Sandwich structured foam metal-lead alloy composite material and preparation and application thereof

Abstract

The present application relates to a kind of lead anode materials, specifically relates to a sandwich structure foam metal lead alloy composite material, including foam aluminum and the lead-containing alloy coated on its surface and filled in its pore structure, the surface of the pore skeleton of the foam aluminum and radial direction contain irregular nonlinear hole.The present application also includes the preparation method of the material, the material prepared by the preparation method of the present application has excellent performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of materials, in particular to the field of Pb anode materials. BACKGROUND

[0002] The extraction methods of heavy metals such as copper, zinc, manganese, nickel and cobalt can be roughly divided into pyrometallurgy and hydrometallurgy. Due to the advantages of high comprehensive recovery rate of valuable metals, small degree of air pollution, strong adaptability to low-grade ores and easy automation in production process, the proportion of hydrometallurgy in the mining of these non-ferrous metals gradually increases. For example, nearly 20% of the world's copper production capacity, more than 85% of the world's zinc production capacity, most of the world's manganese production capacity and almost 100% of the world's high-purity nickel and cobalt production capacity are extracted by hydrometallurgy.

[0003] In the hydrometallurgical process, electrodeposition is a crucial process, and lead alloy plates are usually used as insoluble anodes. However, the traditional lead alloy plate anode has the disadvantages of high density, poor mechanical properties, low electrical conductivity and high oxygen evolution overpotential, which leads to difficult anode operation process and high power consumption. Researchers at home and abroad have actively explored and made considerable progress. Among them, composite aluminum-based anodes have been increasingly favored in recent years due to their low density, low cost, good electrical conductivity and no harm to electrolyte. For example, compared with traditional Pb-Ag plate anodes, plate Al / Pb-Ag alloy anodes have lower corrosion rate and oxygen evolution overpotential; however, how to effectively ensure the good bonding between the plate Al substrate and the outer layer of lead alloy is still the key to whether the anode can enter the actual production stage. Aluminum-based coated anodes (Al / α-PbO2-β-PbO2, Al / Pb-Co3O4, Al / Pb-0.6% Sn-WC, etc.) mainly have two problems. On the one hand, the existing preparation process is complicated due to the presence of many coatings, which limits the practicality and operability; on the other hand, the surface treatment technology of the metal substrate is not mature enough, resulting in poor bonding force between the surface active layer and the substrate. Under the severe scouring of oxygen, the surface active layer is easy to fall off, ultimately causing the anode to fail and increasing the cost. SUMMARY

[0004] In view of the problems existing in the prior art Pb anode, the first object of the present application is to provide a sandwich structure foam metal@lead alloy composite material, aiming to provide a new anode material with tight interface bonding and excellent electrical conductivity and creep resistance.

[0005] The second object of the present application is to provide a preparation method of a sandwich structure foam metal@lead alloy composite material, aiming to prepare the special sandwich structure foam metal@lead alloy composite material.

[0006] The third object of the present application is to provide the sandwich structure foam metal-lead alloy composite material as anode.

[0007] The sandwich structure foam metal-lead alloy composite material comprises foam metal and lead-containing alloy coated on the surface and filled in the pore structure of the foam metal, wherein the surface and radial direction of the pore skeleton of the foam metal contain irregular non-linear pores.

[0008] The present application provides the sandwich structure foam metal-lead alloy composite material for the first time, which has excellent interface bonding stability between the foam metal base and the lead-containing alloy, and also has excellent electrical conductivity and anti-creep performance, and can exhibit excellent performance when used as an anode.

[0009] Preferably, the foam metal has interconnected pores with a pore size of 2-3 mm and a porosity of 70-90%.

[0010] The foam metal is, for example, foam aluminum, foam copper, etc. The thickness of the foam metal is not particularly limited, and can be, for example, 6-10 mm.

[0011] In the present application, the lead-containing alloy is any alloy material containing lead, which can be, for example, an alloy formed by lead metal and at least one of Ag, Ca, Sr, Nd, and Sn; and can further be at least one of Pb-Ag alloy, Pb-Ag-Ca-Sr alloy, Pb-Ag-Nd alloy, and Pb-Ca-Sn alloy.

