Method for purifying impurities from lead electrolytic anode slime wash water

Abstract

The application discloses a kind of impurity purification methods of lead electrolysis anode mud wash water, comprising the following steps: 1) primary purification: stirring lead electrolysis anode mud wash water, while stirring, add phosphoric acid solution, continue stirring after adding, obtain primary purification mixture;2) primary residue-liquid separation: solution and precipitate in primary purification mixture are separated, obtain primary purification liquid and primary purification residue;3) secondary purification: stirring primary purification liquid, while stirring, add hydrobromic acid solution to primary purification liquid, continue stirring after adding, obtain secondary purification mixture;4) secondary residue-liquid separation: solution and precipitate in secondary purification mixture are separated, obtain secondary purification liquid and secondary purification residue.The method can effectively remove the impurity metal in lead electrolysis anode mud wash water, greatly reduce the content of impurities in the lead precipitated by recycling wash water to lead electrolysis solution system, and realize the resource utilization of purification residue.

Description

Technical Field

[0001] This invention relates to the field of lead electrolytic refining technology, and in particular to a method for purifying impurities in lead electrolytic anode mud washing water. Background Technology

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

[0003] To recover valuable metals and acid lead resources from anode mud, the anode mud is often washed with water and filtered to obtain anode mud and anode mud wash water. The anode mud is then sent directly to a rare and precious metal recovery system to recover valuable metals, while the anode mud wash water is often directly entered into the crude lead electrolysis system for recycling. However, the anode mud wash water has a high content of impurity metals such as Zn, Fe, Cu, Ag, Sn, and Bi, which is a high-impurity enrichment area in the lead electrolysis system solution. If it is directly entered into the crude lead electrolysis system without purification treatment, it is easy to cause the impurities in the precipitated lead to exceed the standard.

[0004] Currently, existing technologies address the problem of impurity purification in lead electrolysis anode mud washing water. For example, patent application CN201810846031.7 discloses a process for removing impurities from lead anode mud washing water. This process primarily involves adding 200-mesh lead powder to the lead anode mud washing water solution under normal temperature and pressure conditions, followed by mechanical stirring in a purification tank for 6 hours. This achieves a bismuth replacement rate of 96.99% and an antimony replacement rate of 76.69%. After replacement, the anode mud filter water essentially achieves purification and impurity removal, while lead ions in the lead anode mud can be relatively completely returned to the electrolyte circulation system, resulting in a relatively stable electrolyte composition.

[0005] This impurity removal process utilizes lead powder and Bi... 3+ and Sb 3+ The displacement reaction removes bismuth and antimony. However, the anode mud wash water does not only contain impurity metals Bi and Sb, but also impurity metals such as Cu, Ag, Sn, Zn, Fe, Cd, and Ni. These impurity metals will still cause the anode mud wash water to be enriched in the lead electrolysis system solution when it is recycled to the lead electrolysis system, and enter the lead electrolyzed, causing the impurities in the lead to exceed the standard. This further leads to a serious over-limit of the total amount of impurities in the lead, which greatly reduces 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 electrolytic anode mud washing water. This method can effectively remove impurity metals in lead electrolytic anode mud washing water and greatly reduce the content of impurities in lead precipitated when the washing water is recycled to the lead electrolytic solution system.

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

[0008] 1) Primary purification: Stir the lead electrolytic anode mud washing water while adding phosphoric acid solution. After the addition is complete, continue stirring to purify the impurities in the lead electrolytic anode mud washing water and obtain a primary purified mixture.

[0009] 2) Primary sludge-liquid separation: The solution and precipitate in the primary purification mixture are separated to obtain primary purification liquid and primary purification sludge;

[0010] 3) Secondary purification: Stir the primary purification solution while adding hydrobromic acid solution. After the addition is complete, continue stirring to purify the impurities in the primary purification solution and obtain a secondary purified mixture.

