Deep treatment process system for strong brine in coal mine

Abstract

The utility model discloses a coal mine strong brine advanced treatment process system, and relates to the technical field of coal mine water treatment. Comprising a high-salinity wastewater pool, a scale inhibitor dosing device, a security filter, an energy recovery high-pressure pump, an STRO device, an STRO concentrated water pool, an STRO water producing pool, a first reaction tank, a sodium carbonate dosing device, a sodium hydroxide dosing device, a flocculant dosing device, a powdered activated carbon dosing device, a second reaction tank, a concentration tank, a tubular membrane device, a polyacrylamide dosing device and a sludge dewatering machine. The device comprises a tubular membrane water producing tank, an acid adding device, a chelating resin tower and an evaporator feeding tank. The device is reasonable in structural design, can realize effective and stable treatment of the mine strong brine, is short in process flow and lower in investment and operation cost, avoids frequent chemical cleaning of the subsequent evaporator, and is beneficial to improving the quality of crystallized salt.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mine water treatment, in particular to a coal mine concentrated brine deep treatment process system. Background Art

[0002] At present, domestic coal mine brine is mostly treated with disc tube reverse osmosis (DTRO) for deep concentration and volume reduction, but this technology has a series of problems such as high investment cost, easy leakage of membrane columns during operation, poor system stability, and cumbersome maintenance. Pipe network reverse osmosis (STRO) is a new reverse osmosis membrane application technology developed in recent years. It has the characteristics of strong pollution resistance, high pressure resistance, high water recovery rate, excellent water quality, and stable system operation. It has been widely used in the fields of landfill leachate and coal chemical wastewater. Therefore, it can replace DTRO within a certain range and effectively solve its outstanding problems. After the concentrated brine in the mine is concentrated, the calcium and magnesium ions in the water are relatively high. Directly entering the evaporation crystallization system is prone to scaling and pipe blockage and reduced thermal efficiency. However, the effect of using tubular membranes alone to soften and remove hardness is often poor. This is mainly because the previous membrane treatment process requires the addition of scale inhibitors to the water. After step-by-step concentration, the concentration of the scale inhibitors will become very high, resulting in the sodium carbonate + sodium hydroxide double alkali method. The softening effect on calcium ions is not ideal, and the removal rate is only 40%-60%, which cannot meet the evaporator feed quality requirements. In this case, the evaporator generally needs chemical cleaning once every six months to one year, and the crystallized salt produced by the system often has more calcium and magnesium impurities, making it difficult to meet the excellent grade standards. In addition, the concentrated brine in the mine often contains a certain concentration of small molecular organic matter, which will cause irreversible fouling and blockage of the tubular membrane in the long run, causing the water output to drop sharply during its operation, and causing the tubular membrane to be unable to work continuously and normally. Utility Model Content

[0003] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a coal mine brine deep treatment process system, which can achieve effective and stable treatment of coal mine brine, and has a short process flow, low investment and operating costs, avoids frequent chemical cleaning of subsequent evaporators, and is beneficial to improving the quality of crystalline salt.

[0004] The technical solution adopted by the utility model to solve the above problems is: a coal mine brine deep treatment process system, including a high-salt wastewater tank, a scale inhibitor dosing device, a security filter, an energy recovery high-pressure pump, a STRO device, a STRO concentrated water tank, a STRO water production tank, a first reaction tank, a sodium carbonate dosing device, a sodium hydroxide dosing device, a flocculant dosing device, a powdered activated carbon dosing device, a second reaction tank, a concentration tank, a tubular membrane device, a polyacrylamide dosing device, a sludge dehydrator, a tubular membrane water production tank, an acid adding device, a chelating resin tower and an evaporator feed tank;

