A method for treating hot-dip galvanizing waste

Abstract

The present application belongs to the technical field of industrial waste resource processing, and particularly relates to a hot galvanizing waste processing method. The hot galvanizing waste processing method comprises the following steps: 1) zinc liquid preparation; 2) hot galvanizing waste arrangement; 3) zinc removal treatment; 4) purification; and 5) plating liquid preparation. The processing method can realize clean resource utilization of the hot galvanizing waste, and does not produce other waste, thereby reducing the purchasing cost of the hot galvanizing enterprise. The hot galvanizing waste processing method has low production cost, small investment, environmental friendliness, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial waste resource processing, and particularly relates to a treatment method of hot galvanizing waste. BACKGROUND

[0002] The damage of the surrounding medium to the metal material is called metal corrosion. Steel is the most widely used metal material, and is prone to metal corrosion in the air environment. Zinc, as an important non-ferrous metal, has excellent corrosion resistance and wear resistance, unique electrochemical properties, suitable mechanical properties, and is widely used in zinc plating corrosion prevention, battery manufacturing, alloy manufacturing and other fields. Hot galvanizing is a process technology that puts steel, stainless steel, cast iron and other metals into a molten zinc bath to form a zinc and zinc-iron alloy coating on the surface. Not only can it isolate steel from air, seawater, soil and other working environments, but also the standard electrode potential of zinc is negative than that of iron. In various corrosive media, the zinc coating also has the effect of sacrificial anode protection of the steel base, which is the best solution to steel corrosion at present.

[0003] During the hot galvanizing process of steel in a steel plant, due to process anomalies and equipment failures, etc., a certain proportion of the steel surface is not plated, and the quality of the plated zinc layer does not meet the standards, etc., resulting in about 1% of the yield of waste. Under normal circumstances, these hot galvanizing waste is hoisted into an acid pickling tank for pickling to remove the surface zinc layer. During the waste pickling process, a large amount of acid is consumed, and the dissolution of the zinc layer into the acid will result in zinc in the pickling solution, increasing the difficulty of recycling the pickling solution, and creating obstacles for further resource utilization, resulting in great resource waste.

[0004] The patent for invention with publication number CN104195559A discloses a method for zinc layer stripping of steel pipe surface. The zinc layer stripping steel pipe to be treated is placed in a zinc stripping solution, and reacts for 3-6 hours at a temperature of 60-90℃. The treated steel pipe is rinsed with cold water to obtain the zinc layer stripping of steel pipe surface. The zinc stripping solution is a mixed aqueous solution of potassium hydroxide and potassium iodide. The method for recovering zinc from the zinc layer stripping of steel pipe surface is as follows: the zinc stripping solution is placed in an electrolytic cell, a stainless steel plate is used as the anode, and a titanium alloy plate TC4 is used as the cathode. The electrolytic reaction is carried out for 2-4 hours, and then the zinc powder on the surface of the cathode is collected, cleaned and dried. The above method is simple to operate, but the potassium iodide in the zinc stripping solution will react with iron, which still causes certain difficulties in recycling the zinc stripping solution. Moreover, the zinc stripping solution recovery process is complex and has high recovery cost, which is not suitable for industrial production. In addition, the reaction needs to be carried out at a temperature of 60-90℃ for 3-6 hours. The activity of hydrochloric acid will increase significantly at high temperature, and the reaction speed with iron will be intensified. A large amount of iron will dissolve into the acid solution, resulting in high acid consumption and thinning of the steel pipe, which makes it difficult to reuse the steel pipe. In addition, the stainless steel plate is used as the anode in the electrolysis process, and the stainless steel will be quickly dissolved, which is also difficult to operate stably in industry.

[0005] Chinese patent CN115449795A discloses a method for treating galvanized waste using the zinc chloride-ammonia method. This method involves batch-adding the galvanized waste to a leaching tank containing hydrochloric acid and ammonium chloride in a zinc-removing aqueous solution. The addition of hydrochloric acid and ammonium chloride to the leaching tank is automatically controlled, maintaining the hydrochloric acid concentration at 4–6 g / L and the ammonium chloride concentration at 33–37 g / L. Heating is also automatically controlled, maintaining the temperature of the zinc-removing aqueous solution at 48–52°C. This method also utilizes high-temperature hydrochloric acid, significantly increasing its reactivity and accelerating the reaction between the hydrochloric acid and the steel substrate. This results in high acid consumption and thinner steel pipes, making reuse of the pipes difficult. Furthermore, the solution remains acidic after zinc removal, requiring zinc powder to replace and purify iron ions, leading to high zinc powder consumption and difficulty in thoroughly purifying the iron ions. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the present invention aims to provide a method for treating hot-dip galvanizing waste. This method, through zinc stripping solution preparation, hot-dip galvanizing waste sorting, zinc removal treatment, purification, and flux preparation, achieves full resource utilization of hot-dip galvanizing waste, reducing procurement costs for hot-dip galvanizing enterprises.

