Low-acid-consumption multistage countercurrent leaching tank for zinc-rich paint slag recovery

Abstract

This utility model relates to the field of metal recycling technology, specifically a low-acid-consumption multi-stage countercurrent leaching tank for recovering zinc-rich paint sludge. It includes multiple tanks, each with a lid and a stirring motor mounted on top of the lid. A conical hopper is located at the bottom of each tank. The tank at the front conveys material to the next adjacent tank via a conveying mechanism. In the next tank, a separation mechanism separates the solid and liquid components, returning the liquid to the previous adjacent tank. This low-acid-consumption multi-stage countercurrent leaching tank for recovering zinc-rich paint sludge uses a conveying mechanism to transport incompletely dissolved paint sludge from the front tank to the next, achieving multi-stage treatment of the paint sludge. Simultaneously, the separation mechanism returns the liquid from the next tank to the previous tank, allowing the acid to circulate counter-currently in the multi-stage tanks. This ensures that the incompletely dissolved paint sludge encounters a new reaction environment in subsequent tanks, increasing the chances of dissolution and promoting more complete dissolution.

Description

Technical Field

[0001] This utility model relates to the field of metal recycling technology, specifically to a low-acid-consumption multi-stage countercurrent leaching tank for the recycling of zinc-rich paint slag. Background Technology

[0002] Zinc-rich paint sludge is a zinc-containing waste generated in the coatings industry. It has a high zinc content and is valuable for recycling. Recycling it can reduce solid waste pollution and achieve the reuse of zinc resources. The leaching tank is a key piece of equipment in the recycling process; through appropriate processes, zinc can be effectively extracted from the paint sludge, playing an important role in resource recycling and environmental protection.

[0003] Utility model patent CN222700372U discloses a novel aerated stirring leaching tank. This new tank includes a vertically arranged, hollow stirring shaft within the leaching tank. Several sets of symmetrically arranged air-filled pipes extend around the shaft to below the stirring blades. A one-way gas valve is installed at the bottom of each air-filled pipe. This novel aerated stirring leaching tank replaces the existing fixed-periphery air-filling system with a rotary air-filling device, rotating while air-filling. This results in better gas dispersion and sediment dispersion. Combined with the stirring device and a newly added rake, the air bubbles are cut to ensure more uniform dispersion and sufficient dissolved oxygen in all areas of the tank. Simultaneously, the sediment at the bottom, including the slurry and gold-loaded carbon, is dispersed and moved. Under the dual action of air filling and stirring, the slurry and gold-loaded carbon rise to participate in leaching, allowing the added activated carbon to be fully dispersed and adsorbed during the process without settling. This significantly improves the gold and silver leaching adsorption index, enhances the gold and silver leaching effect, and increases the gold and silver recovery rate.

[0004] In the process of recovering zinc metal from zinc-rich paint sludge, the degree of dissolution of the paint sludge powder is affected by factors such as acid concentration and reaction time. Incompletely dissolved paint sludge will settle at the bottom of the tank. Although it can be dispersed by rake, it is still limited to single-tank circulation processing and cannot perform step-by-step processing of undissolved paint sludge. As a result, some paint sludge cannot fully contact the fresh acid and may be incompletely dissolved. In view of this, we propose a low-acid-consumption multi-stage countercurrent leaching tank for the recovery of zinc-rich paint sludge. Utility Model Content

[0005] The purpose of this invention is to provide a low-acid-consumption multi-stage countercurrent leaching tank for the recovery of zinc-rich paint sludge, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery includes multiple horizontally arranged tanks. Each tank has a lid at its top, and a stirring motor is mounted on the top of the lid. A conical hopper is located at the bottom of each tank. The tank at the front of the tank conveys material to the next adjacent tank via a conveying mechanism. The next adjacent tank uses a separation mechanism to separate the conveyed material into solid and liquid phases, returning the liquid to the previous adjacent tank. The conveying mechanism includes a pump for conveying material between adjacent tanks. The separation mechanism includes a receiving box fixed to the inner wall of the tank and a filter belt circulating within the receiving box. The pump conveys material above the filter belt. A scraper is installed at the top end of the receiving box. The filter belt passes through the bottom of the scraper and adheres to it. The scraper scrapes any remaining solid material on the surface of the filter belt into the current tank.

[0007] Preferably, the top of the can lid is connected to a plurality of feed pipes, the bottom of the cone hopper is connected to a discharge pipe, and a discharge valve is installed at the end of the discharge pipe; In this setup, paint residue and acid can be added separately through the feed pipe, and the discharge valve can control the timing of the discharge of the processed material.

