Impurity purification method for lead electrolysis anode slime washing water

Abstract

The invention discloses an impurity purification method for lead electrolysis anode slime washing water, which comprises the following steps: 1) primary purification: stirring the lead electrolysis anode slime washing water, adding a phosphoric acid solution while stirring, and continuously stirring after the phosphoric acid solution is added to obtain a primary purified mixed solution; 2) primary slag-liquid separation: separating a solution and a precipitate in the primary purified mixed solution to obtain a primary purified solution and primary purified slag; (3) secondary purification: stirring the primary purification liquid, adding a hydrobromic acid solution into the primary purification liquid while stirring, and continuously stirring after adding to obtain a secondary purification mixed liquid; and 4) secondary slag-liquid separation: separating the solution and the precipitate in the secondary purified mixed solution to obtain a secondary purified solution and secondary purified slag. According to the method, impurity metal in the lead electrolysis anode slime washing water can be effectively removed, the content of impurities in lead separated out when the washing water is recycled to a lead electrolysis solution system is greatly reduced, and resource utilization of purification residues is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of lead electrolysis refining, and in particular to a method for purifying impurities in lead electrolysis anode mud washing water. Background Art

[0002] In the process of lead smelting, lead ore is often smelted to produce crude lead with a lead content of 93% to 98%, and then the crude lead is electrolytically refined to make the lead content reach about 99.99%. In the process of electrolytic refining of crude lead, the lead in the anode gradually dissolves into the solution and deposits at the cathode, while the valuable metals such as Au, Ag, Sb, Bi in the crude lead mainly exist in the form of anode mud.

[0003] In order to recover valuable metals and acid lead resources in anode mud, anode mud is often washed and filtered by adding water to obtain anode mud and anode mud washing water, and then the anode mud is directly sent to the rare and precious metal recovery system to recover valuable metals. Anode mud washing water often directly enters the crude lead electrolysis system for recycling. The anode mud washing water has a high content of impurity metals such as Zn, Fe, Cu, Ag, Sn, and Bi, which is a high-enrichment area of ​​the lead electrolysis system solution. If it directly enters the crude lead electrolysis system without purification, it is easy to cause impurities in the precipitated lead to exceed the standard.

[0004] At present, there are studies in the prior art to solve the problem of impurity purification in lead electrolysis anode mud washing water. For example, patent application number CN201810846031.7 discloses a lead anode mud washing water impurity removal process, which mainly uses 200 mesh lead powder to add lead anode mud washing water under normal temperature and pressure conditions, and puts it into the purification tank for mechanical stirring for 6 hours. The bismuth replacement rate can reach 96.99% and the antimony replacement rate can reach 76.69%. The purpose of purification and impurity removal is basically achieved by filtering the anode mud water after replacement, and the lead ions in the lead anode mud can be relatively completely returned to the electrolyte circulation system, making the electrolyte composition relatively stable.

[0005] The impurity removal process is to use lead powder and Bi 3+ and Sb 3+ Bismuth and antimony are removed by substitution reaction. However, the anode mud washing water does not only contain impurity metals Bi and Sb, but also contains impurity metals such as Cu, Ag, Sn, Zn, Fe, Cd, and Ni. These impurity metals will still cause the anode mud washing water to be enriched in the lead electrolysis system solution when it is recycled to the lead electrolysis system, and enter into the lead precipitated by electrolysis, causing the impurities in the lead to exceed the standard, further causing the total amount of impurities in the lead to seriously exceed the standard, greatly reducing the quality of refined lead. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for purifying impurities in lead electrolysis anode mud washing water, which can effectively remove impurity metals in lead electrolysis anode mud washing water and greatly reduce the content of impurities in the lead precipitated when the washing water is recycled into the lead electrolysis solution system.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for purifying impurities in lead electrolysis anode mud washing water, comprising the following steps:

[0008] 1) Primary purification: stirring the lead electrolysis anode mud washing water, adding the phosphoric acid solution while stirring, and continuing to stir after the addition is completed, so as to purify the impurities in the lead electrolysis anode mud washing water to obtain a primary purified mixed solution;

[0009] 2) Primary slag-liquid separation: separating the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag;

[0010] 3) Secondary purification: stirring the primary purified liquid, while adding the hydrobromic acid solution to the primary purified liquid while stirring, and continuing to stir after the addition is completed to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid;

[0011] 4) Secondary slag-liquid separation: the solution and the precipitate in the secondary purification mixed liquid are separated to obtain secondary purification liquid and secondary purification slag.

