A coal mine underground coal slime water treatment reuse system and method

Abstract

The present invention relates to a coal mine underground coal slime water treatment reuse system and method, the system comprises a solid-liquid separation unit for removing large-size particles in coal slime water by vibration separation, cyclone separation and filtration, a pretreatment unit for removing suspended particles, flocs and colloids in coal slime water by precipitation, clarification and filtration, an ultrafiltration treatment unit for removing suspended particles, flocs and colloids in coal slime water by self-cleaning filtration and ultrafiltration membrane filtration, and a reverse osmosis treatment unit for reducing the content of soluble solids and ions in coal slime water by security filtration and reverse osmosis membrane filtration; the solid-liquid separation unit, pretreatment unit, ultrafiltration treatment unit and reverse osmosis treatment unit are connected in sequence by pipelines. The coal mine underground coal slime water treatment reuse system effectively reduces the difficulty of underground coal slime water treatment, avoids siltation in water tanks, reduces the energy consumption of lifting treatment, improves the efficiency of particle removal in coal slime water, and improves the underground reuse degree of mine water.

Description

Technical Field

[0001] The invention relates to a coal mine coal slime water treatment reuse system and method, in particular to a coal mine underground coal slime water treatment reuse system and method, belonging to the technical field of environmental protection. Background Art

[0002] my country's coal production capacity and number of coal mines rank first in the world, and the annual discharge of coal mine water and coal slurry water also ranks first in the world. Coal slurry water is formed by a mixture of mine water and impurities such as coal particles, coal powder, and rock powder, and mainly comes from underground working faces, tunnels, and goafs. The coal slurry water contains a high content of particulate matter and a variety of particle size distribution. It is very easy to deposit and clog during the confluence process from the underground working face to the water tank. Long-term siltation of coal slurry will increase the thickness of the coal slurry layer in the sedimentation tank and water tank, seriously reduce the water storage capacity of the water tank, and bring great challenges to underground anti-siltation and drainage, which in turn affects the normal production of the mine.

[0003] In conventional treatment methods, underground coal sludge water is directly lifted to the surface before being treated. During the underground transfer and lifting process, coal sludge water will be deposited in ditches, ditches and water tanks due to changes in flow rate. The deposited coal sludge mainly relies on manual cleaning. This traditional method has a low level of mechanization, high risk factor, high labor intensity and low cleaning efficiency. In addition, the conventional treatment of coal sludge water mainly focuses on removing particulate matter, and rarely considers reuse. Mine water that only removes particulate impurities such as coal particles, coal powder and rock powder is not conducive to deep reuse underground. At present, the conventional process used for coal sludge water treatment is "primary sedimentation-coagulation-sedimentation-filtration". The primary sedimentation method is to use the horizontal flow sedimentation tank transformed from the tunnel, but the precipitated coal sludge slag cannot be effectively removed, which increases the labor intensity of manual dredging. The amount of drug added during the coagulation process is large, the reaction time is long, and the treatment cost is high. The effluent quality after treatment by this conventional process is low, and it still contains organic matter, nitrogen and ammonia, emulsified oil, salts and other toxic and harmful ions, which limits the way and degree of treatment and reuse of coal sludge water.

[0004] In short, the reuse of coal slurry water first needs to solve the problem of coal slurry siltation. Secondly, advancing the surface coal slurry water treatment process to direct treatment underground can save a lot of energy consumption for lifting coal slurry water to the well, alleviate the wear of impurities such as particulate matter in the coal slurry water on pipelines and pump impellers, volutes and other components, and reduce pipeline blockage, system failure frequency and additional maintenance costs. Thirdly, direct deep treatment of coal slurry water underground and reuse of high-quality water can reduce the discharge of coal slurry water raised to the well, the investment in laying pipelines for underground reuse, and the risk of operation and management.

[0005] Therefore, inventing a system and method for directly treating and reusing coal slime water underground can not only save energy but also reduce underground siltation. At the same time, deep treatment of mine water underground can increase the degree of mine water reuse, which is of great significance to coal mine safety production and sustainable development. Summary of the invention

[0006] The purpose of the present invention is to provide a coal mine underground coal slime water treatment and reuse system, reduce the difficulty of underground coal slime water treatment, avoid water tank siltation, reduce the energy consumption of lifting treatment, improve the efficiency of particulate matter removal in coal slime water, improve the degree of underground mine water reuse, and solve the problems described in the background technology.

[0007] Another object of the present invention is to provide a method for treating and reusing coal slime water in underground coal mines.

[0008] The technical solution adopted by the present invention to solve the technical problem is:

[0009] A coal mine underground coal slime water treatment reuse system comprises a solid-liquid separation unit for removing large-size particles in the coal slime water by means of vibration separation, cyclone separation and filtration, a pretreatment unit for removing suspended particles, flocs and colloids in the coal slime water by means of precipitation, clarification and filtration, an ultrafiltration treatment unit for removing suspended particles, flocs and colloids in the coal slime water by means of self-cleaning filtration and ultrafiltration membrane filtration, and a reverse osmosis treatment unit for reducing the content of dissolved solids and ions in the coal slime water by means of security filtration and reverse osmosis membrane filtration; the solid-liquid separation unit, the pretreatment unit, the ultrafiltration treatment unit and the reverse osmosis treatment unit are connected in sequence by pipelines.

[0010] Preferably, the solid-liquid separation unit comprises a vibrating screen solid-liquid separation device, a high-precision cyclone separator, an ultra-precision cyclone separator, an ultra-precision filter screen device, a coal slime conveying belt, a collecting tank, an inlet pump, a primary buffer water tank and a secondary buffer water tank; the vibrating screen solid-liquid separation device and the ultra-precision filter screen device are both provided with a solid outlet and a liquid outlet, the solid outlet of the vibrating screen solid-liquid separation device and the solid outlet of the ultra-precision filter screen device are both connected to the coal slime conveying belt, the liquid outlet of the vibrating screen solid-liquid separation device is sequentially connected to the collecting tank and the high-precision cyclone separator, and the liquid outlet of the ultra-precision filter screen device is sequentially connected to the primary buffer water tank and the ultra-precision cyclone separator; the high-precision cyclone separator and the ultra-precision cyclone separator are both provided with a top overflow port and a bottom discharge port, the top overflow port of the high-precision cyclone separator and the top overflow port of the ultra-precision cyclone separator are both connected to the secondary buffer water tank, and the bottom discharge port of the high-precision cyclone separator and the bottom discharge port of the ultra-precision cyclone separator are both connected to the ultra-precision filter screen device.