[0008] Preferably, the output shaft of the stirring motor is coaxially connected to a stirring rod, which extends into the interior of the tank. In this setting, the stirring rod rotates under the drive of the stirring motor, which allows the paint residue and acid solution to mix more evenly.

[0009] Preferably, a number of support legs are fixed to the bottom of the tank, and a number of connecting beams are fixed between the outer walls of two adjacent tanks; In this setup, the support legs provide support for the tanks, and the connecting beams enhance the overall stability of the multiple tanks.

[0010] Preferably, the delivery pump is mounted on a fixed base, which is fixed to the outer surface of the tank. The input end of the delivery pump is connected to an input pipe, and the output end of the delivery pump is connected to a discharge pipe. The first end of the input pipe is connected to the inside of the cone, and the end of the discharge pipe extends into the inside of the next tank. In this setup, the transfer pump draws material from the preceding tank through the input pipe and transports it to the next tank through the discharge pipe. The mounting bracket ensures that the transfer pump is installed securely.

[0011] Preferably, the receiving box has an open top box structure, the bottom of the receiving box is horizontal, and a return pipe is connected to the bottom of the side end of the receiving box. The end of the return pipe passes through the outer shell of the current tank and extends obliquely downward into the previous tank. In this setup, the receiving tank collects the separated liquid, and the return pipe sends the liquid back to the previous tank, thus achieving acid recycling.

[0012] Preferably, the filter belt is sleeved inside the receiving box, the top surface of the filter belt is flush with the top surface of the receiving box, the filter belt rotates cyclically at the opening of the receiving box, the filter belt has a mesh structure, and rotating columns are sleeved at both ends of the inner side of the filter belt. The ends of the rotating columns are rotatably connected to the side wall of the receiving box. One of the rotating columns is coaxially connected to a rotating motor. The rotating motor is located on the outside of the tank and is mounted on a base. The base is fixedly connected to the outer surface of the tank. In this setup, the rotating motor drives the filter belt to rotate via the rotating column, and the mesh filter belt achieves solid-liquid separation of the material. The rotating motor is fixed to the base.

[0013] Preferably, the filter belt is inclined with a higher first end and a lower second end inside the tank, and the end of the discharge pipe extends above the first end of the filter belt. In this setup, the inclined filter belt facilitates the movement of solid materials towards the end, and the discharge pipe can precisely deliver the material onto the filter belt.

[0014] Compared with the prior art, the beneficial effects of this utility model are: This low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery employs a design with multiple horizontally arranged tanks. A conveying mechanism transports incompletely dissolved paint sludge from one tank to the next, achieving multi-stage treatment of the paint sludge. Simultaneously, a separation mechanism returns the liquid after solid-liquid separation from the next tank to the previous tank, allowing the acid to circulate counter-currently within the multi-stage tanks. This structure allows incompletely dissolved paint sludge to come into contact with a new reaction environment in subsequent tanks, increasing the chances of dissolution. The countercurrent reflux of the acid improves acid utilization and reduces acid consumption, thereby promoting more complete dissolution of the paint sludge. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the tank in this utility model; Figure 3 This is a schematic diagram of the conveying mechanism in this utility model; Figure 4 This is a schematic diagram of the separation mechanism in this utility model; Figure 5 This is a schematic diagram of the structure of the receiving box in this utility model; Figure 6 This is a schematic diagram of the filter belt structure in this utility model; The meanings of the labels in the diagram are as follows: 100. Tank; 110. Tank lid; 111. Feed pipe; 120. Agitator motor; 121. Agitator rod; 130. Conical hopper; 140. Discharge valve; 150. Support leg; 160. Connecting beam; 200. Conveying mechanism; 210. Conveying pump; 211. Mounting base; 220. Input pipe; 230. Discharge pipe; 300. Separation mechanism; 310. Receiver box; 311. Return pipe; 312. Scraper; 320. Filter belt; 321. Rotating column; 322. Rotating motor; 3221. Base. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Please see Figures 1-6The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery includes multiple horizontally arranged tanks 100. Each tank 100 is made of acid-resistant stainless steel to resist corrosion from the acid solution during leaching. A tank cover 110, also made of acid-resistant stainless steel, is installed at the top of each tank 100. A stirring motor 120 is installed at the top of each tank cover 110. A conical hopper 130 is integrally formed with the tank 100 and is made of acid-resistant stainless steel. The tank 100 is made of stainless steel and its conical structure facilitates material accumulation at the bottom for convenient subsequent conveying. The top of the tank lid 110 is connected to several feed pipes 111, which are made of polytetrafluoroethylene (PTFE) and have good acid resistance, allowing for the addition of paint residue and acid. The bottom of the conical hopper 130 is connected to a discharge pipe, also made of PTFE, with a discharge valve 140 at its end. The discharge valve 140 is made of an acid-resistant alloy, facilitating control of the final material discharge. The output shaft of the stirring motor 120 is coaxially connected to a stirring rod 121, made of titanium alloy, which has excellent acid resistance. The stirring rod 121 extends into the tank 100 to stir the material inside, ensuring thorough contact between the paint residue and acid, thus improving dissolution efficiency. The bottom of the tank 100 is fixed with several support legs 150. The support legs 150 are made of ordinary carbon steel and have anti-corrosion treatment on the surface. They are used to support the entire tank 100. Several connecting beams 160 are fixed between the outer walls of two adjacent tanks 100. The connecting beams 160 are made of ordinary carbon steel and have anti-corrosion treatment on the surface. They enhance the connection stability between multiple tanks 100.

