A method for efficiently recovering manganese and lead in zinc anode slime with the aid of a reducing agent

Abstract

The application discloses a method for recovering manganese and lead in zinc anode slime with the aid of a reducing agent, and belongs to the field of hydrometallurgy. The method for recovering manganese and lead in zinc anode slime uses thiourea as a reducing agent, dilute sulfuric acid as a leaching agent to extract metal manganese and lead in zinc anode slime, and obtains high-value elemental sulfur. In addition, ammonium acetate and oxalic acid are used as a leaching agent and a precipitant respectively to separate lead and sulfur from acid leaching residue. The recovery method has mild reaction conditions, high leaching rate, small residue amount, low cost and is easy to produce.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, and in particular to a method for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent. Background Technology

[0002] In the zinc concentrate leaching process, a certain amount of MnO2 is usually added to improve the zinc leaching rate. Therefore, the zinc leachate contains a certain concentration of Mn. 2+ During zinc electrowinning, Mn 2+ After anodizing, MnO2 is formed and adheres to the anode, is suspended in the electrolyte, and settles at the bottom of the anode. Furthermore, the anodes used in zinc electrowinning are typically Pb-Ag alloy plates with an Ag content of 0.8%. After prolonged electrolysis, the surface of the Pb-Ag alloy anode corrodes and dissolves, causing Pb and Ag to be oxidized and dissolved into the electrolyte. Pb ultimately forms lead dioxide (PbO2) or lead sulfate (PbSO4), which settles at the bottom of the electrolytic cell. The zinc anode sludge produced after long cycles is mainly composed of MnO2, with some PbO2, PbSO4, AgCl, and Ag2O3. Besides being reused for zinc concentrate leaching, some zinc anode sludge remains. Directly discarding it would result in significant resource waste and pollution of the surrounding environment. Therefore, its recycling and utilization are urgently needed to improve production efficiency.

[0003] Currently, the main technologies for recovering valuable metals from waste zinc anode sludge are pyrometallurgical and hydrometallurgical methods. Pyrometallurgical recovery technology is simple to operate and can be applied on a large scale industrially, but it has certain equipment requirements and consumes a large amount of energy during the processing of zinc anode sludge. The gases produced during roasting (such as SO2) are harmful to the environment and require tail gas treatment. Compared to pyrometallurgical recovery, hydrometallurgical recovery technology is more widely used, with advantages such as low reaction temperature and high leaching rate. A representative patent for recovering valuable metals from zinc anode sludge is as follows: Patent 201210057504.8 uses oxalic acid and sulfuric acid as reducing agents and leaching agents to recover valuable metals from zinc anode sludge. This method is simple to operate and has a high recovery rate of valuable metals. However, it generates a large amount of leaching residue during the leaching process, and introduces sulfur during the removal of impurities from the leaching solution. 2- and F -This process results in the loss of some manganese and affects the purity of manganese products. Patent 201810222229.8 describes mixing charcoal powder or carbon black with zinc anode mud, microwaving it, and then leaching it with sulfuric acid to obtain a leachate containing manganese sulfate and an acid leaching residue containing silver and lead sulfate. The manganese sulfate leachate is neutralized with ammonium bicarbonate and then purified with ammonium sulfide to remove lead, zinc, and silver impurities, yielding a purified manganese sulfate solution and a purified residue. The purified manganese sulfate solution is then prepared with ammonia, ammonium sulfate, and electrolytic additives for the electrolysis of metallic manganese. This method has a short reduction roasting time, low temperature, thorough roasting, and high reduction rate, but it requires certain equipment and the recovery process is relatively complex. Patent 201110091813.2 uses hydrogen peroxide and sulfuric acid as reducing and leaching agents to recover valuable metals from zinc anode mud. This method is simple, energy-efficient, and environmentally friendly. However, this method results in the loss of some manganese when barium sulfide is added to the leaching solution for impurity removal; furthermore, this method only involves the recovery of manganese and does not achieve the comprehensive recovery of metallic lead from zinc anode mud. Patent 201010531602.1 uses sulfur dioxide generated from acid production to reduce manganese in zinc anode mud, achieving the separation of manganese from lead and silver. This method is simple and environmentally friendly; however, the purity of the obtained manganese product is low, and SO2 tail gas treatment is required. Therefore, there is an urgent need for a zinc anode mud recovery method with high leaching rate, low pollution, low energy consumption, minimal loss, high purity of MnO2 product, and small slag volume. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent, thereby solving problems such as low recovery rate, large slag volume, high recovery cost, low product purity, and poor environmental friendliness in the process of recovering valuable metals from zinc anode mud.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent, comprising the following steps:

[0007] (1) The zinc anode mud was washed and dried, mixed with a reducing agent, added to sulfuric acid, stirred, reacted at a constant temperature, filtered and separated to obtain a leachate containing manganese ions and an acid leaching residue containing lead sulfate and elemental sulfur.