[0011] Preferably, the vibrating screen solid-liquid separation device is provided with a first vibrator, a first vibrating screen, a first undersize collection bucket and a first collecting pipe in sequence from top to bottom, the first vibrating screen is set at an inclination, the outlet end of the first vibrating screen is located above the coal slime conveyor belt, and the first collecting pipe is connected to the collecting pool; the ultra-precision filtering screen device is provided with a second vibrator, a second vibrating screen, a second undersize collection bucket and a second collecting pipe in sequence from top to bottom, the second vibrating screen is set at an inclination, the outlet end of the second vibrating screen is located above the coal slime conveyor belt, and the second collecting pipe is connected to the primary buffer water tank.

[0012] Preferably, the vibration frequency of the first vibrating screen is 20-30 Hz, the screen hole diameter is 3.0-5.0 mm, the double amplitude is 2.0-3.0 mm, and the screen surface inclination is 5°-8°; the vibration frequency of the second vibrating screen is 30-35 Hz, the screen hole size is 0.5-1.0 mm, the double amplitude is 3.0-5.0 mm, and the screen surface inclination is 7°-9°.

[0013] Preferably, the pretreatment unit comprises a pre-sedimentation tank, a high-efficiency clarification tank, a mutual flushing filter and a coagulant dosing device, the pre-sedimentation tank, the high-efficiency clarification tank and the mutual flushing filter are connected in sequence through pipelines, and the coagulant dosing device is connected to the high-efficiency clarification tank.

[0014] Preferably, an aeration pipe and a plurality of inclined plates are provided in the upper part of the high-efficiency clarifier, a rotary scraper is provided in the lower part of the high-efficiency clarifier, and a traction motor is provided at the top of the high-efficiency clarifier; a horizontal traction rod movably connected to the inclined plate is provided at the top of the inclined plate, one end of the horizontal traction rod is elastically connected to the wall of the high-efficiency clarifier, and the other end of the horizontal traction rod is connected to the traction motor; a horizontal fixed rod movably connected to the inclined plate is provided at the bottom of the inclined plate, the horizontal fixed rod is fixedly connected to the wall of the high-efficiency clarifier, and the aeration pipe is provided below the horizontal fixed rod.

[0015] Preferably, the plurality of inclined plates are evenly distributed in parallel, the horizontal inclination angle of the inclined plates is 45° to 65°, the flippable angle range of the inclined plates is 50° to 90°, and the arrangement spacing of the inclined plates is 10 to 20 cm; the aeration pipe is provided with a plurality of aeration holes evenly distributed in annular shape, the aperture of the aeration holes is 5 to 10 mm, and the arrangement spacing of the aeration holes is 10 to 20 cm.

[0016] Preferably, the ultrafiltration treatment unit comprises a self-cleaning filter, an ultrafiltration device and a redox agent dosing device connected in sequence through pipelines, and the reverse osmosis treatment unit comprises a security filter, a reverse osmosis device and a scale inhibitor dosing device connected in sequence through pipelines.

[0017] A method for treating and reusing coal slime water in a coal mine using the above-mentioned coal slime water treatment and reuse system in a coal mine, the method specifically comprising the following steps:

[0018] S1. Make the coal slurry water in the coal mine enter the solid-liquid separation unit to remove the large particle size particles above 3.0 mm in the coal slurry water; this step is used to reduce the frequency of siltation in the underground water tank and the load of the subsequent processing unit;

[0019] S2. The coal slime water in step S1 enters a pretreatment unit, wherein the pretreatment unit includes a pre-sedimentation tank, a high-efficiency clarification tank, a mutual flushing filter and a coagulant dosing device. The pre-sedimentation tank, the high-efficiency clarification tank and the mutual flushing filter are sequentially connected through pipelines, and the coagulant dosing device is connected to the high-efficiency clarification tank, so that the coal slime water flows through the pre-sedimentation tank, the high-efficiency clarification tank and the mutual flushing filter in sequence, and 50-100 mg / L of polyaluminium chloride (PAC) and 0.5-1.0 mg / L of polyacrylamide (PAM) are added to the high-efficiency clarification tank through the coagulant dosing device, so that the suspended matter in the treated coal slime water is less than 20 mg / L; this step further removes suspended particles, flocs and some colloids in the coal slime water through gravity pre-sedimentation, clarification and filtration, respectively, so as to meet the water inlet requirements of subsequent steps;

[0020] S3. The coal slurry water in step S2 enters an ultrafiltration treatment unit, wherein the ultrafiltration treatment unit comprises a self-cleaning filter, an ultrafiltration device and an oxidation-reduction agent dosing device connected in sequence through pipelines, the coal slurry water flows through the self-cleaning filter and the ultrafiltration device in sequence, and sodium hypochlorite oxidant and sodium bisulfite reductant are added to the front of the self-cleaning filter through the oxidation-reduction agent dosing device; this step deeply removes suspended matter, flocs and colloids in the water through self-cleaning filtration and ultrafiltration respectively;

[0021] S4. The coal sludge water in step S3 enters a reverse osmosis treatment unit, which includes a security filter, a reverse osmosis device and a scale inhibitor dosing device connected in sequence through pipelines, so that the coal sludge water flows through the security filter and the reverse osmosis device in sequence, and the effluent is reused; this step further removes the soluble solids and ion content in the mine water through security filtration and reverse osmosis, respectively, to improve the effluent reuse water quality of the entire system.

