Sewage treatment device with metal recovery function

Abstract

The application discloses a sewage treatment device with metal recovery function, and belongs to the technical field of sewage treatment, which comprises a treatment cylinder, an upper end cover and a lower end cover, a support is arranged at the bottom of the upper end cover, an electrolytic flow field balancing assembly is arranged on the outer side wall of the support, a plurality of electrolytic crystallization modules are arranged in the electrolytic flow field balancing assembly, and a collecting port is arranged at the bottom of the lower end cover. The electrolytic crystallization modules are arranged, so that nickel ions grow into metal crystals on the surface of the cathode spindle-shaped titanium column and are stripped through a stripping plate, high-purity solid metal nickel can be obtained and is directly used for metallurgical recovery, the residence time of sewage is prolonged through the arrangement of a spiral flow channel, the liquid outlet is arranged at a position lower than the outlet of the spiral flow channel, a precipitation cavity is formed at the lower part of the treatment cylinder, the nickel crystals after stripping settle at the bottom of the precipitation cavity, and supernatant is continuously overflowed and discharged, so that the synchronous and continuous operation of electrolytic crystallization, stripping, solid-liquid separation and water discharge is realized.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater treatment device with metal recovery function. Background Technology

[0002] Nickel electroplating is a common surface treatment process in industrial production. The nickel-containing wastewater generated during the electroplating process is a source of heavy metal pollution. Therefore, nickel-containing wastewater needs to be treated before it can be discharged. Since nickel has recycling value, the existing treatment methods for nickel-containing electroplating wastewater include wastewater purification and nickel resource recovery. Nickel resource recovery includes chemical precipitation, adsorption, ion exchange and membrane separation methods.

[0003] Chemical precipitation methods (such as adding sodium hydroxide, sodium sulfide, etc. to form nickel hydroxide or sulfide precipitates) will produce a large amount of chemical sludge containing heavy metals. Nickel is mixed in the sludge in the form of compounds, resulting in low purity of resource recovery and high subsequent disposal costs. Adsorption and ion exchange methods can enrich nickel to a certain extent, but the regeneration process of adsorbents or resins will produce high-concentration eluent, which still needs further treatment. Membrane separation can achieve water reuse and nickel concentration, but there is a problem of membrane fouling, and the concentrate also needs further treatment.

[0004] Existing electrolytic recovery equipment is mostly a tank-type electrolytic device, which can only recover metallic nickel in the wastewater in its own electrolytic cell at the same time. After each recovery is completed, the deposits attached to the cathode plate need to be cleaned manually or mechanically before it can work again. Not only is the processing capacity small, but it also cannot operate continuously.

[0005] Therefore, a wastewater treatment device with metal recovery function is proposed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to solve the problems in the prior art where nickel is mixed in the sludge in the form of compounds in nickel electroplating wastewater treatment devices, making resource recovery difficult, and the need for intermittent shutdowns during the electrolytic recovery process. Therefore, this invention proposes a wastewater treatment device with metal recovery function.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A wastewater treatment device with metal recovery function includes a treatment cylinder. The upper and lower ends of the treatment cylinder are respectively provided with an upper end cover and a lower end cover. The bottom of the upper end cover is provided with a support column. An electrolytic flow field equalization component is provided on the outer wall of the support column. The electrolytic flow field equalization component is provided with multiple electrocrystallization modules. The bottom of the lower end cover is provided with a collection port for discharging the recovered nickel metal.

[0009] The electrolysis flow field balancing assembly comprises an upper spiral plate and a lower spiral plate, a gap between the upper spiral plate and the lower spiral plate forms a spiral flow channel, and the upper spiral plate and the lower spiral plate are both provided with a plurality of sector planes parallel to a horizontal plane, and the sector planes are provided with mounting ports for mounting the electrocrystallization modules.

[0010] The electrocrystallization module comprises an anode box mounted on the upper spiral plate and a cathode box mounted on the lower spiral plate, the anode box is provided below with a stripping assembly, and the cathode box is provided above with a nickel crystallization growth zone, and the nickel crystallization growth zone is composed of a plurality of titanium columns.

[0011] Preferably, the upper end cover is provided at the top with a cable and a liquid inlet pipe, and the output end of the liquid inlet pipe is communicated with the input end of the spiral flow channel.

