Industrial dechlorination system and method for preparing alpha gypsum by hydrothermal method

Abstract

The invention belongs to the field of chlorine removal processes, and particularly discloses an industrial dechlorination system and method for preparing alpha gypsum through a hydrothermal method. The system comprises a gypsum production assembly, a wastewater dechlorination assembly, a sedimentation tank and a water quality parameter monitoring control assembly. The gypsum production assembly is composed of a raw material tank, a dosing tank, a blending unit, a reaction unit and a separation unit, and finish machining of products is achieved. The wastewater dechlorination assembly is composed of a heat exchanger, a dechlorination pool, a dosing device, a first Cl <-> monitor and a pH monitor, and water quality adjustment and dechlorination of chlorine-containing waste liquid are achieved. And the water quality parameter monitoring control assembly consists of a Cl <-> monitor and a Ca < 2 + > monitor, and is used for controlling the dosing amount of the raw material tank and the dosing tank. The industrial dechlorination system for preparing alpha gypsum by the hydrothermal method realizes dechlorination treatment of desulfurization gypsum, can be used for industrial production, and overcomes the problems of high desulfurization gypsum chlorine removal cost and incomplete chlorine removal in industrial application in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of chlorine removal technology, and specifically relates to an industrial dechlorination system and method for preparing alpha gypsum by a hydrothermal method. Background Art

[0002] With the encouragement and support of the state for the comprehensive utilization of industrial byproduct gypsum, the resource utilization of desulfurized gypsum has become an important way to reduce pollution and protect the environment. Desulfurized gypsum is a byproduct produced during the flue gas desulfurization process of coal-fired power plants. The control of its chloride ion content is of great significance for reducing environmental pollution. By reducing the chloride ion content, the utilization value of desulfurized gypsum can be increased, and its application in green building materials and gypsum whisker new products and materials can be promoted.

[0003] The chloride ions in desulfurized gypsum mainly come from the chlorine in the coal and the chloride ions in the process water. Due to the repeated recycling of industrial water and process water in the desulfurization system, chloride ions are gradually enriched in the slurry of the absorption tower, resulting in a continuous increase in the chloride ion concentration, and even seriously exceeding the standard. Excessive chloride ion content can cause gypsum products to become damp, droopy, and yellow, and can also cause strong corrosion, seriously affecting the normal operation of the desulfurization system. Reducing the chloride ion content in gypsum can improve the dehydration effect of gypsum and promote the stability of gypsum quality. Therefore, reducing the chloride ion content in desulfurized gypsum is crucial to protecting the environment and improving the utilization rate of gypsum.

[0004] The existing technology generally cannot solve the technical problem of excessive chlorine content in desulfurized gypsum. The traditional method is to modify the existing desulfurization equipment, such as the vacuum belt dehydrator remodeling and desulfurization water source modification, but these modifications will increase the operating costs of the enterprise, and the chlorine removal is not thorough, which is not conducive to large-scale dechlorination of desulfurized gypsum. The further improved atmospheric pressure salt solution method, atmospheric pressure alcohol water method and microwave dehydration method are still in the laboratory stage and need further optimization before they can be realized in industrial production. Summary of the invention

[0005] In view of the steps existing in the above-mentioned prior art, the present invention provides an industrial dechlorination system and method for preparing alpha gypsum by a hydrothermal method. The industrial dechlorination system for preparing alpha gypsum by a hydrothermal method of the present invention comprises a gypsum production component, a wastewater dechlorination component, a sedimentation tank and a water quality parameter monitoring and control component. The dechlorination treatment of desulfurized gypsum is realized by adopting the wastewater dechlorination component, the sedimentation tank and the water quality parameter monitoring and control component, and industrial production can be carried out, thereby overcoming the problems of high cost and incomplete dechlorination of desulfurized gypsum in industrial applications of the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An industrial dechlorination system for preparing alpha gypsum by a hydrothermal method, comprising:

[0008] The gypsum production components, the dosing tank, the raw material tank, the mixing unit, the reaction unit and the separation unit are mixed in the mixing unit, and the mixing unit is provided with an agitator to promote mixing. The reaction is carried out in the reaction unit. The reaction unit adopts a high-pressure inner and outer jacketed reactor with application number CN202420246778.X. Solid-liquid separation is carried out in the separation unit. The separation unit is provided with a filter for solid-liquid separation. The mixing unit, the reaction unit and the separation unit are connected in sequence, and the raw material tank and the dosing tank are connected to the mixing unit.

