System and method for separating Cu and As from industrial waste liquid

Abstract

The present invention provides a system and method for separating Cu and As in industrial waste liquid. The system includes a primary sulfidation device, a final sulfidation device, and at least one intermediate sulfidation device, which are connected in series in sequence. The intermediate sulfidation device includes a pulping tank. The feeding end of the pulping tank is respectively communicated with the output end of the sulfide precipitate of the intermediate sulfidation device and the output end of the original liquid of the industrial waste liquid, and the output end of the pulping tank is communicated with the previous-stage sulfidation device or the primary sulfidation device of the intermediate sulfidation device. Through this application, the Cu ions contained in the waste liquid of the sulfidation reaction in the primary sulfidation device and the intermediate sulfidation device are almost completely reacted to form a sulfide precipitate mainly composed of CuS precipitate, while the waste liquid of the sulfidation reaction entering the final sulfidation device produces a final sulfide precipitate mainly composed of As2S3, effectively realizing the separation of Cu ions and As ions.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial waste liquid treatment, and particularly relates to a system and method for separating Cu and As in industrial waste liquid. Background Art

[0002] In many domestic smelting and chemical production processes, waste liquid containing various metal ions is generated. When treating this waste liquid, it is necessary to remove the metal ions in the waste liquid so that the waste liquid can meet the standards before being discharged or reused. The sulfide method is usually selected to remove the metal ions in the waste liquid, that is, by adding a sulfiding agent to react with the metal ions in the waste liquid to form sulfide precipitates, and then through liquid-solid separation, the sulfide precipitates are discarded to achieve the purpose of removing metal ions.

[0003] Usually, the sulfide treatment of waste liquid mostly adopts the one-step sulfide treatment method, that is, all the metal ions that can form sulfide precipitates are reacted to produce sulfide precipitates at one step. In this way, the separation of valuable metal Cu and harmful element As is not achieved, which not only wastes the valuable metal Cu but also increases the content of harmful element As in the sulfide precipitates. In recent years, a small number of enterprises have implemented the two-step sulfide treatment method. Compared with the one-step sulfide treatment method, the separation effect of valuable metal Cu and harmful element As in the waste liquid has been further improved. However, a lot of harmful element As is still brought into the sulfide precipitates containing valuable metals in the secondary sulfide treatment. Similarly, a large amount of valuable metal Cu is also mixed in the sulfide precipitates containing harmful metals, and the effective separation of valuable metal Cu and harmful element As has not been truly achieved, and it still cannot meet the environmental protection requirements of recovering valuable metal Cu and reducing the disposal cost of harmful metal precipitates.

[0004] Therefore, how to effectively separate Cu and As in industrial waste liquid to reduce the content of harmful element As in the sulfide precipitates containing valuable metals after sulfide treatment and the content of valuable metal Cu in the sulfide precipitates containing harmful metals is an urgent problem to be solved. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a system and method for separating Cu and As in industrial waste liquid. By reasonably arranging an intermediate-stage sulfide device between the primary sulfide device and the final sulfide device and adding a pulping tank to the intermediate-stage sulfide device, the content of harmful element As in the sulfide precipitates containing valuable metals after sulfide treatment and the content of valuable metal Cu in the sulfide precipitates containing harmful metals are effectively reduced.

[0006] In a first aspect, the invention provides a system for separating Cu and As from industrial waste liquid. The system includes a primary sulfidation device, a final sulfidation device, and at least one intermediate sulfidation device disposed between the primary sulfidation device and the final sulfidation device. The primary sulfidation device, the intermediate sulfidation device, and the final sulfidation device are connected in series in sequence. The intermediate sulfidation device includes a pulping tank. The feeding end of the pulping tank is respectively communicated with the output end of the sulfide precipitate of the intermediate sulfidation device and the output end of the original solution of the industrial waste liquid, and the output end of the pulping tank is communicated with the previous-stage sulfidation device or the primary sulfidation device of the intermediate sulfidation device.

[0007] In some embodiments, a stirrer for stirring the sulfide precipitate of the intermediate sulfidation device and the original solution of the industrial waste liquid is provided in the pulping tank, so that Cu ions in the original solution react with As2S3 to displace As ions and CuS.

[0008] In some embodiments, the primary sulfidation device, the intermediate sulfidation device, and the final sulfidation device all include a sulfidation reactor and a liquid-solid separation device arranged in sequence along the flowing direction of the industrial waste liquid. The feeding end of the pulping tank is communicated with the output end of the sulfide precipitate of the liquid-solid separation device of the intermediate sulfidation device.

