Recycling process of copper acid waste liquid based on high-concentration hydrogen peroxide

Abstract

The invention discloses a copper acid waste liquid recovery treatment process based on high-concentration hydrogen peroxide, and belongs to the technical field of copper acid waste liquid treatment.The copper acid waste liquid recovery treatment process comprises the following steps that copper acid waste liquid and concentrated sulfuric acid are mixed and then conveyed to a mixed decomposing tank, heating and heat preservation treatment are conducted, and copper acid waste liquid with hydrogen peroxide removed is obtained; adjusting the pH value of the hydrogen peroxide-removed copper acid waste liquid, uniformly mixing the hydrogen peroxide-removed copper acid waste liquid with an extraction agent, standing for layering to obtain a low-copper waste liquid and a high-copper extraction liquid, adding a sulfuric acid solution into the high-copper extraction liquid to obtain a low-copper extraction liquid and a copper sulfate solution, and feeding the low-copper extraction liquid into an extraction tank for recycling; the copper sulfate solution is electrolyzed, metal copper and a sulfuric acid solution are obtained, and the sulfuric acid solution is recycled in a back extraction tank; the ion exchange resin is adopted to treat the low-copper waste liquid, the recovery treatment process of the copper acid waste liquid with high-concentration hydrogen peroxide is completed, and the treatment process is simple in operation step, high in safety, low in cost and good in treatment effect, and does not involve the use of additives such as enzymes.

Description

Technical Field

[0001] The invention belongs to the technical field of copper acid waste liquid treatment, and in particular relates to a recovery and treatment process of copper acid waste liquid based on high-concentration hydrogen peroxide. Background Art

[0002] The copper etching process is an important process in the production of PCBs and panels. In this process, a large amount of copper acid waste liquid containing hydrogen peroxide and divalent copper ions will be produced. Copper acid waste liquid cannot be discharged directly, and the chemical components that are harmful to the environment need to be treated, especially hydrogen peroxide and copper ions.

[0003] At present, the treatment of hydrogen peroxide in copper acid waste liquid mostly uses the method of adding alkali or enzyme to reduce, and the treatment scheme for copper is mainly sedimentation, extraction and electrolysis. There are mainly three processes for treating hydrogen peroxide and copper ions in copper acid waste liquid at the same time:

[0004] 1) Dilution-sedimentation process: The concentration of hydrogen peroxide and copper ions in the copper acid waste liquid is diluted by adding a large amount of waste liquid that does not contain copper ions and hydrogen peroxide, and then alkali is added to it to increase the pH value of the system. Under high pH conditions, the hydrogen peroxide in the waste liquid will decompose and the copper ions will precipitate.

[0005] 2) Extraction-electrolysis-decomposition of hydrogen peroxide process: The copper ions in the copper acid waste liquid are extracted / stripped into a sulfuric acid solution of a certain concentration to obtain a copper sulfate solution. The copper sulfate is electrolyzed to obtain elemental copper, and the low-copper waste liquid is diluted and enzymes are added to decompose hydrogen peroxide.

[0006] 3) Decomposition of hydrogen peroxide - acid dilution - electrolysis process: decompose hydrogen peroxide by kettle heating, then dilute with sulfuric acid to reduce the COD concentration in the waste liquid, and finally electrolyze to separate the copper element.

[0007] However, when the above three processes are used to treat copper acid waste liquid containing high concentration of hydrogen peroxide, the following problems often occur:

[0008] 1. The dilution-alkali precipitation method requires a significant dilution of the copper acid waste liquid. Considering the concentration of hydrogen peroxide in the waste liquid and safety requirements, the dilution ratio is often more than 50 times, resulting in high treatment costs and low efficiency.

[0009] 2. When the extraction-electrolysis method is used to recover copper ions, it is difficult to reduce the copper ion concentration after treatment to below the discharge standard by extraction due to the presence of a large amount of organic chelates in the waste liquid;

[0010] 3. High concentration of hydrogen peroxide has great safety risks. The solution of first recovering copper and then using enzymes to degrade hydrogen peroxide will greatly increase the safety cost of the process;

[0011] 4. The oxidizing property of high-concentration hydrogen peroxide will cause it to be corrosive to equipment and pipelines. Treating waste liquid containing high-concentration hydrogen peroxide will increase the anti-corrosion cost of equipment;

[0012] 5. The decomposition of hydrogen peroxide - acid dilution - electrolysis process is adopted. The decomposition time of hydrogen peroxide is too long, the decomposition efficiency is low, and some hydrogen peroxide still remains in the waste liquid after decomposition; even if the waste liquid is diluted several times with sulfuric acid before electrolysis, the organic matter it contains will still affect the electrolytic copper and reduce the service life of the electrode; and the electrolysis efficiency is low, so that the copper ions in the waste liquid are far from meeting the safe emission standards. Summary of the invention

[0013] The purpose of the present invention is to provide a recovery and treatment process of copper acid waste liquid based on high concentration hydrogen peroxide, so as to solve the problems of high treatment cost and poor effect in the existing copper acid waste liquid recovery and treatment process.

