System for treating coal mine acid wastewater by curing red mud particles

Abstract

The utility model discloses a system for treating coal mine acid wastewater by curing red mud particles, which relates to the field of coal mine acid wastewater treatment and is characterized by comprising a reaction tank, a first valve and the red mud particles, a red mud feeding port capable of being opened and closed is formed in the top of the reaction tank, a red mud discharging port is formed in the bottom surface of the reaction tank, the first valve is mounted at the red mud discharging port, and a water inlet and a water outlet are formed in the top of the reaction tank; the filling height of the red mud particles in the reaction tank is lower than that of the water outlet. According to the utility model, automatic separation of mud and water is realized by virtue of density characteristics and gravity action of red mud particles and water, filtering devices which are easy to block, such as dynamic membranes, do not need to be used, and frequent shutdown and maintenance are not needed.

Description

Technical Field

[0001] The utility model relates to the field of coal mine acid wastewater treatment, and more specifically, it relates to a system for treating coal mine acid wastewater with solidified red mud particles. Background Art

[0002] Acid wastewater is generated during the coal mining and utilization processes. If this acid wastewater is directly discharged into lakes, rivers, and seas without effective treatment, it will seriously pollute the water bodies and thus damage the ecological balance. Red mud is a waste product in alumina production. Most alumina plants store red mud in tailing ponds, resulting in a serious risk of alkali pollution to the soil and groundwater. In recent years, red mud has been used as a lime substitute for treating coal mine acid wastewater, effectively reducing the economic costs of treating red mud and coal mine acid wastewater, and at the same time reducing the harmfulness of red mud and coal mine acid wastewater to the environment.

[0003] Chinese invention patent application CN101423306A provides a treatment device for acid wastewater from high-phosphorus hematite beneficiation, which includes a mixer, a coagulation tank, a connecting pipe, and a dynamic membrane reactor; the dynamic membrane reactor includes a sludge discharge pipe, a water outlet pipe, a reactor body, a dynamic membrane carrier, an aeration head, an aerator, and an aeration pipe; the coagulation tank is a cavity, the stirring blades of the mixer are located in the cavity of the coagulation tank, the lower part of the cavity of the coagulation tank is connected to the lower part of the cavity of the reactor body of the dynamic membrane reactor through a connecting pipe, and a control valve is arranged on the connecting pipe; the reactor body is a cavity, the dynamic membrane carrier and the aeration head are respectively located in the cavity of the reactor body, the aeration head is located below the dynamic membrane carrier, and the aeration head is connected to the aerator through an aeration pipe; a sludge discharge pipe is arranged at the bottom of the reactor body, a control valve is arranged on the sludge discharge pipe, and the inlet end of the water outlet pipe is located in the upper part of the cavity of the reactor body.

[0004] The above device mixes red mud powder and acid wastewater into a muddy water mixture through the mixer and the coagulation tank, and filters the muddy water mixture through the dynamic membrane reactor to obtain reusable acid-purified water. However, during use, the dynamic membrane carrier in the dynamic membrane reactor is extremely easy to be blocked by red mud particles. Therefore, the above device needs to be frequently shut down for cleaning the dynamic membrane carrier. Content of the Utility Model

[0005] Aiming at the problem that the dynamic membrane carrier in the prior art is extremely easy to be blocked by red mud particles, the purpose of the utility model is to provide a system for treating coal mine acid wastewater with solidified red mud particles, which includes a reaction tank, a first valve, and red mud particles. The reaction tank is provided with an openable and closable red mud feeding port at the top, a red mud discharging port at the bottom surface, the first valve is installed at the red mud discharging port, and the reaction tank is provided with a water inlet and a water outlet at the top. The filling height of the red mud particles in the reaction tank is lower than the water outlet.

[0006] The present utility model is further configured as: it further includes a three-way pipe fitting, a second valve, a third valve, and a filter screen. The outlet of the first valve, the inlet of the second valve, and the inlet of the third valve are respectively connected to the three pipe heads of the three-way pipe fitting. The filter screen is fixedly connected to the second valve.

[0007] The present utility model is further configured as: it further includes a pumping station, and the pumping station is connected to the outlet of the third valve.

