A method for regenerating vanadium electrolyte waste solution

Abstract

The application provides a vanadium electrolyte waste liquid regeneration method, which uses vanadium battery waste liquid as raw material, filters insoluble impurities in the waste liquid through first filtration, adjusts the valence state of the electrolyte to be lower than trivalent through first electrolysis, avoids flocculation caused by high valence state of vanadium ions, adds a flocculating agent to stir and cause flocculation reaction, filters after flocculation of impurity ions, and electrolyzes the filtered vanadium electrolyte through an electrolysis device to remove copper ions introduced in the flocculating agent, so that the vanadium electrolyte is finally obtained, the whole method is simple in operation, low in energy consumption, pollution-free, high in efficiency and short in regeneration time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste electrolyte regeneration, in particular to a vanadium electrolyte waste liquid regeneration method. BACKGROUND

[0002] All-vanadium redox flow battery has the advantages of high energy conversion efficiency, adjustable capacity, long service life, high safety and environmental friendliness, and is mainly used for renewable energy power generation system matching energy storage equipment, peak shaving and valley filling device of power grid, uninterruptible power supply and emergency power supply system.

[0003] In the vanadium battery, energy is stored in the vanadium electrolyte. The electrolyte is the main component of the all-vanadium flow battery, which is composed of vanadium ions and sulfuric acid or hydrochloric acid. The positive electrode is composed of VO 2+ / VO2 + redox couple, and the negative electrode is composed of V 3+ / V 2+ redox couple. The electric pile is the place where the electrolyte is charged and discharged, and the electrolyte is transported by pump and pipeline to circulate between the storage tank and the electric pile. The initial valence state of vanadium ions in the electrolyte is 3:4, and the 1:1 electrolyte is 3.5 valence electrolyte.

[0004] However, with the long-term use of the vanadium battery system, the storage tank, pipeline, pump, electric pile material and the like will be continuously aged, and impurity ions will continuously enter the vanadium electrolyte, causing the vanadium electrolyte to be unusable, forming waste liquid; in addition, during the operation of the vanadium battery system, pipe breakage, battery stack leakage and the like may occur, causing a large amount of electrolyte to leak, the leaked electrolyte to contact the ground and introduce a large amount of impurities, which cannot be used continuously, thereby forming a large amount of waste liquid.

[0005] At present, there are mainly two ways to treat vanadium electrolyte waste liquid:

[0006] One is to carry out a series of vanadium precipitation operations on the failed electrolyte, and finally obtain vanadium compounds such as vanadium pentoxide, vanadyl sulfate and ammonium metavanadate. However, although the above method can obtain vanadium compounds, the purity of the obtained products is not high, and the products cannot be directly used as raw materials for vanadium electrolyte. Purification and impurity removal are required before the products can be used as raw materials for vanadium battery electrolyte. In addition, using vanadium compounds as raw materials to produce electrolyte requires additional electrolyte production processes, and the environmental protection cost and manufacturing cost are high.

[0007] Secondly, the invalid electrolyte is regenerated and then continuously used in the vanadium battery system, so as to prolong the service life of the electrolyte and reduce the cost of vanadium precipitation and electrolyte manufacturing. It is a relatively optimal choice in the disposal of vanadium waste liquid. Chinese patent document CN116914171A discloses a regeneration and utilization method of invalid electrolyte. The patent preliminarily processes the invalid electrolyte through pickling, ion exchange, membrane filtration and the like, then uses electron beam irradiation treatment to eliminate organic impurities, and finally filters and purifies again with an adsorbent to achieve the purpose of eliminating impurities in the invalid electrolyte and realizing electrolyte regeneration. This method has complicated steps, generates a large amount of wastewater, and the electron beam irradiation is harmful to the human body. Therefore, this method is not suitable for large-scale use. Chinese patent document CN102468499A discloses a regeneration method of waste liquid of all-vanadium redox flow battery. The patent contacts the positive electrolyte after the first charging of the all-vanadium redox flow battery with reducing agents such as oxalic acid, formic acid and tartaric acid to reduce the 5-valence vanadium ions in the electrolyte to 4-valence. The obtained 4-valence vanadium ion electrolyte is used as the positive or negative electrolyte of the vanadium battery. However, this method does not consider the influence of impurities. The 4-valence vanadium ion electrolyte obtained by reduction of waste liquid with high impurity content cannot be directly used as the electrolyte of the vanadium battery, otherwise it will greatly affect the performance and service life of the vanadium battery. Chinese patent document CN111509247A discloses a regeneration method of invalid vanadium battery electrolyte. The invalid positive and negative electrolytes of the vanadium battery are mixed, vanadium compounds, supporting electrolyte and water are added, and after solid-liquid separation, the liquid phase is sequentially subjected to capacitive deionization and electrolytic reduction in an electrolytic cell to obtain 3.5-valence vanadium electrolyte. However, the manufacturing process of the anode composite electrode and the cathode composite electrode involved in this method is complicated, especially for waste liquid with high impurity content, the composite electrode consumption is large, and the regeneration cost of the invalid electrolyte is high.