[0007] The technical solution of the present invention to solve the above problems is as follows:

[0008] A method for treating hot-dip galvanizing waste includes the following steps:

[0009] 1) Preparation of zinc stripping solution: Inject 1-5 wt% hydrochloric acid solution into the pickling tank, then add pickling aid, mix evenly to obtain zinc stripping solution;

[0010] 2) Hot-dip galvanizing waste sorting: The hot-dip galvanizing waste is sorted and sorted according to the pipe specifications, and after cleaning, the hot-dip galvanizing waste to be processed is obtained.

[0011] 3) Dezincification treatment: The hot-dip galvanized waste to be treated is put into the zinc stripping solution in batches for dezincification treatment. Each batch is hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out and washed and coated to obtain qualified galvanized material, realizing the resource utilization of hot-dip galvanized waste.

[0012] During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and an acid pump is automatically injected into the zinc stripping solution with 33-36 wt% industrial hydrochloric acid to maintain the pH of the zinc stripping solution at 1-2.5. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350 g / L, the addition of hot-dip galvanized waste to be treated to the zinc stripping solution is stopped. The zinc stripping solution obtained at this time is the dezincified zinc stripping solution.

[0013] In the above technical solution, when the pH of the zinc stripping solution is between 1 and 2.5, the zinc layer on the surface of hot-dip galvanized waste dissolves relatively quickly, but the corrosion rate of the zinc stripping solution on the steel is relatively slow. The concentration of zinc chloride in the zinc stripping solution is greater than 350 g / L, which is significantly higher than the zinc concentration of greater than or equal to 200 g / L in the zinc stripping aqueous solution disclosed in CN115449795A. As is well known, the higher the concentration of zinc chloride in the zinc stripping solution, the more beneficial it is for the zinc chloride solution to be recycled within the galvanizing plant. However, too high a concentration will lead to crystal precipitation. The technical solution of this invention can achieve a zinc chloride concentration as high as 350 g / L, which is beneficial for reducing production costs. Secondly, in the zinc stripping process of this invention, the hydrochloric acid is at room temperature, which can reduce its reaction rate with the steel substrate, thereby reducing the iron ion concentration in the zinc stripping solution and the difficulty of subsequent iron removal.

[0014] 4) Purification: Add hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.5-5.0 with ammonia to obtain the purified zinc stripping solution.

[0015] In the above technical solution, during the ammonia water purification process, the ammonia water is eventually converted into ammonium chloride. Ammonium chloride is one of the raw materials used by hot-dip galvanizing enterprises for fluxing. Therefore, the purified product does not contain impurities, which is conducive to the recycling of the purified zinc stripping solution.

[0016] 5) Preparation of flux solution: The zinc chloride and ammonium chloride in the purified zinc stripping solution are quantitatively detected. Then, according to the fluxing process parameters of hot-dip galvanizing, a flux solution with a zinc chloride concentration of 70-270 g / L and an ammonium chloride concentration of 100-270 g / L is prepared and transported to the fluxing tank for use as a flux solution, so as to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

[0017] As a preferred embodiment of the above technical solution, in step 1), the 1-5 wt% hydrochloric acid solution is obtained by diluting 33-36 wt% industrial hydrochloric acid with water.

[0018] As a preferred embodiment of the above technical solution, in step 1), the pickling aid is one or both of acid mist inhibitors and defoamers.

[0019] As a preferred embodiment of the above technical solution, the pickling aid is an acid mist inhibitor and a defoamer, and the two are added separately.

[0020] As a preferred embodiment of the above technical solution, the amount of acid mist inhibitor added is 0.03-1.5 wt%, and the amount of defoamer added is 0.001-0.01 wt%.

[0021] In existing technologies, zinc stripping solutions typically use only hydrochloric acid solutions. While removing the surface zinc layer, this damages the steel substrate, reducing its reusability. To avoid this, the hydrochloric acid concentration is usually reduced, but this also decreases the zinc layer's reaction rate, leading to longer processing times and hindering industrial production. Therefore, this invention incorporates acid mist inhibitors and defoamers as pickling aids in the zinc stripping solution without reducing the hydrochloric acid concentration. This is because acid mist inhibitors reduce the activity of hydrochloric acid, passivating the steel and thus slowing its dissolution rate in the hydrochloric acid (corrosion inhibition rate can reach over 99.5%). However, acid mist inhibitors contain organic matter and release hydrogen gas during the dissolution of zinc on the scrap steel surface, generating a large amount of foam. Therefore, they need to be used in conjunction with defoamers to prevent liquid from escaping from the pickling tank.