[0012] In the present application, the lead-containing alloy coats the upper and lower surfaces of the foam metal and sufficiently fills the pore structure of the foam metal. For example, the lead-containing alloy fills more than 90% of the pore structure of the foam metal, preferably close to 100%.

[0013] In the present application, the thickness of the lead-containing alloy is greater than that of the foam metal, and the difference is preferably 2-6 mm. Preferably, the distance between the upper surface of the lead-containing alloy and the upper surface of the porous metal is 1-3 mm, and the distance between the lower surface of the lead-containing alloy and the lower surface of the porous metal is 1-3 mm.

[0014] The present application also provides a preparation method of the sandwich structure foam metal-lead alloy composite material, which comprises subjecting the foam metal to a first-stage treatment in a vapor containing nitric acid, a second-stage treatment in an alkali solution, and then water washing and drying to obtain a surface-modified foam metal.

[0015] The modified foam metal is subjected to infiltration treatment with a lead-containing alloy melt to coat and sufficiently fill the pore structure of the modified foam metal, thereby obtaining the sandwich structure foam metal-lead alloy composite material.

[0016] The application first proposes the idea of preparing a sandwich structure of a foam metal-lead alloy material based on a percolation method in the industry. However, previous studies have found that it is difficult to successfully prepare a material with stable interface bonding and excellent electrical conductivity due to the difficulty in percolation coating and filling of the pore structure caused by the unsatisfactory interface adaptability of the lead-containing alloy and the foam metal. In view of the preparation difficulty of the composite material, the application finds that the nitric acid vapor is innovatively used for gas-solid modification treatment of the foam metal, and further combined with the subsequent solid-liquid treatment idea in the alkali solution, so as to realize the cooperation, construct irregular and nonlinear slits on the surface and radial direction of the foam metal, and facilitate the chemical modification of the surface of the skeleton, so as to improve the interface adaptability between the lead-containing alloy and the skeleton, guide the effective percolation filling and complete coating of the lead-containing alloy to the pore structure of the foam metal, and improve the interface bonding stability, electrical conductivity and creep resistance of the prepared material, and further improve the anode performance.

[0017] Preferably, the first stage of the treatment process further comprises an auxiliary gas, and the pressure in the treatment process is greater than 1 atm (atmospheric pressure), preferably 1.5-5 atm. The pressure can be built by the auxiliary gas pressurization method to build the pressurized system. Studies have found that under this preferred process, it is helpful to further reduce the potential and cell voltage, and in addition, it is also helpful to improve the service life.

[0018] In the application, the auxiliary gas is nitrogen or an inert gas such as argon. The application also found that under the preferred first stage of the treatment process, it is helpful to further improve the interface adaptability of the alloy melt and the skeleton, and more conducive to improving the percolation filling effect.

[0019] In the application, the temperature of the first stage of the treatment process is above 80℃, and considering the treatment cost, it can be further 80-100℃.

[0020] Preferably, the time of the first stage of the treatment process is 10-25 min, further preferably 10-15 min, and more preferably 12-13 min.

[0021] In the application, after the first stage of the treatment, the product can be directly or washed in water and then placed in an alkali solution for the second stage of the treatment. The solute in the alkali solution is at least one of ammonia, alkali metal hydroxide and alkali metal carbonate.

[0022] The concentration of the solute in the alkali solution is not particularly required, for example, it can be 5-50wt%.

[0023] In the application, after the second stage of the treatment, the treated product is washed in water and dried.

[0024] In a preferred embodiment of the present application, the second segment of the modified foam metal is subjected to electroless plating of a lead alloy material, such as a lead-tin alloy. This helps to further reduce the potential and the cell voltage, and also helps to improve the service life.

[0025] The surface plating is preferably carried out by electroless plating or electroplating.

[0026] Preferably, the plating solution used in the surface plating stage is a fluoborate plating solution, which is an aqueous solution comprising 10-50 g / L of lead fluoborate, 20-50 g / L of stannous fluoborate, 200-400 g / L of free fluoboric acid, 0.5-1.5 g / L of phenothalin, and 1-4 g / L of octylphenol polyoxyethylene ether.

[0027] Preferably, the plating stage is carried out at a temperature of 50-80 °C and at a current density of 3-8 A / dm 3 .

[0028] Preferably, the plating time is not particularly limited, and can be, for example, 5 min or more, and further can be 10-20 min.