[0014] The purpose of the present invention can be achieved through the following technical solutions:

[0015] A recovery and treatment process for copper acid waste liquid based on high concentration hydrogen peroxide, the treatment process comprising the following steps:

[0016] (1) Acid addition-heating method to decompose hydrogen peroxide: the copper acid waste liquid is mixed with concentrated sulfuric acid and transported to a mixed decomposition tank, and heated and insulated to obtain the copper acid waste liquid with hydrogen peroxide removed;

[0017] The copper acid waste liquid is first mixed with concentrated sulfuric acid through a pipeline mixer, and then enters the heating zone of the mixed decomposition tank. During this period, the hydrogen peroxide in the copper acid waste liquid begins to self-heat and decompose rapidly, and then gradually flows into the insulation zone. The insulation zone ensures efficient decomposition while also ensuring the stability and safety of hydrogen peroxide decomposition. Finally, the waste liquid with hydrogen peroxide completely decomposed flows out of the mixed decomposition tank through a pipeline to obtain copper acid waste liquid with hydrogen peroxide removed.

[0018] (2) Extraction / re-extraction: adjusting the pH value of the copper acid waste liquid after hydrogen peroxide removal and mixing it evenly with the extractant, allowing it to stand for stratification to obtain low-copper waste liquid and high-copper extract, adding sulfuric acid solution to the high-copper extract for re-extraction to obtain low-copper extract and copper sulfate solution, and the low-copper extract is returned to the extraction tank for recycling;

[0019] (3) Electrolysis of copper sulfate: electrolyzing the copper sulfate solution to obtain metallic copper and sulfuric acid solution, and the sulfuric acid solution is sent to the stripping tank for recycling;

[0020] (4) Resin adsorption: Use ion exchange resin to treat low-copper waste liquid and complete the recovery and treatment process of copper acid waste liquid with high concentration of hydrogen peroxide.

[0021] Furthermore, in step (1), the amount of concentrated sulfuric acid added is 0.5% to 5% of the mass of the copper acid waste liquid. If the amount of concentrated sulfuric acid added is too low, the decomposition of hydrogen peroxide is unstable and the safety cannot be guaranteed; if the amount of concentrated sulfuric acid added is too high, the decomposition rate of hydrogen peroxide is greatly reduced, and too much acid will reduce the subsequent recovery effect of copper ions.

[0022] Furthermore, in step (1), the interior of the mixing and decomposing tank is divided into curved channels by partitions, and the mixing and decomposing tank includes a heating zone and a heat preservation zone, the temperature of the heating zone is 70°C to 98°C, and the temperature of the heat preservation zone is 80°C to 98°C.

[0023] Furthermore, the heating and heat preservation treatment time in step (1) is 5 minutes to 20 minutes.

[0024] Furthermore, the mass fraction of the concentrated sulfuric acid is 95% to 98%.

[0025] Furthermore, the pH value of the copper acid waste liquid is 2-5, the copper ion content is 2000ppm-5000ppm, and the hydrogen peroxide content is 5wt%-22wt%.

[0026] Furthermore, the content of hydrogen peroxide in the copper acid waste liquid for removing hydrogen peroxide is less than 0.1wt%.

[0027] Furthermore, the specific operation of step (2) is as follows:

[0028] The copper acid waste liquid after hydrogen peroxide removal is transported to a pretreatment tank, concentrated sulfuric acid is added to the pretreatment tank to adjust the pH value to 1-3, and acidified copper acid waste liquid after hydrogen peroxide removal is obtained; the acidified copper acid waste liquid after hydrogen peroxide removal is transported to an extraction tank, an extractant is added to the extraction tank, stirred evenly, allowed to stand for stratification, and after phase separation, low-copper waste liquid and high-copper extract are obtained; the high-copper extract is transported to a back-extraction tank, sulfuric acid solution is added to the back-extraction tank, stirred evenly, allowed to stand for stratification, and low-copper extract and copper sulfate solution are obtained, and the low-copper extract is recycled to the extraction tank.

[0029] Furthermore, in step (2), the mass ratio of the copper acid waste liquid except hydrogen peroxide to the extractant is 1 to 10:1.

[0030] Furthermore, in step (2), the mass ratio of the high copper extract to the sulfuric acid solution is 1 to 5:1, and the mass fraction of the sulfuric acid solution is 10% to 30%.

[0031] Furthermore, the extractant is one of Lix54-100, Lix84, Lix84i, Lix860, Lix984, P204, P507, N-910, N1923, N902, TBP (tributyl phosphate) and M5640.

[0032] Furthermore, the copper ion content in the low-copper extract is 10ppm to 50ppm, and the copper sulfate content in the copper sulfate solution is ≥20000ppm.

[0033] Furthermore, in step (3), the electrolysis temperature is 40°C to 50°C, and the current density is 200A / m 2 ~250A / m 2 , the electrolysis voltage is 3V~5V, and the electrolysis time is 8h~15h.

[0034] Furthermore, in step (3), the positive electrode of the electrolytic cell is connected to the electrolyte, the negative electrode is connected to the copper sulfate solution, and a reverse osmosis diaphragm is arranged between the copper sulfate solution and the electrolyte. During operation, oxygen is generated at the positive electrode and elemental copper is generated at the negative electrode.

