 142 are provided below the mounting plate 141. The vertical rods 142 are connected to the circular plate 150.
[0045] In this embodiment, the stirring device 160 includes a second rotating rod 161. The top end of the second rotating rod 161 is rotatably connected to the bottom surface of the circular plate 150. The second rotating rod 161 is provided with a plurality of stirring blades 162. The top end of the second rotating rod 161 is connected to a second motor 163. The second motor 163 is installed on the top surface of the circular plate 150 and is located in the middle of the plurality of vertical rods 142.
[0046] In this embodiment, the arc-shaped notch 151 is arc-shaped and centered on the first rotating rod 130.
[0047] This embodiment provides a method for using brine purification by-product salt mud in a power plant flue gas desulfurization process. It employs the aforementioned apparatus for using brine purification by-product salt mud in a power plant flue gas desulfurization process and includes the following steps:
[0048] 1. The salt mud is transported to the prefabrication tank 110 and process water is added;
[0049] 2. Activate the stirring device 160 to mix and stir the salt mud and process water;
[0050] 3. After stirring for a period of time, turn on the circulation pump and transport the stirred salt mud slurry to the first receiving box 171 through the conveying pipe. The salt mud slurry flows into the precast pool 110 through the through hole 1711.
[0051] 4. After stirring for a period of time, the first rotating rod 130 drives the circular plate 150 to rotate, changing the position of the stirring device 160. At this time, the first receiving box 171 rotates with the circular plate 150, and the salt mud slurry is transported to the second receiving box 172. The salt mud slurry flows into the precast pool 110 at a more distant position through the guide pipe 1721.
[0052] 5. After stirring for a period of time, the circular plate 150 is reset. The circular plate 150 is rotated back and forth to stir until the salt mud slurry reaches the set density requirement.
[0053] 6. After mixing, the salt mud slurry is pumped into the absorption tower, where it comes into countercurrent contact with the flue gas through the spray layer to carry out the desulfurization reaction;
[0054] 7. The desulfurized slurry is oxidized and crystallized to form gypsum, which is then discharged after being treated by a dewatering system.
[0055] In step six, after mixing is completed, the salt mud slurry is transported to a rolling screen by an output pump to filter out large particles, and the filtered salt mud slurry is then transported to a slurry buffer tank.
[0056] Utilizing salt mud slurry for boiler flue gas desulfurization is a full utilization of resources and a manifestation of new productive forces. Salt mud is generated when industrial salt or brine is used in the chlor-alkali industry. Sodium carbonate, sodium hydroxide, and barium chloride are added to remove harmful ions such as calcium, magnesium, and sulfate. The resulting precipitate, along with mechanical impurities from the industrial salt, forms salt mud. Its main components are CaCO3, Mg(OH)2, and silt. For every ton of caustic soda produced, the yield of salt mud (dry basis) using refined salt is 0.7–6.0 kg, while the average yield (dry basis) when the salt contains more impurities is 30 kg. The water content of the salt mud is 15%–20%. Salt mud is a large waste residue generated during the brine purification process in the chlor-alkali industry, containing calcium carbonate, magnesium hydroxide, sodium chloride, and iron. Due to its large output and complex composition, direct discharge causes environmental pollution. How to comprehensively utilize this solid waste is a difficult problem for the industry.
[0057] Therefore, this embodiment uses a wet flue gas desulfurization process with waste salt sludge as the desulfurizing agent. The waste salt sludge has a solids content of 10%–25%, a total alkalinity of 36.7–91.9 g / L, a circulating slurry pH controlled at 5–6, and a liquid-to-gas ratio of 8–15 L / m³ in the absorption tower. 3 The effective components in waste salt mud react with acidic gases such as SO2 in flue gas to remove sulfur dioxide, thus achieving flue gas desulfurization. This process replaces desulfurizing agents in wet flue gas desulfurization processes, such as limestone, lime, magnesium oxide, and ammonia / ammonia water. This process treats waste with waste, making efficient use of waste materials, saving traditional desulfurization absorbent resources, reducing operating costs, and purifying flue gas, resulting in significant environmental, economic, and social benefits.