[0022] As a preferred embodiment of the above technical solution, in step 2), the hot-dip galvanizing waste is galvanized material that is defective in quality due to incomplete galvanizing, substandard zinc layer, etc., and needs to be degalvanized and regalvanized.

[0023] As a preferred embodiment of the above technical solution, in step 4), the concentration of hydrogen peroxide is 1-5%.

[0024] As a preferred embodiment of the above technical solution, in step 4), the concentration of iron ions in the zinc stripping solution after purification is less than 3 g / L.

[0025] In the above technical solution, since a small amount of iron inevitably dissolves in the zinc stripping solution after zinc removal (metallic iron and zinc react with hydrochloric acid solution to form zinc chloride and ferrous chloride solution), 1-5% hydrogen peroxide is first added to the solution to completely oxidize the ferrous ions in the solution to ferric ions. Then, ammonia water is used to adjust the pH to 4.5-5.0 to completely precipitate the iron ions in the solution, resulting in a purified zinc stripping solution with an iron ion concentration of less than 3 g / L.

[0026] In summary, the present invention has the following beneficial effects:

[0027] 1. This invention uses waste generated during the hot-dip galvanizing process as raw material, dissolves the zinc on its surface to obtain zinc chloride solution, and realizes the resource recovery of zinc on the surface of hot-dip galvanizing waste.

[0028] 2. After the zinc layer dissolves in the zinc stripping solution, it is converted into zinc chloride. Zinc chloride is one of the essential raw materials for hot-dip galvanizing enterprises. After subsequent purification, a high-concentration zinc chloride and ammonium chloride solution is obtained, which can be further formulated into a fluxing solution to reduce the procurement cost of hot-dip galvanizing enterprises.

[0029] 3. Because acid mist inhibitors are added to the zinc stripping solution, the dissolution rate of iron by hydrochloric acid can be inhibited. Therefore, the iron content in the solution after zinc stripping and the difficulty of iron removal can be greatly reduced, and the dimensional and mechanical strength of the galvanized material after zinc stripping can be guaranteed without affecting the resource utilization of hot-dip galvanizing waste.

[0030] 4. The treatment method of this invention not only achieves the clean utilization of hot-dip galvanizing waste but also generates no other waste. Furthermore, the addition of an acid mist inhibitor suppresses the volatilization of hydrochloric acid mist, resulting in a better working environment. This treatment method has low production costs, requires minimal investment, is environmentally friendly, and is suitable for industrial production. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments. However, the specific details of the embodiments are only for illustrating the present invention and do not represent all technical methods under the concept of the present invention. Therefore, they should not be construed as limiting the overall technical solution of the present invention.

[0032] Example 1

[0033] A method for treating hot-dip galvanizing waste includes the following steps:

[0034] 1) Prepare a 1wt% dilute hydrochloric acid solution using 33-36wt% industrial hydrochloric acid, inject it into a dedicated pickling tank, and then add 0.03wt% acid mist inhibitor and 0.001wt% defoamer in sequence, mix evenly, and obtain zinc stripping solution;

[0035] 2) The hot-dip galvanized waste is sorted and cleaned according to the pipe specifications to obtain the hot-dip galvanized waste to be processed.

[0036] 3) The hot-dip galvanized waste to be treated is put into the zinc stripping solution in batches for dezincification treatment. Each batch is hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified zinc-plated material, realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, the pH of the zinc stripping solution is monitored by a pH meter, and the acid pump is controlled to automatically inject 33-36wt% hydrochloric acid into the zinc stripping solution to maintain the pH of the zinc stripping solution at 1. After multiple batches of hot-dip galvanized waste are dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350g / L, the addition of hot-dip galvanized waste to be treated to the zinc stripping solution is stopped, and the dezincified zinc stripping solution is obtained.

[0037] 4) Add 1% hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.5 with ammonia to obtain the purified zinc stripping solution.