[0035] Furthermore, the specific operation of step (4) is as follows: transporting the low-copper waste liquid to a resin tower filled with ion exchange resin at a flow rate of 0.5 BV / h to 2.8 BV / h and a temperature of 15°C to 50°C, wherein the copper ions in the low-copper waste liquid are adsorbed by the ion exchange resin, and the effluent from the resin tower is concentrated in a storage tank to obtain treated waste liquid; when the ion exchange resin adsorption reaches saturation, stopping the introduction of the low-copper waste liquid, adding concentrated sulfuric acid to the resin tower, and using concentrated sulfuric acid to clean the ion exchange resin to restore the adsorption capacity of the ion exchange resin, and obtaining a cleaning liquid to go to a pretreatment tank to participate in the adjustment of the pH value.

[0036] Furthermore, the model of the ion exchange resin is one of LSC-485, LSC-495, LSC-855, LX-1850H, LX-1850NH, 001×7 and LX-300C.

[0037] Furthermore, the copper ion content in the treated waste liquid is ≤0.5ppm.

[0038] Beneficial effects of the present invention:

[0039] 1. The present invention adopts an acid addition-heating method to decompose hydrogen peroxide, and then adopts an extraction-electrolysis method to recover the metallic copper in the copper acid waste liquid after the hydrogen peroxide is removed, and finally adopts an ion exchange resin adsorption method to adsorb and treat a small amount of copper ions in the low-copper waste liquid to meet the emission standards. The process of the present invention has simple operation steps, high safety, does not involve the use of additives such as enzymes, has low cost, and has good treatment effect.

[0040] 2. The present invention adopts an acid addition-heating method to decompose high-concentration hydrogen peroxide in copper acid waste liquid. The method is safe, stable and efficient. By adjusting the acid addition ratio, heating temperature and treatment time, the decomposition time and intensity of hydrogen peroxide in copper acid waste liquid with different copper ion concentrations can be effectively adjusted; compared with the decomposition of hydrogen peroxide by heating only, the acid addition-heating method can effectively control the intensity of the reaction, can better treat high-concentration hydrogen peroxide, and improve production safety.

[0041] 3. The copper acid waste liquid of the present invention is continuously heated to decompose hydrogen peroxide through a mixed decomposition tank, which greatly improves the decomposition efficiency of hydrogen peroxide while ensuring the safety of decomposition, and can quickly and effectively remove hydrogen peroxide in the copper acid waste liquid.

[0042] 4. The present invention preferentially treats hydrogen peroxide in copper acid waste liquid, effectively avoiding its corrosion to equipment, pipelines and materials in the remaining steps, and greatly reducing equipment corrosion protection costs and material costs.

[0043] 5. The present invention selects an efficient extractant and adopts an extraction-electrolysis method to recover metallic copper in copper acid waste liquid, thereby avoiding the interference of organic matter in the copper acid waste liquid in direct electrolysis and dehydrogenation of copper acid waste liquid, increasing the copper ion concentration in the electrolyte, and greatly improving the electrolysis efficiency; and in this system, both the extractant and the sulfuric acid solution can be recycled, greatly reducing the cost of copper recovery.

[0044] 6. The present invention adopts ion exchange resin treatment to effectively reduce the copper ion content in the copper acid waste liquid after extraction so that it meets the emission standards. At the same time, the resin tower is backwashed with a strong acid solution to effectively recover the adsorbed copper ions therein, and the ion exchange resin can be recycled to reduce the raw material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described below in conjunction with the accompanying drawings.

[0046] Figure 1 It is a flow chart of a recovery and treatment process of copper acid waste liquid based on high concentration hydrogen peroxide of the present invention;

[0047] Figure 2 It is a flow chart of the steps of decomposing hydrogen peroxide by the acid addition-heating method of the present invention;

[0048] Figure 3 is a flow chart of the extraction / strip extraction steps of the present invention;

[0049] Figure 4 It is a flow chart of the steps of electrolyzing copper sulfate of the present invention;

[0050] Figure 5 It is a flow chart of the resin adsorption step of the present invention. DETAILED DESCRIPTION

[0051] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] In the present application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, c can be single or multiple, respectively.

[0053] The terms used in the embodiments of the present application are only for the purpose of describing specific implementation rules, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the implementation rules of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0054] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0055] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0056] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0057] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0058] In view of the problems of high treatment cost and poor effect in the existing copper acid waste liquid recovery and treatment process, in order to solve the above problems to a certain extent, the present application provides a copper acid waste liquid recovery and treatment process based on high concentration hydrogen peroxide, the treatment process comprising the following steps:

[0059] (1) Acid addition-heating method to decompose hydrogen peroxide: the copper acid waste liquid is mixed with concentrated sulfuric acid and transported to a mixed decomposition tank, and heated and insulated to obtain the copper acid waste liquid with hydrogen peroxide removed;

[0060] The copper acid waste liquid is first mixed with concentrated sulfuric acid through a pipeline mixer, and then enters the heating zone of the mixed decomposition tank. During this period, the hydrogen peroxide in the copper acid waste liquid begins to self-heat and decompose rapidly, and then gradually flows into the insulation zone. The insulation zone ensures efficient decomposition while also ensuring the stability and safety of hydrogen peroxide decomposition. Finally, the waste liquid with hydrogen peroxide completely decomposed flows out of the mixed decomposition tank through a pipeline to obtain copper acid waste liquid with hydrogen peroxide removed.