[0008] (2) Add sulfuric acid to the leachate containing manganese ions, electrolyze, and obtain elemental sulfur and manganese dioxide by electrolysis at the anode by monitoring the anode potential.

[0009] (3) The acid leaching residue containing lead sulfate and elemental sulfur is mixed with ammonium acetate solution, stirred and reacted at a constant temperature, and filtered to obtain a filtrate containing lead ions and insoluble sulfur residue;

[0010] (4) The lead-containing filtrate is precipitated with oxalic acid solution, and after filtration and separation, lead oxalate solid is obtained. The lead oxalate solid is oxidized and roasted to obtain lead tetroxide. The insoluble sulfur residue is dissolved in toluene and then distilled to recover elemental sulfur.

[0011] Preferably, in step (1), the reducing agent is thiourea. Under acidic conditions, thiourea has strong reducing properties and undergoes a redox reaction with zinc anode mud, reducing MnO2 to MnSO4 which enters the acid leaching solution. Therefore, the leaching rate of Mn is high, and the amount of remaining slag is small. After the zinc anode mud is partially recovered from Mn, Pb, and S, the amount of remaining slag is even smaller, so the overall amount of slag produced is small. The high purity of MnO2 is due to the dilution of the acid leaching solution with dilute sulfuric acid before electrolysis, which reduces the impurity ions (Pb... 2+ Fe 3+ The high purity of Pb3O4 is due to the leaching of the acid residue with ammonium acetate, where only PbSO4 is leached out, so the solution contains only Pb ions. 2+ No other impurity cations were introduced during the oxalic acid precipitation and oxidative roasting process, resulting in high purity Pb3O4. Under the same conditions, the more thiourea added, the higher the Mn leaching rate and the more elemental sulfur produced; the higher the sulfuric acid concentration, the higher the Mn leaching rate.

[0012] Preferably, in step (1), the mass ratio of zinc anode mud to reducing agent is 0.8–2; the concentration of sulfuric acid is 150–250 g / L; the solid-liquid ratio is 100–300 g / L; the stirring rate is greater than 300 rpm; the reaction temperature is 40–60 °C; and the reaction time is 1–4 h. In this step, the zinc anode mud undergoes a redox reaction with the reducing agent. Utilizing the strong reducing properties of thiourea under acidic conditions, a large amount of MnO2 in the zinc anode mud is reduced to MnSO4, which then enters the acid leaching solution. The focus of this invention is on the thiourea-based reducing agent and the Mn recovery route, while weakening the Pb recovery; however, judging from the XRD pattern of Pb3O4, there are almost no impurity peaks, so its purity is assumed to be approximately 100%, and the recovery rate is approximately 90%.

[0013] Preferably, in step (2), the sulfuric acid concentration is 50 g / L; the pH of the leachate after sulfuric acid treatment is 0, and the manganese ion concentration is 25 g / L; the electrolysis temperature is 80 °C, and the current density is 6 mA / cm². 2 In this step, the sulfuric acid treatment not only adjusts the pH of the leachate but also dilutes the concentration of manganese ions and impurity ions, thereby increasing the purity of the MnO2 obtained by electrolysis.

[0014] Preferably, in step (3), the concentration of ammonium acetate solution is 40–160 g / L; the stirring rate is greater than 300 rpm; the reaction temperature is 40–80 °C; and the reaction time is 0.5–3 h. In this step, after adding ammonium acetate solution, insoluble lead sulfate is converted into soluble lead acetate.

[0015] Preferably, in step (4), the concentration of the oxalic acid solution is 45 g / L; the oxidative roasting temperature is 500℃ and the oxidative roasting time is 5 h. In this step, after adding the oxalic acid solution, lead acetate is converted into lead oxalate precipitate; after oxidative roasting, lead oxalate is converted into lead tetroxide.

[0016] The present invention discloses the following technical effects:

[0017] This invention provides a method for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent. Ammonium acetate and oxalic acid are used as the leaching agent and precipitating agent for lead, respectively, to separate lead and sulfur from the acid leaching residue. This recovery method features mild reaction conditions, high leaching rate, small residue volume, no production of toxic or harmful gases, is environmentally friendly, and is low-cost and easy to produce. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the process for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent, as described in this invention.