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

[0012] In purifying the washing water of lead electrolysis anode mud, this invention first uses a phosphoric acid solution to purify the anode mud washing water, thereby reducing the Zn content in the solution. 2+ Fe 2+ Cd 2+ Ni 2+ Sn 2+ Bi 3+ Cu 2+ Ag + The chemical reactions that occur during a single purification step include: The reaction with phosphoric acid solution produces insoluble or slightly soluble salts that precipitate out of the solution.

[0013] 3Zn 2+ +2PO4 3- =Zn3(PO4)2↓

[0014] 3Fe 2+ +2PO4 3- =Zn3(PO4)2↓

[0015] 3Cd 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, physical methods (such as settling, filtration, pressure filtration, etc.) are used to separate the solution and precipitate in the primary purified mixture obtained from the primary purification to obtain the primary purified liquid and the primary purified residue.

[0022] During the process of experimentation, the inventors discovered that the Cd in the primary purified solution obtained after treatment with phosphoric acid solution... 2+ Bi 3+ Ag + and Sb 3+ The presence of impurity metals still causes the lead extracted in subsequent electrolytic lead-based solutions to exceed impurity limits. To further reduce impurities in the wash water, multiple experiments revealed that hydrobromic acid can effectively remove impurity metals from the primary purification solution. Therefore, after the primary purification treatment, a secondary purification process using hydrobromic acid solution is performed to further purify the primary purification solution, reducing the Cd content in the primary purification solution. 2+ Bi 3+ Ag + and Sb 3+ It reacts with hydrobromic acid to form insoluble or slightly soluble salts that precipitate out of the solution. The chemical reactions that occur in the secondary purification step include:

[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., secondary purification solution) obtained after two purification processes can be effectively reduced, so that the content of impurity metals in the wash water returned to the lead electrolysis solution is relatively small. This greatly reduces the content of impurity metals that are deposited with lead during electrolysis in the lead electrolysis system, thereby reducing the content of impurity metals in the deposited lead and thus reducing the total amount of impurities in the lead, so that the refined lead obtained meets the standards.

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

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

[0030] Furthermore, in 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 electrolytic anode mud washing water is 1:(10-30), the phosphoric acid solution is added at a rate of 0.1-0.2 L / min, and the stirring time after adding the phosphoric acid solution is 0.5-10 min, with a stirring speed of 300-400 rpm.

[0031] Furthermore, in step 2), any one of the following methods—separation by standing, filtration, or pressure filtration—is used to separate the solution and precipitate in the primary purified mixture.

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

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

[0034] Furthermore, in step 4), any one of the following methods—separation by standing, filtration, or pressure filtration—is used to separate the solution and precipitate in the secondary purified mixture.

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

[0036] The beneficial effects of the present invention on the purification of impurities in the washing water of lead electrolytic anode mud are as follows:

[0037] (1) The method of this invention is simple. Addressing the problem of impurity metals in the lead electrolysis anode mud washing water, it first uses phosphoric acid solution to purify the anode mud washing water, achieving primary purification of Zn, Fe, Cd, Ni, Sn, Bi, Cu, and Ag impurities. Then, it uses hydrobromic acid solution to further purify the primary purified solution, further purifying Cd, Bi, and Ag that were not completely purified in the first treatment, and simultaneously removing unpurified Sb. The combined use of phosphoric acid and hydrobromic acid effectively removes impurity metals (Zn, Fe, Cd, Ni, Sn, Bi, Cu, Ag, Sb) from the anode mud washing water. When the washing water purified by this invention is recycled back to the lead electrolysis solution, the content of these impurity metals in the lead electrolysis solution is reduced. This effectively reduces the phenomenon of impurity metals precipitating along with lead during lead electrolysis, thereby significantly reducing the content of each impurity metal and the total amount of impurities in the precipitated lead, ensuring that the precipitated lead meets the standard requirements and improving the quality of refined lead.

