Coal-containing wastewater treatment device and coal-containing wastewater treatment method

Abstract

This invention discloses a coal-containing wastewater treatment device and method, relating to the field of coal-containing wastewater treatment technology. The device includes: a coal-water sedimentation tank, a microcrystalline filter tank, an intermediate water tank, a microcrystalline filter, and a coal-water reuse tank. The coal-water sedimentation tank is connected to the microcrystalline filter tank via an upper port, and the microcrystalline filter tank is connected to the intermediate water tank via a lower port. The microcrystalline filter tank contains a filter element assembly located between the upper and lower ports, with the upper port higher than the lower port. The microcrystalline filter is pumped into the intermediate water tank via a coal-water inlet pipe, which is a coal-water lift pump. The microcrystalline filter is connected to the reuse tank via a guide pipe and an outlet pipe. This invention achieves the technical effect of filtration using the filter element assembly.

Description

Technical Field

[0001] This invention relates to the field of coal-containing wastewater treatment technology, and more specifically to a coal-containing wastewater treatment device and a coal-containing wastewater treatment method. Background Technology

[0002] Coal slurry is coal-containing wastewater formed when coal comes into contact with water during mining, washing, transportation, and storage. Coal slurry contains coal dust, suspended solids, heavy metals (such as mercury and lead), and chemical agents (such as flocculants). Direct discharge of coal slurry will damage the aquatic ecosystem, leading to eutrophication or toxic accumulation in water bodies.

[0003] Traditional coal-containing wastewater treatment mainly employs a "coagulation and clarification + filtration" process. However, this process suffers from problems such as complex structure, poor operating conditions, unsatisfactory treatment effect, high reagent consumption, and high operation and maintenance costs. While the "electro-flocculation + multi-media filtration" process, promoted in recent years, eliminates the need for reagents and produces better effluent quality, it suffers from high power consumption, unstable operation, electrode passivation and polarization (requiring replacement every 1-2 years), high failure rate, and high operation and maintenance costs. Filter elements, as a novel filter material, can efficiently trap micron-sized particles through the synergistic effect of mechanical sieving and adsorption. Furthermore, material modification (such as ceramic-based or metal-based) enhances corrosion resistance, making it a key technology for solving the bottleneck in coal-containing wastewater treatment. Microcrystalline filters filled with microcrystalline filter media achieve efficient trapping of suspended solids through deep adsorption and trapping, enabling particles to be efficiently trapped under inertial collision, diffusion, and van der Waals force adsorption. Ultimately, the suspended solids concentration (SS) is ≤10 mg / L. Because of the deterministic pore size of the microcrystalline filter media (filter elements and microcrystalline filter media), even if the influent water volume and water quality fluctuate, it will not affect the stability of the effluent water volume and water quality. Therefore, the system has strong resistance to load shocks.

[0004] Therefore, how to provide a coal-containing wastewater treatment device and method that utilizes filter elements for filtration is one of the technical problems that urgently need to be solved in this field. Summary of the Invention

[0005] In view of the above, the present invention provides a coal-containing wastewater treatment device and a coal-containing wastewater treatment method. The purpose of this invention is to address the aforementioned shortcomings.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A coal-containing wastewater treatment device includes: a coal-water sedimentation tank, a microcrystalline filter tank, an intermediate water tank, a microcrystalline filter, and a coal-water reuse tank; the coal-water sedimentation tank is connected to the microcrystalline filter tank through an upper port, the microcrystalline filter tank is connected to the intermediate water tank through a lower port, the microcrystalline filter tank is provided with a filter element group, the filter element group is located between the upper port and the lower port, and the upper port is higher than the lower port; the microcrystalline filter is pumped to the intermediate water tank through a coal-water backwash inlet pipe; the microcrystalline filter is connected to the reuse tank through a guide pipe.

[0007] Preferably, the coal-water sedimentation tank is connected to a coal-containing wastewater pipeline in the plant area on one side of the microcrystalline filter tank.

[0008] Preferably, the microcrystalline filter tank is divided into an ash accumulation zone and a filtration zone; the ash accumulation zone is adjacent to the upper port, and the coal-water sedimentation tank is connected to the ash accumulation zone through the upper port; the filtration zone is adjacent to the lower port, and the filtration zone is connected to the intermediate water tank through the lower port; the filter element group is disposed inside the filtration zone.

[0009] Preferably, the upper port is located near the top of the ash accumulation area; the lower port is located near the bottom of the filtration area.

[0010] Preferably, the bottom of the ash accumulation zone is lower than the bottom of the filtration zone.

