A method for preparing a low-silverized lead-silver alloy anode material

Abstract

This invention discloses a method for preparing a low-silver-doped lead-silver alloy anode material. The method includes first smelting a lead-silver master alloy, adding melted silver to molten lead, and using electromagnetic and mechanical stirring to ensure uniform alloy composition. During casting and solidification, ultrasonic external field strengthening technology is employed to produce the lead-silver master alloy. Then, the lead-silver master alloy and rare earth modifier are added to the molten lead, along with a dispersant and antioxidant. The metal smelting temperature is controlled between 380℃ and 520℃, and the smelting time is 0.5 h. Electromagnetic and mechanical stirring techniques are used to ensure uniform alloy composition distribution. After casting and solidification, a blank for producing lead-silver alloy anode plates is finally obtained. This method is applied to the production of anode plates for zinc electrowinning.

Description

Technical Field

[0001] This invention patent belongs to the field of hydrometallurgical technology, specifically relating to a method for preparing a low-silver lead-silver alloy anode material. Background Technology

[0002] Hydrometallurgy has technological advantages such as low energy consumption, low pollution, low investment and low production cost, and has a large application scale in the metallurgical field, especially in the hydrometallurgical zinc smelting industry. More than 85% of the world's zinc production capacity uses hydrometallurgical zinc smelting. The mainstream process of hydrometallurgical zinc smelting is high-temperature roasting of zinc concentrate, leaching, purification and electrowinning.

[0003] Against the backdrop of the national strategic goals of "energy conservation and emission reduction" and "carbon peaking and carbon neutrality", metallurgical enterprises are focusing on improving "unit energy efficiency", reducing costs and increasing efficiency, and accelerating and increasing production. In order to increase production scale, they must improve the original processes and design production capacity. However, the complex source of zinc ore and low grade of zinc metallurgical enterprises lead to complex electrolyte composition and excessive impurity content, which puts increasing cost and environmental pressure on the electrowinning efficiency and production benefits of anode and cathode plates.

[0004] Currently, zinc electrowinning primarily uses high-silver binary alloy lead anode plates with a silver content of 0.7%–2.0%. While theoretically possessing high conductivity, practical applications suffer from problems such as poor corrosion resistance, silver segregation, and short service life due to impurities in the electrolyte and issues during electrocatalysis. Despite investing in high silver content to improve efficiency, companies have not achieved the desired overall efficiency benefits. Furthermore, in the past year, the prices of the main raw materials for zinc electrowinning electrodes—lead, silver, copper, tin, and aluminum—have continued to rise, especially silver and copper, which have repeatedly broken historical price records. This has invisibly increased the unit price of anode plates, resulting in significantly higher procurement costs for user companies and directly impacting their cost reduction and efficiency improvement efforts.

[0005] To meet the needs of industrial production, this paper proposes a method for preparing a lead-silver alloy anode material with low silver content. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for preparing a low-silver alloy anode material with low silver content and excellent electrodeposition performance.

[0007] To achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution: a method for preparing a low-silver-doped lead-silver alloy anode material, specifically including the following steps: S1. Melting lead-silver master alloy. After melting silver (accounting for 5% of the total melt), it is added to the molten lead. The melting temperature of the two metals is controlled at 450℃~965℃ for 1 hour. Electromagnetic strengthening + mechanical strengthening stirring is used to ensure uniform alloy composition. Ultrasonic external field strengthening technology is used during casting and solidification to ensure the refinement of alloy material grains and the separation of impurities, thus producing lead-silver master alloy. As a preferred embodiment of the present invention, the silver content in the lead-silver master alloy in S1 is 5%; As a preferred embodiment of the present invention, the antioxidant in S1 is carbon powder; S2. After the lead-silver master alloy in the melting furnace is fully melted, ultrasonic external field strengthening technology is used during the casting and solidification process to avoid segregation, ensure uniform alloy composition, and refine grain size. As a preferred embodiment of the present invention, the ultrasonic device in S2 has a power of 2000W; S3. Prepare the anode plate blank. Add a lead-silver master alloy (with silver content accounting for 0.1-0.3% of the total melt) and a rare earth modifier to the molten lead. Add a dispersant and an antioxidant. Control the metal melting temperature between 380℃ and 520℃, and the melting time is 0.5 hours. Utilize electromagnetic and mechanical stirring techniques to ensure uniform alloy composition distribution. After casting and solidification, the blank for making the lead-silver alloy anode plate is finally obtained. This method is applied to the production of anode plates for zinc electrowinning.

[0008] As a preferred embodiment of the present invention, the alloy components added to the molten lead in S3 are: lead-silver master alloy (wherein the silver content accounts for 0.1~0.3% of the total melt), rare earth modifier 0.05%, and antioxidant.

[0009] As a preferred embodiment of the present invention, the lead-silver master alloy in S3 contains 5% silver and 95% lead.

[0010] Based on the above technical solution, the present invention provides a low-silver lead-silver alloy, which is prepared by a method for preparing a low-silver lead-silver alloy anode material.