[0008] The present utility model is further configured as: it further includes a water inlet pipe. One end of the water inlet pipe is located outside the reaction tank, and the other end of the water inlet pipe is inserted into the reaction tank from the water inlet and submerged in the red mud particles.

[0009] The present utility model is further configured as: the axis of the reaction tank is vertical, and the axis of the part of the water inlet pipe inserted into the reaction tank is collinear with the axis of the reaction tank.

[0010] The present utility model is further configured as: the inner bottom surface of the reaction tank is an inverted conical surface or a bowl-shaped surface, and the water outlet is located at the lowest point of the inner bottom surface of the reaction tank.

[0011] The present utility model is further configured as: the inner bottom surface of the reaction tank is an inverted conical surface.

[0012] The present utility model is further configured as: the porosity of the red mud particles in the reaction tank is 30%-60%.

[0013] The present utility model is further configured as: it further includes a flow rate control device, and the flow rate control device is connected to the end of the water inlet pipe located outside the reaction tank.

[0014] The present utility model is further configured as: the reaction tank is a PVC reaction tank.

[0015] In summary, the present utility model has the following beneficial effects compared with the prior art: When the system is in use, the coal mine acidic wastewater enters the reaction tank from the water inlet, and under the action of its own gravity, it seeps into the gaps between the red mud particles and makes full contact with the red mud particles. Since the density of the red mud particles is greater than the density of water, the red mud particles will deposit in the reaction tank under the action of their own gravity. As the amount of water in the reaction tank increases, the coal mine acidic wastewater is purified by the red mud particles and discharged from the water outlet. This system realizes the automatic separation of mud and water by means of the density characteristics of the red mud particles and water and the action of gravity, without using a filtering device such as a dynamic membrane that is prone to blockage, and without frequent shutdown for maintenance. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of Embodiment 1.

[0017] In the figure: 1, reaction tank; 11, water outlet; 2, first valve; 3, second valve; 4, third valve; 5, water inlet pipe; 6, red mud particles; 7, tee fitting; 8, slurry discharge pipe; 9, sludge discharge pipe. Detailed implementation mode

[0018] The technical solution of the present utility model will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the utility model.

[0019] It should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "horizontal", "left", "right", "front", "rear", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0020] Embodiment 1

[0021] As Figure 1 shown, a system for treating coal mine acid wastewater with solidified red mud particles includes a reaction tank 1, a first valve 2 and red mud particles 6. The reaction tank 1 is provided with an openable and closable red mud feeding port at the top, which is not shown in the figure. The bottom surface of the reaction tank 1 is provided with a red mud discharge port, and the first valve 2 is installed at the red mud discharge port. The reaction tank 1 is provided with a water inlet and a water outlet 11 at the top. The filling height of the red mud particles 6 in the reaction tank 1 is lower than the water outlet 11 to reduce the possibility of the red mud particles 6 leaving the reaction tank 1 from the water outlet 11.

[0022] When this system is in use, the first valve 2 is normally closed. The coal mine acid wastewater enters the reaction tank 1 from the water inlet and seeps into the gaps between the red mud particles 6 under its own gravity, and makes full contact with the red mud particles 6. Since the density of the red mud particles 6 is greater than the density of water, the red mud particles 6 will deposit in the reaction tank 1 under their own gravity. As the water volume in the reaction tank 1 increases, the coal mine acid wastewater is purified by the red mud particles 6 and discharged from the water outlet 11. By detecting the liquid discharged from the water outlet 11, when the red mud in the reaction tank 1 cannot effectively purify the coal mine acid wastewater, the first valve 2 is opened to discharge the mud-water mixture in the reaction tank 1, so as to facilitate the input of new red mud particles 6 into the reaction tank 1. This system realizes the automatic separation of mud and water by means of the density characteristics of the red mud particles 6 and water and the gravity action, without using a filtering device such as a dynamic membrane that is prone to blockage, and thus there is no need for frequent shutdown maintenance.