[0008] Therefore, it is necessary to design a regeneration method of vanadium electrolyte waste liquid, which can effectively treat high content of impurities and realize the regeneration of invalid electrolyte, so that the invalid electrolyte can be continuously used in the vanadium battery system, and the defects of the prior art method, such as complexity and high cost, are solved. SUMMARY

[0009] The present application provides a regeneration method of vanadium electrolyte waste liquid, which solves the problem that the prior art cannot effectively treat high content of impurities and realize the regeneration of invalid electrolyte, so that the invalid electrolyte can be continuously used in the vanadium battery system, and the defects of the prior art method, such as complexity and high cost, are solved.

[0010] The technical scheme of the present application is as follows:

[0011] In a first aspect, the present application provides a regeneration method of vanadium electrolyte waste liquid, comprising the following steps:

[0012] S1. Filtering the waste liquid for the first time to remove insoluble impurities;

[0013] S2. The filtered waste liquid is subjected to a first electrolytic reduction to reduce the valence of vanadium ions to below 3;

[0014] S3. An excess of flocculating agent is added to the waste liquid obtained in step S2 under stirring, and after sufficient reaction, a second filtration is performed to remove the flocculation product; the flocculating agent includes a copper flocculating agent and an amide polymer flocculating agent;

[0015] S4. The mother liquor obtained after the second filtration in step S3 is subjected to a second electrolytic reduction to deposit and remove copper;

[0016] S5. The electrolyte obtained after the treatment in step S4 is subjected to a vanadium ion valence adjustment to obtain a regenerated vanadium electrolyte.

[0017] Further, the first electrolytic reduction process is to place the waste liquid in the cathode of an electrolytic cell for electrolysis, and the anode is an aqueous solution of the same acid concentration, and the reduction reaction is adjusted by placing the waste liquid in the cathode of the electrolytic cell to reduce the valence of vanadium ions to 3 and below.

[0018] Further, the second electrolytic reduction process is to place the mother liquor in the cathode storage tank, and the mother liquor is circulated between the cathode storage tank and the cathode chamber of the electrolytic cell, and a solution of the same acid concentration as the mother liquor is circulated between the anode storage tank and the anode chamber of the electrolytic cell.

[0019] Further, the vanadium ion valence adjustment process is to place the electrolyte in the anode of an electrolytic cell for electrolysis, and the cathode is an aqueous solution of the same acid concentration.

[0020] Further, the copper flocculating agent includes at least one of copper sulfate and copper hydroxide; the amide polymer flocculating agent includes at least one of polyacrylamide and polyvinylamide; the amide polymer flocculating agent is preferably cationic polyacrylamide.

[0021] Further, the amide polymer flocculating agent is cationic polyacrylamide, and when the copper flocculating agent is copper sulfate, the mass ratio of copper sulfate to cationic polyacrylamide is greater than 2.5:1; and when the copper flocculating agent is copper hydroxide, the mass ratio of copper hydroxide to cationic polyacrylamide is greater than 1.5:1.

[0022] Further, the first filtration is used to remove insoluble impurities, and at least one of a screen filter, a laminated filter, a sand rod filter, a carbon filter, a plate and frame filter, and an activated carbon filter is used; and / or, the second filtration is used to remove agglomerated gelatinous flocculation containing a large amount of impurity ions, and at least one of a screen filter, a laminated filter, a sand rod filter, a carbon filter, a plate and frame filter, and an activated carbon filter is used.

[0023] Further, the vanadium electrolyte waste liquid has a vanadium concentration of 1-4.0 mol / L, and the vanadium includes a sum of vanadium ions in any valence state.

