Apparatus and method for producing metal by electrolytic reduction of molten salt

Abstract

To provide a metal production apparatus and metal production method that achieve high efficiency and low cost with small environmental contamination.SOLUTION: The apparatus comprises a reactor 1, a conductor 2, a power source 3, a gas filling and discharging mechanism 4, and a sealing mechanism 5, wherein the reactor is a barrel having a conductive bottom plate 11, insulated peripheral walls, and an opening at one end, a barrel cavity of the reactor is arranged to lay a reaction-waiting substance 6 and a molten salt substance 7 sequentially from bottom to top, the conductor is used to insert the molten salt substance after melting, the reactor and the conductor are provided inside the sealing mechanism, the power source is provided outside the sealing mechanism, a positive electrode of the power source is electrically connected to the conductor, a negative electrode of the power source is electrically connected to the bottom plate, and the gas filling and discharging mechanism is arranged to continuously fill protective gas into the reactor while removing exhaust gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to the technical field of molten salt electroreduction, and in particular to an apparatus and a method for metal production through molten salt electroreduction. [Background Art]

[0002] Traditional metal smelting technology occupies an important position in various fields such as national production and daily life. As a major steel producing country, China's annual output of pig iron exceeds 500 million tons. At present, my country's iron making technology is mainly based on blast furnace iron making. First, the flow of the blast furnace iron making process is complicated, including processes such as sintering, coking, and blast furnace iron making, which requires consumption of a large amount of energy and resources, has high cost, and is unfavorable to environmental protection. Second, blast furnace iron making needs to consume a large amount of coke as a reducing agent and raw material, and the coke refining process not only needs to consume a large amount of non-renewable coal resources, but also may generate a large amount of CO₂ and toxic gas at the same time. Finally, blast furnace iron making produces a large amount of slag, which not only occupies a large amount of space resources, but also causes serious pollution to soil. [Summary of the Invention] [Problem to be Solved by the Invention]

[0003] Embodiments of the present application provide an apparatus and a method for metal production through molten salt electroreduction, which can solve the problems of high process energy consumption and high cost of existing metal production, and disadvantages to environmental protection. [Means for Solving the Problem]

[0004] In order to achieve the above object, the technical solution of embodiments of the present invention is presented below. In the first aspect, an embodiment of the present invention provides a metal manufacturing apparatus by electrolytic reduction of molten salt, comprising a reactor, a conductor, a power supply, a gas filling and discharge mechanism, wherein the reactor is a barrel with a conductive bottom plate, an insulated peripheral wall, and an open end, the barrel cavity of the reactor is arranged so that a reaction-awaiting material and a molten salt material are laid in order from bottom to top, the conductor is used to insert the molten salt material after melting, the reactor and the conductor are provided inside the sealing mechanism, the power supply is provided outside the sealing mechanism, the positive electrode of the power supply is electrically connected to the conductor, the negative electrode of the power supply is electrically connected to the bottom plate, and the gas filling and discharge mechanism is arranged to continuously fill the reactor with protective gas while removing exhaust gas. According to the first aspect, in a possible implementation, the reactor includes a conductive bottom plate and a first insulating cylinder, the first insulating cylinder being provided on the conductive bottom plate. The outer diameter of the conductive bottom plate is greater than or equal to the outer diameter of the first insulating cylinder. According to the first aspect, in a possible implementation, the reactor includes a conductive barrel and a second insulating cylinder, the second insulating cylinder being inserted into the conductive barrel and having its bottom surface in contact with the inner bottom surface of the conductive barrel. According to the first aspect, in a possible implementation, the metal manufacturing apparatus by electrochemical reduction of molten salt further includes a first conductive rod, one end of which is electrically connected to a conductor, and the other end of which is electrically connected to the positive electrode of the power supply through the sealing mechanism. In the second phase, the embodiment of the present invention uses the metal manufacturing apparatus by electrolytic reduction of the molten salt described above, and the barrel cavity of the reactor is arranged in order from bottom to top with the reaction waiting material and the molten salt material. After heating the reactor until the molten salt substance melts, the conductor is inserted into the molten salt substance. The gas filling and discharge mechanism removes exhaust gas while continuously filling the reactor with protective gas, and the power is turned on to perform electrolytic reduction of the molten salt. The reaction in the barrel cavity is completed, the power is turned off, the molten salt material in the upper part of the barrel cavity is poured out, and the residue in the lower part is removed. The present invention provides a method for producing metal by electrolytic reduction of a molten salt, which includes obtaining a metal from the aforementioned residue. According to the second aspect, in a possible implementation, obtaining metal from the residue includes immersing the residue multiple times in ultrapure water to obtain powdered metal. According to the second aspect, in a possible implementation, obtaining a metal from the residue includes heating the residue to its melting point and then obtaining a liquid or blob of metal. According to the second aspect, in a possible implementation, the molten salt substance is one or more of the chlorides or fluorides. According to the second aspect, in a possible implementation, the awaiting material includes a metal oxide and a conductive agent. One or more technical solutions provided by the embodiments of the present invention have at least the following technical effects or advantages. Embodiments of the present invention provide a metal manufacturing apparatus by electrolytic reduction of molten salt, the apparatus comprising a reactor, a conductor, a power supply, a gas filling and discharge mechanism, and a sealing mechanism, wherein the reactor is a barrel with a conductive bottom plate, an insulated peripheral wall, and an open end, the barrel cavity of the reactor is arranged so that a reaction-awaiting material and a molten salt material are laid in order from bottom to top, the conductor is used to insert the molten salt material after melting, the reactor and the conductor are provided inside the sealing mechanism, the power supply is provided outside the sealing mechanism, the positive electrode of the power supply is electrically connected to the conductor, the negative electrode of the power supply is electrically connected to the bottom plate, and the gas filling and discharge mechanism is arranged to continuously fill the reactor with protective gas while removing exhaust gas. [Effects of the Invention]

