Mine acid heavy metal wastewater treatment system

Abstract

The utility model relates to a mine acid heavy metal wastewater treatment system which is characterized in that one or more water body collection units are used for collecting clear water and wastewater and guiding the clear water and wastewater to different wastewater collection libraries and clear water collection libraries, and sampling units are arranged at the output ends of the wastewater collection libraries to collect associated data of the wastewater; a wastewater treatment unit arranged between the output end of the wastewater collection reservoir and the output end of the clear water collection reservoir in a matched manner is driven to configure reactants for wastewater treatment, the reactants act on the wastewater, the treated wastewater and reaction products of the wastewater are settled in a settling pond, and the sampling unit and the wastewater treatment unit are controlled by a controller to work. According to the utility model, the controller is matched with the sampling unit and the wastewater treatment unit, reactants (carbide slag) are accurately added, the acidic heavy metal wastewater is treated under the condition of reducing a large amount of labor investment, and the topographic features are reasonably utilized, so that the power and equipment investment is further reduced, the cost is convenient to control, and the practicability and rapidity are improved.

Description

Technical Field

[0001] This utility model relates to the technical field of water, wastewater, sewage or sludge treatment, and in particular to a mine acidic heavy metal wastewater treatment system that can adapt to the characteristics of valley terrain. Background Technology

[0002] Waste rock dumps and goafs generated from sulfur-containing metal mining often expose minerals such as pyrite (FeS2) in the ore body to the natural environment. Under the combined action of oxygen, water, and microorganisms, acidic mine wastewater (AMD) is continuously generated. AMD typically has a pH value below 4.0 and contains high concentrations of sulfates and heavy metal ions, such as iron (Fe), manganese (Mn), zinc (Zn), lead (Pb), cadmium (Cd), copper (Cu), and arsenic (As). If not collected and treated, AMD entering the watershed will lead to excessively high concentrations of metal ions in water and soil, which will gradually accumulate, posing a serious threat to the safety of the watershed's aquatic and soil ecosystem and the health of residents, and having a long-term impact on the surface water environment.

[0003] To mitigate the impact of acidic heavy metal wastewater on surface water, long-term treatment of acidic heavy metal wastewater is necessary. In the field of mine acidic wastewater treatment, NaOH or lime is usually used to neutralize the mine acidic wastewater. NaOH is expensive, which leads to high treatment costs. Neutralizing acidic wastewater with lime requires lime slurry manufacturing equipment to convert lime into lime slurry, which is then mixed with the acidic wastewater for reaction. This will result in long-term and large-scale investment of manpower, electricity and material resources. Utility Model Content

[0004] This invention solves the problems existing in the prior art and provides a mine acidic heavy metal wastewater treatment system that adapts to the terrain features of valleys, uses the terrain features to solve the power problem, control the reaction conditions, and utilize the reactants as resources, thereby solving the above-mentioned problems of cost input and long-term stable operation and maintenance.

[0005] The technical solution adopted in this utility model is a treatment system for acidic heavy metal wastewater from mines, the system comprising:

[0006] One or more water collection units are used to collect clean water and wastewater and direct them to different wastewater collection reservoirs and clean water collection reservoirs;

[0007] A sampling unit is located at the output end of the wastewater collection reservoir to collect related data of the wastewater.

[0008] A wastewater treatment unit is located between the output end of the wastewater collection tank and the output end of the clean water collection tank. It is used to prepare the reactants for wastewater treatment and act on the wastewater.

[0009] A sedimentation tank is installed after the wastewater treatment unit to settle the treated wastewater and its reaction products.

[0010] A controller is provided to work in conjunction with the sampling unit and the wastewater treatment unit.

[0011] Preferably, the output end of the water collection unit is higher than the input ends of the wastewater collection reservoir and the clean water collection reservoir.

[0012] Preferably, the sampling unit includes a flow weir located at the output end of the wastewater collection reservoir, and a first water quality sensor and a level gauge are provided in conjunction with the flow weir; the first water quality sensor and the level gauge are configured in conjunction with the controller.

[0013] Preferably, the wastewater treatment unit includes a silo for placing reactants, a water inlet pipe between the silo and the clear water collection tank, a gravity flow channel connecting the silo and the flow weir, and the gravity flow channel and the flow weir are connected to the sedimentation tank.

