Regeneration cycle treatment method for zinc-containing waste acid in hot galvanizing process

Abstract

The invention relates to the technical field of waste cyclic regeneration, and discloses a regeneration cyclic treatment method of zinc-containing waste acid in a hot galvanizing process, which comprises the following steps: step 1, zinc stripping: adding a zinc stripping additive into the zinc-containing waste acid, the zinc stripping additive being a mixture of a wetting agent and a corrosion inhibitor; step 2, iron removal: adding an iron removal agent into the zinc-containing waste acid after zinc removal, and stirring, wherein the content of iron ions in the waste liquid after the iron removal process is lower than 1g / L; step 3, electrolysis: using insoluble metal materials such as a titanium plate, a lead plate, a graphite plate and a lead alloy plate as an anode plate, and using a zinc plate, an aluminum plate or a stainless steel plate as a cathode plate; and when the concentration of zinc ions in the waste liquid is lower than 60g / L, electrolysis is stopped. And removing metal ions from the electrolyzed waste liquid, recovering the zinc removal capability, and returning to the step 1 to continuously remove the zinc. According to the invention, closed-loop circulation is realized, no wastewater is discharged, the requirement of wastewater treatment is eliminated, and the environmental protection cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of waste recycling, and in particular to a method for recycling and treating zinc-containing waste acid in a hot-dip galvanizing process. Background Art

[0002] As a vital component of China's infrastructure, the hot-dip galvanizing industry plays an irreplaceable role in promoting national economic development and social progress. However, the hot-dip galvanizing process inevitably generates a significant amount of waste zinc stripping liquid. This waste primarily originates from various hangers and from the strong acid stripping of the zinc coating on substandard products. In China, this waste zinc stripping liquid, containing high concentrations of zinc ions and other harmful substances, is classified as hazardous waste. If discharged directly into the environment without proper treatment, it will cause severe pollution to ecosystems such as soil and water sources, and long-term accumulation will pose a significant threat to the ecological environment.

[0003] Zinc stripping wastewater has complex and hazardous components, requiring extremely high technical requirements and high costs to treat, significantly increasing operating costs for manufacturers. Currently, the industry's commonly used methods for treating zinc-containing waste acid include vacuum distillation and extractive electrolysis. Vacuum distillation suffers from poor treatment results, resulting in high impurity levels in the treated product, making it difficult to achieve optimal purification. While extractive electrolysis can achieve a certain level of treatment, it requires large amounts of expensive extractant and centrifugal separation equipment. Furthermore, the extractant is lost during the treatment process, and the wastewater after extraction and electrolysis cannot be recycled, resulting in incomplete treatment and insufficient economic and environmental performance. To address these issues, existing technologies attempt to oxidize ferrous ions, then increase the pH, and finally achieve separation through precipitation of ferric hydroxide. However, because ferric hydroxide forms a colloidal state during its formation, existing industrial equipment struggles to meet the separation requirements, making this method difficult to implement in practical production. Summary of the Invention

[0004] The present invention aims to provide a regeneration and recycling treatment method for zinc-containing waste acid in a hot-dip galvanizing process, so as to solve the problems of unsatisfactory treatment effect and difficult separation of zinc-containing waste acid in the prior art.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical scheme: a regeneration and recycling treatment method for zinc-containing waste acid in a hot-dip galvanizing process, characterized in that: a zinc stripping additive and an iron remover are sequentially added to the zinc-containing waste acid and then subjected to electrolytic treatment, the zinc stripping additive is a mixture of a wetting agent and a corrosion inhibitor, the mass ratio of the wetting agent to the corrosion inhibitor is 1:5-20, and the addition amount of the zinc stripping additive is 0.01-10g / L. Preferably, as an improvement, the wetting agent is at least one of sodium dodecylbenzenesulfonate, sodium lauryl sulfate, OP-10, Tween, and fluorosurfactant.

[0006] Preferably, as an improvement, the corrosion inhibitor is at least one of mercaptobenzothiazole, benzotriazole, quinoline, and EDTA.