[0061] (2) Extraction / re-extraction: adjusting the pH value of the copper acid waste liquid after hydrogen peroxide removal and mixing it evenly with the extractant, allowing it to stand for stratification to obtain low-copper waste liquid and high-copper extract, adding sulfuric acid solution to the high-copper extract for re-extraction to obtain low-copper extract and copper sulfate solution, and the low-copper extract is returned to the extraction tank for recycling;

[0062] (3) Electrolysis of copper sulfate: electrolyzing the copper sulfate solution to obtain metallic copper and sulfuric acid solution, and the sulfuric acid solution is sent to the stripping tank for recycling;

[0063] (4) Resin adsorption: Use ion exchange resin to treat low-copper waste liquid and complete the recovery and treatment process of copper acid waste liquid with high concentration of hydrogen peroxide.

[0064] In some embodiments, the amount of concentrated sulfuric acid added in step (1) is 0.5% to 5% of the mass of the copper acid waste liquid. In the exemplary embodiment, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4.0%, 4.5%, 5.0% and other typical but non-limiting mass ratios or the range between any two ratios. Within this mass ratio range, the decomposition of hydrogen peroxide is stable and will not affect the subsequent recovery effect of copper ions. It should be noted that the amount of concentrated sulfuric acid added should not exceed the above range. Otherwise, the amount of concentrated sulfuric acid added is too low, the decomposition of hydrogen peroxide is unstable, and the safety cannot be guaranteed; if the amount of concentrated sulfuric acid added is too high, the decomposition rate of hydrogen peroxide is greatly reduced, and too much acid will reduce the subsequent recovery effect of copper ions.

[0065] In some embodiments, the interior of the mixing and decomposition tank in step (1) is divided into a curved channel by a partition, including a heating zone and a heat preservation zone. The temperature of the heating zone is 70°C to 98°C. In the exemplary embodiment, it can be a typical but non-limiting temperature such as 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 98°C, or a range between any two temperatures; the temperature of the heat preservation zone is 80°C to 98°C. In the exemplary embodiment, it can be a typical but non-limiting temperature such as 80°C, 85°C, 90°C, 95°C, 98°C, or a range between any two temperatures.

[0066] In some embodiments, the heating and heat preservation treatment time in step (1) is 5 minutes to 20 minutes.

[0067] In some embodiments, the mass fraction of the concentrated sulfuric acid is 95% to 98%.

[0068] In some embodiments, the pH value of the copper acid waste liquid is 2-5, the copper ion content is 2000ppm-5000ppm, and the hydrogen peroxide content is 5wt%-22wt%.

[0069] In some embodiments, the hydrogen peroxide content in the copper acid waste liquid for removing hydrogen peroxide is less than 0.1 wt %.

[0070] In some embodiments, the specific operation of step (2) is:

[0071] The copper acid waste liquid after hydrogen peroxide removal is transported to a pretreatment tank, concentrated sulfuric acid is added to the pretreatment tank to adjust the pH value to 1-3, and acidified copper acid waste liquid after hydrogen peroxide removal is obtained; the acidified copper acid waste liquid after hydrogen peroxide removal is transported to an extraction tank, an extractant is added to the extraction tank, stirred evenly, allowed to stand for stratification, and after phase separation, low-copper waste liquid and high-copper extract are obtained; the high-copper extract is transported to a back-extraction tank, sulfuric acid solution is added to the back-extraction tank, stirred evenly, allowed to stand for stratification, and low-copper extract and copper sulfate solution are obtained, and the low-copper extract is recycled to the extraction tank.

[0072] In some embodiments, the mass ratio of the copper acid waste liquid except hydrogen peroxide to the extractant in step (2) is 1 to 10:1.

[0073] In some embodiments, the mass ratio of the high copper extract to the sulfuric acid solution in step (2) is 1 to 5:1, and the mass fraction of the sulfuric acid solution is 10% to 30%.

[0074] In some embodiments, the extractant is one of Lix54-100, Lix84, Lix84i, Lix860, Lix984, P204, P507, N-910, N1923, N902, TBP (tributyl phosphate) and M5640.

[0075] In some embodiments, the copper ion content in the low-copper extract is 10 ppm to 50 ppm, and the copper sulfate content in the copper sulfate solution is ≥ 20000 ppm.

[0076] In some embodiments, the electrolysis temperature in step (3) is 40°C to 50°C, and the current density is 200A / m 2 ~250A / m 2 , the electrolysis voltage is 3V~5V, and the electrolysis time is 8h~15h.

[0077] In some embodiments, in step (3), the positive electrode of the electrolytic cell is connected to the electrolyte, and the negative electrode is connected to the copper sulfate solution. A reverse osmosis membrane is arranged between the copper sulfate solution and the electrolyte. During operation, oxygen is generated at the positive electrode and elemental copper is generated at the negative electrode.

[0078] In some embodiments, the specific operation of step (4) is as follows: transporting the low-copper waste liquid to a resin tower filled with ion exchange resin at a flow rate of 0.5 BV / h to 2.8 BV / h and a temperature of 15°C to 50°C, wherein the copper ions in the low-copper waste liquid are adsorbed by the ion exchange resin, and the effluent from the resin tower is concentrated in a storage tank to obtain treated waste liquid; when the ion exchange resin adsorption reaches saturation, stopping the introduction of the low-copper waste liquid, adding concentrated sulfuric acid to the resin tower, and using concentrated sulfuric acid to clean the ion exchange resin to restore the adsorption capacity of the ion exchange resin, and the cleaning liquid is sent to the pretreatment tank to participate in the adjustment of the pH value.

