Equipment and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry

Abstract

The present invention discloses an apparatus and method for the cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, comprising a pretreatment filter mechanism, a chromium recovery unit and a nickel recovery unit which are sequentially connected and arranged; the pretreatment filter mechanism comprises a vertically extending filter mechanism flow pipe, a plurality of filter housing support rings are fixed in the filter mechanism flow pipe, a filter fixed cone shell with a downward opening is fixed on the filter housing support ring; a plurality of filter leak holes are provided on the side wall of the filter fixed cone shell; the chromium recovery unit comprises a chromium reduction reaction mechanism and a chromium precipitation reaction mechanism; the nickel recovery unit comprises a vertically extending nickel recovery flow pipe, a nickel elution flow pipe coaxially extending therewith is fixed in the nickel recovery flow pipe; the present invention has a high separation capacity, can accurately separate chromium ions and nickel ions from the mixed waste liquid, ensure that the recovered chromium and nickel have high purity, and fully separate the chromium ions and nickel ions from other impurity ions through corresponding ion exchange resins to avoid mutual interference.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy metal recovery, in particular to a device and method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry. Background Art

[0002] Chromium-nickel mixed waste liquid in the electroplating industry is a waste liquid containing two heavy metal ions, chromium and nickel, generated during the electroplating process. Electroplating is a process that uses the principle of electrolysis to plate a metal film on the surface of metal or other materials. In the chromium and nickel plating processes, a large amount of electroplating solution containing chromium salts and nickel salts is used. After the electroplating solution has been used for a period of time, due to the consumption of the electroplating solution components and the mixing of impurities, the performance of the electroplating solution decreases and it can no longer meet the electroplating requirements. It will be discarded and form chromium-nickel mixed waste liquid;

[0003] Both chromium and nickel are heavy metals. Discharge of untreated chromium-nickel wastewater can cause serious pollution to soil, water, and the atmosphere. Heavy metal ions accumulate in soil and water, and once they enter the food chain, they can harm ecosystems and human health.

[0004] The existing chromium-nickel mixed waste liquid recovery equipment still has shortcomings in process convenience and recovery efficiency, and needs further improvement and optimization. Summary of the Invention

[0005] The purpose of the present invention is to provide an apparatus and method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, which can effectively separate the chromium and nickel in the chromium-nickel mixed waste liquid and recover them separately.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A device and method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, comprising a pretreatment filtration mechanism, a chromium recovery unit, and a nickel recovery unit which are sequentially connected;

[0008] The chromium recovery unit includes a chromium reduction reaction mechanism and a chromium precipitation reaction mechanism;

[0009] The chromium reduction reaction mechanism includes a chromium reduction reaction flow pipe, a side wall of which is provided with a plurality of dosing pipe receiving holes extending radially therethrough, a reducing agent dosing pipe being slidably connected to the dosing pipe receiving holes, and a plurality of dosing nozzles for the reducing agent dosing pipe being fixed on the outside thereof and in communication therewith;

[0010] A dosing tube drive housing is fixed on the outside of the chromium reduction reaction circulation pipe, and a dosing tube drive telescopic rod for driving the reducing agent dosing tube to move is arranged inside the dosing tube drive housing;

[0011] The output end of the chromium reduction reaction flow pipe is connected to a chromium reduction reaction static tank;

[0012] The chromium precipitation reaction mechanism includes a chromium precipitation holding tank, in which a plurality of chromium precipitation reaction flow slots are fixed;

[0013] The input end of the chromium precipitation reaction flow tank is fixed with a precipitation reaction input pipe connected thereto, the other end of the precipitation reaction input pipe is connected to the chromium reduction reaction static tank, and the output end of the chromium precipitation reaction flow tank is fixed with a chromium precipitation reaction output pipe and a chromium precipitation recovery pipe connected thereto;

[0014] A precipitation agent delivery pipe is fixed in the input end of the chromium precipitation reaction flow tank, and a plurality of precipitation agent nozzles are provided on the lower side of the precipitation agent delivery pipe;

[0015] The nickel recovery unit includes a vertically extending nickel recovery circulation pipe, in which a coaxially extending nickel elution circulation pipe is fixed;

[0016] A nickel recovery channel is formed between the inner wall of the nickel recovery circulation tube and the outer wall of the nickel elution circulation tube;

[0017] A cylindrical ion exchange resin is fixed on the outer wall of the nickel elution flow tube;

[0018] A nickel recovery input pipe connected to the interior of the nickel recovery circulation pipe is fixed at the lower end thereof, and a nickel recovery output pipe connected to the interior thereof is fixed at the top of the nickel recovery circulation pipe;

[0019] The nickel recovery input pipe is connected to the chromium precipitation reaction output pipe;

[0020] A nickel elution input pipe connected to the interior of the nickel elution circulation pipe is fixed on the top of the nickel elution circulation pipe.

[0021] Preferably, the pre-treatment filter mechanism comprises a filter mechanism flow pipe extending vertically, a plurality of filter housing support rings are fixed in the filter mechanism flow pipe, and a filter fixing cone with an opening facing downward is fixed on the filter housing support ring;

[0022] There are multiple filter holes on the side wall of the filter fixed cone shell;

[0023] A filter input pipe connected to the interior is fixed to the top of the filter mechanism flow pipe, and a filter output pipe connected to the interior is fixed to the bottom of the filter mechanism flow pipe;

[0024] The filter output pipe is connected to the regulating tank, and the input end of the chromium reduction reaction flow pipe is connected to the regulating tank;

[0025] A filter residue collection tank is formed between the upper side of the filter shell support ring and the outer side wall of the lower end of the filter fixed cone shell. A plurality of filter residue discharge pipes connected to the filter residue collection tank are fixed on the outside of the filter mechanism flow pipe, and a filter residue discharge control valve is provided on the filter residue discharge pipe.

[0026] Description: The conical structure of the filter fixed cone shell allows the intercepted particle residue to be automatically distributed and accumulated on the outer ring at the bottom of the cone structure, avoiding clogging of the filter fixed cone shell and allowing the filter device to always maintain good filtering performance.

[0027] Preferably, a filter hole adjustment mechanism is provided on the inner side of the filter fixed cone shell, and the filter hole adjustment mechanism comprises a filter hole adjustment cone shell rotatably connected to the inner side of the filter fixed cone shell;

[0028] There are multiple filter hole adjustment holes on the side wall of the filter hole adjustment cone shell, and the filter hole adjustment holes are connected to each filter hole in a one-to-one correspondence;

[0029] A rotating support ring coaxially arranged with the filter mechanism flow tube is fixed on the top of the filter fixed cone shell, and a rotating support cylinder with an upward opening is fixed on the top of the filter hole adjustment cone shell. The rotating support cylinder is rotatably connected to the outside of the rotating support ring.

[0030] Description: The pre-treatment filtration mechanism adopts a stepped filter hole arrangement to separate the particle residues in the chromium-nickel mixed waste liquid in batches according to the particle size.

[0031] Preferably, a wake drive mechanism is provided in the chromium reduction reaction flow pipe, the wake drive mechanism comprising a wake drive tube shell coaxially fixed in the chromium reduction reaction flow pipe, a wake drive shaft is rotatably connected to the backwater end of the wake drive tube shell, and a plurality of wake drive blades are fixed to the wake drive shaft;

[0032] A wake drive motor for driving the wake drive shaft to rotate is fixed in the wake drive tube housing;

[0033] The wake driving tube shell is fixedly connected to the inner side wall of the chromium reduction reaction flow tube through a plurality of radial guide plates.