[0024] The second object of the present application is to provide an application of the regeneration method of the first aspect to preparation of a vanadium electrolyte.

[0025] Further, the vanadium electrolyte has a vanadium ion valence state of 3.5 valence, which meets the initial valence state of vanadium ions of the electrolyte.

[0026] Compared with the prior art, the present application has at least the following beneficial effects:

[0027] The regeneration method of the vanadium electrolyte waste liquid of the present application uses vanadium battery waste liquid as raw material, filters out insoluble impurities in the waste liquid through first filtration, adjusts the valence state of the electrolyte to be lower than 3+ through first electrolysis to avoid flocculation of vanadium ions due to high valence state; a flocculating agent is added for stirring to cause flocculation reaction, and after flocculation of impurity ions, second filtration is performed; the filtered vanadium electrolyte is subjected to second electrolysis through an electrolysis device, copper ions are deposited on the cathode electrode, and through the flushing of the electrolyte, the deposited copper is brought into the cathode liquid tank and settled, so that the copper ions introduced by the flocculating agent are removed, and the electrolyte is adjusted to the target valence state, and finally a regenerated high-purity vanadium electrolyte is obtained; the whole method is simple in operation, low in energy consumption, pollution-free, high in efficiency and short in regeneration time. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0029] Figure 1 The present application provides a vanadium electrolyte waste liquid regeneration method. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described in detail below with reference to the embodiments of the present application. Obviously, the described embodiments only represent some embodiments of the present application, but not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] REFERENCE Figure 1In one embodiment, a method for regenerating vanadium electrolyte waste solution is provided, comprising the following steps:

[0032] S1. First filtration of the waste solution to remove insoluble impurities;

[0033] S2. First electrolytic reduction of the filtered waste solution until the valence of vanadium ions is reduced to less than 3;

[0034] S3. Adding an excess of flocculating agent to the waste solution obtained in step S2 under stirring, and after sufficient reaction, performing second filtration to remove the flocculation product; the flocculating agent includes copper flocculating agent and amide polymer flocculating agent;

[0035] S4. Second electrolytic reduction of the mother liquor after the filtration in step S3 to deposit and remove copper;

[0036] S5. Adjusting the valence of vanadium ions of the electrolyte after step S4 to obtain regenerated vanadium electrolyte.

[0037] In the above embodiment, the regeneration method first filters the waste solution to remove insoluble impurities, adjusts the valence of the electrolyte to less than 3 through first electrolysis, avoids flocculation due to high valence of vanadium ions, adds a flocculating agent for stirring and flocculation reaction, performs second filtration after flocculation of impurity ions, performs second electrolysis of the filtered vanadium electrolyte by an electrolysis device, copper ions are deposited on the cathode electrode, and the deposited copper is brought into the cathode storage tank and settled through the flushing of the electrolyte, thereby removing the copper ions introduced by the flocculating agent, and the electrolyte is adjusted to the target valence to finally obtain regenerated high-purity vanadium electrolyte. The entire method is simple to operate, low in energy consumption, pollution-free, high in efficiency, and short in regeneration time.

[0038] In a preferred embodiment, the copper flocculating agent can be at least one of copper sulfate and copper hydroxide; the amide polymer flocculating agent includes at least one of polyacrylamide and polyvinylamide, and preferably cationic polyacrylamide. By using a mixture of copper hydroxide or copper sulfate and amide high molecular organic polymer such as polyacrylamide and polyvinylamide as the flocculating agent, common impurity ions such as iron, calcium, silicon, aluminum, and chromium in the trivalent vanadium electrolyte waste solution are removed. The excess copper ions in the filtrate are deposited on the cathode electrode through electrolysis and are flushed into the cathode storage tank through the flow of the electrolyte between the cathode storage tank and the cathode chamber. Since the density of elemental copper is much greater than that of the electrolyte, elemental copper is deposited at the bottom of the cathode storage tank, thereby achieving the purpose of removing copper ions from the electrolyte and regenerating the vanadium electrolyte waste solution. The flocculating agent used is simple to obtain, inexpensive, and easy to operate, and through flocculation and electrodeposition, impurity ions in the waste solution can be effectively removed.