[0029] In the present application, the modified foam metal is subjected to infiltration treatment with a lead-containing alloy.

[0030] In the present application, the lead-containing alloy can be any alloy that contains lead and can form an alloy, as known in the art. For example, it can be at least one of a Pb-Ag alloy, a Pb-Ag-Ca-Sr alloy, a Pb-Ag-Nd alloy, and a Pb-Ca-Sn alloy.

[0031] In the present application, the infiltration treatment can be carried out using existing equipment. In order to produce the composite material of the present application, a protrusion for supporting the foam metal and forming a gap between the foam metal and the lower punch is preferably provided on the upper surface of the lower punch (and the opposite surface of the lead alloy) of the existing infiltration treatment equipment.

[0032] In the present application, the temperature during the infiltration stage is such that the lead-containing alloy is maintained in a molten state, for example, at a temperature of 350 °C or more.

[0033] The present application also includes the sandwich-structured foam metal@lead alloy composite material produced by the production method.

[0034] The present application also provides the use of the sandwich-structured foam metal@lead alloy composite material as an anode. In the present application, the sandwich-structured foam metal@lead alloy composite material can be used as an anode based on existing principles and methods. For example, it can be used as a composite lead anode for a wet metallurgical electrodeposition process based on existing means.

[0035] Advantages

[0036] 1. The sandwich structure of the foam metal lead alloy composite material is provided for the first time, the foam metal base and the lead alloy have excellent interface bonding stability, and also have excellent electric conductivity and anti-creep performance. The composite material has excellent electric conductivity and mechanical strength, and has low oxygen evolution overpotential, so that the anode life can be improved when the composite material is used as an anode, and the quality of the cathode product can be improved.

[0037] 2. In view of the material preparation problems of the material, the sandwich structure of the foam metal lead alloy composite material is successfully prepared by using nitric acid vapor gas-solid one-stage modification, two-stage modification of lye, and further cooperating with surface plating of lead-tin alloy and infiltration treatment process, so that the interface bonding capacity, alloy filling effect, electric conductivity and anti-creep performance can be improved.

[0038] 3. In the present application, the first stage modification treatment is further assisted by gas pressurization, or the lead alloy is pre-prepared on the modified porous material, so that the synergistic effect of the process can be further improved.

[0039] 4. In the present application, the raw material cost of the composite anode is low, and the composite anode can be integrally formed, and the preparation process is simple. In addition, the prepared material has good interface bonding capacity and integral forming advantage, and can exhibit excellent electric conductivity and anti-creep performance. When the prepared material is used as an anode, the cell voltage and short circuit frequency can be reduced, and the energy consumption of the electrodeposition process can be saved. BRIEF DESCRIPTION OF DRAWINGS

[0040] ATTACHMENT Figure 1 The device for preparing the foam metal base lead alloy anode is shown in the figure:

[0041] 1 - briquetting; 2 - upper punch; 3 - lead alloy; 4 - foam metal; 5 - lower punch;

[0042] 6 - die cushion; 7 - negative mold; 8 - heating furnace; 9 - thermocouple; 10 - temperature controller.

[0043] ATTACHMENT Figure 2 The foam metal base lead alloy anode structure is shown in the figure, and the cross-sectional view is shown.

[0044] ATTACHMENT Figure 3 The lower punch (5) is shown in the figure, and there are two rectangular protrusions with a height of 2 mm above the lower punch (5). DETAILED DESCRIPTION

[0045] The foam metal used at the beginning of the present application, such as foam aluminum and foam copper, can be any commercial product in the industry, for example, it can be a product with interconnected pores, and the thickness is 6-8 mm, the pore size is 2-3 mm, and the porosity is 70-90%.

[0046] The steps of the foamed metal of the present application are, for example, as follows, taking foamed aluminum as an example:

[0047] Step 1:

[0048] The foamed aluminum can be subjected to oil removal treatment based on known means, and is subjected to first-stage modification treatment in nitric acid vapor at a temperature of 80-100℃ (the foamed aluminum and concentrated nitric acid can be placed in the same container, wherein the foamed aluminum is arranged above the concentrated nitric acid, and then the concentrated nitric acid is heated and volatilized, and the foamed aluminum is subjected to gas-solid treatment in the volatilized nitric acid vapor), and is subjected to second-stage modification treatment in an alkali solution (such as a sodium hydroxide solution) after direct or selective water washing, and is then cleaned with deionized water, dried, and modified foamed aluminum is prepared.