[0005] In the metal manufacturing apparatus by electrolytic reduction of molten salt provided by the embodiment of the present invention, the reactor and conductor are placed inside the sealing mechanism, and the power supply is placed outside the sealing mechanism. The reaction-awaiting material and the molten salt material are laid in order from bottom to top in the barrel cavity of the reactor, a gas filling and discharge mechanism and a sealing mechanism are installed, the positive electrode of the power supply is electrically connected to the conductor, and the negative electrode of the power supply is electrically connected to the bottom plate of the reactor. After heating the reactor until the molten salt material melts, the conductor is inserted into the molten salt material. The gas filling and discharge mechanism removes exhaust gas while continuously filling the reactor with protective gas, and the power supply is turned on to perform electrolytic reduction of the molten salt. When the reaction in the barrel cavity of the reactor is completed, the power supply is turned off, the molten salt material in the upper part of the barrel cavity is poured out, and the residue in the lower part is removed. Finally, metal is obtained from the residue. In the metal manufacturing apparatus by electrochemical reduction of molten salt provided by the embodiment of the present invention, the bottom plate of the reactor is conductive, the peripheral wall is insulated, the cathode of the electrochemical reduction reaction of the molten salt is the conductive bottom plate of the reactor, the reaction-awaiting material and the molten salt material are laid in order from bottom to top in the barrel cavity of the reactor, and the reaction-awaiting material is in contact with and conducts only with the conductive bottom plate of the reactor, so when electrochemical reduction of the molten salt is performed, electrons move from the bottom to the top, the current is transported in a constant direction, the electrochemical reduction process of the molten salt proceeds gradually from bottom to top, forming a "resistive" reaction structure, and the efficiency of current utilization can be increased. In the metal manufacturing apparatus by electrolytic reduction of molten salt provided by the embodiment of this application, the process is simple, there is no need to consume large amounts of coke as a reducing agent and raw material, there is no need to consume large amounts of non-renewable coal resources, and there is no generation of large amounts of CO2, toxic gases and slag, resulting in low environmental pollution and achieving high efficiency and low cost. It is possible to perform electrolytic reduction of molten salt at a relatively low operating temperature and efficiently manufacture metal without relying on coke. The operation of the apparatus is relatively simple, and the electrolytic reduction process of molten salt of reaction-awaiting substances can be realized within a relatively low temperature range, which is advantageous in reducing energy consumption in the heating process. [Brief explanation of the drawing]

[0006] To more clearly illustrate the technical concepts of the embodiments of the present invention, the following is a brief introduction to the drawings that will be used in describing the embodiments of the present invention. Clearly, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these without expending any creative effort. [Figure 1] This is a schematic diagram of the structure of a metal manufacturing apparatus provided by the electrolytic reduction of molten salt according to the embodiment of the present invention. [Figure 2] This is a schematic diagram of the structure of a metal manufacturing apparatus for the electrolytic reduction of other molten salts provided by the embodiment of the present invention. [Figure 3] This is a photograph of iron powder obtained after washing the residue produced according to Example 1 of this application with water. [Figure 4] This is a photograph of an iron mass obtained after induction melting and heating of the residue produced according to Example 1 of this application. [Figure 5] This is an XRD atlas of the metal after electrolytic reduction of the molten salt in Example 1 of this application. [Figure 6] This is a photograph of the metal obtained after the electrolytic reduction of the TiO2 molten salt in Example 2 of this application. [Figure 7] This is an XRD atlas of the metal obtained by electrolytic reduction of the molten salt in Example 2 of this application. [Explanation of Symbols]

