An acid mine drainage treatment system and method of use thereof

Abstract

The application discloses an acid mine drainage treatment system and a use method thereof, and belongs to the technical field of acid mine drainage treatment. The acid mine drainage treatment system comprises an iron removal device, a neutralization device and a control device, and is characterized in that the iron removal device comprises an adjusting pool, an injection pipe arranged at the side end of the adjusting pool, a reaction mechanism arranged beside the adjusting pool, a first conveying mechanism connecting the reaction mechanism and the adjusting pool, an iron precipitation pool arranged beside the reaction mechanism, and a first connecting pipe connecting the reaction mechanism and the iron precipitation pool; the neutralization device comprises a neutralization mechanism arranged beside the iron precipitation pool, a second conveying mechanism connecting the iron precipitation pool and the neutralization mechanism, a neutralization precipitation pool arranged beside the neutralization mechanism, a second connecting pipe connecting the neutralization mechanism and the neutralization precipitation pool, a third conveying mechanism arranged at one side of the neutralization precipitation pool and a siphon mechanism. The application can realize the treatment of acid mine drainage, resource recycling and mine filling.

Description

Technical Field

[0001] This invention relates to the field of acidic mine wastewater treatment technology, specifically to an acidic mine wastewater treatment system and its usage method. Background Technology

[0002] The overexploitation of metal mineral resources is causing increasingly serious damage to the mining environment; after mining, a large number of abandoned mine shafts are left behind; and abandoned mine shafts can damage and deform underground rock strata, easily triggering geological disasters such as collapses and earthquakes. Furthermore, abandoned mine shafts often accumulate large amounts of water due to prolonged exposure to the external environment. Under the action of microorganisms and water, sulfide minerals in waste ore or slag are often oxidized, producing acidic mine drainage (acidic mine wastewater). This is a typical type of wastewater with extremely low pH and high Fe and Mn content. Heavy metals are non-biodegradable and accumulate in organisms along with the ecosystem, leading to various diseases. Once they appear, they are difficult to control and pose a serious threat to the flowing ecosystem. This not only easily causes groundwater pollution, affecting the water supply and ecological environment of surrounding areas, but also causes land subsidence, posing safety hazards such as collapses and dam failures, and threatening nearby residents and buildings. In order to limit the harmful impact of pollutants on the surrounding environment, the treatment and management of abandoned mine shafts are very important. Effective treatment methods must be taken before the release of acidic mine wastewater, such as landfilling, solidification, and sealing, to reduce its harm to the environment and humans.

[0003] Due to the presence of sulfur-oxidizing bacteria and the influence of turbulence in acidic mine wastewater, Fe in acidic mine wastewater is usually in the form of Fe2+. 3+ The presence of OH groups in the solution is currently overlooked in the treatment of acidic mine wastewater. − The increase in Fe 3+ Precipitates in the form of iron hydroxyl compounds, such as ferric hydroxide, α-FeOOH, and γ-FeOOH, which hinder the reaction between acidic mine wastewater and alkaline neutralizing agents, resulting in ineffective treatment of acidic mine wastewater.

[0004] Currently, most treatments for acidic mining wastewater involve reacting with alkaline neutralizing agents. While this method can treat the acidic wastewater, there is no effective way to treat the resulting precipitates. For example, Chinese patent (CN115072902A) describes a process for efficiently removing iron and manganese ions from acidic mining wastewater by adjusting the pH with calcium hydroxide to precipitate Fe and by adjusting the pH with carbide slag to precipitate Mn. Although this method treats the acidic mining wastewater, the resulting sludge is not treated, which can have environmental impacts.

[0005] Therefore, in order to solve the above problems, this paper proposes an acidic mine wastewater treatment system and its application method. Summary of the Invention

[0006] The purpose of this invention is to propose an acidic mine wastewater treatment system that can recover resources from acidic mine wastewater, treat acidic mine wastewater, and use the treated products to fill mine goafs and roadways.

[0007] To achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution: an acidic mine wastewater treatment system, comprising an iron removal device, a neutralization device, and a control device, characterized in that: the iron removal device includes an equalization tank, an injection pipe disposed at the side of the equalization tank, a sludge discharge pipe disposed at the bottom of the equalization tank, a reaction mechanism disposed beside the equalization tank, a first conveying mechanism connecting the reaction mechanism and the equalization tank, an iron precipitation tank disposed beside the reaction mechanism, and a first connecting pipe connecting the reaction mechanism and the iron precipitation tank; the neutralization device includes a neutralization mechanism disposed beside the iron precipitation tank, a second conveying mechanism connecting the iron precipitation tank and the neutralization mechanism, a neutralization precipitation tank disposed beside the neutralization mechanism, a second connecting pipe connecting the neutralization mechanism and the neutralization precipitation tank, a third conveying mechanism and a siphon mechanism disposed on one side of the neutralization precipitation tank; the control device includes a workbench, a control panel disposed at the upper end of the workbench and a solar panel, and a battery installed inside the workbench.

[0008] Furthermore, the side walls of the equalization tank, iron sedimentation tank, and neutralization sedimentation tank are all equipped with sludge level monitors; the first conveying mechanism, the second conveying mechanism, and the third conveying mechanism each include a liquid pump fixedly installed at a certain height on the side wall of each tank and a liquid delivery pipe fixedly connected to the output end of the liquid pump; the sludge level monitors and the liquid pumps are all electrically connected to the control panel.