[0058] The desulfurization process is described in detail below:
[0059] Flue gas from the boiler, after passing through a bag filter, enters the absorption tower under the action of an induced draft fan. The absorption tower is a counter-current spray empty tower structure, where the flue gas after dust removal comes into counter-current contact with the circulating slurry inside the absorption tower. The system is equipped with 1 to 4 slurry circulation pumps, each corresponding to one layer of atomized spray scrubbing. The slurry after SO2 absorption enters the bottom of the absorption tower. Simultaneously, the absorbent preparation system supplies fresh CaCO3 slurry to the absorption system to replenish the consumed calcium carbonate, maintaining a certain pH value in the absorption slurry under forced oxidation. When the load changes, 1-2 spray layers can be adjusted, while the system still maintains a high liquid-to-gas ratio, thus achieving the required desulfurization and scrubbing effect. A demister is installed at the top of the absorption zone, separating droplets and dust entrained in the clean flue gas. The droplet concentration in the flue gas at the demister outlet is no greater than 20 mg / Nm³. 3 (Dry basis, actual oxygen consumption), and the dust concentration in the outlet flue gas is ≤5 mg / Nm³. 3(Dry basis, actual oxygen consumption, including gypsum). Mainly reflects:
[0060] When sulfur dioxide is insufficient, the reaction equation is: SO2 + Ca(OH)2 = CaSO3 (precipitate) + H2O
[0061] When sulfur dioxide is present in an appropriate amount, the reaction equation is: 2SO2 + Ca(OH)2 = Ca(HSO3)2
[0062] Due to the large circulation volume of the absorbent and the introduction of oxidizing air, almost all of the HSO3 or sulfite in the slurry pool at the bottom of the absorption tower is oxidized to sulfate or sulfate. Finally, after CaSO4 reaches a certain supersaturation, it crystallizes to form gypsum-CaSO4·2H2O. The gypsum can be comprehensively utilized or disposed of as needed.
[0063] The desulfurization process system for salt mud slurry mainly consists of a flue gas system, an absorption and oxidation system, a slurry preparation system, a gypsum dewatering system, and an emission system.
[0064] Desulfurization is achieved through spray scrubbing. Spray scrubbing offers a high scrubbing rate; the flue gas is evenly dispersed and repeatedly reacts with the sprayed slurry in the screen plate and spray zone, resulting in strong impact and excellent secondary atomization. The sprayed water particles are smaller, significantly increasing the contact between water droplets and flue gas, thus leading to higher desulfurization efficiency. Simultaneously, improved mass transfer efficiency and increased liquid-gas contact area reduce operating costs. Practical application has proven that the mass transfer efficiency of screen plate scrubbing technology is 5-10 percentage points higher than that of cyclone scrubbing.
[0065] The main component of salt mud is CaCO3, and its use as a desulfurizing agent relies on this CaCO3. Salt mud has a complex composition; besides containing 58.23% CaCO3, it also contains many impurities. These impurities can have adverse effects on desulfurization, so measures must be taken to minimize their impact. The main impurities that negatively affect desulfurization include sand, gravel, and sodium. + elemental S, Cl - The following countermeasures should be taken: ① For sand and gravel, use a vibrating screen in the pulping system to screen them out of the system; ② Thicken the anti-wear layer in the reaction zone of the desulfurization tower to prevent fine sand and acid-insoluble substances from wearing down the desulfurization tower; ③ Lower the operating pH value to prevent Na+ from accumulating. + Ca 2+ ④ Appropriately increase the liquid-to-gas ratio to compensate for the impact of lowering the pH value on desulfurization efficiency.
[0066] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.