[0009] The wastewater dechlorination component includes a heat exchanger, a first Cl - Monitor, dechlorination tank, dosing device and pH monitor. There is a stirrer in the dechlorination tank. The raw material tank, separation unit and dosing device are connected to the dechlorination tank. The heat exchanger is arranged between the separation unit and the dechlorination tank. The first Cl - The monitor is arranged between the heat exchanger and the dechlorination tank, and the pH monitor is installed at the outlet of the dechlorination tank; the heat exchanger can utilize the waste heat of the high-temperature chlorinated wastewater discharged from the separation unit and obtain low-temperature wastewater, which enters the dechlorination tank, and the outlet of the heat exchanger is connected to the dechlorination tank; a first Cl is also arranged on the connection passage between the heat exchanger and the dechlorination tank. - Monitor, monitor Cl in low temperature wastewater - The pH monitor is connected to the dechlorination tank, the dosage of the dosing device is adjusted according to the detection result of the pH monitor, and the outlet of the dosing device is connected to the dechlorination tank.

[0010] First Cl - A first valve is also provided on the bypass between the monitor and the dechlorination tank, and the first chloride ion monitor is electrically connected to the first valve; if the monitoring result of the first chloride ion monitor is higher than the upper limit of chloride ion concentration, the wastewater is directly discharged from the first valve without passing through the dechlorination tank for dechlorination. If the monitoring result of the first chloride ion monitor is lower than the upper limit of chloride ion concentration, the wastewater enters the dechlorination tank for dechlorination.

[0011] The sedimentation tank is connected to the dechlorination tank, and the wastewater discharged from the dechlorination tank is transported to the sedimentation tank for sedimentation treatment.

[0012] A water quality parameter monitoring and control component, comprising a second Cl - Monitor and Ca 2+ Monitor, Second Cl - Monitor and Ca 2 + The monitor is connected to the outlet of the sedimentation tank, and the sedimentation tank is connected to the inlet of the preparation unit. The aluminum salt in the dosing tank and the calcium salt in the raw material tank can remain in the supernatant after precipitation in the sedimentation tank, and the remainder enters the preparation unit after monitoring.

[0013] A feeder is provided between the raw material tank and the dechlorination tank. The outlet of the raw material tank is connected to the inlet of the feeder, and the outlet of the feeder is connected to the dechlorination tank. 2+ The monitor is electrically connected to the feeder, Ca 2+ Monitors for Ca 2+ After the concentration is determined, the flow rate of the feeder is adjusted, and then the amount of by-product gypsum added to the dechlorination tank through the raw material tank is adjusted. The outlet end of the dosing tank, the mixing unit, and the dechlorination tank are connected together through a distributor, and the second chloride ion monitor is electrically connected to the distributor. - Monitor obtains Cl - After determining the concentration, adjust the distribution amount of the distributor, and then adjust the amount of aluminum sulfate added to the dechlorination tank through the dosing tank.

[0014] Furthermore, a crystal controlling agent is stored in the dosing tank, which controls the crystal transformation and obtains α gypsum. The raw material tank stores by-product gypsum, which is desulfurized gypsum. The main component of desulfurized gypsum is calcium sulfate. The crystal controlling agent and the by-product gypsum react in the reaction unit.

[0015] Furthermore, the dosing device stores alkaline substances or sulfuric acid for adjusting pH, and the alkaline substances or sulfuric acid are discharged into the dechlorination tank to adjust the pH of the cooling wastewater to alkaline.

[0016] Furthermore, a discharger is installed on the sedimentation tank, and the precipitated calcium chloroaluminate is discharged through the discharger.

[0017] Furthermore, a ball valve is provided between the sedimentation tank and the inlet of the gypsum hydrothermal conversion unit, and the outlet of the sedimentation tank is connected to the inlet of the blending unit through the ball valve to achieve the reuse of the supernatant.