[0009] In some embodiments, a feeding port for adding a sulfiding agent is provided at the feeding end of the sulfidation reactor.

[0010] In a second aspect, the invention provides a method for separating Cu and As from industrial waste liquid, which is applied to the above-mentioned system for separating Cu and As from industrial waste liquid. The method includes:

[0011] The original solution of the industrial waste liquid is sent into the primary sulfidation device through a pipeline for a sulfidation reaction. After the sulfidation reaction is completed, a primary sulfide precipitate and a primary clear liquid are produced through liquid-solid separation treatment.

[0012] The primary clear liquid is sent into the intermediate sulfidation device through a pipeline for a sulfidation reaction. After the sulfidation reaction is completed, an intermediate sulfide precipitate and an intermediate clear liquid are produced through liquid-solid separation treatment. The intermediate sulfide precipitate is sent to the pulping tank through a pipeline segment. At the same time, the pulping tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the previous-stage sulfidation device of the intermediate sulfidation device or the primary sulfidation device through a pipeline, so that the previous-stage sulfidation device produces an intermediate sulfide precipitate mainly composed of CuS precipitate or the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate.

[0013] The intermediate-stage supernatant is sent through a pipeline to the final-stage sulfidation device for a sulfidation reaction. After the sulfidation reaction is completed, liquid-solid separation treatment is carried out to produce a final-stage sulfide precipitate and a final-stage supernatant, so that the final-stage sulfide precipitate mainly composed of As2S3 is produced by the final-stage sulfidation device.

[0014] In some embodiments, the sulfide precipitate of the intermediate-stage sulfidation device and the original solution of the industrial waste liquid are mixed and stirred in the pulping tank, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS.

[0015] In some embodiments, the uniformly stirred intermediate-stage sulfide precipitate and the original solution of the industrial waste liquid in the pulping tank are returned to the upper-stage sulfidation device or the first-stage sulfidation device after the reaction, so as to inhibit the production of As2S3 in the sulfidation reaction of the upper-stage sulfidation device or the first-stage sulfidation device.

[0016] In some embodiments, the first-stage sulfidation device, the intermediate-stage sulfidation device and the final-stage sulfidation device all include a sulfidation reactor and a liquid-solid separation device arranged in sequence along the flowing direction of the industrial waste liquid, and the feeding end of the pulping tank is communicated with the output end of the sulfide precipitate of the liquid-solid separation device.

[0017] In some embodiments, a feeding port for adding a sulfiding agent is provided at the feeding end of the sulfidation reactor.

[0018] In some embodiments, the addition amount of the sulfiding agent is adjusted by the redox potential value in the liquid after the sulfidation reaction in the sulfidation reactor.

[0019] One or more of the above technical solutions in the system and method for separating Cu and As in industrial waste liquid provided by the present invention at least have the following technical effects:

[0020] An intermediate-stage vulcanization device is added between the primary vulcanization device and the final-stage vulcanization device, and a pulping tank is added to the intermediate-stage vulcanization device. The primary solution of the intermediate-stage sulfide precipitate and industrial waste liquid fed into it is stirred in the pulping tank, so that Cu ions and As2S3 in the primary solution react to displace As ions and CuS, and then it is returned to the previous-stage vulcanization device or the primary vulcanization device, effectively improving the CuS produced by the vulcanization reaction in the previous-stage vulcanization device or the primary vulcanization device, reducing the generation of As2S3, so that the intermediate-stage sulfide precipitate mainly composed of CuS precipitate is produced in the previous-stage vulcanization device, or the primary sulfide precipitate mainly composed of CuS precipitate is produced in the primary vulcanization device, while the final-stage sulfide precipitate mainly composed of As2S3 is produced in the final-stage vulcanization device, realizing that almost all the Cu ions in the waste liquid of the vulcanization reaction in the primary vulcanization device and the intermediate-stage vulcanization device react completely, forming a sulfide precipitate mainly composed of CuS precipitate, and most of the As2S3 precipitates produced from the waste liquid of the vulcanization reaction entering the final-stage vulcanization device, forming a final-stage sulfide precipitate mainly composed of As2S3, effectively realizing the separation of Cu ions and As ions in the true sense, improving the utilization rate of valuable metals while reducing the disposal cost of harmful metal precipitates. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Flow chart of the system for separating Cu and As in industrial waste liquid provided in Embodiment 1 of the present invention;

[0023] Figure 2 Flow chart of the method for separating Cu and As in industrial waste liquid provided in Embodiment 1 of the present invention;

[0024] Figure 3 Flow chart of the system for separating Cu and As in industrial waste liquid provided in Embodiment 2 of the present invention;

[0025] Figure 4 Flow chart of the method for separating Cu and As in industrial waste liquid provided in Embodiment 2 of the present invention;

[0026] Figure 5 Flow chart of the system for separating Cu and As in industrial waste liquid provided in Embodiment 3 of the present invention;

[0027] Figure 6 Flow chart of the method for separating Cu and As in industrial waste liquid provided in Embodiment 3 of the present invention.