[0038] (2) In this invention, the primary and secondary purification slags obtained in the primary and secondary purification processes are sent to the rare and precious metal recovery system or the lead smelting raw material system for the recovery of valuable metals, and the secondary purification liquid is sent to the lead electrolysis solution system for recycling. This allows the slag and purification liquid generated in the entire purification process to be recycled and reused without introducing new impurities. The entire process does not generate waste gas, waste residue, wastewater or other wastes, thus realizing the resource utilization of anode mud washing water and purification slag. Attached Figure Description

[0039] Figure 1 —This is a process flow diagram of a method for purifying impurities in lead electrolytic anode mud washing water according to the present invention. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these specific embodiments do not limit the scope of protection of the present invention in any way.

[0041] To compare the impurity removal effect of the present invention, the lead electrolytic anode mud washing water shown in Table 1 was used for purification and related testing experiments in the following examples and comparative examples.

[0042] Table 1. Impurity content in washing water of industrial lead electrolytic anode mud

[0043]

[0044] The electrolytic anode mud wash water shown in Table 1 was sent to the lead electrolysis solution system for lead electrolysis experiments. The content of impurity metals in the lead precipitated when the anode mud wash water that had not been purified was recovered into the lead electrolysis system was determined. The specific operating method is as follows:

[0045] Take 30L of the lead electrolytic anode mud washing water shown in Table 1 and apply it at a current density of 150A / m³. 2 A 36-hour lead electrolysis experiment was conducted under the condition that the electrolyte circulation rate was 160 ml / min. The content of various impurity metals in the electrolyzed lead was detected, and the detection results are shown in Table 2.

[0046] Table 2 Lead impurity content from electrolytic analysis of untreated anode mud wash water (×10) -4 / %)

[0047]

[0048] 30L at a current density of 150A / m 2 A 36-hour lead electrolysis experiment was conducted under the condition that the electrolyte circulation rate was 160 ml / min. The deposited lead obtained by electrolysis was tested, and the test results are shown in Table 2.

[0049] Example 1

[0050] A method for purifying impurities in lead electrolytic anode mud washing water, the process flow diagram of which is shown below. Figure 1 As shown, it includes the following steps:

[0051] 1) Primary purification: Take 30L of lead electrolytic anode mud washing water as shown in Table 1 and stir it at 300 rpm. Then, while stirring, add 1.5L of 100g / L phosphoric acid solution at a rate of 0.2L / min. After the addition is completed, continue stirring for 5min to purify the impurities in the lead electrolytic anode mud washing water and obtain a primary purified mixture.

[0052] 2) Primary slag-liquid separation: The primary purification mixture is filtered to separate the solution and precipitate, resulting in primary purification liquid and primary purification slag; the primary purification slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery.

[0053] 3) Secondary purification: The primary purification solution is stirred at 300 rpm, and 1.5 L of 100 g / L hydrobromic acid solution is added to the primary purification solution at a rate of 0.2 L / min. After the addition is completed, stirring is continued for 5 min to purify the impurities in the primary purification solution and obtain the secondary purification mixture.

[0054] 4) Secondary slag-liquid separation: The secondary purified mixture is filtered to separate the solution and precipitate, resulting in secondary purified liquid and secondary purified slag. The primary purified slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to a lead electrolysis solution system for recycling.

[0055] Example 2

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

[0057] 1) Primary purification: Take 30L of lead electrolytic anode mud washing water as shown in Table 1 and stir it at 400 rpm. Then, while stirring, add 1L of 150g / L phosphoric acid solution at a rate of 0.1L / min. After the addition is completed, continue stirring for 5min to purify the impurities in the lead electrolytic anode mud washing water and obtain a primary purified mixture.

[0058] 2) Primary slag-liquid separation: The primary purification mixture is filtered to separate the solution and precipitate, resulting in primary purification liquid and primary purification slag; the primary purification slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery.

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

[0060] 4) Secondary slag-liquid separation: The secondary purified mixture is filtered to separate the solution and precipitate, resulting in secondary purified liquid and secondary purified slag. The primary purified slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to a lead electrolysis solution system for recycling.