[0009] Furthermore, the reaction mechanism includes a reaction tower, multiple reaction nozzles equidistantly and circumferentially installed at the top of the reaction tower, a circulation pump located at the bottom of the reaction tower, a circulation pipe with a check valve fixedly connected to the output end of the circulation pump and the main pipe of the reaction nozzles, a pH sensor and a liquid level sensor located on the side wall of the reaction tower, an ammonia injection mechanism installed on the side wall of the reaction tower, and a liquid outlet with a first liquid outlet solenoid valve located at the bottom of the reaction tower; the end of the delivery pipe of the first conveying mechanism is fixedly connected to the main pipe of the reaction nozzles; the first connecting pipe is fixedly connected to the lower end of the liquid outlet; the circulation pump, pH sensor, liquid level sensor and the first liquid outlet solenoid valve are all electrically connected to the control panel.

[0010] Furthermore, the ammonia injection mechanism includes an ammonia tank installed on the side wall of the reaction tower, an air compressor and a mixing chamber, a concentration sensor installed inside the mixing chamber, a return pipe with a check valve fixedly connected to the top of the reaction tower and the side wall of the mixing chamber, and an air pipe with an aeration head fixedly connected to the mixing chamber and the interior of the reaction tower; the outlets of the ammonia tank and the air compressor are fixedly connected to the mixing chamber through a connecting pipe, and the mixing chamber is fixedly connected to the lower part of the reaction tower through an air inlet pipe; the ammonia tank, the air compressor and the concentration sensor are all electrically connected to the control panel.

[0011] Furthermore, the neutralization mechanism includes a neutralization tower located next to the iron sedimentation tank, multiple neutralization nozzles equidistantly arranged in a circular pattern at the top of the neutralization tower, a neutralization chamber located in the middle of the neutralization tower, a neutralizing agent installed inside the neutralization chamber, output holes equidistantly and evenly arranged at 0.5cm~1cm at the bottom of the neutralization chamber, and a collection chamber located at the bottom of the neutralization tower; the end of the delivery pipe of the second conveying mechanism is fixedly connected to the main pipe of the neutralization nozzles; the second connecting pipe is fixedly connected to the lower end of the collection chamber.

[0012] Furthermore, the neutralizing agent is one or more of calcite, dolomite, calcium hydroxide, and flocculant, wherein the calcite particle size is 2-3 cm, the dolomite particle size is 1-2 cm, and the calcium hydroxide particle size is 1-2 cm.

[0013] Furthermore, the control panel is equipped with a control unit, an alarm, and a timer inside, and a display screen and control knobs on its outer surface.

[0014] Furthermore, all components in the aforementioned acidic mine wastewater treatment system are made of corrosion-resistant materials.

[0015] Another object of the present invention is to provide a method of using an acidic mine wastewater treatment system, characterized in that:

[0016] S1. Before using this system, the neutralizing agent needs to be placed inside the neutralization chamber. Then, select a suitable location to install the reaction mechanism and neutralization mechanism. Based on the location of the installed reaction mechanism and neutralization mechanism, select a suitable location to construct an equalization tank, an iron precipitation tank, and a neutralization precipitation tank. Install a sludge level monitor and a pump at a suitable location in the equalization tank, iron precipitation tank, and neutralization precipitation tank (the inlet of the pump should be higher than the monitoring height of the sludge level monitor). Then, connect one end of the infusion pipe to the output port of the pump, and connect the other end of the infusion pipe to the corresponding mechanism. Install the control device in a suitable location, connect the control panel, solar panel, and battery on the workbench, and then connect the components electrically connected to the control panel to the control panel through the control line to complete the installation of each mechanism before using this system.

[0017] S2. After the device is installed, the initial settings of each component electrically controlled by the control panel on the operating workbench are realized, and the preparation work before use is completed.

[0018] S3. After completing the preparation work, the staff will pump the acidic mine wastewater into the equalization tank through the injection pipe for preliminary sedimentation. Then, the first conveying mechanism's pump will evenly pump the acidic mine wastewater into the main pipe and spray it into the reaction tower through the reaction nozzles. Simultaneously, the control panel will automatically control the ammonia tank and air compressor to inject ammonia and compressed air into the mixing tank to form a mixed gas. Based on the concentration sensor feedback, the air-to-ammonia ratio in the mixing tank will be adjusted to within the range of 2-4:3-6 and input into the reaction tower to react with the acidic mine wastewater sprayed into the tower. During this process, when the level sensor detects that the liquid level inside the reaction tower has reached the set monitoring value, the control panel will automatically stop the pump of the first conveying mechanism and simultaneously control the circulation pump to operate. The acidic mine wastewater at the bottom of the reaction tower is repeatedly sprayed through a circulation mechanism and reaction nozzles, allowing the acidic mine wastewater to fully react with the mixed gas. During this process, the mixed gas that has not reacted with the acidic mine wastewater continues to circulate inside the reaction tower through the return pipe until the pH reaches 3.8~4.2. At this point, the circulation pump is turned off, and the first liquid outlet solenoid valve is opened to inject the treated acidic mine wastewater into the iron precipitation tank through the first connecting pipe. After a period of injection, the first liquid outlet solenoid valve is automatically closed under the action of the timer inside the control panel. The above steps are then repeated to continue the treatment until the iron precipitate in the iron precipitation tank reaches the monitoring height of the mud level monitor. At this point, the end of the first connecting pipe is placed into another iron precipitation tank to continue the treatment. The iron precipitation tank where the iron precipitate reaches the monitoring height of the mud level monitor then proceeds to the next step.