[0007] 1- Reactor, 11- Conductive bottom plate, 12- First insulating cylinder, 13- Conductive barrel, 14- Second insulating cylinder, 2- Conductor, 3- Power supply, 4- Gas filling and discharge mechanism, 41- Gas tank, 42- Gas filling pipe, 43- Exhaust pipe, 5- Sealing mechanism, 51- Furnace shell, 52- Insulation layer, 53- Hearth, 54- Furnace lid, 6- Reaction-awaiting material, 61- Metal oxide, 62- Conductive agent, 7- Molten salt material, 8- First conductive rod, 9- Second conductive rod. [Modes for carrying out the invention]

[0008] Hereinafter, the technical concepts in embodiments of the present invention will be clearly and completely described with reference to the drawings of embodiments of the present invention. Clearly, the embodiments described are not all embodiments of the present invention, but rather some embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative work based on the embodiments of the present invention are within the scope of the protection of the present invention.

[0009] In the description of embodiments of the present invention, the orientations or positional relationships indicated by terms such as “center,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “inside,” and “outside” are based on the orientations or positional relationships shown in the drawings and are merely for the purpose of describing embodiments of the present invention and simplifying the description, and do not indicate or imply that the shown devices or elements must be configured and operated in a specific orientation or direction, but rather are for the purpose of describing embodiments of the present invention and simplifying the description, and should not be understood as limiting the present invention. The terms “first,” “second,” and “third” are used solely for explanatory purposes and should not be understood as indicating or implying relative importance. Furthermore, the terms “attached,” “connected,” and “connected” should be understood in a broad sense, for example, they may be fixed connections, removable connections, or integral connections, mechanical connections, electrical connections, direct connections, indirect connections via an intermediate medium, or internal connections between two elements. Those skilled in the art will be able to understand the specific meaning of the above terms in embodiments of the present invention depending on the specific circumstances.

[0010] Referring to Figures 1 and 2, the present invention provides a metal manufacturing apparatus by electrolytic reduction of a molten salt, comprising a reactor 1, a conductor 2, a power supply 3, a gas filling and discharge mechanism 4, and a sealing mechanism 5. The metal to be manufactured may be a pure metal or an alloy.

[0011] Reactor 1 is a barrel with a conductive bottom plate, insulated perimeter walls, and an open end. The barrel cavity of reactor 1 is arranged so that the reaction-awaiting material 6 and the molten salt material 7 are laid in order from bottom to top. The bottom plate of reactor 1 may be made of metal such as stainless steel, iron, or titanium, or conductive material such as graphite. The perimeter walls can be made of high-temperature resistant insulating material such as corundum or magnesium oxide. The molten salt material 7 serves as the electrolyte for the electrolytic reduction of the molten salt.

[0012] The conductor 2 is used to insert the molten salt substance 7 after melting. The conductor 2 can be made using graphite. The shape of the conductor 2 may be columnar, trapezoidal, etc., and in this embodiment of the present invention, a graphite rod is used as an example. The rod-shaped outer wall is smooth, so no sticky substances adhere to it, making it convenient to process. Graphite has good conductivity, good chemical stability, and is stable against most acids. It has a small coefficient of linear expansion, low sensitivity to temperature changes, high thermal stability, and can resist thermal shock well. The "affinity" between graphite and most media is extremely small, so the surface of the graphite rod is not easily soiled and does not affect conductivity. Graphite has good processing properties; it cannot be rolled or forged, but it can be machined in various ways.

[0013] The reactor 1 and conductor 2 are located inside the sealing mechanism 5, and the power supply 3 is located outside the sealing mechanism 5. As shown in Figures 1 and 2, the sealing mechanism 5 may be a heating furnace or another enclosed structure. When the sealing mechanism 5 is a heating furnace, it includes a furnace shell 51, a heat retention layer 52, a hearth 53, and a furnace lid 54. The reactor 1 and conductor 2 are located inside the hearth 53. When the sealing mechanism 5 is an enclosed structure, the reactor 1, conductor 2, and other components can be pre-installed, and the entire apparatus can be arranged when it is necessary to use the apparatus.

[0014] The positive electrode of the power supply 3 is electrically connected to the conductor 2, and the negative electrode of the power supply 3 is electrically connected to the bottom plate. The gas filling and discharging mechanism 4 is arranged to continuously fill the reactor 1 with protective gas while discharging exhaust gas. Specifically, as shown in FIG. 1 and FIG. 2, the gas filling and discharging mechanism 4 includes a gas tank 41, a gas filling pipe 42, and an exhaust pipe 43. One end of the gas filling pipe 42 is connected to the output port of the gas tank 41, and the other end passes through the upper cover of the sealing mechanism 5, extends into the sealing mechanism 5, and continuously fills the reactor 1 with protective gas. The exhaust pipe 43 is inserted through the upper cover of the sealing mechanism 5 to discharge exhaust gas. The gas filling and discharging mechanism 4 fills protective gas according to actual requirements. For example, the protective gas filled in the present application is argon gas, and the gas tank 41 is an argon gas tank.