[0011] Preferably, the filter element group includes one or more filter elements; the plurality of filter elements are arranged longitudinally, and each filter element is vertically bonded to each other; each filter element is made of alumina, silicon carbide, microcrystalline ceramic particle aggregate, mixed with binder, pore-forming agent and corrosion inhibitor, and is formed by pressing and high-temperature sintering.

[0012] Preferably, the microcrystalline filter comprises: a housing and filter media, wherein the filter media is filled inside the housing.

[0013] Preferably, it further includes an outlet pipe and a backwash inlet pipe; one end of the guide pipe is connected to the outer shell, and the other end of the guide pipe is connected to the outlet pipe and the backwash inlet pipe respectively through a tee; the end of the outlet pipe away from the guide pipe extends into the coal-water reuse tank; the end of the backwash inlet pipe away from the guide pipe extends into the coal-water reuse tank.

[0014] A method for treating coal-containing wastewater includes the following steps: S1. Coal slurry flows into the coal slurry sedimentation tank through the coal-containing wastewater pipeline in the plant area; S2, Coal molten material overflows into the ash accumulation area; S3. Coal-fired water flows by gravity from the ash accumulation area to the filtration area; S4. Coal sludge in the molten coal settles to the bottom of the ash accumulation zone and the filtration zone; S5. Coal-fired water flows through the filter element to the clean water zone at the bottom of the filtration area; S6. The coal water at the bottom of the filtration zone flows into the intermediate water tank; S7. The coal water in the intermediate water tank is pumped into the microcrystalline filter through the inlet pipe. S8. The coal water is treated by the microcrystalline filter and flows sequentially through the guide pipe and the outlet pipe to the coal water reuse tank. S9. When the microcrystalline filter needs to be rinsed, start the backwash pump in the backwash inlet pipe. Clean water will backwash the microcrystalline filter through the backwash inlet pipe and the guide pipe.

[0015] The present invention achieves the following technical effects compared to the prior art: The coal-water sedimentation tank is connected to the microcrystalline filter tank through its upper port, and the microcrystalline filter tank is connected to the intermediate water tank through its lower port. The microcrystalline filter tank is equipped with a filter element group, which is located between the upper port and the lower port, with the upper port being higher than the lower port. The microcrystalline filter is connected to the intermediate water tank pump through an inlet pipe, and the microcrystalline filter is connected to the reclaimed water tank through a guide pipe, thereby achieving the technical effect of filtration using the filter element group. The microcrystalline filter tank is divided into an ash collection zone and a filtration zone. The ash collection zone is used to collect coal sludge from the coal slurry. The bottom of the ash collection zone is lower than the bottom of the filtration zone to facilitate the collection of coal sludge. The filter element group includes one or more filter elements; multiple filter elements are arranged longitudinally, and each filter element is vertically bonded to each other; each filter element is made of alumina, silicon carbide, microcrystalline ceramic particles, mixed with binder, pore-forming agent, and corrosion inhibitor, and is formed into a column or strip shape by pressing and high-temperature sintering. It has micron-sized pores, a diatomaceous earth hard shell and coconut shell fiber, and the diatomaceous earth hard shell wraps the coconut shell fiber for filtration and adsorption. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of Embodiment 1 of the present invention; Figure 2 This is another schematic diagram of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the filter element assembly and the clear water tank of the present invention. Figure 4 This is a schematic diagram of the longitudinal bonding connection of the filter element of the present invention; Figure 5 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; In the picture: 1-Coal-water sedimentation tank; 2-Microcrystalline filter tank; 21-Filter element group; 23-Dust accumulation area; 24-Filtration area; 25-Clear water tank; 3-Intermediate water tank; 4-Microcrystalline filter; 5-Coal-water reuse pool; 6-Upper port; 7-Lower Port; 8-Inlet pipe; 9-Guide pipe; 91-Outlet pipe; 92-Backwash inlet pipe; 10- Backwash slag discharge pipe; 11-Coal-containing wastewater pipeline in the factory area; 12-Coal conveying and washing system; 13-Spare tube. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 Reference Figure 1-4 The device for treating coal-containing wastewater includes: a coal-water sedimentation tank 1, a microcrystalline filter tank 2, an intermediate water tank 3, a microcrystalline filter 4, and a coal-water reuse tank 5. The coal-water sedimentation tank 1 is connected to the microcrystalline filter tank 2 via an upper port 6. The side of the coal-water sedimentation tank 1 furthest from the microcrystalline filter tank 2 is connected to a coal-containing wastewater pipeline 11 within the plant area. The microcrystalline filter tank 2 is connected to the intermediate water tank 3 via a lower port 7. A filter element assembly 21 is installed within the microcrystalline filter tank 2, located between the upper port 6 and the lower port 7, with the upper port 6 higher than the lower port 7 to facilitate the flow of coal-water.

