In-situ pretreatment system for acidic wastewater in strip mine pit

Abstract

An overflow plate (7) is arranged between a dissolving tank (1) and a pumping tank (2), a latticed aeration pipeline (6) is arranged in the dissolving tank (1), a pump tank (3) is arranged at the bottom of the pumping tank (2), a slurry pump (8) is mounted in the pump tank (3), and an outlet of the slurry pump (8) is connected with a conveying pipeline (9); a pontoon (12) is arranged in the strip mine pit (4), the pontoon (12) is connected with a dosing pipeline (11), dosing holes are uniformly distributed in the surface of the dosing pipeline (11), and an outlet of the conveying pipeline (9) is connected with an inlet of the dosing pipeline (11) through a metal hose (10). According to the utility model, the pH value of the water body in the strip mine pit can be rapidly increased, the concentration of heavy metal ions is reduced, the usage amount of alkaline agents and flocculants during centralized treatment is reduced, and the operation cost of a centralized sewage treatment station is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of mine water environment treatment, in particular to an acidic water treatment system of a mine, and is particularly suitable for in-situ pretreatment of acidic water in an open-pit mine. Background Art

[0002] Since my country has a large number of sulfur-containing mineral resources, and most of them are of the ore deposit type, there are a huge number of open-pit mines left over from mining, which are spread all over the country. In the process of receiving rainwater and slope leaching water on a daily basis, open-pit mines often produce a large amount of acidic wastewater under the action of air and microorganisms and accumulate in the open-pit mines. Because the wastewater from open-pit mines has a large amount of water, low pH, and high concentration of heavy metal ions. If engineering measures are adopted to lift the wastewater to the acid water treatment station for centralized treatment, although the treatment effect is good, there are still some problems, which are specifically manifested in: First, although the commonly used acid water treatment agents (such as liquid alkali) have good effects, the unit price of the agents is high, and the cost of the agents is high when treating a large amount of wastewater; second, the heavy metal content of the wastewater is high, and the amount of flocculant required is large; third, the amount of sludge produced after neutralization is large, which increases the cost of sludge disposal. Therefore, there is an urgent need for a pretreatment system that can improve the water quality of acid wastewater before centralized treatment of acid water. Summary of the invention

[0003] The utility model aims to provide an open-pit mine acid wastewater in-situ pretreatment system that can effectively increase the pH value of the water body and reduce the heavy metal concentration before the centralized treatment of the acid wastewater, in order to solve the problems of large amount of reagents used and large amount of sludge generated in the existing open-pit mine acid wastewater centralized treatment.

[0004] In order to achieve the above-mentioned purpose of the utility model, the utility model adopts the following technical scheme for the in-situ pretreatment system of acid wastewater in open-pit mines:

[0005] The utility model discloses an in-situ pretreatment system for acid wastewater in an open-pit mine, which comprises a dissolving tank and a pumping tank. An overflow plate is arranged between the dissolving tank and the pumping tank. The two water tanks are separated by an overflow baffle. The supernatant (alkaline solution) in the dissolving tank goes over the overflow plate and enters the pumping tank. The solution is pumped into a conveying pipeline by a slurry pump arranged in the pumping tank. A grid-shaped aeration pipeline is arranged in the dissolving tank. A pump trough is arranged at the bottom of the pumping tank. The pump trough is used to collect undissolved alkaline reagents. A slurry pump is installed in the pump trough. The outlet of the slurry pump is connected to the conveying pipeline. A floating boat is arranged in the open-pit mine. The floating boat is connected to a dosing pipeline with dosing holes evenly arranged on the surface. The outlet of the conveying pipeline is connected to the inlet of the dosing pipeline through a metal hose. The dissolving tank and the pumping tank are combined to form a reaction tank, which is an alkaline neutralizing material adding area. The alkaline reagent is dissolved in the dissolving tank to form a solution, and is conveyed to the open-pit mine through the pumping tank. The grid-shaped aeration pipeline fully dissolves the alkaline reagent to form an alkaline material suspension. The dosing pipeline and the floating boat constitute a drug spreading device, which plays a role in evenly spreading the alkaline solution.

[0006] Furthermore, high-pressure water gun nozzles are installed at multiple points on the wall of the dissolving tank, and the water inlet of the high-pressure water gun nozzle is connected to an external water source, which dissolves the solid medicine and pushes the medicine forward at the same time.

[0007] Furthermore, the dissolution tank and the pumping tank are combined to form a reaction tank, and the reaction tank is set with a slope of 1 to 2% from front to back to enhance the fluidity of the solution and the solid medicine.