[0034] Description: The tail flow driving mechanism is used to drive the chromium-nickel mixed waste liquid to generate swirl during the circulation process, which is beneficial to the full mixing of the chromium-nickel mixed waste liquid and the chromium reducing agent.

[0035] Preferably, a precipitation partitioning barrier mechanism is provided at the bottom of the chromium precipitation reaction flow channel, wherein the bottom of the chromium precipitation reaction flow channel has a plurality of vertically penetrating barrier plate sliding grooves, and the precipitation partitioning barrier mechanism includes partitioning barrier plates slidably connected in the barrier plate sliding grooves;

[0036] A barrier plate drive housing is fixed at the bottom of the chromium precipitation reaction flow channel at the barrier plate sliding groove. A barrier plate drive fixed cylinder with an upward opening is fixed in the barrier plate drive housing. A barrier plate drive sliding cylinder with a downward opening is slidably connected in the barrier plate drive fixed cylinder. The outer end of the barrier plate drive sliding cylinder is fixedly connected to the lower end of the partition barrier plate.

[0037] A blocking plate driving telescopic rod for driving the blocking plate driving sliding cylinder to move up and down is arranged in the blocking plate driving fixed cylinder.

[0038] Description: The chromium hydroxide precipitate is intercepted by a precipitation partition barrier mechanism. In the initial state, the top of the partition barrier plate is flush with the bottom of the chromium precipitation reaction flow channel. When the chromium hydroxide precipitate needs to be intercepted, the partition barrier plate is blocked in the chromium precipitation reaction flow channel. The chromium hydroxide precipitate accumulates at the bottom of the chromium precipitation reaction flow channel under the action of its own weight and is blocked and intercepted by the partition barrier plate.

[0039] Preferably, a precipitation and flushing mechanism is provided on the top of the chromium precipitation reaction circulation tank, and the precipitation and flushing mechanism includes a precipitation and flushing support slide rail fixed on the top of the chromium precipitation reaction circulation tank, and a precipitation and flushing support slider is slidably connected to the precipitation and flushing support slide rail, and a flushing support plate is fixed on the precipitation and flushing support slider, and multiple precipitation and flushing conveying pipes are fixed on the lower side of the flushing support plate, and the lower side of the precipitation and flushing conveying pipe has multiple precipitation and flushing nozzles connected to the interior thereof.

[0040] Description: Clean water is introduced into each precipitation flushing conveying pipe, and the clean water is sprayed out from each precipitation flushing nozzle to flush the chromium hydroxide precipitate accumulated in the chromium precipitation reaction flow groove, and the precipitation flushing support slider can be driven by the servo motor to reciprocate along the precipitation flushing support slide rail to fully flush the chromium hydroxide precipitate in the chromium precipitation reaction flow groove. The precipitation recovery control valve is opened, and the chromium hydroxide precipitate is discharged from the chromium precipitation recovery pipe under the flushing and carrying of clean water, thereby realizing the recovery of the chromium hydroxide precipitate.

[0041] Preferably, a wave flow control mechanism is provided at the bottom of the chromium precipitation reaction flow channel, wherein the bottom of the chromium precipitation reaction flow channel has a plurality of wave flow rotation accommodating grooves arranged perpendicular to the flow direction thereof, and the wave flow control mechanism includes a wave flow blocking shaft rotatably connected to the wave flow rotation accommodating groove, and the wave flow blocking shaft has a downstream matching plane;

[0042] A wave flow drive housing is fixed on the outer wall of the chromium precipitation reaction flow channel, the rotating shaft of the wave flow blocking shaft extends into the wave flow drive housing, and a wave flow drive motor for driving the wave flow blocking shaft to rotate is fixed in the wave flow drive housing.

[0043] Description: Under the action of the wave flow control mechanism, the circulation of the chromium-nickel mixed waste liquid in the chromium precipitation reaction flow tank is slowed down, which is conducive to better sedimentation of the precipitate and finally the recovery of the precipitate.

[0044] Preferably, an elution opening and closing control tube is slidably connected in the nickel elution circulation tube, the side wall of the nickel elution circulation tube has a plurality of elution circulation holes penetrating along its radial direction, and the side wall of the elution opening and closing control tube has a plurality of elution opening and closing holes penetrating along its radial direction;

[0045] An opening and closing drive fixed cylinder with an upward opening is fixed at the bottom of the nickel elution circulation tube, an opening and closing drive sliding cylinder with a downward opening is slidably connected inside the opening and closing drive fixed cylinder, and the outer end of the opening and closing drive sliding cylinder is fixedly connected to the elution opening and closing control tube;

[0046] An opening and closing drive telescopic rod is provided in the opening and closing drive fixed cylinder for driving the opening and closing drive sliding cylinder to move up and down;

[0047] A plurality of annular and hollow elution and discharge collecting ring shells are fixed on the outside of the nickel recovery circulation pipe, and an elution and discharge through hole connected to the inside of the elution and discharge collecting ring shell is provided on the side wall of the nickel recovery circulation pipe, and an elution and discharge pipe connected to the inside of the elution and discharge collecting ring shell is fixed on the outside of the elution and discharge collecting ring shell;

[0048] The elution discharge pipe is provided with an elution discharge control valve.

[0049] Description: It adopts an integrated design of adsorption and elution with a compact structure. During the elution process, the eluent passes through the ion exchange resin from the inside out to fully elute the ion exchange resin adsorbed with nickel ions.

[0050] Preferably, a plurality of nickel circulation barrier rings are fixed on the inner side wall of the nickel recovery circulation tube, and the inner side of the nickel circulation barrier ring is tightly fitted with the outer side surface of the ion exchange resin.

[0051] Description: The nickel flow barrier ring can separate the nickel recovery channel into multiple relatively independent segments, so that the chromium-nickel mixed waste liquid stays for a sufficient time during the circulation process to fully contact with the ion exchange resin.

[0052] Preferably, a method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, based on the above-mentioned device for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, comprises the following steps:

[0053] S1. Filtering the chromium-nickel mixed waste liquid:

[0054] The chromium-nickel mixed waste liquid is transported to the inside of the flow pipe of the filter mechanism, and the chromium-nickel mixed waste liquid flows from top to bottom in the flow pipe of the filter mechanism;

[0055] Utilizing multiple filter fixed cone shells to filter the chromium-nickel mixed waste liquid, and separating the particle residue in the chromium-nickel mixed waste liquid;

[0056] S2. Conditioning and treating the chromium-nickel mixed waste liquid:

[0057] Adjusting the pH of the filtered chromium-nickel mixed wastewater to 3-5;

[0058] S3. Perform chromium recovery treatment on the chromium-nickel mixed waste liquid:

[0059] S3-1. Reduction treatment of chromium-nickel mixed wastewater

[0060] The pH-adjusted chromium-nickel mixed waste liquid is transported to a chromium reduction reaction circulation pipe. During the circulation of the chromium-nickel mixed waste liquid in the chromium reduction reaction circulation pipe, a chromium reducing agent is introduced into each reducing agent dosing pipe, and the chromium reducing agent is discharged from each agent dosing nozzle, so that the chromium reducing agent and the chromium-nickel mixed waste liquid are fully mixed.