[0028] Description of the reference numerals in the drawings:

[0029] 10 - Primary vulcanization device, 11 - Primary vulcanization reactor, 12 - Primary liquid-solid separation equipment;

[0030] 20 - Final-stage vulcanization device, 21 - Final-stage vulcanization reactor, 22 - Final-stage liquid-solid separation equipment;

[0031] 30 - First intermediate-stage vulcanization device, 31 - First intermediate-stage vulcanization reactor, 32 - First intermediate-stage liquid-solid separation equipment, 33 - First pulping tank, 331 - First stirrer;

[0032] 40 - Second intermediate-stage vulcanization device, 41 - Second intermediate-stage vulcanization reactor, 42 - Second intermediate-stage liquid-solid separation equipment, 43 - Second pulping tank, 431 - Second stirrer. Detailed implementation manners

[0033] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the embodiments of the present invention, and should not be construed as a limitation of the present invention.

[0034] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0036] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; 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 or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0037] Embodiment 1

[0038] An embodiment of the present invention provides a method for separating Cu and As in industrial waste liquid, which is applied to a system for separating Cu and As in industrial waste liquid. As Figure 1 shown, the system includes a primary sulfidation device 10, a final sulfidation device 20, and a first intermediate sulfidation device 30 disposed between the primary sulfidation device 10 and the final sulfidation device 20. The primary sulfidation device 10, the first intermediate sulfidation device 30, and the final sulfidation device 20 are connected in series in sequence. The first intermediate sulfidation device 30 includes a first pulping tank 31. The feeding end of the first pulping tank 31 is respectively communicated with the output end of the sulfide precipitate of the first intermediate sulfidation device 30 and the output end of the original solution of the industrial waste liquid, and the output end of the first pulping tank 31 is communicated with the primary sulfidation device 10. Specifically, the primary sulfidation device 10, the first intermediate sulfidation device 30, and the final sulfidation device 20 all include a sulfidation reactor and a liquid-solid separation device arranged in sequence along the flowing direction of the industrial waste liquid. The feeding end of the first pulping tank 31 is communicated with the output end of the sulfide precipitate of the first intermediate liquid-solid separation device 32 of the first intermediate sulfidation device 30; wherein, a feeding port for adding a sulfiding agent is opened at the feeding end of the sulfidation reactor.

[0039] In specific practice, first, a large amount of waste acid is produced by the acid purification device for copper smelting flue gas to form the original solution of industrial waste acid (containing valuable metal Cu ions and harmful element As ions). The original solution of the industrial waste liquid is pumped to the primary sulfidation reactor 11 of the primary sulfidation device 10 through a pipeline. At the same time, the sulfiding agent is added through the feeding port of the primary sulfidation reactor 11 to carry out a sulfidation reaction with the original solution. The treated liquid after the sulfidation reaction is pumped to the primary liquid-solid separation device 12 of the primary sulfidation device 10 for solid-liquid separation treatment. The separated primary sulfide precipitate is recovered or sold as a product, and the primary clear liquid is pumped to the first intermediate sulfidation reactor 31 of the first intermediate sulfidation device 30;

[0040] Secondly, the primary supernatant reacts with the sulfiding agent added through the feed inlet of the first intermediate-stage sulfiding reactor 31. The treated liquid after the sulfiding reaction is pumped to the first-stage liquid-solid separation equipment 32 of the first intermediate-stage sulfiding device 30 for solid-liquid separation. The separated first intermediate-stage sulfide precipitate is pumped to the first pulping tank 33, and is mixed and stirred evenly with the original solution of the industrial waste liquid pumped to the first pulping tank 33 through the first stirrer 331, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS, and then are pumped to the primary sulfiding reactor 11 for sulfiding reaction, so that the primary sulfide precipitate inhibits the production of As2S3 in the sulfiding reaction of the primary sulfiding reactor 11, and realizes that the primary sulfide precipitate produced in the sulfiding reaction of the primary sulfiding reactor 11 is mainly CuS precipitate (only containing a small amount of As2S3); while the separated first intermediate-stage supernatant is pumped to the final-stage sulfiding reactor 21 of the final-stage sulfiding device 20;

[0041] Finally, the first intermediate-stage supernatant reacts with the sulfiding agent added through the feed inlet of the final-stage sulfiding reactor 21. The treated liquid after the sulfiding reaction is pumped to the final-stage liquid-solid separation equipment 22 of the final-stage sulfiding device 20 for solid-liquid separation. The separated final-stage sulfide precipitate, which is mainly As2S3 precipitate (only containing a small amount of CuS), is collected for centralized pollutant treatment; while the separated final-stage supernatant can be transported to the next process for utilization.