[0049] In a preferred embodiment of the present application, the surface of the foamed metal subjected to the second-stage treatment is subjected to chemical plating of a lead alloy material, and the alloy material is, for example, a lead-tin alloy;

[0050] Preferably, the surface plating is performed by chemical plating or electroplating.

[0051] Preferably, the plating solution used in the surface plating stage is a fluoborate plating solution, which is an aqueous solution including 10-50 g / L lead fluoborate, 20-50 g / L stannous fluoborate, 200-400 g / L free fluoboric acid, 0.5-1.5 g / L phenolphthalein, and 1-4 g / L octylphenol polyoxyethylene ether. In the following cases, unless otherwise specified, the plating solution used is 30 g / L lead fluoborate, 40 g / L stannous fluoborate, 300 g / L free fluoboric acid, 1 g / L phenolphthalein, and 1.5 g / L octylphenol polyoxyethylene ether. Electroplating is performed at a temperature of 70℃ and a current density of 5 A / dm 3 for 15 min.

[0052] Step 2: Infiltration treatment

[0053] The modified foamed aluminum is subjected to infiltration treatment using a lead alloy melt.

[0054] The infiltration treatment can be performed using an infiltration device Figure 1 . The infiltration device of the present application differs from existing infiltration devices mainly in that the lower punch upper surface is provided with protrusions (as shown in Figure 3 ) that support the foamed aluminum and have a gap with the lower punch surface. The protrusions can be provided with a lower punch edge, and the number thereof is not particularly limited as long as the foamed aluminum can be supported. In the present case, the protrusions can be two parallel long strip-shaped protrusions.

[0055] In the present application, the lower punch, foamed metal, lead alloy, and upper punch can be sequentially and vertically added to a mold based on existing infiltration operation means, the mold is placed in a heating furnace, the briquette is placed on the upper punch, and a thermocouple is connected.

[0056] Turn on the temperature controller and set the temperature rising program, and rise the temperature to 360-390℃ at a speed of 5-10℃ / min, keep the temperature for 10-20min, and then cool down to 80-100℃ naturally to demould.

[0057] In the present application, the coating defects formed at the contact position with the protrusions can be repaired by additional coating or discarded by cutting.

[0058] The following is a typical embodiment of the present application, for example:

[0059] Example 1 Foam Al / Pb-Ag Alloy Anode

[0060] The preparation method comprises the following steps:

[0061] First step: oil removal treatment

[0062] Put the foam aluminum with a thickness of 8mm and a pore size of 3-4mm into the prepared mixed sodium salt solution (20g / L sodium hydroxide, 4g / L sodium silicate, 10g / L sodium carbonate, 20g / L sodium phosphate), soak for 3min to remove the oil stains on the surface of the foam aluminum; then put the foam aluminum into anhydrous ethanol and ultrasonic for 40min to wash and remove the oil; finally, put the foam metal into 15% dilute hydrochloric acid for 30s, rinse with distilled water, and dry for use.

[0063] Second step: modification treatment

[0064] Put the foam aluminum substrate treated in the first step into nitric acid vapor at a temperature of 80-85℃ (the weight ratio of foam aluminum to nitric acid is 5:1) and perform the first-stage modification treatment t1 (12-13min) under normal pressure, then wash with water, and then put it into 30wt% sodium hydroxide solution (aqueous solution) for the second-stage modification treatment (the treatment temperature is room temperature), the second-stage modification treatment time t2 is 5min, then rinse with deionized water and dry; obtain the modified foam aluminum.