[0019] The microcrystalline filter tank 2 is divided into an ash accumulation zone 23 and a filtration zone 24. The ash accumulation zone 23 is adjacent to the upper port 6, and the coal-water sedimentation tank 1 is connected to the ash accumulation zone 23 through the upper port 6. The filtration zone 24 is adjacent to the lower port 7, and the filtration zone 24 is connected to the intermediate water tank 3 through the lower port 7. The filter element group 21 is set inside the filtration zone 24.

[0020] like Figure 3 As shown, multiple filter elements are arranged in a row, with gaps between each filter element. These gaps are used for the flow of coal and water.

[0021] The microcrystalline filter tank 2 is divided into an ash accumulation zone 23 and a filtration zone 24, and a filter element group 21 is installed at the top of the clear water tank 25. The filter element is installed at the top of the opening of the clear water tank 25.

[0022] The upper port 6 is near the top of the ash accumulation zone 23, and the lower port 7 is near the bottom of the filtration zone 24. The bottom of the ash accumulation zone 23 is lower than the bottom of the filtration zone 24, which facilitates the sedimentation of coal sludge in the coal water to the bottom of the ash accumulation zone 23.

[0023] The filter element group includes one or more filter elements; multiple filter elements are arranged longitudinally, and each filter element is vertically bonded to each other; each filter element is made of alumina, silicon carbide, microcrystalline ceramic particles, mixed with binder, pore-forming agent, and corrosion inhibitor, and is formed into a column or strip shape by pressing and high-temperature sintering, and has micron-sized pores.

[0024] like Figure 4 As shown, multiple filter elements are longitudinally bonded together.

[0025] The functions of the filter tuple are as follows: 1. Except for hydrofluoric acid, it has extremely excellent corrosion resistance to all corrosive substances.

[0026] 2. It has good heat resistance and is suitable for high-temperature environments below 200°C. It will not deform, crack, or age under rapid heating and cooling conditions.

[0027] 3. It has good mechanical strength and high rigidity, and its shape does not change and its aperture does not deform under fluid pressure.

[0028] 4. High filtration precision and high particle retention efficiency. Within a certain limit, particles larger than the micropore diameter will absolutely not pass through.

[0029] 5. It has stable chemical properties, no leaching, and will not produce secondary pollution. It has no effect on the filtered liquids or gases.

[0030] 6. Long service life (over 15 years), easy regeneration, and low operating costs.

[0031] The microcrystalline filter 4 is connected to the intermediate water tank 3 via the coal-water inlet pipe 8. In this embodiment, a coal-water booster pump is preferably installed on the coal-water inlet pipe 8. The microcrystalline filter 4 is connected to the reuse water tank 5 via the guide pipe 9. The microcrystalline filter 4 includes a shell and filter media, with the filter media filling the shell.

[0032] The filter media utilizes rare earth elements, pore-forming agents, and binder additives, undergoing processes such as sludge preparation, aging, molding, drying, firing, and sieving to produce high-efficiency microcrystalline filter media. The filter media has a particle size of 0.5–6 mm, a specific gravity of 1.8–2.3, and is characterized by its hardness, white color, and numerous micropores. This effectively meets hydraulic requirements, reduces backwash water volume, increases the filtration surface area, and particularly expands the adsorption area, thus significantly improving the filter media's ability to remove contaminants, increasing water production and quality. Its numerous pores and large specific surface area make it a novel type of filter media suitable for removing colloidal substances from water. Microcrystalline filter media possesses both mechanical filtration and physical adsorption characteristics, with a well-developed microporous structure and a large specific surface area, exhibiting a strong adsorption capacity for suspended solids and dissolved organic matter in water. According to design requirements, microcrystalline filter media of different specifications and specific gravities are graded and filled. The surface of the filter media can block large particles of impurities, which is called mechanical blocking. Small impurities can be temporarily retained in a position inside the pores due to instantaneous changes in flow velocity and electrostatic adsorption. This is a metastable state, which is adsorption. The presence of metastable particles promotes a larger surface area, thus adsorbing even smaller impurities. This is called filtration by slag. This multi-layered, composite, and volumetric interception principle greatly improves filtration efficiency.