[0005] The water outlet of the high-salt wastewater pool is connected to the water inlet of the security filter, the outlet of the antiscalant dosing device is connected to the water inlet of the security filter, the water outlet of the security filter is connected to the low-pressure water supply inlet of the energy recovery high-pressure pump through a water delivery pipeline, the high-pressure water supply outlet of the energy recovery high-pressure pump is connected to the water inlet of the STRO device through a water inlet pipeline, the concentrated water outlet of the STRO device is connected to the high-pressure concentrated water inlet of the energy recovery high-pressure pump through a concentrated water pipeline, the low-pressure concentrated water outlet of the energy recovery high-pressure pump is connected to the water inlet of the STRO concentrated water tank through a low-pressure concentrated water pipeline, the water production outlet of the STRO device is connected to the STRO water production tank, the water outlet of the STRO concentrated water tank is connected to the water inlet of the first reaction tank, the drug outlets of the sodium carbonate dosing device and the sodium hydroxide dosing device are both connected to the drug inlet of the first reaction tank, the water outlet of the first reaction tank is connected to the water inlet of the second reaction tank, The drug outlets of the flocculant dosing device and the powdered activated carbon dosing device are both connected to the drug inlet of the second reaction tank, the water outlet of the second reaction tank is connected to the water inlet of the concentration tank, the water outlet of the concentration tank is connected to the water inlet of the tubular membrane device, the water production port of the tubular membrane device is connected to the water inlet of the tubular membrane water production pool, the drug outlet of the acid adding device is connected to the drug inlet of the tubular membrane water production pool, the water outlet of the tubular membrane water production pool is connected to the water inlet of the chelating resin tower. The water outlet of the tubular membrane device is connected to the water inlet of the concentration tank, the sludge discharge port of the concentration tank is connected to the sludge inlet of the sludge dewatering machine, the drug outlet of the polyacrylamide dosing device is connected to the sludge inlet of the sludge dewatering machine, the filtrate outlet of the sludge dewatering machine is connected to the water inlet of the STRO concentrated water tank, the water outlet of the chelating resin tower is connected to the water inlet of the evaporator feed tank, and the regenerated wastewater outlet of the chelating resin tower is connected to the water inlet of the STRO concentrated water tank.

[0006] Furthermore, the water outlet of the high-salt wastewater pool is connected to the water inlet of the security filter through a first water supply pump; the concentrate outlet of the STRO device is connected to the water inlet of the first circulation pump through a concentrate pipeline, and the water outlet of the first circulation pump is connected to the water inlet of the STRO device through an inlet pipeline; the water outlet of the STRO concentrate pool is connected to the water inlet of the first reaction tank through a second water supply pump; the water outlet of the concentration tank is connected to the water inlet of the tubular membrane device through a second circulation pump; the sludge discharge port of the concentration tank is connected to the sludge inlet of the sludge dewatering machine through a sludge pump; the water outlet of the tubular membrane water production pool is connected to the water inlet of the chelating resin tower through a third water supply pump.

[0007] Working method: The brine from the coal mine enters the high-salt wastewater pool and is sent to the security filter through the first water supply pump. The scale inhibitor is added to the inlet of the security filter. The effluent is pressurized by the energy recovery high-pressure pump and enters the STRO device for deep concentration treatment. At the same time, the STRO brine pipeline is equipped with a first circulation pump to make most of the brine return to the STRO water inlet pipeline for large-flow circulation treatment, and the other part of the brine enters the high-pressure brine inlet of the energy recovery high-pressure pump. The low-pressure brine after recovering the residual pressure is discharged from the low-pressure brine outlet of the energy recovery high-pressure pump through the low-pressure brine pipeline to the STRO brine pool, and the produced water enters the STRO water production pool. The brine in the STRO brine pool enters the first reaction tank through the second water supply pump, sodium carbonate and sodium hydroxide are added for double alkali softening reaction, and then flows to the second reaction tank, and flocculants and powdered activated carbon are added for coagulation and organic matter adsorption reaction. The effluent enters the concentration tank again, and enters the tubular membrane device through the second circulation pump for membrane filtration treatment. The effluent of the tubular membrane device flows back to the concentration tank. The sludge from the concentration tank is transported to the sludge dewatering machine for dehydration by the sludge pump. Polyacrylamide PAM is added to the sludge inlet of the sludge dewatering machine for conditioning treatment. The filtrate of the sludge dewatering machine is finally discharged into the STRO concentrated water tank for recycling. The water produced by the tubular membrane device enters the tubular membrane water production tank, and after acid is added to adjust the pH, it is sent to the chelating resin tower through the third water supply pump for deep hardness removal. The effluent finally enters the evaporator feed tank. The regenerated wastewater of the chelating resin tower is discharged into the STRO concentrated water tank for recycling.

[0008] This process is specially designed according to the characteristics of concentrated brine water in mines. It has good deep concentration and reduction effects. The STRO device operates stably with low energy consumption. The tubular membrane + chelating resin tower process can achieve deep hardness removal and organic matter removal. The overall operation and maintenance workload of the system is small, and the investment and operation are economical. It can avoid frequent chemical cleaning of the subsequent evaporator and is beneficial to improving the quality of crystalline salt.