[0065] Third step: loading

[0066] Put the lower punch (the contact surface with the foam aluminum contains protrusions, and the protrusion height is 2mm), foam aluminum (modified foam aluminum in the second step), lead-silver alloy (0.75wt.% Ag, the balance is Pb), and upper punch into the mold in sequence and vertically, put the mold into the heating furnace, then put the briquette on the upper punch, and connect the thermocouple;

[0067] Fourth step: temperature rising and infiltration

[0068] The temperature controller was turned on and set to a temperature rising program with a temperature rising rate of 10 ℃ / min to 380 ℃, so that the lead-silver alloy was liquefied and infiltrated into the modified foam aluminum, and the infiltration time was 15 min, then the foam aluminum was naturally cooled to 100 ℃ in the furnace, and the protruding part was repaired by coating or cutting the part of the coating defect caused by the protrusion, thereby obtaining the sandwich structure composite material (labeled as Al / Pb-0.75wt.%Ag alloy anode).

[0069] Cell voltage test conditions: 40℃ water bath heating, anode: prepared composite anode, examples 1-5: simulated industrial zinc smelting electrolyte (55g / L ZnSO4, 160g / L H2SO4 aqueous solution), cathode: aluminum plate; example 6: simulated industrial copper smelting electrolyte (44g / L CuSO4, 160g / L H2SO4 aqueous solution), cathode: stainless steel plate.

[0070] Anode potential test conditions: 38℃ water bath heating, three-electrode system, anode: prepared sandwich structure composite anode, cathode: platinum electrode, reference electrode: saturated potassium sulfate, electrolyte: 160g / L H2SO4, current density: 500A / m 2 .

[0071] In the present application, the service life can be determined based on known methods, for example, in the present application, the prepared anode is used as the anode, the Ti plate is used as the cathode plate, the polarization is carried out in the electrolyte of 160g / L sulfuric acid solution at a temperature of 40℃ and a current density of 4A / cm 2 , and the service life is determined when the polarization potential increases sharply.

[0072] Compared with the existing industrial Pb-0.75wt.%Ag alloy anode for zinc electrodeposition, the prepared foam Al / Pb-0.75wt.%Ag alloy anode in the present example has higher corrosion resistance, and under the premise of the same anode volume, the amount of Ag in the anode can be reduced by about 28%; the anode potential is 1.33V, which is reduced by 56mV; the cell voltage is 3.02V, which is reduced by 80mV; and the service life is prolonged by 40%.

[0073] Example 2:

[0074] Compared with example 1, the only difference is that in step 1, Ar is also used for pressurization treatment in the first-stage modification process, and the pressurization pressure is 2atm.

[0075] The method of example 1 is used for testing, and the results are as follows: anode potential 1.32V, cell voltage 2.98V, which is reduced by 46mV compared with the anode prepared in example 1, and the service life is increased by 13% compared with the anode of example 1.

[0076] Example 3:

[0077] The difference between this example and Example 2 is that after the second stage of the second step, the modified foam aluminum is further coated with a Pb-Sn alloy film by electroless plating. The plating solution is 30 g / L lead fluoroborate, 40 g / L stannous fluoroborate, 300 g / L free fluoroboric acid, 1 g / L phenolphthalein, and 1.5 g / L octylphenol polyoxyethylene ether. The plating is carried out at a temperature of 70 °C and a current density of 5 A / dm 3 for 15 min. The modified foam aluminum is then subjected to the subsequent steps of Example 1.

[0078] The performance of the foam Al / Pb-Ag-Ca-Sr alloy anode is tested according to the method of Example 1, and the results are as follows: anode potential, 1.30 V; cell voltage, 2.91 V; and service life, 35% longer than that of the anode prepared in Example 1.

[0079] Example 4: Foam Al / Pb-Ag-Ca-Sr alloy anode

[0080] The difference between this example and Example 3 is that the alloy material for infiltration in the third step is changed to a lead-silver-calcium-strontium alloy (0.25 wt.% Ag, 0.08-0.12 wt.% Ca and Sr in total, and the balance Pb), and the temperature of the infiltration stage in step 4 is 390 °C. The other operations and parameters are the same as in Example 1.

[0081] The performance of the foam Al / Pb-Ag-Ca-Sr alloy anode is tested according to the method of Example 1, and the results are as follows: the foam Al / Pb-Ag-Ca-Sr alloy anode has a higher stability than the Al / Pb-Ag-Ca-Sr alloy anode currently used in industrial zinc electrowinning, and the anode potential and anode potential are 1.28 V and 2.82 V, respectively, which are 40 mV and 68 mV lower than those of the current anode.