[0079] In some embodiments, the ion exchange resin is one of LSC-485, LSC-495, LSC-855, LX-1850H, LX-1850NH, 001×7 and LX-300C.

[0080] In some embodiments, the copper ion content in the treated waste liquid is ≤0.5 ppm.

[0081] The copper acid waste liquid in the following Examples 1-5 and Comparative Examples 1-5 is copper-containing waste liquid from the panel industry, with a pH value of 3.5, a copper ion content of 5000 ppm, a hydrogen peroxide content of 18 wt %, and a mass fraction of concentrated sulfuric acid of 98.3%.

[0082] Example 1

[0083] See also Figure 1-Figure 5 As shown, a recovery and treatment process of copper acid waste liquid based on high concentration hydrogen peroxide comprises the following steps:

[0084] (1) Decomposing hydrogen peroxide by acid addition-heating method: 9 kg of copper acid waste liquid was mixed with 45 g of concentrated sulfuric acid and transported to a mixed decomposition tank. The mixed decomposition tank was divided into a curved channel by a partition, including a heating zone and a heat preservation zone. The temperature of the heating zone in the mixed decomposition tank was controlled to be 70° C., and the temperature of the heat preservation zone was controlled to be 80° C. After the heating and heat preservation treatment time was 20 min, the copper acid waste liquid with hydrogen peroxide removed was obtained. The copper acid waste liquid with hydrogen peroxide removed was sampled and tested, and no hydrogen peroxide was detected.

[0085] (2) Extraction / strip extraction: transport the copper acid waste liquid from hydrogen peroxide removal to a pretreatment tank, add concentrated sulfuric acid to the pretreatment tank to adjust the pH value to 3, and obtain acidified copper acid waste liquid from hydrogen peroxide removal; transport the acidified copper acid waste liquid from hydrogen peroxide removal to an extraction tank, add extractant N902 to the extraction tank, control the mass ratio of copper acid waste liquid from hydrogen peroxide removal to the extractant to be 1:1, stir evenly, stand for stratification, and obtain low-copper waste liquid and high-copper extract after phase separation; transport the high-copper extract to a stripping tank, add 10 wt % sulfuric acid solution to the stripping tank, the mass ratio of the high-copper extract to the 10 wt % sulfuric acid solution is 1:1, stir evenly, stand for stratification, and obtain low-copper extract and copper sulfate solution, and the low-copper extract is recycled to the extraction tank;

[0086] (3) Electrolysis of copper sulfate: The copper sulfate solution is transported to an electrolytic cell. The positive electrode of the electrolytic cell is connected to the electrolyte, and the negative electrode is connected to the copper sulfate solution. A reverse osmosis diaphragm is provided between the copper sulfate solution and the electrolyte. The electrolysis temperature is 40°C and the current density is 200A / m 2 , the electrolysis voltage is 3V, the electrolysis time is 8h, oxygen is produced at the positive electrode, and elemental copper is produced at the negative electrode, and 38g of metallic copper and sulfuric acid solution are obtained. The sulfuric acid solution is sent to the stripping tank for recycling;

[0087] (4) Resin adsorption: The low-copper waste liquid is transported to a resin tower filled with LSC-855 ion exchange resin at a flow rate of 0.5 BV / h and a temperature of 15°C. The copper ions in the low-copper waste liquid are adsorbed by the ion exchange resin, and the effluent from the resin tower is concentrated in a storage tank to obtain treated waste liquid. When the ion exchange resin adsorption reaches saturation, the low-copper waste liquid is stopped, concentrated sulfuric acid is added to the resin tower, and the ion exchange resin is cleaned with concentrated sulfuric acid to restore the adsorption capacity of the ion exchange resin. The cleaning liquid is sent to the pretreatment tank to participate in the adjustment of the pH value.

[0088] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.5 ppm, which met the emission standard.

[0089] Example 2

[0090] A process for recovering copper acid waste liquid based on high-concentration hydrogen peroxide comprises the following steps:

[0091] (1) Decomposing hydrogen peroxide by acid addition-heating method: 9 kg of copper acid waste liquid was mixed with 250 g of concentrated sulfuric acid and transported to a mixed decomposition tank. The mixed decomposition tank was divided into a curved channel by a partition, including a heating zone and a heat preservation zone. The temperature of the heating zone in the mixed decomposition tank was controlled to be 80° C., and the temperature of the heat preservation zone was controlled to be 85° C. After the heating and heat preservation treatment time was 10 min, the copper acid waste liquid with hydrogen peroxide removed was obtained. The copper acid waste liquid with hydrogen peroxide removed was sampled and tested, and no hydrogen peroxide was detected;