[0061] Example 3

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

[0063] 1) Primary purification: Take 30L of lead electrolytic anode mud washing water as shown in Table 1 and stir it at 350 rpm. Then, while stirring, add 3L of 50g / L phosphoric acid solution at a rate of 0.15L / min. After the addition is completed, continue stirring for 5min to purify the impurities in the lead electrolytic anode mud washing water and obtain a primary purified mixture.

[0064] 2) Primary slag-liquid separation: The primary purification mixture is filtered to separate the solution and precipitate, resulting in primary purification liquid and primary purification slag; the primary purification slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery.

[0065] 3) Secondary purification: Stir the primary purification solution at 400 rpm, and simultaneously add 3 L of 75 g / L hydrobromic acid solution to the primary purification solution at a rate of 0.1 L / min. After the addition is completed, continue stirring for 5 min to purify the impurities in the primary purification solution and obtain the secondary purification mixture.

[0066] 4) Secondary slag-liquid separation: The secondary purified mixture is filtered to separate the solution and precipitate, resulting in secondary purified liquid and secondary purified slag. The primary purified slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to a lead electrolysis solution system for recycling.

[0067] The present invention determined the content of various impurity metals 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 various impurity metals in the purified and unpurified wash water of Examples 1-3

[0069]

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

[0071] Take 30L of the purified wash water (secondary purified liquid) from Examples 1-3 and apply it at a current density of 150A / m 2 A 36-hour lead electrolysis experiment was conducted under the condition that the electrolyte circulation rate was 160 ml / min. The deposited lead obtained by electrolysis was tested, and the test results are shown in Table 4.

[0072] Table 4 Lead impurity content (×10) of purified and unpurified wash water from Examples 1-3 after electrolysis -4 / %)

[0073]

[0074] As shown in Table 3, compared with the unpurified lead electrolytic anode mud wash water (i.e., the unpurified wash water shown in Table 1), the purification of impurities in the wash water after using the method of the present invention in Examples 1-3 can significantly reduce the impurity metals Cu, Bi, Ag, As, Sb, Sn, Zn, Fe, Cd, and Ni in the wash water.

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

[0076] Combined with Tables 3 and 4, it is shown that the purification method of the present invention can effectively remove impurities from the lead electrolysis anode mud wash water, thereby greatly reducing the content of impurity metals returned to the lead electrolysis solution through the wash water. Furthermore, it will reduce the content of impurity metals deposited with lead during electrolysis, thus significantly reducing the content of each metal impurity in the deposited lead. This ensures that the content of each impurity and the total amount of impurities in the deposited lead do not exceed the standard and all meet the GB / T 469-2023 Pb99.996 standard, thereby improving the quality of the deposited lead.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that it does not include step 3) secondary purification and step 4) secondary sludge-liquid separation.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 1 is that it does not include step 1) primary purification and step 2) primary slag-liquid separation. Instead, the lead electrolysis anode mud washing water is directly purified with hydrobromic acid solution, that is, it is directly treated by step 3) secondary purification and step 4) secondary slag-liquid separation.

[0081] Comparative Example 3

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

[0083] Comparative Example 4

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

[0085] Comparative Example 5

[0086] This comparative example uses lead powder to purify the washing water of lead electrolytic anode mud. The specific operation method is as follows:

[0087] Fine lead powder of 150 mesh or higher is added to the lead electrolysis anode mud washing water at a liquid-solid ratio of 20:1. The mixture is then stirred for 5 minutes at a stirring speed of 300 rpm to obtain a purified mixture. The solution and precipitate in the purified mixture are then separated by filtration to obtain purified residue and purified liquid. The purified residue is sent to a rare and precious metal recovery system or a lead smelting raw material system for the recovery of valuable metals. The purified liquid is sent to a lead electrolysis solution system for recycling.