[0007] Preferably, as an improvement, the amount of the zinc stripping additive added is 0.1-5 g / L.

[0008] Preferably, as an improvement, the iron remover is at least one of phosphate, xanthate, dithiocarbamate, sodium sulfide, and oxalic acid.

[0009] In this technical solution, the selection of iron remover has a key influence on the iron ion precipitation effect and the subsequent iron-zinc separation effect. During the experiment, it was found that when phosphoric acid and oxalic acid were mixed in a mass ratio of 1:2, and potassium phosphate, oxalic acid and dithiocarbamate were mixed in a mass ratio of 1:1.5:1, the effect was outstanding.

[0010] Preferably, as an improvement, the amount of the iron remover added is 1-40 g / L.

[0011] Preferably, as an improvement, the iron removal process is stirred, with a stirring speed of 10-500 rpm, a stirring temperature of 50-100° C., a reaction pH of 0.5-4.0, and a reaction time of 1-10 h.

[0012] Preferably, as an improvement, the stirring speed is 50-200 rpm, the stirring temperature is 70-95° C., the reaction pH is 1-3, and the reaction time is 2-5 h.

[0013] Preferably, as an improvement, the electrolysis temperature during the electrolysis process is 10-50°C, and the current density is 100-10000A / m 2 When the zinc ion concentration in the waste liquid is lower than 60g / L, the electrolysis is stopped, and an electrolysis catalyst is added during the electrolysis. The electrolysis catalyst is at least one of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone, and the amount of the electrolysis catalyst added is 0.1-5g / L.

[0014] Preferably, as an improvement, the electrolysis temperature during the electrolysis process is 20-30°C, and the current density is 300-600A / m 2 When the zinc ion concentration in the waste liquid is lower than 40-50 g / L, the electrolysis is stopped. The electrolysis catalyst is a composite of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone in a mass ratio of 1:2:0.1, and the amount of electrolysis catalyst added is 0.1-5 g / L.

[0015] The principles and advantages of this solution are as follows: Currently, the separation of zinc and iron ions remains an urgent but difficult problem within the industry. This is due to the similar chemical properties of zinc and iron. On the one hand, both zinc and iron ions combine with hydroxide ions to form hydroxide precipitates. Within a certain pH range, the solubility of zinc hydroxide (Zn(OH)2) and iron hydroxide (Fe(OH)3) is relatively low, and the formation and solubility equilibrium of the precipitates are significantly affected by the solution pH. When adjusting the solution pH to precipitate the iron ions, zinc ions may also precipitate simultaneously, or iron ions may have already partially precipitated by the time zinc ions begin to precipitate, making it difficult to completely separate the two using simple precipitation separation methods. On the other hand, both can form complexes with many ligands, and the resulting complexes have similar stability. However, existing separation methods have significant limitations: ① Precipitation: As mentioned above, due to the similar properties of the hydroxide precipitates of the two, complete separation is difficult to achieve using pH-adjusted precipitation methods. Even if the pH is controlled within a certain range and the iron hydroxide is precipitated first, coprecipitation can occur during the precipitation process. This means that zinc ions may be adsorbed by the iron hydroxide precipitate or entrained in the precipitate, causing some of the zinc ions to precipitate as well, thus affecting the separation effect. ② Ion exchange method: The difference in the exchange capacity of ion exchange resins for zinc and iron ions is not significant enough. Although ion exchange resins can selectively exchange different ions based on factors such as charge and radius, the similarities in properties such as charge and radius between zinc and iron ions result in similar adsorption and elution behaviors on ion exchange resins, making efficient separation difficult via ion exchange. ③ Solvent extraction method: Finding an extractant with significantly different extraction capacities for zinc and iron ions is difficult. Common extractants often fail to achieve ideal separation results when extracting zinc and iron ions because their extraction equilibrium constants for the two ions are not sufficiently different. This results in both ions being extracted into the organic phase during extraction, or making it difficult to completely separate them during back extraction.