[0011] Based on the above technical solution, the present invention provides an application of a low-silver lead-silver alloy in the production of zinc electrowinning anode plates.

[0012] The beneficial effects of this invention are: The novel low-silver, high-efficiency alloy anode material prepared by the method of this invention reduces the silver content of the anode through key alloy element control technology, significantly reducing the production cost of the anode plate. Furthermore, its corrosion resistance, alloy element uniformity, and overall electrochemical performance are superior to traditional high-silver alloy anodes. Zinc electrowinning experiments have shown that the resistivity, oxygen evolution overpotential, and final energy consumption per ton of zinc produced by the method of this invention are at the same level as ordinary high-silver anodes, indicating that the novel low-silver anode can effectively reduce production costs while achieving the same performance. Moreover, compared to ordinary high-silver anodes, the novel low-silver anode exhibits a 10.78% lower corrosion rate and a longer service life. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Those skilled in the art can obtain other drawings based on these drawings without creative effort. Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example 1

[0015] like Figure 1 As shown in this embodiment, the existing technology has the following problems: The inventors have found that the high silver alloy lead anode plates currently mainly used in zinc electrolysis have high theoretical electrical efficiency, but they have problems such as poor corrosion resistance, silver segregation, and short service life during use. The overall electrical efficiency of enterprises is low after use, and due to the rising prices of precious metals such as gold and silver this year, the cost of use is too high. These factors are not conducive to the energy saving and efficiency improvement of enterprises.

[0016] Therefore, the inventors have provided a method for preparing a low-silver alloy anode material with low silver content and excellent electrodeposition performance.

[0017] To achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution: a method for preparing a low-silver-doped lead-silver alloy anode material, specifically including the following steps: S1. Melting lead-silver master alloy. After melting silver (accounting for 5% of the total melt), it is added to the molten lead. The melting temperature of the two metals is controlled at 450℃~965℃ for 1 hour. Electromagnetic strengthening + mechanical strengthening stirring is used to ensure uniform alloy composition. Ultrasonic external field strengthening technology is used during casting and solidification to ensure the refinement of alloy material grains and the separation of impurities, thus producing lead-silver master alloy. In this embodiment, the silver component in the lead-silver master alloy in S1 is 5%; In this embodiment, the antioxidant in S1 is carbon powder; S2. After the lead-silver master alloy in the melting furnace is fully melted, ultrasonic external field strengthening technology is used during the casting and solidification process to avoid segregation, ensure uniform alloy composition, and refine grain size. In this embodiment, the ultrasonic device in S2 has a power of 2000 W; S3. Prepare the anode plate blank. Add a lead-silver master alloy (with silver content accounting for 0.1-0.3% of the total melt) and a rare earth modifier to the molten lead. Add a dispersant and an antioxidant. Control the metal melting temperature between 380℃ and 520℃, and the melting time is 0.5 hours. Utilize electromagnetic and mechanical stirring techniques to ensure uniform alloy composition distribution. After casting and solidification, the blank for making the lead-silver alloy anode plate is finally obtained. This method is applied to the production of anode plates for zinc electrowinning.

[0018] In this embodiment, the alloy components added to the molten lead in S3 are: lead-silver master alloy (wherein the silver content accounts for 0.1~0.3% of the total melt), rare earth modifier 0.05%, and antioxidant.

[0019] In this embodiment, the lead-silver master alloy in S3 contains 5% silver and 95% lead.

[0020] Based on the above technical solution, the present invention provides a low-silver lead-silver alloy, which is prepared by a method for preparing a low-silver lead-silver alloy anode material.

[0021] Based on the above technical solution, the present invention provides an application of a low-silver lead-silver alloy in the production of zinc electrowinning anode plates. Example 2

