High-efficiency heavy metal removal system for copper smelting waste acid wastewater

Abstract

The utility model relates to the technical field of removal of heavy metals from acid wastewater, and provides a high-efficiency heavy metal removal system for copper smelting waste acid wastewater, which is used for removing heavy metal ions from sewage and comprises a regulating reservoir, the regulating reservoir is used for balancing the quality of the sewage and is provided with a first water outlet, and a vulcanization reactor is used for removing the heavy metal ions from the sewage through vulcanization reaction; the vulcanization reactor comprises a reaction tank, the reaction tank is provided with a first water inlet, the first water outlet is communicated with the first water inlet, sewage enters the reaction tank through the first water inlet, the stirrer is rotationally arranged in the reaction tank, and the water distributor is arranged at the end, away from the stirrer, of the reaction tank; according to the technical scheme, the problems that in the prior art, the metal ion treatment cost of waste acid wastewater is high, and waste salt is generated are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of heavy metal removal from acidic wastewater, and specifically, to a system for efficiently removing heavy metals from copper smelting contaminated acidic wastewater. Background Art

[0002] High-temperature smelting flue gas enters the sulfuric acid purification system for purification treatment, and contacts with dilute acid countercurrently and collides violently in the high-efficiency scrubber to form a liquid film foam area. In the foam area, most of the dust, As 2 O 3 , heavy metals and other impurities are intercepted by the liquid film and collected into the purified circulating dilute acid. When the content of As 2 O 3 in the dilute acid reaches saturation, it is easy to precipitate from the dilute acid. Once the As 2 O 3 crystal precipitates and deposits on the surface of the equipment, it will cause problems such as a decrease in the heat transfer coefficient and pipeline blockage, thus affecting normal production. To ensure the normal operation of the equipment, the arsenic content in the dilute acid must be strictly controlled. Therefore, a certain amount of dilute acid will be continuously discharged, which is the main source of contaminated acid. This part of the contaminated acid has a high arsenic content and is difficult to utilize, and must be treated.

[0003] The contaminated acidic wastewater discharged from the sulfuric acid production process contains about 1-8% of H 2 SO 4 , and also contains heavy metals such as As and Cu. Therefore, a suitable treatment process must be adopted to avoid environmental pollution caused by wastewater discharge.

[0004] Common methods for treating contaminated acidic wastewater include precipitation method, ion exchange adsorption method, extraction method, electrodialysis method, oxidation method, electrocatalysis method, etc. These methods often add a large amount of chemicals, resulting in an increase in the overall wastewater treatment cost. At the same time, the removal effect of heavy metal ions is not good, and it is easy to cause fouling and paralysis of the backend system, affecting the process of wastewater treatment. At the same time, the traditional method of removing heavy metals by sulfidation is prone to the generation of waste salts, which requires additional treatment and increases the cost.

[0005] Therefore, developing a method that can efficiently remove heavy metals is an urgent problem to be solved at present, which can ultimately enable the sustainable development of the entire copper smelting industry. Summary of the Utility Model

[0006] The utility model provides a system for efficiently removing heavy metals from copper smelting contaminated acidic wastewater, which solves the problems of high cost of treating metal ions in contaminated acidic wastewater and generation of waste salts in related technologies.

[0007] The technical solution of the utility model is as follows:

[0008] A system for efficiently removing heavy metals from copper smelting contaminated acidic wastewater, used for removing heavy metal ions from sewage, includes:

[0009] Equalization tank, the equalization tank is used to balance the quality of sewage, and the equalization tank has a first drain outlet.

[0010] Sulfidation reactor, the sulfidation reactor removes heavy metal ions in sewage through sulfidation reaction, and the sulfidation reactor includes:

[0011] Reaction tank, the reaction tank has a first water inlet, the first drain outlet is communicated with the first water inlet, and the sewage enters the reaction tank through the first water inlet.

[0012] Agitator, the agitator is rotatably arranged in the reaction tank.

[0013] Water distributor, the water distributor is arranged at one end of the reaction tank away from the agitator.

[0014] Optionally, the reaction tank further has a second drain outlet, and further includes a gypsum reactor. The gypsum reactor has a second water inlet, the second water inlet is communicated with the second drain outlet, and the gypsum reactor is used to remove fluoride ions and sulfate radicals in sewage.

[0015] Optionally, the gypsum reactor has a third drain outlet, and further includes a gypsum thickener. The gypsum thickener has a third water inlet, the third drain outlet is communicated with the third water inlet, and the gypsum thickener is used to precipitate impurities in sewage.

[0016] Optionally, the gypsum thickener has a fourth drain outlet, and further includes a chemical reaction tank. The chemical reaction tank has a fourth water inlet, the fourth water inlet is communicated with the fourth drain outlet, and the chemical reaction tank is used to remove Ca ions in water.