[0019] S4. When the height of the iron precipitate reaches the monitoring height of the mud level monitor, the pump of the second conveying mechanism is automatically started to inject the iron-removed acidic mine wastewater above the iron precipitate into the neutralization tower. The iron-removed acidic mine wastewater is then sprayed through the neutralization nozzles to fully react with the neutralizing agent inside the neutralization chamber. After the reaction, the mine wastewater is obtained. At this time, the mine wastewater flows through the 0.5cm~1cm output hole at the bottom of the neutralization chamber to the collection chamber and then through the second connecting pipe to the neutralization sedimentation tank. After a period of sedimentation, the treated supernatant and precipitate are obtained.

[0020] S5. The supernatant obtained after treatment in the neutralization sedimentation tank is transported to a suitable place through the third conveying mechanism for utilization or discharge. The sediment obtained after treatment in the neutralization sedimentation tank is transported to the goaf and roadway in the lower mine through the siphon mechanism for backfilling. The process can be carried out continuously under the control of the control panel.

[0021] The beneficial effects of this invention are:

[0022] 1) This invention uses ammonia to adjust the pH, so that Fe becomes ferric hydroxide precipitate, without producing α-FeOOH and γ-FeOOH, thus hindering the reaction between acidic mine wastewater and alkaline neutralizing agent;

[0023] 2) This invention completes the oxidation and pH adjustment processes through a reaction tower, while excess gas is reused through a circulation device, which is simple, efficient, reduces investment, and saves resources;

[0024] 3) The ferric hydroxide precipitate produced by this invention can be used as a raw material for heavy metal remediation agents, water treatment agents, mineral coatings, and other iron and manganese-related preparations;

[0025] 4) This invention automatically controls the input of ammonia and the separation of mud and water through equipment such as ammonia concentration sensors and mud level detectors, which can reduce labor costs;

[0026] 5) This invention utilizes the precipitate formed by the reaction of a neutralizing agent with acidic mine wastewater to fill the goaf and roadways of coal mines, effectively preventing and eliminating the occurrence of geological disasters;

[0027] 6) Through the cooperation of various parts, this invention achieves the purpose of resource recovery, treatment of acidic mine wastewater, and filling of mine goaf and roadway. Furthermore, the raw materials used in this invention are widely available, inexpensive, and simple to process, and are easy to operate. It can also make in-situ resource utilization of the sludge and recovered iron generated in the reaction. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the overall system structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the internal structure of the regulating tank of the present invention;

[0031] Figure 3 This is a schematic diagram of the reaction mechanism structure of the present invention;

[0032] Figure 4 This is a schematic diagram of the internal structure of the reaction tower of the present invention;

[0033] Figure 5 This is the present invention. Figure 4 Enlarged view of point A in the middle;

[0034] Figure 6 This is a schematic diagram of the internal structure of the neutralization tower in this invention;

[0035] Figure 7 This is a schematic diagram of the internal structure of the sedimentation tank in this invention;

[0036] Figure 8 This is a schematic diagram of the control device structure of the present invention;

[0037] The attached diagram lists the components represented by each number as follows:

[0038] 1. Iron removal device; 11. Equalization tank; 111. Sludge level monitor; 12. Injection pipe; 13. Sludge discharge pipe; 14. Reaction mechanism; 141. Reaction tower; 142. Reaction nozzle; 143. Circulation pump; 144. Circulation pipe with one-way valve; 145. pH sensor; 146. Liquid level sensor; 147. Ammonia injection mechanism; 147-1. Ammonia tank; 147-2. Air compressor; 147-3. Mixing box; 147-4. Concentration sensor; 147-5. Return pipe with check valve; 147-6. Pipe with aeration head; 148. Liquid outlet; 49. First liquid discharge solenoid valve; 15. First conveying mechanism; 151. Liquid pump; 152. Liquid delivery pipe; 16. Iron sedimentation tank; 17. First connecting pipe; 2. Neutralization device; 21. Neutralization mechanism; 211. Neutralization tower; 212. Neutralization nozzle; 213. Neutralization chamber; 214. Neutralizing agent; 215. Output port; 216. Collection chamber; 22. Second conveying mechanism; 23. Neutralization sedimentation tank; 24. Second connecting pipe; 25. Third conveying mechanism; 26. Siphon mechanism; 3. Control device; 31. Workbench; 32. Control panel; 33. Solar panel. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] See Figures 1 to 8 As shown, an acidic mine wastewater treatment system includes an iron removal device 1, a neutralization device 2, and a control device 3. The iron removal device 1 comprises an equalization tank 11, an injection pipe 12 located at the side of the equalization tank 11, a sludge discharge pipe 13 located at the bottom of the equalization tank 11, a reaction mechanism 14 located beside the equalization tank 11, a first conveying mechanism 15 connecting the reaction mechanism 14 and the equalization tank 11, an iron precipitation tank 16 located beside the reaction mechanism 14, and a first connecting pipe 17 connecting the reaction mechanism 14 and the iron precipitation tank 16. The neutralization device 2 includes a neutralization mechanism 21 disposed next to the iron sedimentation tank 16, a second conveying mechanism 22 connecting the iron sedimentation tank 16 and the neutralization mechanism 21, a neutralization sedimentation tank 23 disposed next to the neutralization mechanism 21, a second connecting pipe 24 connecting the neutralization mechanism 21 and the neutralization sedimentation tank 23, and a third conveying mechanism 25 and a siphon mechanism 26 disposed on one side of the sedimentation tank 23; the control device 3 includes a workbench 31, a control panel 32 disposed on the upper end of the workbench 31 and a solar panel 33, and a battery installed inside the workbench 31.