[0061] S4. Recovering nickel from the chromium-nickel mixed waste liquid:

[0062] S4-1, ion exchange adsorption of chromium-nickel mixed wastewater

[0063] After chromium recovery treatment, the chromium-nickel mixed waste liquid is transported to the nickel recovery circulation pipe. The chromium-nickel mixed waste liquid circulates from bottom to top in the nickel recovery circulation pipe, and the ion exchange resin is used to selectively adsorb nickel ions. During the circulation process, the chromium-nickel mixed waste liquid fully contacts the ion exchange resin, allowing the nickel ion exchange resin to adsorb, while other impurity ions flow out through the nickel recovery output pipe;

[0064] S4-2. Elution treatment of chromium-nickel mixed waste liquid

[0065] When the adsorption capacity of the ion exchange resin reaches 4mmol / g, stop the input of the chromium-nickel mixed waste liquid;

[0066] In the initial state, the elution flow holes and the elution opening and closing holes are dislocated and isolated from each other. When the ion exchange resin needs to be eluted, the inner rod of the opening and closing drive telescopic rod is extended to drive the opening and closing drive sliding cylinder together with the elution opening and closing control tube to move upward, so that each elution flow hole is aligned and connected with the elution opening and closing hole;

[0067] The eluent is input into the nickel elution flow tube, and the eluent passes through the elution flow hole and the elution opening and closing hole and then fully contacts the ion exchange resin, and the ion exchange resin adsorbed with nickel ions is eluted;

[0068] The eluent enters the elution collection ring shell through the elution discharge through hole, and the elution discharge control valve is opened, and the eluent in the elution collection ring shell is discharged through the elution discharge pipe;

[0069] That is, the separate recovery of chromium and nickel in the chromium-nickel mixed waste liquid is realized.

[0070] Compared with the prior art, the beneficial effects of the present invention are embodied in the following aspects:

[0071] 1. The present invention has a reasonable structural design and high separation capacity, which can accurately separate chromium ions and nickel ions from mixed waste liquid, ensuring that the recovered chromium and nickel have high purity. The corresponding ion exchange resin is used to fully separate the chromium ions and nickel ions from other impurity ions to avoid mutual interference;

[0072] 2. The present invention has good adaptability. The chromium-nickel mixed waste liquid generated by the electroplating industry has complex components and may contain other heavy metal ions, organic matter, acids and alkalis and other impurities. The equipment can adapt to such complex composition changes and can stably and effectively recover chromium and nickel when treating various waste liquids.

[0073] 3. The pre-treatment filtration mechanism of the present invention adopts a stepped filter hole arrangement to separate the particle residues in the chromium-nickel mixed waste liquid in batches according to particle size;

[0074] 4. The present invention adopts a conical filter fixed cone shell, so that the intercepted particle residues can be automatically distributed and accumulated on the outer ring of the bottom of the cone structure, avoiding clogging of the filter fixed cone shell, so that the filter device always maintains good filtering performance;

[0075] 5. The present invention utilizes a tail flow driving mechanism to drive the chromium-nickel mixed waste liquid to generate a swirling flow during the circulation process, which is beneficial for the chromium-nickel mixed waste liquid to be fully mixed with the chromium reducing agent;

[0076] 6. The chromium recovery unit of the present invention can convert chromium in the chromium-nickel mixed waste liquid into a precipitate. Under the action of the wave flow control mechanism, the flow of the chromium-nickel mixed waste liquid in the chromium precipitation reaction flow tank is slowed down, which is conducive to better sedimentation of the precipitate, and finally the precipitate is recovered.

[0077] 7. The nickel recovery unit of the present invention adopts an integrated design of adsorption and elution, with a compact structure. The nickel flow barrier ring can divide the nickel recovery channel into multiple relatively independent segments, so that the chromium-nickel mixed waste liquid stays for a sufficient time during the circulation process to fully contact the ion exchange resin. During the elution process, the eluent passes through the ion exchange resin from the inside out, and the ion exchange resin adsorbed with nickel ions is fully eluted. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a schematic diagram of the overall layout of the present invention;

[0079] Figure 2 It is a structural schematic diagram of the pretreatment filtration mechanism of the present invention;

[0080] Figure 3 It is a structural schematic diagram of the filter hole adjustment mechanism of the present invention;

[0081] Figure 4 It is a structural schematic diagram of the chromium reduction reaction mechanism of the present invention;

[0082] Figure 5 This is a schematic structural diagram of the reducing agent dosing pipe of the present invention;

[0083] Figure 6This is a schematic diagram of the cross-sectional structure of the reducing agent dosing pipe of the present invention;

[0084] Figure 7 It is a schematic structural diagram of the chromium precipitation reaction mechanism of the present invention;

[0085] Figure 8 It is a structural schematic diagram of the sedimentation partition barrier mechanism of the present invention;

[0086] Figure 9 It is a left side view of the sedimentation and flushing mechanism of the present invention;

[0087] Figure 10 It is a structural schematic diagram of the wave flow control mechanism of the present invention;

[0088] Figure 11 yes Figure 10 A top view of

[0089] Figure 12 Schematic diagram of the structure of the nickel recovery unit of the present invention;

[0090] Figure 13 It is a structural schematic diagram of the elution opening and closing control tube of the present invention.

[0091] In the figure, 10-pretreatment filter mechanism, 101-filter input pipe, 102-filter output pipe, 103-filter residue collection tank, 104-filter residue external discharge pipe, 1040-filter residue external discharge control valve, 105-regulating tank, 11-filter mechanism circulation pipe, 111-filter shell support ring, 12-filter fixed cone shell, 120-filter leak hole, 13-filter hole adjustment mechanism, 130-filter hole adjustment leak hole, 131-filter hole adjustment cone shell, 132-rotating support ring, 133-rotating support cylinder, 20-chromium recovery unit, 21-chromium reduction reaction mechanism, 211-chromium reduction reaction circulation pipe, 2110-dosing pipe accommodating hole, 212-reducing agent dosing Adding pipe, 2120-agent dosing nozzle, 213-dosing pipe drive housing, 214-dosing pipe drive telescopic rod, 215-chromium reduction reaction static tank, 22-chromium precipitation reaction mechanism, 220-chromium precipitation holding tank, 221-chromium precipitation reaction flow slot, 222-precipitation reaction input pipe, 223-chromium precipitation reaction output pipe, 2230-precipitation output control valve, 224-chromium precipitation recovery pipe, 2240-precipitation recovery control valve, 225-precipitation agent delivery pipe, 2250-precipitation agent nozzle, 23-wave flow control mechanism, 230-wave flow rotation holding tank, 231-wave flow blocking axis, 2310-downstream matching plane, 232 -wave flow drive housing, 233-wave flow drive motor, 30-nickel recovery unit, 31-nickel recovery circulation pipe, 310-nickel recovery channel, 311-nickel recovery input pipe, 312-nickel recovery output pipe, 313-nickel circulation barrier ring, 32-nickel elution circulation pipe, 320-elution circulation hole, 321-nickel elution input pipe, 33-ion exchange resin, 34-elution opening and closing control pipe, 340-elution opening and closing hole, 341-opening and closing drive fixed cylinder, 342-opening and closing drive sliding cylinder, 343-opening and closing drive telescopic rod, 35-elution external discharge collection ring shell, 350-elution external discharge through hole, 351-elution external discharge pipe, 3510-elution external discharge Control valve, 41-wake drive mechanism, 411-wake drive tube shell, 412-wake drive shaft, 413-wake drive blade, 414-wake drive motor, 415-radial guide plate, 42-sedimentation partition barrier mechanism, 420-baffle plate sliding groove, 421-partition barrier, 422-baffle plate drive accommodating shell, 423-baffle plate drive fixed cylinder, 424-baffle plate drive sliding cylinder, 425-baffle plate drive telescopic rod, 43-sedimentation flushing mechanism, 431-sedimentation flushing support slide rail, 432-sedimentation flushing support slider, 433-scouring support plate, 434-sedimentation flushing conveying pipe, 435-sedimentation flushing nozzle. DETAILED DESCRIPTION

[0092] The following combination Figures 1-13The present invention is described in detail. For the convenience of description, the directions mentioned below are defined as follows: the up, down, left, right, front and back directions mentioned below are consistent with the up, down, left, right, front and back directions of the projection relationship of each main view or structural schematic diagram itself.