[0012] Preferably, a wire passing hole is formed in the support column, so that the lead wire of the electrocrystallization module can be connected with the control system through the wire passing hole and the cable.

[0013] Preferably, the titanium column is in a spindle shape, the surface of the titanium column is provided with a roughening layer processed by a sand blasting process, and the titanium column is provided with a steel core.

[0014] Preferably, the anode box is provided with a stripping push cylinder, a stripping plate is mounted on the piston rod of the stripping push cylinder and penetrates through the anode box, a stripping hole corresponding to the titanium column is formed in the stripping plate, and the bottom of the anode box is provided with an anode plate for forming an electrolysis electric field to guide the growth of nickel crystals.

[0015] Preferably, a rubber stripping sleeve is arranged in the stripping hole, and the rubber stripping sleeve is tightly attached to the surface of the spindle-shaped titanium column by utilizing the elastic expansion characteristics of rubber, and the nickel crystals on the surface of the titanium column are stripped during the lifting operation.

[0016] Preferably, the surface of the cathode box is provided with a mounting plate, the mounting plate is provided with a threaded groove matched with the titanium column as a cathode contact, and the threaded groove is connected with the steel core.

[0017] Preferably, a liquid discharge port is mounted on the outer side wall of the processing cylinder, the height of the liquid discharge port is lower than the outlet of the spiral flow channel, so that a precipitation cavity is formed below the liquid discharge port and above the collection port, and the precipitation cavity is used for separating the nickel crystals stripped by the stripping assembly from sewage.

[0018] Preferably, a plurality of the electrocrystallization modules are arranged along the flow direction of the sewage, and the current density in the electrocrystallization modules is arranged in a gradient decreasing manner, so as to match the attenuation of the ion concentration in the sewage along the spiral flow channel.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. The nickel ions in the sewage are reduced on the surface of the spindle-shaped titanium column as a cathode and grow in the form of metal crystals by setting the electrocrystallization module, and after the nickel metal crystals are stripped by the stripping plate, the solid metal nickel in the form of sheets, blocks and powders can be obtained, the product has high purity and can be directly recycled as a metallurgical raw material.

[0021] 2. The residence time of the sewage is greatly prolonged by the cooperation of the spiral flow channel and the drainage port, the drainage port is arranged at a position lower than the outlet of the spiral flow channel, so that a sedimentation cavity is formed at the bottom of the treatment cylinder, the stripped nickel crystals fall into the sedimentation cavity and quickly settle at the bottom of the sedimentation cavity due to the large density, and the supernatant of the sewage continuously overflows from the drainage port, so that the processes of electrolytic crystallization, stripping, solid-liquid separation and water discharge can be carried out synchronously, and the function of uninterrupted work is realized.

[0022] 3. The multiple electrocrystallization modules are arranged along the flow direction, and an independent control unit is configured for each module, the modules located in the front section of the flow channel are driven by a high current density to quickly capture a large amount of nickel ions, and the modules located in the middle and rear sections of the flow channel gradually reduce the current density to match the electrochemical kinetics conditions under low concentration, so that the residual ions are deeply removed, the energy is saved under the premise of ensuring the recovery rate, and excessive electrolysis at the end is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 An external structure schematic view of a sewage treatment device with metal recovery function is provided for the present application;

[0024] Figure 2 An internal structure sectional view of a sewage treatment device with metal recovery function is provided for the present application;

[0025] Figure 3 A structure assembly drawing of a sewage treatment device with metal recovery function is provided for the present application;

[0026] Figure 4 A local structure schematic view of an electrolytic flow field balancing assembly in a sewage treatment device with metal recovery function is provided for the present application;

[0027] Figure 5 A structure assembly drawing of an anode box and a cathode box and a fan-shaped plane in a sewage treatment device with metal recovery function is provided for the present application;

[0028] Figure 6 An internal structure sectional view of an anode box in a sewage treatment device with metal recovery function is provided for the present application;

[0029] Figure 7A structure assembly view of a middle stripping plate and a rubber stripping sleeve of a sewage treatment device with metal recovery function according to the present application;

[0030] Figure 8 A structure schematic view of a middle stripping plate and a cathode box of a sewage treatment device with metal recovery function according to the present application when performing a crystallization process;

[0031] Figure 9 A structure assembly view of a cathode box and a titanium column of a sewage treatment device with metal recovery function according to the present application;

[0032] Figure 10 An internal structure sectional view of a titanium column of a sewage treatment device with metal recovery function according to the present application.