[0012] In the present invention, when purifying electrolytic anode mud washing water, phosphoric acid solution is first used to purify the anode mud washing water, so that the Zn 2+ , Fe 2+ 、Cd 2+ 、Ni 2+ Sn 2+ 、Bi 3+ , Cu 2+ 、Ag + It reacts with phosphoric acid solution to form insoluble or slightly soluble salts that precipitate from the solution. The chemical reactions that occur in one purification step are:

[0013] 3Zn 2+ +2PO4 3- =Zn3(PO4)2↓

[0014] 3Fe 2+ +2PO4 3- =Zn3(PO4)2↓

[0015] 3C 2+ +2PO4 3- =Cd3(PO4)2↓

[0016] 3Ni 2+ +2PO43- =Ni3(PO4)2↓

[0017] 3Sn 2+ +2PO4 3- =Sn3(PO4)2↓

[0018] Bi 3+ +PO4 3- =BiPO4↓

[0019] 3Cu 2+ +2PO4 3- =Cu3(PO4)2↓

[0020] 3Ag + +PO4 3- =Ag3PO4↓

[0021] Then, a physical method (such as standing, filtering, filter pressing, etc.) is used to separate the solution and the precipitate in the first purification mixed liquid obtained by the first purification to obtain a first purification liquid and a first purification residue;

[0022] The inventors found in practice that the Cd in the primary purified liquid obtained after being treated with phosphoric acid solution 2+ 、Bi 3+ 、Ag + and Sb 3+ The content of impurity metals will still cause the impurity content of lead in the subsequent lead electrolysis to exceed the standard. In order to further reduce the impurities in the washing water, after multiple experiments, it was found that hydrobromic acid can effectively remove the impurity metals in the primary purification liquid. Therefore, after the primary purification treatment, the primary purification liquid is further purified by hydrobromic acid solution to reduce the Cd in the primary purification liquid. 2+ 、Bi 3+ 、Ag + and Sb 3+ Reacts with hydrobromic acid to form insoluble or slightly soluble salts which precipitate from the solution. The chemical reactions that occur in the secondary purification step are:

[0023] Cd 2+ +2Br - =CdBr2↓

[0024] Sb 3+ +3Br - =CdBr3↓

[0025] Bi 3+ +3Br - =BiBr3↓

[0026] Ag + +Br - =AgBr↓

[0027] The content of impurity metals in the wash water (i.e., the secondary purified liquid) obtained after two purification treatments can be effectively reduced, so that the content of the wash water when it is returned to the lead electrolysis solution is less, which greatly reduces the content of impurity metals precipitated with the lead during electrolysis in the lead electrolysis system, reduces the content of impurity metals in the precipitated lead, and further reduces the total amount of impurities in the lead, so that the refined lead obtained meets the standards.

[0028] Furthermore, the primary purified slag obtained in step 2) is sent to a rare metal recovery system or a lead smelting raw material system for valuable metal recovery.

[0029] Furthermore, the secondary purified slag obtained in step 4) is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery, and the secondary purified liquid is sent to a lead electrolytic solution system for recycling.

[0030] Furthermore, in the step 1), the concentration of the phosphoric acid solution is 50 to 150 g / L, the volume ratio of the phosphoric acid solution to the lead electrolysis anode mud washing water is 1:(10 to 30), the phosphoric acid solution is added at a rate of 0.1 to 0.2 L / min, and the stirring time after adding the phosphoric acid solution is continued for 0.5 to 10 min, and the stirring speed is 300 to 400 rpm.