[0042] The equalization tank 11, iron sedimentation tank 16, and neutralization sedimentation tank 23 are all equipped with sludge level monitors 111 on their side walls. The first conveying mechanism 15, the second conveying mechanism 22, and the third conveying mechanism 25 each include a pump 151 fixedly installed at a certain height on the side wall of each tank, and a delivery pipe 152 fixedly connected to the output end of the pump 151. The sludge level monitors 111 and the pumps 151 are electrically connected to the control panel 32. This allows for monitoring of sedimentation in the equalization tank 11, iron sedimentation tank 16, and neutralization sedimentation tank 23, achieving automatic control of sludge-water separation.

[0043] The reaction mechanism 14 includes a reaction tower 141, multiple reaction nozzles 142 equidistantly arranged circumferentially at the top of the interior of the reaction tower 141, a circulation pump 143 located at the bottom of the interior of the reaction tower 141, a circulation pipe 144 with a one-way valve fixedly connected to the output end of the circulation pump 143 and the main pipe of the reaction nozzles 142, a pH sensor 145 and a liquid level sensor 146 located on the side wall of the interior of the reaction tower 141, an ammonia injection mechanism 147 installed on the side wall of the reaction tower 141, and a liquid outlet 148 with a first liquid outlet solenoid valve 149 located at the bottom of the reaction tower 141; the end of the delivery pipe 152 of the first delivery mechanism 15 is fixedly connected to the main pipe of the reaction nozzles 142; the first connecting pipe 17 is fixedly connected to the lower end of the liquid outlet 148; the circulation pump 142, pH sensor 145, liquid level sensor 146 and the first liquid outlet solenoid valve 149 are all electrically connected to the control panel 32. The acidic mine wastewater is repeatedly circulated and sprayed through the circulation pump 143, pH sensor 145, liquid level sensor 146 and first discharge solenoid valve 149, so that the acidic mine wastewater is fully oxidized and pH adjusted. It can only be released when the pH is adjusted to a certain range and enter the next treatment. The operation is simple and efficient, reduces investment and saves resources.

[0044] The ammonia injection mechanism 147 includes an ammonia tank 147-1, an air compressor 147-2, and a mixing chamber 147-3 installed on the side wall of the reaction tower 141. A concentration sensor 147-4 is installed inside the mixing chamber 147-3. A return pipe 147-5 with a check valve is fixedly connected to the top of the reaction tower 141 and the side wall of the mixing chamber 147-3. An aeration pipe 147-6 with an aeration head is fixedly connected to the mixing chamber 147-3 and the interior of the reaction tower 141. The outlets of the ammonia tank 147-1 and the air compressor 147-2 are fixedly connected to the mixing chamber 147-3 via connecting pipes. The mixing chamber 147-3 is fixedly connected to the lower part of the reaction tower 141 via an inlet pipe 147-4. The ammonia tank 147-1, the air compressor 147-2, and the concentration sensor 147-4 are all electrically connected to the control panel 32. The pH is adjusted by using ammonia gas, causing Fe to precipitate as ferric hydroxide, thus preventing the formation of α-FeOOH and γ-FeOOH and hindering the reaction between acidic mine wastewater and alkaline neutralizing agent. At the same time, a reflux pipe 147-5 is installed to allow the gas that has not reacted with the acidic mine wastewater to be reused through a circulation device.

[0045] The neutralization mechanism 21 includes a neutralization tower 211 located beside the iron precipitation tank 16, multiple neutralization nozzles 212 equidistantly arranged in a circular pattern at the top of the neutralization tower 211, a neutralization chamber 213 located in the middle of the neutralization tower 211, a neutralizing agent 214 installed inside the neutralization chamber 213, output holes 215 evenly spaced at 0.5cm~1cm from the bottom of the neutralization chamber 213, and a collection chamber 216 located at the bottom of the neutralization tower 211. The end of the delivery pipe 152 of the second conveying mechanism 22 is fixedly connected to the main pipe of the neutralization nozzles 142; the second connecting pipe 24 is fixedly connected to the lower end of the collection chamber 216. This mechanism achieves pH adjustment of the acidic mine wastewater after iron removal, and simultaneously causes other metal ions in the acidic mine wastewater after iron removal to react with the neutralizing agent 214 to form precipitates, reducing the concentration of metal ions and preventing the treated substances from causing harm to the environment and organisms.

[0046] The neutralizing agent 214 is composed of one or more of calcite, dolomite, calcium hydroxide, and flocculant. The calcite has a particle size of 2-3 cm, the dolomite has a particle size of 1-2 cm, and the calcium hydroxide has a particle size of 1-2 cm. Alkaline substances are used to adjust the pH and simultaneously remove other metal ions from the acidic mine wastewater.

[0047] The control panel 32 is equipped with a control unit, an alarm, and a timer inside, and a display screen and control knob on its outer surface. It can automatically control the operation of each component, and at the same time realize time control and issue an alarm in time when a certain condition exceeds the pre-set condition during actual operation.