[0020] Figure 2 This is a photograph of the acid leaching residue from Example 1;

[0021] Figure 3 The image shows the XRD pattern of the acid leaching residue from Example 1.

[0022] Figure 4 This is a photograph of lead tetroxide from Example 1.

[0023] Figure 5 The XRD pattern of lead tetroxide in Example 1 is shown.

[0024] Figure 6 This is a photograph of the electrolytic sulfur process in Example 1;

[0025] Figure 7 The image shows the XRD pattern of sulfur electrolysis in Example 1.

[0026] Figure 8 This is a photograph of the electrolytic manganese dioxide sample from Example 1.

[0027] Figure 9 The image shows the XRD pattern of electrolytic manganese dioxide in Example 1. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] Schematic diagrams of the process for efficient recovery of manganese and lead from zinc anode mud using reducing agents in various embodiments of the present invention are shown below. Figure 1 .

[0034] Comparative Example 1

[0035] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 400rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 0.8. After filtration, a manganese ion leaching solution containing 85.52g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.41g are obtained.

[0036] (2) At a temperature of 80℃ and a current density of 6mA / cm 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 90.78%, and the purity was over 90%, which did not meet the national first-class MnO2 standard (ZBG13001-86).

[0037] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. Filter to obtain filtrate containing lead ions and 1.31g of sulfur residue.

[0038] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity lead tetroxide (Pb3O4) product was obtained. After dissolving the sulfur residue in 10 mL of toluene, it was distilled to obtain 0.76 g of elemental sulfur and 0.49 g of waste residue. The total residue amount was reduced by 93.12%.

[0039] Example 1

[0040] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 400rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.12g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.61g are obtained.

[0041] (2) Adjust the pH of the manganese ion leaching solution to 0 using 50 g / L H2SO4, and adjust the Mn content to 0. 2+ Concentration diluted to 25 g / L (after leaching, the pH of the acid leaching solution is between 0 and 1, Mn 2+ With a concentration of approximately 85 g / L, adding a certain volume of 50 g / L H2SO4 can simultaneously adjust the pH of the leachate to 0, and Mn 2+ The concentration was diluted to 25 g / L (where 0 and 25 g / L are approximate values, rounded off), and then tested at a temperature of 80℃ and a current density of 6 mA / cm². 2Electrolysis was performed sequentially at the anode by monitoring the anode potential to obtain high-value-added elemental sulfur and manganese dioxide. The manganese recovery rate was 90.86%, and the purity was over 90%, meeting the national first-class MnO2 standard (ZBG13001-86).

[0042] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. Filter to obtain filtrate containing lead ions and 1.31g of sulfur residue.

[0043] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity lead tetroxide (Pb3O4) product was obtained. After dissolving the sulfur residue in 10 mL of toluene, it was distilled to obtain 0.76 g of elemental sulfur and 0.49 g of waste residue. The total residue amount was reduced by 93.12%.

[0044] See the physical image of the acid leaching residue from Example 1. Figure 1 XRD pattern of acid leaching residue in Example 1 is shown below. Figure 2 Example 1: A physical image of lead tetroxide is shown below. Figure 3 Example 1: XRD pattern of lead tetroxide (Pb3O4) is shown in [reference needed]. Figure 4 From the XRD pattern of Pb3O4, there are almost no impurity peaks, so its purity is assumed to be approximately 100%, and the recovery rate is approximately 90%; see the physical image of the electrolytic sulfur in Example 1. Figure 5 XRD pattern of sulfur electrolysis in Example 1 is shown below. Figure 6 Example 1: Electrolytic manganese dioxide physical sample image (see attached image). Figure 7 Example 1: XRD pattern of electrolytic manganese dioxide (see...) Figure 8 .

[0045] Example 2

[0046] (1) Take 20g of zinc anode mud and 20g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it, control the stirring speed to 400rpm, the solid-liquid ratio to 200g / L, and react at 60℃ for 4h. After the reaction, the pH of the solution is 1.2. After filtration, a manganese ion leaching solution containing 81.22g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.11g are obtained.

[0047] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 92.54%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0048] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 3h. After filtration, obtain a filtrate containing lead ions and 1.13g of sulfur residue.

[0049] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.69 g of elemental sulfur and 0.39 g of waste residue. The total residue amount was reduced by 95.01%.

[0050] Example 3

[0051] (1) Take 20g of zinc anode mud and 15g of thiourea into a 250mL conical flask, pour in 100mL of 200g / L H2SO4 solution, stir at 400rpm, and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 0.1. After filtration, a manganese ion leaching solution containing 80.67g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 4.81g are obtained.