[0042] It should be noted that in the above specific practice, the addition amount of the sulfiding agent is adjusted by the redox potential value in the liquid after the sulfiding reaction in the sulfiding reactors at each stage.

[0043] As Figure 2 shown, a method for separating Cu and As in industrial waste liquid provided in this embodiment is applied to a system for separating Cu and As in industrial waste liquid. The system includes a primary sulfiding device, a final-stage sulfiding device, and a first intermediate-stage sulfiding device disposed between the primary sulfiding device and the final-stage sulfiding device. The primary sulfiding device, the first intermediate-stage sulfiding device, and the final-stage sulfiding device are connected in series in sequence; the first intermediate-stage sulfiding device includes a first pulping tank. The feed end of the first pulping tank is respectively communicated with the output end of the first intermediate-stage sulfide precipitate of the first intermediate-stage sulfiding device and the output end of the original solution of the industrial waste liquid, and the output end of the first pulping tank is communicated with the primary sulfiding device; the method includes the following steps S101 to S103:

[0044] S101: The original solution of the industrial waste liquid is sent through a pipeline to the primary sulfiding device for sulfiding reaction. After the sulfiding reaction is completed, a primary sulfide precipitate and a primary supernatant are produced through solid-liquid separation treatment;

[0045] S102: Feed the primary supernatant through a pipeline into the first stage of the first intermediate-stage sulfidation device for sulfidation reaction. After the sulfidation reaction is completed, perform liquid-solid separation to produce the first intermediate-stage sulfide precipitate and the first intermediate-stage supernatant. Send the first intermediate-stage sulfide precipitate through a pipeline section to the first slurry tank. At the same time, add the original solution of industrial waste liquid to the first slurry tank through a pipeline for stirring. After stirring evenly, send it through a pipeline to the primary sulfidation device, so that the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate;

[0046] S103: Feed the first intermediate-stage supernatant through a pipeline into the final-stage sulfidation device for sulfidation reaction. After the sulfidation reaction is completed, perform liquid-solid separation to produce the final-stage sulfide precipitate and the final-stage supernatant, so that the final-stage sulfidation device produces the final-stage sulfide precipitate mainly composed of As2S3.

[0047] In summary, through the first slurry tank, stir the first intermediate-stage sulfide precipitate and the original solution of industrial waste liquid fed into it, so that Cu ions in the original solution react with As2S3 to displace As ions and CuS, and then return to the primary sulfidation device, effectively improving the production of CuS in the sulfidation reaction in the primary sulfidation device and reducing the generation of As2S3, so that the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate, while the final-stage sulfidation device produces the final-stage sulfide precipitate mainly composed of As2S3, realizing that almost all Cu ions in the waste liquid of the sulfidation reaction in the primary sulfidation device and the first intermediate-stage sulfidation device react completely, forming a sulfide precipitate mainly composed of CuS precipitate, and most of the As2S3 precipitates produced from the waste liquid of the sulfidation reaction entering the final-stage sulfidation device, forming a final-stage sulfide precipitate mainly composed of As2S3, effectively realizing the separation of Cu ions and As ions in a real sense.