[0048] All components in the aforementioned acidic mine wastewater treatment system are made of corrosion-resistant materials. This prevents corrosion of components caused by prolonged use of acidic mine wastewater, thus extending the service life of the components.

[0049] Example 2

[0050] Instructions for use: S1. Before using this system, neutralizing agent 214 needs to be placed inside neutralization chamber 213. Then, select a suitable location to install reaction mechanism 14 and neutralization mechanism 21. Based on the location of the installed reaction mechanism 14 and neutralization mechanism 21, select a suitable location to construct equalization tank 11, iron sedimentation tank 16, and neutralization sedimentation tank 23. Install sludge level monitor 111 and liquid pump 151 (the inlet of liquid pump 151 is higher than the monitoring height of sludge level monitor 111) at suitable locations in equalization tank 11, iron sedimentation tank 16, and neutralization sedimentation tank 23. Then, connect one end of the infusion pipe 152 to the output port of liquid pump 151, and connect the other end of the infusion pipe 152 to the corresponding mechanism. Install control device 3 in a suitable location. Connect control panel 32, solar panel 33, and battery 34 located on workbench 31. Then, connect the components electrically connected to control panel 32 to control panel 32 through control lines to complete the installation of each mechanism before using this system.

[0051] S2. After the device is installed, the monitoring height of the mud level monitor 111, the monitoring height of the liquid level sensor 146, the initial operating rate of the circulating pump 143, the liquid pump 151, the ammonia tank 147-1 and the air compressor 147-2, the range of the pH sensor 145, and the monitoring value of the pH concentration sensor 147-4 are set through the control panel 32 on the operating workbench 31. The initial settings of each component electrically controlled by the control panel 32 are completed, and the preparation work before use is completed.

[0052] S3. After the preparation work is completed, the staff will draw the acidic mine wastewater into the equalization tank 11 through the injection pipe 12 for preliminary sedimentation. Then, the acidic mine wastewater will be evenly drawn into the main pipe by the pump 151 of the first conveying mechanism 15 and sprayed into the reaction tower 141 through the reaction nozzle 142. At the same time as spraying, the control panel 32 will automatically control the ammonia tank 147-1 and the air compressor 147-2 to operate, injecting ammonia and compressed air into the mixing box 147-3 to form a mixture. The air-to-ammonia ratio in the mixing tank 147-3 is adjusted to a range of 2-4:3-6 based on feedback from the concentration sensor 147-4, and then introduced into the reaction tower 141 to react with the acidic mine wastewater sprayed into the reaction tower 141. During this process, when the liquid level sensor 146 detects that the liquid level inside the reaction tower 141 has reached the set monitoring value, the control panel 32 automatically controls the pump 151 of the first conveying mechanism 15 to stop working, and simultaneously controls... The circulation mechanism is activated, and the acidic mine wastewater at the bottom of the reaction tower 141 is repeatedly sprayed through the circulation pump 143 and the reaction nozzle 142, so that the acidic mine wastewater can fully react with the mixed gas. During this process, the mixed gas that has not reacted with the acidic mine wastewater continues to circulate inside the reaction tower 141 through the return pipe 147-5 until the pH reaches 3.8~4.2. At this time, the circulation pump 143 is turned off, and the first liquid outlet solenoid valve 149 is opened to inject the treated acidic mine wastewater into the iron precipitation tank 16 through the first connecting pipe 17. After a period of injection, the first liquid outlet solenoid valve 149 is automatically closed under the action of the timer inside the control panel 32. Then the above steps are repeated to continue the treatment until the iron precipitation material in the iron precipitation tank 16 reaches the monitoring height of the mud level monitor 111. At this time, the end of the first connecting pipe 17 is placed into another iron precipitation tank 16 to continue the treatment. The iron precipitation tank where the iron precipitation material reaches the monitoring height of the mud level monitor 111 will proceed to the next step.

[0053] S4. When the height of the iron precipitate reaches the monitoring height of the mud level monitor 111, the pump 151 of the second conveying mechanism 22 is automatically started to inject the iron-removed acidic mine wastewater above the iron precipitate in the iron precipitation tank 16 into the neutralization tower 211. The iron-removed acidic mine wastewater is sprayed through the neutralization nozzle 212, so that the iron-removed acidic mine wastewater can fully react with the neutralizing agent 214 inside the neutralization chamber 213. After the reaction, the mine wastewater is obtained. At this time, the mine wastewater flows through the 0.5cm~1cm output hole 215 at the bottom of the neutralization chamber 213 to the collection chamber 216 and through the second connecting pipe 24 to the neutralization sedimentation tank 23. After a period of sedimentation, the treated supernatant and precipitate are obtained.

[0054] S5. The supernatant obtained after treatment in the neutralization sedimentation tank 23 is transported to a suitable place through the third conveying mechanism 25 for utilization or discharge. The sediment obtained after treatment in the neutralization sedimentation tank 23 is transported to the goaf and roadway in the lower mine through the siphon mechanism 26 for backfilling. Under the control of the control panel 32, the treatment can be carried out continuously.