[0033] Microcrystalline filter media has advantages such as stable chemical properties, abrasion resistance, impact resistance, no dusting, acid and alkali resistance, corrosion resistance, high temperature resistance, low temperature resistance, large specific surface area, strong interception capacity, good adsorption performance, uniform particle size, moderate specific gravity, and permanent lifespan. It solves the technical problems of natural filter media having a single specific gravity and being unable to meet the needs of complex water treatment engineering, and solves the problems of easy mud formation and secondary pollution caused by silica and organic carbon in filter media such as quartz sand and anthracite.

[0034] In this embodiment, an outlet pipe 91 and a backwash inlet pipe 92 are also provided. One end of the guide pipe 9 is connected to the outer shell, and the other end of the guide pipe 9 is connected to the backwash inlet pipe 91 and the outlet pipe 92 respectively through a tee. The end of the outlet pipe 92 away from the guide pipe 9 extends into the coal-water reuse tank 5, and the end of the backwash inlet pipe 91 away from the guide pipe 9 extends into the coal-water reuse tank 5.

[0035] In this embodiment, the interface between the guide pipe 9 and the microcrystalline filter 4 is higher than the interface between the inlet pipe 8 and the microcrystalline filter 4, so that the coal water injected into the microcrystalline filter 4 from the inlet pipe 8 flows from bottom to top to the guide pipe 9, and then flows through the outlet pipe 91 to the coal water reuse tank 5.

[0036] A backwash pump is installed on the backwash inlet pipe 92. The purified water in the reuse water tank 5 flows to the microcrystalline filter 4 through the backwash pump, the backwash inlet pipe 92, and the guide pipe 9. In another embodiment, the bottom end of the microcrystalline filter 4 is provided with a backwash water outlet, which is connected to the coal-water sedimentation tank 1 through the backwash slag discharge pipe 10.

[0037] The coal-water reuse tank 5 is connected to the coal washing system 12 via a coal-water reuse pump and a water pipe, and is used for coal washing operations.

[0038] A method for treating coal-containing wastewater includes the following steps: S1. Coal water flows into coal water sedimentation tank 1 through coal-containing wastewater pipeline 11 in the plant area; S2, Coal water overflows into ash accumulation area 23; S3. Coal water flows by gravity from ash accumulation zone 23 to filtration zone 24; S4. Coal sludge in the coal water settles to the bottom of the ash accumulation zone 23 and the filtration zone 24; S5. Coal-fired water flows through filter element 21 to the clean water zone at the bottom of filter zone 24. S6, the coal water at the bottom of the filtration zone 24 flows into the intermediate water tank 3; S7. The coal water in the intermediate water tank 3 is pumped into the microcrystalline filter 4 through the water inlet pipe 8. S8. The coal water is treated by the microcrystalline filter 4 and flows to the coal water reuse tank 5 through the guide pipe 9 and the outlet pipe 91 in sequence. S9. When it is necessary to flush the microcrystalline filter 4, start the backwash pump of the backwash inlet pipe 92. Clean water backwashes the microcrystalline filter 4 through the backwash inlet pipe 92 and the guide pipe 9. The coal slurry in the microcrystalline filter 4 flows to the coal-water sedimentation tank 1 through the backwash discharge pipe 10.

[0039] In this embodiment, the sedimentation tank, filtration tank, and intermediate water tank are all constructed in a co-current manner, while the reuse tank can be constructed in a co-current manner or independently. The water to be filtered after passing through the filter elements enters the intermediate water tank and is then pumped through the inlet pipe into the microcrystalline filter. After filtration, the water flows through the outlet pipe into the reuse tank. The clean water in the reuse tank is returned to the water usage area for recycling via a reuse pump. The backwash pump in the reuse tank draws clean water from the microcrystalline filter and enters the filter through the backwash inlet pipe to rinse the microcrystalline filter media. The washed-off sludge is discharged into the sedimentation tank through the backwash outlet pipe.

[0040] Example 2 Reference Figure 5 As shown, based on Example 1, two sets of coal-water sedimentation tanks 1, microcrystalline filter tanks 2, filter element groups 21, ash accumulation area 23, filtration area 24, intermediate water tank 3, microcrystalline filter 4, upper port 6, lower port 7, inlet pipe 8, guide pipe 9, outlet pipe 91, backwash inlet pipe 92, backwash slag discharge pipe 10, and coal-containing wastewater pipeline 11 are set up. A set of coal-water reuse tank 5 and coal washing system 12 are also set up. In this example, the inlet pipes 8 of the two sets of coal-water treatment devices are connected through a spare pipe 13, and a spare pump is installed on the spare pipe 13.