[0092] (2) Extraction / strip extraction: transport the copper acid waste liquid from hydrogen peroxide removal to a pretreatment tank, add concentrated sulfuric acid to the pretreatment tank to adjust the pH value to 2, and obtain acidified copper acid waste liquid from hydrogen peroxide removal; transport the acidified copper acid waste liquid from hydrogen peroxide removal to an extraction tank, add extractant N902 to the extraction tank, control the mass ratio of copper acid waste liquid from hydrogen peroxide removal to the extractant to be 5:1, stir evenly, stand for stratification, and obtain low-copper waste liquid and high-copper extract after phase separation; transport the high-copper extract to a stripping tank, add 20 wt % sulfuric acid solution to the stripping tank, the mass ratio of the high-copper extract to the 20 wt % sulfuric acid solution is 3:1, stir evenly, and obtain low-copper extract and copper sulfate solution; the low-copper extract is recycled to the extraction tank;

[0093] (3) Electrolysis of copper sulfate: The copper sulfate solution is transported to an electrolytic cell, the positive electrode of the electrolytic cell is connected to the electrolyte, and the negative electrode is connected to the copper sulfate solution. A reverse osmosis diaphragm is provided between the copper sulfate solution and the electrolyte. The electrolysis temperature is 45°C and the current density is 250A / m 2 , the electrolysis voltage is 5V, the electrolysis time is 12h, oxygen is produced at the positive electrode, and elemental copper is produced at the negative electrode, and 38g of metallic copper and sulfuric acid solution are obtained. The sulfuric acid solution is sent to the stripping tank for recycling;

[0094] (4) Resin adsorption: The low-copper waste liquid is transported to a resin tower filled with LSC-855 ion exchange resin at a flow rate of 1.8 BV / h and a temperature of 30°C. The copper ions in the low-copper waste liquid are adsorbed by the ion exchange resin, and the effluent from the resin tower is concentrated in a storage tank to obtain treated waste liquid. When the ion exchange resin adsorption reaches saturation, the low-copper waste liquid is stopped, concentrated sulfuric acid is added to the resin tower, and the ion exchange resin is cleaned with concentrated sulfuric acid to restore the adsorption capacity of the ion exchange resin. The cleaning liquid is sent to the pretreatment tank to participate in the adjustment of the pH value.

[0095] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.4 ppm, which met the emission standard.

[0096] Example 3

[0097] A process for recovering copper acid waste liquid based on high-concentration hydrogen peroxide comprises the following steps:

[0098] (1) Decomposing hydrogen peroxide by acid addition-heating method: 9 kg of copper acid waste liquid was mixed with 450 g of concentrated sulfuric acid and transported to a mixed decomposition tank. The mixed decomposition tank was divided into a curved channel by a partition, including a heating zone and a heat preservation zone. The temperature of the heating zone in the mixed decomposition tank was controlled to be 95° C., and the temperature of the heat preservation zone was controlled to be 93° C. After the heating and heat preservation treatment time was 5 min, the copper acid waste liquid with hydrogen peroxide removed was obtained. The copper acid waste liquid with hydrogen peroxide removed was sampled and tested, and no hydrogen peroxide was detected;

[0099] (2) Extraction / strip extraction: transport the copper acid waste liquid from hydrogen peroxide removal to a pretreatment tank, add concentrated sulfuric acid to the pretreatment tank to adjust the pH value to 1.8, and obtain acidified copper acid waste liquid from hydrogen peroxide removal; transport the acidified copper acid waste liquid from hydrogen peroxide removal to an extraction tank, add extractant N902 to the extraction tank, control the mass ratio of copper acid waste liquid from hydrogen peroxide removal to the extractant to be 10:1, stir evenly, stand for stratification, and obtain low-copper waste liquid and high-copper extract after phase separation; transport the high-copper extract to a stripping tank, add 30 wt % sulfuric acid solution to the stripping tank, the mass ratio of the high-copper extract to the 30 wt % sulfuric acid solution is 5:1, stir evenly, and obtain low-copper extract and copper sulfate solution; the low-copper extract is recycled to the extraction tank;

[0100] (3) Electrolysis of copper sulfate: The copper sulfate solution is transported to an electrolytic cell. The positive electrode of the electrolytic cell is connected to the electrolyte, and the negative electrode is connected to the copper sulfate solution. A reverse osmosis diaphragm is provided between the copper sulfate solution and the electrolyte. The electrolysis temperature is 50°C and the current density is 200A / m 2 , the electrolysis voltage is 5V, the electrolysis time is 15h, oxygen is produced at the positive electrode, and elemental copper is produced at the negative electrode, and 36g of metallic copper and sulfuric acid solution are obtained. The sulfuric acid solution is sent to the stripping tank for recycling;

[0101] (4) Resin adsorption: The low-copper waste liquid is transported to a resin tower filled with LSC-855 ion exchange resin at a flow rate of 2.8 BV / h and a temperature of 50°C. The copper ions in the low-copper waste liquid are adsorbed by the ion exchange resin, and the effluent from the resin tower is concentrated in a storage tank to obtain treated waste liquid. When the ion exchange resin adsorption reaches saturation, the low-copper waste liquid is stopped, concentrated sulfuric acid is added to the resin tower, and the ion exchange resin is cleaned with concentrated sulfuric acid to restore the adsorption capacity of the ion exchange resin. The cleaning liquid is sent to the pretreatment tank to participate in the adjustment of the pH value.

[0102] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.3 ppm, which met the emission standard.

