Manganese slag percolate ammonia nitrogen resourceful treatment system

Abstract

The utility model discloses a resourceful treatment system for ammonia nitrogen of manganese slag percolate. The resourceful treatment system comprises a water collecting tank, a manganese precipitation reaction tank, a first filter pressing device, a hardness removal reaction tank, a second filter pressing device, an intermediate water tank, a precise filtering device, an ultrafiltration device, a gaseous membrane deamination device, a bipolar membrane electrodialysis device, a rectification device and a multi-effect membrane distillation device which are sequentially connected in series. Manganese residue leachate obtained after manganese precipitation, hardness removal and filtration enters a gaseous membrane method deamination device, ammonia nitrogen in the leachate is removed to reach the standard to be recycled, a by-product ammonium sulfate solution is treated through a bipolar membrane electrodialysis device to obtain dilute ammonia water and dilute sulfuric acid, the dilute ammonia water is rectified, concentrated and recycled in electrolytic manganese production, and the dilute sulfuric acid is recycled. Dilute sulphuric acid is concentrated by the multi-effect membrane distillation device and then returns to the gaseous membrane deamination device to be recycled as an absorbent. According to the device, ammonia nitrogen in the manganese residue leachate can be removed to reach the standard, ammonia nitrogen resource recycling is realized, and the process is water-saving, energy-saving and efficient.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial wastewater treatment, in particular to a system for resource processing of ammonia nitrogen in manganese slag leachate. Background Art

[0002] Manganese slag is an industrial waste residue produced in the process of producing metallic manganese after acid leaching, ammonia neutralization, and filter pressing. At present, it is treated by stacking in manganese slag warehouses. During the storage process, leachate is formed under the erosion of rainwater and its own infiltration. The manganese slag leachate contains high concentrations of pollutants such as manganese, magnesium, and ammonia nitrogen, which causes serious pollution to the surrounding soil and groundwater. The industry generally adopts calcium hydroxide to precipitate manganese pretreatment, and then uses a stripping-absorption process to remove ammonia from the leachate; this process is not only energy-intensive, but also difficult to treat to meet the standards under low temperatures and low feed ammonia nitrogen concentrations. How to harmlessly and resourcefully treat the absorbed liquid enriched with ammonia nitrogen should also be considered.

[0003] The gaseous membrane process is used to treat the pre-treated manganese slag leachate (such as CN113955872A), and sulfuric acid is often used as an absorbent to obtain the deammoniation liquid reuse and ammonium sulfate solution byproduct; the ammonium sulfate solution can be reused in the electrolytic manganese production process, but the utilization rate is limited, and the excess ammonium sulfate needs to be further concentrated and crystallized for export; and the gaseous membrane deammoniation process requires the consumption of sulfuric acid, and the overall reagent consumption is large. Using a reversible absorbent (such as CN04211244A), the gaseous membrane process can recycle ammonia water, but it will introduce new impurities. Although the gaseous membrane method can treat the manganese slag leachate to meet the standards, it is difficult to fully recycle the ammonia nitrogen in the manganese slag leachate. Utility Model Content

[0004] In order to overcome the shortcomings of the existing manganese slag leachate ammonia nitrogen removal and recovery technology and improve the resource treatment and reuse rate of ammonia nitrogen in manganese slag leachate, the utility model provides a manganese slag leachate ammonia nitrogen resource treatment system, the leachate is subjected to manganese precipitation and hardness removal pretreatment, and then ammonia nitrogen in the feed liquid is removed by a gas membrane method to achieve standard reuse of manganese slag leachate, the by-product ammonium sulfate solution is treated by bipolar membrane electrodialysis to obtain dilute ammonia water and dilute sulfuric acid, the dilute sulfuric acid is concentrated by multi-effect membrane distillation and reused as a gas membrane process absorbent; the ammonia water is concentrated by distillation and reused in the manganese production process.