[0082] Example 5: Foam Al / Pb-Ag-Nd alloy anode

[0083] The difference between this example and Example 3 is that the alloy material for infiltration in the third step is changed to a lead-silver-neodymium alloy (0.6 wt.% Ag, 0.1 wt.% Nd, and the balance Pb).

[0084] The performance of the foam Al / Pb-Ag-Nd alloy anode is tested according to the method of Example 1, and the results are as follows: the foam Al / Pb-Ag-Nd alloy anode prepared in this example has an anode potential that is 50 mV lower than that of the lead-silver-neodymium alloy (0.6 wt.% Ag, 0.1 wt.% Nd, and the balance Pb) anode currently used in industrial zinc electrowinning, and the mass of the former is about 30% lower than that of the latter.

[0085] Example 6: Foam Cu / Pb-Ca-Sn alloy anode

[0086] The difference between the example 3 and the example 1 is that the foamed metal in the step 1 is foamed copper (thickness of 8mm, pore size of 2mm), the alloy material needing to be infiltrated in the third step is changed to lead-calcium-tin alloy (0.07wt.% Ca, 1.25wt.% Sn, and the balance of Pb), and the temperature of the infiltration in the step 4 stage is 390℃.

[0087] The foamed Cu / Pb-Ca-Sn alloy anode prepared in the example 1 has an anode potential of about 100mV lower and a cell voltage of about 40mV lower than the current industrial Pb-Ca-Sn alloy anode (0.07wt.% Ca, 1.25wt.% Sn, and the balance of Pb) for copper electrowinning. In addition, the anode has a foamed copper framework, and the copper electrolyte is not contaminated even after long-term service.

[0088] The scheme has simpler device, convenient operation, easy demolding, higher infiltration degree of the obtained anode, lower oxygen evolution overpotential, light weight, high mechanical strength, and low cost.

[0089] Example 7

[0090] The difference between the example 7 and the example 1 is that the time of t1 is 20-21min. Other operations and parameters are the same as those in the example 1.

[0091] The anode prepared by the method of the example 1 is tested, and the anode potential is 1.29V, the cell voltage is 3.00V, and the service life is 5% lower than that of the anode in the example 1.

[0092] It can be known from the examples 1 and 7 that the gas-solid treatment method in the example 1 and the combined control of the treatment time can further improve the performance of the material.

[0093] Comparative Example 1

[0094] The difference between the example 1 and the comparative example 1 is that the first modified treatment process does not use the gas-solid treatment, but uses the liquid-solid treatment idea. For example, in the step 2, the foamed aluminum substrate treated in the first step is immersed in a 68wt% nitric acid solution for 30min, and other operations and parameters are the same as those in the example 1.

[0095] The anode prepared by the method of the example 1 is tested, and the anode potential is 1.35V, the cell voltage is 3.05V, the conductivity is reduced by 20%, and the service life is shortened by 25% compared with the example 1.

[0096] Comparative Example 2

[0097] The difference between the example 1 and the comparative example 2 is that the one-step forming is not used, that is, the lower surface does not contain the protrusions, and then the lower cladding layer is formed by coating (the thickness of the alloy layer coated on the upper surface and the lower surface of the anode is the same as that in the example 1). Other operations and parameters are the same as those in the example 1.

[0098] The prepared anode was tested using the method of Example 1, with an anode potential of 1.34 V and a cell voltage of 3.03 V, but with a 40% reduction in anode life compared to the anode of Example 1.

Claims

1. A sandwich structured foam metal-lead alloy composite, characterized by, The sandwich structure foam metal-lead alloy composite material comprises a foam aluminum and a lead-containing alloy coated on the surface of the foam aluminum and filled in the pore structure of the foam aluminum, wherein the surface and radial direction of the pore skeleton of the foam aluminum contain irregular non-linear pores. The preparation method of the sandwich structure foam metal-lead alloy composite material comprises the following steps: first treating the foam metal in a steam containing nitric acid, then treating the foam metal in an alkali solution, and then washing the foam metal with water and drying the foam metal to obtain a surface modified foam metal. The modified foam metal is subjected to a flow treatment by using a lead-containing alloy melt to coat the modified foam metal and sufficiently fill the pore structure of the modified foam metal, so as to obtain the sandwich structure foam metal-lead alloy composite material. The upper surface of the lower punch of the flow treatment equipment is provided with protrusions for supporting the foam metal and forming a gap between the foam metal and the lower punch.