[0093] Example 1:

[0094] A device and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry, such as Figure 1 As shown, it includes a pre-treatment filtering mechanism 10, a chromium recovery unit 20 and a nickel recovery unit 30 which are sequentially connected;

[0095] like Figure 2 As shown, the pre-treatment filter mechanism 10 includes a filter mechanism flow pipe 11 extending vertically, a plurality of filter housing support rings 111 are fixed in the filter mechanism flow pipe 11, and a filter fixing cone 12 with an opening facing downward is fixed on the filter housing support ring 111;

[0096] The side wall of the filter fixed cone shell 12 is provided with a plurality of filter leak holes 120;

[0097] A filter input pipe 101 is fixed to the top of the filter mechanism flow pipe 11 and is connected to the interior thereof, and a filter output pipe 102 is fixed to the bottom of the filter mechanism flow pipe 11 and is connected to the interior thereof;

[0098] like Figure 2 As shown, a filter residue collection tank 103 is formed between the upper side of the filter housing support ring 111 and the outer side wall of the lower end of the filter fixed cone shell 12. A plurality of filter residue discharge pipes 104 connected to the filter residue collection tank 103 are fixed on the outer side of the filter mechanism flow pipe 11. The filter residue discharge pipe 104 is provided with a filter residue discharge control valve 1040. When a certain amount of particulate residue accumulates in the filter residue collection tank 103, the conveying of the chromium-nickel mixed waste liquid is stopped, and a cleaning liquid is conveyed into the filter mechanism flow pipe 11 through the filter input pipe 101. The cleaning liquid can be clean water. Each filter residue discharge control valve 1040 is opened, and the particulate residue accumulated in the filter residue collection tank 103 is discharged through the filter residue discharge pipe 104 under the flushing action of the cleaning liquid.

[0099] like Figure 1 As shown, the chromium recovery unit 20 includes a chromium reduction reaction mechanism 21 and a chromium precipitation reaction mechanism 22;

[0100] like Figure 4 、 Figure 5 、 Figure 6 As shown, the chromium reduction reaction mechanism 21 includes a chromium reduction reaction flow pipe 211. The side wall of the chromium reduction reaction flow pipe 211 has a plurality of dosing pipe receiving holes 2110 extending radially therethrough. A reducing agent dosing pipe 212 is slidably connected to the dosing pipe receiving holes 2110. A plurality of dosing nozzles 2120 are fixed to the outside of the reducing agent dosing pipe 212 and communicate with the reducing agent dosing pipe 212.

[0101] The filter output pipe 102 is connected to the regulating tank 105, and the input end of the chromium reduction reaction flow pipe 211 is connected to the regulating tank 105;

[0102] A dosing tube drive housing 213 is fixed to the outside of the chromium reduction reaction circulation pipe 211. A dosing tube drive housing 213 is provided inside the dosing tube drive housing 213 for driving the reducing agent dosing tube 212 to move. The dosing tube drive housing 213 is an electrically controlled dosing tube as used in the prior art. The outer end of the dosing tube drive housing 213 is fixedly connected to the dosing tube drive housing 213, and the inner end of the dosing tube drive housing 214 is fixedly connected to the reducing agent dosing tube 212.

[0103] The output end of the chromium reduction reaction flow pipe 211 is connected to the chromium reduction reaction static tank 215;

[0104] like Figure 7 As shown, the chromium precipitation reaction mechanism 22 includes a chromium precipitation holding tank 220, in which a plurality of chromium precipitation reaction flow channels 221 are fixed;

[0105] The input end of the chromium precipitation reaction flow channel 221 is fixed with a precipitation reaction input pipe 222 connected thereto, and the other end of the precipitation reaction input pipe 222 is connected to the chromium reduction reaction static tank 215. The output end of the chromium precipitation reaction flow channel 221 is fixed with a chromium precipitation reaction output pipe 223 and a chromium precipitation recovery pipe 224 connected thereto;

[0106] The chromium precipitation reaction flow channel 221 is arranged at an angle of 1° to the horizontal plane, the higher end of the chromium precipitation reaction flow channel 221 is the input end, and the lower end of the chromium precipitation reaction flow channel 221 is the output end;

[0107] The chromium precipitation reaction output pipe 223 is provided with a precipitation output control valve 2230 , and the chromium precipitation recovery pipe 224 is provided with a precipitation recovery control valve 2240 ;

[0108] A precipitation agent delivery pipe 225 is fixed in the input end of the chromium precipitation reaction flow tank 221, and a plurality of precipitation agent nozzles 2250 are provided on the lower side of the precipitation agent delivery pipe 225;

[0109] like Figure 12 As shown, the nickel recovery unit 30 includes a vertically extending nickel recovery circulation pipe 31, and a nickel elution circulation pipe 32 extending coaxially therewith is fixed in the nickel recovery circulation pipe 31;

[0110] A nickel recovery channel 310 is formed between the inner wall of the nickel recovery circulation tube 31 and the outer wall of the nickel elution circulation tube 32;

[0111] A cylindrical ion exchange resin 33 is fixed on the outer wall of the nickel elution flow tube 32;

[0112] A nickel recovery input pipe 311 is fixed to the lower end of the nickel recovery circulation pipe 31 and is connected to the interior thereof. A nickel recovery output pipe 312 is fixed to the top of the nickel recovery circulation pipe 31 and is connected to the interior thereof.

[0113] The nickel recovery input pipe 311 is connected to the chromium precipitation reaction output pipe 223;

[0114] A nickel elution input pipe 321 connected to the interior of the nickel elution circulation pipe 32 is fixed on the top of the nickel elution circulation pipe 32.

[0115] like Figure 13 As shown, the nickel elution flow tube 32 is slidably connected to the elution opening and closing control tube 34. The side wall of the nickel elution flow tube 32 has a plurality of elution flow holes 320 extending radially therethrough, and the side wall of the elution opening and closing control tube 34 has a plurality of elution opening and closing holes 340 extending radially therethrough.

[0116] A fixed opening and closing drive cylinder 341 with an upward opening is fixed to the bottom of the nickel elution circulation tube 32. A sliding opening and closing drive cylinder 342 with a downward opening is slidably connected to the fixed opening and closing drive cylinder 341. The outer end of the sliding opening and closing drive cylinder 342 is fixedly connected to the elution opening and closing control tube 34.

[0117] An opening and closing drive telescopic rod 343 is provided in the opening and closing drive fixed cylinder 341 for driving the opening and closing drive sliding cylinder 342 to move up and down. The opening and closing drive telescopic rod 343 is an electrically controlled telescopic rod in the prior art. The outer rod end of the opening and closing drive telescopic rod 343 is fixedly connected to the bottom of the opening and closing drive fixed cylinder 341, and the inner rod end of the opening and closing drive telescopic rod 343 is fixedly connected to the top of the opening and closing drive sliding cylinder 342.

