Device for extracting nickel from nickel-containing wastewater through advection electrolysis

Abstract

The utility model discloses a device for extracting nickel from nickel-containing wastewater through advection electrolysis. The device comprises a precipitation system (1), solid-liquid separation equipment (2), a pretreatment system (3), an electrolysis system (4) and a dosing system (5), the nickel-containing wastewater is precipitated in the precipitation system (1) and then subjected to solid-liquid separation treatment through the solid-liquid separation equipment (2), the nickel-containing precipitate obtained after solid-liquid separation is subjected to chemical adding and dissolving through the chemical adding system (5) in the pretreatment system (3) to form a stable electrolyte, and then electrolysis is conducted in the electrolysis system (4) so that nickel simple substances can be separated out on a negative plate. Aiming at the existing electroplating nickel-containing wastewater, the nickel extraction technology in the nickel-containing wastewater is improved, so that the nickel in the nickel-containing wastewater can be separated out and collected on the final electrolytic cathode under the advection electrolysis condition.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrolysis, and in particular relates to a device for extracting nickel from nickel-containing wastewater through advection electrolysis. Background Art

[0002] Nickel-containing wastewater is a common wastewater in the electroplating industry. The nickel ion concentration in electroplating nickel wastewater is usually high. Directly treating electroplating wastewater as sewage will not only waste a large amount of nickel ions, but also increase the cost of process treatment.

[0003] At present, the technical methods used in China to treat nickel-plating wastewater include chemical method, membrane method, ion exchange method and other methods. For the chemical method, sodium hydroxide or calcium hydroxide is added to the nickel-containing wastewater, and then a flocculant is added to make the nickel in the nickel-containing wastewater settle from the wastewater in the form of sludge. For the membrane method, a reverse osmosis membrane is used to recover the heavy metals in it, but it is difficult to remove impurities in the wastewater using the membrane method. For the ion exchange method, ion exchange resin is used to absorb nickel ions in the wastewater, and then chemical agents are used to elute the nickel ions adsorbed in the resin.

[0004] For example, the prior art "Resource recovery process for pure water and pure nickel from electroplating nickel rinsing wastewater" (publication number CN 105858987 A) introduces a method of using cationic resin to adsorb nickel ions and then eluting and regenerating with sulfuric acid solution to obtain a nickel sulfate solution. As mentioned above, this method has shortcomings in some scenarios. Utility Model Content

[0005] In view of the problems existing in the prior art, an improved chemical method is used in the present device. By adding only sodium hydroxide, a relatively pure nickel hydroxide precipitate can be obtained, and then nickel hydroxide is obtained by solid-liquid separation equipment, and then a nickel sulfate electrolyte is obtained by adding drugs. Then, nickel element can be obtained by subsequent electrolysis, which has economic value and can reduce the nickel ion concentration in the wastewater and reduce the subsequent treatment cost.

[0006] In order to achieve the above purpose, the utility model provides a device for extracting nickel from nickel-containing wastewater by advection electrolysis, which solves the problem of nickel extraction efficiency in nickel-containing wastewater.

[0007] The technical solution adopted by the utility model is:

[0008] A device for extracting nickel from nickel-containing wastewater by advection electrolysis comprises a precipitation system 1, a solid-liquid separation device 2, a pretreatment system 3, an electrolysis system 4, and a dosing system 5.

[0009] The nickel-containing wastewater is precipitated in a sedimentation system 1 and then subjected to solid-liquid separation treatment by a solid-liquid separation device 2. The nickel-containing precipitate after solid-liquid separation is dissolved in a pretreatment system 3 by a dosing system 5 to form a stable electrolyte, and then electrolyzed in an electrolysis system 4 to precipitate nickel on the cathode plate.

[0010] The innovative features of this utility model:

[0011] A device for extracting nickel from nickel-containing wastewater by advection electrolysis combines different processes and uses advection electrolysis to electrolytically extract nickel.