[0039] In the above embodiments, the adjustment of valence state and flocculation precipitation and copper deposition mainly consider the synergy of the following effects: the copper ion in the flocculant copper hydroxide or copper sulfate can generate macromolecular complex with PAM under acidic conditions, and the complex can have flocculation and chelation effects with various ions such as calcium ions, silicon ions, iron ions, aluminum ions, and chromium ions, thereby generating colloidal precipitate. The complex does not have chelation effect with divalent and trivalent vanadium ions, but only has flocculation and chelation effects with tetravalent and pentavalent vanadium ions. Thus, the valence state of the vanadium electrolyte waste liquid can be adjusted to trivalent or below, and then the macromolecular complex generated by the copper ion in the copper hydroxide or copper sulfate and PAM is flocculated to remove impurity ions other than copper ions. The excess copper ions are removed by electrolytic deposition, thereby achieving the effect of removing impurity ions in the trivalent vanadium electrolyte.

[0040] In preferred embodiments, to ensure that the added amide polymer flocculant can be subsequently removed in the production of the product by flocculation and chelation, the copper flocculant is in excess relative to the amide polymer flocculant when added, i.e. an excess of copper flocculant is added first to allow the amide polymer flocculant to flocculate sufficiently to generate macromolecular complexes. Specifically, if cationic polyacrylamide (CPAM) is selected, and copper sulfate is selected as the copper flocculant, the mass ratio of copper sulfate to CPAM is greater than 2.5:1; if copper hydroxide is selected as the copper flocculant, the mass ratio of copper hydroxide to CPAM is greater than 1.5:1.

[0041] In preferred embodiments, the amount of flocculant used is preferably excessive, i.e. the flocculant is continuously added during the stirring and flocculation process until the content of free metal impurity ions in the electrolyte waste liquid no longer decreases. This process can be achieved with the aid of detection means. Considering the content of metal impurity ions in general waste liquid, the amount of flocculant added can be considered to be 0.1-1% of the mass of the waste liquid. For example, if the electrolyte has been used for a long time and has introduced impurities, the content of impurities is low, and the amount of flocculant added is 0.1-0.5%; if the impurities introduced are mainly from leaks on the ground, the amount of flocculant added is 0.5-1%.

[0042] In the preferred embodiment, the electrolysis process occurs at the anode oxidation reaction, and the cathode occurs reduction reaction, the person skilled in the art can be adapted to the selection of the appropriate electrolysis required units and reagents according to the reaction principle and the desired reduction / oxidation effect. As is well known in the art, the electrolysis device includes electrolytic tank, anode storage tank, cathode storage tank, anode circulating pump, cathode circulating pump, DC power supply. The electrolytic tank includes anode plate, anode electrode, cathode plate, cathode electrode, anode chamber, cathode chamber, diaphragm; the electrolytic tank anode plate is one of lead plate, titanium plate, stainless steel or graphite plate; the electrolytic tank anode electrode is one of titanium felt, nickel felt, graphite felt, stainless steel fiber felt; the electrolytic tank cathode plate is one of lead plate, DSA, graphite plate; the electrolytic tank anode electrode is one of titanium felt, nickel felt, graphite felt, stainless steel fiber felt; the electrolytic tank diaphragm is one of cation exchange membrane, proton exchange membrane, anion exchange membrane, PBI membrane.

[0043] In the above embodiment, the vanadium electrolyte waste liquid can come from the tank, pipeline, pump, battery material and other will continue to age, impurity ions introduced to form the vanadium electrolyte can not be used to form the waste liquid; also can come from the vanadium battery system running process pipeline breakage, battery leakage caused by electrolyte leakage, and ground contact to introduce a large number of impurities to form a large amount of waste liquid. The waste liquid includes but is not limited to one or more of the following impurities: calcium ions, silicon ions, iron ions, aluminum ions and chromium ions; the silicon ion exists in the form of one or more of the following: water soluble silicon, amorphous silicon, colloidal silicon. The sum of the concentration of vanadium ions in any state in the vanadium electrolyte waste liquid is not limited to a certain concentration. In actual vanadium battery electrolyte, the vanadium concentration is usually 1-4.0 mol / L; the impurity ions include the electrolyte waste liquid regeneration of the above-mentioned combined impurity ions. After regeneration, the impurity ion concentration is significantly reduced.

[0044] The following is a preferred embodiment of the present application. The electrolyte waste liquid is a vanadium electrolyte waste liquid leaked to the ground. 1 m 3 The total vanadium molar number of the electrolyte waste liquid is 2.0 x 10 3 mol.