[0005] To achieve the above object, the present utility model proposes the following technical solution: A system for resource treatment of ammonia nitrogen in manganese slag leachate, comprising a collecting tank (1), a manganese precipitation reaction tank (2), a first pressure filtration device (3), a dehardening reaction tank (4), a second pressure filtration device (5), an intermediate water tank (6), a precision filtration device (7), an ultrafiltration device (8), a gaseous membrane ammonia removal device, a bipolar membrane electrodialysis device (14), a multi-effect membrane distillation device, and a rectification device, which are connected in series in sequence; the above system devices are connected by matching liquid transfer pumps, pipelines, valves and instruments;

[0006] The ultrafiltration device (8) is provided with an ultrafiltration membrane unit and an ultrafiltration product water tank (9). The water produced by the precision filter enters the ultrafiltration product water tank (9) after being filtered by the ultrafiltration membrane unit, and the concentrated water produced by the ultrafiltration membrane unit returns to the dehardening reaction tank (4);

[0007] The gaseous membrane device is provided with a gaseous membrane unit (10), an acid liquid circulation tank (11), an ammonium sulfate tank (12), and an external discharge tank (13). The feed port of the gaseous membrane unit (10) is connected to the water outlet of the ultrafiltration product water tank (9) through a pipeline, the acid inlet of the gaseous membrane unit (10) is connected to the acid outlet of the acid liquid circulation tank (11), the acid liquid circulation tank (11) is also provided with a concentrated sulfuric acid feed port and a sulfuric acid concentrate feed port produced by the multi-effect membrane distillation device, the acid outlet of the gaseous membrane unit (10) is connected to the feed port of the ammonium sulfate tank (12), the discharge port of the gaseous membrane unit (10) is connected to the liquid inlet of the external discharge tank (13), and the gaseous membrane unit (10) includes a plurality of gaseous membrane components arranged in series or in parallel;

[0008] The feed port of the bipolar membrane electrodialysis device (14) is connected to the discharge port of the ammonium sulfate tank (12) through a liquid transfer pump and a pipeline. The bipolar membrane electrodialysis device (14) is provided with an ammonia water discharge port and a sulfuric acid discharge port, which are respectively connected to an ammonia water tank (16) and a sulfuric acid tank (15) through pipelines.

[0009] Furthermore, in the present utility model, the multi-effect membrane distillation device is provided with a multi-effect membrane distillation unit (17) and a heat exchanger (18). The feed port of the multi-effect membrane distillation unit (17) is connected to the discharge port of the sulfuric acid tank (15) through a liquid transfer pump and a pipeline. A heat exchanger (18) is connected in series between the inlet and the outlet of the return water end of the multi-effect membrane distillation unit (17). The discharge port of the multi-effect membrane distillation is connected to the acid liquid circulation tank (11) of the gaseous membrane device; the multi-effect membrane distillation unit (17) includes a plurality of multi-effect membrane distillation components arranged in series or in parallel, and a distillate outlet is provided at the lower end of the membrane shell of the multi-effect membrane distillation component.

[0010] Further, in the present utility model, the rectification device is provided with a rectification column (20), a preheater (19), a condenser (21), a reflux pump (22), and a concentrated ammonia water storage tank (23). The bottom of the rectification column (20) is provided with a liquid outlet and a steam inlet, the middle part is provided with a liquid inlet, and the top of the column is provided with a steam outlet and a reflux ammonia water inlet; the liquid inlet of the rectification column (20) is connected to the outlet of the ammonia water tank (16) through a liquid delivery pump and a pipeline, and a preheater (19) is arranged between the ammonia water tank (16) and the rectification column (20), and the preheater (19) is communicated with the liquid outlet at the bottom of the rectification column (20) and the ultrafiltration produced water tank (9); the gas outlet at the top of the rectification column (20) is connected to a condenser (21), and the condenser (21) is connected to the reflux ammonia water inlet of the rectification column (20) through a reflux pump (22); the condenser (21) is also connected to the concentrated ammonia water storage tank (23).