[0018] Furthermore, when the sedimentation tank is connected to the inlet end of the blending unit, heat is first exchanged in the heat exchanger to utilize the waste heat to heat the supernatant transported in the sedimentation tank.

[0019] Furthermore, a second valve and a material pump are provided between the pH monitor and the sedimentation tank. The outlet of the dechlorination tank is connected to the sedimentation tank through the valve and the material pump. The outlet of the sedimentation tank is connected to the discharge device. The other outlet of the sedimentation tank is connected to the second Cl - Monitor and Ca 2+ Monitor.

[0020] Furthermore, the separation unit is also connected to a post-processing unit, and the post-processing unit collects α-gypsum.

[0021] The present invention also protects the above-mentioned method for preparing alpha gypsum by the hydrothermal method, which comprises the following steps:

[0022] Before starting the system: all valves and dosing devices are in closed state.

[0023] When the system is in operation, the by-product gypsum in the raw material tank and the crystal controlling agent in the dosing tank are added to the preparation unit for mixing, and then transported to the reaction unit for reaction to obtain α gypsum and chlorine-containing wastewater. The separation unit is then used for solid-liquid separation, and the α gypsum is transported to the post-processing unit.

[0024] After the high-temperature chlorine-containing wastewater enters the heat exchanger for heat exchange, low-temperature wastewater is obtained. The low-temperature wastewater enters the dechlorination tank, and the by-product gypsum is added to the dechlorination tank through the raw material tank, and aluminum sulfate is added to the dechlorination tank through the dosing tank to carry out dechlorination reaction and obtain dechlorinated wastewater.

[0025] At the same time, the alkaline substance or sulfuric acid in the dosing device is discharged into the dechlorination tank for pH adjustment, and the amount of the alkaline substance or sulfuric acid is monitored by a pH monitor.

[0026] The dechlorinated wastewater is transported to the sedimentation tank for sedimentation, and the supernatant is discharged into the blending unit and 2+ The monitor adjusts the delivery amount of the feeder based on the calcium ion detection results in the supernatant, and then regulates the amount of by-product gypsum added to the dechlorination tank through the raw material tank. - The monitor adjusts the distribution amount of the distributor based on the chloride ion monitoring results in the supernatant, and then regulates the amount of aluminum sulfate added to the dechlorination tank through the dosing tank.

[0027] System shutdown: close the raw material tank, dosing tank, mixing unit, reaction unit, separation unit and heat exchanger, and stop the wastewater supply; close the dosing device, distributor, first valve, feeder and material pump; close the second valve, ball valve and discharger, and stop the discharge of sludge and supernatant.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The industrial dechlorination system for preparing α-gypsum by the hydrothermal method of the present invention includes a gypsum production component, a wastewater dechlorination component, a sedimentation tank and a water quality parameter monitoring and control component. Desulfurized gypsum is used as the raw material, and the gypsum production component is used to prepare α-gypsum, and chlorinated wastewater is obtained at the same time. At this time, not only the desulfurized gypsum is dechlorinated, but also α-gypsum that can be reused is obtained. In the wastewater dechlorination component, the chlorinated wastewater is treated with desulfurized gypsum, and the pH is adjusted to obtain dechlorinated wastewater. After the dechlorinated wastewater is precipitated in the sedimentation tank, the supernatant is discharged into the water quality parameter monitoring and control component, and the supernatant is discharged into the water quality parameter monitoring and control component through the Ca 2+ The monitor controls the delivery volume of the feeder, and then controls the amount of desulfurized gypsum added to the chlorinated wastewater, completely removing chlorine while avoiding the problem of excessive desulfurized gypsum loss; the second Cl -The monitor controls the distribution amount of the distributor, and then controls the supplement amount of aluminum sulfate in the chlorine-containing wastewater; the precipitate is discharged through the discharger. The industrial dechlorination system for preparing α-gypsum by the hydrothermal method of the present invention realizes the dechlorination of desulfurized gypsum and realizes industrial production. The dechlorination process uses desulfurized gypsum as raw material, effectively reduces the cost, and the dechlorination is thorough.

[0030] 2. If Ca 2+ If the monitoring result of the monitor does not reach the set value of calcium ion concentration, increase the delivery volume of the feeder and add calcium sulfate. 2+ If the monitoring result of the monitor reaches or exceeds the set value of calcium ion concentration, the delivery of the feeder is stopped.