[0041] If one of the coal-water treatment units malfunctions, the coal-water can be pumped to a working coal-water treatment unit via the backup pipe 13 for further treatment.

[0042] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A coal-containing wastewater treatment device, characterized in that, include: Coal-water sedimentation tank (1), microcrystalline filter tank (2), intermediate water tank (3), microcrystalline filter (4), and coal-water reuse tank (5); The coal-water sedimentation tank (1) is connected to the microcrystalline filter tank (2) through the upper port (6), and the microcrystalline filter tank (2) is connected to the intermediate water tank (3) through the lower port (7). The microcrystalline filter tank (2) is provided with a filter element group (21), which is located between the upper port (6) and the lower port (7), and the upper port (6) is higher than the lower port (7). The microcrystalline filter (4) is pumped to the intermediate water tank (3) through the water inlet pipe (8); The microcrystalline filter (4) is connected to the reclaimed water tank (5) through a guide pipe (9).

2. The coal-containing wastewater treatment device according to claim 1, characterized in that, The coal-water sedimentation tank (1) is connected to the coal-containing wastewater pipeline (11) on one side of the microcrystalline filter tank (2).

3. The coal-containing wastewater treatment device according to claim 1, characterized in that, The microcrystalline filter (2) is divided into an ash accumulation zone (23) and a filtration zone (24). The ash accumulation area (23) is adjacent to the upper port (6), and the coal-water sedimentation tank (1) is connected to the ash accumulation area (23) through the upper port (6); The filtration zone (24) is adjacent to the lower port (7), and the filtration zone (24) is connected to the intermediate water tank (3) through the lower port (7); The filter element group (21) is disposed inside the filter zone (24).

4. The coal-containing wastewater treatment device according to claim 3, characterized in that, The upper port (6) is adjacent to the top of the ash accumulation area (23); The lower port (7) is located near the bottom of the filter area (24).

5. The coal-containing wastewater treatment device according to claim 3, characterized in that, The bottom of the ash accumulation zone (23) is lower than the bottom of the filtration zone (24).

6. The coal-containing wastewater treatment device according to claim 1, characterized in that, The filter element group (21) includes one or more filter cartridges; Multiple filter elements are arranged longitudinally, and each filter element is vertically bonded to each other; Each filter element is made of alumina, silicon carbide, microcrystalline ceramic particles, mixed with binders, pore-forming agents, and corrosion inhibitors, and is formed by pressing and high-temperature sintering.

7. The coal-containing wastewater treatment device according to claim 1, characterized in that, The microcrystalline filter (4) includes: a housing and filter media, wherein the filter media is filled inside the housing.

8. The coal-containing wastewater treatment device according to claim 7, characterized in that, It also includes an outlet pipe (91) and a backwash inlet pipe (92); One end of the guide pipe (9) is connected to the outer shell, and the other end of the guide pipe (9) is connected to the water outlet pipe (91) and the backwash water inlet pipe (92) respectively through a tee. The end of the outlet pipe (91) away from the guide pipe (9) extends into the coal-water reuse pool (5); The end of the backwash inlet pipe (92) away from the guide pipe (9) is connected to the backwash water pump and extends into the coal-water reuse tank (5).

9. A method for treating coal-containing wastewater, characterized in that, The treatment of coal-containing wastewater using the apparatus described in any one of claims 1-8 includes the following steps: S1. Coal water flows into the coal water sedimentation tank (1) through the coal-containing wastewater pipeline (11) in the plant area. S2, Coal water overflows into the ash accumulation area (23); S3, Coal water flows by gravity from the ash accumulation area (23) to the filtration area (24); S4. Coal sludge filtered by the filter element in the coal water settles to the bottom of the ash accumulation zone (23) and the filtration zone (24); S5. Coal water flows through the filter element to the clear water tank at the bottom of the filtration zone (24); S6. The coal water at the bottom of the filtration zone (24) flows into the intermediate water tank (3) through the clear water tank; S7. The coal water in the intermediate water tank (3) is pumped into the microcrystalline filter (4) through the coal water inlet pipe (8); S8. The coal water is treated by the microcrystalline filter (4) and flows to the coal water reuse tank (5) through the guide pipe (9) and the outlet pipe (91) in sequence. S9. When the microcrystalline filter (4) needs to be rinsed, start the backwash pump connected to the backwash inlet pipe (92) and clean water backwashes the microcrystalline filter (4) through the backwash inlet pipe (92) and the guide pipe (9).