[0016] Based on the above problems, in this technical solution, the inventor has comprehensively upgraded and optimized the treatment process: using zinc stripping additives to carry out zinc stripping treatment, so that the zinc ion concentration in the waste liquid after zinc stripping is 100g / L-200g / L, and the iron ion content in the waste liquid is about 1g / L-20g / L. In this process, the key points and difficulties of research and development are: ① In the zinc stripping stage, in order to reduce the difficulty of subsequent iron removal, the purity of the final electrolytic zinc is increased, and the iron substrate is subjected to corrosion inhibition in the zinc stripping stage. However, the inventor found that this would lead to a simultaneous reduction in the speed of zinc stripping. Based on this, the inventor determined that the key to research and development is to achieve differentiated dissolution of zinc ions and iron ions. Based on this, the inventor, through the combination of corrosion inhibitors and wetting agents, optimizes the type and amount of corrosion inhibitors, and wets the zinc layer with a wetting agent, thereby accelerating the dissolution of the zinc layer and reducing the dissolution of iron. By reducing the iron content from the front end, the difficulty of subsequent iron treatment is reduced. ② During the iron removal stage, this solution optimizes the type and amount of iron remover and the ratio of the composition to ensure that the iron remover selectively reacts only with iron ions and not with zinc ions. In addition, by optimizing the reaction conditions (temperature, pH, time) during the iron removal reaction, the particle size of the reactants is reversely regulated to ensure the filtration effect, thereby ensuring the purity of the zinc and improving the electrolysis efficiency. In addition, the anode plate of this technical solution uses a special insoluble alloy plate or non-metallic plate to avoid the oxidative dissolution of the anode plate during the electrolysis process, and to prevent the metal elements in the anode plate from co-precipitating into the electrolytic zinc at the cathode, thereby further ensuring the purity of the zinc.

[0017] During the technology development phase, the inventors also tried to use oxidants such as hydrogen peroxide to oxidize all the divalent iron ions into trivalent iron ions, and then use caustic soda or ammonia to adjust the pH to above 3.0. At this time, the trivalent iron ions are hydrolyzed into ferric hydroxide and precipitated, and then filtered. However, there are problems: ferric hydride is a colloid, some of which have a particle size of even less than 100nm and can even penetrate laboratory filter paper, making it impossible to mass produce; and a large amount of colloid has strong water absorption and high viscosity, which can easily clog the filtration equipment and cannot be operated industrially. However, the reactants obtained by the optimized process of this technical solution are large-particle crystals, which are easy to operate and filter.

[0018] In summary, the beneficial effects of this technical solution are: 1. Environmentally friendly: This technical solution produces almost no acid mist during the waste acid zinc stripping process, which can improve the air quality in the workshop.

[0019] 2. Resource recycling: After the electrolysis is completed in this technical solution, the metal ions in the acid solution have been removed and the acid strength has been restored. The acid solution can return to the above-mentioned zinc stripping process to continue zinc stripping. This is a closed loop, reciprocating cycle, and zero waste acid throughout the process.

[0020] 3. Economic benefits: This technical solution can realize the recovery of zinc, reduce resource waste, and has a low iron ion content, which can ensure that the electrolysis efficiency of the treated waste acid is 98%.

[0021] 4. No need for wastewater treatment: This technical solution realizes closed-loop circulation and there is no wastewater discharge, thus eliminating the need for wastewater treatment and reducing environmental protection costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a record diagram of the zinc stripping process in an embodiment of the present invention.

[0023] Figure 2 This is a diagram showing the effect of iron removal in an embodiment of the present invention.

[0024] Figure 3 Schematic diagram of the zinc plate after electrolysis in an embodiment of the present invention.

[0025] Figure 4 The present invention is a process flow chart of the regeneration and recycling treatment method of zinc-containing waste acid in the hot-dip galvanizing process. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; and the materials, reagents, etc. used are all commercially available.

[0027] Program Overview: The zinc-containing waste acid in this embodiment is an organic acid or an inorganic acid or one or more combinations thereof, specifically at least one of nitric acid, hydrochloric acid, sulfuric acid, citric acid, gluconic acid, aminoacetic acid, and glycolic acid. The concentration of the zinc-containing waste acid is 1%-50%, and optimally 10%-30%.