[0031] Furthermore, in the step 2), any one of standing, filtering or filter pressing is used to separate the solution and the precipitate in the primary purified mixed solution.

[0032] Furthermore, the standing time is 1 to 48 hours.

[0033] Furthermore, in the step 3), the concentration of the hydrobromic acid solution is 50 to 150 g / L, the volume ratio of the hydrobromic acid solution to the primary purification liquid is 1:(10 to 30), the addition rate of the hydrobromic acid solution is 0.1 to 0.2 L / min, and the stirring time after adding the hydrobromic acid solution is 0.5 to 10 min, and the stirring speed is 300 to 400 rpm.

[0034] Furthermore, in the step 4), any one of standing, filtering or filter pressing is used to separate the solution and the precipitate in the secondary purified mixed solution.

[0035] Furthermore, the standing time is 1 to 48 hours.

[0036] Beneficial effects of the impurity purification method of lead electrolysis anode mud washing water of the present invention:

[0037] (1) The method of the present invention is simple. To solve the problem of impurity metals in the anode mud washing water of lead electrolysis, phosphoric acid solution is first used to purify the anode mud washing water, thereby achieving a primary purification of Zn, Fe, Cd, Ni, Sn, Bi, Cu, and Ag impurities in the anode mud washing water of lead electrolysis. Then, hydrobromic acid solution is used to purify the primary purified liquid obtained by the primary purification treatment for a secondary time, so that Cd, Bi, and Ag that are not completely purified in the primary purification treatment are further purified, and at the same time, the unpurified Sb is preliminarily purified and removed. Under the common use of phosphoric acid and hydrobromic acid, the impurity metals (Zn, Fe, Cd, Ni, Sn, Bi, Cu, Ag, and Sb) in the anode mud washing water can be effectively removed, so that when the washing water after the purification treatment of the present invention is recycled into the lead electrolysis solution for recycling, the content of these impurity metals in the lead electrolysis solution is reduced, and the phenomenon of impurity metals being precipitated together with lead in the lead electrolysis process can be effectively reduced, thereby greatly reducing the content of each impurity metal in the precipitated lead and the total amount of impurities, so that the precipitated lead meets the standard requirements and improves the quality of refined lead;

[0038] (2) The primary purification slag and secondary purification slag obtained in the primary purification and secondary purification processes of the present invention are sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery, and the secondary purification liquid is sent to a lead electrolytic solution system for recycling. The slag and purification liquid generated in the entire purification process can be recycled without introducing new impurities. The entire process does not generate waste gas, waste slag, waste water and other wastes, thereby realizing the resource utilization of anode mud washing water and purification slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 — is a process flow chart of a method for purifying impurities in lead electrolysis anode mud washing water according to the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with the accompanying drawings and examples, but these specific implementation schemes do not limit the protection scope of the present invention in any way.

[0041] In order to compare the impurity removal effect of the present invention, the following examples and comparative examples all use the lead electrolysis anode mud washing water shown in Table 1 for purification and related detection experiments.

[0042] Table 1 Impurity content in industrial lead electrolysis anode mud washing water

[0043]

[0044] The electrolytic anode mud washing water shown in Table 1 is sent to the lead electrolysis solution system for lead electrolysis test, and the content of impurity metals in the precipitated lead when the anode mud washing water without impurity removal is recycled to the lead electrolysis system is determined. The specific operation method is as follows:

[0045] Take 30L of lead electrolysis anode mud washing water shown in Table 1 and add it at a current density of 150A / m 2 The lead electrolysis test was carried out for 36 hours under the condition of an electrolyte circulation rate of 160 ml / min, and the content of each impurity metal in the precipitated lead obtained by electrolysis was tested. The test results are shown in Table 2.

[0046] Table 2 Lead impurity content of anode mud washing water without impurity removal treatment (×10 -4 / % )

[0047]

[0048] 30L at a current density of 150A / m 2 , a lead electrolysis test was carried out for 36 hours under the condition of an electrolyte circulation rate of 160 ml / min, and the precipitated lead obtained by electrolysis was tested. The test results are shown in Table 2.