[0014] Preferably, the gravity flow channel and the flow weir are connected to one end of the reaction culvert, and the other end of the reaction culvert is connected to the sedimentation tank space; the end of the reaction culvert connected to the gravity flow channel and the flow weir is higher than the other end of the reaction culvert connected to the sedimentation tank.

[0015] Preferably, the gravity flow channel and the reaction culvert include at least one corner in their transport direction.

[0016] Preferably, the fluid volume that can pass through the reaction culvert per unit time is greater than the fluid volume that can pass through the flow weir per unit time.

[0017] Preferably, the cross-sectional area of ​​the reaction culvert is greater than 1.5 times the cross-sectional area of ​​the maximum inflow; the maximum flow rate of the flow weir is 1.5 times the maximum inflow.

[0018] Preferably, a second water quality sensor is provided in conjunction with the sedimentation tank, and the second water quality sensor is configured in conjunction with the controller.

[0019] Preferably, the ratio of the volume of the sedimentation tank to the volume of the wastewater collection reservoir is greater than 2:1.

[0020] This utility model relates to a mine acidic heavy metal wastewater treatment system, which uses one or more water collection units to collect clean water and wastewater and guide them to different wastewater collection reservoirs and clean water collection reservoirs. A sampling unit is set at the output end of the wastewater collection reservoir to collect relevant data of the wastewater. Based on this data, a wastewater treatment unit located between the output ends of the wastewater collection reservoir and the clean water collection reservoir is activated to prepare wastewater treatment reactants and act on the wastewater. The wastewater and its reaction products are then settled in a subsequent sedimentation tank. A controller controls the operation of the sampling unit and the wastewater treatment unit.

[0021] The beneficial effects of this utility model are that, through the cooperation between the controller, the sampling unit, and the wastewater treatment unit, the reactant (carbide slag) can be accurately added, thereby reducing a large amount of manual labor and achieving the treatment of acidic heavy metal wastewater. Furthermore, by making reasonable use of the terrain features, the power and equipment investment can be further reduced, making it easier to control costs and increasing practicality and speed. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model, where the dashed lines represent electrical connections. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0024] This utility model relates to a system for treating acidic heavy metal wastewater from mines, the system comprising:

[0025] One or more water collection units 1 are used to collect clean water and wastewater and guide them to different wastewater collection reservoirs 2 and clean water collection reservoirs 3;

[0026] A sampling unit is located at the output end of wastewater collection reservoir 2 to collect associated data of wastewater.

[0027] A wastewater treatment unit is located between the output end of wastewater collection tank 2 and the output end of clean water collection tank 3, and is used to prepare wastewater treatment reactants and act on the wastewater.

[0028] A sedimentation tank 4 is installed after the wastewater treatment unit to settle the treated wastewater and its reaction products.

[0029] A controller 5 is provided to work in conjunction with the sampling unit and the wastewater treatment unit.

[0030] This invention is applied to valley areas of mines with elevation differences that continuously generate acidic wastewater. It can make full use of the elevation differences but does not depend on the shape of the mountain itself.

[0031] In the specific implementation process, a water collection unit 1 is designed and constructed on the surface of the goaf located in the upper reaches of the valley. An interception channel system is constructed on the upstream slope of the surface water collection surface corresponding to the goaf. On the one hand, it prevents surface precipitation from infiltrating into the goaf. On the other hand, it diverts the surface water runoff formed during the precipitation process into the channel and introduces it into the clear water collection reservoir 3 from the clear water diversion channel 11. The acidic wastewater generated from the acidic wastewater inflow points at the middle section of each goaf and the leachate collection points at the waste rock dump in the valley flows into the acidic water diversion channel 12 and is then collected in the wastewater collection reservoir 2.

[0032] In practice, the output end of the water collection unit 1 is higher than the input ends of the wastewater collection reservoir 2 and the clean water collection reservoir 3. That is, the wastewater collection reservoir 2 and the clean water collection reservoir 3 are generally built downstream to collect acidic wastewater and clean water from upstream, respectively, and they are used interchangeably to provide clean water sources, regulate the quality of acidic water, buffer the flow rate, and ensure the stability of the treatment effect of acidic heavy metal wastewater.