[0009] Compared with the prior art, the utility model has the following advantages and effects: (1) The deep concentration of mine brine adopts pipe network reverse osmosis technology (STRO), which can effectively solve the problems of membrane column leakage, cumbersome maintenance, and poor stability; (2) A circulation pump is set in STRO to supplement the pressure loss of the membrane system while controlling the flow rate on the membrane surface within an effective and reasonable range under the action of large flow circulation, thereby greatly reducing membrane fouling and extending the chemical cleaning cycle. An energy recovery high-pressure pump is set in the STRO to recover the waste energy of high-pressure concentrated water and directly convert it into the inlet water. The effective energy conversion efficiency can reach more than 90%, saving more than 50% of electricity costs compared with the system without energy recovery; (3) A certain amount of powdered activated carbon is added to the inlet water of the tubular membrane to adsorb small molecular organic matter in the concentrated brine of the mine, with a removal rate of more than 80%, effectively reducing and delaying the fouling of the tubular membrane, and playing a synergistic role in the double alkali softening method, which is conducive to maintaining a stable water production during operation, so that the tubular membrane can work normally and continuously; (4) An ion exchange process is set up and a chelating resin is used. The resin has good salt resistance and reliable performance. It can achieve fine treatment of residual calcium and magnesium in the concentrated brine, and has a long operation cycle. The effluent fully meets the evaporator feed quality requirements. The chemical cleaning cycle of the evaporator can be extended to more than 3 years, and the produced crystalline salt contains almost no calcium and magnesium impurities, reaching the standard of superior products. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of a concentrated brine deep treatment process system for a coal mine according to the utility model.

[0011] In the figure: high-salt wastewater tank 1, first water supply pump 2, scale inhibitor dosing device 3, security filter 4, water delivery pipeline 5, energy recovery high-pressure pump 6, water inlet pipeline 7, STRO device 8, concentrated water pipeline 9, first circulation pump 10, low-pressure concentrated water pipeline 11, STRO concentrated water tank 12, STRO water production tank 13, second water supply pump 14, first reaction tank 15, sodium carbonate dosing device 16, sodium hydroxide dosing device 17, flocculant dosing device 18, powdered activated carbon dosing device 19, second reaction tank 20, concentration tank 21, second circulation pump 22, tubular membrane device 23, sludge pump 24, polyacrylamide dosing device 25, sludge dewatering machine 26, tubular membrane water production tank 27, acid adding device 28, third water supply pump 29, chelating resin tower 30, evaporator feed tank 31. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0013] See also Figure 1A deep treatment process system for concentrated brine in a coal mine, comprising a high-salt wastewater pool 1, a scale inhibitor dosing device 3, a security filter 4, an energy recovery high-pressure pump 6, a STRO device 8, a STRO concentrated water pool 12, a STRO water production pool 13, a first reaction tank 15, a sodium carbonate dosing device 16, a sodium hydroxide dosing device 17, a flocculant dosing device 18, a powdered activated carbon dosing device 19, a second reaction tank 20, a concentration tank 21, a tubular membrane device 23, a polyacrylamide dosing device 25, a sludge dewatering machine 26, a tubular membrane water production pool 27, an acid adding device 28, a chelating resin tower 30 and an evaporator feed pool 31.

[0014] The water outlet of the high-salt wastewater pool 1 is connected to the water inlet of the security filter 4, the outlet of the antiscalant dosing device 3 is connected to the water inlet of the security filter 4, the water outlet of the security filter 4 is connected to the low-pressure water supply inlet of the energy recovery high-pressure pump 6 through the water delivery pipeline 5, the high-pressure water supply outlet of the energy recovery high-pressure pump 6 is connected to the water inlet of the STRO device 8 through the water inlet pipeline 7, the concentrated water outlet of the STRO device 8 is connected to the high-pressure concentrated water inlet of the energy recovery high-pressure pump 6 through the concentrated water pipeline 9, and the energy recovery The low-pressure concentrated water outlet of the high-pressure pump 6 is connected to the water inlet of the STRO concentrated water tank 12 through the low-pressure concentrated water pipeline 11, the water production outlet of the STRO device 8 is connected to the STRO water production tank 13, the water outlet of the STRO concentrated water tank 12 is connected to the water inlet of the first reaction tank 15, the drug outlets of the sodium carbonate dosing device 16 and the sodium hydroxide dosing device 17 are both connected to the drug inlet of the first reaction tank 15, the water outlet of the first reaction tank 15 is connected to the water inlet of the second reaction tank 20, and the flocculant dosing device The drug outlets of the second reaction tank 20 and the powdered activated carbon dosing device 19 are connected to the drug inlet of the second reaction tank 20, the water outlet of the second reaction tank 20 is connected to the water inlet of the concentration tank 21, the water outlet of the concentration tank 21 is connected to the water inlet of the tubular membrane device 23, the water production port of the tubular membrane device 23 is connected to the water inlet of the tubular membrane water production pool 27, the drug outlet of the acid adding device 28 is connected to the drug inlet of the tubular membrane water production pool 27, and the water outlet of the tubular membrane water production pool 27 is connected to the water inlet of the chelating resin tower 30. The water outlet of the tubular membrane device 23 is connected to the water inlet of the concentration tank 21, the sludge discharge port of the concentration tank 21 is connected to the sludge inlet of the sludge dewatering machine 26, the drug outlet of the polyacrylamide dosing device 25 is connected to the sludge inlet of the sludge dewatering machine 26, the filtrate outlet of the sludge dewatering machine 26 is connected to the water inlet of the STRO concentrated water tank 12, the water outlet of the chelating resin tower 30 is connected to the water inlet of the evaporator feed tank 31, and the regenerated wastewater outlet of the chelating resin tower 30 is connected to the water inlet of the STRO concentrated water tank 12.