[0008] Furthermore, it also contains a submersible mixer, which is installed in an open pit. The function of the submersible mixer is to stir the surrounding water, increase the diffusion speed of the alkaline agent, and accelerate the neutralization of acid and alkali.

[0009] Furthermore, a driving device capable of driving the dosing pipeline to move on the water surface of the open pit is installed on the floating boat. The driving device drives the floating boat to drive the dosing pipeline to move on the water surface, thereby completing the spreading of alkaline agents in a large area of ​​water.

[0010] After the above technical scheme is adopted in the in-situ pretreatment system of acid wastewater from open pit mines of the utility model, the acid wastewater from the open pit mines has the following beneficial effects after the above pretreatment:

[0011] (1) Through the high-pressure water gun nozzle and grid-shaped aeration pipe of the reaction tank, the solid alkaline agent can fully and quickly dissolve in water to form an alkaline solution in a short time, quickly raising the pH of the mine water;

[0012] (2) Through the movement of the floating boat on the water surface, the dosing pipeline can move on the water surface, expanding the scope of alkaline dosing and being applicable to the pretreatment of large-scale mine wastewater.

[0013] (3) By adding alkaline agents in situ, the pH value of the mine raw water is increased, the concentration of heavy metal ions is reduced, and the amount of alkaline agents and flocculants used in centralized treatment can be saved.

[0014] (4) By adding reagents in situ, heavy metal ions settle in the mine, reducing the amount of sludge generated during centralized treatment and saving sludge disposal costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the plan structure of an in-situ pretreatment system for acidic wastewater in an open-pit mine according to the utility model;

[0016] Figure 2 The utility model is a schematic cross-sectional view of the structure of an in-situ pretreatment system for acid wastewater in an open-pit mine.

[0017] Figure numerals: 1-dissolution tank; 2-pumping tank; 3-pump tank; 4-open pit; 5-high-pressure water gun nozzle (connected to external water source); 6-grid aeration pipe (connected to external air compressor); 7-overflow plate; 8-slurry pump; 9-transportation pipe; 10-metal hose; 11-dosing pipe; 12-floating boat (with drive device and infrared ranging sensor); 13-submersible mixer. DETAILED DESCRIPTION

[0018] In order to better describe the present invention, an open-pit mine acid wastewater in-situ pretreatment system of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0019] Depend on Figure 1 The schematic diagram of the plan structure of an in-situ pretreatment system for acidic wastewater from an open pit of the utility model is shown in combination with Figure 2 It can be seen that in the embodiment, the utility model is an in-situ pretreatment system for acidic wastewater in an open-pit mine, comprising a dissolution tank 1 and a pumping tank 2. The dissolution tank 1 and the pumping tank 2 are combined to form a reaction tank. The reaction tank is set with a slope of 1% from front to back. An overflow plate 7 is provided between the dissolution tank 1 and the pumping tank 2. The overflow plate 7 intercepts solid particles mixed in the reagent; a grid-like aeration pipe 6 is installed at the bottom of the dissolution tank 1, and the grid-like aeration pipe 6 is connected to an external air compressor through a pipe. The grid-like aeration pipe 6 has holes and ventilation to stir the reagent; a high-pressure water gun nozzle 5 is installed on the wall of the dissolution tank 1, and the water inlet of the high-pressure water gun nozzle 5 is connected to an external water source to strengthen the horizontal flow of the reagent and also has a stirring effect; a pump tank 3 is provided at the bottom of the pumping tank 2, and a slurry pump 8 is installed in the pump tank 3. The outlet of the slurry pump 8 is connected to the conveying pipe 9, and the slurry pump 8 will enter the pump The solid particles in the delivery pool 4 are pumped to the open-pit mine 4, and the delivery pipeline 9 delivers the reagent to the open-pit mine 4; a floating boat 12 is placed in the open-pit mine 4, and the floating boat 12 is connected to the dosing pipeline 11 with dosing holes evenly distributed on the surface. The surface of the dosing pipeline 11 has evenly distributed holes, which plays a role in evenly spreading the reagent; the outlet of the delivery pipeline 9 is connected to the inlet of the dosing pipeline 11 through a metal hose 10, and the metal hose 10 as a connecting part allows the subsequent pipeline to swing at a certain angle; a driving device capable of driving the dosing pipeline 11 to move on the water surface of the open-pit mine 4 is installed at the lower part of the floating boat 12, and two infrared ranging sensors are also installed on the floating boat 12. When the floating boat 12 is 10 meters away from the side wall of the open-pit mine 4, the infrared ranging sensor measures the distance, and the signal is transmitted to the driving device to drive the floating boat 12 to move in the opposite direction, thereby driving the dosing pipeline 11 to move automatically on the water surface. In addition, the utility model also includes a submersible mixer 13, which is installed in the open pit 4. The submersible mixer 13 expands the reaction range of the reagent by pushing the bottom water flow.

