Metal production apparatus and method by electrical 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] This application relates to the technical field of electroreduction of molten salts, and particularly to a metal manufacturing apparatus and method by electroreduction of molten salts.

Background Art

[0002] Traditional metal smelting technologies occupy an important position in various fields such as the national production and life. As a major steel-producing country, China's annual pig iron production exceeds 500 million tons. Currently, the iron-making technology in our country mainly relies on blast furnace iron-making. First, the process flow of blast furnace iron-making is complex, including processes such as sintering, coking, and blast furnace iron-making, which require a large amount of energy and resources, resulting in high costs and being disadvantageous for 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 purification 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 gases at the same time. Finally, blast furnace iron-making generates a large amount of slag, which not only occupies a large amount of space resources but also causes serious pollution to the soil.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The embodiments of this application provide a metal manufacturing apparatus and method by electroreduction of molten salts, which can solve the problems of high process energy consumption and cost in existing metal manufacturing and being disadvantageous for environmental protection.

Means for Solving the Problems

[0004] To achieve the above object, the technical solutions of the embodiments of the present invention are shown below. In the first aspect, the embodiment of the present invention includes a reactor, a conductor, a power source, a gas filling and discharging mechanism, and a sealing mechanism. 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 to lay a reaction waiting substance and a molten salt substance in sequence 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. The positive electrode of the power source is electrically connected to the conductor, and the negative electrode of the power source is electrically connected to the bottom plate. The gas filling and discharging mechanism is arranged to continuously fill the reactor with a protective gas while exhausting exhaust gas, providing a metal manufacturing device by electroreduction of molten salt. According to the first aspect, in a possible implementation manner, the reactor includes a conductive bottom plate and a first insulating cylinder body. The first insulating cylinder body is 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 body. According to the first aspect, in a possible implementation manner, the reactor includes a conductive barrel and a second insulating cylinder body. The second insulating cylinder body is inserted into the conductive barrel, and the bottom surface abuts against the inner bottom surface of the conductive barrel. According to the first aspect, in a possible implementation manner, the metal manufacturing device by electroreduction of molten salt further includes a first conductive rod. One end of the first conductive rod is electrically connected to the conductor, and the other end passes through the sealing mechanism and is electrically connected to the positive electrode of the power source. In the second aspect, the embodiment of the present invention uses the above-mentioned metal manufacturing device by electroreduction of molten salt. The barrel cavity of the reactor is arranged to lay the reaction waiting substance and the molten salt substance in sequence from bottom to top. After heating the reactor until the molten salt substance melts, insert the conductor into the molten salt substance. Use the gas filling and discharging mechanism to continuously fill the reactor with a protective gas while exhausting exhaust gas, turn on the power source, and perform electroreduction of molten salt. After the reaction in the barrel cavity ends, turn off the power source, pour out the molten salt substance at the upper part of the barrel cavity, and take out the residue at the lower part. Provided is a method for manufacturing a metal by electroreduction of a molten salt, which includes obtaining a metal from the residue. According to a second aspect, in a possible implementation manner, obtaining a metal from the residue includes soaking the residue in ultrapure water multiple times to obtain powdered metal. According to a second aspect, in a possible implementation manner, obtaining a metal from the residue includes heating the residue and obtaining liquid or massive metal after reaching the melting point of the metal. According to a second aspect, in a possible implementation manner, the molten salt substance is one or more of chlorides or fluorides. According to a second aspect, in a possible implementation manner, the reaction waiting substance 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. The embodiments of the present invention provide an apparatus for manufacturing a metal by electroreduction of a molten salt. The apparatus includes a reactor, a conductor, a power source, a gas filling and discharging mechanism, and a sealing mechanism. The reactor is a barrel with a conductive bottom plate, an insulated peripheral wall, and one end open. The barrel cavity of the reactor is arranged to lay a reaction waiting substance and a molten salt substance in sequence from bottom to top. The conductor is used to insert the melted molten salt substance. The reactor and the conductor are provided inside the sealing mechanism. The power source is provided outside the sealing mechanism. The positive electrode of the power source is electrically connected to the conductor, and the negative electrode of the power source is electrically connected to the bottom plate. The gas filling and discharging mechanism is arranged to continuously fill the reactor with a protective gas while exhausting exhaust gas.