[0015] Specifically, the water outlet of the high-salt wastewater pool 1 is connected to the water inlet of the security filter 4 through the first water supply pump 2; the concentrate outlet of the STRO device 8 is connected to the water inlet of the first circulation pump 10 through the concentrate pipeline 9, and the water outlet of the first circulation pump 10 is connected to the water inlet of the STRO device 8 through the water inlet pipeline 7; the water outlet of the STRO concentrate pool 12 is connected to the water inlet of the first reaction tank 15 through the second water supply pump 14; the water outlet of the concentration tank 21 is connected to the water inlet of the tubular membrane device 23 through the second circulation pump 22; the sludge outlet of the concentration tank 21 is connected to the sludge inlet of the sludge dewatering machine 26 through the sludge pump 24; the water outlet of the tubular membrane water production pool 27 is connected to the water inlet of the chelating resin tower 30 through the third water supply pump 29.

[0016] Working method: The concentrated brine of the coal mine enters the high-salt wastewater pool 1, and is sent to the security filter 4 through the first water supply pump 2. The scale inhibitor is added to the inlet of the security filter 4. The effluent is pressurized by the energy recovery high-pressure pump 6 and then enters the STRO device 8 for deep concentration treatment. At the same time, a first circulation pump 10 is provided on the STRO concentrated water pipeline 9 to make most of the concentrated water return to the STRO water inlet pipeline 7 for large-flow circulation treatment, and the other part of the concentrated water enters the high-pressure concentrated water inlet of the energy recovery high-pressure pump 6. The low-pressure concentrated water after recovering the residual pressure is discharged from the low-pressure concentrated water outlet of the energy recovery high-pressure pump 6 through the low-pressure concentrated water pipeline 11 to the STRO concentrated water pool 12, and the produced water enters the STRO produced water pool 13. The concentrated water from the STRO concentrated water tank 12 enters the first reaction tank 15 through the second water supply pump 14, and sodium carbonate and sodium hydroxide are added to perform a double alkali softening reaction, and then flows to the second reaction tank 20, and flocculants and powdered activated carbon are added to perform coagulation and organic matter adsorption reactions, and the effluent enters the concentration tank 21, and enters the tubular membrane device 23 through the second circulation pump 22 for membrane filtration treatment, and the effluent from the tubular membrane device 23 flows back to the concentration tank 21. The sludge from the concentration tank 21 is transported to the sludge dewatering machine 26 for dehydration through the sludge pump 24, and polyacrylamide PAM is added to the mud inlet of the sludge dewatering machine 26 for conditioning treatment. The filtrate of the sludge dewatering machine 26 is finally discharged into the STRO concentrated water tank 12 for recycling. The water produced by the tubular membrane device 23 enters the tubular membrane water production tank 27, and after acid is added to adjust the pH, it is sent to the chelating resin tower 30 for deep hardness removal through the third water supply pump 29, and the effluent finally enters the evaporator feed tank 31. The regenerated wastewater of the chelating resin tower 30 is discharged into the STRO concentrated water tank 12 for recycling. This process is specially designed for the characteristics of the concentrated brine of mine water, and has a good deep concentration and reduction effect. The STRO device 8 operates stably and has low energy consumption. The tubular membrane + chelating resin tower process can achieve deep hardness removal and organic matter removal. The overall operation and maintenance workload of the system is small, and the investment and operation are economical. It can avoid frequent chemical cleaning of the subsequent evaporator and is conducive to improving the quality of crystallized salt.

