Electrometallurgy method
By using gas diffusion electrodes and hydrogen oxidation reactions in electrolytic metallurgy, the high energy consumption and carbon emission problems of traditional smelting technology are solved, and an efficient and environmentally friendly electrolytic metallurgy process is achieved.
Patent Information
- Application Number
- CN202510035041.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2025-05-06
AI Technical Summary
Traditional metal smelting technology has high energy consumption and serious carbon emission problems. Electrolytic metallurgy technology produces harmful gases in the anode and has low energy utilization, which hinders the widespread application of its green smelting.
A gas diffusion electrode is used as anode to inject a metal salt solution into the electrolytic cell, and hydrogen-containing gas is introduced into the anode, replacing the traditional oxygen precipitation reaction through hydrogen oxidation reaction to achieve electrolytic metallurgy.
It effectively reduces the harmful gas emissions of the anode, achieves the goal of zero carbon emissions, improves electrolytic efficiency, reduces overall energy consumption, and conforms to the concept of green smelting.
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Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of metal smelting, and in particular to an electrolytic metallurgical method. Background Art
[0002] Metal materials are key resources for social development. At present, the metal smelting process still widely uses traditional blast furnace smelting technology and molten electrolysis technology. Although these methods are effective, they consume huge amounts of energy and emit significant carbon emissions, especially in the steel industry, which accounts for 8% of global emissions, while the electrolytic aluminum industry consumes more than 6.7% of social electricity consumption. In the face of the urgent global demand for energy conservation and emission reduction, traditional smelting technology is in urgent need of innovation.
[0003] In recent years, electrolytic metallurgy technology has gradually attracted attention as a potential solution to reduce carbon emissions from metal smelting. It can use electricity generated by renewable energy to electrolyze electrolytes containing metal elements and deposit metal elements at the cathode. However, related electrolytic technologies still have problems such as harmful gas emissions from the anode and low energy utilization, which hinders its widespread application in green smelting. Therefore, there is an urgent need to further optimize and improve electrolytic metallurgy technology to achieve a more efficient and environmentally friendly metal smelting process. Summary of the invention
[0004] In view of this, the main purpose of the present disclosure is to provide an electrolytic metallurgical method in order to at least partially solve at least one of the above-mentioned technical problems.
[0005] To achieve the above purpose, the technical solution of the present invention is as follows:
[0006] In one aspect of the present disclosure, there is provided an electrowinning method comprising:
[0007] In the electrolytic cell, a gas diffusion electrode is used as the anode and a conductive substrate is used as the cathode. A metal salt solution is continuously injected into the electrolytic cell, and a hydrogen-containing gas is introduced into the anode at the same time. By applying an electric current, a hydrogen oxidation reaction occurs at the anode and a metal cation reduction reaction occurs at the cathode, thereby realizing electrolytic metallurgy. The gas diffusion electrode includes a porous material negative and a catalyst loaded on the porous material.
[0008] According to the embodiments of the present disclosure, by introducing hydrogen to participate in the electrolysis reaction in electrolytic metallurgy, the emission of harmful gases at the anode is effectively reduced. Since the main product of the hydrogen reaction is water, the present disclosure replaces the traditional blast furnace ironmaking process that originally produced a large amount of greenhouse gases, effectively reducing the generation of carbon dioxide, thereby achieving the goal of zero carbon emissions. At the same time, the use of gas diffusion electrode technology provides a stable gas diffusion channel for the electrolysis process, effectively preventing the accumulation of gas at the electrode, ensuring the continuity and efficiency of electron transmission, and thus significantly improving the electrolysis efficiency. In addition, the oxidation reaction of hydrogen replaces the traditional oxygen evolution reaction or chlorine evolution reaction on the cathode, which not only reduces the cell voltage required in the electrolysis process, but also further reduces the overall energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 An electrolysis apparatus for carrying out electrowinning metallurgy for the present disclosure is intended;
[0010] Figure 2 is an X-ray diffraction pattern of the electrolysis product collected at the cathode in Example 1 of the present disclosure;
[0011] Figure 3 The graph is a graph showing changes in the electrolytic cell voltage during electrolysis for about 0.5 hours under constant current conditions in Example 1 and Comparative Example 1 of the present disclosure;
[0012] Figure 4 This is a diagram showing the components of the tail gas from the cathode of the electrolytic cell during the electrolysis process in Examples 1 to 4 and Comparative Examples 1 to 2 of the present disclosure. DETAILED DESCRIPTION
[0013] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments.