[0103] Example 4

[0104] A recovery and treatment process for copper acid waste liquid based on high concentration hydrogen peroxide, compared with Example 1, the only difference is that the extractant used in the extraction / strip extraction process is extractant M5640, and the ion exchange resin is LSC-495 ion exchange resin.

[0105] The copper acid waste liquid obtained in this embodiment was sampled and tested, and no hydrogen peroxide was detected;

[0106] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.2 ppm, which met the emission standard.

[0107] Example 5

[0108] A recovery and treatment process for copper acid waste liquid based on high concentration hydrogen peroxide, compared with Example 1, the only difference is that the extractant used in the extraction / strip extraction process is extractant N-910, and the ion exchange resin used in the resin adsorption process is LSC-495 ion exchange resin.

[0109] The copper acid waste liquid obtained in this embodiment was sampled and tested, and no hydrogen peroxide was detected;

[0110] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.4 ppm, which met the emission standard.

[0111] Example 6

[0112] A recovery and treatment process of copper acid waste liquid based on high concentration hydrogen peroxide, compared with Example 1, the only difference is that the composition of the copper acid waste liquid is different. In this embodiment, the pH value of the copper acid waste liquid is 3.7, the copper ion content is 3000ppm, and the hydrogen peroxide content is 22wt%.

[0113] The copper acid waste liquid obtained in this embodiment was sampled and tested, and no hydrogen peroxide was detected;

[0114] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.2 ppm, which met the emission standard.

[0115] Example 7

[0116] A recovery and treatment process of copper acid waste liquid based on high concentration hydrogen peroxide, compared with Example 1, the only difference is that the composition of the copper acid waste liquid is different. In this embodiment, the pH value of the copper acid waste liquid is 4.2, the copper ion content is 2000ppm, and the hydrogen peroxide content is 20wt%.

[0117] The copper acid waste liquid obtained in this embodiment was sampled and tested, and no hydrogen peroxide was detected;

[0118] The treated waste liquid obtained in this example was sampled and tested, and the copper ion content in the treated waste liquid was 0.1 ppm, which met the emission standard.

[0119] Comparative Example 1

[0120] A process for recovering copper acid waste liquid based on high-concentration hydrogen peroxide comprises the following steps:

[0121] 36 g of concentrated sulfuric acid was added to 9 kg of copper acid waste liquid (the amount of concentrated sulfuric acid added was 0.4% of the mass of the copper acid waste liquid), and after mixing evenly, the mixture was passed into a mixing decomposition tank. The interior of the mixing decomposition tank was divided into a curved channel by a partition, including a heating zone and a heat preservation zone. The temperature of the heating zone was 70°C, and then it was violently decomposed by bubbling, and the bubbling amount was greater than 10 times the volume of the liquid. Considering the safety of the experiment, 9 kg of cold water (5°C) was directly added to the system, and the experiment was ended.

[0122] Comparative Example 2

[0123] A recovery and treatment process for copper acid waste liquid based on high concentration hydrogen peroxide, compared with Example 3, the only difference is that the "mixing 9 kg of copper acid waste liquid with 450 g of concentrated sulfuric acid and then conveying it to a mixed decomposition tank" in step (1) of Example 3 is adjusted to "mixing 9 kg of copper acid waste liquid with 540 g of concentrated sulfuric acid (the amount of concentrated sulfuric acid added is 6% of the mass of the copper acid waste liquid) and then conveying it to a mixed decomposition tank", and in step (2), the copper acid waste liquid does not need to be acidified in a pretreatment tank except for hydrogen peroxide, and directly enters an extraction tank;

[0124] The copper acid waste liquid obtained by removing hydrogen peroxide from the comparative example was sampled and tested, and the hydrogen peroxide content was 5.8wt%, and the pH value of the copper acid waste liquid obtained by removing hydrogen peroxide was less than 1.0;

[0125] The treated waste liquid obtained in this comparative example was sampled and tested, and the copper ion content in the treated waste liquid was 56 ppm, which did not meet the emission standards.

[0126] Comparative Example 3

[0127] A process for recovering copper acid waste liquid based on high-concentration hydrogen peroxide comprises the following steps:

[0128] 9 kg of copper acid waste liquid was added into the mixed decomposition tank. The interior of the mixed decomposition tank was divided into a curved channel by partitions, including a heating zone and a heat preservation zone. The temperature of the heating zone was 70°C. It immediately bubbled violently and decomposed. The bubbling amount was greater than 10 times the volume of the liquid. Considering the safety of the experiment, 9 kg of cold water (5°C) was directly added to the system and the experiment ended.

[0129] Comparative Example 4

[0130] A recovery and treatment process (dilution-sedimentation process) of copper acid waste liquid based on high concentration hydrogen peroxide comprises the following steps:

[0131] 9 kg of copper acid waste liquid was added to a degradation tank, and 450 kg of water was added and stirred evenly to obtain 459 kg of copper acid diluted liquid waste liquid; 200 kg of liquid alkali (36 wt% NaOH solution) was added to the copper acid diluted liquid waste liquid, the pH value of the system was increased to 9, and stirred evenly, and a small amount of bubbles were generated; after standing for 24 hours, 65 g of blue muddy precipitate was generated, which was filtered and the filtrate was sampled and measured, and no hydrogen peroxide was detected. The copper ion content was 15 ppm, which did not meet the emission standards.