[0022] Preferably, in step S1, the solid-liquid separation unit includes a vibrating screen solid-liquid separation device, a high-precision cyclone separator, an ultra-precision cyclone separator, an ultra-precision filter screen device, a coal slime conveying belt, a collecting tank, a water inlet pump, a primary buffer water tank and a secondary buffer water tank; the vibrating screen solid-liquid separation device is provided with a first vibrator, a first vibrating screen, a first undersize collection bucket and a first collecting pipe from top to bottom, the first vibrating screen is set at an inclination, the outlet end of the first vibrating screen is located above the coal slime conveying belt, and the first collecting pipe is connected to the collecting tank; the ultra-precision filter screen device is provided with a second vibrator, a second vibrating screen, a second undersize collection bucket and a second collecting pipe from top to bottom, the second vibrating screen is set at an inclination, the outlet end of the second vibrating screen is located above the coal slime conveying belt, and the second collecting pipe is connected to the primary buffer water tank; the specific steps of removing large particle size particles of 3.0 mm or more in coal slime water are as follows:

[0023] S11. Pump the coal slurry from underground coal mines into the vibrating screen solid-liquid separation device, so that the large-size particles and impurities on the first vibrating screen fall into the coal slurry conveyor belt with the vibration after the coal slurry is screened, and the particles and impurities under the screen flow into the first underscreen collection bucket with the coal slurry, and flow into the collection pool through the first collection pipe by gravity;

[0024] S12. Pump the coal slurry in the collection pool of step S11 into a high-precision cyclone separator, so that the coal slurry enters the high-precision cyclone separator in a tangential manner at an operating pressure of 0.2-0.3 MPa and a feed flow rate of 8.0-12.0 m / s. The bottom flow of the coal slurry concentrated by cyclone separation enters the ultra-precision filter screen device, and the overflow of the coal slurry enters the secondary buffer water tank;

[0025] S13. The coal slurry underflow is vibrated and filtered on the second vibrating screen. The particles on the screen with a small particle size of 1.0 mm or more fall into the coal slurry conveyor belt with the vibration and are transported away. The fine particles under the screen with a particle size of less than 1.0 mm and impurities flow into the second underscreen collection bucket and then flow into the primary buffer water tank through the second collection pipe;

[0026] S14. Pump the coal sludge water in the primary buffer water tank in step S13 into the ultra-precision cyclone separator, so that the coal sludge water enters the ultra-precision cyclone separator in a tangential manner at an operating pressure of 0.2-0.3MPa and a feed flow rate of 8.0-12.0m / s. The bottom flow of the coal sludge water concentrated by cyclone separation enters the ultra-precision filter screen device, and step S13 is repeated. The coal sludge water overflows into the secondary buffer water tank; the purpose of this step is to further concentrate the coal sludge and improve the screening efficiency to remove more than 80% of particulate matter.

[0027] The beneficial effects of the present invention are:

[0028] (1) The present invention performs underground treatment of coal slurry water, which can save the energy consumption cost and floor space of coal slurry water lifting compared with ground treatment, and can also avoid the impact of secondary pollutants in coal slurry water treatment on the ground environment;

[0029] (2) The present invention arranges the underground coal sludge water treatment system in front of the main drainage tank or the central water storage tank for treatment. Compared with the post-treatment in the water storage tank, most of the coal slag, coal sludge, rock powder and other sediments in the coal sludge water can be removed in advance, effectively preventing the siltation of ditches, canals and water storage tanks caused by the transfer of coal sludge water, reducing the intensity of dredging operations and the risk of underground water hazards;

[0030] (3) Compared with the existing traditional solid-liquid separation single technology, the solid-liquid separation unit of the present invention combines the principle of vibration screening with the principle of hydraulic cyclone separation. In view of the differences in particle size, density and viscosity of particles in coal slurry water, the solid-liquid separation technologies such as vibration screen, cyclone, filter screen and gravity concentration are coupled, and combined with automatic control technology to improve the targeted and broad-spectrum removal of particles of different particle sizes in coal slurry water;

[0031] (4) Compared with the existing coagulation sedimentation tank technology, the present invention adds an inclined plate component to the separation chamber of the clarification tank in the pretreatment unit, utilizes the shallow pool sedimentation principle to improve the mud-water separation effect, and designs an inclined plate mechanical turning mechanism and a bottom aeration device to prevent the deposition and clogging of high-concentration and high-viscosity coal sludge on the inclined plate after long-term operation;

[0032] (5) The existing underground treatment process of coal sludge water only achieves the purification and discharge process mainly for removing particulate matter, and rarely considers the reuse of mine water after coal sludge water treatment. The present invention expands the underground coal sludge water treatment process, adds ultrafiltration and reverse osmosis processes, and further deeply treats the purified mine water, thereby improving the water quality of mine water and expanding the depth and breadth of mine water reuse underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0035] Figure 2 It is a structural schematic diagram of the solid-liquid separation unit in the present invention;

[0036] Figure 3 It is a structural schematic diagram of a high-efficiency clarification tank in the present invention.

[0037] In the figure: 1, solid-liquid separation unit, 2, pretreatment unit, 3, ultrafiltration treatment unit, 4, reverse osmosis treatment unit, 11, vibrating screen solid-liquid separation device, 12, high-precision cyclone separator, 13, ultra-precision cyclone separator, 14, ultra-precision filter screen device, 15, coal slime conveyor belt, 21, pre-sedimentation tank, 22, high-efficiency clarification tank, 23, mutual flushing filter, 24, coagulant dosing device, 25, coal slime tank, 26, homogenization tank, 31, self-cleaning filter, 32, ultrafiltration membrane assembly device, 33, redox agent dosing device, 41, security filter, 42, reverse osmosis device, 43, scale inhibitor dosing device, 101, first vibrator, 102, first vibrating screen, 103, first undersize collection bucket, 104, first collection pipe, 105, collection tank, 106, water inlet Pump, 107, primary buffer water tank, 108, secondary buffer water tank, 141, second vibrator, 142, second vibrating screen, 143, second undersize collection bucket, 144, second collection pipe, 220, coagulation reaction chamber, 221, polyaluminium chloride (PAC) dosing pipe, 222, coagulation stirring paddle, 223, stirring motor, 230, flocculation reaction chamber, 231, polyacrylamide (PAM) dosing pipe, 232, flocculation stirring paddle, 240, diversion chamber, 250, mud-water separation chamber, 251, return spring, 252, horizontal traction rod, 253, inclined plate, 254, horizontal fixed rod, 255, aeration pipe, 256, traction motor, 257, traction steel rope, 258, fixed pulley, 259, rotary scraper, 2510, scraper plate, 2511, water collection weir. DETAILED DESCRIPTION