[0033] In the figure: 1, treatment cylinder; 101, upper end cover; 102, lower end cover; 2, support column; 3, collection port; 4, upper spiral plate; 5, lower spiral plate; 6, fan-shaped plane; 7, spiral flow channel; 8, anode box; 801, anode plate; 9, cathode box; 10, titanium column; 11, liquid inlet pipe; 12, steel core; 13, stripping push cylinder; 14, stripping plate; 15, rubber stripping sleeve; 16, mounting plate; 17, liquid outlet. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom end" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Example, refer to Figures 1 to 10 A wastewater treatment device with metal recovery function includes a treatment cylinder 1. The upper end cover 101 and the lower end cover 102 are respectively provided at the upper and lower ends of the treatment cylinder 1. The bottom of the upper end cover 101 is provided with a support column 2. The outer wall of the support column 2 is provided with an electrolytic flow field equalization component. The electrolytic flow field equalization component is provided with multiple electrocrystallization modules. The bottom of the lower end cover 102 is provided with a collection port 3 for discharging the recovered nickel metal.

[0038] The electrolysis flow field equalization component includes an upper spiral plate 4 and a lower spiral plate 5. The gap between the upper spiral plate 4 and the lower spiral plate 5 forms a spiral flow channel 7 to prolong the residence and reaction time of wastewater and make the fluid distribution of wastewater more uniform. The surfaces of the upper spiral plate 4 and the lower spiral plate 5 are provided with fan-shaped planes 6 parallel to the horizontal plane. The fan-shaped planes 6 are provided with mounting ports for installing electrocrystallization modules.

[0039] The electrocrystallization module includes an anode box 8 mounted on an upper spiral plate 4 and a cathode box 9 mounted on a lower spiral plate 5. A stripping assembly is provided below the anode box 8, and a nickel crystal growth area is provided above the cathode box 9. The nickel crystal growth area is composed of multiple titanium pillars 10.

[0040] The further advantage of the above method is that nickel ions are reduced on the surface of the titanium column 10, which serves as the cathode, through electrolysis and grow in the form of metal crystals. After mechanical stripping and settling, the solid metallic nickel obtained from the collection port 3 is in the form of blocks or flakes. There is no need to add flocculants, precipitants, or other chemical agents. Nickel will not be mixed in the sludge in the form of hydroxides, etc., and can be directly reused for smelting.

[0041] Furthermore, the top of the upper cover 101 is provided with a cable and an inlet pipe 11, and the output end of the inlet pipe 11 is connected to the input end of the spiral flow channel 7.

[0042] Furthermore, the support column 2 is provided with a wiring through hole, so that the wires of the electrocrystallization module can be connected to the control system through the wiring through hole and the cable;

[0043] Furthermore, the titanium pillar 10 is spindle-shaped, and the surface of the titanium pillar 10 is provided with a roughened layer with micro-layers processed by sandblasting. The roughened layer increases the specific surface area and surface energy of the titanium pillar 10, providing more nucleation sites for nickel ions and achieving the effect of accelerating crystallization. The titanium pillar 10 is provided with a steel core 12 to increase structural strength.

[0044] The further advantage of the above is that the spindle-shaped titanium column 10 has the characteristics of being thin at both ends and thick in the middle. When sewage flows along the spiral channel 7 to flush the titanium column 10, it can guide the water flow to smoothly bypass the column and reduce the ion-depleted area caused by the eddy current behind the column, so that nickel ions can migrate more evenly to the entire surface of the column, and nickel crystals can grow stably and evenly on all parts of the column surface.