[0088] Comparative Example 6

[0089] This comparative example first uses lead powder to purify the lead electrolysis anode mud washing water and separate the sludge from the liquid, and then uses hydrobromic acid to purify the lead electrolysis anode mud washing water and separate the sludge from the liquid. The specific operation method is as follows:

[0090] 1) Primary purification: Add fine lead powder of 150 mesh or higher to the lead electrolytic 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 purification mixture.

[0091] 2) Primary slag-liquid separation: The primary purification mixture is filtered to separate the solution and precipitate, resulting in primary purification liquid and primary purification slag; the primary purification slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery.

[0092] 3) Secondary purification: The primary purification solution is stirred at 300 rpm, and 1.5 L of 100 g / L hydrobromic acid solution is added to the primary purification solution at a rate of 0.2 L / min. After the addition is completed, stirring is continued for 5 min to purify the impurities in the primary purification solution and obtain the secondary purification mixture.

[0093] 4) Secondary slag-liquid separation: The secondary purified mixture is filtered to separate the solution and precipitate, resulting in secondary purified liquid and secondary purified slag. The primary purified slag is sent to a rare and precious metal recovery system or a lead smelting raw material system for valuable metal recovery; the secondary purified liquid is sent to a lead electrolysis solution system for recycling.

[0094] The differences between the purification methods of Example 1 and Comparative Examples 1-6 in this invention are shown in the table below:

[0095] Table 5. Differences between the purification methods in Example 1 and Comparative Examples 1-6

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

[0097] The present invention determined the content of various impurity metals in the wash water purified by comparative examples 1-6, and the results are shown in Table 6:

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

[0099]

[0100]

[0101] This invention also includes lead electrolysis tests on the purified wash water from Comparative Examples 1-6, which were then sent to a lead electrolysis solution system to determine the content of impurities in the lead precipitated when the wash water was recovered to the lead electrolysis system. The specific operating method is as follows:

[0102] Take 30L of purified wash water from Comparative Examples 1-6 and apply it at a current density of 150A / m³. 2 A 36-hour lead electrolysis experiment was conducted under the condition that the electrolyte circulation rate was 160 ml / min. The deposited lead obtained by electrolysis was tested, and the test results are shown in Table 7.

[0103] Table 7 Lead impurity content (×10) of purified and unpurified wash water from Examples 1 and 6, as determined by electrolysis. -4 / %)

[0104]

[0105] As shown in Tables 6 and 7, compared with Comparative Examples 1 and 2, the present invention uses both phosphoric acid and hydrobromic acid to treat the lead electrolysis anode mud wash water for impurity metal purification. Compared with the methods of Comparative Examples 1 and 2, which only use phosphoric acid and hydrobromic acid, the present invention can effectively reduce the content of impurity metals (Cu, Bi, Ag, As, Sb, Sn, Zn, Fe, Cd, Ni) in the wash water. As a result, 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. This shows that a better purification effect can be achieved under the combined action of the two acids.

[0106] Compared with Comparative Example 3, the present invention uses phosphoric acid purification followed by hydrobromic acid purification when purifying impurity metals in lead electrolysis anode mud wash water. Compared with the method of using hydrobromic acid treatment followed by phosphoric acid treatment in Comparative Example 3, this method has a better effect on reducing the impurity content in the wash water. 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. This shows that the purification order of phosphoric acid and hydrobromic acid also affects the removal effect of impurity metals in anode mud wash water.

[0107] Compared with Comparative Example 4, the present invention uses hydrobromic acid for secondary purification of lead electrolytic anode mud washing water. Compared with the use of fluorosilicic acid in Comparative Example 4, it can greatly reduce the content of impurity metals in the washing water. As a result, the content of each impurity metal and the total amount of impurities in the recovered lead are significantly lower than those in Comparative Example 4. This shows that when purifying washing water, hydrobromic acid used in combination with phosphoric acid has a more significant and superior purification effect than fluorosilicic acid. The purification effects of different acids are significantly different.