[0018] like Figure 1 and Figure 3 As shown, in this utility model, the tank 100 located at the front side transports materials to the next adjacent tank 100 via a conveying mechanism 200. The conveying mechanism 200 includes a conveying pump 210, the part of the conveying pump 210 in contact with the material is made of acid-resistant stainless steel. The conveying pump 210 is used for material conveying between two adjacent tanks 100, realizing step-by-step material processing. The conveying pump 210 is mounted on a fixed base 211, which is made of ordinary carbon steel and is fixed to the outer surface of the tank 100. The pump 210 provides stable support. The input end of the pump 210 is connected to an input pipe 220, which is made of polytetrafluoroethylene (PTFE). The output end of the pump 210 is connected to a discharge pipe 230, which is also made of PTFE. The first end of the input pipe 220 is connected to the inside of the cone 130, which facilitates the suction of material gathered in the cone 130. The end of the discharge pipe 230 extends into the inside of the next tank 100, which can accurately transport the material to the next tank 100.

[0019] like Figure 1 and Figure 4 As shown, specifically, the next tank 100 uses a separation mechanism 300 to separate the solid and liquid components of the conveyed material, and then returns the liquid to the previous adjacent tank 100. The separation mechanism 300 includes a receiving box 310 fixed to the inner wall of the tank 100 and a filter belt 320 circulating within the receiving box 310. The receiving box 310 is made of acid-resistant stainless steel and is used to receive the liquid after solid-liquid separation. The filter belt 320 is made of acid-resistant polyester fiber and has good filtration properties. With good acid resistance, the conveying pump 210 conveys the material to the top of the filter belt 320. A scraper 312 is installed at the top end of the receiving box 310. The scraper 312 is made of polytetrafluoroethylene. The filter belt 320 passes through the bottom of the scraper 312 and is in contact with the filter belt 320. The scraper 312 is used to scrape the solid material remaining on the surface of the filter belt 320 into the current tank 100, so as to avoid the solid material from being left behind as the filter belt 320 circulates.

[0020] like Figure 4 and Figure 5 As shown, the receiving box 310 has an open-top box structure to facilitate the collection of liquid dripping from the filter belt 320. The bottom of the receiving box 310 is horizontal. A return pipe 311 is connected to the bottom of the side end of the receiving box 310. The return pipe 311 is made of polytetrafluoroethylene. The end of the return pipe 311 penetrates the outer shell of the current tank 100 and extends obliquely downward into the previous tank 100. This allows the liquid collected in the receiving box 310 to flow back to the previous tank 100, improving the utilization rate of the acid.

[0021] like Figure 4 and Figure 6As shown, the filter belt 320 is fitted inside the receiving box 310, with its top surface flush with the top surface of the receiving box 310. The filter belt 320 rotates continuously at the opening of the receiving box 310, facilitating continuous filtration of the incoming material. The filter belt 320 has a mesh structure, allowing liquid to pass through and drip into the receiving box 310. Rotating columns 321 are fitted at both ends of the inner side of the filter belt 320. The rotating columns 321 are made of acid-resistant stainless steel. The end of the filter belt 320 is rotatably connected to the side wall of the receiving box 310, providing support for the rotation of the filter belt 320. One of the rotating columns 321 is coaxially connected to a rotating motor 322, which provides power for the rotation of the filter belt 320. The rotating motor 322 is located on the outside of the tank 100 and is mounted on a base 3221. The base 3221 is made of ordinary carbon steel and is fixedly connected to the outer surface of the tank 100 to provide stable support for the rotating motor 322.

[0022] like Figure 4 and Figure 6 As shown, it is worth noting that the filter belt 320 is inclined with a high head and a low tail inside the tank 100, which facilitates the movement of solid materials to the tail under the action of gravity, making it easier for the scraper 312 to scrape them off. The end of the discharge pipe 230 extends above the head of the filter belt 320, so that the conveyed material can accurately fall onto the filter belt 320 for filtration.