[0045] Unless otherwise specified, the reagents used are commercially available standard products, and the experimental operation processes involved are basic operations well known and mastered by those skilled in the art.

[0046] Example 1

[0047] The regeneration process is as follows: first filtration is performed using a 1000 mesh screen filter to filter out insoluble impurities, the waste liquid is placed in the cathode of the electrolytic cell, electrolysis is performed, vanadium ions are electrolyzed to 3 valence, 3.0 kg of copper hydroxide mixed with 2.0 kg of cationic polyacrylamide powder is added, stirring for 30 minutes, fully flocculating, second filtration is performed using a 3000 mesh screen filter, the filtered vanadium liquid is placed in the cathode storage tank of the electrolytic device, transported by the cathode circulating pump, the vanadium liquid circulates between the cathode storage tank and the cathode chamber of the electrolytic cell, and the same sulfate aqueous solution circulates between the anode storage tank and the anode chamber of the electrolytic cell through the anode circulating pump. The anode plate of the electrolytic cell is a lead plate, the anode electrode of the electrolytic cell is a titanium felt, the cathode plate of the electrolytic cell is a graphite plate, the cathode electrode of the electrolytic cell is a graphite felt, the cathode and anode of the electrolytic cell are connected with the negative and positive poles of the direct current power supply respectively, and the electrolytic cell is electrolyzed by 100 A direct current. After 30 minutes, the electrolysis is stopped, the elemental copper obtained by electrodeposition is accumulated at the bottom of the cathode storage tank, and the electrolyte is taken for impurity ion detection. The electrolyte is placed in the anode of the electrolytic cell, electrolysis is performed, the valence of vanadium ions is adjusted to 3.5 valence, and the total vanadium recovery rate is greater than 99.99%.

[0048] Example 2

[0049] The regeneration process is as follows: first filtration is performed using a 1000 mesh screen filter to filter out insoluble impurities, the waste liquid is placed in the cathode of the electrolytic cell, electrolysis is performed, vanadium ions are electrolyzed to 3 valence, 3.6 kg of copper sulfate mixed with 1.4 kg of cationic polyacrylamide powder is added, stirring for 30 minutes, fully flocculating, second filtration is performed using a 3000 mesh screen filter, the filtered vanadium liquid is placed in the cathode storage tank of the electrolytic device, transported by the cathode circulating pump, the vanadium liquid circulates between the cathode storage tank and the cathode chamber of the electrolytic cell, and the same sulfate aqueous solution circulates between the anode storage tank and the anode chamber of the electrolytic cell through the anode circulating pump. The anode plate of the electrolytic cell is a lead plate, the anode electrode of the electrolytic cell is a titanium felt, the cathode plate of the electrolytic cell is a graphite plate, the cathode electrode of the electrolytic cell is a graphite felt, the cathode and anode of the electrolytic cell are connected with the negative and positive poles of the direct current power supply respectively, and the electrolytic cell is electrolyzed by 100 A direct current. After 30 minutes, the electrolysis is stopped, the elemental copper obtained by electrodeposition is accumulated at the bottom of the cathode storage tank, and the electrolyte is taken for impurity ion detection. The electrolyte is placed in the anode of the electrolytic cell, electrolysis is performed, the valence of vanadium ions is adjusted to 3.5 valence, and the total vanadium recovery rate is greater than 99.99%.

[0050] Example 3

[0051] The regeneration process is as follows: first filtration is performed using a 1000-mesh screen filter to remove insoluble impurities, the waste liquid is placed in the cathode of an electrolytic cell, electrolysis is performed, vanadium ions are electrolyzed to the 3+ state, 1.5 kg of copper hydroxide, 2.0 kg of copper sulfate and 1.5 kg of a mixed powder of cationic polyacrylamide are added, stirring is performed for 30 minutes, complete flocculation is achieved, second filtration is performed using a 3000-mesh screen filter, the filtered vanadium liquid is placed in the cathode storage tank of the electrolytic device, is transported by the cathode circulating pump, and circulates between the cathode storage tank and the cathode chamber of the electrolytic cell; an aqueous sulfuric acid solution with the same sulfate radical circulates between the anode storage tank and the anode chamber of the electrolytic cell by the anode circulating pump. The anode plate of the electrolytic cell is a lead plate, the anode electrode of the electrolytic cell is a titanium felt, the cathode plate of the electrolytic cell is a graphite plate, the cathode electrode of the electrolytic cell is a graphite felt, the cathode and the anode of the electrolytic cell are connected to the negative and positive poles of a direct current power supply, respectively, and the electrolytic cell is electrolyzed by 100 A direct current. After 30 minutes, the electrolysis is stopped, the elemental copper obtained by electrodeposition is accumulated at the bottom of the cathode storage tank, and the electrolyte is taken for impurity ion detection. The electrolyte is placed in the anode of the electrolytic cell, electrolysis is performed, the valence state of the vanadium ions is adjusted to 3.5, and the total vanadium recovery rate is greater than 99.99%.