[0108] Compared to Comparative Example 5, the present invention, using a combination of phosphoric acid and hydrobromic acid to purify the anode mud wash water, significantly reduces the content of various impurity metals compared to the lead powder treatment method in Comparative Example 5, resulting in a significantly lower content of various impurity metals in the recovered lead compared to Comparative Example 5. Even with the addition of hydrobromic acid for secondary purification on top of lead powder purification (i.e., Comparative Example 6), the content of impurity metals in the wash water is still significantly higher than in Example 1, and both the content of various impurity metals and the total amount of impurities in the recovered lead are significantly higher than in Example 1. This indicates that the purification effect of using lead powder and hydrobromic acid together on the wash water is significantly lower than that of using phosphoric acid and hydrobromic acid together.

[0109] In summary, only by employing phosphoric acid for primary purification followed by hydrobromic acid for secondary purification in this invention can the impurity metals in the lead electrolysis anode mud wash water be effectively removed, significantly reducing the content of impurity metals. Furthermore, the content and total amount of impurity metals in the precipitated lead obtained by returning the wash water to the lead electrolysis solution are greatly reduced, resulting in a better purification effect.

[0110] It should be noted that this article uses the terms "first," "second," "first," "second," "third," "fourth," etc., to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another.

[0111] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for purifying impurities from wash water of lead electrolytic anode slime, characterized by, The method comprises the following steps: 1) primary purification: stirring the lead electrolysis anode mud washing water while adding phosphoric acid solution, continuing to stir after the addition is completed, so that the impurities in the lead electrolysis anode mud washing water are purified, and a primary purification mixture is obtained; 2) primary residue-liquid separation: separating the solution and the precipitate in the primary purification mixture, so that a primary purification liquid and a primary purification residue are obtained; 3) secondary purification: stirring the primary purification liquid while adding hydrobromic acid solution to the primary purification liquid, continuing to stir after the addition is completed, so that the impurities in the primary purification liquid are purified, and a secondary purification mixture is obtained; 4) secondary residue-liquid separation: separating the solution and the precipitate in the secondary purification mixture, so that a secondary purification liquid and a secondary purification residue are obtained.

2. The method for purifying impurities from the wash water of lead electrolytic anode slime according to claim 1, characterized in that: The primary purification residue obtained in the step 2) is sent to a rare and precious metal recovery system or a lead smelting raw material system for value metal recovery.

3. The method of purifying impurities from the wash water of lead electrolytic anode slime according to claim 1, characterized in that: The secondary purification residue obtained in the step 4) is sent to a rare and precious metal recovery system or a lead smelting raw material system for value metal recovery, and the secondary purification liquid is sent to a lead electrolysis solution system for recycling.

4. The method for purifying impurities of lead electrolytic anode slime wash water according to 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 adding speed of the phosphoric acid solution is 0.1-0.2 L / min, and the stirring time after the phosphoric acid solution is added is 0.5-10 min, and the stirring speed is 300-400 rpm.

5. The method of purifying impurities from the wash water of lead electrolytic anode slime according to claim 1, characterized in that, In the step 2), any one of standing, filtering or pressure filtering is used to separate the solution and the precipitate in the primary purification mixture.

6. A process for the purification of wash water from lead electrolytic anode slime as claimed in claim 5, wherein the process comprises: The standing time is 1-48 h.

7. The method of purifying impurities from the wash water of lead electrolytic anode slime according to claim 1, characterized in that, In the step 3), the concentration of the hydrobromic acid solution is 50-150 g / L, the volume ratio of the hydrobromic acid solution to the primary purification liquid is 1:(10-30), the adding speed of the hydrobromic acid solution is 0.1-0.2 L / min, and the stirring time after the hydrobromic acid solution is added is 0.5-10 min, and the stirring speed is 300-400 rpm.

8. The method for purifying impurities from the wash water of lead electrolytic anode slime according to claim 1, characterized in that, In the step 4), any one of standing, filtering or pressure filtering is used to separate the solution and the precipitate in the secondary purification mixture.

9. A process for the purification of wash water from lead electrolytic anode slime as claimed in claim 8, wherein, The standing time is 1-48 h.

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