[0023] It is worth noting that the stirring motor 120, the delivery pump 210, and the rotating motor 322 involved in this utility model are all existing conventional technologies, and will not be described in detail in this utility model.

[0024] In this embodiment, the low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery operates as follows: First, zinc-rich paint sludge and acid are added to the front tank 100 through the feed pipe 111. The stirring motor 120 drives the stirring rod 121 to rotate, mixing the materials. Then, the deposited paint sludge material in the front tank 100 gathers in the cone hopper 130, is drawn in through the input pipe 220 by the conveying pump 210, and is then conveyed to the filter belt 320 of the next tank 100 through the discharge pipe 230. Next, the rotating motor 322 drives the rotating column 321 to rotate, causing the filter belt 320 to rotate cyclically. The material undergoes solid-liquid separation on the filter belt 320. The liquid drips into the receiving tank 310 and flows back to the previous tank 100 through the return pipe 311. The solid material is scraped into the current tank 100 by the scraper 312 and continues to be stirred and processed in the current tank 100. Finally, after processing in the multi-stage tanks 100, the zinc-rich paint sludge is fully acidified.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery, comprising multiple horizontally arranged tanks (100), characterized in that: The top of the tank (100) is fitted with a tank cover (110), and a stirring motor (120) is fitted on the top of the tank cover (110). A conical hopper (130) is provided at the bottom of the tank (100). The tank (100) at the front is conveyed to the next adjacent tank (100) via a conveying mechanism (200). The next adjacent tank (100) separates the conveyed material into solid and liquid phases via a separation mechanism (300), returning the liquid to the previous adjacent tank (100). The conveying mechanism (200) includes a conveying pump (210), which is used for connecting two adjacent tanks. Material transfer between tanks (100), the separation mechanism (300) includes a receiving box (310) fixed to the inner wall of the tank (100) and a filter belt (320) circulating in the receiving box (310). The transfer pump (210) transports the material above the filter belt (320). A scraper (312) is installed at the top end of the receiving box (310). The filter belt (320) passes through the bottom of the scraper (312) and adheres to the filter belt (320). The scraper (312) is used to scrape the solid material remaining on the surface of the filter belt (320) into the current tank (100).

2. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint slag recovery according to claim 1, characterized in that: The top of the can lid (110) is connected to several feed pipes (111), the bottom of the cone hopper (130) is connected to a discharge pipe, and a discharge valve (140) is installed at the end of the discharge pipe.

3. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery according to claim 1, characterized in that: The output shaft of the stirring motor (120) is coaxially connected to a stirring rod (121), which extends into the interior of the tank (100).

4. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint slag recovery according to claim 1, characterized in that: The bottom of the tank (100) is fixed with several support legs (150), and several connecting beams (160) are fixed between the outer walls of two adjacent tanks (100).

5. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint slag recovery according to claim 1, characterized in that: The delivery pump (210) is mounted on a fixed base (211), which is fixed to the outer surface of the tank (100). The input end of the delivery pump (210) is connected to an input pipe (220), and the output end of the delivery pump (210) is connected to a discharge pipe (230). The first end of the input pipe (220) is connected to the inside of the cone (130), and the end of the discharge pipe (230) extends into the inside of the next tank (100).

6. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint slag recovery according to claim 1, characterized in that: The receiving box (310) has an open top box structure. The bottom of the receiving box (310) is horizontal. A return pipe (311) is connected to the bottom of the side end face of the receiving box (310). The end of the return pipe (311) penetrates the outer shell of the current tank (100) and extends obliquely downward into the previous tank (100).

7. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint sludge recovery according to claim 1, characterized in that: The filter belt (320) is fitted inside the receiving box (310). The top surface of the filter belt (320) is flush with the top surface of the receiving box (310). The filter belt (320) rotates cyclically at the opening of the receiving box (310). The filter belt (320) has a mesh structure. Rotating columns (321) are fitted at both ends of the inner side of the filter belt (320). The ends of the rotating columns (321) are rotatably connected to the side wall of the receiving box (310). One of the rotating columns (321) is coaxially connected to a rotating motor (322). The rotating motor (322) is located on the outside of the tank (100). The rotating motor (322) is mounted on a base (3221). The base (3221) is fixedly connected to the outer surface of the tank (100).

8. The low-acid-consumption multi-stage countercurrent leaching tank for zinc-rich paint slag recovery according to claim 5, characterized in that: The filter belt (320) is inclined inside the tank (100) with the first end higher than the last end, and the end of the discharge pipe (230) extends above the first end of the filter belt (320).

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