[0052] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 91.29%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0053] (3) Take 1.5g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain a filtrate containing lead ions and 0.92g of sulfur residue.

[0054] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and calcining at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.55 g of elemental sulfur and 0.32 g of waste residue. The total residue amount was reduced by 94.83%.

[0055] Example 4

[0056] (1) Take 10g of zinc anode mud and 5g of thiourea into a 250mL conical flask, pour in 50mL of 150g / L H2SO4 solution, stir at 400rpm, and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 0.6. After filtration, a manganese ion leaching solution containing 87.27g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 2.16g are obtained.

[0057] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of anode potential. The manganese recovery rate is 90.40%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0058] (3) Take 1g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. Filter to obtain filtrate containing lead ions and 0.67g of sulfur residue.

[0059] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and calcining at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.40 g of elemental sulfur and 0.23 g of waste residue. The total amount of residue was reduced by 94.14%.

[0060] Example 5

[0061] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 66.7mL of 200g / L H2SO4 solution into it. Stir at 500rpm and the solid-liquid ratio is 300g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 3. After filtration, a manganese ion leaching solution containing 70.12g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 7.32g are obtained.

[0062] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 92.28%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0063] (3) Take 4g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain filtrate containing lead ions and 2.43g of sulfur residue.

[0064] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 1.52 g of elemental sulfur and 0.85 g of waste residue. The total residue amount was reduced by 92.21%.

[0065] Example 6

[0066] (1) Take 20g of zinc anode mud and 25g of thiourea into a 250mL conical flask, pour in 200mL of 200g / L H2SO4 solution, stir at 300rpm, and the solid-liquid ratio is 100g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 0.5. After filtration, a manganese ion leaching solution containing 88.16g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.91g are obtained.

[0067] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 90.71%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0068] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 1h. After filtration, obtain a filtrate containing lead ions and 1.13g of sulfur residue.

[0069] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. After dissolving the sulfur residue in 10 mL of toluene, it was distilled to obtain 0.71 g of elemental sulfur and 0.39 g of waste residue. The total amount of residue was reduced by 94.15%.

[0070] Example 7

[0071] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 300rpm and the solid-liquid ratio is 200g / L. React at 40℃ for 4h. After the reaction, the pH of the solution is 1.3. After filtration, a manganese ion leaching solution containing 81.13g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.92g are obtained.

[0072] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 90.49%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0073] (3) Take 2g of acid leaching residue and 50mL of 80g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.23g of sulfur residue.

[0074] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.75 g of elemental sulfur and 0.43 g of waste residue. The total amount of residue was reduced by 93.63%.

[0075] Example 8

[0076] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 300rpm and the solid-liquid ratio is 200g / L. React at 50℃ for 4h. After the reaction, the pH of the solution is 1.1. After filtration, a manganese ion leaching solution containing 83.43g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.73g are obtained.

[0077] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 91.00%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0078] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 80℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.16g of sulfur residue.

[0079] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.69 g of elemental sulfur and 0.41 g of waste residue. The total amount of residue was reduced by 94.12%.

[0080] Example 9

[0081] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 300rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 3h. After the reaction, the pH of the solution is 0.9. After filtration, a manganese ion leaching solution containing 84.12g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.73g are obtained.

[0082] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 91.23%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0083] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 40℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.42g of sulfur residue.

[0084] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.87 g of elemental sulfur and 0.50 g of waste residue. The total amount of residue was reduced by 92.88%.

[0085] Example 10

[0086] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 300rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 2h. After the reaction, the pH of the solution is 0.8. After filtration, a manganese ion leaching solution containing 82.36g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.91g are obtained.

[0087] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 90.04%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0088] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.42g of sulfur residue.

[0089] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.88 g of elemental sulfur and 0.50 g of waste residue. The total residue amount was reduced by 92.65%.

[0090] Example 11

[0091] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 200g / L H2SO4 solution into it. Stir at 300rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 1h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.33g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.64g are obtained.

[0092] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 90.83%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0093] (3) Take 2g of acid leaching residue and 50mL of 160g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.12g of sulfur residue.

[0094] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. After dissolving the sulfur residue in 10 mL of toluene, 0.68 g of elemental sulfur and 0.39 g of waste residue were obtained by distillation. The total amount of residue was reduced by 94.47%.

[0095] Example 12

[0096] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 250g / L H2SO4 solution into it. Stir at 350rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.12g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.64g are obtained.