[0038] In order to alleviate the frequent siltation in underground water tanks of coal mines, the present invention changes the concept of coal slime water treatment from the traditional underground water tank collection and then lifting to the well treatment to direct treatment before the underground water tank, which can save the energy consumption cost of coal slime water lifting to the well treatment and avoid the frequent siltation in underground water tanks, wear of water pump pipeline equipment and other problems. At the same time, the present invention couples the vibration screening with the principle of hydraulic cyclone, and combines the inclined plate shallow pool sedimentation technology, targeting the differences in particle size, density and viscosity of particles in coal slime water, improves the pertinence and broad spectrum of the removal of particles of different particle sizes in coal slime water, and forms a coal mine underground coal slime water treatment reuse system and method by expanding the process flow of underground deep treatment of mine water.

[0039] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0040] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods.

[0041] Embodiment 1:

[0042] like Figure 1 The coal mine underground coal slime water treatment reuse system shown includes a solid-liquid separation unit 1 for removing large-size particles in the coal slime water by vibration separation, cyclone separation and filtration, a pretreatment unit 2 for removing suspended particles, flocs and colloids in the coal slime water by sedimentation, clarification and filtration, an ultrafiltration treatment unit 3 for removing suspended particles, flocs and colloids in the coal slime water by self-cleaning filtration and ultrafiltration membrane filtration, and a reverse osmosis treatment unit 4 for reducing the soluble solids and ion content in the coal slime water by security filtration and reverse osmosis membrane filtration; the solid-liquid separation unit 1, the pretreatment unit 2, the ultrafiltration treatment unit 3 and the reverse osmosis treatment unit 4 are connected in sequence by pipelines.

[0043] A method for treating and reusing coal slime water in a coal mine using the above-mentioned coal slime water treatment and reuse system in a coal mine, the method specifically comprising the following steps:

[0044] S1. Make the coal mine underground coal sludge water enter the solid-liquid separation unit 1, remove the coal sludge water with a large particle size of more than 3.0 mm, this step is used to reduce the frequency of underground water tank siltation and the load of subsequent processing units;

[0045] S2. The coal slime water in step S1 enters the pretreatment unit 2, wherein the pretreatment unit 2 comprises a pre-sedimentation tank 21, a high-efficiency clarification tank 22, a mutual flushing filter 23 and a coagulant dosing device 24. The pre-sedimentation tank 21, the high-efficiency clarification tank 22 and the mutual flushing filter 23 are sequentially connected through pipelines, and the coagulant dosing device 24 is connected to the high-efficiency clarification tank 22, so that the coal slime water flows through the pre-sedimentation tank 21, the high-efficiency clarification tank 22 and the mutual flushing filter 23 in sequence, and 50-100 mg / L of polyaluminium chloride (PAC) and 0.5-1.0 mg / L of polyacrylamide (PAM) are added into the high-efficiency clarification tank 22 through the coagulant dosing device 24, so that the suspended matter in the treated coal slime water is less than 20 mg / L. This step further removes suspended particles, flocs and some colloids in the coal slime water through gravity pre-sedimentation, clarification and filtration, respectively, so as to meet the water inlet requirements of subsequent steps;

[0046] S3. The coal slurry water in step S2 enters the ultrafiltration treatment unit 3, which includes a self-cleaning filter 31, an ultrafiltration device 32 and an oxidation-reduction agent dosing device 33 connected in sequence through pipelines, so that the coal slurry water flows through the self-cleaning filter 31 and the ultrafiltration device 32 in sequence, and sodium hypochlorite oxidant and sodium bisulfite reductant are added to the front of the self-cleaning filter 31 through the oxidation-reduction agent dosing device 33. This step deeply removes suspended matter, flocs and colloids in the water through self-cleaning filtration and ultrafiltration respectively;

[0047] S4. The coal sludge water in step S3 enters the reverse osmosis treatment unit 4, which includes a security filter 41, a reverse osmosis device 42 and a scale inhibitor dosing device 43 connected in sequence through pipelines. The coal sludge water flows through the security filter 41 and the reverse osmosis device 42 in sequence, and the effluent is reused. This step further removes the soluble solids and ion content in the mine water through security filtration and reverse osmosis, respectively, to improve the effluent reuse water quality of the entire system.

[0048] Embodiment 2:

[0049] like Figure 1 The coal mine underground coal slime water treatment reuse system shown includes a solid-liquid separation unit 1 for removing large-size particles in the coal slime water by vibration separation, cyclone separation and filtration, a pretreatment unit 2 for removing suspended particles, flocs and colloids in the coal slime water by sedimentation, clarification and filtration, an ultrafiltration treatment unit 3 for removing suspended particles, flocs and colloids in the coal slime water by self-cleaning filtration and ultrafiltration membrane filtration, and a reverse osmosis treatment unit 4 for reducing the soluble solids and ion content in the coal slime water by security filtration and reverse osmosis membrane filtration; the solid-liquid separation unit 1, the pretreatment unit 2, the ultrafiltration treatment unit 3 and the reverse osmosis treatment unit 4 are connected in sequence by pipelines.

[0050] like Figure 2 As shown, the solid-liquid separation unit 1 includes a vibrating screen solid-liquid separation device 11, a high-precision cyclone separator 12, an ultra-precision cyclone separator 13, an ultra-precision filter screen device 14, a coal slime conveyor belt 15, a collection tank 105, a water inlet pump 106, a primary buffer water tank 107 and a secondary buffer water tank 108.

[0051] The vibrating screen solid-liquid separation device 11 and the ultra-precision filter screen device 14 are both provided with a solid outlet and a liquid outlet. The solid outlet of the vibrating screen solid-liquid separation device 11 and the solid outlet of the ultra-precision filter screen device 14 are both connected to the coal slime conveyor belt 15. The liquid outlet of the vibrating screen solid-liquid separation device 11 is connected to the collection tank 105 and the high-precision cyclone separator 12 in sequence, and the liquid outlet of the ultra-precision filter screen device 14 is connected to the primary buffer water tank 107 and the ultra-precision cyclone separator 13 in sequence.