[0015] In the metal manufacturing apparatus by electrolytic reduction of molten salt provided by the embodiment of the present invention, a reactor 1 and a conductor 2 are provided inside a sealing mechanism 5, and a power supply 3 is provided outside the sealing mechanism 5. A reaction-awaiting material 6 and a molten salt material 7 are laid in the barrel cavity of the reactor 1 in order from bottom to top. A gas filling and discharge mechanism 4 and a sealing mechanism 5 are attached, the positive electrode of the power supply 3 is electrically connected to the conductor 2, and the negative electrode of the power supply 3 is electrically connected to the bottom plate of the reactor 1. After heating the reactor 1 until the molten salt material 7 melts, the conductor 2 is inserted into the molten salt material 7. Protective gas is continuously filled into the reactor 1 while exhaust gas is removed by the gas filling and discharge mechanism 4. The power supply 3 is turned on to perform electrolytic reduction of the molten salt. When the reaction in the barrel cavity of the reactor 1 is completed, the power supply 3 is turned off, the molten salt material 7 in the upper part of the barrel cavity is poured out, and the residue in the lower part is removed. Finally, metal is obtained from the residue. In the metal manufacturing apparatus by electrochemical reduction of molten salt provided by the embodiment of the present invention, the bottom plate of reactor 1 is conductive and the peripheral wall is insulated, the cathode of the electrochemical reduction reaction of molten salt is the conductive bottom plate of reactor 1, and the reaction-awaiting material 6 and the molten salt material 7 are laid in order from bottom to top in the barrel cavity of reactor 1, and the reaction-awaiting material 6 is in contact with and conducts only with the conductive bottom plate of reactor 1, so when electrochemical reduction of molten salt is performed, electrons move from the bottom to the top, the current is transported in a constant direction, the electrochemical reduction process of molten salt proceeds gradually from bottom to top, forming a "resistive" reaction structure, and the efficiency of current utilization can be increased. In the metal manufacturing apparatus by electrolytic reduction of molten salt provided by the embodiment of this application, the process is simple when performing electrolytic reduction of molten salt, there is no need to consume large amounts of coke as a reducing agent and raw material, there is no need to consume large amounts of non-renewable coal resources, and there is no generation of large amounts of CO2, toxic gases and slag, resulting in low environmental pollution and achieving high efficiency and low cost. It is possible to perform electrolytic reduction of molten salt at a relatively low operating temperature and efficiently manufacture metal without relying on coke. The operation of the apparatus is relatively simple, and the electrolytic reduction process of the molten salt of the reaction-awaiting substance 6 can be realized within a relatively low temperature range, which is advantageous in reducing energy consumption in the heating process. As shown in Fig. 1, the reactor 1 comprises a conductive bottom plate 11 and a first insulating cylinder 12. The first insulating cylinder 12 is arranged on the conductive bottom plate 11, so that the bottom plate of the reactor 1 is conductive and the peripheral wall is insulated. The reactor 1 of the embodiment of the present application has a simple structure, is easy to implement, and has low cost.

[0016] Furthermore, the outer diameter of the conductive bottom plate 11 is not smaller than the outer diameter of the first insulating cylinder 12, which can ensure the conductivity of the entire bottom of the barrel cavity of the reactor 1, leading to better effect when the device performs electroreduction in molten salt. In addition, it facilitates the electrical connection of the conductive bottom plate 11 to the power supply 3.

[0017] Preferably, as shown in Fig. 1, when the reactor 1 comprises the conductive bottom plate 11 and the first insulating cylinder 12, the gas filling pipe 42 of the gas filling and discharging mechanism 4 extends upward into the barrel cavity of the reactor 1. When the filled protective gas is a gas heavier than the exhaust gas in the cavity, such as argon, the protective gas continuously flows downward, which can discharge the exhaust gas in the barrel cavity more sufficiently and rapidly. In addition, when the gas filling pipe 42 of the gas filling and discharging mechanism 4 extends into the upper part of the barrel cavity of the reactor 1, the protective gas can fill the barrel cavity of the reactor 1 more rapidly.