[0118] A plurality of annular hollow elution and discharge collecting ring shells 35 are fixed to the outside of the nickel recovery circulation pipe 31. The side wall of the nickel recovery circulation pipe 31 has an elution and discharge through hole 350 connected to the inside of the elution and discharge collecting ring shell 35. An elution and discharge pipe 351 is fixed to the outside of the elution and discharge collecting ring shell 35 and connected to the inside thereof.

[0119] The elution discharge pipe 351 is provided with an elution discharge control valve 3510 .

[0120] like Figure 12 As shown, a plurality of nickel circulation barrier rings 313 are fixed on the inner wall of the nickel recovery circulation pipe 31 , and the inner side of the nickel circulation barrier ring 313 is tightly fitted with the outer side of the ion exchange resin 33 .

[0121] Example 2:

[0122] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, based on the device for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry in Example 1, comprises the following steps:

[0123] S1. Filtering the chromium-nickel mixed waste liquid:

[0124] The chromium-nickel mixed waste liquid is transported to the inside of the filter mechanism flow pipe 11, and the chromium-nickel mixed waste liquid flows from top to bottom in the filter mechanism flow pipe 11;

[0125] Utilizing a plurality of filter fixed cone shells 12 to filter the chromium-nickel mixed waste liquid, and separating the particle residue in the chromium-nickel mixed waste liquid;

[0126] S2. Conditioning and treating the chromium-nickel mixed waste liquid:

[0127] Adjusting the pH of the filtered chromium-nickel mixed wastewater to 3-5;

[0128] S3. Perform chromium recovery treatment on the chromium-nickel mixed waste liquid:

[0129] S3-1. Reduction treatment of chromium-nickel mixed wastewater

[0130] The pH-adjusted chromium-nickel mixed waste liquid is transported to the chromium reduction reaction circulation pipe 211. During the circulation of the chromium-nickel mixed waste liquid in the chromium reduction reaction circulation pipe 211, a chromium reducing agent is introduced into each reducing agent dosing pipe 212. The chromium reducing agent is discharged from each agent dosing nozzle 2120, so that the chromium reducing agent and the chromium-nickel mixed waste liquid are fully mixed.

[0131] The chromium reducing agent is sodium sulfite, which is used to reduce hexavalent chromium to trivalent chromium;

[0132] The sodium sulfite solution is delivered to each reducing agent feeding pipe 212 through a pipeline using a liquid delivery pump of the prior art;

[0133] S3-2, precipitation treatment of chromium-nickel mixed wastewater

[0134] The chromium-nickel mixed waste liquid after the reduction treatment is transported to each chromium precipitation reaction flow tank 221. During the circulation of the chromium-nickel mixed waste liquid in the chromium precipitation reaction flow tank 221, a chromium precipitation agent is introduced into the precipitation agent transport pipe 225. The chromium precipitation agent is discharged from each precipitation agent nozzle 2250, so that the chromium precipitation agent and the chromium-nickel mixed waste liquid are fully mixed.

[0135] The chromium precipitating agent is calcium hydroxide, which reacts with trivalent chromium to form chromium hydroxide precipitate;

[0136] The chromium hydroxide precipitate will be deposited at the bottom of the chromium precipitation reaction flow tank 221, and the excess chromium-nickel mixed waste liquid will be discharged through the chromium precipitation reaction output pipe 223;

[0137] The chromium hydroxide precipitate is put into a high-temperature roasting system to recover chromium in the form of chromium green;

[0138] S4. Recovering nickel from the chromium-nickel mixed waste liquid:

[0139] S4-1, ion exchange adsorption of chromium-nickel mixed wastewater

[0140] After the chromium recovery treatment, the chromium-nickel mixed waste liquid is transported to the nickel recovery circulation pipe 31. The chromium-nickel mixed waste liquid circulates from bottom to top in the nickel recovery circulation pipe 31. The ion exchange resin 33 selectively adsorbs nickel ions. During the circulation process, the chromium-nickel mixed waste liquid fully contacts the ion exchange resin 33, allowing the nickel ion exchange resin 33 to adsorb the nickel ions, while other impurity ions flow out through the nickel recovery output pipe 312.

[0141] The ion exchange resin 33 is a strongly acidic cation exchange resin;

[0142] S4-2. Elution treatment of chromium-nickel mixed waste liquid

[0143] When the adsorption capacity of the ion exchange resin 33 reaches 4 mmol / g, the input of the chromium-nickel mixed waste liquid is stopped;

[0144] In the initial state, the elution flow holes 320 and the elution opening and closing holes 340 are offset and isolated from each other. When the ion exchange resin 33 needs to be eluted, the inner rod of the opening and closing drive telescopic rod 343 is extended to drive the opening and closing drive sliding cylinder 342 and the elution opening and closing control tube 34 to move upward, so that each elution flow hole 320 is aligned and connected with the elution opening and closing hole 340;

[0145] An eluent is introduced into the nickel elution flow tube 32. The eluent passes through the elution flow hole 320 and the elution opening and closing hole 340 and then comes into full contact with the ion exchange resin 33. The ion exchange resin 33 adsorbed with nickel ions is eluted.

[0146] The eluent is sulfuric acid solution;

[0147] The eluent enters the elution collection ring shell 35 through the elution discharge through hole 350, and the elution discharge control valve 3510 is opened, and the eluent in the elution collection ring shell 35 is discharged through the elution discharge pipe 351;

[0148] That is, the separate recovery of chromium and nickel in the chromium-nickel mixed waste liquid is realized.

[0149] Example 3:

[0150] On the basis of Example 1, Figure 3 As shown, a filter hole adjustment mechanism 13 is provided inside the filter fixed cone shell 12. The filter hole adjustment mechanism 13 includes a filter hole adjustment cone shell 131 that is rotatably connected to the inside of the filter fixed cone shell 12.

[0151] The side wall of the filter hole adjustment cone shell 131 is provided with a plurality of filter hole adjustment holes 130 , and the filter hole adjustment holes 130 are connected to each filter hole 120 in a one-to-one correspondence;

[0152] A rotating support ring 132 coaxially arranged with the filter mechanism flow tube 11 is fixed to the top of the filter fixed cone shell 12, and a rotating support cylinder 133 with an upward opening is fixed to the top of the filter hole adjustment cone shell 131. The rotating support cylinder 133 is rotatably connected to the outside of the rotating support ring 132;

[0153] The rotating support cylinder 133 is driven by a conventional servo motor fixed in the rotating support ring 132 through gear transmission to rotate around the vertical axis of the filter mechanism flow tube 11.

[0154] Example 4:

[0155] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry is based on the apparatus for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry in Example 3. The method differs from Example 2 in that, in step S1, a filter hole adjustment mechanism 13 is used to adjust the filter holes 120 on each filter fixed cone shell 12, so that the filter holes 120 on each filter fixed cone shell 12 arranged from top to bottom are successively reduced in size, thereby separating particulate residues in the chromium-nickel mixed waste liquid in batches according to particle size.

[0156] The rotating support cylinder 133 is driven by a prior art servo motor fixed in the rotating support ring 132 through gear transmission to rotate around the vertical axis of the filter mechanism flow tube 11;

[0157] The rotating support cylinder 133 drives the filter hole adjustment cone shell 131 to rotate together, so that the filter hole adjustment holes 130 correspond one-to-one to each filter hole 120 and are offset to adjust the size of the intersection channel between the filter hole adjustment holes 130 and the filter hole adjustment holes 130.