[0011] Further, in the present utility model, the water inlet of the manganese precipitation reaction tank (2) is connected to the water outlet of the collection tank (1) through a liquid delivery pump and a pipeline, and the water outlet is connected to the feed inlet of the first pressure filtration device (3). The manganese precipitation reaction tank (2) is provided with a stirring device, a pH meter, and a lime milk feeding port.

[0012] Further, in the present utility model, the feed inlet of the hardening removal reaction tank (4) is connected to the discharge outlet of the first pressure filtration device (3) through a pipeline, and the water outlet is connected to the feed inlet of the second pressure filtration device (5). The hardening removal reaction tank (4) is provided with a stirring device, a sodium carbonate solution feed inlet, and an ultrafiltration concentrated water inlet.

[0013] Further, in the present utility model, both the first pressure filtration device (3) and the second pressure filtration device (5) are provided with filter residue outlets.

[0014] Further, in the present utility model, the discharge outlet of the second pressure filtration device (5) is connected to the feed inlet of the intermediate water tank (6) through a pipeline, and a turbidimeter is arranged on the pipeline.

[0015] Further, in the present utility model, pH meters for detecting the acidity of the feed liquid are provided on the acid liquid circulation tank (11), the gaseous membrane acid outlet pipeline, the discharge tank (13), and the ammonium sulfate tank (12).

[0016] Further, in the present utility model, ammonia nitrogen detectors are provided on the feed pipeline of the gaseous membrane unit (10) and the gaseous membrane discharge outlet pipeline of the gaseous membrane device.

[0017] Further, in the present utility model, pressure gauges for measuring the hydraulic pressure are provided on the pipelines behind all the liquid delivery pumps.

[0018] Advantageous effects: The technical solution of the present application has the following technical effects:

[0019] 1. After the manganese slag leachate is pretreated by manganese precipitation, hardness removal, and filtration, the ammonia nitrogen in the feed liquid can be removed to meet the standards by the gas membrane method ammonia removal device and reused.

[0020] 2. The by-product ammonium sulfate solution formed by the gas membrane method ammonia removal is processed by a bipolar membrane electrodialysis device to generate sulfuric acid solution. The sulfuric acid solution is concentrated by a multi-effect membrane distillation device, and the concentrated sulfuric acid solution is returned to the acid liquid circulation tank of the gas membrane ammonia removal device and continues to be used for gas membrane method ammonia removal; the dilute ammonia water is concentrated by a rectification device and then returned to the manganese production process, thus realizing the reuse of the medicament and greatly reducing the medicament cost.

[0021] 3. While efficiently removing ammonia nitrogen from the manganese slag leachate, the present utility model realizes the resource treatment of ammonia and improves the wastewater utilization rate.

[0022] 4. The present utility model takes energy-saving and efficient devices such as gas membrane, bipolar membrane electrodialysis, multi-effect membrane distillation, and rectification as the main body, and the manganese slag leachate ammonia nitrogen resource treatment system is overall energy-saving and efficient.

[0023] It should be understood that all combinations of the foregoing concepts and additional concepts described in more detail below can be regarded as part of the inventive subject matter of the present disclosure as long as such concepts do not conflict with each other.

[0024] The foregoing and other aspects, embodiments, and features of the teachings of the present utility model can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present utility model, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or will be learned through the practice of the specific embodiments according to the teachings of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in each figure may be represented by the same reference numeral. For clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present utility model will be described by way of example and with reference to the drawings, wherein:

[0026] Figure 1 is a schematic structural diagram of the present utility model.