[0018] Preferably, as shown in Fig. 2, the reactor 1 comprises a conductive barrel 13 and a second insulating cylinder 14. The second insulating cylinder 14 is inserted into the conductive barrel 13, and its bottom surface abuts against the inner bottom surface of the conductive barrel 13. At this time, the bottom surface of the conductive barrel 13 serves as the bottom plate of the reactor 1 for conduction, and the second insulating cylinder 14 serves as the peripheral wall of the reactor 1 for insulation. The reactor 1 provided by the embodiment of the present application has a simple structure and is easy to implement. It is only necessary to use an existing graphite crucible as the conductive barrel 13, which can save costs. In addition, the reactor 1 comprises the conductive barrel 13, which facilitates electrically connecting the negative electrode of the power supply 3 to the bottom plate of the reactor 1. The conductive barrel 13 itself is conductive as a whole, and the second insulating cylinder 14 is inserted into the conductive barrel 13, so that the negative electrode of the power supply 3 can be electrically connected to any position of the conductive barrel 13, thereby achieving the electrical connection between the negative electrode of the power supply 3 and the bottom plate of the reactor 1, which will not affect the second insulating cylinder 14.

[0019] Furthermore, when the reactor 1 includes a conductive barrel 13 and a second insulating cylinder 14, after the second insulating cylinder 14 is inserted into the conductive barrel 13, the height of the outer wall of the conductive barrel 13 becomes lower than the height of the second insulating cylinder 14. As a result, an electrical insulating layer is formed at the opening of the reactor 1, preventing it from affecting the electrochemical reduction of the molten salt.

[0020] As shown in Figure 2, when the reactor 1 includes a conductive barrel 13 and a second insulating cylinder 14, the installation of the conductive barrel 13 allows the gas filling pipe 42 of the gas filling and discharge mechanism 4 to extend into the gap between the lumen of the sealing mechanism 5 and the conductive barrel 13, thus facilitating the installation of the conductive barrel 13 and the second insulating cylinder 14 and their placement within the sealing mechanism 5.

[0021] As shown in Figures 1 and 2, the metal manufacturing apparatus by electrochemical reduction of molten salt includes a first conductive rod 8. One end of the first conductive rod 8 is electrically connected to the conductor 2, and the other end passes through the sealing mechanism 5 and is electrically connected to the positive electrode of the power supply 3. This first conductive rod 8 may be a steel rod, which is readily available and inexpensive. The conductor 2 is used to insert the molten salt substance 7 after melting, and one end of the first conductive rod 8 is connected to the conductor 2, and the other end passes through the sealing mechanism 5 and is electrically connected to the positive electrode of the power supply 3. That is, the first conductive rod 8 is drilled into the upper lid of the sealing mechanism 5, so the conductor 2 can be easily fixed and is less likely to fall, the relative positions of the conductor 2 and the molten salt substance 7 can be easily identified, and it does not affect the electrical connection of the conductor 2 to the power supply 3. Of course, the conductor 2 can also be electrically connected to the power supply 3 directly by a wire.

[0022] Furthermore, the metal manufacturing apparatus for the electrochemical reduction of molten salt includes a second conductive rod 9. The second conductive rod 9 may be a steel rod. One end of the second conductive rod 9 is electrically connected to the bottom plate of the reactor 1, and the other end passes through the sealing mechanism 5 and is electrically connected to the negative electrode of the power supply 3. The installation of the second conductive rod 9 facilitates the electrical connection of the negative electrode of the power supply 3 to the bottom plate, fixes the rod shape, and improves installation and mounting. When the reactor 1 includes a conductive bottom plate 11 and a first insulating cylinder 12, the outer diameter of the conductive bottom plate 11 is greater than or equal to the outer diameter of the first insulating cylinder 12, facilitating the electrical connection of the second conductive rod 9 to the conductive bottom plate 11, requiring only contact between the outer edge of the conductive bottom plate 11 and the second conductive rod 9. The installation of the second insulating cylinder 14 ensures that the peripheral wall of the reactor 1 remains insulated after the second conductive rod 9 is installed. Of course, the conductor 2 can also be electrically connected to the power supply 3 by a wire. Furthermore, since the apparatus needs to be heated when performing the electrolytic reduction of the molten salt, the first conductive rod 8 and the second conductive rod 9 are heat-resistant.

[0023] Another embodiment of the present invention provides a method for producing metal by electrolytic reduction of a molten salt, comprising steps 301 to 305, using the above-described metal production apparatus by electrolytic reduction of a molten salt.

[0024] Step 301: The reaction-awaiting material 6 and molten salt material 7 are laid in the barrel cavity of reactor 1 from bottom to top. In this configuration, the molten salt substance 7 is one or more of chlorides or fluorides. Preferably, the molten salt substance 7 is a mixture of chlorides or fluorides, so that the electrolyte is a molten salt mixture, the eutectic temperature of the molten salt substance 7 is lowered, the temperature required to heat the molten salt substance 7 during the process in which the apparatus performs electrolytic reduction of the molten salt is lowered, and electrolytic reduction of the molten salt substance 7 in the temperature range of 600°C-1200°C can be achieved. For example, this molten salt substance 7 consists of one or more of NaCl, KCl, CaCl2, NaF, KF, CaF2, etc.