[0017] Optionally, the gypsum thickener has a fifth drain outlet, and further includes a filtration system. The filtration system has a fifth water inlet, the fifth water inlet is communicated with the fifth drain outlet, and the filtration system is used to remove sewage suspended solids and reduce turbidity.

[0018] Optionally, the filtration system has a sixth drain outlet, and further includes a resin tank. The resin tank has a sixth water inlet, the sixth water inlet is communicated with the sixth drain outlet, and the resin tank is used to reduce the hardness of water.

[0019] Optionally, the resin tank has a seventh drain outlet, and further includes a reverse osmosis system. The reverse osmosis system has a seventh water inlet, the seventh water inlet is communicated with the seventh drain outlet, and the reverse osmosis system is used to concentrate sewage.

[0020] Optionally, the reverse osmosis system has an eighth drain outlet, and further includes an evaporation crystallization device. The evaporation crystallization device has an eighth water inlet, and the eighth water inlet is communicated with the eighth drain outlet. The evaporation crystallization device is used for performing evaporation crystallization treatment on sewage.

[0021] The working principle and beneficial effects of the present utility model are as follows:

[0022] In the present utility model, in order to solve the problems of high cost of treating metal ions in waste acid wastewater and generation of waste salts in related technologies, the sewage is poured into the adjustment tank. The designed residence time of the adjustment tank is 1-2 hours. The sufficient residence time is sufficient to balance the change of the upstream sewage flow rate, ensure the relatively stable influent flow rate of the downstream treatment facilities, reduce the fluctuation of the treatment facility load, and the suspended solids and part of the organic matter in the sewage can precipitate, thereby improving the water quality and reducing the load of the subsequent treatment unit. The sewage in the adjustment tank is discharged through the first drain outlet. The first drain outlet is communicated with the first water inlet. The sewage enters the reaction tank of the sulfidation reactor from the first water inlet. After the incoming water and hydrogen sulfide gas are evenly mixed through the water distributor at the top of the reaction tank, the sewage is stirred by the stirrer to make the solution react with the heavy metals in the wastewater, which can reduce the escape of hydrogen sulfide gas, reduce the treatment cost, realize the removal of heavy metals and arsenic (mainly Cu, As), ensure that the arsenic content in the effluent is ≤1 mg / L and the copper content is ≤0.1 mg / L, and realize the removal rate of heavy metals ≥99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above characteristics, technical features, advantages and their implementation manners of the present utility model will be further described below in a clear and easy-to-understand manner in combination with the drawings in the preferred embodiments.

[0024] Figure 1 is a flow chart of the present utility model;

[0025] Figure 2 is a schematic structural diagram of the sulfidation reactor of the present utility model.

[0026] In the figure: 1. Adjustment tank, 2. Sulfidation reactor, 201. Reaction tank, 202. Stirrer, 203. Water distributor, 3. Gypsum reactor, 4. Gypsum thickener, 5. Chemical reaction tank, 6. Filtration system, 7. Resin tank, 8. Reverse osmosis system, 9. Evaporation crystallization device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the specific embodiments of the present utility model will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts, and other embodiments can also be obtained.

[0028] To simplify the drawings, only the parts related to the utility model are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, to simplify the drawings and facilitate understanding, for components with the same structure or function in some figures, only one of them is schematically shown, or only one of them is labeled. In this article, "one" not only means "only this one", but also can mean "more than one" situation, and "several" includes "two" and "more than two".

[0029] In this article, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0030] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0031] Referring to Figures 1 to 2 , which is the first embodiment of the present utility model, a high-efficiency heavy metal removal system for copper smelting waste acid wastewater is proposed for removing heavy metal ions from sewage, including an adjustment tank 1 for balancing the water quality of sewage. The adjustment tank 1 has a first drain port. The sulfidation reactor 2 removes heavy metal ions from sewage through a sulfidation reaction. The sulfidation reactor 2 includes a reaction tank 201, and the reaction tank 201 has a first water inlet. The first drain port and the first water inlet are connected. The sewage enters the reaction tank 201 through the first water inlet. The agitator 202 is rotatably arranged in the reaction tank 201, and the water distributor 203 is arranged at one end of the reaction tank 201 away from the agitator 202.