[0052] Comparative Example 1

[0053] The steps and methods used in this example are basically the same as in Example 1, except that no copper hydroxide is added to the flocculant.

[0054] Comparative Example 2

[0055] The steps and methods used in this example are basically the same as in Example 1, except that no polyacrylamide is added to the flocculant.

[0056] Comparative Example 3

[0057] The steps and methods used in this example are basically the same as in Example 1, except that no adjustment of the valence state of the vanadium ions is performed before adding the flocculant.

[0058] In the above examples and Comparative Examples 1-3, the comparison results of the impurity ions in the vanadium electrolyte waste liquid before treatment and after treatment are shown in Table 1. As can be seen from the comparison of the ICP data shown in Table 1, this method can effectively remove the impurity ions in the vanadium waste liquid, the treated electrolyte meets the requirements for continued use of the vanadium battery, and the vanadium recovery rate in the electrolyte regeneration process is high.

[0059] Table 1: Comparison of impurity ions in vanadium electrolyte waste liquid before and after treatment

[0060]

[0061] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for regenerating vanadium electrolyte spent solution, characterized by the steps of The method comprises the following steps: S1. First filtration of the waste liquid to remove insoluble impurities; S2. First electrolytic reduction of the filtered waste liquid until the valence of vanadium ions is reduced to less than 3; S3. Adding an excess of flocculant to the waste liquid obtained in step S2 under stirring, and then performing second filtration to remove the flocculation product after sufficient reaction; the flocculant comprises a copper flocculant and an amide polymer flocculant; S4. Second electrolytic reduction of the mother liquor filtered in step S3 to deposit and remove copper; S5. Adjusting the valence of vanadium ions in the electrolyte treated in step S4 to obtain regenerated vanadium electrolyte.

2. The regeneration method according to claim 1, characterized by, The first electrolytic reduction process is to place the waste liquid in the cathode of an electrolytic cell for electrolysis, and the anode is an aqueous solution of the same acid concentration.

3. The reproducing method according to claim 1, wherein The second electrolytic reduction process is to place the mother liquor in the cathode storage tank, and the mother liquor is circulated between the cathode storage tank and the cathode chamber of the electrolytic cell, and a solution of the same acid concentration as the mother liquor is circulated between the anode storage tank and the anode chamber of the electrolytic cell.

4. The reproducing method according to claim 1, wherein The vanadium ion valence adjustment process is to place the electrolyte in the anode of an electrolytic cell for electrolysis, and the cathode is an aqueous solution of the same acid concentration.

5. The regeneration method of claim 1, wherein, The copper flocculant comprises at least one of copper sulfate and copper hydroxide; and the amide polymer flocculant comprises at least one of polyacrylamide and polyvinylamide.

6. The reproduction method according to claim 5, wherein When the copper flocculant is copper sulfate, the mass ratio of copper sulfate to cationic polyacrylamide is greater than 2.5:1; and when the copper flocculant is copper hydroxide, the mass ratio of copper hydroxide to cationic polyacrylamide is greater than 1.5:

1.

7. The regeneration method of claim 1, wherein, The vanadium concentration in the vanadium electrolyte waste liquid is 1-4.0 mol / L.

8. The regeneration method of claim 1, wherein, The vanadium electrolyte waste liquid comprises one or more impurities of calcium ions, silicon ions, iron ions, aluminum ions and chromium ions.

9. Use of the regeneration method of any one of claims 1-8 in the preparation of a vanadium electrolyte.

10. Use according to claim 9, wherein The valence of vanadium ions in the vanadium electrolyte is 3.5.

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