Effects of the Invention

[0005] In the metal manufacturing apparatus by electroreduction of molten salt provided by an embodiment of the present invention, a reactor and a conductor are provided inside a sealing mechanism, a power source is provided outside the sealing mechanism, a reaction waiting substance and a molten salt substance are laid in order from bottom to top in the barrel cavity of the reactor, a gas filling and discharging mechanism and a sealing mechanism are attached, the positive electrode of the power source is electrically connected to the conductor, and the negative electrode of the power source is electrically connected to the bottom plate of the reactor. After heating the reactor until the molten salt substance melts, the conductor is inserted into the molten salt substance. While exhausting exhaust gas by the gas filling and discharging mechanism, the reactor is continuously filled with a protective gas, the power source is turned on, and electroreduction of the molten salt is performed. When the reaction in the barrel cavity of the reactor is completed, the power source is turned off, the molten salt substance in the upper part of the barrel cavity is poured out, and the residue in the lower part is taken out. Finally, metal is obtained from the residue. In the metal manufacturing apparatus by electroreduction of molten salt provided by an embodiment of the present invention, the bottom plate of the reactor is conductive, the peripheral wall is insulated, the cathode of the electroreduction reaction of the molten salt is the conductive bottom plate of the reactor, and a reaction waiting substance and a molten salt substance are laid in order from bottom to top in the barrel cavity of the reactor. Since the reaction waiting substance only contacts and conducts with the conductive bottom plate of the reactor, when performing electroreduction of the molten salt, electrons move from the bottom upward, the current is transported in a certain direction, and the electroreduction process of the molten salt gradually proceeds from bottom to top, forming a "resistive" reaction structure, which can improve the utilization efficiency of the current. In the metal manufacturing apparatus by electroreduction of molten salt provided by an embodiment of the present application, when performing electroreduction of the molten salt, the process is simple, there is no need to consume a large amount of coke as a reducing agent and raw material, there is no need to consume a large amount of non-renewable coal resources, and there is no generation of a large amount of CO2, toxic gases and slag. The environmental pollution is small, high efficiency and low cost can be realized. It can perform electroreduction of molten salt at a relatively low operating temperature and can efficiently manufacture metal without relying on coke. The operation of the apparatus is relatively low, and the electroreduction process of the molten salt of the reaction waiting substance can be realized within a relatively low temperature range, which is advantageous for reducing the energy consumption of the heating process.

Brief Description of the Drawings

[0006] To more clearly explain the technical solutions of the embodiments of the present invention, the drawings necessary for the description of the embodiments of the present invention will be briefly introduced below. Obviously, 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 drawings without creative labor.

Figure 1

Figure 2

Figure 3

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Figure 6

Figure 7

Description of Reference Numerals

[0007] 1 - reactor, 11 - conductive bottom plate, 12 - first insulating cylinder, 13 - conductive barrel, 14 - second insulating cylinder, 2 - conductor, 3 - power source, 4 - gas filling and discharging mechanism, 41 - gas tank, 42 - gas filling pipe, 43 - exhaust pipe, 5 - sealing mechanism, 51 - furnace shell, 52 - heat insulation layer, 53 - furnace bed, 54 - furnace lid, 6 - reaction waiting substance, 61 - metal oxide, 62 - conductive agent, 7 - molten salt substance, 8 - first conductive rod, 9 - second conductive rod.

Embodiments for Carrying Out the Invention

[0008] The following will clearly and fully describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative labor shall fall within the protection scope of the present invention.

[0009] In the description of the embodiments of the present invention, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is merely for explaining and simplifying the description of the embodiments of the present invention, rather than indicating or implying that the shown device or element must be configured and operated in a specific orientation. It is for explaining and simplifying the embodiments of the present invention and should not be understood as limiting the present invention. The terms "first", "second", "third" are used only for the purpose of description and are not understood to indicate or imply relative importance. Furthermore, the terms "mounted", "connected", "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or an internal connection between two elements. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.

[0010] Referring to FIGS. 1 and 2, the present invention provides a metal manufacturing apparatus by electroreduction of molten salt, which includes a reactor 1, a conductor 2, a power source 3, a gas filling and discharging mechanism 4, and a sealing mechanism 5. The metal to be manufactured may be a pure metal or an alloy.