[0032] In this utility model, to solve the problems of high cost in treating metal ions in acid waste water and generation of waste salts in related technologies, the sewage is poured into the regulation tank 1. The designed residence time of the regulation tank 1 is 1 - 2 hours. The sufficient residence time can balance the change of the upstream sewage flow rate, ensure the relatively stable influent flow rate of the downstream treatment facilities, reduce the fluctuation of the treatment facility load. The suspended solids and some organic matters in the sewage can precipitate, thereby improving the water quality and reducing the load of the subsequent treatment units. The sewage in the regulation tank 1 is discharged through the first drain outlet. The first drain outlet is communicated with the first inlet. The sewage enters the reaction tank 201 of the sulfidation reactor 2 from the first inlet. After the influent water and hydrogen sulfide gas are evenly mixed through the water distributor 203 at the top of the reaction tank 201, the sewage is stirred by the stirrer 202 to make its solution react with the heavy metals in the waste water, which can reduce the escape of hydrogen sulfide gas, reduce the treatment cost, realize the removal of heavy metals and arsenic (mainly Cu and As), ensure that the arsenic content in the effluent is ≤ 1 mg / L and the copper content is ≤ 0.1 mg / L, and realize the removal rate of heavy metals ≥ 99%.

[0033] Furthermore, the reaction tank 201 also has a second drain outlet, and further includes a gypsum reactor 3. The gypsum reactor 3 has a second inlet. The second inlet is communicated with the second drain outlet. The gypsum reactor 3 is used to remove fluoride ions and sulfate radicals in the sewage.

[0034] In this embodiment, the second drain outlet of the reaction tank 201 is communicated with the second inlet of the gypsum reactor 3. The sulfidation reactor 2 discharges the sewage from the second drain outlet and enters the gypsum reactor 3 from the second inlet. In the gypsum reactor 3, by adding lime, the fluoride ions and sulfate radicals in the waste water are removed, realizing the removal rate of fluoride ions ≥ 99%, and partially removing the sulfate radicals to meet the influent conditions of the backend system.

[0035] Furthermore, the gypsum reactor 3 has a third drain outlet, and further includes a gypsum thickener 4. The gypsum thickener 4 has a third inlet. The third drain outlet is communicated with the third inlet. The gypsum thickener 4 is used to precipitate the impurities in the sewage.

[0036] In this embodiment, the third drain outlet of the gypsum reactor 3 is communicated with the third inlet of the gypsum thickener 4. The gypsum reactor 3 discharges the sewage from the third drain outlet and enters the gypsum thickener 4 from the third inlet. The gypsum thickener 4 can separate the water in the gypsum slurry from the gypsum reactor 3, precipitate the impurities, and form a precipitation layer and supernatant liquid.

[0037] Furthermore, the gypsum thickener 4 has a fourth drain outlet, and further includes a chemical reaction tank 5. The chemical reaction tank 5 has a fourth inlet. The fourth inlet is communicated with the fourth drain outlet. The chemical reaction tank 5 is used to remove Ca ions in the water.

[0038] In this embodiment, the fourth drain outlet of the gypsum thickener 4 is connected to the fourth inlet of the chemical reaction tank 5. The gypsum thickener 4 discharges the sewage from the fourth drain outlet and enters the chemical reaction tank 5 from the fourth inlet. CO 2 gas is introduced into the chemical reaction tank 5 to generate CaCO 3 precipitate with Ca ions in the water, reducing the hardness of the sewage and ensuring that the hardness of the effluent is ≤ 50 mg / L.

[0039] Furthermore, the gypsum thickener 4 has a fifth drain outlet, and a filtration system 6 is further included. The filtration system 6 has a fifth inlet, and the fifth inlet is connected to the fifth drain outlet. The filtration system 6 is used to remove suspended solids in the sewage and reduce turbidity.

[0040] In this embodiment, the fifth drain outlet of the chemical reaction tank 5 is connected to the fifth inlet of the filtration system 6. The chemical reaction tank 5 discharges the sewage from the fifth drain outlet and enters the filtration system 6 from the fifth inlet. The filtration system 6 removes suspended solids and reduces turbidity, ensuring that the turbidity of the effluent from the ultrafiltration device is ≤ 0.1 NTU and the SDI is ≤ 3.

[0041] Furthermore, the filtration system 6 has a sixth drain outlet, and a resin tank 7 is further included. The resin tank 7 has a sixth inlet, and the sixth inlet is connected to the sixth drain outlet. The resin tank 7 is used to reduce the hardness of water.

[0042] In this embodiment, the sixth drain outlet of the filtration system 6 is connected to the sixth inlet of the resin tank 7. The filtration system 6 discharges the sewage from the sixth drain outlet and enters the resin tank 7 from the sixth inlet. The resin softening tank is filled with chelating resin, which has advantages such as large adsorption capacity and good mechanical properties, ensuring that the hardness of the effluent is ≤ 0.03 mmol / L.

[0043] Furthermore, the resin tank 7 has a seventh drain outlet, and a reverse osmosis system 8 is further included. The reverse osmosis system 8 has a seventh inlet, and the seventh inlet is connected to the seventh drain outlet. The reverse osmosis system 8 is used to concentrate the sewage.