[0017] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0018] In addition, it should be noted that the above content described in this specification is only an example of the structure of the utility model. All equivalent changes made based on the structure, features and principles described in the utility model patent are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications, supplements or replace the specific embodiments described in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. A coal mine brine deep treatment process system, characterized in that: It comprises a high-salt wastewater tank (1), an antiscalant dosing device (3), a security filter (4), an energy recovery high-pressure pump (6), a STRO device (8), a STRO concentrated water tank (12), a STRO water production tank (13), a first reaction tank (15), a sodium carbonate dosing device (16), a sodium hydroxide dosing device (17), a flocculant dosing device (18), a powdered activated carbon dosing device (19), a second reaction tank (20), a concentration tank (21), a tubular membrane device (23), a polyacrylamide dosing device (25), a sludge dewatering machine (26), a tubular membrane water production tank (27), an acid adding device (28), a chelating resin tower (30) and an evaporator feed tank (31); The water outlet of the high-salinity wastewater pool (1) is connected to the water inlet of the security filter (4), the outlet of the antiscalant dosing device (3) is connected to the water inlet of the security filter (4), the water outlet of the security filter (4) is connected to the low-pressure water supply inlet of the energy recovery high-pressure pump (6) through a water delivery pipeline (5), the high-pressure water supply outlet of the energy recovery high-pressure pump (6) is connected to the water inlet of the STRO device (8) through a water inlet pipeline (7), the concentrated water outlet of the STRO device (8) is connected to the high-pressure concentrated water inlet of the energy recovery high-pressure pump (6) through a concentrated water pipeline (9), and the energy The low-pressure concentrated water outlet of the recovery high-pressure pump (6) is connected to the water inlet of the STRO concentrated water tank (12) through the low-pressure concentrated water pipeline (11), the water production outlet of the STRO device (8) is connected to the STRO water production tank (13), the water outlet of the STRO concentrated water tank (12) is connected to the water inlet of the first reaction tank (15), the drug outlets of the sodium carbonate dosing device (16) and the sodium hydroxide dosing device (17) are both connected to the drug inlet of the first reaction tank (15), the water outlet of the first reaction tank (15) is connected to the water inlet of the second reaction tank (20), and the flocculant dosing device The drug outlets of the acid adding device (18) and the powdered activated carbon dosing device (19) are both connected to the drug inlet of the second reaction tank (20), the water outlet of the second reaction tank (20) is connected to the water inlet of the concentration tank (21), the water outlet of the concentration tank (21) is connected to the water inlet of the tubular membrane device (23), the water production outlet of the tubular membrane device (23) is connected to the water inlet of the tubular membrane water production pool (27), the drug outlet of the acid adding device (28) is connected to the drug inlet of the tubular membrane water production pool (27), the water outlet of the tubular membrane water production pool (27) is connected to the water inlet of the chelating resin tower (30), The water outlet of the tubular membrane device (23) is connected to the water inlet of the concentration tank (21), the sludge discharge port of the concentration tank (21) is connected to the sludge inlet of the sludge dewatering machine (26), the drug outlet of the polyacrylamide dosing device (25) is connected to the sludge inlet of the sludge dewatering machine (26), the filtrate outlet of the sludge dewatering machine (26) is connected to the water inlet of the STRO concentrated water tank (12), the water outlet of the chelating resin tower (30) is connected to the water inlet of the evaporator feed tank (31), and the regenerated wastewater outlet of the chelating resin tower (30) is connected to the water inlet of the STRO concentrated water tank (12).

2. The coal mine brine deep treatment process system according to claim 1 is characterized in that: The water outlet of the high-salt wastewater pool (1) is connected to the water inlet of the security filter (4) through a first water supply pump (2); the concentrated water outlet of the STRO device (8) is connected to the water inlet of the first circulation pump (10) through a concentrated water pipeline (9), and the water outlet of the first circulation pump (10) is connected to the water inlet of the STRO device (8) through an inlet pipeline (7); the water outlet of the STRO concentrated water pool (12) is connected to the water inlet of the first reaction tank (15) through a second water supply pump (14); the water outlet of the concentration tank (21) is connected to the water inlet of the tubular membrane device (23) through a second circulation pump (22); the sludge outlet of the concentration tank (21) is connected to the sludge inlet of the sludge dewatering machine (26) through a sludge pump (24); the water outlet of the tubular membrane water production pool (27) is connected to the water inlet of the chelating resin tower (30) through a third water supply pump (29).

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