[0022] Based on the above embodiments, the inventors conducted the following comparative experiments: 1. First, melt the lead-silver intermediate alloy. Add 5% silver, dispersant, and antioxidant (carbon powder) to the molten lead. Use electromagnetic strengthening + mechanical strengthening stirring technology to ensure uniform alloy composition. Control the temperature at 550℃~600℃ and the melting time is 1 hour. After the lead-silver master alloy is melted in the melting furnace, ultrasonic external field strengthening technology (ultrasonic equipment power 2000W) is used during the casting and solidification process to avoid segregation, ensure uniform alloy composition, and refine grain size. Then, 5% lead-silver master alloy (containing 5% silver), 1% lead-calcium alloy (containing 3% calcium), 1% lead-strontium alloy (containing 5% strontium) and 1% rare earth modifier were added to the molten lead. Dispersant and antioxidant were added, and advanced electromagnetic strengthening and mechanical strengthening stirring technology was used to ensure uniform alloy composition. The temperature was controlled at 450℃~500℃ and the melting time was 1 hour. Finally, a low-silver lead-silver alloy was obtained as the raw material for making anode plates. 2. The inventors obtained a low-silver lead-silver alloy anode plate using the anode plate raw materials described in the above technical solution, and set the following parameters: sulfuric acid concentration of 160 g / L, electrolyte zinc ion concentration of 50 g / L, and current density of 500 A / m. 2 The cell voltage was controlled at an electrowinning environment of 3.2-3.5 V. Electrochemical performance was compared with that of ordinary high-silver anode plates in existing technologies during a 36-hour zinc electrowinning experiment. Details are as follows: Comparison of performance between low-silver lead-silver alloy anodes and ordinary high-silver alloy anodes. Anode type Silver content Resistivity (Ω·cm) <![CDATA[Corrosion rate (g / m 2. h)]]> Oxygen evolution overpotential (mV) <![CDATA[Power consumption (kW·h / t Zn )]]> New low-silver anode 0.85% <![CDATA[20.85×10 -6 ]]> 0.761 830 3160 Ordinary high silver anode 2.0% <![CDATA[19.55×10 -6 ]]> 0.679 820 3120 Therefore, it was concluded that, through zinc electrowinning experiments, the silver content of the novel low-silver anode prepared using the method of this invention was reduced by 57.5% compared with that of ordinary high-silver anodes. Moreover, the anode resistivity, oxygen evolution overpotential, and final electricity consumption per ton of zinc produced were not significantly different from those of ordinary high-silver anodes, and were close to the same level. This indicates that the silver content of the novel low-silver anode is significantly reduced compared with that of ordinary high-silver anodes, which can effectively reduce production costs while obtaining the same performance. Furthermore, compared with ordinary high-silver anodes, the corrosion rate of the novel low-silver anode is reduced by 10.78%, resulting in a longer service life. Furthermore, practical application has shown that the low-silver, high-efficiency, energy-saving anode plate reduces silver content by more than 30% through rare earth addition technology, resulting in a 25% reduction in production costs, a 10%-20% reduction in electricity consumption per ton of zinc, and an extended service life of 3-6 months. The long-lasting corrosion-resistant anode utilizes a multi-component composite matrix and a nano-ceramic reinforcing layer, combined with corrosion-resistant slow-release additives. In highly corrosive electrolytes containing Cl⁻ (>500mg / L) and F⁻ (>100mg / L), the annual corrosion rate is ≤5% (traditional >10%), with a service life of 12-18 months. Through optimization of oxygen evolution active sites, the overpotential is reduced by 50mV, current efficiency is increased to 97.5%, and energy savings are 10%-15%. The anode mud forms a dense layered structure, increasing impurity capture rate by 40%, making it suitable for zinc, copper, nickel, and other smelting processes, applicable to high-acid complex electrolytes, and reducing annual maintenance costs for enterprises by more than 25%.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for producing a low-silvered lead-silver alloy anode material, characterized by, Specifically comprising the following steps: S1, smelting lead silver intermediate alloy. After melting silver (5% of the total melting amount), add it to the melted lead liquid, control the smelting temperature of the two metals at 450-965℃, and the time is 1h; electromagnetic strengthening + mechanical strengthening stirring is used to ensure the uniformity of the alloy composition, ultrasonic field strengthening technology is used in the casting and solidification process to ensure grain refinement and impurity separation of the alloy material, and lead silver intermediate alloy is prepared; S2, after the lead silver intermediate alloy in the smelting furnace is fully smelted, ultrasonic field strengthening technology is used in the casting and solidification process to avoid segregation and ensure uniform alloy composition, and at the same time, grain refinement is achieved; S3, the anode plate blank is prepared. Lead silver intermediate alloy (silver content accounts for 0.1-0.3% of the total melting amount) and rare earth modifier are added to the melted lead liquid, dispersant and antioxidant are added, the metal smelting temperature is controlled at 380-520℃, the smelting time is 0.5h, and under the action of electromagnetic strengthening + mechanical strengthening stirring technology, the uniform distribution of alloy composition is ensured, and after casting and solidification, the blank for preparing lead silver alloy anode plate is finally obtained. The method is applied to the production of zinc electrodeposition anode plate.

2. A process for the production of a low silvered lead-silver anode material according to claim 1, characterized in that: The silver component in the lead silver intermediate alloy in S1 is 5%.

3. The method for preparing a low-silver lead-silver alloy anode material according to claim 1, characterized in that: The antioxidant in S1 is carbon powder.

4. The method for preparing a low-silver lead-silver alloy anode material according to claim 1, characterized in that: The power of the ultrasonic equipment in S2 is 2000W.

5. The method for preparing a low-silver lead-silver alloy anode material according to claim 1, characterized in that: The alloy components added to the melted lead liquid in S3 are: lead silver intermediate alloy (silver content accounts for 0.1-0.3% of the total melting amount), rare earth modifier 0.05% and antioxidant.

6. The method for preparing a low-silver lead-silver alloy anode material according to claim 1, characterized in that: The lead silver intermediate alloy in S3 contains 5% silver and 95% lead.

7. A low-silver lead silver alloy according to any one of claims 1 to 6, prepared by the method of claim 1.

8. The use of a low-silver lead silver alloy according to claim 7 in the production of zinc electrodeposition anode plates.

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