[0044] In this embodiment, the seventh drain outlet of the resin tank 7 is connected to the seventh inlet of the reverse osmosis system 8. The resin tank 7 discharges the sewage from the seventh drain outlet and enters the reverse osmosis system 8 from the seventh inlet. The sewage in the resin tank 7 enters the reverse osmosis system 8 for multi-stage concentration. The reverse osmosis system 8 adopts a two-stage design. The first-stage reverse osmosis can concentrate the TDS to ≥ 30000 mg / L, and the second-stage reverse osmosis can concentrate the TDS to ≥ 100000 mg / L. The design flux of the first-stage reverse osmosis is: 13 - 15 LMH, and the design flux of the second-stage reverse osmosis is: 12 - 13 LMH.

[0045] Furthermore, the reverse osmosis system 8 has an eighth drain port, and further includes an evaporation crystallization device 9. The evaporation crystallization device 9 has an eighth water inlet, and the eighth water inlet is communicated with the eighth drain port. The evaporation crystallization device 9 is used for performing evaporation crystallization treatment on sewage.

[0046] In this embodiment, the eighth drain port of the reverse osmosis system 8 is communicated with the eighth water inlet of the evaporation crystallization device 9. The reverse osmosis system 8 discharges sewage from the eighth drain port and enters the evaporation crystallization device 9 from the eighth water inlet to perform evaporation treatment on the reverse osmosis concentrated water. The sodium sulfate crystal salt produced by the evaporation crystallization device 9 can meet the requirements of Class III Grade A in "Industrial Anhydrous Sodium Sulfate" (GB / T 6009-2014), and the sodium chloride crystal salt meets the requirements of Grade II of solar industrial salt in "Industrial Salt" (GB / T 5462-2015). The impurity salt rate is ≤25%, the moisture content of the impurity salt is ≤15%, and the potassium chloride content is ≥40%, realizing zero discharge and the recovery of crystal salt.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A system for efficiently removing heavy metals from copper smelting acid wastewater, characterized in that: Used to remove heavy metal ions from sewage, including: A regulating tank (1), the regulating tank (1) is used to balance the quality of sewage, the regulating tank (1) has a first drain outlet, A sulfidation reactor (2), wherein the sulfidation reactor (2) removes heavy metal ions in sewage through a sulfidation reaction, and the sulfidation reactor (2) comprises: A reaction tank (201), wherein the reaction tank (201) has a first water inlet, the first drain port is connected to the first water inlet, and the sewage enters the reaction tank (201) through the first water inlet. A stirrer (202), wherein the stirrer (202) is rotatably disposed in the reaction tank (201), A water distributor (203), wherein the water distributor (203) is arranged at an end of the reaction tank (201) away from the stirrer (202).

2. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 1, characterized in that: The reaction tank (201) further comprises a second drain outlet, and a gypsum reactor (3), wherein the gypsum reactor (3) comprises a second water inlet, wherein the second water inlet is connected to the second drain outlet, and the gypsum reactor (3) is used to remove fluoride ions and sulfate ions in sewage.

3. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 2, characterized in that: The gypsum reactor (3) has a third drain outlet and also comprises a gypsum thickener (4). The gypsum thickener (4) has a third water inlet. The third drain outlet is connected to the third water inlet. The gypsum thickener (4) is used to precipitate impurities in sewage.

4. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 3, characterized in that: The gypsum thickener (4) has a fourth drain outlet, and also comprises a chemical reaction tank (5), wherein the chemical reaction tank (5) has a fourth water inlet, the fourth water inlet is connected to the fourth drain outlet, and the chemical reaction tank (5) is used to remove Ca ions in water.

5. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 4, characterized in that: The gypsum thickener (4) has a fifth drain outlet and also includes a filtering system (6), wherein the filtering system (6) has a fifth water inlet, the fifth water inlet is connected to the fifth drain outlet, and the filtering system (6) is used to remove suspended matter in sewage and reduce turbidity.

6. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 5, characterized in that: The filtration system (6) has a sixth drainage port, and also includes a resin tank (7), wherein the resin tank (7) has a sixth water inlet, the sixth water inlet is connected to the sixth drainage port, and the resin tank (7) is used to reduce the hardness of water.

7. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 6, characterized in that: The resin tank (7) has a seventh drainage port, and further comprises a reverse osmosis system (8), wherein the reverse osmosis system (8) has a seventh water inlet, the seventh water inlet being connected to the seventh drainage port, and the reverse osmosis system (8) is used to concentrate sewage.

8. A system for efficiently removing heavy metals from copper smelting acid wastewater according to claim 7, characterized in that: The reverse osmosis system (8) has an eighth drain outlet, and also includes an evaporation crystallization device (9), wherein the evaporation crystallization device (9) has an eighth water inlet, wherein the eighth water inlet is connected to the eighth drain outlet, and the evaporation crystallization device (9) is used to perform evaporation crystallization treatment on sewage.

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