[0028] A method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process comprises the following steps: Step 1, zinc stripping: adding a zinc stripping additive to the zinc-containing waste acid, wherein the zinc stripping additive is a mixture of a wetting agent and a corrosion inhibitor, the mass ratio of the wetting agent to the corrosion inhibitor is 1:5-20, and the addition amount of the zinc stripping additive is 0.01-10 g / L; The zinc ion concentration in the wastewater after zinc stripping is 100-200g / L, and the iron ion concentration is 1-20g / L; The wetting agent is at least one of sodium dodecylbenzenesulfonate, sodium lauryl sulfate, OP-10, Tween, and fluorosurfactant; The corrosion inhibitor is at least one of mercaptobenzothiazole, benzotriazole, quinoline, and EDTA; Step 2, iron removal: adding an iron remover to the zinc-containing waste acid after zinc stripping and stirring, the iron remover is at least one of phosphate, xanthate, dithiocarbamate, sodium sulfide, and oxalic acid, and the amount of the iron remover added is 1-40 g / L; the stirring speed is 10-500 rpm, the stirring temperature is 50-100 ° C, the reaction pH is 0.5-4.0, and the reaction time is 1-10 h; The iron ion content in the waste liquid after the above iron removal process is less than 1g / L; Step 3: Electrolysis: The anode plate used is any of the insoluble metal materials such as titanium plate, lead plate, graphite plate, lead alloy plate, etc., and the cathode plate is zinc plate, aluminum plate or stainless steel plate; the electrolysis temperature is 10-50℃, and the current density is 100-10000A / m 2 ; When the zinc ion concentration in the waste liquid is lower than 60g / L, the electrolysis is stopped; an electrolysis catalyst is added during the electrolysis, and the electrolysis catalyst is at least one of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone, preferably a composite of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone in a mass ratio of 1:2:0.1; the amount of the electrolysis catalyst added is 0.1-5g / L.

[0029] After the electrolysis is completed, the waste liquid is restored to the zinc stripping capacity after the metal ions are removed, and returns to step 1 to continue zinc stripping.

[0030] Example 1 A method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process comprises the following steps: Step 1: zinc stripping: adding a zinc stripping additive to the zinc-containing waste acid, wherein the zinc stripping additive is a mixture of a wetting agent and a corrosion inhibitor, the mass ratio of the wetting agent to the corrosion inhibitor is 1:5, and the addition amount of the zinc stripping additive is 5g / L; After zinc stripping, the concentration of zinc ions in the wastewater is 150 g / L and the concentration of iron ions is 16 g / L. The wetting agent is a mixture of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate in a mass ratio of 1:1.

[0031] The corrosion inhibitor is EDTA.

[0032] Step 2: Iron removal: add an iron remover to the zinc-containing waste acid after zinc stripping and stir. The iron remover is a mixture of potassium phosphate, oxalic acid and dithiocarbamate in a mass ratio of 1:1.5:1. The amount of the iron remover added is 5 g / L; the stirring speed is 150 rpm, the stirring temperature is 85°C, and the reaction pH is 2.5; The iron ion content in the waste liquid after the above iron removal process is less than 0.1g / L; Step 3: Electrolysis: The anode plate used is a graphite plate, and the cathode plate is a zinc plate; the electrolysis temperature is 25°C, and the current density is 450A / m 2When the zinc ion concentration in the waste liquid is lower than 45g / L, the electrolysis is stopped, and an electrolysis catalyst is added during the electrolysis. The electrolysis catalyst is a composite of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone in a mass ratio of 1:2:0.1, and the amount of electrolysis catalyst added is 2g / L.

[0033] After the electrolysis is completed, the waste liquid is restored to the zinc stripping capacity after the metal ions are removed, and returns to step 1 to continue zinc stripping.