[0027] The reference numerals in the figure are: 1. collecting tank; 2. manganese precipitation reaction tank; 3. first pressure filtration device; 4. dehardening reaction tank; 5. second pressure filtration device; 6. intermediate water tank; 7. precision filtration device; 8. ultrafiltration device; 9. ultrafiltration product water tank; 10. gas membrane unit; 11. acid liquid circulation tank; 12. ammonium sulfate tank; 13. external discharge tank; 14. bipolar membrane electrodialysis device; 15. sulfuric acid tank; 16. ammonia water tank; 17. multi-effect membrane distillation unit; 18. heat exchanger; 19. preheater; 20. rectifying column; 21. condenser; 22. reflux pump; 23. concentrated ammonia water storage tank. Detailed implementation manners

[0028] In order to better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows. In the present disclosure, aspects of the present invention are described with reference to the drawings, and many illustrative embodiments are shown in the drawings. The embodiments of the present disclosure do not necessarily define all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of a number of ways, because the concepts and embodiments disclosed in the present invention are not limited to any implementation manner. In addition, some aspects of the present invention disclosed can be used alone, or in any suitable combination with other aspects of the present invention disclosed.

[0029] As Figure 1 shown, the ammonia nitrogen resource treatment system for manganese slag leachate of the present invention comprises a collecting tank 1, a manganese precipitation reaction tank 2, a first pressure filtration device 3, a dehardening reaction tank 4, a second pressure filtration device 5, an intermediate water tank 6, a precision filtration device 7, an ultrafiltration device 8, a gas membrane ammonia removal device, a bipolar membrane electrodialysis device 14, a multi-effect membrane distillation device, and a rectifying device, which are connected in series in sequence. The above system devices are connected by means of matching liquid transfer pumps, pipelines, valves and instruments.

[0030] The specific process is as follows: After the manganese slag leachate converges into the collection tank 1, it enters the manganese precipitation reaction tank 2 through a liquid transfer pump. Lime milk is added to the reaction tank. The pH of the feed liquid is monitored by a pH meter to be > 11. The stirring device makes the manganese slag leachate and lime milk mix evenly, react fully, and improve the manganese precipitation effect. Then it enters the first pressure filtration device 3. The clear liquid after pressure filtration enters the dehardening reaction tank 4. The manganese-containing waste residue is regularly discharged through the filter residue outlet and transported to a slag yard that has not been closed. Sodium carbonate is added to the dehardening reaction tank 4. The stirring device makes the feed liquid and sodium carbonate mix evenly, react fully, and improve the dehardening effect. Then it enters the second filtration device 5. The clear liquid after filtration enters the intermediate water tank 6 after being monitored for turbidity by a turbidimeter. The calcium- and magnesium-containing waste residue is regularly discharged through the filter residue outlet and transported to a slag yard that has not been closed. The feed liquid in the intermediate water tank 6 enters the precision filtration device 7 through a liquid transfer pump for filtration. The filtered feed liquid enters the ultrafiltration device 8. The ultrafiltration device 8 includes an ultrafiltration membrane unit. The ultrafiltration produced water enters the ultrafiltration produced water tank 9. The concentrated water after ultrafiltration returns to the dehardening reaction tank 4.

[0031] In the gaseous membrane ammonia stripping device, the ammonia-nitrogen-containing feed liquid in the ultrafiltration produced water tank 9 enters the tube side of the gaseous membrane unit 10, and the sulfuric acid solution in the acid liquid circulation tank 11 enters the shell side of the gaseous membrane unit 10. The volatile ammonia in the feed liquid permeates through the microporous hydrophobic gaseous membrane and is absorbed by the sulfuric acid solution on the other side to generate ammonium sulfate, thereby removing ammonia-nitrogen from the feed liquid. After detecting the ammonia-nitrogen in the feed liquid, it enters the discharge tank 13. After adding an appropriate amount of concentrated sulfuric acid to adjust the pH value of the feed liquid to neutral, it is recycled; Whether the ammonium sulfate solution returns to the acid liquid circulation tank 11 is judged by the pH of the acid outlet pipeline of the gaseous membrane unit 10 and controlled by the opening and closing of the pipeline valve. When pH < 2, it returns to the acid liquid circulation tank 11 for recycling as the acidic absorption liquid. When pH > 2, it enters the ammonium sulfate tank 12.