[0052] The high-precision cyclone separator 12 and the ultra-precision cyclone separator 13 are both provided with a top overflow port and a bottom discharge port. The top overflow port of the high-precision cyclone separator 12 and the top overflow port of the ultra-precision cyclone separator 13 are both connected to the secondary buffer water tank 108, and the bottom discharge port of the high-precision cyclone separator 12 and the bottom discharge port of the ultra-precision cyclone separator 13 are both connected to the ultra-precision filter screen device 14.

[0053] The vibrating screen solid-liquid separation device 11 is provided with a first vibrator 101, a first vibrating screen 102, a first undersize collection bucket 103 and a first collection pipe 104 from top to bottom. The first vibrating screen 102 is arranged at an inclined angle. The outlet end of the first vibrating screen 102 is located above the coal slime conveying belt 15. The first collection pipe 104 is connected to the collection tank 105.

[0054] The ultra-precision filtering screen device 14 is provided with a second vibrator 141, a second vibrating screen 142, a second undersize collection bucket 143 and a second collecting pipe 144 in sequence from top to bottom. The second vibrating screen 142 is arranged at an inclined angle. The outlet end of the second vibrating screen 142 is located above the coal slime conveying belt 15. The second collecting pipe 144 is connected to the primary buffer water tank 107.

[0055] The vibration frequency of the first vibrating screen 102 is 20-30 Hz, the mesh diameter is 3.0-5.0 mm, the double amplitude is 2.0-3.0 mm, and the screen surface inclination is 5°-8°. In this embodiment, the vibration frequency of the first vibrating screen 102 is 24 Hz, the mesh diameter is 3.0 mm, the double amplitude is 2.0 mm, and the screen surface inclination is 6°.

[0056] The vibration frequency of the second vibrating screen 142 is 30-35 Hz, the mesh size is 0.5-1.0 mm, the double amplitude is 3.0-5.0 mm, and the screen surface inclination is 7°-9°. In this embodiment, the vibration frequency of the second vibrating screen 142 is 30 Hz, the mesh diameter is 1.0 mm, the double amplitude is 3.0 mm, and the screen surface inclination is 8°.

[0057] The separation accuracy of the high-precision cyclone separator 12 is 1.0-2.0 mm, and the separation accuracy of the ultra-precision cyclone separator 13 is 0.5-1.0 mm. The cyclone separator operation mode adopts two parallel operation modes with different precisons.

[0058] The pretreatment unit 2 includes a pre-sedimentation tank 21, a high-efficiency clarification tank 22, a mutual flushing filter 23 and a coagulant dosing device 24. The pre-sedimentation tank 21, the high-efficiency clarification tank 22 and the mutual flushing filter 23 are connected in sequence through pipelines. The coagulant dosing device 24 is connected to the high-efficiency clarification tank 22. The bottom of the pre-sedimentation tank 21 is connected to a coal slime tank 25, and the bottom of the high-efficiency clarification tank 22 is connected to a homogenization tank 26.

[0059] A horizontal flow sedimentation tank and a water absorption tank are sequentially arranged in the pre-sedimentation tank 21. A square cone mud bucket is arranged at the bottom of the horizontal flow sedimentation tank to discharge the tiny coal slime particles separated by gravity sedimentation in time. An aeration device is arranged at the bottom of the water absorption tank to prevent coal slime siltation in the water absorption tank through aeration at the bottom of the tank.

[0060] like Figure 3 As shown, the high-efficiency clarification tank 22 is provided with a coagulation reaction chamber 220, a flocculation reaction chamber 230, a flow guide chamber 240 and a mud-water separation chamber 250 in sequence.

[0061] A coagulation stirring paddle 222 is provided in the coagulation reaction chamber 220 , and the top of the coagulation stirring paddle 222 is connected to a stirring motor 223 extending from the top of the high-efficiency clarification tank 22 . The top of the coagulation reaction chamber 220 is connected to a polyaluminium chloride (PAC) dosing pipe 221 .

[0062] A flocculation stirring paddle 232 is provided in the flocculation reaction chamber 230 . The top of the flocculation stirring paddle 232 is connected to a stirring motor 223 extending from the top of the high-efficiency clarification tank 22 . The top of the flocculation reaction chamber 230 is connected to a polyacrylamide (PAM) dosing pipe 231 .

[0063] An aeration pipe 255 and a plurality of inclined plates 253 are provided at the upper inner part of the mud-water separation chamber 250. A rotary scraper 259 is provided at the inner part of the mud-water separation chamber 250. The top of the rotary scraper 259 is connected to a stirring motor 223 extending from the top of the high-efficiency clarification tank 22. A scraper plate 2510 is provided at the bottom of the rotary scraper 259. A traction motor 256 is provided at the top of the high-efficiency clarification tank 22. A water collecting weir 2511 is also provided at the upper inner part of the mud-water separation chamber 250.

[0064] A horizontal traction rod 252 movably connected to the inclined plate 253 is provided at the top of the inclined plate 253. One end of the horizontal traction rod 252 is elastically connected to the wall of the high-efficiency clarification tank 22 through a return spring 251, and the other end of the horizontal traction rod 252 is connected to the traction motor 256 through a traction wire 257 on a fixed pulley 258.

[0065] A horizontal fixing rod 254 movably connected to the inclined plate 253 is provided at the bottom of the inclined plate 253 . The horizontal fixing rod 254 is fixedly connected to the wall of the high-efficiency clarification tank 22 . The aeration pipe 255 is provided below the horizontal fixing rod 254 .

[0066] The plurality of inclined plates 253 are evenly distributed in parallel, the horizontal inclination angle of the inclined plates 253 is 45° to 65°, the tiltable angle range of the inclined plates 253 is 50° to 90°, and the arrangement spacing of the inclined plates 253 is 10 to 20 cm. In this embodiment, the inclined plates 253 are installed at an inclination angle of 60°, the tiltable angle is 60°, and the installation spacing of the inclined plates 253 is 15 cm.