[0038] 5) Quantitatively detect the zinc chloride and ammonium chloride in the purified zinc stripping solution. Then, according to the fluxing process parameters of hot-dip galvanizing, prepare a fluxing solution with a zinc chloride concentration of 70 g / L and an ammonium chloride concentration of 100 g / L, and transport it to the fluxing tank for use as a fluxing solution to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

[0039] Example 2

[0040] A method for treating hot-dip galvanizing waste includes the following steps:

[0041] 1) Prepare a 5wt% dilute hydrochloric acid solution using 33-36wt% industrial hydrochloric acid, inject it into a dedicated pickling tank, and then add 1.5wt% acid mist inhibitor and 0.01wt% defoamer in sequence, mix evenly, and obtain the zinc stripping solution.

[0042] 2) The hot-dip galvanized waste is sorted and cleaned according to the pipe specifications to obtain the hot-dip galvanized waste to be processed.

[0043] 3) The hot-dip galvanized waste to be treated is added to the zinc stripping solution in batches for dezincification treatment. Each batch consists of hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified galvanized material, thus realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and the acid pump is controlled to automatically inject 33-36wt% hydrochloric acid into the zinc stripping solution to maintain the pH of the zinc stripping solution at 2.5. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350g / L, the addition of the hot-dip galvanized waste to be treated to the zinc stripping solution is stopped, and the dezincified zinc stripping solution is obtained.

[0044] 4) Add 5% hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 5.0 with ammonia to obtain the purified zinc stripping solution.

[0045] 5) Quantitatively detect the zinc chloride and ammonium chloride in the purified zinc stripping solution. Then, according to the fluxing process parameters of hot-dip galvanizing, prepare a fluxing solution with a zinc chloride concentration of 270 g / L and an ammonium chloride concentration of 270 g / L, and transport it to the fluxing tank for use as a fluxing solution to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

[0046] Example 3

[0047] A method for treating hot-dip galvanizing waste includes the following steps:

[0048] 1) Prepare a 2wt% dilute hydrochloric acid solution using 33-36wt% industrial hydrochloric acid, inject it into a dedicated pickling tank, and then add 0.04wt% acid mist inhibitor and 0.003wt% defoamer in sequence, mix evenly to obtain zinc stripping solution;

[0049] 2) The hot-dip galvanized waste is sorted and cleaned according to the pipe specifications to obtain the hot-dip galvanized waste to be processed.

[0050] 3) The hot-dip galvanized waste to be treated is added to the zinc stripping solution in batches for dezincification treatment. Each batch consists of hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified galvanized material, thus realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and the acid pump is controlled to automatically inject 33-36wt% hydrochloric acid into the zinc stripping solution to maintain the pH of the zinc stripping solution at 1.5. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350g / L, the addition of the hot-dip galvanized waste to be treated to the zinc stripping solution is stopped, and the dezincified zinc stripping solution is obtained.

[0051] 4) Add 2v% hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.6 with ammonia to obtain the purified zinc stripping solution.

[0052] 5) Quantitatively detect the zinc chloride and ammonium chloride in the purified zinc stripping solution. Then, according to the fluxing process parameters of hot-dip galvanizing, prepare a fluxing solution with a zinc chloride concentration of 100g / L and an ammonium chloride concentration of 150g / L, and transport it to the fluxing tank for use as a fluxing solution to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

[0053] Example 4

[0054] A method for treating hot-dip galvanizing waste includes the following steps:

[0055] 1) Prepare a 4wt% dilute hydrochloric acid solution using 33-36wt% industrial hydrochloric acid, pour it into a dedicated pickling tank, and then add 0.08wt% acid mist inhibitor and 0.005wt% defoamer in sequence, mix evenly, and obtain the zinc stripping solution.

[0056] 2) The hot-dip galvanized waste is sorted and cleaned according to the pipe specifications to obtain the hot-dip galvanized waste to be processed.

[0057] 3) The hot-dip galvanized waste to be treated is added to the zinc stripping solution in batches for dezincification treatment. Each batch consists of hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified galvanized material, thus realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and the acid pump is controlled to automatically inject 33-36wt% hydrochloric acid into the zinc stripping solution to maintain the pH of the zinc stripping solution at 1.6. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350g / L, the addition of the hot-dip galvanized waste to be treated to the zinc stripping solution is stopped, and the dezincified zinc stripping solution is obtained.

[0058] 4) Add 3% hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.8 with ammonia to obtain the purified zinc stripping solution.

[0059] 5) Quantitatively detect the zinc chloride and ammonium chloride in the purified zinc stripping solution. Then, according to the fluxing process parameters of hot-dip galvanizing, prepare a fluxing solution with a zinc chloride concentration of 80 g / L and an ammonium chloride concentration of 160 g / L, and transport it to the fluxing tank for use as a fluxing solution to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

[0060] Example 5

[0061] A method for treating hot-dip galvanizing waste includes the following steps:

[0062] 1) Prepare a 3.5 wt% dilute hydrochloric acid solution using 33-36 wt% industrial hydrochloric acid, pour it into a dedicated pickling tank, and then add 1.0 wt% acid mist inhibitor and 0.008 wt% defoamer in sequence, mix evenly, and obtain zinc stripping solution;

[0063] 2) The hot-dip galvanized waste is sorted and cleaned according to the pipe specifications to obtain the hot-dip galvanized waste to be processed.