[0045] Furthermore, the anode box 8 is provided with a stripping push cylinder 13. The piston rod of the stripping push cylinder 13 passes through the anode box 8 and a stripping plate 14 is installed. The stripping plate 14 has stripping holes that correspond one-to-one with the titanium pillars 10. The bottom of the anode box 8 is provided with an anode plate 801, which is used to form an electrolytic electric field to guide the growth of nickel crystals. A rubber stripping sleeve 15 is provided in the stripping hole. It uses the elastic expansion property of rubber to tightly fit the surface of the spindle-shaped titanium pillars 10 and strips the nickel crystals on the surface of the titanium pillars 10 during the lifting and lowering action. When the nickel crystals grow to a predetermined thickness, the stripping push cylinder 13 pushes the stripping plate 14 downward and removes the nickel crystals through the rubber stripping sleeve 15.

[0046] Furthermore, the cathode box 9 is provided with a mounting plate 16 on its surface, and the mounting plate 16 is provided with a threaded groove matching the titanium pillar 10 as a cathode contact, and the threaded groove is connected to the steel core 12.

[0047] Furthermore, the height of the drain port 17 is lower than the outlet of the spiral channel 7, so that the area below the drain port 17 and the area above the collection port 3 form a sedimentation chamber, which is used to separate the nickel crystals stripped from the stripped component from the sewage. The stripped nickel crystals, due to their density being much greater than that of the sewage, naturally settle at the bottom of the sedimentation chamber (above the lower end cover 102), and are discharged through the collection port 3 at the bottom when collection is required.

[0048] The further advantage of the above approach is that by setting the drain outlet 17 at a specific height below the outlet of the spiral channel 7, an electrolysis zone (within the spiral channel 7) and a sedimentation zone (sedimentation tank) are naturally divided within the treatment cylinder 1. After the nickel crystals are stripped off in the electrolysis zone above the spiral channel 7, they flow into the sedimentation chamber along with the wastewater for sedimentation, preventing interference with the continuous electrocrystallization process within the spiral channel 7. At the same time, the drain outlet 17 only allows the supernatant in the sedimentation chamber to overflow and be discharged, while the settled solid nickel crystals remain in the sedimentation chamber and are periodically collected by the staff by opening the collection port 3. This allows the wastewater that needs to be treated to be continuously inputted, processed, and discharged, solving the defect that traditional electrolytic recovery equipment must be shut down for batch cleaning, thereby improving the treatment efficiency.

[0049] Furthermore, multiple electrocrystallization modules are arranged along the direction of wastewater flow, and the current density in the electrocrystallization modules is set to decrease in a gradient to match the attenuation of ion concentration in the wastewater along the spiral flow channel 7. The positive terminal of the external power supply is electrically connected to the anode box 8, and the negative terminal of the power supply is electrically connected to the cathode box 9, so that each electrocrystallization module constitutes a potential-independent electrolysis circuit.

[0050] It should be noted that the electrocrystallization module in the initial stage is set with a high current density to quickly capture high concentrations of nickel ions. The electrocrystallization modules after the initial stage gradually reduce the current density to remove residual low concentrations of nickel ions, thereby saving energy and improving the overall recovery rate.

[0051] When this invention is used, the nickel-containing wastewater to be treated enters the spiral flow channel 7 through the inlet pipe 11, and the wastewater flow path is extended, providing sufficient time for electrolysis. Multiple electrocrystallization modules arranged along the water flow direction are activated, and the current density of each module decreases gradually according to the natural decay of the nickel ion concentration in the wastewater. The front-end module quickly captures high-concentration nickel ions with a higher current density, while the back-end module removes low-concentration ions with a lower current density, thus achieving efficient and energy-saving electrolytic recovery.

[0052] Nickel ions are reduced on the surface of the spindle-shaped titanium column 10, which serves as the cathode. During the reduction process, the roughened layer on the surface of the titanium column 10 provides abundant nucleation sites, accelerating the growth of metallic nickel crystals. After a suitable running time, the crystals grow to a predetermined thickness. At this time, the peeling push cylinder 13 in the anode box 8 is activated, pushing the peeling plate 14 with the rubber peeling sleeve 15 downward. The elastic deformation of the rubber peels off the fragile nickel crystal layer wrapped on the titanium column 10. The peeled blocky nickel crystals enter the sedimentation chamber below the spiral channel 7 with the water flow. Since the height of the drain port 17 is deliberately set below the outlet of the spiral channel 7, the supernatant in the sedimentation chamber can be continuously overflowed from the drain port 17. The denser solid nickel crystals will settle at the bottom of the sedimentation chamber.