[0048] Example 2

[0049] An embodiment of the present invention provides a method for separating Cu and As in industrial waste liquid, which is applied to a system for separating Cu and As in industrial waste liquid. As Figure 3As shown, the system includes a primary vulcanization device 10, a final vulcanization device 20, a first intermediate vulcanization device 30 and a second intermediate vulcanization device 40 disposed between the primary vulcanization device 10 and the final vulcanization device 20. The primary vulcanization device 10, the first intermediate vulcanization device 30, the second intermediate vulcanization device 40, and the final vulcanization device 20 are connected in series in sequence. The first intermediate vulcanization device 30 includes a first pulping tank 31. The feeding end of the first pulping tank 31 is respectively communicated with the output end of the sulfide precipitate of the first intermediate vulcanization device 30 and the output end of the original solution of the industrial waste liquid, and the output end of the first pulping tank 31 is communicated with the primary vulcanization device 10. Moreover, the second intermediate vulcanization device 40 includes a second pulping tank 43. The feeding end of the second pulping tank 43 is respectively communicated with the output end of the sulfide precipitate of the second intermediate vulcanization device 40 and the output end of the original solution of the industrial waste liquid, and the output end of the second pulping tank 43 is communicated with the primary vulcanization device 10. Specifically, the primary vulcanization device 10, the first intermediate vulcanization device 30, the second intermediate vulcanization device 40 and the final vulcanization device 20 all include a vulcanization reactor and a liquid-solid separation device arranged in sequence along the flowing direction of the industrial waste liquid. The feeding end of the first pulping tank 31 is communicated with the output end of the sulfide precipitate of the first intermediate liquid-solid separation device 32 of the first intermediate vulcanization device 30, and the feeding end of the second pulping tank 43 is communicated with the output end of the sulfide precipitate of the second intermediate liquid-solid separation device 42 of the second intermediate vulcanization device 40. Among them, a feeding port for adding a vulcanizing agent is opened at the feeding end of the vulcanization reactor.

[0050] In specific practice, first, a large amount of waste acid is produced by the copper smelting flue gas acid-making purification device to form the original solution of industrial waste acid (containing valuable metal Cu ions and harmful element As ions). The original solution of the industrial waste liquid is pumped to the primary vulcanization reactor 11 of the primary vulcanization device 10 through a pipeline. At the same time, the vulcanizing agent is added through the feeding port of the primary vulcanization reactor 11 to carry out a vulcanization reaction with the original solution. The treated liquid after the vulcanization reaction is pumped to the primary liquid-solid separation device 12 of the primary vulcanization device 10 for solid-liquid separation treatment. The separated primary sulfide precipitate is recovered or sold as a product, while the primary clear liquid is pumped to the first intermediate vulcanization reactor 31 of the first intermediate vulcanization device 30;

[0051] Secondly, the primary supernatant reacts with the sulfiding agent added through the feed inlet of the first intermediate-stage sulfiding reactor 31. The treated liquid after the sulfiding reaction is pumped to the first-stage liquid-solid separation equipment 32 of the first intermediate-stage sulfiding device 30 for solid-liquid separation treatment. The separated first intermediate-stage sulfide precipitate is pumped to the first slurry tank 33, and is mixed and stirred evenly with the original solution of the industrial waste liquid pumped to the first slurry tank 33 through the first stirrer 331, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS, and then are pumped to the primary sulfiding reactor 11 for sulfiding reaction, so that the primary sulfide precipitate inhibits the production of As2S3 in the sulfiding reaction of the primary sulfiding reactor 11, and realizes that the primary sulfide precipitate produced in the sulfiding reaction of the primary sulfiding reactor 11 is mainly CuS precipitate (only containing a small amount of As2S3); while the separated first intermediate-stage supernatant is pumped to the second intermediate-stage sulfiding reactor 41 of the second intermediate-stage sulfiding device 40;

[0052] Thirdly, the first intermediate-stage supernatant reacts with the sulfiding agent added through the feed inlet of the second intermediate-stage sulfiding reactor 41. The treated liquid after the sulfiding reaction is pumped to the second intermediate-stage solid-liquid separation equipment 42 of the second intermediate-stage sulfiding device 40 for solid-liquid treatment. The separated second intermediate-stage sulfide precipitate is pumped to the second slurry tank 43, and is mixed and stirred evenly with the original solution of the industrial waste liquid pumped to the second slurry tank 43 through the second stirrer 431, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS, and then are pumped to the primary sulfiding reactor 11 for sulfiding reaction, so that the primary sulfide precipitate inhibits the production of As2S3 in the sulfiding reaction of the primary sulfiding reactor 11, and realizes that the primary sulfide precipitate produced in the sulfiding reaction of the primary sulfiding reactor 11 is mainly CuS precipitate (only containing a small amount of As2S3); while the separated second intermediate-stage supernatant is pumped to the final-stage sulfiding reactor 21 of the final-stage sulfiding device 20;

[0053] Finally, the second intermediate-stage supernatant reacts with the sulfiding agent added through the feed inlet of the final-stage sulfiding reactor 21. The treated liquid after the sulfiding reaction is pumped to the final-stage solid-liquid separation equipment 22 of the final-stage sulfiding device 20 for solid-liquid separation treatment. The separated final-stage sulfide precipitate, which is mainly As2S3 precipitate (only containing a small amount of CuS), is collected for centralized pollutant treatment; while the separated final-stage supernatant can be transported to the next process for utilization.