[0132] Comparative Example 5

[0133] A recovery and treatment process for copper acid waste liquid based on high-concentration hydrogen peroxide (extraction-electrolysis-decomposition hydrogen peroxide process) comprises the following steps:

[0134] (1) Add 10 kg of copper acid waste liquid into a pretreatment tank, add 50 g of concentrated sulfuric acid to adjust the pH to 3; add the waste liquid with adjusted pH to an extraction tank, add 1 kg of extractant N902, stir for 5 min, and stand until phase separation, repeat three times to obtain a high-copper extract and a low-copper waste liquid;

[0135] (2) adding the high copper extract to the stripping tank, adding 3 kg of 10 wt % sulfuric acid solution, stirring for 5 min, standing until the phases are separated, and injecting the aqueous phase into the electrolytic tank;

[0136] (3) In the electrolytic cell, use a 5V electrode to electrolyze the copper sulfate solution at a temperature of 40°C and a current density of 200A / m 2 , electrolyzed for 8 hours, and finally 15g of metallic copper was obtained at the cathode;

[0137] (4) 20 g of sodium hydroxide was added to the low-copper waste liquid, the pH was adjusted to 6.5, 40 g of enzyme was added, the temperature was raised to 37°C, and the mixture was stirred and decomposed for 4 hours. After sampling and measurement, no hydrogen peroxide was detected and the copper ion content was 12 ppm, which did not meet the emission standards.

[0138] Comparative Example 6

[0139] A recovery and treatment process for copper acid waste liquid based on high-concentration hydrogen peroxide (hydrogen peroxide decomposition-acid dilution-electrolysis process) comprises the following steps:

[0140] (1) 10 kg of copper acid waste liquid (pH 4, copper ion content 5000 ppm, hydrogen peroxide content 5 wt%) was supplied to a heating device and heated to 80° C., and then introduced into a heat preservation tank for 7 hours to decompose hydrogen peroxide. After sampling and measurement, the hydrogen peroxide content was 1.1 wt%, thereby obtaining a primary treated copper acid waste liquid;

[0141] (2) 10 kg of 10 wt % sulfuric acid solution was added to the initially treated copper acid waste liquid, and after sufficient dilution, it was added to an electrolytic cell, a direct current of 500 A was passed, and constant current electrolysis was performed for 48 hours, and 45.8 g of metallic copper was collected at the negative electrode. The treated waste liquid was sampled and tested, and the hydrogen peroxide content was measured to be 0.4 wt %, and the copper ion content was 100 ppm, which did not meet the emission standards.

[0142] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0143] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for recovering copper acid waste liquid based on high concentration hydrogen peroxide, characterized in that: The following steps are involved: (1) mixing the copper acid waste liquid with concentrated sulfuric acid and transporting it to a mixing decomposition tank, heating and heat preservation treatment, to obtain the copper acid waste liquid with hydrogen peroxide removed; (2) adjusting the pH value of the copper acid waste liquid except hydrogen peroxide and mixing it evenly with the extractant, allowing it to stand for stratification to obtain a low-copper waste liquid and a high-copper extract, adding a sulfuric acid solution to the high-copper extract for back extraction to obtain a low-copper extract and a copper sulfate solution, and the low-copper extract is sent to an extraction tank for recycling; (3) electrolyzing the copper sulfate solution to obtain metallic copper and sulfuric acid solution, and the sulfuric acid solution is sent to a stripping tank for recycling; (4) The low-copper waste liquid is treated with ion exchange resin to complete the recovery and treatment of the copper acid waste liquid with high concentration of hydrogen peroxide.

2. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: In step (1), the amount of concentrated sulfuric acid added is 0.5% to 5% of the mass of the copper acid waste liquid.

3. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: In step (1), the interior of the mixing and decomposing tank is divided into curved channels by partitions, and the mixing and decomposing tank includes a heating zone and a heat preservation zone, the temperature of the heating zone is 70° C. to 98° C., and the temperature of the heat preservation zone is 80° C. to 98° C.

4. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: The heating and heat preservation treatment time in step (1) is 5 minutes to 20 minutes.

5. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: In step (2), the pH adjusting agent for adjusting the pH value of the copper acid waste liquid for removing hydrogen peroxide is concentrated sulfuric acid, and the pH value is adjusted to 1-3.

6. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: In step (2), the mass ratio of the copper acid waste liquid except hydrogen peroxide to the extractant is 1 to 10:

1.

7. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: In step (2), the mass ratio of the high copper extract to the sulfuric acid solution is 1 to 5:1, and the mass fraction of the sulfuric acid solution is 10% to 30%.

8. A process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1 or 6, characterized in that: The extractant is one of Lix54-100, Lix84, Lix84i, Lix860, Li x984, P204, P507, N-910, N1923, N902, TBP and M5640.

9. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: The electrolysis temperature is 40℃~50℃, and the current density is 200A / m 2 ~250A / m 2 , the electrolysis voltage is 3V~5V, and the electrolysis time is 8h~15h.

10. The process for recovering copper acid waste liquid based on high concentration hydrogen peroxide according to claim 1, characterized in that: The model of the ion exchange resin is one of LSC-485, LSC-495, LSC-855, LX-1850H, LX-1850NH, 001×7 and LX-300C.

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