[0053] Finally, the wastewater is continuously discharged through the drain outlet 17 to the existing purification equipment, and the metallic nickel can be periodically recovered through the bottom collection port 3, achieving uninterrupted operation without the need to add chemical agents, thereby improving the treatment efficiency and resource recovery efficiency of nickel-containing electroplating wastewater.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wastewater treatment device with metal recovery function, comprising a treatment cylinder (1), wherein the upper and lower ends of the treatment cylinder (1) are respectively provided with an upper end cover (101) and a lower end cover (102), characterized in that, The bottom of the upper end cover (101) is provided with a support column (2), the outer wall of the support column (2) is provided with an electrolytic flow field equalization component, the electrolytic flow field equalization component is provided with multiple electrocrystallization modules, and the bottom of the lower end cover (102) is provided with a collection port (3) for discharging the recovered nickel metal. The electrolytic flow field equalization component includes an upper spiral plate (4) and a lower spiral plate (5). The gap between the upper spiral plate (4) and the lower spiral plate (5) forms a spiral flow channel (7). The surfaces of the upper spiral plate (4) and the lower spiral plate (5) are provided with fan-shaped planes (6) parallel to the horizontal plane. The fan-shaped planes (6) are provided with mounting ports for installing electrocrystallization modules. The electrocrystallization module includes an anode box (8) mounted on an upper spiral plate (4) and a cathode box (9) mounted on a lower spiral plate (5). A stripping assembly is provided below the anode box (8), and a nickel crystal growth zone is provided above the cathode box (9). The nickel crystal growth zone is composed of multiple titanium pillars (10).

2. A wastewater treatment device with metal recovery function according to claim 1, characterized in that, The top of the upper cover (101) is provided with a cable and an inlet pipe (11), and the output end of the inlet pipe (11) is connected to the input end of the spiral flow channel (7).

3. A wastewater treatment device with metal recovery function according to claim 2, characterized in that, The support column (2) has a wiring through hole, so that the wires of the electrocrystallization module can be connected to the control system through the wiring through hole and the cable.

4. A wastewater treatment device with metal recovery function according to claim 1, characterized in that, The titanium column (10) is spindle-shaped, and the surface of the titanium column (10) is roughened by sandblasting to form a micro-layer. The titanium column (10) contains a steel core (12).

5. A wastewater treatment device with metal recovery function according to claim 4, characterized in that, The anode box (8) is provided with a stripping pusher cylinder (13). The piston rod of the stripping pusher cylinder (13) passes through the anode box (8) and is equipped with a stripping plate (14). The stripping plate (14) is provided with stripping holes that correspond one-to-one with the titanium pillars (10). The bottom of the anode box (8) is provided with an anode plate (801) to form an electrolytic electric field to guide the growth of nickel crystals.

6. A wastewater treatment device with metal recovery function according to claim 5, characterized in that, The peeling hole is provided with a rubber peeling sleeve (15), which uses the elastic expansion property of rubber to tightly adhere to the surface of the spindle-shaped titanium column (10) and peel off the nickel crystals on the surface of the titanium column (10) during the lifting and lowering action.

7. A wastewater treatment device with metal recovery function according to claim 6, characterized in that, The cathode box (9) is provided with a mounting plate (16) on its surface. The mounting plate (16) is provided with a threaded groove matching the titanium pillar (10) as a cathode contact. The threaded groove is connected to the steel core (12).

8. A wastewater treatment device with metal recovery function according to claim 1, characterized in that, The outer wall of the treatment cylinder (1) is equipped with a drain port (17). The height of the drain port (17) is lower than the outlet of the spiral flow channel (7), so that the area below the drain port (17) and the area above the collection port (3) form a sedimentation chamber for separating the nickel crystals from the stripped components from the wastewater.

9. A wastewater treatment device with metal recovery function according to claim 1, characterized in that, Multiple electrocrystallization modules are arranged along the direction of wastewater flow, and the current density in the electrocrystallization modules is set to decrease in a gradient to match the attenuation of ion concentration in wastewater along the spiral flow channel (7).

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