[0049] Example 1

[0050] A method for purifying impurities in lead electrolysis anode mud washing water, the process flow chart of which is as follows Figure 1 As shown, the following steps are included:

[0051] 1) Primary purification: 30 L of the lead electrolysis anode mud washing water shown in Table 1 was stirred at 300 rpm, and then 1.5 L of a 100 g / L phosphoric acid solution was added at a rate of 0.2 L / min while stirring. After the addition was completed, stirring was continued for 5 min to purify the impurities in the lead electrolysis anode mud washing water to obtain a primary purified mixed solution;

[0052] 2) Primary slag-liquid separation: The primary purified mixed liquid is filtered by filtering to separate the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag; the primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery;

[0053] 3) Secondary purification: Stir the primary purified liquid at 300 rpm, and add 1.5 L of 100 g / L hydrobromic acid solution to the primary purified liquid at a rate of 0.2 L / min while stirring. After the addition is completed, continue stirring for 5 min to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid;

[0054] 4) Secondary slag-liquid separation: The secondary purified mixed liquid is filtered by filtering method to separate the solution and precipitate in the secondary purified mixed liquid to obtain secondary purified liquid and secondary purified slag. The primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to the lead electrolytic solution system for recycling.

[0055] Example 2

[0056] A method for purifying impurities in lead electrolysis anode mud washing water comprises the following steps:

[0057] 1) Primary purification: 30 L of the lead electrolysis anode mud washing water shown in Table 1 was stirred at 400 rpm, and then 1 L of a phosphoric acid solution with a concentration of 150 g / L was added at a rate of 0.1 L / min while stirring. After the addition was completed, stirring was continued for 5 min to purify the impurities in the lead electrolysis anode mud washing water to obtain a primary purified mixed solution;

[0058] 2) Primary slag-liquid separation: The primary purified mixed liquid is filtered by filtering to separate the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag; the primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery;

[0059] 3) Secondary purification: Stir the primary purified liquid at 350 rpm, and add 1 L of 100 g / L hydrobromic acid solution to the primary purified liquid at a rate of 0.15 L / min while stirring. After the addition is completed, continue stirring for 5 min to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid;

[0060] 4) Secondary slag-liquid separation: The secondary purified mixed liquid is filtered by filtering method to separate the solution and precipitate in the secondary purified mixed liquid to obtain secondary purified liquid and secondary purified slag. The primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to the lead electrolytic solution system for recycling.

[0061] Example 3

[0062] A method for purifying impurities in lead electrolysis anode mud washing water comprises the following steps:

[0063] 1) Primary purification: 30 L of the lead electrolysis anode mud washing water shown in Table 1 was stirred at 350 rpm, and then 3 L of a 50 g / L phosphoric acid solution was added at a rate of 0.15 L / min while stirring. After the addition was completed, stirring was continued for 5 min to purify the impurities in the lead electrolysis anode mud washing water to obtain a primary purified mixed solution;

[0064] 2) Primary slag-liquid separation: The primary purified mixed liquid is filtered by filtering to separate the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag; the primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery;

[0065] 3) Secondary purification: The primary purified liquid was stirred at 400 rpm, and 3 L of a 75 g / L hydrobromic acid solution was added to the primary purified liquid at a rate of 0.1 L / min while stirring. After the addition was completed, stirring was continued for 5 min to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid;

[0066] 4) Secondary slag-liquid separation: The secondary purified mixed liquid is filtered by filtering method to separate the solution and precipitate in the secondary purified mixed liquid to obtain secondary purified liquid and secondary purified slag. The primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to the lead electrolytic solution system for recycling.