[0067] The aeration tube 255 is provided with a plurality of aeration holes evenly distributed in an annular shape, the diameter of the aeration holes is 5-10 mm, and the spacing of the aeration holes is 10-20 cm. In this embodiment, the diameter of the aeration holes evenly spaced in an annular shape on the aeration tube is 8 mm, and the spacing of the holes is 15 cm.

[0068] The mutual flushing filter 23 is operated in parallel filtration and air-water backwashing mode. In filtering mode, all filters filter at the same time; in backwashing mode, the backwashing water of one filter is provided by the filtered water produced by the other filters, and there is no need to set up an additional backwashing water tank to provide backwashing water.

[0069] The ultrafiltration treatment unit 3 comprises a self-cleaning filter 31, an ultrafiltration device 32 and an oxidation-reduction agent dosing device 33 which are sequentially connected by pipelines. The self-cleaning filter 31 is mainly used to further reduce the impurities in the water entering the ultrafiltration device 32, and realizes automatic cleaning by pressure difference control.

[0070] The reverse osmosis treatment unit 4 includes a security filter 41, a reverse osmosis device 42 and an antiscalant dosing device 43 which are sequentially connected through pipelines.

[0071] A method for treating and reusing coal slime water in a coal mine using the above-mentioned coal slime water treatment and reuse system in a coal mine, the method specifically comprising the following steps:

[0072] S1. Make the coal mine underground coal sludge water enter the solid-liquid separation unit 1, remove the coal sludge water with a large particle size of more than 3.0 mm, this step is used to reduce the frequency of underground water tank siltation and the load of subsequent processing units;

[0073] S2. The coal slime water in step S1 enters the pretreatment unit 2, wherein the pretreatment unit 2 comprises a pre-sedimentation tank 21, a high-efficiency clarification tank 22, a mutual flushing filter 23 and a coagulant dosing device 24. The pre-sedimentation tank 21, the high-efficiency clarification tank 22 and the mutual flushing filter 23 are sequentially connected through pipelines, and the coagulant dosing device 24 is connected to the high-efficiency clarification tank 22, so that the coal slime water flows through the pre-sedimentation tank 21, the high-efficiency clarification tank 22 and the mutual flushing filter 23 in sequence, and 50-100 mg / L of polyaluminium chloride (PAC) and 0.5-1.0 mg / L of polyacrylamide (PAM) are added into the high-efficiency clarification tank 22 through the coagulant dosing device 24, so that the suspended matter in the treated coal slime water is less than 20 mg / L. This step further removes suspended particles, flocs and some colloids in the coal slime water through gravity pre-sedimentation, clarification and filtration, respectively, so as to meet the water inlet requirements of subsequent steps;

[0074] S3. The coal slurry water in step S2 enters the ultrafiltration treatment unit 3, which includes a self-cleaning filter 31, an ultrafiltration device 32 and an oxidation-reduction agent dosing device 33 connected in sequence through pipelines, so that the coal slurry water flows through the self-cleaning filter 31 and the ultrafiltration device 32 in sequence, and sodium hypochlorite oxidant and sodium bisulfite reductant are added to the front of the self-cleaning filter 31 through the oxidation-reduction agent dosing device 33. This step deeply removes suspended matter, flocs and colloids in the water through self-cleaning filtration and ultrafiltration respectively;

[0075] S4. The coal sludge water in step S3 enters the reverse osmosis treatment unit 4, which includes a security filter 41, a reverse osmosis device 42 and a scale inhibitor dosing device 43 connected in sequence through pipelines. The coal sludge water flows through the security filter 41 and the reverse osmosis device 42 in sequence, and the effluent is reused. This step further removes the soluble solids and ion content in the mine water through security filtration and reverse osmosis, respectively, to improve the effluent reuse water quality of the entire system.

[0076] In the above step S1, the specific steps of removing particles with a diameter of more than 3.0 mm in the coal slurry water are as follows:

[0077] S11. Pump the coal slurry from underground coal mine into the vibrating screen solid-liquid separation device 11, so that the large-size particles and impurities on the first vibrating screen 102 after the coal slurry is screened fall into the coal slurry conveyor belt 15 with the vibration and are transported away, and the particles and impurities under the screen flow into the first underscreen collection bucket 103 with the coal slurry, and flow into the collection pool 105 by gravity through the first collection pipe 104;

[0078] S12. Pump the coal slurry in the collection tank 105 in step S11 into the high-precision cyclone separator 12, so that the coal slurry enters the high-precision cyclone separator 12 in a tangential manner at an operating pressure of 0.2-0.3 MPa and a feed flow rate of 8.0-12.0 m / s. The bottom flow of the coal slurry concentrated by cyclone separation enters the ultra-precision filter screen device 14, and the overflow of the coal slurry enters the secondary buffer water tank 108;

[0079] S13. The coal slurry underflow is vibrated and filtered on the second vibrating screen 142. The particles with a small particle size of 1.0 mm or more fall into the coal slurry conveyor belt 15 with the vibration and are transported away. The fine particle size of 1.0 mm or less and impurities flow into the second undersize collection bucket 143, and then flow into the primary buffer water tank 107 through the second collection pipe 144;

[0080] S14. Pump the coal sludge water in the primary buffer water tank 107 of step S13 into the ultra-precision cyclone separator 13, so that the coal sludge water enters the ultra-precision cyclone separator 13 in a tangential manner at an operating pressure of 0.2-0.3 MPa and a feed flow rate of 8.0-12.0 m / s. The bottom flow of the coal sludge water after cyclone separation and concentration enters the ultra-precision filter screen device 14, and step S13 is repeated. The coal sludge water overflows into the secondary buffer water tank 108. The purpose of this step is to further concentrate the coal sludge and improve the screening efficiency to remove more than 80% of particulate matter.