[0011] The reactor 1 is a barrel with a conductive bottom plate, an insulated peripheral wall, and one end open. The barrel cavity of the reactor 1 is arranged to lay the reaction waiting substance 6 and the molten salt substance 7 in order from bottom to top. The bottom plate of the reactor 1 may be made of metals such as stainless steel, iron, titanium, and conductive materials such as graphite. The peripheral wall can use high-temperature resistant insulating materials such as corundum and magnesium oxide. The molten salt substance 7 serves as the electrolyte for the electrolysis of the molten salt for electroreduction.

[0012] The conductor 2 is used to insert the molten salt substance 7 after melting. Among them, the conductor 2 can be made of graphite. The shape of the conductor 2 may be columnar, frustum-shaped, etc. In the embodiment of the present invention, a graphite rod is taken as an example. The outer wall of the rod shape is smooth, no adhesive substance adheres, and it is convenient for processing. Graphite has good electrical conductivity, good chemical stability, and is stable against most acids. It has a small linear expansion coefficient, low sensitivity to temperature changes, high thermal stability, and can withstand thermal shock well. The "affinity" between graphite and most media is extremely small, the surface of the graphite rod is not easily soiled, and it is not easily affected by conductivity. The processing performance of graphite is good. Except that it cannot be rolled or forged, various machining can be carried out.

[0013] The reactor 1 and the conductor 2 are provided inside the sealing mechanism 5, and the power supply 3 is provided outside the sealing mechanism 5. As shown in FIGS. 1 and 2, this sealing mechanism 5 may be a heating furnace or other closed body. When the sealing mechanism 5 is a heating furnace, this heating furnace includes a furnace shell 51, a heat insulation layer 52, a furnace bed 53, and a furnace lid 54. The reactor 1 and the conductor 2 are provided inside the furnace bed 53. When the sealing mechanism 5 is a closed body, members such as the reactor 1 and the conductor 2 are pre-mounted, and when the device needs to be used, the whole device can be arranged when in use.

[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 exhausting mechanism 4 is arranged to continuously fill the reactor 1 with a protective gas while exhausting the exhaust gas. Specifically, as shown in FIGS. 1 and 2, the gas filling and exhausting 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 and extends into the interior of the sealing mechanism 5 to continuously fill the reactor 1 with the protective gas. The exhaust pipe 43 is inserted into the upper cover of the sealing mechanism 5 to exhaust the exhaust gas. The gas filling and exhausting mechanism 4 fills the protective gas according to the actual demand. For example, the protective gas filled in the present application is argon gas, and this gas tank 41 is an argon gas tank.

[0015] In the metal manufacturing apparatus by electroreduction of molten salt provided by the embodiments of the present invention, a reactor 1 and a conductor 2 are provided inside a sealing mechanism 5, a power source 3 is provided outside the sealing mechanism 5, a reaction waiting substance 6 and a molten salt substance 7 are laid in order from bottom to top in the barrel cavity of the reactor 1, a gas filling and discharging mechanism 4 and a sealing mechanism 5 are installed, the positive electrode of the power source 3 is electrically connected to the conductor 2, and the negative electrode of the power source 3 is electrically connected to the bottom plate of the reactor 1. After heating the reactor 1 until the molten salt substance 7 melts, the conductor 2 is inserted into the molten salt substance 7. While exhausting exhaust gas by the gas filling and discharging mechanism 4, the reactor 1 is continuously filled with a protective gas. The power source 3 is turned on to perform electroreduction of the molten salt. When the reaction in the barrel cavity of the reactor 1 is completed, the power source 3 is turned off, the molten salt substance 7 at the upper part of the barrel cavity is poured out, and the residue at the lower part is taken out. Finally, metal is obtained from the residue. In the metal manufacturing apparatus by electroreduction of molten salt provided by the embodiments of the present invention, the bottom plate of the reactor 1 is conductive, the peripheral wall is insulated, the cathode of the electroreduction reaction of the molten salt is the conductive bottom plate of the reactor 1, and the reaction waiting substance 6 and the molten salt substance 7 are laid in order from bottom to top in the barrel cavity of the reactor 1. Since the reaction waiting substance 6 only contacts and conducts with the conductive bottom plate of the reactor 1, when performing electroreduction of the molten salt, electrons move from the bottom upwards, the current is transported in a certain direction, the electroreduction process of the molten salt gradually proceeds from bottom to top, forming a "resistive" reaction structure, and the utilization efficiency of the current can be increased. In the metal manufacturing apparatus by electroreduction of molten salt provided by the embodiments of the present application, when performing electroreduction of the molten salt, the process is simple, there is no need to consume a large amount of coke as a reducing agent and raw material, there is no need to consume a large amount of non-renewable coal resources, and there is no generation of a large amount of CO2, toxic gases and slag. The environmental pollution is small, high efficiency and low cost can be realized. It can perform electroreduction of molten salt at a relatively low operating temperature and can efficiently manufacture metal without relying on coke. The operation of the apparatus is relatively low, and the electroreduction process of the molten salt of the reaction waiting substance 6 can be realized within a relatively low temperature range, which is advantageous for reducing the energy consumption in the heating process. As shown in FIG. 1, the reactor 1 includes a conductive bottom plate 11 and a first insulating cylinder 12. Since the first insulating cylinder 12 is provided on the conductive bottom plate 11, 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 a low cost.