[0033] For the collected acidic wastewater, water quality and quantity monitoring is required first. Specifically, the sampling unit includes a flow weir 6 located at the output end of the wastewater collection reservoir 2, and a first water quality sensor 7 and a level gauge (not shown in the figure) are provided in conjunction with the flow weir 6; the first water quality sensor 7 and the level gauge are configured in conjunction with the controller 5.

[0034] Among them, water quality monitoring uploads monitoring data to controller 5 through the first water quality sensor 7, and water volume monitoring uploads real-time water level to controller 5 through level gauge (water level sensor). The real-time water level is converted into the weir depth h of the flow weir 6, and then the corresponding flow rate Q is calculated by the flow calculation formula. The flow calculation formula needs to be determined according to the shape and model of the flow weir 6. Generally speaking, the flow weir 6 is classified according to its shape, including but not limited to rectangular weir, triangular weir, trapezoidal weir, and Parshall weir. Its model is determined according to the maximum inflow.

[0035] In this invention, the controller interacts with the sampling unit and the wastewater treatment unit via electrical connection (or signal connection). This is something that those skilled in the art can easily understand, and they can set it up according to their needs.

[0036] The wastewater treatment unit includes a silo 8 for holding reactants. A water inlet pipe 9 connects the silo 8 and the clear water collection reservoir 3. The silo 8 and the flow weir 6 are connected by a gravity flow channel 10, which in turn connects to the sedimentation tank 4. The reactants in the silo 8 include, but are not limited to, one or more of carbide slag, sodium hydroxide, and limestone. Conventional alkaline materials are generally used for acid-base neutralization reactions. Carbide slag is preferred because its fine particles allow it to react fully as it migrates downstream in the reaction culvert 13 under gravity. Based on water quality and quantity monitoring data, the theoretical consumption of reactants can be calculated. This theoretical consumption is then multiplied by a reactant addition safety factor to obtain the initial actual addition amount, which is then added through a wastewater treatment unit. Specifically, the water flow is controlled via a water inlet pipe 9, typically using a valve to ensure that the reactants carried by the water are approximately equal to the initial actual addition amount. The reactants, after passing through a gravity flow channel 10, mix with the acidic wastewater at the outlet of the flow weir 6, initiating the reaction. A reaction culvert 13 is constructed, with the gravity flow channel 10 and the flow weir 6 connected to one end of the reaction culvert 13. The other end of the reaction culvert 13 is spatially connected to the sedimentation tank 4. This means that after the reactants are mixed with clean water, they react with the acidic wastewater within the reaction culvert 13. The end of the reaction culvert 13 connected to the gravity flow channel 10 and the flow weir 6 is higher than the other end connected to the sedimentation tank 4, allowing the reactants to continue reacting downwards under gravity.

[0037] The sedimentation tank 4 is equipped with a second water quality sensor 14, which is set up in conjunction with the controller 5 to simultaneously monitor the pH value of the effluent online in real time at the end of the reaction culvert 13. Based on the results of the indoor test conducted in advance, by maintaining the pH value > 8.5, it is ensured that most metals can be precipitated through the neutralization reaction. If the pH value fails to meet the standard, the amount of reactant added is increased in time until the standard is met.

[0038] In this invention, clean water from the clean water collection tank 3 is diverted to the silo 8. The horizontal height of the output end of the clean water collection tank 3 is much higher than that of the silo 8, so the water can flow to the silo 8 by gravity, flushing and carrying the reactants into the gravity flow channel 10. The greater the water flow, the more reactants are carried. The water flow is controlled by the faucet switch, thereby controlling the amount of reactants added.

[0039] The gravity flow channel 10 and the reaction culvert 13 include at least one corner in their conveying direction.

[0040] The main function of the reaction culvert 13 is to allow the reactants to fully mix and react with the acidic heavy metal wastewater. In this embodiment, the entire reaction culvert 13 is about 1400m long. After the reactants enter the reaction culvert 13 through the gravity flow channel 10, they have sufficient time to mix and react with the acidic heavy metal wastewater, thereby reducing the pH value of the acidic wastewater and causing the heavy metals to precipitate. In order to prolong the reaction time, the reaction culvert 13 is designed to include at least one bend. Similarly, in order to better reduce the impact intensity, the gravity flow channel 10 is designed to include at least one bend.