[0081] In the above step S2, the silted coal slime on the inclined plate 253 in the high-efficiency clarifier 22 is removed by mechanical flipping and aeration disturbance. Under the traction of the traction motor 256, the inclined plate 253 drives the horizontal traction rod 252 to move horizontally through the traction wire 257, forcing the inclined plate 253 to rotate as a whole around the fulcrum on the bottom horizontal fixed rod 254, and at the same time stretching the reset spring 251 on the other end of the horizontal traction rod 252; conversely, after the traction motor 256 cancels the traction of the traction wire 257, the horizontal traction rod 252 forces the inclined plate 253 to rotate in the opposite direction around the fulcrum on the bottom horizontal fixed rod 254 and resets it, completing a flipping and silting work cycle of the inclined plate. At the same time, the bubbles generated by the aeration pipe 255 can collide and disturb the coal slime attached to the inclined plate 253, thereby enhancing the mud removal effect.

[0082] Based on the above-mentioned method for treating and reusing coal slime water in coal mines, the effluent quality of each treatment unit is listed in Table 1. The effluent of each treatment unit in the system can be reused in underground dust prevention and sprinkling, equipment cooling, emulsion preparation and other reuse paths and directions according to the water quality, thereby improving the reuse rate of mine water in the mine and reducing the discharge of mine water and coal slime from the mine.

[0083] Table 1 Water quality of effluent from each treatment unit of the coal slime water treatment reuse system

[0084]

[0085]

[0086] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A coal mine underground coal slime water treatment and reuse system, characterized by: The coal mine underground coal slime water treatment reuse system comprises a solid-liquid separation unit (1) for removing large-size particles in the coal slime water by means of vibration separation, cyclone separation and filtration, a pretreatment unit (2) for removing suspended particles, flocs and colloids in the coal slime water by means of precipitation, clarification and filtration, an ultrafiltration treatment unit (3) for removing suspended particles, flocs and colloids in the coal slime water by means of self-cleaning filtration and ultrafiltration membrane filtration, and a reverse osmosis treatment unit (4) for reducing the content of dissolved solids and ions in the coal slime water by means of security filtration and reverse osmosis membrane filtration; the solid-liquid separation unit (1), the pretreatment unit (2), the ultrafiltration treatment unit (3) and the reverse osmosis treatment unit (4) are connected in sequence by pipelines; The solid-liquid separation unit (1) comprises a vibrating screen solid-liquid separation device (11), a high-precision cyclone separator (12), an ultra-precision cyclone separator (13), an ultra-precision filter screen device (14), a coal slime conveying belt (15), a collection tank (105), a water inlet pump (106), a primary buffer water tank (107), and a secondary buffer water tank (108); the vibrating screen solid-liquid separation device (11) and the ultra-precision filter screen device (14) are both provided with a solid outlet and a liquid outlet; the solid outlet of the vibrating screen solid-liquid separation device (11) and the solid outlet of the ultra-precision filter screen device (14) are both connected to the coal slime conveying belt (15); the vibrating screen solid-liquid separation device (11) The liquid outlet of the high-precision cyclone separator (105) is connected to the collection tank (105) and the high-precision cyclone separator (12) in sequence, and the liquid outlet of the ultra-precision filter screen device (14) is connected to the primary buffer water tank (107) and the ultra-precision cyclone separator (13) in sequence; the high-precision cyclone separator (12) and the ultra-precision cyclone separator (13) are both provided with a top overflow port and a bottom discharge port, the top overflow port of the high-precision cyclone separator (12) and the top overflow port of the ultra-precision cyclone separator (13) are both connected to the secondary buffer water tank (108), and the bottom discharge port of the high-precision cyclone separator (12) and the bottom discharge port of the ultra-precision cyclone separator (13) are both connected to the ultra-precision filter screen device (14); The pretreatment unit (2) comprises a pre-sedimentation tank (21), a high-efficiency clarification tank (22), a mutual flushing filter (23) and a coagulant dosing device (24); the pre-sedimentation tank (21), the high-efficiency clarification tank (22) and the mutual flushing filter (23) are connected in sequence via pipelines, and the coagulant dosing device (24) is connected to the high-efficiency clarification tank (22); An aeration pipe (255) and a plurality of inclined plates (253) are provided at the upper part of the high-efficiency clarifier (22); a rotary sludge scraper (259) is provided at the lower part of the high-efficiency clarifier (22); and a traction motor (256) is provided at the top of the high-efficiency clarifier (22); a horizontal traction rod (252) movably connected to the inclined plate (253) is provided at the top of the inclined plate (253); one end of the horizontal traction rod (252) is elastically connected to the wall of the high-efficiency clarifier (22); and the other end of the horizontal traction rod (252) is connected to the traction motor (256); a horizontal fixing rod (254) movably connected to the inclined plate (253) is provided at the bottom of the inclined plate (253); the horizontal fixing rod (254) is fixedly connected to the wall of the high-efficiency clarifier (22); and the aeration pipe (255) is provided below the horizontal fixing rod (254); The plurality of inclined plates (253) are evenly distributed in parallel, the horizontal inclination angle of the inclined plates (253) is 45° to 65°, the tiltable angle range of the inclined plates (253) is 50° to 90°, and the arrangement spacing of the inclined plates (253) is 10 to 20 cm; the aeration pipe (255) is provided with a plurality of aeration holes evenly distributed in an annular shape, the aperture of the aeration holes is 5 to 10 mm, and the arrangement spacing of the aeration holes is 10 to 20 cm.

2. A coal mine underground coal slime water treatment and reuse system according to claim 1, characterized in that: The vibrating screen solid-liquid separation device (11) is provided with a first vibrator (101), a first vibrating screen (102), a first undersize collection bucket (103) and a first collection pipe (104) in order from top to bottom; the first vibrating screen (102) is arranged at an angle; the outlet end of the first vibrating screen (102) is located above the coal slime conveying belt (15); and the first collection pipe (104) is connected to a collection tank (105); the ultra-precision filtering screen device (14) is provided with a second vibrator (141), a second vibrating screen (142), a second undersize collection bucket (143) and a second collection pipe (144) in order from top to bottom; the second vibrating screen (142) is arranged at an angle; the outlet end of the second vibrating screen (142) is located above the coal slime conveying belt (15); and the second collection pipe (144) is connected to a primary buffer water tank (107).