[0067] The present invention measured the content of each impurity metal in the wash water (secondary purification liquid) after purification in Examples 1-3, and the results are shown in Table 3:

[0068] Table 3 Content of impurity metals in the purified wash water and the unpurified wash water of Example 1-3

[0069]

[0070] The present invention also sends the purified wash water (secondary purified liquid) of Examples 1-3 to a lead electrolysis solution system for a lead electrolysis test, and determines the content of impurities in the precipitated lead when the wash water is recycled to the lead electrolysis system. The specific operation method is as follows:

[0071] Take 30L of the purified water (secondary purified liquid) from Example 1-3 and run it at a current density of 150A / m 2 , a lead electrolysis test was carried out for 36 hours under the condition of an electrolyte circulation rate of 160 ml / min, and the precipitated lead obtained by electrolysis was tested. The test results are shown in Table 4.

[0072] Table 4 Lead impurity content of the purified washing water and the unpurified washing water in Example 1-3 (×10 -4 / % )

[0073]

[0074] It can be seen from Table 3 that compared with the unpurified lead electrolysis anode mud wash water (i.e., the unpurified wash water shown in Table 1), after the impurity removal and purification by the method of the present invention in Examples 1-3, the impurity metals Cu, Bi, Ag, As, Sb, Sn, Zn, Fe, Cd, and Ni in the wash water can be significantly reduced.

[0075] And it can be seen from Table 4 that when the washed water purified by Examples 1-3 is used and sent to the lead electrolytic solution for electrolysis, the content of each impurity metal in the precipitated lead is significantly reduced compared to sending the unpurified absorbed water to the lead electrolytic solution for electrolysis, and the total amount of impurities is reduced by at least 80.7%.

[0076] Combining Table 3 and Table 4, it is shown that the purification method of the present invention can effectively remove impurities in the lead electrolysis anode mud washing water, thereby greatly reducing the content of impurity metals returned to the lead electrolysis solution through the washing water, and further reducing the content of impurity metals precipitated with lead during the electrolysis process, thereby significantly reducing the content of various metal impurities in the precipitated lead, so that the impurities and the total amount of impurities in the precipitated lead do not exceed the standard, all meet the GB / T 469-2023Pb99.996 standard, and improve the quality of the precipitated lead.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that step 3) secondary purification and step 4) secondary slag-liquid separation are not included.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 1 is that: step 1) primary purification and step 2) primary slag-liquid separation are not included, and the lead electrolysis anode mud washing water is directly purified by hydrobromic acid solution, that is, step 3) secondary purification and step 4) secondary slag-liquid separation are directly carried out.

[0081] Comparative Example 3

[0082] The difference between this comparative example and Example 1 is that: hydrobromic acid solution is first used for purification and slag-liquid separation, and then phosphoric acid solution is used for purification and slag-liquid separation.

[0083] Comparative Example 4

[0084] The difference between this comparative example and Example 1 is that in step 3), silicofluoric acid is used for secondary purification.

[0085] Comparative Example 5

[0086] In this comparative example 1, lead powder is used to purify the anode mud washing water of lead electrolysis, and the specific operation method is as follows:

[0087] The fine lead powder with a mesh size of 150 or more is added to the lead electrolysis anode mud washing water at a liquid-to-solid ratio of 20:1, and then stirred for 5 minutes at a stirring speed of 300 rpm to obtain a purified mixed solution; then the solution and the precipitate in the purified mixed solution are separated by filtering to obtain purified slag and purified liquid; the purified slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery; and the purified liquid is sent to a lead electrolysis solution system for recycling.

[0088] Comparative Example 6

[0089] In this comparative example 1, lead powder is first used to purify the lead electrolysis anode mud washing water and separate the slag liquid, and then hydrobromic acid is used to purify the lead electrolysis anode mud washing water and separate the slag liquid. The specific operation method is:

[0090] 1) Primary purification: add lead powder with a mesh size of 150 or more into the lead electrolysis anode mud washing water at a liquid-solid ratio of 20:1, and then stir for 5 minutes at a stirring speed of 300 rpm to obtain a primary purified mixed solution;

[0091] 2) Primary slag-liquid separation: The primary purified mixed liquid is filtered by filtering to separate the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag; the primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery;

[0092] 3) Secondary purification: Stir the primary purified liquid at 300 rpm, and add 1.5 L of 100 g / L hydrobromic acid solution to the primary purified liquid at a rate of 0.2 L / min while stirring. After the addition is completed, continue stirring for 5 min to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid;

[0093] 4) Secondary slag-liquid separation: The secondary purified mixed liquid is filtered by filtering method to separate the solution and precipitate in the secondary purified mixed liquid to obtain secondary purified liquid and secondary purified slag. The primary purified slag is sent to the rare and precious metal recovery system or the lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to the lead electrolytic solution system for recycling.