[0012] Beneficial effects of the utility model:

[0013] 1. By using the advection electrolysis technology, metallic nickel can be obtained at the cathode.

[0014] 2. Stable electrolyte can be obtained through different dosing systems.

[0015] 3. By combining different processes, the occurrence of side reactions during the electrolysis process can be reduced.

[0016] 4. The process equipment can be automated and run continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the device for extracting nickel from nickel-containing wastewater by horizontal electrolysis in Example 1.

[0018] Figure 2 This is a schematic diagram of the device for extracting nickel from nickel-containing wastewater by horizontal electrolysis in Example 2. DETAILED DESCRIPTION

[0019] The utility model is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The utility model aims at improving the nickel extraction technology of the existing electroplating nickel-containing wastewater, so that the nickel in the nickel-containing wastewater can be precipitated and collected on the final electrolytic cathode under the condition of advection electrolysis.

[0021] The device for extracting nickel from nickel-containing wastewater by advection electrolysis in the embodiment comprises: a precipitation system 1, a solid-liquid separation device 2, a pretreatment system 3, an electrolysis system 4, a dosing system 5, and pumps 6-9.

[0022] The sedimentation system 1 includes a sedimentation tank 10 and a sedimentation mixer 11 .

[0023] The pre-treatment system 3 includes a pre-treatment tank 12 and a pre-treatment mixer 13 .

[0024] The electrolysis system 4 includes a rectifier 14 , an electrode sheet 15 , and an electrolytic cell 16 .

[0025] The dosing system 5 includes a sulfuric acid dosing device 17 , a sodium chloride dosing device 18 , a boric acid dosing device 19 , and a sodium hydroxide dosing device 20 .

[0026] In the device for extracting nickel from nickel-containing wastewater by horizontal electrolysis in Example 1, the electroplating nickel-containing wastewater enters the sedimentation barrel 10 through the raw water pump 6, the sodium hydroxide agent is added to the sedimentation barrel 10 through the sodium hydroxide dosing equipment 20, the sedimentation barrel 10 is stirred by the sedimentation stirrer 11, the reaction is carried out in the sedimentation barrel 10 to produce nickel hydroxide precipitate, and the liquid in the sedimentation barrel 10 is pumped to the solid-liquid separation equipment 2 for solid-liquid separation by the separation equipment water supply pump 7.

[0027] After solid-liquid separation by the solid-liquid separation device 2, nickel hydroxide precipitate and clear liquid are obtained. The clear liquid is collected for subsequent treatment and meets the discharge standards. The nickel hydroxide precipitate is collected and enters the pretreatment tank 12. Sulfuric acid, boric acid and sodium chloride are added to the pretreatment tank respectively through the sulfuric acid dosing device 17, the sodium chloride dosing device 18 and the boric acid dosing device 19. The pretreatment mixer 13 is turned on to completely dissolve the nickel mud to obtain a solution with a pH of 3-5. A suitable and stable electrolyte is prepared by controlling the dosage of different drugs, and the electrolyte is pumped to the electrolytic cell 16 by the liquid inlet pump 8 for electrolysis.

[0028] When the electrolyte is pumped into the electrolytic cell 16 through the liquid inlet pump 8, a constant electrolysis current is provided to the electrode sheet 15 through the rectifier 14, and the electrolyte is circulated between the electrolytic cell and the pretreatment cell through the circulation pump 9, nickel element can be obtained on the cathode through electrolysis.

[0029] When the impurity content of some electroplating wastewater is high, the utility model patent operates through the second implementation mode, which is as follows:

[0030] In the device for extracting nickel from nickel-containing wastewater by horizontal electrolysis of this embodiment 2, the electroplating nickel-containing wastewater enters the sedimentation barrel 10 through the raw water pump 6, the sodium hydroxide agent is added to the sedimentation barrel 10 through the sodium hydroxide dosing equipment 20, the sedimentation barrel 10 is stirred by the sedimentation stirrer 11, the reaction is carried out in the sedimentation barrel 10 to produce nickel hydroxide precipitate, and the liquid in the sedimentation barrel 10 is pumped to the solid-liquid separation equipment 2 for solid-liquid separation by the separation equipment water supply pump 7.