[0041] The fluid volume that can pass through the reaction culvert 13 per unit time is greater than the fluid volume that can pass through the flow weir 6 per unit time.

[0042] The cross-sectional area of ​​the reaction culvert 13 is more than 1.5 times the cross-sectional area of ​​the maximum inflow; the maximum flow rate of the flow weir 6 is 1.5 times the maximum inflow.

[0043] The volume ratio of the sedimentation tank 4 to the wastewater collection reservoir 2 is greater than 2:1.

[0044] Specifically, the volume of sedimentation tank 4 needs to be determined based on the maximum inflow, generally to meet at least 12 hours of maximum inflow, so as to ensure that the acidic heavy metal wastewater after neutralization reaction through reaction culvert 13 has sufficient time to continue to react and settle. The volume of acidic heavy metal wastewater collection reservoir 2 needs to be determined based on the maximum inflow, generally to meet at least 6 hours of maximum inflow, so that management personnel have enough time to adjust the dosage of reactants for acidic heavy metal wastewater treatment.

[0045] The following is a specific embodiment of this utility model;

[0046] (1) Collection of acidic heavy metal wastewater: First, construct an acidic heavy metal wastewater collection reservoir 2 to collect acidic heavy metal wastewater. The volume of the wastewater collection reservoir 2 should generally meet the maximum inflow for 6 hours. In this embodiment, the maximum inflow is 400 m³ / h, and the volume of the wastewater collection reservoir 2 is set to 2400 m³, with dimensions of 20 m × 20 m × 6 m.

[0047] (2) Water quality and quantity monitoring: A flow weir 6 is set at the tail end of the wastewater collection reservoir 2. This weir is rectangular. A first water quality sensor 7 and a level gauge are set to monitor water quality and water level.

[0048] A rectangular weir is 60cm wide and 60cm high. Its flow rate calculation formula is:

[0049] Q=0.018Bh 3 / 2

[0050] Where Q is the flow rate over the weir (L / s). B Width of the weir (cm) hThe depth of the water flowing over the weir (cm) is 0.018, and the flow coefficient is 0.018.

[0051] The real-time water level is uploaded to controller 5, and the bottom elevation of the rectangular weir is set to the initial elevation h0. The real-time water level (H) and the initial elevation h0 are the water depths of the flow weir 6. h Then, the corresponding flow rate (Q) is calculated using the above flow rate calculation formula. Taking a weir depth h of 20cm as an example, the weir flow rate is 96.60L / s, which is 347.75m³ / h.

[0052] Water quality monitoring mainly monitors pH value and excessive heavy metals (Zn). After being uploaded to controller 5, the pH value is 2 and the Zn concentration is 550 mg / L.

[0053] (3) Addition of reactants

[0054] Let the safety factor for reactant addition be 1.5;

[0055] According to the reaction formula

[0056] Ca(OH)₂ + 2 H⁺ + → Ca 2+ +2 H2O

[0057] The calculation shows that 569.2g of carbide slag is required to neutralize 1m³ of acidic heavy metal wastewater with an initial pH of 2 using carbide slag containing 65% Ca(OH)2.

[0058] According to the reaction formula

[0059] Zn 2+ +2 Ca(OH)2→Zn(OH)2+2Ca 2+

[0060] The calculation shows that 1926.6g of calcium carbide slag is required to precipitate Zn heavy metals from 1m³ of acidic heavy metal wastewater.

[0061] Theoretical calculations show that acid neutralization and precipitation of heavy metal Zn consumed a total of 2495.8g of carbide slag.

[0062] Adjusting the pH of the water to around 8.0 requires a relatively small amount of calcium carbide slag. The amount of calcium carbide slag consumed by impurities in the water is difficult to calculate theoretically. The actual dosage is based on the amount of calcium carbide slag consumed by acid neutralization and heavy metal Zn precipitation (2495.8g), multiplied by a reactant addition safety factor of 1.5, resulting in an initial actual dosage of 3743.7g. At this point, the water volume is adjusted so that the reactants carried by the water are approximately equal to the initial actual dosage. The reactants enter the reaction culvert 13 through the gravity flow channel 10 and mix with the acidic heavy metal wastewater to react. At the end of the reaction culvert 13, the water quality is monitored by a second water quality sensor 14. If the water quality fails to meet the standard, the amount of reactant added is increased in time until the standard is met.