[0025] The awaiting material 6 contains a metal oxide 61 and a conductive agent 62. Since the conductive agent 62 is part of the components of the metal to be manufactured, once the reaction of the awaiting material 6 is complete, there is no need to further remove the conductive agent 62, and the conductive agent 62 also becomes part of the manufactured metal.

[0026] The conductive agent 62 functions as a conductive and inductive medium for the metal oxide 61 in the electro-reduction process of the molten salt. As a conductive medium, the conductive agent 62 is doped between the powder particles of the metal oxide 61, uniformly distributing the conductive agent 62 between the powder particles of the metal oxide 61, increasing the conductivity of the awaiting material 6, improving the current conduction and electrochemical reaction power, enhancing the reaction effect of the electro-reduction of the molten salt, eliminating the need for coke compared to conventional technology, and significantly reducing energy consumption and environmental pollution. As an inductive medium, the conductive agent 62 can be used to provide auxiliary internal heating when inductively heating the apparatus. The metal oxide 61 in the awaiting material 6 can be in powder form and perform the electro-reduction of the molten salt without requiring compression, shortening the time required to produce the metal, and the metal oxide 61 has a large specific oxygen area, resulting in a fast reaction rate. For example, the conductive agent 62 may be various biomast toners such as metal powders of Al, Fe, Ti, etc. Specifically, a mixture of metal oxide 61 and conductive agent 62 is laid at the bottom of reactor 1, compacted, and then molten salt material 7 is laid on top of it to form the structural characteristics of the lower reaction-awaiting material 6 and the upper molten salt material 7.

[0027] Step 302: After heating reactor 1 until the molten salt material 7 melts, the conductor 2 is inserted into the molten salt material 7. For example, this heating process may be induction heating, resistance wire heating, and fuel combustion heating.

[0028] Step 303: The gas filling and discharge mechanism 4 continues to fill the reactor 1 with protective gas and remove exhaust gas while the power supply 3 is turned on to perform electrochemical reduction of the molten salt. For example, argon gas from the argon gas tank is continuously filled into the reactor 1 via the gas filling pipe 42, while exhaust gas such as air is removed via the exhaust pipe 43, and the exhaust gas overflows from the molten salt material 7 due to buoyancy. The positive electrode of the power supply 3 is electrically connected to the conductor 2, and the negative electrode of the power supply 3 is electrically connected to the bottom plate of the reactor 1, and electrochemical reduction is performed with a constant current or constant voltage.

[0029] Step 304: The reaction in the barrel cavity is complete, so turn off the power supply 3, pour out the molten salt material 7 from the top of the barrel cavity, and remove the residue from the bottom.

[0030] Step 305: Obtain metal from the residue.

[0031] Furthermore, step 305: Obtaining metal from the residue is, The residue was immersed multiple times in ultrapure water to obtain powdered metal. Specifically, after cooling the lower solid residue, the molten salt was electrolyzed, and the resulting residue was immersed in ultrapure water to remove any remaining molten salt material 7. This process was repeated 3-4 times, the residue was washed with anhydrous alcohol, and the material was dried to obtain powdered metal. Preferably, step 305: Obtaining metal from the residue, The residue is heated until it reaches its melting point, after which a liquid or solid metal is obtained. For example, the residue can be induced melted and heated, the molten salt substance 7 remaining in the residue can be volatilized and recovered, and a liquid or solid metal can be obtained once it reaches its melting point.

[0032] By repeating steps 301-305 described above, the metal oxide 61 is continuously reduced to metal, and the poured molten salt substance 7 can be reused repeatedly, thus avoiding the defect of generating large amounts of slag in conventional technologies such as steelmaking processes.

[0033] The metal manufacturing method by electrolytic reduction of molten salt provided by the embodiment of this application can perform electrolytic reduction of molten salt, has fewer process steps, and can reduce the cost of metal manufacturing.

[0034] Specific examples of the metal manufacturing apparatus and method by electrolytic reduction of molten salt provided by the embodiments of this application are as follows.

[0035] Example 1: Production of metallic iron by electrolytic reduction of molten salt A corundum tube is inserted into a conductive crucible to obtain reactor 1. A mixture of 20g Fe3O4 and 0.8g toner is laid at the bottom of reactor 1 as a reaction-awaiting material 6 and compressed. Then, 160g of a molten salt material 7, a mixture of NaCl and NaF in a molar ratio of 1:1, is laid on top. Reactor 1 is placed in a heating furnace and heated, and after the temperature rises to 800°C, the electro-reduction process of the molten salt is started. Argon gas is continuously passed through the heating furnace by a gas filling and discharge mechanism 4 to protect it and prevent oxidation of the metal at high temperatures.