[0031] After solid-liquid separation by the solid-liquid separation equipment 2, nickel hydroxide precipitate and clear liquid are obtained. The clear liquid is collected for subsequent treatment and discharged in compliance with the standards. The nickel hydroxide precipitate is collected and enters the pretreatment tank 12. Since the raw water contains a large amount of impurities, after the nickel hydroxide precipitate enters the pretreatment tank, clean water is added and stirred by the pretreatment stirrer 13. The liquid is then pumped to the solid-liquid separation equipment 2 for solid-liquid separation by the separation equipment water supply pump 7. The number of cleaning times can be adjusted according to the impurity content in the raw water. The nickel hydroxide precipitate obtained after washing is collected and enters the pretreatment tank 12, and sulfuric acid, boric acid and sodium chloride are added to the pretreatment tank respectively through the sulfuric acid dosing device 17, the sodium chloride dosing device 18 and the boric acid dosing device 19, and the pretreatment mixer 13 is turned on to completely dissolve the nickel mud. When the nickel mud is completely dissolved, if the pH is greater than 5, sulfuric acid is added through the sulfuric acid dosing device 17 to adjust the pH to 3-5; if the pH is less than 3, sodium hydroxide is added through the sodium hydroxide dosing device 20 to adjust the pH to 3-5; the configured electrolyte is pumped to the electrolytic tank 16 by the liquid inlet pump 8 for electrolysis.

[0032] When the electrolyte is transported to the electrolytic cell 16 through the liquid inlet pump 8, a constant electrolysis current is provided to the electrode sheet 15 through the rectifier 14, and the electrolyte is circulated between the electrolytic cell and the pretreatment cell through the circulation pump 9, nickel element can be obtained on the cathode through electrolysis.

[0033] This device can reduce the nickel ion content in electroplating wastewater, which not only reduces the cost of subsequent treatment, but also the obtained nickel element has a higher economic value.

[0034] The above are embodiments of the present invention, but the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention. Any omissions, modifications, equivalent substitutions, etc. made according to the scope of the patent application of the present invention without departing from the principle and spirit of the present invention shall be included in the protection scope of the claims of this patent.

Claims

1. A device for extracting nickel from nickel-containing wastewater by advection electrolysis, characterized in that: It includes a precipitation system (1), a solid-liquid separation device (2), a pretreatment system (3), an electrolysis system (4), and a dosing system (5); The precipitation system (1) is connected to the solid-liquid separation device (2), the dosing system (5) is connected to the pretreatment system (3), and the pretreatment system (3) is connected to the electrolysis system (4); The sedimentation system (1) comprises a sedimentation barrel (10) and a sedimentation stirrer (11); the dosing system (5) is connected to the sedimentation barrel (10); the sedimentation barrel (10) uses the sedimentation stirrer (11) to stir and react; the liquid in the sedimentation barrel (10) is pumped to the solid-liquid separation device (2) for solid-liquid separation via a separation device water supply pump; The pretreatment system (3) comprises a pretreatment tank (12) and a pretreatment stirrer (13); the pretreatment tank (12) is connected to the dosing system (5); the pretreatment tank (12) completely dissolves the nickel sludge by turning on the pretreatment stirrer (13), and pumps the nickel sludge into the electrolytic tank of the electrolysis system (4) through a liquid inlet pump for electrolysis; The electrolysis system (4) comprises a rectifier (14), an electrode sheet (15), and an electrolytic cell (16); in the electrolytic cell (16), a constant electrolysis current is provided to the electrode sheet (15) via the rectifier (14), and an electrolyte is circulated between the electrolytic cell (16) and a pretreatment cell of the pretreatment system (3) via a circulation pump.

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