[0031] 3. If the second Cl - If the chloride ion concentration of the monitor is too high, increase the amount of aluminum sulfate delivered to the dechlorination tank by the distributor and reduce the amount delivered to the deployment unit; if the second Cl - When the chloride ion concentration of the monitor has reached the requirement, the distributor stops delivering aluminum sulfate to the dechlorination tank, and the remaining aluminum sulfate enters the blending unit.

[0032] 4. The sediment in the sedimentation tank of the present invention is discharged through a discharger, and the supernatant contains calcium salt and aluminum salt. The calcium salt and aluminum salt are returned to the gypsum production component again, and the supernatant enters the blending unit through a ball valve, thereby realizing the reuse of the supernatant after wastewater dechlorination and reducing the supply of clean water.

[0033] 5. The dosing device in the wastewater dechlorination component stores alkaline substances or sulfuric acid for adjusting the pH. The pH in the dechlorination tank can be monitored by a pH monitor to adjust the amount of dosing added to the dechlorination tank by the dosing device so that the pH of the wastewater reaches the qualified 7.0-8.0.

[0034] 6. A heat exchanger is set between the separation unit and the dechlorination tank. The temperature of the high-temperature wastewater decreases after entering the heat exchanger, and the low-temperature wastewater enters the dechlorination tank for dechlorination. The excess heat in the high-temperature wastewater can heat the supernatant transported from the sedimentation tank through the heat exchanger, reducing energy loss.

[0035] 7. The industrial dechlorination system for preparing α-gypsum by hydrothermal method of the present invention comprises a gypsum production component, a wastewater dechlorination component, a sedimentation tank and a water quality parameter monitoring and control component. 2+ Monitor, First Cl - Monitor, Second Cl - Monitors and pH monitors enable precise control of feed volume, ensuring complete chlorine removal while avoiding material waste. Heat exchangers reduce the temperature of high-temperature wastewater while effectively utilizing excess heat, reducing operating costs. In addition, the supernatant in the sedimentation tank enters the gypsum production component, enabling the reuse of the supernatant and reducing the supply of clean water. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of an industrial dechlorination system for preparing alpha gypsum by a hydrothermal method according to the present invention.

[0037] Among them: 1-raw material tank; 2-dosing tank; 3-dosing device; 4-dispensing unit; 5-reaction unit; 6-separation unit; 7-heat exchanger; 8-dechlorination tank; 9-precipitation tank; 10-post-processing unit; 11-distributor; 12-feeder; 13-first Cl - Monitor; 14-first valve; 15-pH monitor; 16-second valve; 17-material pump; 18-discharge device; 19-second Cl - Monitor; 20-Ca 2+ Monitor; 21-ball valve. DETAILED DESCRIPTION

[0038] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified.

[0039] Taking into account the technical defects of the high chloride content of the prior art desulfurized gypsum, the present invention provides an industrial dechlorination system for preparing α-gypsum by a hydrothermal method, so as to achieve the dechlorination of the desulfurized gypsum and obtain α-gypsum that can be reused. The present invention proposes a subcritical hydrothermal conversion method, which allows the calcium sulfate dihydrate in the desulfurized gypsum to undergo a dissolution and recrystallization reaction in an aqueous solution. This process continuously generates α-type calcium sulfate hemihydrate, and at the same time, during the dissolution process, the chloride ions and other impurities originally wrapped in the calcium sulfate dihydrate are released, thereby achieving the effect of green dechlorination and quality improvement. In addition, after the chloride ions in the chlorine-containing wastewater are dechlorinated by using desulfurized gypsum, the calcium salts in the supernatant are beneficial to gypsum production and are reused in the water for gypsum production, reducing resource loss and industrial operating costs, which is of great significance for reducing production investment.