[0158] Example 5:

[0159] On the basis of Example 3, Figure 4 As shown, a wake drive mechanism 41 is provided in the chromium reduction reaction flow pipe 211. The wake drive mechanism 41 includes a wake drive tube housing 411 coaxially fixed in the chromium reduction reaction flow pipe 211. A wake drive shaft 412 is rotatably connected to the backwater end of the wake drive tube housing 411. A plurality of wake drive blades 413 are fixed to the wake drive shaft 412.

[0160] A wake drive motor 414 is fixed in the wake drive housing 411 for driving the wake drive shaft 412 to rotate;

[0161] The wake drive motor 414 is a motor of the prior art, and the wake drive motor 414 drives the wake drive shaft 412 to rotate through gear transmission;

[0162] The wake driving pipe shell 411 is fixedly connected to the inner wall of the chromium reduction reaction flow pipe 211 through multiple radial guide plates 415;

[0163] The radial guide plate 415 is extended along the radial plane of the chromium reduction reaction flow tube 211 .

[0164] Example 6:

[0165] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry is based on the apparatus for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry in Example 5, and differs from Example 4 in that, in step S3-1, a tail flow driving mechanism 41 is used to drive the chromium-nickel mixed waste liquid to generate a swirling flow during circulation to fully mix it with a chromium reducing agent.

[0166] The wake drive motor 414 drives the wake drive shaft 412 to rotate, and the wake drive shaft 412 drives the multiple wake drive blades 413 to stir the chromium-nickel mixed waste liquid flowing in the chromium reduction reaction circulation pipe 211, so that the chromium reducing agent and the chromium-nickel mixed waste liquid are fully mixed.

[0167] Example 7:

[0168] On the basis of Example 5, Figure 7 As shown, a precipitation partition barrier mechanism 42 is provided at the bottom of the chromium precipitation reaction flow channel 221. Figure 8 As shown, the bottom of the chromium precipitation reaction flow channel 221 has a plurality of vertically penetrating barrier plate sliding grooves 420, and the precipitation partitioning barrier mechanism 42 includes partitioning barrier plates 421 slidably connected in the barrier plate sliding grooves 420;

[0169] The plane of the partition baffle 421 is perpendicular to the flow direction of the waste liquid in the chromium precipitation reaction flow channel 221;

[0170] A barrier plate drive housing 422 is fixed to the bottom of the chromium precipitation reaction flow channel 221 at the barrier plate sliding groove 420. A barrier plate drive fixed cylinder 423 with an upward opening is fixed in the barrier plate drive housing 422. A barrier plate drive sliding cylinder 424 with a downward opening is slidably connected in the barrier plate drive fixed cylinder 423. The outer end of the barrier plate drive sliding cylinder 424 is fixedly connected to the lower end of the partition barrier plate 421.

[0171] A barrier plate driving telescopic rod 425 is provided in the barrier plate driving fixed cylinder 423 for driving the barrier plate driving sliding cylinder 424 to move up and down. The barrier plate driving telescopic rod 425 is an electrically controlled telescopic rod of the prior art. The outer rod end of the barrier plate driving telescopic rod 425 is fixedly connected to the bottom of the barrier plate driving fixed cylinder 423, and the inner stem end of the barrier plate driving telescopic rod 425 is fixedly connected to the top of the barrier plate driving sliding cylinder 424.

[0172] Example 8:

[0173] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, and an equipment for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry based on the above-mentioned embodiment 7, which differs from embodiment 6 in that in step S3-2, the chromium hydroxide precipitate is intercepted by a precipitation partitioning barrier mechanism 42. In the initial state, the top of the partitioning barrier plate 421 is flush with the bottom of the chromium precipitation reaction flow channel 221. When the chromium hydroxide precipitate needs to be intercepted, the inner rod of the barrier plate driving the telescopic rod 425 is extended to drive the barrier plate driving the sliding cylinder 424 to move upward together with the partitioning barrier plate 421, so that the partitioning barrier plate 421 is blocked in the chromium precipitation reaction flow channel 221. The chromium hydroxide precipitate accumulates at the bottom of the chromium precipitation reaction flow channel 221 under the action of its own weight and is blocked and intercepted by the partitioning barrier plate 421.

[0174] Example 9:

[0175] On the basis of Example 7, Figure 1 As shown, a precipitation flushing mechanism 43 is provided on the top of the chromium precipitation reaction flow tank 221. Figure 9 As shown, the precipitation and flushing mechanism 43 includes a precipitation and flushing support rail 431 fixed to the top of the chromium precipitation reaction flow channel 221. A precipitation and flushing support slider 432 is slidably connected to the precipitation and flushing support rail 431. A flushing support plate 433 is fixed to the precipitation and flushing support slider 432. A plurality of precipitation and flushing delivery pipes 434 are fixed to the lower side of the flushing support plate 433. The lower side of the precipitation and flushing delivery pipe 434 has a plurality of precipitation and flushing nozzles 435 connected to the interior thereof.

[0176] The precipitation and scouring support rail 431 is arranged to extend parallel to the flow direction of the chromium precipitation reaction flow channel 221, and the precipitation and scouring support slider 432 is driven by a servo motor of the prior art through a gear rack transmission to move along the precipitation and scouring support rail 431;

[0177] Clean water is introduced into each sedimentation flushing delivery pipe 434 using a delivery pump according to the existing technology. Clean water is ejected from each sedimentation flushing nozzle 435 and the sediment inside the chromium precipitation reaction flow tank 221 is flushed and recovered using the impact water flow.

[0178] Example 10:

[0179] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry is based on the apparatus for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry described in Example 9. The method differs from Example 8 in that, in step S3-2, after a certain amount of chromium hydroxide precipitate is intercepted by the partition baffle 421, the intercepted chromium hydroxide precipitate is recovered by the precipitate flushing mechanism 43.

[0180] First, stop feeding the chromium-nickel mixed waste liquid into the chromium precipitation reaction flow channel 221 and close the precipitation output control valve 2230. Then, retract the inner rod of the baffle plate drive telescopic rod 425, driving the baffle plate drive sliding cylinder 424 and the partition baffle plate 421 downward, so that the top of the partition baffle plate 421 is flush with the bottom of the chromium precipitation reaction flow channel 221.

[0181] Clean water is introduced into each precipitation flushing conveying pipe 434, and the clean water is sprayed out from each precipitation flushing nozzle 435 to flush the chromium hydroxide precipitate accumulated in the chromium precipitation reaction circulation groove 221. The precipitation flushing support slider 432 is driven by the servo motor to reciprocate along the precipitation flushing support slide rail 431 to fully flush the chromium hydroxide precipitate in the chromium precipitation reaction circulation groove 221. The precipitation recovery control valve 2240 is opened, and the chromium hydroxide precipitate is discharged from the chromium precipitation recovery pipe 224 under the flushing and carrying of clean water, thereby realizing the recovery of the chromium hydroxide precipitate.

[0182] Example 11:

[0183] On the basis of Example 9, Figure 7 As shown, a wave flow control mechanism 23 is provided at the bottom of the chromium precipitation reaction flow tank 221. Figure 10 、 Figure 11 As shown, the bottom of the chromium precipitation reaction flow channel 221 has a plurality of wave flow rotation accommodating grooves 230 arranged perpendicular to the flow direction thereof. The wave flow control mechanism 23 includes a wave flow blocking shaft 231 rotatably connected to the wave flow rotation accommodating groove 230. The wave flow blocking shaft 231 has a downstream matching surface 2310.