[0055] Example 3

[0056] This embodiment (which assumes the system is fully assembled) describes the processing results obtained after using the system in the following four specific scenarios:

[0057] Specific example 1

[0058] The acidic mine wastewater to be treated is processed through the system described in this invention via the following steps and processes:

[0059] S1: Operate control panel 32 to turn on air compressor 147-2 and ammonia tank 147-1 valve, then introduce both into mixing chamber 147-3 for mixing, and finally introduce the mixed gas into the reaction tower; the ammonia flow rate is 3L / s;

[0060] S2: Start the water pump to pump the acidic mine wastewater to the equalization tank 11. After preliminary sedimentation, turn on the liquid pump 151 of the first conveying mechanism 15 to pass the acidic mine wastewater into the reaction tower. The flow rate of the acidic mine wastewater is 2L / s.

[0061] S3: Open the first discharge solenoid valve 149 and inject the acidic mine wastewater with pH adjusted to 3.8~4.2 after treatment into the iron sedimentation tank 16 through the first connecting pipe 17. The retention time is 4~5 hours. The remaining sludge at the bottom is extracted to obtain iron-rich remaining sludge, the main metal component of which is iron hydroxide.

[0062] S4: Turn on the pump 151 of the second conveying mechanism 22. The acidic mine wastewater after iron removal flows through the delivery pipe 152 to the neutralization nozzle 212. The spray flow rate of the neutralization nozzle 212 is 1L / s~3L / s. The neutralizing agent is a mixture of calcite, dolomite, calcium hydroxide and flocculant in a ratio of 60%:20%:15%:5%.

[0063] S5: The acidic mine wastewater that has been reacted with the neutralizing agent and removed iron enters the neutralization sedimentation tank 23 through the second connecting pipe 24. The lower sediment is discharged to the goaf and roadway in the lower mine through the siphon pipe. The supernatant is discharged from the mine through the third conveying mechanism 25 and collected for testing of heavy metals and pH.

[0064] Specific example 2

[0065] The acidic mine wastewater to be treated is passed through the system and treated through the following steps and processes:

[0066] S1: Operate control panel 32 to turn on air compressor 147-2 and open valve of ammonia tank 147-1, and introduce both into mixing box 147-3 for mixing. After mixing, introduce the mixture into reaction tower; the ammonia flow rate is 3L / s.

[0067] S2: Start the water pump to pump the acidic mine wastewater to the equalization tank 11. After preliminary sedimentation, turn on the liquid pump 151 of the first conveying mechanism 15 to pass the acidic mine wastewater into the reaction tower. The flow rate of the acidic mine wastewater is 2L / s.

[0068] S3: Open the first discharge solenoid valve 149 and inject the acidic mine wastewater with pH adjusted to 3.8~4.2 after treatment into the iron sedimentation tank 16 through the first connecting pipe 17. The retention time is 4~5 hours. The remaining sludge at the bottom is extracted to obtain iron-rich remaining sludge, the main metal component of which is iron hydroxide.

[0069] S4: Turn on the pump 151 of the second conveying mechanism 22. The acidic mine wastewater after iron removal flows through the delivery pipe 152 to the neutralization nozzle 212. The spray flow rate of the neutralization nozzle 212 is 1L / s~3L / s. The neutralizing agent is a mixture of calcite, dolomite, calcium hydroxide and flocculant in a ratio of 60%:20%:5%:15%.

[0070] S5: The acidic mine wastewater that has been reacted with the neutralizing agent and removed iron enters the neutralization sedimentation tank 23 through the second connecting pipe 24. The lower sediment is discharged to the goaf and roadway in the lower mine through the siphon pipe. The supernatant is discharged from the mine through the third conveying mechanism 25 and collected for testing of heavy metals and pH.

[0071] Specific example 3

[0072] The acidic mine wastewater to be treated is passed through the system and treated through the following steps and processes:

[0073] S1: Operate control panel 32 to turn on air compressor 147-2 and open valve of ammonia tank 147-1, and introduce both into mixing box 147-3 for mixing. After mixing, introduce the mixture into reaction tower; the ammonia flow rate is 3L / s.

[0074] S2: Start the water pump to pump the acidic mine wastewater to the equalization tank 11. After preliminary sedimentation, turn on the liquid pump 151 of the first conveying mechanism 15 to pass the acidic mine wastewater into the reaction tower. The flow rate of the acidic mine wastewater is 2L / s.

[0075] S3: Open the first discharge solenoid valve 149 and inject the acidic mine wastewater with pH adjusted to 3.8~4.2 after treatment into the iron sedimentation tank 16 through the first connecting pipe 17. The retention time is 4~5 hours. The remaining sludge at the bottom is extracted to obtain iron-rich remaining sludge, the main metal component of which is iron hydroxide.

[0076] S4: Turn on the pump 151 of the second conveying mechanism 22. The acidic mine wastewater after iron removal flows through the delivery pipe 152 to the neutralization nozzle 212. The spray flow rate of the neutralization nozzle 212 is 1L / s~3L / s. The neutralizing agent is a mixture of calcite, dolomite, calcium hydroxide and flocculant in a ratio of 60%:20%:10%:10%.

[0077] S5: The acidic mine wastewater that has been reacted with the neutralizing agent and removed iron enters the neutralization sedimentation tank 23 through the second connecting pipe 24. The lower sediment is discharged to the goaf and roadway in the lower mine through the siphon pipe. The supernatant is discharged from the mine through the third conveying mechanism 25 and collected for testing of heavy metals and pH.

[0078] Specific example 4

[0079] The acidic mine wastewater to be treated is passed through the system and treated through the following steps and processes:

[0080] S1: Operate control panel 32 to turn on air compressor 147-2 and open valve of ammonia tank 147-1, and introduce both into mixing box 147-3 for mixing. After mixing, introduce the mixture into reaction tower; the ammonia flow rate is 3L / s.