[0016] Furthermore, since the outer diameter of the conductive bottom plate 11 is greater than or equal to the outer diameter of the first insulating cylinder 12, it is possible to ensure the conductivity of the entire bottom of the barrel cavity of the reactor 1, and the effect is better when the device is electrochemically reduced in molten salt. In addition, it is possible to facilitate 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 includes 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 into the barrel cavity of the reactor 1 from above. When the filled protective gas is a gas heavier in mass than the exhaust gas such as argon gas, the protective gas continuously flows downward, and the exhaust gas in the barrel cavity can be more sufficiently and quickly removed. However, the gas filling pipe 42 of the gas filling and discharging mechanism 4 extends into the barrel cavity of the reactor 1 from above, and the protective gas can fill the barrel cavity of the reactor 1 more quickly.

[0018] Preferably, as shown in FIG. 2, the reactor 1 includes a conductive barrel 13 and a second insulating cylinder 14. The second insulating cylinder 14 is inserted into the conductive barrel 13, and the bottom surface abuts against the inner bottom surface of the conductive barrel 13. At this time, the bottom surface of the conductive barrel 13 is conductive as the bottom plate of the reactor 1, and the second insulating cylinder 14 is insulated as the peripheral wall of the reactor 1. The reactor 1 provided by the embodiment of the present application has a simple structure and is easy to implement. If the existing graphite crucible is used as the conductive barrel 13, the cost can be saved. In addition, the reactor 1 includes the conductive barrel 13, which makes it easy to electrically connect the negative electrode of the power supply 3 to the bottom plate of the reactor 1. Since the conductive barrel 13 itself is entirely conductive and the second insulating cylinder 14 is inserted into the conductive barrel 13, the negative electrode of the power supply 3 can be electrically connected to any position of the conductive barrel 13, and the negative electrode of the power supply 3 can be electrically connected to the bottom plate of the reactor 1 without affecting the second insulating cylinder 14.

[0019] Furthermore, when the reactor 1 includes the conductive barrel 13 and the second insulating cylinder 14, after the second insulating cylinder 14 is inserted into the conductive barrel 13, the outer wall height of the conductive barrel 13 is lower than the height of the second insulating cylinder 14. Therefore, an electrical insulation layer is formed at the opening of the reactor 1, which can prevent the influence on the electroreduction of the molten salt.

[0020] As shown in FIG. 2, when the reactor 1 includes the conductive barrel 13 and the second insulating cylinder 14, due to the installation of the conductive barrel 13, the gas filling pipe 42 of the gas filling and discharging mechanism 4 extends into the gap between the inner cavity of the sealing mechanism 5 and the conductive barrel 13. Therefore, the installation of the conductive barrel 13 and the second insulating cylinder 14 and the installation into the sealing mechanism 5 can be facilitated.

[0021] As shown in FIGS. 1 and 2, the metal manufacturing apparatus by electroreduction of molten salt includes the 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 source 3. This first conductive rod 8 may be a steel rod. The steel rod material is easy to obtain and has a low cost. The conductor 2 is used to insert the molten salt substance 7 after melting. 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 source 3. That is, since the first conductive rod 8 is drilled through the upper cover of the sealing mechanism 5, the conductor 2 can be easily fixed and is not easy to fall. At the same time, the relative position between the conductor 2 and the molten salt substance 7 is easy to identify, and it does not affect the electrical connection of the conductor 2 to the power source 3. Of course, the conductor 2 is electrically connected to the power source 3 directly by a wire.