[0040] The industrial dechlorination system for preparing α-gypsum by the hydrothermal method and the process of the industrial dechlorination system for preparing α-gypsum by the hydrothermal method of the present invention are described in detail as follows:

[0041] Industrial dechlorination system for preparing alpha gypsum by hydrothermal method, see Figure 1 ,include:

[0042] The gypsum production component includes a raw material tank 1, a dosing tank 2, a preparation unit 4, a reaction unit 5 and a separation unit 6. The preparation unit 4, the reaction unit 5 and the separation unit 6 are connected in sequence. The raw material tank 1 and the dosing tank 2 are connected to the preparation unit 4. The dosing tank 2 stores a crystal control agent, the raw material tank 1 stores by-product gypsum, the dosing device 3 stores alkaline substances or sulfuric acid for adjusting pH, and the separation unit 6 is also connected to a post-processing unit 10.

[0043] The wastewater dechlorination component includes a heat exchanger 7, a first Cl - Monitor 13, dechlorination tank 8, dosing device 3 and pH monitor 15, raw material tank 1, separation unit 6 and dosing device 3 are connected to dechlorination tank 8, heat exchanger 7 is arranged between separation unit 6 and dechlorination tank 8, first Cl - The monitor 13 is disposed between the heat exchanger 7 and the dechlorination tank 8 , and the pH monitor 15 is installed at the outlet end of the dechlorination tank 8 .

[0044] First Cl - A first valve 14 is also provided on the bypass between the monitor 13 and the dechlorination tank 8 , and the first chloride ion monitor 13 is electrically connected to the first valve 14 .

[0045] The sedimentation tank 9 is connected to the dechlorination tank 8 . A second valve 16 and a material pump 17 are provided between the dechlorination tank 8 and the sedimentation tank 9 . A discharger 18 is also installed on the sedimentation tank 9 .

[0046] A water quality parameter monitoring and control component, comprising a second Cl - Monitor 19 and Ca 2+ Monitor 20, second Cl - Monitor 19 and Ca 2+ The monitoring instrument 20 is connected to the outlet end of the sedimentation tank 9, and the sedimentation tank 9 is connected to the inlet end of the preparation unit 4. A ball valve 21 is arranged between the sedimentation tank 9 and the inlet end of the preparation unit 4. When the sedimentation tank 9 is connected to the inlet end of the preparation unit 4, heat is exchanged in the heat exchanger 7 first, that is, pipelines are installed between the sedimentation tank 9 and the heat exchanger 7 and between the heat exchanger 7 and the preparation unit 4.

[0047] A feeder 12 is provided between the raw material tank 1 and the dechlorination tank 8. 2+ The monitor 20 is also electrically connected to the feeder 12. The outlet of the dosing tank 2, the blending unit 4, and the dechlorination tank 8 are connected together through the distributor 11, and the second chloride ion monitor 19 is electrically connected to the distributor 11.

[0048] Example 1

[0049] The method of the industrial dechlorination system for preparing alpha gypsum based on the hydrothermal method of the present invention, see Figure 1 , including the following steps:

[0050] At the initial start-up of the industrial dechlorination system for preparing α-gypsum by the hydrothermal method, ensure that the first valve 14, the discharge device 18, the ball valve 21, the distributor 11, the second valve 16, the feeder 12 and the material pump 17 are all in a closed state, and the dosing device 3, the preparation unit 4, the reaction unit 5, the separation unit 6 and the heat exchanger 7 are also in a closed state.

[0051] When the industrial dechlorination system for preparing α-gypsum based on the hydrothermal method is started, the by-product gypsum in the raw material tank 1 and the crystal controlling agent in the dosing tank 2 are first introduced into the preparation unit 4 for mixing, then introduced into the reaction unit 5 for sufficient reaction, and then introduced into the separation unit 6 for separation to obtain α-gypsum and chlorine-containing wastewater, and the α-gypsum is transported to the post-treatment unit 10.

[0052] The high-temperature chlorine-containing wastewater enters the heat exchanger 7 for heat exchange and obtains low-temperature wastewater. The excess heat after heat exchange is used to heat the supernatant refluxed from the sedimentation tank 9. The low-temperature wastewater enters the dechlorination tank 8. The pH monitor 15 monitors the pH of the low-temperature wastewater and adjusts the amount of alkaline substance or sulfuric acid added by the dosing device 3 so that the pH of the low-temperature wastewater reaches 7.0-8.0.