2. The sandwich structured foam metal-lead alloy composite of claim 1, wherein The foam metal has interconnected pores, and the pore diameter is 2-3 mm and the porosity is 70-90%.

3. The sandwich structured foam metal-lead alloy composite of claim 2, wherein the metal is selected from the group consisting of aluminum, copper, magnesium, zinc, titanium, nickel, cobalt, iron, and alloys thereof. The foam aluminum can be replaced by a foam copper.

4. The sandwich structured foam metal-lead alloy composite of claim 1, wherein the metal is selected from the group consisting of aluminum, copper, magnesium, zinc, titanium, nickel, cobalt, iron, and alloys thereof. The lead-containing alloy coats the upper surface and the lower surface of the foam metal and sufficiently fills the pore structure of the foam metal.

5. The sandwich structured foam metal-lead alloy composite of claim 1, wherein the metal is selected from the group consisting of aluminum, copper, magnesium, zinc, titanium, nickel, cobalt, iron, and alloys thereof. The lead-containing alloy fills more than 90% of the pore structure of the foam metal.

6. A method of producing the sandwich structured foam metal-lead alloy composite material according to any one of claims 1 to 5, characterized by, The preparation method of the sandwich structure foam metal-lead alloy composite material comprises the following steps: first treating the foam metal in a steam containing nitric acid, then treating the foam metal in an alkali solution, and then washing the foam metal with water and drying the foam metal to obtain a surface modified foam metal. The modified foam metal is subjected to a flow treatment by using a lead-containing alloy melt to coat the modified foam metal and sufficiently fill the pore structure of the modified foam metal, so as to obtain the sandwich structure foam metal-lead alloy composite material. The upper surface of the lower punch of the flow treatment equipment is provided with protrusions for supporting the foam metal and forming a gap between the foam metal and the lower punch.

7. The production method according to claim 6, wherein The first treatment process further comprises an auxiliary gas, and the auxiliary gas is at least one of nitrogen or an inert gas.

8. The production method according to claim 6, wherein The pressure in the first treatment stage is greater than 1 atm.

9. The production method according to claim 8, wherein The pressure in the first treatment stage is 1.5-5 atm.

10. The production method according to claim 6, wherein The temperature in the first treatment stage is higher than 80°C.

11. The production method according to claim 10, wherein The temperature in the first treatment stage is 80-100°C.

12. The production method according to claim 6, wherein The time in the first treatment stage is 10-15 min.

13. The production method according to claim 6, wherein The solute in the alkali solution is at least one of ammonia, an alkali metal hydroxide or an alkali metal carbonate. The concentration of the solute in the alkali solution is 5-50 wt%.

14. The production method according to claim 6, wherein The surface of the foam metal treated in the second treatment stage is plated with a lead alloy material, and the plating method is electroplating.

15. The production method according to claim 14, wherein The lead alloy material is a lead-tin alloy.

16. The production method according to claim 14, wherein The plating solution used in the surface plating stage is a fluoborate plating solution, which is an aqueous solution comprising 10-50 g / L lead fluoborate, 20-50 g / L stannous fluoborate, 200-400 g / L free fluoboric acid, 0.5-1.5 g / L phenothalin, and 1-4 g / L octylphenol polyoxyethylene ether. The temperature of the surface plating stage is 50-80°C, and the current density is 3-8 A / dm 3 .

17. The production method according to claim 6, wherein The lead-containing alloy is at least one of a Pb-Ag alloy, a Pb-Ag-Ca-Sr alloy, a Pb-Ag-Nd alloy or a Pb-Ca-Sn alloy.

18. Use of the sandwich structure foam metal-lead alloy composite material of any one of claims 1-5 or the sandwich structure foam metal-lead alloy composite material prepared by the preparation method of any one of claims 6-17 as an anode.

19. The use of claim 18, wherein, to be used as an anode for a hydrometallurgical electrodeposition process.

20. An anode for use in a hydrometallurgical electrodeposition process, characterized in that A sandwich structured foam metal-lead alloy composite material according to any one of claims 1 to 5 or a sandwich structured foam metal-lead alloy composite material produced by the production method according to any one of claims 6 to 17.

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