[0036] The connection wires of power supply 3 (Koi PSM-3004) were connected to the cathode (bottom of reactor 1) and anode (graphite rod) of the apparatus, respectively. An electro-reduction process of the molten salt was carried out for 7.0 hours under a current of 2.0 A, and all of the Fe3O4 was reduced to iron metal.

[0037] After the reaction in the barrel chamber of reactor 1 is complete, the power supply 3 is turned off, the crucible is removed, and the molten salt substance 7 is poured out and recycled. Two methods can be used to separate the remaining molten salt substance 7 from metallic iron. (1) Water washing method: After cooling the crucible, the residue in the crucible is washed by immersing it in ultrapure water 5-6 times to remove the remaining molten salt substance 7. After further washing with anhydrous ethanol 2-3 times and drying, powdered pure metal is obtained as shown in Figure 3. (2) Heating method: The residue after electroreduction is heated in an induction furnace at a temperature range of 1000°C to 1200°C to volatilize and recover the molten salt substance 7, obtaining solid metallic iron as shown in Figure 4. Figure 5 shows the results of XRD detection of the metal obtained by electroreduction of the molten salt. The substance obtained after electroreduction of the molten salt is all pure iron metal except for small amounts of Fe and C compounds.

[0038] Example 2: Production of titanium-aluminum alloy by electrolytic reduction of molten salt An insulating sleeve was inserted into a graphite crucible to obtain reactor 1, and the gap between the graphite crucible and the insulating sleeve was sealed with high-temperature AB rubber. A hole with a diameter of 1.5 mm and a depth of 0.5 mm was drilled in the upper end of the graphite crucible, and a polished, bright wire with a length of 1.5 m was inserted into this hole. The opening of the hole was sealed with high-temperature AB rubber, and after standing still at room temperature for 12 hours, it was transferred to a tubular furnace, kept warm at 100°C and 150°C for 2 hours each, and then cooled to room temperature according to the furnace temperature before being removed.

[0039] 20g of TiO2 was laid at the bottom of reactor 1 and compacted. 29.3g of Al ingot was polished smooth and placed on top of the TiO2 sample in reactor 1. Then, dried Na3AlF6 molten salt material 7 was laid on top of the Al ingot. Reactor 1 was placed in a heating furnace and heated until the temperature rose to 1150°C, with argon gas continuously flowing through the furnace to protect the metal from oxidation at high temperatures. The connection wires of power supply 3 (Gow PSM-3004) were connected to the cathode (bottom of the graphite crucible) and anode (graphite rod) of the apparatus, respectively.

[0040] An electro-reduction process was carried out for 60 minutes under a voltage of 3.0V to reduce all TiO2 to Al3Ti. After the electro-reduction of the molten salt was complete, the power supply 3 was turned off, the graphite crucible was removed, and the molten salt material 7 was poured out and recycled. After the crucible cooled, the residue in the crucible was washed 5-6 times by immersing it in ultrapure water to remove the remaining molten salt material 7. Then the product was further decontaminated by placing it in dilute hydrochloric acid at 0.1 mol / L, and finally washed 2-3 times with anhydrous ethanol, dried, and sealed for storage. Here, the metal after electro-reduction of the molten salt was gray as shown in Figure 6, and after polishing it had a metallic luster. The XRD detection results of this metal, as shown in Figure 7, showed that only the Al3Ti phase was present, with no other impurities, and its diffraction peak was comparable to that of a standard card with no offset.

[0041] Example 3: Cost analysis of the production of metallic iron by electrolytic reduction of molten salt.

[0042] 1. Main costs (1) Raw material costs: The raw materials are iron powder ore and biomass coal. Of these, the main component used in the laboratory stage was iron powder ore (Fe3O4), and the added carbon source was biomass coal. Industrially, it can be substituted with lower-cost orchid coal than metallurgical coke, and the market prices of iron powder ore and orchid coal are approximately 769 yuan / ton and 1616.67 yuan / ton, respectively, as revealed by steel industry data.

[0043] (2) Power consumption cost of the molten salt electrolytic reduction process Taking electrolysis at a constant current of 2.0A for 7 hours as an example, calculations based on the voltage curve of the electrolytic reduction process of the molten salt show that the power consumption is approximately 28.1 W·h, or 0.0281 degrees of electricity. At an industrial electricity rate of 0.5 yuan / degree, the power consumption for this process is 0.01405 yuan.