[0053] The by-product gypsum is mainly composed of calcium sulfate. The by-product gypsum enters the dechlorination tank 8 and is stirred by a stirrer to fully react, thereby effectively and completely removing chlorine to obtain dechlorinated wastewater.

[0054] Open the second valve 16 and the material pump 17 to transport the dechlorinated wastewater to the sedimentation tank 9 for sedimentation to obtain supernatant and sediment, open the discharger 18 to discharge the sludge, and transport the supernatant to the blending unit 4 through the ball valve 21. 2+ Monitor 20 pairs of Ca in the supernatant 2+ The monitoring result adjusts the dosage of the feeder 12 to the dechlorination tank 8. - Monitor 19 for Cl in supernatant - The monitoring results are used to adjust the amount of chemicals added by the distributor 11 to the dechlorination pool 8.

[0055] The adjustment measures during the normal operation of the industrial dechlorination system for preparing α-gypsum by hydrothermal method are as follows: a. If the first Cl - If the monitoring result of the monitor 13 is higher than the upper limit of chloride ion concentration, the wastewater is discharged directly from the first valve 14 without passing through the dechlorination tank for dechlorination; -If the monitoring result of the monitor 13 is lower than the upper limit of the chloride ion concentration, the wastewater enters the dechlorination tank 8 for dechlorination. b. If the pH value of the low-temperature wastewater is too high, increase the amount of sulfuric acid added in the dosing device 3; if the pH value in the wastewater is too low, increase the amount of sodium hydroxide added in the dosing device 3. c. If the calcium ion concentration of the supernatant in the sedimentation tank 9 is too low, increase the amount of the feeder 12; if the calcium ion concentration of the supernatant in the sedimentation tank 9 has reached or exceeded the set value, close the feeder 12. d. If the chloride ion concentration of the supernatant in the sedimentation tank 9 is too high, increase the amount of aluminum sulfate delivered to the dechlorination tank 8 by the distributor 11, and reduce the amount delivered to the preparation unit 4; if the chloride ion concentration of the supernatant in the sedimentation tank 9 has reached the requirement, stop the distributor 11 from delivering aluminum sulfate to the dechlorination tank 8, and the remaining aluminum sulfate enters the preparation unit 4.

[0056] After receiving the shutdown command, the industrial dechlorination system for preparing α-gypsum based on the hydrothermal method will sequentially close the raw material tank 1, the dosing tank 2, the preparation unit 4 and the heat exchanger 7, stop the wastewater supply, close the feeder 12, stop adding desulfurized gypsum, close the distributor 11, stop adding the crystal control agent, and the dosing device 3 will be automatically closed under the control of the pH monitor 15 after adding alkaline substances or sulfuric acid. The calcium salt and aluminum salt in the dechlorination tank 8 will enter the sedimentation tank 9 after being fully stirred and reacted with the wastewater. After the dechlorination tank 8 is completely emptied, the material pump 17 and the second valve 16 will be closed. After all the supernatant in the sedimentation tank 9 enters the preparation unit 4, the ball valve 21 will be closed, and the discharger 18 will be opened to discharge the sludge. After all the sludge is discharged, the discharger 18 will be closed.

[0057] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An industrial dechlorination system for preparing alpha gypsum by hydrothermal method, characterized in that: include: A gypsum production assembly comprises a raw material tank (1), a dosing tank (2), a mixing unit (4), a reaction unit (5) and a separation unit (6), wherein the mixing unit (4), the reaction unit (5) and the separation unit (6) are sequentially connected in series, and the raw material tank (1) and the dosing tank (2) are connected in series in series with the mixing unit (4); The wastewater dechlorination component comprises a heat exchanger (7), a first Cl - The raw material tank (1), the separation unit (6) and the dosing device (3) are connected to the dechlorination tank (8); the heat exchanger (7) is arranged between the separation unit (6) and the dechlorination tank (8); the first Cl - The monitor (13) is arranged between the heat exchanger (7) and the dechlorination tank (8), and the pH monitor (15) is installed at the outlet of the dechlorination tank (8); The first Cl - A first valve (14) is also provided on the bypass between the monitor (13) and the dechlorination tank (8), and the first chloride ion monitor (13) is electrically connected to the first valve (14); A sedimentation tank (9) which is in continuous communication with the dechlorination tank (8); A water quality parameter monitoring and control component, comprising a second Cl - Monitor (19) and Ca 2+ Monitor (20), the second Cl - Monitor (19) and the Ca 2+ The monitoring instrument (20) is connected to the outlet of the sedimentation tank (9), and the sedimentation tank (9) is connected to the inlet of the preparation unit (4); A feeder (12) is provided between the raw material tank (1) and the dechlorination tank (8). 2+ The monitor (20) is electrically connected to the feeder (12); the outlet end of the dosing tank (2), the mixing unit (4), and the dechlorination tank (8) are connected together through a distributor (11); and the second chloride ion monitor (19) is electrically connected to the distributor (11).