[0094] In the present invention, the difference table of purification methods of Example 1 and Comparative Examples 1-6 is shown in the following table:

[0095] Table 5 Differences between purification methods of Example 1 and Comparative Examples 1-5

[0096] Purification methods Example 1 Phosphoric acid solution, slag-liquid separation, hydrobromic acid solution, slag-liquid separation Comparative Example 1 Phosphoric acid solution, slag liquid separation Comparative Example 2 Hydrobromic acid solution, slag liquid separation Comparative Example 3 Hydrobromic acid solution, slag-liquid separation, phosphoric acid solution, slag-liquid separation Comparative Example 4 Phosphoric acid solution, slag-liquid separation, silicic acid solution, slag-liquid separation Comparative Example 5 Lead powder, slag and liquid separation Comparative Example 6 Lead powder, slag-liquid separation, hydrobromic acid solution, slag-liquid separation

[0097] The present invention measured the content of each impurity metal in the wash water after purification using Comparative Examples 1-6, and the results are shown in Table 6:

[0098] Table 6 Content of impurity metals in the purified wash water and unpurified wash water of Example 1 and Comparative Examples 1-6

[0099]

[0100]

[0101] The present invention also sends the purified washing water of Comparative Examples 1-6 to the lead electrolysis solution system for a lead electrolysis test, and determines the content of impurities in the precipitated lead when the washing water is recycled to the lead electrolysis system. The specific operation method is as follows:

[0102] Take 30L of the purified wash water from Comparative Example 1-6 and run it at a current density of 150A / m 2 , a lead electrolysis test was carried out for 36 hours under the condition of an electrolyte circulation rate of 160 ml / min, and the precipitated lead obtained by electrolysis was tested. The test results are shown in Table 7.

[0103] Table 7 Lead impurity content of electrolytically decomposed washing water after purification and unpurified washing water of Example 1 and Comparative Examples 1-6 (×10 -4 / % )

[0104]

[0105] It can be seen from Table 6 and Table 7 that, compared with Comparative Examples 1 and 2, the present invention uses phosphoric acid and hydrobromic acid to jointly treat the lead electrolysis anode mud washing water for impurity metal purification. Compared with the method of using only phosphoric acid and hydrobromic acid for treatment in Comparative Examples 1 and 2, respectively, the content of impurity metals (Cu, Bi, Ag, As, Sb, Sn, Zn, Fe, Cd, Ni) in the washing water can be effectively reduced, so that the content of each impurity metal in the lead recovered into the lead electrolysis solution and precipitated is also lower than that in Comparative Examples 1 and 2, indicating that a better purification effect can be achieved under the joint action of the two acids.

[0106] Compared with Comparative Example 3, when purifying impurity metals in lead electrolysis anode mud washing water, the present invention adopts phosphoric acid purification treatment first and then hydrobromic acid treatment. Compared with the method of first using hydrobromic acid treatment and then phosphoric acid treatment in Comparative Example 3, it has a better effect of reducing the impurity content in the washing water, so that the content of each impurity metal and the total amount of impurities in the recovered lead are also lower than those in Comparative Example 3, indicating that the purification order of phosphoric acid and hydrobromic acid also affects the removal effect of impurity metals in the anode mud washing water;