[0023] This embodiment further includes a three-way pipe fitting 7, a second valve 3, a third valve 4, and a filter screen. The outlet of the first valve 2, the inlet of the second valve 3, and the inlet of the third valve 4 are respectively connected to the three pipe ends of the three-way pipe fitting 7. The filter screen is fixedly connected to the second valve 3, and the filter screen is used to filter all the fluid flowing through the second valve 3. In this embodiment, the second valve 3 and the third valve 4 are normally closed. When the red mud in the reaction tank 1 cannot effectively purify the coal mine acid wastewater, first open the first valve 2 and the second valve 3. The mud-water mixture in the reaction tank 1 is divided into slurry and muddy waste by the filter screen. The slurry flows out from the second valve 3, and the muddy waste is intercepted by the filter screen. After the slurry is drained, close the second valve 3 and open the third valve 4. The muddy waste is discharged through the first valve 2 and the third valve 4. The filter screen is not shown in the figure.

[0024] During the use of this system, a large amount of iron oxides will be generated by the chemical reaction in the reaction tank 1. These iron oxides will deposit at the bottom of the reaction tank 1. Through the filtration of the filter screen, the slurry containing iron oxides can be recovered for the secondary utilization of iron oxides.

[0025] This embodiment further includes a pumping station, which is connected to the outlet of the third valve 4. The pumping station is used to accelerate the flow rate of the muddy waste at the third valve 4 and improve the discharge efficiency of the muddy waste. The pumping station is not shown in the figure.

[0026] This embodiment further includes a water inlet pipe 5. One end of the water inlet pipe 5 is located outside the reaction tank 1, and the other end of the water inlet pipe 5 is inserted into the reaction tank 1 from the water inlet and submerged in the red mud particles 6. The coal mine acid wastewater enters the reaction tank 1 through the water inlet pipe 5. The greater the depth of the water inlet pipe 5 inserted into the red mud particles 6, the longer the contact time between the coal mine acid wastewater and the red mud particles 6, and the better the purification effect.

[0027] Specifically, the axis of the reaction tank 1 is vertical, and the axis of the part of the water inlet pipe 5 inserted into the reaction tank 1 is collinear with the axis of the reaction tank 1, so as to facilitate the uniform contact between the coal mine acid wastewater output by the water inlet pipe 5 and the red mud particles 6 around the water inlet pipe 5.

[0028] Specifically, the inner bottom surface of the reaction tank 1 is an inverted conical surface or a bowl-shaped surface, and the water outlet 11 is located at the lowest point of the inner bottom surface of the reaction tank 1, so as to facilitate guiding the mud-water mixture in the reaction tank 1 to be discharged from the first valve 2. In this embodiment, the inner bottom surface of the reaction tank 1 is an inverted conical surface.

[0029] Specifically, the porosity of the red mud particles 6 in the reaction tank 1 is 30%-60% to ensure the fluidity of the coal mine acid wastewater between the red mud particles 6.

[0030] Specifically, it further includes a flow rate control device, which is connected to one end of the water inlet pipe 5 outside the reaction tank 1 to control the uniform and slow entry of coal mine acidic wastewater into the reaction tank 1, ensuring the contact time between the coal mine acidic wastewater and the red mud particles 6 and improving the purification effect. The flow rate control device is not shown in the figure.

[0031] Specifically, the reaction tank 1 is a PVC reaction tank. PVC, also known as polyvinyl chloride, is light in weight and not easily corroded.

[0032] Specifically, this embodiment further includes a slurry discharge pipe 8 and a sludge discharge pipe 9. The slurry discharge pipe 8 is connected to the outlet of the second valve 3, and the sludge discharge pipe 9 is connected to the outlet of the third valve 4.

[0033] In summary, when this system is in use, the coal mine acidic wastewater enters the reaction tank 1 from the water inlet and seeps into the gaps between the red mud particles 6 under its own gravity, making full contact with the red mud particles 6. Since the density of the red mud particles 6 is greater than that of water, the red mud particles 6 will deposit in the reaction tank 1 under their own gravity. As the water volume in the reaction tank 1 increases, the coal mine acidic wastewater is purified by the red mud particles 6 and discharged from the water outlet 11. This system realizes the automatic separation of mud and water by leveraging the density characteristics of the red mud particles 6 and water and the gravity effect, without the need to use filtration devices such as dynamic membranes that are prone to clogging, and without the need for frequent shutdown maintenance.

[0034] Example 2

[0035] In this embodiment, a system described in Example 1 was constructed. Among them, the inner diameter of the reaction tank is 100 cm, the inner height of the reaction tank is 200 cm, red mud particles with a diameter of 1 - 2 cm are filled in the reaction tank, and the porosity of the red mud particles in the reaction tank is 40%.