[0054] It should be noted that in the above specific practice, the addition amount of the sulfiding agent is adjusted by the redox potential value in the liquid after the sulfiding reaction in the sulfiding reactors at each stage.

[0055] Such as Figure 4As shown in the figure, a method for separating Cu and As from industrial waste liquid provided in this embodiment is applied to a system for separating Cu and As from industrial waste liquid. The system includes a primary sulfidation device, a final sulfidation device, a first intermediate sulfidation device and a second intermediate sulfidation device arranged between the primary sulfidation device and the final sulfidation device. The primary sulfidation device, the first intermediate sulfidation device, the second intermediate sulfidation device and the final sulfidation device are connected in series in sequence; the first intermediate sulfidation device includes a first pulping tank. The feeding end of the first pulping tank is respectively communicated with the output end of the first intermediate sulfide precipitate of the first intermediate sulfidation device and the output end of the original solution of the industrial waste liquid, and the output end of the first pulping tank is communicated with the primary sulfidation device; moreover, the second intermediate sulfidation device includes a second pulping tank. The feeding end of the second pulping tank is respectively communicated with the output end of the sulfide precipitate of the second intermediate sulfidation device and the output end of the original solution of the industrial waste liquid, and the output end of the second pulping tank is communicated with the primary sulfidation device. The method includes the following steps S201 to S204:

[0056] S201: The original solution of the industrial waste liquid is sent into the primary sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, primary sulfide precipitate and primary clear liquid are produced through liquid-solid separation treatment;

[0057] S202: The primary clear liquid is sent into the first of the first intermediate sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, first intermediate sulfide precipitate and first intermediate clear liquid are produced through liquid-solid separation treatment. The first intermediate sulfide precipitate is sent to the first pulping tank through a pipeline segment. At the same time, the first pulping tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the primary sulfidation device through a pipeline, so that the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate;

[0058] S203: The first intermediate clear liquid is sent into the second of the second intermediate sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, second intermediate sulfide precipitate and second intermediate clear liquid are produced through liquid-solid separation treatment. The second intermediate sulfide precipitate is sent to the second pulping tank through a pipeline segment. At the same time, the second pulping tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the primary sulfidation device through a pipeline, so that the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate;

[0059] S204: The second intermediate clear liquid is sent into the final sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, final sulfide precipitate and final clear liquid are produced through liquid-solid separation treatment, so that the final sulfidation device produces the final sulfide precipitate mainly composed of As2S3.

[0060] Example 3

[0061] An embodiment of the present invention provides a method for separating Cu and As in industrial waste liquid, which is applied to a system for separating Cu and As in industrial waste liquid. As Figure 5 shown, the system includes a primary sulfidation device 10, a final sulfidation device 20, a first intermediate sulfidation device 30 and a second intermediate sulfidation device 40 arranged between the primary sulfidation device 10 and the final sulfidation device 20. The primary sulfidation device 10, the first intermediate sulfidation device 30, the second intermediate sulfidation device 40, and the final sulfidation device 20 are connected in series in sequence. The first intermediate sulfidation device 30 includes a first slurry tank 33. The feeding end of the first slurry tank 33 is respectively communicated with the output end of the sulfide precipitate of the first intermediate sulfidation device 30 and the output end of the original solution of the industrial waste liquid, and the output end of the first slurry tank 33 is communicated with the primary sulfidation device 10; moreover, the second intermediate sulfidation device 40 includes a second slurry tank 43. The feeding end of the second slurry tank 43 is respectively communicated with the output end of the sulfide precipitate of the second intermediate sulfidation device 40 and the output end of the original solution of the industrial waste liquid, and the output end of the second slurry tank 43 is communicated with the first intermediate sulfidation device 30. Specifically, the primary sulfidation device 10, the first intermediate sulfidation device 30, the second intermediate sulfidation device 40, and the final sulfidation device 20 all include a sulfidation reactor and a liquid-solid separation device arranged in sequence along the flow direction of the industrial waste liquid. The feeding end of the first slurry tank 33 is communicated with the output end of the sulfide precipitate of the liquid-solid separation device of the first intermediate sulfidation device 30, and the feeding end of the second slurry tank 43 is communicated with the output end of the sulfide precipitate of the liquid-solid separation device of the second intermediate sulfidation device 40; wherein, a feeding port for adding a sulfiding agent is opened at the feeding end of the sulfidation reactor.