[0014] The endpoints and any values of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this disclosure.
[0015] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.
[0016] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.
[0017] Metal materials are essential for industrial production and daily life, but traditional smelting methods, such as blast furnace smelting and molten electrolysis, are controversial due to their high energy consumption and serious carbon emissions. In order to reduce carbon emissions and energy consumption in the metal smelting process, electrolytic metallurgy technology has been proposed as an alternative. This technology uses electricity generated by renewable energy to electrolyze electrolytes containing metal elements, deposits iron at the anode, avoids the use of carbon in traditional processes, and thus achieves the goal of zero emissions. However, the relevant electrolysis process still produces harmful gases at the anode, and the energy utilization rate is not ideal, which does not conform to the concept of green smelting.
[0018] In the process of realizing the concept of the present disclosure, it was found that by introducing hydrogen to participate in the electrolysis reaction in electrolytic metallurgy, the generation of carbon dioxide can be effectively reduced and the goal of zero carbon emissions can be achieved. The main product after the hydrogen reaction is water, which not only reduces carbon emissions, but also avoids greenhouse gas emissions in traditional electrolysis processes. At the same time, the use of gas diffusion electrode technology provides a stable gas diffusion channel for the electrolysis process, effectively prevents the accumulation of gas at the electrode, ensures the continuity and efficiency of electron transmission, and thus significantly improves the electrolysis efficiency. In addition, the oxidation reaction of hydrogen replaces the traditional oxygen precipitation reaction, which not only reduces the cell voltage required in the electrolysis process, but also further reduces the overall energy consumption, which is in line with the concept of green smelting and has the potential for large-scale application, providing new possibilities for achieving environmentally friendly and economically efficient metal smelting.
[0019] According to an embodiment of one aspect of the present disclosure, there is provided an electrolytic metallurgical method, comprising:
[0020] In the electrolytic cell, a gas diffusion electrode is used as the anode and a conductive substrate is used as the cathode. A metal salt solution is continuously injected into the electrolytic cell, and a hydrogen-containing gas is introduced into the anode at the same time. By applying an electric current, a hydrogen oxidation reaction occurs at the anode and a metal cation reduction reaction occurs at the cathode, thereby realizing electrolytic metallurgy. The gas diffusion electrode includes a porous material negative and a catalyst loaded on the porous material.
[0021] According to the embodiments of the present disclosure, by introducing hydrogen to participate in the electrolysis reaction, the emission of harmful gases at the anode is effectively reduced. The main product of the hydrogen reaction is water, which significantly reduces the production of carbon dioxide and helps to achieve the goal of zero carbon emissions. In addition, a gas diffusion electrode is used as the anode of the electrolytic cell, which provides a stable gas diffusion channel for the electrolysis process, effectively prevents the accumulation of gas at the electrode, ensures the continuity and efficiency of electron transfer, and significantly improves the electrolysis efficiency. By replacing the traditional oxygen evolution reaction with the oxidation reaction of hydrogen, we not only reduce the cell voltage required in the electrolysis process, but also further reduce the overall energy consumption, and improve the efficiency and sustainability of electrolytic metallurgy.
[0022] According to an embodiment of the present disclosure, the porous material in the gas diffusion electrode is selected from one or more of carbon fiber, nickel foam and stainless steel mesh. The above porous material has strong mechanical strength and corrosion resistance, and its porous structure is conducive to the diffusion of gas, so that the electrode is significantly improved in terms of gas transmission efficiency, electronic conductivity, stability and durability. The catalyst is selected from any one or more metals of platinum, platinum black, nickel, iron, copper, silver, gold, cobalt, manganese, palladium, rhodium, rubidium, ruthenium and molybdenum. The metal catalyst provides efficient catalytic activity to promote the hydrogen oxidation reaction on the gas diffusion electrode, which not only enhances the conductivity and electron transfer ability of the electrode, but also significantly improves the rate and efficiency of the electrochemical reaction by reducing the reaction overpotential and accelerating the activation of gas molecules.
[0023] According to the embodiments of the present disclosure, the catalyst loading is 0.01-10 mg / cm 2 , for example, it can be 0.01 mg / cm 2 , 0.05 mg / cm 2 , 0.1 mg / cm 2 , 0.5 mg / cm 2 , 1 mg / cm 2 , 5 mg / cm 2 , 10 mg / cm 2 etc., more preferably 0.1~1 mg / cm 2 The appropriate loading range can ensure sufficient active sites to optimize reaction kinetics while avoiding crowding of active sites or reduced catalyst stability due to excessive loading.