[0036] Select the acidic wastewater gushing out from a certain closed coal mine as the treatment object (sample number S0), and its main components and concentrations are shown in Table 1.

[0037] Table 1 Composition Table of Acidic Wastewater from a Certain Closed Coal Mine

[0038] Sample Number Fe (mg / L) Mn (mg / L) Al (mg / L) pH S0 75.6 0.14 18 4.05

[0039] Adjust the coal mine acidic wastewater to enter the water inlet pipe at a flow rate of 18 tons of water per day, and continuously feed water into the reaction tank for 180 days.

[0040] Open the first valve and the second valve once every 30 days to recover the slurry with iron oxides. After the slurry recovery is completed, close the second valve, open the third valve, discharge 0.5 cubic meters of muddy waste, and then close the first valve and the third valve, and replenish 0.5 cubic meters of red mud particles with a diameter of 1 - 2 cm into the reaction tank.

[0041] On the 20th day, 40th day, and 60th day of continuous water inlet into the reaction tank, the water composition at the outlet of the system is shown in Table 2.

[0042] Table 2 System Drainage Composition Table

[0043] Fe (mg / L) Mn (mg / L) Al (mg / L) pH Day 20 8.5 0.11 4.2 8.2 Day 40 10.6 0.08 5.6 7.6 Day 60 7.6 0.12 3.9 6.8

[0044] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A system for treating coal mine acidic wastewater with solidified red mud particles, characterized in that: It includes a reaction tank (1), a first valve (2) and red mud particles (6); an openable and closable red mud feeding port is provided at the top of the reaction tank (1), a red mud discharging port is provided at the bottom surface of the reaction tank (1), the first valve (2) is installed at the red mud discharging port, a water inlet and a water outlet (11) are provided at the top of the reaction tank (1); the filling height of the red mud particles (6) in the reaction tank (1) is lower than the water outlet (11).

2. The system for treating coal mine acid wastewater with solidified red mud particles according to claim 1, wherein: It further includes a three-way pipe fitting (7), a second valve (3), a third valve (4) and a filter screen; the outlet of the first valve (2), the inlet of the second valve (3) and the inlet of the third valve (4) are respectively connected to the three pipe heads of the three-way pipe fitting (7); the filter screen is fixedly connected to the second valve (3).

3. The system for treating coal mine acid wastewater with solidified red mud particles according to claim 2, characterized in that: It further includes a pumping station, and the pumping station is connected to the outlet of the third valve (4).

4. The system for treating coal mine acid wastewater with solidified red mud particles according to any one of claims 1-3, characterized in that: It further includes a water inlet pipe (5), one end of the water inlet pipe (5) is located outside the reaction tank (1), and the other end of the water inlet pipe (5) is inserted into the reaction tank (1) from the water inlet and submerged in the red mud particles (6).

5. The system for treating coal mine acid wastewater with solidified red mud particles according to claim 4, wherein: The axis of the reaction tank (1) is vertical, and the axis of the part of the water inlet pipe (5) inserted into the reaction tank (1) is collinear with the axis of the reaction tank (1).

6. The system for treating coal mine acid wastewater with solidified red mud particles according to any one of claims 1-3, characterized in that: The inner bottom surface of the reaction tank (1) is an inverted conical surface or a bowl-shaped surface, and the water outlet (11) is located at the lowest point of the inner bottom surface of the reaction tank (1).

7. The system for treating coal mine acid wastewater with solidified red mud particles according to claim 6, characterized in that: The inner bottom surface of the reaction tank (1) is an inverted conical surface.

8. The system for treating coal mine acid wastewater with solidified red mud particles according to any one of claims 1-3, characterized in that: The porosity of the red mud particles (6) in the reaction tank (1) is 30%-60%.

9. The system for treating coal mine acid wastewater with solidified red mud particles according to any one of claims 1-3, characterized in that: It further includes a flow rate control device, and the flow rate control device is connected to the end of the water inlet pipe (5) located outside the reaction tank (1).

10. The system for treating coal mine acid wastewater with solidified red mud particles according to any one of claims 1-3, characterized in that: The reaction tank (1) is a PVC reaction tank.

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