[0062] In specific practice, first, a large amount of waste acid is produced by the acid purification device for copper smelting flue gas to form the original solution of industrial waste acid (containing valuable metal Cu ions and harmful element As ions). The original solution of the industrial waste liquid is pumped to the primary sulfidation reactor 11 of the primary sulfidation device 10 through a pipeline. At the same time, the sulfiding agent is added through the feeding port of the primary sulfidation reactor 11 to carry out a sulfidation reaction with the original solution. The treated liquid after the sulfidation reaction is pumped to the primary liquid-solid separation device 12 of the primary sulfidation device 10 for solid-liquid separation treatment. The separated primary sulfide precipitate is recovered or sold as a product, and the primary clear liquid is pumped to the first intermediate sulfidation reactor 31 of the first intermediate sulfidation device 30;

[0063] Secondly, the primary clear liquid undergoes a sulfidation reaction with the sulfiding agent added through the feed inlet of the first intermediate-stage sulfidation reactor 31. The treated liquid after the sulfidation reaction is pumped to the first-stage liquid-solid separation equipment 32 of the first intermediate-stage sulfidation device 30 for solid-liquid separation treatment. The separated first intermediate-stage sulfide precipitate is pumped to the first pulping tank 33, where it is mixed and stirred evenly with the original solution of the industrial waste liquid pumped to the first pulping tank 33 through the first stirrer 331. After the Cu ions and As2S3 in the original solution react to displace As ions and CuS, it is pumped to the primary sulfidation reactor 11 for sulfidation reaction, so that the primary sulfide precipitate in the sulfidation reaction of the primary sulfidation reactor 11 inhibits the production of As2S3, and the primary sulfide precipitate produced in the sulfidation reaction of the primary sulfidation reactor 11 is mainly CuS precipitate (only containing a small amount of As2S3). The separated first intermediate-stage clear liquid is pumped to the second intermediate-stage sulfidation reactor 41 of the second intermediate-stage sulfidation device 40;

[0064] Thirdly, the first intermediate-stage clear liquid undergoes a sulfidation reaction with the sulfiding agent added through the feed inlet of the second intermediate-stage sulfidation reactor 41. The treated liquid after the sulfidation reaction is pumped to the second intermediate-stage solid-liquid separation equipment 42 of the second intermediate-stage sulfidation device 40 for solid-liquid treatment. The separated second intermediate-stage sulfide precipitate is pumped to the second pulping tank 43, where it is mixed and stirred evenly with the original solution of the industrial waste liquid pumped to the second pulping tank 43 through the second stirrer 431. After the Cu ions and As2S3 in the original solution react to displace As ions and CuS, it is pumped to the first intermediate-stage sulfidation reactor 31 for sulfidation reaction, so that the first intermediate-stage sulfide precipitate in the sulfidation reaction of the first intermediate-stage sulfidation reactor 31 inhibits the production of As2S3, and the first intermediate-stage sulfide precipitate produced in the sulfidation reaction of the first intermediate-stage sulfidation reactor 31 is mainly CuS precipitate (only containing a small amount of As2S3). The separated second intermediate-stage clear liquid is pumped to the final-stage sulfidation reactor 21 of the final-stage sulfidation device 20;

[0065] Finally, the second intermediate-stage clear liquid undergoes a sulfidation reaction with the sulfiding agent added through the feed inlet of the final-stage sulfidation reactor 21. The treated liquid after the sulfidation reaction is pumped to the final-stage solid-liquid separation equipment 22 of the final-stage sulfidation device 20 for solid-liquid separation treatment. The separated final-stage sulfide precipitate, which is mainly As2S3 precipitate (only containing a small amount of CuS), is collected for centralized pollutant treatment; the separated final-stage clear liquid can be transported to the next process for utilization.

[0066] It should be noted that in the above specific practice, the addition amount of the sulfiding agent is adjusted according to the redox potential value in the liquid after the sulfidation reaction in each stage of the sulfidation reactor.

[0067] Such asFigure 6 As shown in the figure, a method for separating Cu and As in industrial waste liquid provided in this embodiment is applied to a system for separating Cu and As in industrial waste liquid. The system includes a primary sulfidation device, a final sulfidation device, a first intermediate sulfidation device, and a second intermediate sulfidation device disposed between the primary sulfidation device and the final sulfidation device. The primary sulfidation device, the first intermediate sulfidation device, the second intermediate sulfidation device, and the final sulfidation device are connected in series in sequence. The first intermediate sulfidation device includes a first slurry tank. The feeding end of the first slurry tank is respectively communicated with the output end of the first intermediate sulfide precipitate of the first intermediate sulfidation device and the output end of the original solution of the industrial waste liquid, and the output end of the first slurry tank is communicated with the primary sulfidation device. Moreover, the second intermediate sulfidation device includes a second slurry tank. The feeding end of the second slurry tank is respectively communicated with the output end of the sulfide precipitate of the second intermediate sulfidation device and the output end of the original solution of the industrial waste liquid, and the output end of the second slurry tank is communicated with the primary sulfidation device. The method includes the following steps S301 to S304:

[0068] S301: The original solution of the industrial waste liquid is sent into the primary sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, primary sulfide precipitate and primary clear liquid are produced through liquid-solid separation treatment;

[0069] S302: The primary clear liquid is sent into the first of the first intermediate sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, first intermediate sulfide precipitate and first intermediate clear liquid are produced through liquid-solid separation treatment. The first intermediate sulfide precipitate is sent to the first slurry tank through a pipeline segment. At the same time, the first slurry tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the primary sulfidation device through a pipeline, so that the primary sulfidation device produces the primary sulfide precipitate mainly composed of CuS precipitate;

[0070] S303: The first intermediate clear liquid is sent into the second of the second intermediate sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, second intermediate sulfide precipitate and second intermediate clear liquid are produced through liquid-solid separation treatment. The second intermediate sulfide precipitate is sent to the second slurry tank through a pipeline segment. At the same time, the second slurry tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the first intermediate sulfidation device through a pipeline, so that the first intermediate sulfidation device produces the first intermediate sulfide precipitate mainly composed of CuS precipitate;

[0071] S204: Feed the second intermediate-stage supernatant into the final-stage sulfidation device through a pipeline for sulfidation reaction. After the sulfidation reaction is completed, carry out liquid-solid separation treatment to produce final-stage sulfide precipitate and final-stage supernatant, so that the final-stage sulfide precipitate mainly composed of As2S3 is produced by the final-stage sulfidation device.

[0072] The foregoing are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A system for separating Cu and As from industrial waste liquid, characterized in that, The system includes a primary vulcanization device, a final vulcanization device, and an intermediate vulcanization device disposed between the primary vulcanization device and the final vulcanization device. The primary vulcanization device, the intermediate vulcanization device, and the final vulcanization device are connected in series in sequence. The intermediate vulcanization device includes a pulping tank. The feeding end of the pulping tank is respectively communicated with the output end of the sulfide precipitate of the intermediate vulcanization device and the output end of the original solution of the industrial waste liquid. And the output end of the pulping tank is communicated with the primary vulcanization device. A stirrer for stirring the sulfide precipitate of the intermediate vulcanization device and the original solution of the industrial waste liquid is provided in the pulping tank, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS. The primary vulcanization device, the intermediate vulcanization device, and the final vulcanization device all include a vulcanization reactor and a liquid-solid separation device arranged in sequence along the flowing direction of the industrial waste liquid. The feeding end of the pulping tank is communicated with the output end of the sulfide precipitate of the liquid-solid separation device of the intermediate vulcanization device. The feeding end of the vulcanization reactor is provided with a feeding port for adding a vulcanizing agent, and the addition amount of the vulcanizing agent is adjusted by the redox potential value of the waste liquid after the vulcanization reaction in the vulcanization reactor.

2. A method for separating Cu and As from industrial waste liquid, which is applied to the system for separating Cu and As from industrial waste liquid as described in claim 1, characterized in that, The method includes: The original solution of the industrial waste liquid is sent into the primary vulcanization device through a pipeline for vulcanization reaction. After the vulcanization reaction is completed, a primary sulfide precipitate and primary clear liquid are produced through liquid-solid separation treatment. The primary clear liquid is sent into the intermediate vulcanization device through a pipeline for vulcanization reaction. After the vulcanization reaction is completed, an intermediate sulfide precipitate and intermediate clear liquid are produced through liquid-solid separation treatment. The intermediate sulfide precipitate is sent to the pulping tank through a pipeline segment. At the same time, the pulping tank adds the original solution of the industrial waste liquid through a pipeline for stirring. After being stirred evenly, it is sent to the primary vulcanization device through a pipeline, so that the primary vulcanization device produces the primary sulfide precipitate mainly composed of CuS precipitate. The intermediate clear liquid is sent into the final vulcanization device through a pipeline for vulcanization reaction. After the vulcanization reaction is completed, a final sulfide precipitate and final clear liquid are produced through liquid-solid separation treatment, so that the final vulcanization device produces the final sulfide precipitate mainly composed of As2S3.

3. The method for separating Cu and As in industrial waste liquid according to claim 2, characterized in that, The sulfide precipitate of the intermediate vulcanization device and the original solution of the industrial waste liquid are mixed and stirred in the pulping tank, so that Cu ions and As2S3 in the original solution react to displace As ions and CuS.

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