[0034] Example 2 A method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process comprises the following steps: Step 1, zinc stripping: adding a zinc stripping additive to the zinc-containing waste acid, wherein the zinc stripping additive is a mixture of a wetting agent and a corrosion inhibitor, the mass ratio of the wetting agent to the corrosion inhibitor is 1:20, and the addition amount of the zinc stripping additive is 10 g / L; The zinc ion concentration in the wastewater after zinc stripping is 100-200g / L, and the iron ion concentration is 1-20g / L; The wetting agent is OP-10; the corrosion inhibitor is a mixture of mercaptobenzothiazole and benzotriazole in a mass ratio of 2:1; Step 2: Iron removal: add an iron remover to the zinc-containing waste acid after zinc stripping and stir. The iron remover is a mixture of phosphoric acid and oxalic acid in a mass ratio of 1:2. The amount of the iron remover added is 40 g / L; the stirring speed is 500 rpm, the stirring temperature is 70°C, and the reaction pH is 3; The iron ion content in the waste liquid after the above iron removal process is less than 1g / L; Step 3: Electrolysis: The anode plate used is titanium plate, and the cathode plate is stainless steel plate; the electrolysis temperature is 50℃, and the current density is 100A / m 2 When the zinc ion concentration in the waste liquid is lower than 60g / L, the electrolysis is stopped, and an electrolysis catalyst is added during the electrolysis. The electrolysis catalyst is a composite of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone in a mass ratio of 1:2:0.1, and the amount of electrolysis catalyst added is 5g / L.

[0035] After the electrolysis is completed, the waste liquid is restored to the zinc stripping capacity after the metal ions are removed, and returns to step 1 to continue zinc stripping.

[0036] Comparative Example 1 The difference between this comparative example and Example 1 is that in this comparative example, the zinc stripping additive is a mixture of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate in a mass ratio of 1:1.

[0037] Comparative Example 2 The difference between this comparative example and Example 1 is that in this comparative example, the zinc stripping additive is EDTA.

[0038] Comparative Example 3 The difference between this comparative example and Example 1 is that in this comparative example, the amount of the zinc stripping additive added is 12 g / L.

[0039] Comparative Example 4 The difference between this comparative example and Example 1 is that in this comparative example, no stirring treatment is performed during the iron removal process.

[0040] Comparative Example 5 The difference between this comparative example and Example 1 is that in this comparative example, no electrolysis catalyst is added.

[0041] Comparative Example 6 The difference between this comparative example and Example 1 is that in this comparative example, the anode plate during electrolysis is also an aluminum plate.

[0042] Comparative Example 7 The difference between this comparative example and Example 1 is that in this comparative example, the reaction temperature during iron removal is 45°C.

[0043] Comparative Example 8 The difference between this comparative example and Example 1 is that in this comparative example, the reaction temperature during iron removal is 110°C.

[0044] Comparative Example 9 The difference between this comparative example and Example 1 is that in this comparative example, the reaction time for iron removal is 0.5 h.

[0045] Comparative Example 10 The difference between this comparative example and Example 1 is that in this comparative example, the reaction time for iron removal is 10.5 h.

[0046] Experimental Example 1 Observation Record The acid mist generation during the zinc stripping process of Example 1, the iron precipitation during the iron removal process, and the zinc plate after electrolysis were recorded. The results are as follows: Figure 1-Figure 3 As shown. Figure 1 It shows that no acid mist is generated during the zinc stripping process; Figure 2 The left shows the iron sedimentation situation. Figure 2 The middle is iron slag, Figure 2 The right is the spent acid after iron removal; Figure 3 It shows that zinc is enriched on the plate.

[0047] Experimental Example 2 Zinc ions are continuously reduced to zinc metal on the cathode plate, deposited to form zinc plates, and peeled off from the cathode plate after electrolysis. The chemical composition of the enriched zinc after treatment in Example 1 was tested, and the test results are shown in Table 1: Table 1

[0048] Experimental Example 3 The purity and electrolysis efficiency of the zinc obtained by stripping the cathode zinc plate after electrolysis in the above embodiments and comparative examples were tested. The electrolysis efficiency test method was to select a 0.01 square meter cathode plate, weigh it and record it as M1, then use a current of 5 amperes, and after electrolysis for one hour, blow dry the cathode plate and weigh it and record it as M2.