[0024] According to an embodiment of the present disclosure, the diameter of the gas diffusion channel in the gas diffusion electrode is 0.01~5000 μm, for example, it can be 0.01 μm, 0.1 μm, 1 μm, 10 μm, 50 μm, 500 μm, 5000 μm, etc., and it is further preferably 0.1~50 μm. The appropriate pore size range can ensure the effective diffusion of gas in the electrode while maintaining the structural stability and functionality of the electrode. The porosity is 0.1%~80%, for example, it can be 0.1%, 1%, 10%, 30%, 50%, 80%, etc., and it is further preferably 1~50%. The appropriate porosity helps to balance the gas transmission efficiency and the structural stability of the electrode. By precisely controlling the pore size and porosity size, the gas diffusion electrode can achieve optimal gas exchange efficiency and mechanical stability in electrochemical processes such as electrolytic metallurgy, thereby improving the overall energy conversion efficiency and operational stability.
[0025] According to an embodiment of the present disclosure, the conductive substrate is selected from a metal substrate and / or a carbon substrate, and the metal substrate is selected from any one or more of magnesium, aluminum, zinc, iron, tin, copper, silver, and gold. Selecting a substrate material with high conductivity and structural stability as the cathode can efficiently transmit current and promote metal deposition to ensure the stable and smooth progress of the electrolytic metallurgical reaction.
[0026] According to the embodiments of the present disclosure, the hydrogen-containing gas is any one of hydrogen, hydrogen-argon mixed gas, and hydrogen-nitrogen mixed gas. The introduction of hydrogen effectively suppresses the oxygen evolution reaction originally occurring on the anode:
[0027]
[0028] Or chlorine evolution reaction:
[0029]
[0030] This in turn promotes the hydrogen oxidation reaction at a lower electrode potential:
[0031]
[0032] Compared with the gas evolution reaction with severe polarization, the polarization of hydrogen oxidation reaction is lower and the internal resistance is smaller during operation, which significantly reduces the cell pressure required for the electrolyzer during operation, further reduces the energy loss during electrolysis, and improves the energy efficiency of the electrolysis process. The product of hydrogen oxidation reaction is only water, which helps to reduce the generation of carbon dioxide and achieve a more environmentally friendly electrolysis process.
[0033] According to an embodiment of the present disclosure, the metal ions (M n+) is selected from any one or more of magnesium, aluminum, iron, tin and copper ions; anions are selected from any one or more of sulfate, sulfite, nitrate, nitrite, acetate, phosphate and chloride ions. For example, it can be ferric sulfate, ferrous chloride, aluminum nitrate, magnesium sulfate, tin phosphate, copper nitrite and the like. The solvent of the metal salt solution is water or a mixture of water and one or more of ethanol, isopropanol, ethylene glycol, glycerol and dimethyl sulfone.
[0034] According to the embodiments of the present disclosure, the concentration range of the metal salt solution is 0.01-10 mol / L, for example, 0.01 mol / L, 0.1 mol / L, 1 mol / L, 5 mol / L, 10 mol / L, etc. The concentration will affect the working voltage of the electrolytic cell during operation, causing concentration polarization. The lower the concentration, the greater the concentration polarization. However, excessive concentration will also cause the solution conductivity to decrease, resulting in increased polarization.
[0035] According to an embodiment of the present disclosure, the flow rate of the metal salt solution injection is 0.01~1000 ml / min, for example, it can be 0.01 ml / min, 0.1 ml / min, 1 ml / min, 10 ml / min, 100 ml / min, 500 ml / min, 1000 ml / min, etc., preferably 1~100 ml / min. The current density of the current is 0.1~10000 mA / cm 2 , for example, 0.1 mA / cm 2 , 1mA / cm 2 , 10 mA / cm 2 , 50 mA / cm 2 , 100 mA / cm 2 , 1000 mA / cm 2 , 10000 mA / cm 2 etc., preferably 1~100mA / cm 2 The electrolytic metallurgy method disclosed in the present invention can be carried out at a lower flow rate and a lower current density, and while ensuring the metal extraction efficiency, it significantly reduces energy consumption, thereby reducing the overall energy consumption in the electrolytic process, improving energy utilization efficiency, and making the electrolytic metallurgy process more environmentally friendly and economically efficient.