[0184] A wave flow drive housing 232 is fixed to the outer wall of the chromium precipitation reaction flow channel 221. The rotation axis of the wave flow blocking shaft 231 extends into the wave flow drive housing 232. A wave flow drive motor 233 is fixed in the wave flow drive housing 232 for driving the wave flow blocking shaft 231 to rotate.

[0185] The wave-flow driving motor 233 is a servo motor in the prior art, and the output shaft of the wave-flow driving motor 233 is connected to the rotation of the wave-flow blocking shaft 231 through gear transmission.

[0186] Example 12:

[0187] A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, and an equipment for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry based on the above-mentioned embodiment 11, which differs from embodiment 10 in that the wave flow control mechanism 23 is used in step S3-2 to slow down the flow rate of the chromium-nickel mixed waste liquid, thereby facilitating better sedimentation of the chromium hydroxide precipitate. In the initial state, the downstream matching plane 2310 is flush with the bottom of the chromium precipitation reaction flow tank 221, and then the wave flow blocking shaft 231 is rotated under the drive of the wave flow drive motor 233, so that the convex side of the wave flow blocking shaft 231 faces upward in the chromium precipitation reaction flow tank 221, thereby slowing down the circulation of the chromium-nickel mixed waste liquid and facilitating better sedimentation of the chromium hydroxide precipitate.

Claims

1. An apparatus and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry, characterized in that: It comprises a pre-treatment filtering mechanism (10), a chromium recovery unit (20) and a nickel recovery unit (30) which are sequentially connected and arranged; The pre-treatment filter mechanism (10) comprises a filter mechanism flow pipe (11) extending vertically, a plurality of filter housing support rings (111) being fixed in the filter mechanism flow pipe (11), and a filter fixing cone (12) with an opening facing downward being fixed on the filter housing support ring (111); The side wall of the filter fixed cone shell (12) is provided with a plurality of filter leak holes (120); A filter input pipe (101) communicating with the interior of the filter mechanism circulation pipe (11) is fixed to the top of the filter mechanism circulation pipe (11), and a filter output pipe (102) communicating with the interior of the filter mechanism circulation pipe (11) is fixed to the bottom of the filter mechanism circulation pipe (11); The filter output pipe (102) is connected to the regulating tank (105), and the input end of the chromium reduction reaction flow pipe (211) is connected to the regulating tank (105); A filter residue collection groove (103) is formed between the upper side of the filter housing support ring (111) and the outer side wall of the lower end of the filter fixed cone housing (12); a plurality of filter residue discharge pipes (104) connected to the filter residue collection groove (103) are fixed to the outside of the filter mechanism flow pipe (11); and a filter residue discharge control valve (1040) is provided on the filter residue discharge pipe (104); A filter hole adjustment mechanism (13) is provided on the inner side of the filter fixed cone shell (12), and the filter hole adjustment mechanism (13) comprises a filter hole adjustment cone shell (131) rotatably connected to the inner side of the filter fixed cone shell (12); The side wall of the filter hole adjustment cone shell (131) is provided with a plurality of filter hole adjustment leak holes (130), and the filter hole adjustment leak holes (130) are connected to each of the filter leak holes (120) in a one-to-one correspondence; A rotating support ring (132) coaxially arranged with the filter mechanism flow pipe (11) is fixed to the top of the filter fixed cone shell (12); a rotating support cylinder (133) with an upward opening is fixed to the top of the filter hole adjustment cone shell (131); the rotating support cylinder (133) is rotatably connected to the outside of the rotating support ring (132); The chromium recovery unit (20) includes a chromium reduction reaction mechanism (21) and a chromium precipitation reaction mechanism (22); The chromium reduction reaction mechanism (21) comprises a chromium reduction reaction circulation pipe (211) connected to the pretreatment filtering mechanism (10); a plurality of dosing pipe accommodating holes (2110) extending radially through the side wall of the chromium reduction reaction circulation pipe (211); a reducing agent dosing pipe (212) is slidably connected within the dosing pipe accommodating holes (2110); and a plurality of agent dosing nozzles (2120) communicating with the reducing agent dosing pipe (212) are fixed to the outside of the reducing agent dosing pipe (212); A dosing tube drive housing (213) is fixed on the outside of the chromium reduction reaction circulation pipe (211), and a dosing tube drive telescopic rod (214) for driving the reducing agent dosing pipe (212) to move is provided in the dosing tube drive housing (213); The output end of the chromium reduction reaction circulation pipe (211) is connected to a chromium reduction reaction static tank (215); The chromium precipitation reaction mechanism (22) comprises a chromium precipitation holding tank (220), wherein a plurality of chromium precipitation reaction flow channels (221) are fixed in the chromium precipitation holding tank (220); The input end of the chromium precipitation reaction flow channel (221) is fixed with a precipitation reaction input pipe (222) connected thereto, the other end of the precipitation reaction input pipe (222) is connected to the chromium reduction reaction static pool (215), and the output end of the chromium precipitation reaction flow channel (221) is fixed with a chromium precipitation reaction output pipe (223) and a chromium precipitation recovery pipe (224) connected thereto; A precipitation agent delivery pipe (225) is fixed in the input end of the chromium precipitation reaction flow channel (221), and a plurality of precipitation agent nozzles (2250) are provided on the lower side of the precipitation agent delivery pipe (225); A precipitation partitioning barrier mechanism (42) is provided at the bottom of the chromium precipitation reaction flow channel (221). The bottom of the chromium precipitation reaction flow channel (221) has a plurality of vertically penetrating barrier plate sliding grooves (420). The precipitation partitioning barrier mechanism (42) includes a partitioning barrier plate (421) slidably connected within the barrier plate sliding grooves (420). A baffle plate drive housing (422) is fixed to the bottom of the chromium precipitation reaction flow channel (221) at the baffle plate sliding groove (420), a baffle plate drive fixed cylinder (423) with an upward opening is fixed in the baffle plate drive housing (422), a baffle plate drive sliding cylinder (424) with a downward opening is slidably connected in the baffle plate drive fixed cylinder (423), and the outer end of the baffle plate drive sliding cylinder (424) is fixedly connected to the lower end of the partition baffle plate (421); A blocking plate driving telescopic rod (425) for driving the blocking plate driving sliding cylinder (424) to move upward and downward is provided in the blocking plate driving fixed cylinder (423); The nickel recovery unit (30) comprises a vertically extending nickel recovery circulation pipe (31), wherein a nickel elution circulation pipe (32) extending coaxially therewith is fixed in the nickel recovery circulation pipe (31); A nickel recovery channel (310) is formed between the inner wall of the nickel recovery circulation tube (31) and the outer wall of the nickel elution circulation tube (32); A cylindrical ion exchange resin (33) is fixed on the outer wall of the nickel elution circulation tube (32); A nickel recovery input pipe (311) connected to the interior of the nickel recovery circulation pipe (31) is fixed at the lower end thereof, and a nickel recovery output pipe (312) connected to the interior thereof is fixed at the top of the nickel recovery circulation pipe (31); The nickel recovery input pipe (311) is connected to the chromium precipitation reaction output pipe (223); A nickel elution input pipe (321) is fixed on the top of the nickel elution circulation pipe (32) and is connected to the inside of the nickel elution circulation pipe (32); An elution opening and closing control tube (34) is slidably connected to the nickel elution circulation tube (32), a side wall of the nickel elution circulation tube (32) has a plurality of elution circulation holes (320) extending radially therethrough, and a side wall of the elution opening and closing control tube (34) has a plurality of elution opening and closing holes (340) extending radially therethrough. An opening and closing driving fixed cylinder (341) with an opening facing upward is fixed to the bottom of the nickel elution circulation tube (32), an opening and closing driving sliding cylinder (342) with an opening facing downward is slidably connected to the opening and closing driving fixed cylinder (341), and the outer end of the opening and closing driving sliding cylinder (342) is fixedly connected to the elution opening and closing control tube (34); An opening and closing driving telescopic rod (343) for driving the opening and closing driving sliding cylinder (342) to move upward and downward is provided in the opening and closing driving fixed cylinder (341); A plurality of annular hollow elution and discharge collecting ring shells (35) are fixed on the outside of the nickel recovery circulation pipe (31); an elution and discharge through hole (350) communicating with the inside of the elution and discharge collecting ring shell (35) is provided on the side wall of the nickel recovery circulation pipe (31); and an elution and discharge pipe (351) communicating with the inside of the elution and discharge collecting ring shell (35) is fixed on the outside of the elution and discharge collecting ring shell (35); The elution discharge pipe (351) is provided with an elution discharge control valve (3510).