[0020] The following takes the acid wastewater treatment of a large open-pit mine in East China as an example to explain the acid water pretreatment system:

[0021] The mine contains about 3 million cubic meters of acidic wastewater, with a pH of 2 to 3, an iron ion concentration of 33 mg / L, and a manganese ion concentration of 62 mg / L. In response to the acidic wastewater from the open-pit mine, an acid water treatment station with "flocculation precipitation + acid-base neutralization" as the main process has been established. The acidic wastewater from the open-pit mine is pumped to the acid treatment station for treatment and then discharged after meeting the standards. However, the acid water treatment station has problems such as "large amount of flocculants, large amount of alkaline reagents (NaOH), and large amount of sludge produced". In view of the current status of the open-pit mine and the acid water treatment station, an in-situ pretreatment system for acidic wastewater from the open-pit mine was established.

[0022] When the in-situ pretreatment system for acidic wastewater of the utility model is used to pretreat acidic wastewater of an open pit, the alkaline agent is slaked lime (Ca(OH)2), which is added into the dissolution tank 1. Under the action of the high-pressure water gun nozzle 5 and the grid-shaped aeration pipe 6, the dissolved slaked lime solution enters the pumping tank 2 through the overflow plate 7, and the undissolved slaked lime enters the pumping tank 2 through the holes below the overflow plate 7 for further dissolution. Impurities are accumulated in the pump tank 8 to be reused or cleaned up, and the solution and small particles of slaked lime are pumped into the conveying pipe 9 by the slurry pump 8, and then evenly spread in the open pit 4 through the floating boat 12 and the dosing pipe 11, and finally spread in the water around the spreading point through the submersible mixer 13 to accelerate the reaction of the slaked lime solution and the acidic wastewater.

[0023] After pretreatment, the pH of the acid wastewater from the open pit increased to 5-6, the iron ion concentration decreased to 10 mg / L, and the manganese ion concentration decreased to 22 mg / L. While reducing the amount of NaOH used in the acid water treatment station, the amount of flocculant used and the amount of sludge produced were also greatly reduced. The system effectively reduced the reagent cost and operating cost of the acid water treatment station, and the comprehensive cost was reduced by more than 30%. In addition, a pH meter can be set in the mine in the acid wastewater in-situ pretreatment system, and the floating device can be controlled by the pH meter. When the pH rises to a certain point, the floating device controls the pipeline to add to other points, which can further reduce the cost of using the system.

Claims

1. An in-situ pretreatment system for acidic wastewater from an open-pit mine, characterized by: The invention comprises a dissolving tank (1) and a pumping tank (2). An overflow plate (7) is arranged between the dissolving tank (1) and the pumping tank (2). A grid-shaped aeration pipeline (6) is arranged in the dissolving tank (1). A pump trough (3) is arranged at the bottom of the pumping tank (2). A slurry pump (8) is installed in the pump trough (3). The outlet of the slurry pump (8) is connected to a conveying pipeline (9). A floating boat (12) is arranged in an open-pit mine (4). The floating boat (12) is connected to a dosing pipeline (11) with dosing holes evenly arranged on the surface. The outlet of the conveying pipeline (9) is connected to the inlet of the dosing pipeline (11) through a metal hose (10).

2. The in-situ pretreatment system for acidic wastewater from an open-pit mine according to claim 1, characterized in that: The dissolving tank (1) and the pumping tank (2) are combined to form a reaction tank, and the reaction tank is set with a slope of 1 to 2% from front to back.

3. The in-situ pretreatment system for acidic wastewater from an open-pit mine according to claim 1, characterized in that: A high-pressure water gun nozzle (5) is installed on the wall of the dissolution tank (1), and the water inlet of the high-pressure water gun nozzle (5) is connected to an external water source.

4. The in-situ pretreatment system for acidic wastewater from an open-pit mine according to claim 1, characterized in that: It also contains a submersible mixer (13), which is installed in the open pit (4).

5. An in-situ pretreatment system for acidic wastewater from an open-pit mine as claimed in claim 1, 2, 3 or 4, characterized in that: A driving device capable of driving the dosing pipeline (11) to move on the water surface of the open-pit mine (4) is installed on the floating boat (12).

6. The in-situ pretreatment system for acidic wastewater from an open-pit mine according to claim 5, characterized in that: The grid-shaped aeration pipeline (6) is connected to an external air compressor via a pipeline.

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