[0036] Figure 1 An electrolysis apparatus for performing electrowinning is intended for the present disclosure.
[0037] like Figure 1As shown in the figure, the electrolysis device mainly consists of three parts: electrolytic cell, circulation pump and electrolyte storage bottle. Among them, the electrolytic cell contains a cathode, an anode (gas diffusion electrode) and an injected electrolyte. In the electrolytic metallurgy process, a metal salt solution is injected into the electrolytic cell as an electrolyte, and a hydrogen-containing gas is introduced into the gas diffusion electrode. When the current passes through the electrolyte, hydrogen undergoes a hydrogen oxidation reaction on the gas diffusion electrode:
[0038]
[0039] Metal cations undergo reduction reaction at the cathode
[0040]
[0041] The metal cations gain electrons and are reduced to metal atoms, which are then deposited on the cathode surface to form a metal layer, completing electrolytic metallurgy.
[0042] According to the embodiment of the present disclosure, the temperature of electrolytic metallurgy is 20° C. to 30° C. The electrolytic metallurgy method of the present disclosure does not require high-temperature heating operation and can be performed at room temperature, saving energy consumption and simplifying the process flow, making the electrolytic metallurgy process more economical and environmentally friendly.
[0043] In order to make the purpose, technical scheme and advantages of the present disclosure more clear, the present disclosure is further described in detail below in conjunction with specific embodiments and drawings. Specific techniques or conditions not specified in the embodiments are conventional methods and can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.
[0044] Embodiment 1:
[0045] In the electrolyzer, a 20 μm thick nickel foil was used as the cathode, and a 150 μm thick carbon fiber paper loaded with platinum black catalyst was used as the anode. The anode and cathode materials were cut into strips of 2 cm × 5 cm and installed on both sides of the electrolyzer. The anode was used as a gas diffusion electrode, and the platinum black catalyst loading was 1 mg / cm 2 , pore size is 100 μm and porosity is 40%.
[0046] 2 mol / L ferrous chloride solution was continuously injected into the electrolytic cell at a flow rate of 100 ml / min through an external circulation pump. At the same time, hydrogen was introduced into the anode side at a flow rate of 100 ml / min. After 5 minutes of hydrogen introduction, a 100 mA / cm 2 Electrolytic metallurgy is carried out with an electric current of a current density of 10000 W, a hydrogen oxidation reaction occurs at the anode, an iron ion reduction reaction occurs at the cathode, and the electrolytic metallurgical products are collected at the cathode.
[0047] Figure 2 This is the X-ray diffraction pattern of the electrolysis product collected at the cathode in Example 1 of the present disclosure.
[0048] like Figure 2 As shown, the product collected at the cathode was analyzed using an X-ray diffractometer, and based on the position and intensity of the diffraction peaks in the spectrum, the analysis proved that the product was a single substance of iron.
[0049] The following calculation method is used to obtain the electric energy consumption and coulombic efficiency required for the iron smelting technology proposed in the present invention:
[0050]
[0051]
[0052] W: Unit electrical energy required for iron smelting
[0053] E: Electrolytic cell pressure
[0054] I: electrolytic cell working current
[0055] t: electrolytic cell working time
[0056] : Cathode mass after electrolysis
[0057] : Cathode mass before electrolysis
[0058] M: mass of cathode product
[0059] : Coulomb efficiency of current
[0060] M: molar mass of the metal element
[0061] z: the charge number of the metal ion
[0062] F: Faraday constant
[0063] After calculation, the Coulomb efficiency of the current reached 95%, and the final energy consumption of hydrogen-assisted electrolysis was 1.45 MWh / ton, which is significantly lower than the energy consumption of electrolysis under air (about 3.1 MWh / ton) and the current average energy consumption of the steel smelting industry (about 3 MWh / ton).
[0064] Example 2
[0065] The difference between Example 2 of the present disclosure and Example 1 is that 200 mA / cm 2 The electrolytic metallurgy is carried out with a current of a current density of , and the other steps are the same as those in Example 1.
[0066] Example 3
[0067] The difference between Example 3 of the present disclosure and Example 1 is that 300 mA / cm 2 The electrolytic metallurgy is carried out with a current of a current density of , and the other steps are the same as those in Example 1.