[0063] (4) Reactants are mixed with acidic heavy metal wastewater for reaction.

[0064] The reactants enter the reaction culvert 13 through the gravity flow channel 10. The reaction culvert 13 has a radius of about 0.5m and an area of ​​about 0.80㎡, which can meet 1.5 times the maximum inflow without overflowing. The reaction culvert 13 is about 1400m long, which gives the reactants enough time to react with the acidic heavy metal wastewater.

[0065] Acidic heavy metal wastewater enters sedimentation tank 4 after passing through reaction culvert 13, where it further reacts with the reactants. The volume of sedimentation tank 4 meets the maximum inflow rate for 12 hours. In this embodiment, the maximum inflow rate is 400 m³ / h, and the volume of sedimentation tank 4 is set to 4800 m³, with dimensions of 40 m × 40 m × 3 m.

[0066] After further reaction in sedimentation tank 4, the acidic heavy metal wastewater is discharged after meeting the standards.

[0067] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0068] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A system for treating acidic heavy metal wastewater from mines, characterized in that: The system includes: One or more water collection units are used to collect clean water and wastewater and direct them to different wastewater collection reservoirs and clean water collection reservoirs; A sampling unit is located at the output end of the wastewater collection reservoir to collect related data of the wastewater. A wastewater treatment unit is located between the output end of the wastewater collection tank and the output end of the clean water collection tank. It is used to prepare the reactants for wastewater treatment and act on the wastewater. A sedimentation tank is installed after the wastewater treatment unit to settle the treated wastewater and its reaction products. A controller is provided to work in conjunction with the sampling unit and the wastewater treatment unit.

2. The mine acidic heavy metal wastewater treatment system according to claim 1, characterized in that: The output of the water collection unit is higher than the input of the wastewater collection reservoir and the clean water collection reservoir.

3. The mine acidic heavy metal wastewater treatment system according to claim 1, characterized in that: The sampling unit includes a flow weir located at the output end of the wastewater collection reservoir, and a first water quality sensor and a level gauge are provided in conjunction with the flow weir; the first water quality sensor and the level gauge are configured in conjunction with the controller.

4. The mine acidic heavy metal wastewater treatment system according to claim 3, characterized in that: The wastewater treatment unit includes a silo for holding reactants, a water inlet pipe between the silo and the clear water collection tank, and a gravity flow channel connecting the silo and the flow weir. The gravity flow channel and the flow weir are connected to the sedimentation tank.

5. The mine acidic heavy metal wastewater treatment system according to claim 4, characterized in that: The gravity flow channel and the flow weir are connected to one end of the reaction culvert, and the other end of the reaction culvert is connected to the sedimentation tank space; the end of the reaction culvert connected to the gravity flow channel and the flow weir is higher than the other end of the reaction culvert connected to the sedimentation tank.

6. The mine acidic heavy metal wastewater treatment system according to claim 5, characterized in that: The gravity-flow channel and reaction culvert include at least one corner in their transport direction.

7. The mine acidic heavy metal wastewater treatment system according to claim 5, characterized in that: The fluid volume that can pass through the reaction culvert per unit time is greater than the fluid volume that can pass through the flow weir per unit time.

8. The mine acidic heavy metal wastewater treatment system according to claim 7, characterized in that: The cross-sectional area of ​​the reaction culvert is greater than 1.5 times the cross-sectional area of ​​the maximum inflow; the maximum flow rate of the flow weir is 1.5 times the maximum inflow.

9. The mine acidic heavy metal wastewater treatment system according to claim 1, characterized in that: A second water quality sensor is provided in conjunction with the sedimentation tank, and the second water quality sensor is configured in conjunction with the controller.

10. A mine acidic heavy metal wastewater treatment system according to claim 1, characterized in that: The volume ratio of the sedimentation tank to the wastewater collection reservoir is greater than 2:1.

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