2. The industrial dechlorination system for preparing alpha gypsum by hydrothermal method according to claim 1, characterized in that: The raw material tank (1) stores by-product gypsum; the dosing tank (2) stores a crystal controlling agent, which is aluminum sulfate.

3. The industrial dechlorination system for preparing alpha gypsum by hydrothermal method according to claim 2, characterized in that: The dosing device (3) stores alkaline substances or sulfuric acid for adjusting pH.

4. The industrial dechlorination system for preparing alpha gypsum by hydrothermal method according to claim 3, characterized in that: A discharge device (18) is installed on the sedimentation tank (9).

5. The industrial dechlorination system for preparing alpha gypsum by hydrothermal method according to claim 4, characterized in that: A ball valve (21) is provided between the sedimentation tank (9) and the inlet end of the blending unit (4).

6. The industrial dechlorination system for preparing alpha gypsum by hydrothermal method according to claim 5, characterized in that: When the sedimentation tank (9) is connected to the inlet end of the blending unit (4), heat is exchanged in the heat exchanger (7) before it is exchanged in the heat exchanger (7).

7. The industrial dechlorination system for preparing high-strength alpha gypsum by hydrothermal method according to claim 6, characterized in that: A second valve (16) and a material pump (17) are provided between the pH monitor (15) and the sedimentation tank (9).

8. The industrial dechlorination system for preparing high-strength alpha gypsum by hydrothermal method according to claim 7, characterized in that: The separation unit (6) is also connected to a post-processing unit (10).

9. A method for an industrial dechlorination system for preparing alpha gypsum by the hydrothermal method according to claim 8, characterized in that: The following steps are involved: The by-product gypsum in the raw material tank (1) and the crystal controlling agent in the dosing tank (2) are added to the preparation unit (4) for mixing, and then transported to the reaction unit (5) for reaction to obtain α gypsum and chlorine-containing wastewater, and then the separation unit (6) is used for solid-liquid separation, and the α gypsum is transported to the post-processing unit (10); After the high-temperature chlorine-containing wastewater enters the heat exchanger (7) for heat exchange, low-temperature wastewater is obtained, and the low-temperature wastewater enters the dechlorination tank (8), and by-product gypsum is added to the dechlorination tank (8) through the raw material tank (1), and aluminum sulfate is added to the dechlorination tank (8) through the dosing tank (2), and a dechlorination reaction is performed to obtain dechlorinated wastewater; At the same time, the alkaline substance or sulfuric acid in the dosing device (3) is discharged into the dechlorination tank (8) for pH adjustment, and the amount of the alkaline substance or sulfuric acid is monitored by the pH monitor (15); The dechlorinated wastewater is transported to the sedimentation tank (9) for sedimentation, and the supernatant is discharged into the preparation unit (4), and the Ca 2+ The monitor (20) adjusts the feed rate of the feeder (12) according to the detection result of calcium ions in the supernatant, and then regulates the amount of by-product gypsum added to the dechlorination tank (8) via the raw material tank (1); and adjusts the distribution rate of the distributor (11) according to the monitoring result of chloride ions in the supernatant by the second chloride ion monitor (19), and then regulates the amount of aluminum sulfate added to the dechlorination tank (8) via the dosing tank (2).

10. The method according to claim 9, characterized in that When the pH monitor (15) detects that the pH of the dechlorination wastewater is 7.0-8.0, the chlorine-containing wastewater is discharged into the sedimentation tank (9) via the dechlorination tank (8).

Images