3. A coal mine underground coal slime water treatment and reuse system according to claim 2, characterized in that: The first vibrating screen (102) has a vibration frequency of 20-30 Hz, a screen hole diameter of 3.0-5.0 mm, a double amplitude of 2.0-3.0 mm, and a screen surface inclination of 5°-8°; the second vibrating screen (142) has a vibration frequency of 30-35 Hz, a screen hole size of 0.5-1.0 mm, a double amplitude of 3.0-5.0 mm, and a screen surface inclination of 7°-9°.

4. A coal mine underground coal slime water treatment and reuse system according to claim 1, characterized in that: The ultrafiltration treatment unit (3) comprises a self-cleaning filter (31), an ultrafiltration device (32) and an oxidation-reduction agent dosing device (33) which are sequentially connected via pipelines, and the reverse osmosis treatment unit (4) comprises a security filter (41), a reverse osmosis device (42) and an antiscalant dosing device (43) which are sequentially connected via pipelines.

5. A method for treating and reusing coal slime water in a coal mine using a coal mine underground coal slime water treatment and reuse system according to any one of claims 1 to 4, characterized in that: The method specifically comprises the following steps: S1. The coal slurry water from the coal mine enters the solid-liquid separation unit (1) to remove particles larger than 3.0 mm in diameter from the coal slurry water; S2. The coal slurry water in step S1 enters a pretreatment unit (2), wherein the pretreatment unit (2) comprises a pre-sedimentation tank (21), a high-efficiency clarification tank (22), a mutual flushing filter (23) and a coagulant dosing device (24), wherein the pre-sedimentation tank (21), the high-efficiency clarification tank (22) and the mutual flushing filter (23) are sequentially connected through pipelines, and the coagulant dosing device (24) is connected to the high-efficiency clarification tank (22), so that the coal slurry water flows through the pre-sedimentation tank (21), the high-efficiency clarification tank (22) and the mutual flushing filter (23) in sequence, and 50-100 mg / L of polyaluminium chloride (PAC) and 0.5-1.0 mg / L of polyacrylamide (PAM) are added into the high-efficiency clarification tank (22) through the coagulant dosing device (24), so that the suspended solids in the treated coal slurry water are less than 20 mg / L; S3. allowing the coal slurry water in step S2 to enter an ultrafiltration treatment unit (3), wherein the ultrafiltration treatment unit (3) comprises a self-cleaning filter (31), an ultrafiltration device (32), and an oxidation-reduction agent dosing device (33) which are sequentially connected via a pipeline, allowing the coal slurry water to flow through the self-cleaning filter (31) and the ultrafiltration device (32) in sequence, and adding sodium hypochlorite oxidizing agent and sodium bisulfite reducing agent to the front of the self-cleaning filter (31) via the oxidation-reduction agent dosing device (33); S4. The coal slurry water in step S3 enters a reverse osmosis treatment unit (4), wherein the reverse osmosis treatment unit (4) comprises a security filter (41), a reverse osmosis device (42) and a scale inhibitor dosing device (43) connected in sequence through a pipeline, and the coal slurry water flows through the security filter (41) and the reverse osmosis device (42) in sequence, and the effluent is reused; In step S1, the solid-liquid separation unit (1) comprises a vibrating screen solid-liquid separation device (11), a high-precision cyclone separator (12), an ultra-precision cyclone separator (13), an ultra-precision filter screen device (14), a coal slime conveying belt (15), a collection tank (105), a water inlet pump (106), a primary buffer water tank (107) and a secondary buffer water tank (108); the vibrating screen solid-liquid separation device (11) is provided with a first vibrator (101), a first vibrating screen (102), a first undersize collection bucket (103) and a first collection pipe (104) in order from top to bottom; the first vibrating screen (102) is arranged at an inclination angle; the first The outlet end of the vibrating screen (102) is located above the coal slime conveying belt (15), and the first collecting pipe (104) is connected to the collecting pool (105); the ultra-precision filtering screen device (14) is provided with a second vibrator (141), a second vibrating screen (142), a second undersize collection bucket (143) and a second collecting pipe (144) in order from top to bottom; the second vibrating screen (142) is arranged at an inclined angle, the outlet end of the second vibrating screen (142) is located above the coal slime conveying belt (15), and the second collecting pipe (144) is connected to a primary buffer water tank (107); the specific steps of removing large particle size particles larger than 3.0 mm in coal slime water are as follows: S11. Pumping coal slurry from underground coal mines into a vibrating screen solid-liquid separation device (11), so that the large-size particles and impurities on the sieve after being screened by the first vibrating screen (102) fall into the coal slurry conveyor belt (15) with vibration and are transported away, and the particles and impurities under the sieve flow into the first under-sieve collection bucket (103) along with the coal slurry, and flow into the collection pool (105) by gravity through the first collection pipe (104); S12. The coal slurry in the collection tank (105) of step S11 is pumped into the high-precision cyclone separator (12), so that the coal slurry enters the high-precision cyclone separator (12) in a tangential manner at an operating pressure of 0.2-0.3 MPa and a feed flow rate of 8.0-12.0 m / s. The bottom flow of the coal slurry concentrated by cyclone separation enters the ultra-precision filter screen device (14), and the overflow of the coal slurry enters the secondary buffer water tank (108); S13. The coal slurry bottom flow is vibrated and filtered on the second vibrating screen (142), and particles on the screen with a small particle size of 1.0 mm or more fall into the coal slurry conveyor belt (15) with the vibration and are transported away, and particles under the screen with a fine particle size of less than 1.0 mm and impurities flow into the second underscreen collection bucket (143), and then flow into the primary buffer water tank (107) through the second collection pipe (144); S14. The coal slurry water in the primary buffer water tank (107) of step S13 is pumped into the ultra-precision cyclone separator (13), so that the coal slurry water enters the ultra-precision cyclone separator (13) in a tangential manner at an operating pressure of 0.2-0.3 MPa and a feed flow rate of 8.0-12.0 m / s. The bottom flow of the coal slurry water after cyclone separation and concentration enters the ultra-precision filter screen device (14), and step S13 is repeated. The coal slurry water overflows and enters the secondary buffer water tank (108).

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