[0068] Example 4
[0069] The difference between Example 4 of the present disclosure and Example 1 is that 400 mA / cm 2 The electrolytic metallurgy is carried out with a current of a current density of , and the other steps are the same as those in Example 1.
[0070] Comparative Example 1:
[0071] Compared with Example 1, Comparative Example 1 of the present disclosure is different in that the gas introduced into the gas diffusion electrode is air, and the other steps are the same as those of Example 1.
[0072] Comparative Example 2:
[0073] The difference between the comparative example 2 of the present disclosure and the comparative example 1 is that 200 mA / cm 2 The electrolytic metallurgy was carried out with a current of a current density of , and the other steps were the same as those in Comparative Example 1.
[0074] Figure 3 This is a graph showing the change in the electrolytic cell voltage during electrolysis for about 0.5 hours under constant current conditions in Example 1 and Comparative Example 1 of the present disclosure.
[0075] like Figure 3 As shown in the figure, the voltage of the electrolytic cell can remain stable during the entire electrolysis process. As the electrolysis reaction proceeds, the electrolysis products gradually deposited on the cathode cause the cathode covering layer to gradually increase, and the distance between the anode and the cathode decreases accordingly, resulting in a decrease in the resistance inside the electrolytic cell. Therefore, as the internal resistance decreases, the voltage in the electrolytic cell also shows a downward trend.
[0076] Figure 4 This is a diagram showing the components of the tail gas from the cathode of the electrolytic cell during the electrolysis process in Examples 1 to 4 and Comparative Examples 1 to 2 of the present disclosure.
[0077] like Figure 4 As shown, the tail gas during electrolysis passes through a 2 mol / L ferrous chloride solution. If chlorine is produced during electrolysis, the solution changes from green to yellow, otherwise it remains unchanged. It can be observed that when the tail gas passes through the ferrous chloride solution under different current densities of hydrogen, the solution does not change color, while the tail gas caused by electrolysis in the air contains chlorine, which causes the solution to change color significantly.
[0078] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.
Claims
1. An electrolytic metallurgical method comprising: In an electrolytic cell, a gas diffusion electrode is used as an anode and a conductive substrate is used as a cathode. A metal salt solution is continuously injected into the electrolytic cell, and a hydrogen-containing gas is introduced into the anode. By applying an electric current, a hydrogen oxidation reaction occurs at the anode and a metal cation reduction reaction occurs at the cathode, thereby realizing electrolytic metallurgy, wherein the gas diffusion electrode includes a porous material negative and a catalyst loaded on the porous material.
2. The method according to claim 1, wherein: The catalyst is selected from any one or more metals selected from platinum, platinum black, nickel, iron, copper, silver, gold, cobalt, manganese, palladium, rhodium, rubidium, ruthenium, and molybdenum; The porous material is selected from any one or more of carbon fiber, nickel foam and stainless steel mesh.
3. The method according to claim 2, wherein: The catalyst loading is 0.01-10 mg / cm 2 .
4. The method according to claim 1, wherein: The concentration range of the metal salt solution is 0.01-10 mol / L.
5. The method according to claim 1, wherein: The diameter of the gas diffusion channel in the gas diffusion electrode is 0.01-5000 μm, and the porosity is 0.1%-80%.
6. The method according to claim 1, wherein: The conductive substrate is selected from a metal substrate and / or a carbon substrate, and the metal substrate is selected from any one or more of magnesium, aluminum, zinc, iron, tin, copper, silver, and gold.
7. The method according to claim 1, wherein: The hydrogen-containing gas is any one of hydrogen, hydrogen-argon mixed gas, and hydrogen-nitrogen mixed gas.
8. The method according to claim 1, wherein: The metal ions in the metal salt solution are selected from any one or more of magnesium, aluminum, iron, tin and copper ions; the anions are selected from any one or more of sulfate, sulfite, nitrate, nitrite, acetate, phosphate and chloride ions; The solvent of the metal salt solution is water, or a mixture of water and one or more of ethanol, isopropanol, ethylene glycol, glycerol, and dimethyl sulfone.
9. The method according to claim 1, wherein: The flow rate of the metal salt solution injection is 0.01-1000 ml / min, preferably 1-100 ml / min; The current density of the current is 0.1-10000 mA / cm 2 , preferably 1~100 mA / cm 2 .
10. The method according to claim 1, wherein: The temperature of the electrolytic metallurgy is 20-30°C.