[0081] S2: Start the water pump to pump the acidic mine wastewater to the equalization tank 11. After preliminary sedimentation, turn on the liquid pump 151 of the first conveying mechanism 15 to pass the acidic mine wastewater into the reaction tower. The flow rate of the acidic mine wastewater is 2L / s.

[0082] S3: Open the first discharge solenoid valve 149 and inject the acidic mine wastewater with pH adjusted to 3.8~4.2 after treatment into the iron sedimentation tank 16 through the first connecting pipe 17. The retention time is 4~5 hours. The remaining sludge at the bottom is extracted to obtain iron-rich remaining sludge, the main metal component of which is iron hydroxide.

[0083] S4: Turn on the pump 151 of the second conveying mechanism 22. The acidic mine wastewater after iron removal flows through the delivery pipe 152 to the neutralization nozzle 212. The spray flow rate of the neutralization nozzle 212 is 1L / s~3L / s. The neutralizing agent is a mixture of calcite, dolomite, calcium hydroxide and flocculant in a ratio of 60%:15%:20%:5%.

[0084] S5: The acidic mine wastewater that has been reacted with the neutralizing agent and removed iron enters the neutralization sedimentation tank 23 through the second connecting pipe 24. The lower sediment is discharged to the goaf and roadway in the lower mine through the siphon pipe. The supernatant is discharged from the mine through the third conveying mechanism 25 and collected for testing of heavy metals and pH.

[0085] category Specific example 1 Specific example 2 Specific example 3 Specific example 4 Inlet water pH 2.89 2.89 2.89 2.89 Influent iron concentration (mg / L) 612.78 612.78 612.78 612.78 Influent manganese concentration (mg / L) 22.60 22.60 22.60 22.60 effluent pH 7.28 7.45 7.72 8.23 Iron concentration in effluent (mg / L) 12.26 8.8 4.29 3.24 Manganese concentration in effluent (mg / L) 0.46 0.41 0.38 0.34 Iron removal rate (%) 98.0 98.9 99.2 99.47 Manganese removal rate (%) 97.96 98.18 98.31 98.49

[0086] Table 1 Measurement Results

[0087] It can be seen that after systematic treatment by the specific examples of the present invention, the pH of the effluent in each specific example increased, indicating that the system and process of the present invention can significantly improve the pH of acidic mine wastewater. When acidic mine wastewater containing high concentrations of iron and manganese was treated by the specific examples of the present invention, a comparison of the four groups of specific examples revealed that although the removal effect of iron and manganese in specific example 4 was better, the pH was quite high, and acid adjustment was still required. The comprehensive treatment effect of specific example 3 was significantly stronger than the other three groups of examples, with an effluent iron ion concentration of 4.29 mg / L and a manganese ion concentration of 0.38 mg / L, and a comprehensive treatment efficiency of 99.2% for iron ions and 99.31% for manganese ions. This indicates that the present invention can achieve a very high efficiency in reducing the pH of acidic mine wastewater and removing iron and manganese therein.

Claims

1. An acidic mine wastewater treatment system, comprising an iron removal device (1), a neutralization device (2), and a control device (3), characterized in that: The iron removal device (1) includes an equalization tank (11), an injection pipe (12) located at the side of the equalization tank (11), a sludge discharge pipe (13) located at the bottom of the equalization tank (11), a reaction mechanism (14) located next to the equalization tank (11), a first conveying mechanism (15) connecting the reaction mechanism (14) and the equalization tank (11), an iron precipitation tank (16) located next to the reaction mechanism (14), and a first connecting pipe (17) connecting the reaction mechanism (14) and the iron precipitation tank (16). The neutralization device (2) includes a neutralization mechanism (21) disposed next to the iron sedimentation tank (16), a second conveying mechanism (22) connecting the iron sedimentation tank (16) and the neutralization mechanism (21), a neutralization sedimentation tank (23) disposed next to the neutralization mechanism (21), a second connecting pipe (24) connecting the neutralization mechanism (21) and the neutralization sedimentation tank (23), and a third conveying mechanism (25) and a siphon mechanism (26) disposed on one side of the neutralization sedimentation tank (23). The reaction mechanism (14) includes a reaction tower (141), multiple reaction nozzles (142) equidistantly arranged in a circular pattern at the top of the inside of the reaction tower (141), a circulation pump (143) located at the bottom of the inside of the reaction tower (141), a circulation pipe (144) with a check valve fixedly connected to the output end of the circulation pump (143) and the main pipe of the reaction nozzles (142), a pH sensor (145) and a liquid level sensor (146) located on the side wall inside the reaction tower (141), an ammonia injection mechanism (147) installed on the side wall of the reaction tower (141), and a circulation pipe (144) with a check valve located at the bottom of the reaction tower (141). The outlet (148) of the first liquid outlet solenoid valve (149) is provided; the ammonia injection mechanism (147) includes an ammonia tank (147-1), an air compressor (147-2) and a mixing tank (147-3). The mixing tank (147-3) is equipped with a concentration sensor (147-4) to monitor and control the ratio of ammonia to air to 2-4:3-6 in real time. The mixed gas is injected into the lower part of the reaction tower (141) through a gas pipe with an aeration head (147-6). The unreacted gas is returned to the mixing tank (147-3) for recycling through a return pipe with a check valve (147-5). The neutralization mechanism (21) includes a neutralization tower (211), multiple neutralization nozzles (212) equidistantly arranged in a circular pattern at the top of the neutralization tower (211), a neutralization chamber (213) located in the middle of the neutralization tower (211), a neutralizing agent (214) installed inside the neutralization chamber (213), output holes (215) equidistantly and uniformly arranged at 0.5cm to 1cm at the bottom of the neutralization chamber (213), and a collection chamber (216) located at the bottom of the neutralization tower (211); the neutralizing agent (214) is a mixture of calcite, dolomite, calcium hydroxide and flocculant, with particle sizes of 2 to 3cm for calcite, 1 to 2cm for dolomite and 1 to 2cm for calcium hydroxide; One end of the siphon mechanism (26) is connected to the bottom sediment outlet of the neutralization sedimentation tank (23), and the other end extends to the goaf or roadway of the abandoned mine. It is used to directly transport the sediment generated in the neutralization sedimentation tank (23) to the goaf or roadway for backfilling, so as to support the mine structure and prevent geological disasters. The control device (3) includes a workbench (31), a control panel (32) located on the upper end of the workbench (31), a solar panel (33), and a battery (34) installed inside the workbench (31). The control panel (32) is equipped with a control unit, an alarm, and a timer, and has a display screen and control knobs on its outer surface. The side walls of the equalization tank (11), the iron sedimentation tank (16), and the neutralization sedimentation tank (23) are all equipped with sludge level monitors (111). The sludge level monitors (111) and pH sensors are also included. The device (145), liquid level sensor (146), concentration sensor (147-4), circulation pump (143), first liquid outlet solenoid valve (149), and liquid pumps (151) of each conveying mechanism are all electrically connected to the control panel (32); the pH value in the reaction tower (141) is precisely controlled within the range of 3.8 to 4.2, and the start and stop of each liquid pump (151) and siphon mechanism (26) are automatically controlled according to the monitoring signal of the mud level monitor (111), so as to realize the automation of mud-water separation and in-situ backfilling of sediment.