[0064] 3) The hot-dip galvanized waste to be treated is added to the zinc stripping solution in batches for dezincification treatment. Each batch consists of hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified galvanized material, thus realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and the acid pump is controlled to automatically inject 33-36wt% hydrochloric acid into the zinc stripping solution to maintain the pH of the zinc stripping solution at 2.2. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350g / L, the addition of the hot-dip galvanized waste to be treated to the zinc stripping solution is stopped, and the dezincified zinc stripping solution is obtained.

[0065] 4) Add 4% hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.7 with ammonia to obtain the purified zinc stripping solution.

[0066] 5) Quantitatively detect the zinc chloride and ammonium chloride in the purified zinc stripping solution. Then, according to the fluxing process parameters of hot-dip galvanizing, prepare a fluxing solution with a zinc chloride concentration of 120 g / L and an ammonium chloride concentration of 180 g / L, and transport it to the fluxing tank for use as a fluxing solution to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

Claims

1. A method for treating hot-dip galvanizing waste, characterized in that, Includes the following steps: 1) Preparation of zinc stripping solution: Inject 1~5wt% hydrochloric acid solution into pickling tank, then add pickling aid, mix evenly to obtain zinc stripping solution, the temperature of the zinc stripping solution is room temperature; 2) Hot-dip galvanizing waste sorting: The hot-dip galvanizing waste is sorted and sorted according to the pipe specifications, and after being cleaned, the hot-dip galvanizing waste to be processed is obtained. 3) Dezincification treatment: The hot-dip galvanized waste to be treated is put into the zinc stripping solution in batches for dezincification treatment. Each batch is hot-dip galvanized waste of the same specification. After the zinc layer on the surface of the hot-dip galvanized waste is completely removed, it is taken out, washed and coated with flux to obtain qualified galvanized material, realizing the resource utilization of hot-dip galvanized waste. During the dezincification process, a pH meter is used to monitor the pH of the zinc stripping solution, and an acid pump is automatically injected into the zinc stripping solution with 33-36 wt% industrial hydrochloric acid to maintain the pH of the zinc stripping solution at 1-2.

5. After multiple batches of hot-dip galvanized waste have been dezincified, when the concentration of zinc chloride in the zinc stripping solution is greater than 350 g / L, the addition of hot-dip galvanized waste to be treated to the zinc stripping solution is stopped. The zinc stripping solution obtained at this time is the dezincified zinc stripping solution. 4) Purification: Add hydrogen peroxide to the zinc stripping solution after zinc removal and mix well. Then adjust the pH of the solution to 4.5~5.0 with ammonia to obtain the purified zinc stripping solution. 5) Preparation of flux solution: The zinc chloride and ammonium chloride in the purified zinc stripping solution are quantitatively detected. Then, according to the fluxing process parameters of hot-dip galvanizing, the flux solution is prepared and transported to the fluxing tank for use as flux solution, so as to realize the recycling of zinc on the surface of hot-dip galvanizing waste.

2. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, In step 1), the 1-5 wt% hydrochloric acid solution is obtained by diluting 33-36 wt% industrial hydrochloric acid with water.

3. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, In step 1), the pickling aid is one or both of acid mist inhibitors and defoamers.

4. The method for treating hot-dip galvanizing waste according to claim 3, characterized in that, The pickling aids are acid mist inhibitors and defoamers, and the two are added separately.

5. The method for treating hot-dip galvanizing waste according to claim 4, characterized in that, The amount of acid mist inhibitor added is 0.03~1.5wt%, and the amount of defoamer added is 0.001~0.01wt%.

6. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, In step 2), the hot-dip galvanizing waste refers to galvanized materials that are missing during the hot-dip galvanizing process, have substandard zinc layers, and require stripping and re-galvanizing.

7. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, In step 4), the concentration of hydrogen peroxide is 1~5v.

8. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, Step 4) The concentration of iron ions in the purified zinc stripping solution is less than 3 g / L.

9. The method for treating hot-dip galvanizing waste according to claim 1, characterized in that, In step 5), the zinc chloride concentration in the flux is 70~270g / L and the ammonium chloride concentration is 100~270g / L.