[0032] An appropriate amount of ammonia water is added to the ammonium sulfate tank 12, and the ammonium sulfate solution is adjusted to neutral and then enters the bipolar membrane electrodialysis device 14. Under the action of the bipolar membrane in the direct current electric field, dilute sulfuric acid and dilute ammonia water with low concentrations are generated and discharged into the sulfuric acid tank 15 and the ammonia water tank 16 respectively.

[0033] The dilute ammonia water enters the preheater 19 and exchanges heat with the treated bottom outlet water (high-temperature water). The preheated dilute ammonia water enters the rectification tower 20 through the liquid inlet in the middle of the rectification tower 20 and contacts the steam from the bottom of the rectification tower 20 reversely. Since the volatility of ammonia is greater than that of water, through mass transfer under the action of steam stripping, more ammonia enters the gas phase and enters the condenser 21 from the steam outlet at the top of the tower. The ammonia-containing steam is liquefied into an ammonia water solution and then returned to the rectification tower 20 by the reflux pump 22. When the concentration of the condensed ammonia water reaches the required concentration, it is transported to the concentrated ammonia water storage tank 23; The bottom outlet water (high-temperature water), still containing a low concentration of ammonia-nitrogen, enters the ultrafiltration produced water tank through the preheater 19 for further ammonia stripping.

[0034] Dilute sulfuric acid enters from the feed port at the lower part of the multi-effect membrane distillation unit 17, flows out from the discharge port of the multi-effect membrane distillation unit 17 after being heated by the heat exchanger 18 at the return water end of the multi-effect membrane distillation. The latent heat of the temperature difference of the liquid before and after heat exchange is used to concentrate the dilute sulfuric acid. The concentrated sulfuric acid is returned to the acid liquid circulation tank 11 for recycling, and the distilled liquid generated in the shell side of the multi-effect membrane distillation unit 17 can be recycled.

[0035] The standard parts used in this application document can all be purchased from the market, and can also be customized according to the descriptions in the specification and drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment all adopt conventional models in the prior art. The control method is automatically controlled by a controller, and the control circuit of the controller can be realized by simple programming by those skilled in the art, which belongs to the common knowledge in this field. And this application document is mainly used to protect mechanical devices, so the control method and circuit connection will not be explained in detail in this application document.

[0036] Although the present utility model has been disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Those with ordinary knowledge in the technical field to which the present utility model pertains can make various modifications and refinements without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to that defined by the claims.

Claims

1. A resource treatment system for ammonia nitrogen in manganese slag leachate, characterized in that It includes a collecting tank (1), a manganese precipitation reaction tank (2), a first pressure filtration device (3), a dehardening reaction tank (4), a second pressure filtration device (5), an intermediate water tank (6), a precision filtration device (7), an ultrafiltration device (8), a gaseous membrane ammonia removal device, a bipolar membrane electrodialysis device (14), a multi-effect membrane distillation device, and a rectification device connected in series in sequence. The system devices are connected by supporting liquid transfer pumps, pipelines, valves, and instruments; The ultrafiltration device (8) is provided with an ultrafiltration membrane unit and an ultrafiltration product water tank (9). The water produced by the precision filter enters the ultrafiltration product water tank (9) after being filtered by the ultrafiltration membrane unit, and the concentrated water produced by the ultrafiltration membrane unit returns to the dehardening reaction tank (4); The gaseous membrane ammonia removal device is provided with a gaseous membrane unit (10), an acid solution circulation tank (11), an ammonium sulfate tank (12), and an external discharge tank (13). The feed port of the gaseous membrane unit (10) is connected to the water outlet of the ultrafiltration product water tank (9) through a pipeline. The acid inlet of the gaseous membrane unit (10) is connected to the acid outlet of the acid solution circulation tank (11). The acid solution circulation tank (11) is also provided with a concentrated sulfuric acid feed port and a sulfuric acid concentrate feed port produced by the multi-effect membrane distillation device. The acid outlet of the gaseous membrane unit (10) is connected to the feed port of the ammonium sulfate tank (12). The discharge port of the gaseous membrane unit (10) is connected to the liquid inlet of the external discharge tank (13). The gaseous membrane unit (10) includes several gaseous membrane modules arranged in series or in parallel; The feed port of the bipolar membrane electrodialysis device (14) is connected to the discharge port of the ammonium sulfate tank (12) through a liquid transfer pump and a pipeline. The bipolar membrane electrodialysis device (14) is provided with an ammonia water discharge port and a sulfuric acid discharge port, which are respectively connected to an ammonia water tank (16) and a sulfuric acid tank (15) through pipelines.

2. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that The multi-effect membrane distillation device is provided with a multi-effect membrane distillation unit (17) and a heat exchanger (18). The feed port of the multi-effect membrane distillation unit (17) is connected to the discharge port of the sulfuric acid tank (15) through a liquid transfer pump and a pipeline. A heat exchanger (18) is connected in series between the inlet and the outlet of the return water end of the multi-effect membrane distillation unit (17). The discharge port of the multi-effect membrane distillation is connected to the acid solution circulation tank (11) of the gaseous membrane device; The multi-effect membrane distillation unit (17) includes several multi-effect membrane distillation modules arranged in series or in parallel. A distillate outlet is provided at the lower end of the membrane shell of the multi-effect membrane distillation module.

3. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that The rectification device is provided with a rectification tower (20), a preheater (19), a condenser (21), a reflux pump (22), and a concentrated ammonia water storage tank (23). The bottom of the rectification tower (20) is provided with a liquid outlet and a steam inlet, the middle part is provided with a liquid inlet, and the top of the tower is provided with a steam outlet and a reflux ammonia water inlet; The liquid inlet of the rectification tower (20) is connected to the outlet of the ammonia water tank (16) through a liquid transfer pump and a pipeline. A preheater (19) is arranged between the ammonia water tank (16) and the liquid outlet at the bottom of the rectification tower (20), and the preheater (19) is communicated with the liquid outlet at the bottom of the rectification tower (20) and the ultrafiltration product water tank (9); The gas outlet at the top of the rectification tower (20) is connected to a condenser (21), and the condenser (21) is connected to the reflux ammonia water inlet of the rectification tower (20) through a reflux pump (22); The condenser (21) is also connected to the concentrated ammonia water storage tank (23).

4. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that The water inlet of the manganese precipitation reaction tank (2) is connected to the water outlet of the collection tank (1) through a liquid delivery pump and a pipeline, and the water outlet is connected to the feed inlet of the first pressure filtration device (3). The manganese precipitation reaction tank (2) is equipped with a stirring device, a pH meter, and a lime milk feeding port.

5. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that The feed inlet of the hardening removal reaction tank (4) is connected to the discharge outlet of the first pressure filtration device (3) through a pipeline, and the water outlet is connected to the feed inlet of the second pressure filtration device (5). The hardening removal reaction tank (4) is equipped with a stirring device, a sodium carbonate solution feeding port, and an ultrafiltration concentrated water inlet.

6. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that Both the first pressure filtration device (3) and the second pressure filtration device (5) are provided with filter residue outlets.

7. The ammonia nitrogen resource treatment system for manganese slag leachate according to claim 1, characterized in that The discharge outlet of the second pressure filtration device (5) is connected to the feed inlet of the intermediate water tank (6) through a pipeline, and a turbidimeter is provided on the pipeline.

8. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that pH meters for detecting the acidity of the feed liquid are provided on the acid liquid circulation tank (11), the gaseous membrane acid outlet pipeline, the external discharge tank (13), and the ammonium sulfate tank (12).

9. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that Ammonia nitrogen detectors are provided on the feed pipeline of the gaseous membrane unit (10) and the gaseous membrane discharge outlet pipeline of the gaseous membrane ammonia removal device.

10. The manganese slag leachate ammonia nitrogen resource treatment system according to claim 1, characterized in that Pressure gauges for measuring the hydraulic pressure are provided on the pipelines behind all liquid delivery pumps.

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