[0049] Calculation: Electrolysis efficiency = M2-M1 / 5x1.22, where 1.22 means the electrochemical equivalent of zinc ions is 1.22 (g / A·h). That is, when the current is 1 ampere and the electrolysis is carried out for 1 hour, assuming the electrolysis efficiency is 100%, the weight of the electrolyzed zinc metal is 1.22g.

[0050] The test results are shown in Table 2. The results demonstrate that the embodiments of the present invention are able to maintain high zinc purity and electrolysis efficiency, achieving excellent iron-zinc separation. Furthermore, the selection and amount of zinc stripping additives, the type of iron remover, the iron removal conditions, and the type of anode plate used during electrolysis all have a certain impact on the separation effect. Separation failure can occur when an aluminum anode plate is used during electrolysis, or when the iron removal reaction temperature is too low or too high.

[0051] Table 2

[0052] Experimental Example 4 The iron ion content and the particle size of the iron precipitate after iron removal in each embodiment of the present invention and the comparative example were tested using the following test method: Iron ion content: o-phenanthroline spectrophotometry; Iron precipitate particle size: laser particle size analyzer.

[0053] The test was repeated three times for each group, and the test results are shown in Table 3: The results show that the present invention can achieve a good separation effect, the iron content after separation is low, and the particle size of the iron precipitate is relatively large, which can reduce the difficulty of separation.

[0054] Table 3

[0055] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process, characterized in that: A zinc stripping additive and an iron remover are sequentially added to the zinc-containing waste acid and then subjected to electrolytic treatment. The zinc stripping additive is a mixture of a wetting agent and a corrosion inhibitor, the mass ratio of the wetting agent to the corrosion inhibitor is 1:5-20, and the addition amount of the zinc stripping additive is 0.01-10 g / L.

2. The regeneration and recycling method for treating waste zinc acid in a hot-dip galvanizing process according to claim 1, wherein: The wetting agent is at least one of sodium dodecylbenzene sulfonate, sodium lauryl sulfate, OP-10, Tween, and fluorosurfactant.

3. The regeneration and recycling method for treating waste zinc acid in a hot-dip galvanizing process according to claim 2, wherein: The corrosion inhibitor is at least one of mercaptobenzothiazole, benzotriazole, quinoline and EDTA.

4. The regeneration and recycling method for treating waste zinc acid in a hot-dip galvanizing process according to claim 3, wherein: The addition amount of the zinc stripping additive is 0.1~5g / L.

5. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 4, characterized in that: The iron remover is at least one of phosphate, xanthate, dithiocarbamate, sodium sulfide, and oxalic acid.

6. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 5, characterized in that: The addition amount of the iron remover is 1-40 g / L.

7. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 6, characterized in that: The iron removal process is carried out by stirring, with a stirring speed of 10-500 rpm, a stirring temperature of 50-100° C., a reaction pH of 0.5-4.0, and a reaction time of 1-10 h.

8. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 7, characterized in that: The stirring speed is 50-200 rpm, the stirring temperature is 70-95° C., the reaction pH is 1-3, and the reaction time is 2-5 h.

9. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 8, characterized in that: The electrolysis temperature of the electrolysis process is 10-50°C, and the current density is 100-10000A / m 2 When the zinc ion concentration in the waste liquid is lower than 60g / L, the electrolysis is stopped, and an electrolysis catalyst is added during the electrolysis. The electrolysis catalyst is at least one of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone, and the amount of the electrolysis catalyst added is 0.1-5g / L.

10. The method for regenerating and recycling waste acid containing zinc in a hot-dip galvanizing process according to claim 9, characterized in that: The electrolysis temperature of the electrolysis process is 20-30°C, and the current density is 300-600A / m 2 When the zinc ion concentration in the waste liquid is lower than 40-50 g / L, the electrolysis is stopped. The electrolysis catalyst is a composite of polyethylene glycol, sodium methylene dinaphthalene sulfonate, and benzyl acetone in a mass ratio of 1:2:0.1, and the added amount of the electrolysis catalyst is 0.1-5 g / L.

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