Claims
1. An apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization processes, characterized in that: The prefabrication tank (110) is used for pre-preparing salt mud slurry. The top of the prefabrication tank (110) is provided with a top plate (120). A first rotating rod (130) is provided at the center of the bottom surface of the top plate (120). Three horizontal mounting rods (140) are circumferentially connected to the bottom end of the first rotating rod (130). A circular plate (150) is connected below the rod head of the mounting rod (140). A stirring device (160) is provided below the circular plate (150). An arc-shaped notch (151) is provided on the circular plate (150), and a first receiving box (171) is provided below the arc-shaped notch (151). The first receiving box (171) is connected to the bottom surface of the circular plate (150). A second receiving box (172) is provided below the first receiving box (171). The second receiving box (172) is connected to the precast pool (110) through a connecting rod (180). The first receiving box (171) has multiple through holes (1711) on its wall, and the second receiving box (172) has multiple guide pipes (1721) on its wall. The precast pool (110) is connected to three circulating pumps, which are connected to conveying pipes. The inlet of the conveying pipe is located above the first receiving box (171).
2. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 1, characterized in that: The conveying pipe is equipped with a density measuring device for real-time monitoring of the density of the salt mud slurry.
3. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 2, characterized in that: The prefabrication tank (110) is connected to an output pump, which is used to transport the salt mud slurry to the rolling screen to filter out large particles; the rolling screen is equipped with a slurry buffer tank, which is used to receive the salt mud slurry after screening, and the salt mud slurry is used for flue gas desulfurization in power plants.
4. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 3, characterized in that: The top plate (120) is provided with a first column (121) at each of the four corners, and the precast pool (110) is provided with a second column (111) at the bottom.
5. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 4, characterized in that: The first rotating rod (130) is connected to the first motor (131), which is installed at the top center of the top plate (120).
6. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 5, characterized in that: The mounting rod (140) has a mounting plate (141) at its head, and multiple vertical rods (142) are provided below the mounting plate (141). The vertical rods (142) are connected to the circular plate (150).
7. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 6, characterized in that: The stirring device (160) includes a second rotating rod (161), the top end of which is rotatably connected to the bottom surface of the circular plate (150). The second rotating rod (161) is provided with multiple stirring blades (162), and the top end of the second rotating rod (161) is connected to a second motor (163). The second motor (163) is installed on the top surface of the circular plate (150) and located in the middle of the multiple vertical rods (142).
8. The apparatus for using brine purification by-product salt mud in power plant flue gas desulfurization process according to claim 7, characterized in that: The arc-shaped notch (151) is arc-shaped and centered on the first rotating rod (130).
9. A method for using brine purification by-product salt mud in power plant flue gas desulfurization processes, characterized in that: It employs an apparatus as described in any one of claims 1-8 for using brine purification by-product salt mud in power plant flue gas desulfurization processes, and includes the following steps:
1. The salt mud is transported to the prefabrication tank (110) and process water is added; 2. Activate the stirring device (160) to mix and stir the salt mud and process water; 3. After stirring for a period of time, turn on the circulation pump and transport the stirred salt mud slurry to the first receiving box (171) through the conveying pipe. The salt mud slurry flows into the precast pool (110) through the through hole (1711).
4. After stirring for a period of time, the first rotating rod (130) drives the circular plate (150) to rotate, changing the position of the stirring device (160). At this time, the first receiving box (171) rotates away with the circular plate (150), and the salt mud slurry is transported to the second receiving box (172). The salt mud slurry flows into the precast pool (110) at a more distant position through the guide pipe (1721).
5. After stirring for a period of time, the circular plate (150) is reset. The circular plate (150) is rotated back and forth to stir until the salt mud slurry reaches the set density requirement.
6. After mixing, the salt mud slurry is pumped into the absorption tower, where it comes into countercurrent contact with the flue gas through the spray layer to carry out the desulfurization reaction; 7. The desulfurized slurry is oxidized and crystallized to form gypsum, which is then discharged after being treated by a dewatering system.
10. A method for using brine purification by-product salt mud in a power plant flue gas desulfurization process according to claim 9, characterized in that: In step six, after mixing is completed, the salt mud slurry is transported to a rolling screen by an output pump to filter out large particles, and the filtered salt mud slurry is then transported to a slurry buffer tank.