[0097] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 90.83%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0098] (3) Take 2g of acid leaching residue and 50mL of 40g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 2h. After filtration, obtain a filtrate containing lead ions and 1.61g of sulfur residue.

[0099] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 1.17 g of elemental sulfur and 0.39 g of waste residue. The total amount of residue was reduced by 94.50%.

[0100] Example 13

[0101] (1) Take 20g of zinc anode mud and 25g of thiourea and put them into a 250mL conical flask. Pour 100mL of 150g / L H2SO4 solution into it. Stir at 350rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.28g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.61g are obtained.

[0102] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and high-value-added elemental sulfur and manganese dioxide are obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate is 90.29%, and the purity is over 90%, which meets the national first-class MnO2 standard (ZBG13001-86).

[0103] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 0.5h. Filter to obtain filtrate containing lead ions and 1.61g of sulfur residue.

[0104] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. After dissolving the sulfur residue in 10 mL of toluene, 0.98 g of elemental sulfur and 0.56 g of waste residue were obtained by distillation. The total amount of residue was reduced by 92.09%.

[0105] Example 14

[0106] (1) Take 40g of zinc anode mud and 50g of thiourea and put them into a 250mL conical flask. Pour 200mL of 150g / L H2SO4 solution into it. Stir at 350rpm and the solid-liquid ratio is 200g / L. React at 60℃ for 3h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.22g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 11.26g are obtained.

[0107] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 89.91%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0108] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 1h and filter to obtain lead ion-containing filtrate and 1.45g of sulfur residue.

[0109] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. After dissolving the sulfur residue in 10 mL of toluene, it was distilled to obtain 0.89 g of elemental sulfur and 0.51 g of waste residue. The total amount of residue was reduced by 92.82%.

[0110] Example 15

[0111] (1) Take 60g of zinc anode mud and 75g of thiourea into a 500mL conical flask, pour in 240mL of 150g / L H2SO4 solution, stir at 350rpm, and the solid-liquid ratio is 250g / L. React at 60℃ for 4h. After the reaction, the pH of the solution is 1. After filtration, a manganese ion leaching solution containing 85.14g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 16.83g are obtained.

[0112] (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis was performed at the anode, and high-value-added elemental sulfur and manganese dioxide were obtained by electrolysis at the anode under the monitoring of the anode potential. The manganese recovery rate was 91.40%, and the purity was over 90%, which met the national first-class MnO2 standard (ZBG13001-86).

[0113] (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 1.5h. Filter to obtain filtrate containing lead ions and 1.37g of sulfur residue.

[0114] (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid was obtained by solidification. After oxidizing and roasting at 500 °C for 5 h, high-purity Pb3O4 product was obtained. The sulfur residue was dissolved in 10 mL of toluene and then distilled to obtain 0.83 g of elemental sulfur and 0.48 g of waste residue. The total residue amount was reduced by 94.32%.

[0115] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for the efficient recovery of manganese and lead from zinc anode mud using a reducing agent, characterized in that, Includes the following steps: (1) Take 20g of water-washed and dried zinc anode mud and 20g of thiourea into a 250mL conical flask, pour 100mL of 200g / L H2SO4 solution into it, control the stirring speed to 400rpm, the solid-liquid ratio to 200g / L, and react at 60℃ for 4h. After the reaction, the pH of the solution is 1.

2. After filtration, a manganese ion leaching solution containing 81.22g / L and an acid leaching residue containing lead sulfate and elemental sulfur of 5.11g are obtained. (2) Adjust the pH of the leachate to 0 and Mn using 50 g / L H2SO4. 2+ The concentration was diluted to 25 g / L, and the mixture was subjected to an experiment at 80 °C and a current density of 6 mA / cm². 2 Electrolysis is performed at the anode, and elemental sulfur and manganese dioxide are obtained by electrolysis sequentially at the anode by monitoring the anode potential. (3) Take 2g of acid leaching residue and 50mL of 120g / L ammonium acetate solution and place them in a 100mL conical flask. React at 60℃ for 3h. After filtration, obtain a filtrate containing lead ions and 1.13g of sulfur residue. (4) After adding excess 45 g / L oxalic acid solution to the filtrate in step (3) and reacting for 0.5 h, solid lead oxalate solid is obtained by solidification. After oxidizing and roasting it at 500 °C for 5 h, high-purity Pb3O4 product is obtained. After dissolving the sulfur residue in 10 mL of toluene, it is distilled to obtain 0.69 g of elemental sulfur and 0.39 g of waste residue.

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