2. The acidic mine wastewater treatment system according to claim 1, characterized in that: The reaction tower (141) is equipped with an internal circulating spray circuit consisting of a circulating pump (143), a circulating pipe (144) with a one-way valve, and a reaction nozzle (142), which allows the acidic mine wastewater to fully contact and react with the ammonia-air mixture. The unreacted gas is returned to the mixing tank (147-3) for recycling through a return pipe (147-5) with a check valve.

3. The acidic mine wastewater treatment system according to claim 1, characterized in that: The solar panel (33) and battery (34) provide power to the control panel (32) and various electrical connection elements.

4. The acidic mine wastewater treatment system according to claim 1, characterized in that: The mass percentages of each component in the neutralizer (214) are: calcite 60%, dolomite 20%, calcium hydroxide 10%, and flocculant 10%.

5. The acidic mine wastewater treatment system according to claim 1, characterized in that: The pumps (151) of the first conveying mechanism (15), the second conveying mechanism (22) and the third conveying mechanism (25) are all installed at a height higher than the monitoring height of the mud level monitor (111) in the corresponding pool, so as to ensure that the liquid extracted is the upper clear liquid.

6. A method for treating acidic mine wastewater using the system according to any one of claims 1-5, characterized in that... Includes the following steps: S1. After the acidic mine wastewater is injected into the regulating tank (11) for preliminary sedimentation, it is pumped into the reaction tower (141) through the first conveying mechanism (15). At the same time, the control device (3) automatically adjusts the flow rate of the ammonia tank (147-1) and the air compressor (147-2) according to the feedback of the concentration sensor (147-4), so that the ammonia and air are mixed at a volume ratio of 2-4:3-6 and injected into the reaction tower (141). The wastewater is circulated and sprayed through the circulating pump (143) and the reaction nozzle (142) until the pH sensor (145) detects that the pH value in the reaction tower (141) reaches 3.8-4.

2. At this time, the circulating pump (143) is turned off and the first liquid discharge solenoid valve (149) is opened. The treated wastewater is discharged into the iron precipitation tank (16) through the first connecting pipe (17) and allowed to settle to obtain iron hydroxide precipitate and manganese-containing supernatant. S2. When the sludge level in the iron sedimentation tank (16) reaches the set height of the sludge level monitor (111), the second conveying mechanism (22) is activated to pump the supernatant of the iron sedimentation tank (16) into the neutralization tower (211), and spray it into the neutralization chamber (213) through the neutralization nozzle (212) so that the wastewater and the neutralizing agent (214) can fully react. The wastewater after reaction flows into the collection chamber (216) through the output hole (215), and then enters the neutralization sedimentation tank (23) through the second connecting pipe (24). After sedimentation, the supernatant and heavy metal precipitate are obtained. S3. Discharge the supernatant of the neutralization sedimentation tank (23) through the third conveying mechanism (25), and at the same time start the siphon mechanism (26) to use the siphon force to directly transport the sediment at the bottom of the neutralization sedimentation tank (23) to the goaf area or roadway of the abandoned mine for backfilling. The start-up, shutdown, and parameter adjustment of the pumps, valves, and sensors described in S1-S3 are all automatically completed by the solar-powered control device (3).

7. The method according to claim 6, characterized in that: In step S1, the unreacted ammonia-air mixture is returned to the mixing tank (147-3) via the return pipe (147-5) with a check valve for recycling, thereby improving the utilization rate of ammonia.

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