2. The device and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry according to claim 1 is characterized in that: A wake drive mechanism (41) is provided in the chromium reduction reaction circulation tube (211), the wake drive mechanism (41) comprising a wake drive tube shell (411) coaxially fixed in the chromium reduction reaction circulation tube (211), a wake drive shaft (412) being rotatably connected to a backwater end of the wake drive tube shell (411), and a plurality of wake drive blades (413) being fixed to the wake drive shaft (412); A wake drive motor (414) for driving the wake drive shaft (412) to rotate is fixed in the wake drive tube housing (411); The wake drive tube shell (411) is fixedly connected to the inner wall of the chromium reduction reaction circulation tube (211) via a plurality of radial guide plates (415).

3. The device and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry according to claim 1, characterized in that: A precipitation flushing mechanism (43) is provided on the top of the chromium precipitation reaction flow channel (221), and the precipitation flushing mechanism (43) includes a precipitation flushing support slide rail (431) fixed on the top of the chromium precipitation reaction flow channel (221), a precipitation flushing support slider (432) is slidably connected to the precipitation flushing support slide rail (431), a flushing support plate (433) is fixed on the precipitation flushing support slider (432), and a plurality of precipitation flushing delivery pipes (434) are fixed on the lower side of the flushing support plate (433), and a plurality of precipitation flushing nozzles (435) are connected to the interior of the precipitation flushing delivery pipe (434) on the lower side.

4. The device and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry according to claim 1, characterized in that: The bottom of the chromium precipitation reaction flow channel (221) is provided with a wave flow control mechanism (23), the bottom of the chromium precipitation reaction flow channel (221) has a plurality of wave flow rotation accommodating grooves (230) arranged perpendicular to the flow direction thereof, the wave flow control mechanism (23) includes a wave flow blocking shaft (231) rotatably connected to the wave flow rotation accommodating groove (230), and the wave flow blocking shaft (231) has a downstream matching plane (2310); A wave flow drive housing (232) is fixed to the outer wall of the chromium precipitation reaction flow channel (221), a rotating shaft of the wave flow blocking shaft (231) extends into the wave flow drive housing (232), and a wave flow drive motor (233) for driving the wave flow blocking shaft (231) to rotate is fixed in the wave flow drive housing (232).

5. The device and method for cascade recovery of chromium-nickel mixed waste liquid in electroplating industry according to claim 1 is characterized in that: A plurality of nickel circulation barrier rings (313) are fixed on the inner wall of the nickel recovery circulation pipe (31), and the inner sides of the nickel circulation barrier rings (313) are tightly fitted with the outer sides of the ion exchange resin (33).

6. A method for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry, based on the device for cascade recovery of chromium-nickel mixed waste liquid in the electroplating industry according to claim 1, characterized in that: The following steps are involved: S1. Filtering the chromium-nickel mixed waste liquid: The chromium-nickel mixed waste liquid is transported to a pre-treatment filtering mechanism (10), the chromium-nickel mixed waste liquid is filtered, and the particulate residue in the chromium-nickel mixed waste liquid is separated; S2. Conditioning and treating the chromium-nickel mixed waste liquid: Adjust the pH of the filtered chromium-nickel mixed wastewater to 3-5; S3. Perform chromium recovery treatment on the chromium-nickel mixed waste liquid: S3-1. Reduction treatment of chromium-nickel mixed waste liquid The pH-adjusted chromium-nickel mixed waste liquid is transported to the chromium reduction reaction circulation pipe (211). During the circulation of the chromium-nickel mixed waste liquid in the chromium reduction reaction circulation pipe (211), a chromium reducing agent is introduced into each reducing agent dosing pipe (212). The chromium reducing agent is discharged from each agent dosing nozzle (2120), so that the chromium reducing agent and the chromium-nickel mixed waste liquid are fully mixed. S3-2, precipitation treatment of chromium-nickel mixed wastewater The chromium-nickel mixed waste liquid after the reduction treatment is transported to each chromium precipitation reaction circulation tank (221). During the circulation of the chromium-nickel mixed waste liquid in the chromium precipitation reaction circulation tank (221), a chromium precipitation agent is introduced into the precipitation agent transport pipe (225). The chromium precipitation agent is discharged from each precipitation agent nozzle (2250), so that the chromium precipitation agent and the chromium-nickel mixed waste liquid are fully mixed. S4. Recovering nickel from the chromium-nickel mixed waste liquid: S4-1, ion exchange adsorption of chromium-nickel mixed wastewater After the chromium recovery treatment, the chromium-nickel mixed waste liquid is transported to the nickel recovery circulation pipe (31). The chromium-nickel mixed waste liquid circulates from bottom to top in the nickel recovery circulation pipe (31). The ion exchange resin (33) is used to selectively adsorb nickel ions. The chromium-nickel mixed waste liquid is fully contacted with the ion exchange resin (33) during the circulation process, so that the nickel ion exchange resin (33) adsorbs the nickel, while other impurity ions flow out through the nickel recovery output pipe (312). S4-2. Elution treatment of chromium-nickel mixed waste liquid When the adsorption capacity of the ion exchange resin (33) reaches 4 mmol / g, the input of the chromium-nickel mixed waste liquid is stopped; In the initial state, the elution flow holes (320) and the elution opening and closing holes (340) are dislocated and isolated from each other. When the ion exchange resin (33) needs to be eluted, the inner rod of the opening and closing driving telescopic rod (343) is extended to drive the opening and closing driving sliding cylinder (342) together with the elution opening and closing control tube (34) to move upward, so that each elution flow hole (320) is aligned and connected with the elution opening and closing hole (340); An eluent is input into the nickel elution flow tube (32), and the eluent passes through the elution flow hole (320) and the elution opening and closing hole (340) and then fully contacts the ion exchange resin (33), and the ion exchange resin (33) adsorbed with nickel ions is eluted; The eluent enters the interior of the elution discharge collecting ring shell (35) through the elution discharge through hole (350), and the elution discharge control valve (3510) is opened, and the eluent in the elution discharge collecting ring shell (35) is discharged through the elution discharge pipe (351); That is, the separate recovery of chromium and nickel in the chromium-nickel mixed waste liquid is realized.

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