[0107] Compared with Comparative Example 4, the present invention uses hydrobromic acid to treat the wash water of lead electrolysis anode mud during secondary purification. Compared with the treatment with silicofluoric acid in Comparative Example 4, the content of impurity metals in the wash water can be greatly reduced, so that the content of each impurity metal in the recovered lead and the total amount of impurities are significantly lower than those in Comparative Example 4, indicating that when purifying the wash water, hydrobromic acid used in combination with phosphoric acid has a more significant and superior purification effect than silicofluoric acid, and there are significant differences in the purification effects of different acids;

[0108] Compared with Comparative Example 5, when the present invention uses phosphoric acid and hydrobromic acid to purify anode mud washing water, compared with the method of using only lead powder treatment in Comparative Example 1, the content of each impurity metal can be significantly reduced, so that the content of each impurity metal in the recovered lead is significantly lower than that in Comparative Example 1; even if hydrobromic acid is added for secondary purification treatment on the basis of lead powder purification treatment (i.e. Comparative Example 6), the content of impurity metals in the corresponding washing water is still significantly higher than that in Example 1, and the content of each impurity metal and the total amount of impurities in the recovered lead are significantly higher than those in Example 1. It shows that the purification effect of the washing water when lead powder and hydrobromic acid are used in combination is significantly lower than that of phosphoric acid and hydrobromic acid.

[0109] In summary, only in the present invention, the impurity metals in the lead electrolysis anode mud washing water can be effectively removed and the content of the impurity metals can be significantly reduced. The corresponding impurity metal content and the total amount of impurities in the precipitated lead obtained by returning the washing water to the lead electrolysis solution for lead electrolysis can be greatly reduced, so that it has a better purification effect.

[0110] It should be noted that the terms "primary", "secondary", "first", "second", "third", "fourth", etc. are used herein to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0111] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for purifying impurities in lead electrolysis anode mud washing water, characterized in that: The steps include: 1) Primary purification: stirring the lead electrolysis anode mud washing water, adding the phosphoric acid solution while stirring, and continuing to stir after the addition is completed, so as to purify the impurities in the lead electrolysis anode mud washing water to obtain a primary purified mixed solution; 2) Primary slag-liquid separation: separating the solution and precipitate in the primary purified mixed liquid to obtain primary purified liquid and primary purified slag; 3) Secondary purification: stirring the primary purified liquid, while adding the hydrobromic acid solution to the primary purified liquid while stirring, and continuing to stir after the addition is completed to purify the impurities in the primary purified liquid to obtain a secondary purified mixed liquid; 4) Secondary slag-liquid separation: the solution and the precipitate in the secondary purification mixed liquid are separated to obtain secondary purification liquid and secondary purification slag.

2. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: The primary purified slag obtained in step 2) is sent to a rare metal recovery system or a lead smelting raw material system for valuable metal recovery.

3. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: The secondary purified slag obtained in step 4) is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery, and the secondary purified liquid is sent to a lead electrolytic solution system for recycling.

4. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: In the step 1), the concentration of the phosphoric acid solution is 50-150 g / L, the volume ratio of the phosphoric acid solution to the lead electrolysis anode mud washing water is 1:(10-30), the phosphoric acid solution is added at a speed of 0.1-0.2 L / min, and the stirring time after adding the phosphoric acid solution is continued for 0.5-10 min, and the stirring speed is 300-400 rpm.

5. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: In the step 2), any one of standing, filtering or filter pressing is used to separate the solution and the precipitate in the primary purified mixed solution.

6. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 5, characterized in that: The standing time is 1 to 48 hours.

7. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: In the step 3), the concentration of the hydrobromic acid solution is 50 to 150 g / L, the volume ratio of the hydrobromic acid solution to the primary purification liquid is 1:(10 to 30), the addition rate of the hydrobromic acid solution is 0.1 to 0.2 L / min, and the stirring time after adding the hydrobromic acid solution is 0.5 to 10 min, and the stirring speed is 300 to 400 rpm.

8. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 1, characterized in that: In the step 4), any one of standing, filtering or filter pressing is used to separate the solution and the precipitate in the secondary purified mixed solution.

9. A method for purifying impurities in lead electrolysis anode mud washing water as claimed in claim 8, characterized in that: The standing time is 1 to 48 hours.

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