[0044] 2. Raw material and electricity consumption during the production of 1 ton of reduced iron powder. During the experiment, 20g of Fe3O4 (iron powder) and 0.8g of biomass coal (orchid coal) were electrolyzed for 7 hours under a constant current of 2.0A, recovering 10.04g of iron. The power consumption for this process, as calculated above, was 0.0281 degrees of electricity (0.5 yuan / degree, or 0.01405 yuan). Scaled proportionally, it can be calculated that 2800 degrees of electricity are needed to produce 1 ton of iron. Using an industrial electricity price of 0.5 yuan / degree, the electricity cost to produce 1 ton of iron is approximately 1400 yuan.

[0045] 3. Main costs of producing 1 ton of reduced iron powder Producing one ton of iron requires 1.992 tons of iron powder, 0.07968 tons of orchid coal, and 2800 degrees of electricity. Therefore, the cost of producing one ton of iron using this technology can be calculated to be approximately 3060.65 yuan. This represents a significant reduction in the cost of producing one ton of iron compared to conventional technology. Each embodiment described herein is described progressively, and identical or similar parts between embodiments may refer to one another. Each embodiment will focus on describing how it differs from the others.

[0046] The embodiments described above are not limiting to the present application, but are used solely to illustrate the technical proposal of the present application. Although the present application has been described in detail with reference to the embodiments described above, those skilled in the art can modify the technical proposals described in the embodiments above, or replace some or all of the technical features thereof, and such modifications or replacements will not cause the essence of the corresponding technical proposals to deviate from the scope of the technical proposals of the present application.

Claims

1. A metal manufacturing apparatus for electrolytic reduction of molten salt, It includes a reactor, a conductor, a power supply, a gas filling and discharge mechanism, and a sealing mechanism. The reactor is a barrel with a conductive bottom plate, an insulated perimeter wall, and an open end, and the barrel cavity of the reactor is arranged so that a reaction-awaiting material and a molten salt material are laid in order from bottom to top, the reaction-awaiting material contains a metal oxide and a conductive agent, the conductive agent is a component of the metal to be manufactured, the molten salt material is a variety of fluorides, and the reaction-awaiting material undergoes an electro-reduction reaction with the molten salt material. The reactor includes a conductive barrel and a second insulating cylinder. The second insulating cylinder is inserted into the conductive barrel, and its bottom surface abuts against the inner bottom surface of the conductive barrel, and the height of the outer wall of the conductive barrel is lower than the height of the second insulating cylinder. The conductor is used to be inserted into the molten salt substance after melting. The reactor and the conductor are provided inside the sealing mechanism, and the power supply is provided outside the sealing mechanism. The sealing mechanism is a heating furnace, and the heating furnace includes a furnace shell, an insulating layer, a hearth, and a furnace lid, and the reactor and the conductor are provided inside the hearth. The positive electrode of the power supply is electrically connected to the conductor, and the negative electrode of the power supply is electrically connected to the bottom plate. The gas filling and discharge mechanism is arranged to continuously fill the reactor with protective gas while removing exhaust gas. A metal manufacturing apparatus characterized by the electrolytic reduction of a molten salt.

2. Further comprising a first conductive rod, One end of the first conductive rod is electrically connected to a conductor, and the other end passes through the sealing mechanism and is electrically connected to the positive electrode of the power supply. A metal manufacturing apparatus by electrolytic reduction of a molten salt as described in item 1.

3. A method for producing metal by electrolytic reduction of a molten salt, using the metal production apparatus for electrolytic reduction of a molten salt described in Claim 1 or 2, The barrel cavity of the reactor is laid out in order from bottom to top, with the reaction-awaiting material and the molten salt material being laid out in that order. After heating the reactor until the molten salt substance melts, the conductor is inserted into the molten salt substance. The gas filling and discharge mechanism removes exhaust gas while continuously filling the reactor with protective gas, and the power is turned on to perform electrolytic reduction of the molten salt. The reaction in the barrel cavity is completed, the power is turned off, the molten salt material in the upper part of the barrel cavity is poured out, and the residue in the lower part is removed. The process includes obtaining a metal from the aforementioned residue. A method for producing metal by electrolytic reduction of a molten salt, characterized by the following features.

4. Obtaining metal from the aforementioned residue is possible. This includes obtaining powdered metal by repeatedly immersing the aforementioned residue in ultrapure water. A method for producing metal by electrolytic reduction of a molten salt as described in feature 3.

5. Obtaining metal from the aforementioned residue is possible. This includes heating the aforementioned residue to reach its melting point and then obtaining a liquid or lumpy metal. A method for producing metal by electrolytic reduction of a molten salt as described in feature 3.

6. The molten salt substance is one or more of the following: chloride or fluoride. A method for producing metal by electrolytic reduction of a molten salt as described in feature 3.

7. The reaction-awaiting material includes a metal oxide and a conductive agent. A method for producing metal by electrolytic reduction of a molten salt as described in feature 3.

Images