[0022] Furthermore, the metal production apparatus by the electroreduction of molten salt also 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. By installing the second conductive rod 9, it is easier to electrically connect the negative electrode of the power supply 3 to the bottom plate, the rod shape is fixed, and the installation and attachment can be improved. 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 equal to or greater than the outer diameter of the first insulating cylinder 12, making it easier to electrically connect the second conductive rod 9 to the conductive bottom plate 11, and only the outer edge of the conductive bottom plate 11 needs to be brought into contact with the second conductive rod 9. By installing the second insulating cylinder 14, it is ensured 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 conducting wire. Also, since the apparatus needs to be heated when the electroreduction of molten salt is performed, the first conductive rod 8 and the second conductive rod 9 have heat resistance.

[0023] Another embodiment of the present invention provides a method for producing metal by electroreduction of molten salt, which uses the above metal production apparatus by electroreduction of molten salt and includes steps 301 - 305.

[0024] Step 301: Lay the reaction waiting substance 6 and the molten salt substance 7 in the barrel cavity of the reactor 1 in order from bottom to top. Among them, the molten salt substance 7 is one or more of chlorides or fluorides. Preferably, the molten salt substance 7 is a variety 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 for heating the molten salt substance 7 in the process of electroreduction of molten salt by the apparatus is lowered, and electroreduction in the temperature range of 600°C - 1200°C of the molten salt substance 7 can be realized. For example, this molten salt substance 7 is composed of one or more of NaCl, KCl, CaCl2, NaF, KF, CaF2, etc.

[0025] The reaction waiting substance 6 includes a metal oxide 61 and a conductive agent 62. Since the conductive agent 62 is a part of the component of the metal to be produced, when the reaction of the reaction waiting substance 6 is completed, there is no need to additionally remove the conductive agent 62, and the conductive agent 62 also becomes the metal to be produced.

[0026] The conductive agent 62 functions as a conductive medium and an induction medium for the metal oxide 61 in the electroreduction process of the molten salt. As a conductive medium, the conductive agent 62 is doped between the powder particles of the metal oxide 61, and the conductive agent 62 is uniformly arranged between the powder particles of the metal oxide 61, increasing the conductivity of the reaction waiting substance 6, increasing the conductivity of the reaction waiting substance 6, improving the current conduction and the reaction power of the electrochemical reaction, enhancing the reaction effect of the electroreduction of the molten salt, eliminating the need to use coke compared with the prior art, and significantly reducing energy consumption and environmental pollution. As an induction medium, the conductive agent 62 can be used to provide auxiliary internal heating when inductively heating the device. The metal oxide 61 in the reaction waiting substance 6 is in powder form and can perform electroreduction of the molten salt, without the need for crimping, shortening the time for producing the metal, and having a large specific oxygen area of the metal oxide 61 and a high reaction rate. For example, the conductive agent 62 can be various biomass toners such as metal powders of Al, Fe, Ti, etc. Specifically, a mixture of the metal oxide 61 and the conductive agent 62 is laid at the bottom of the reactor 1, compacted, and then the molten salt substance 7 is arranged and laid on it to form the structural characteristics of the lower reaction waiting substance 6 and the upper molten salt substance 7.

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

[0028] Step 303: The gas filling and discharging mechanism 4 continues to fill the reactor 1 with protective gas, and while exhaust gas is discharged, the power supply 3 is turned on to perform electrical reduction of the molten salt. For example, argon gas from an argon gas tank is continuously filled into the reactor 1 through the gas filling pipe 42, and exhaust gas such as air is discharged through the exhaust pipe 43, and the exhaust gas overflows from the molten salt material 7 due to the buoyancy effect. 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 electrical reduction is performed at a constant current or voltage.

[0029] Step 304: When the reaction in the barrel cavity is completed, the power source 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 taken out.

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

[0031] Further, Step 305: obtaining a metal from the residue includes: The residue was immersed in ultrapure water several times to obtain powdered metal. Specifically, after cooling the solid residue at the bottom, the residue obtained after electrolytic reduction of the molten salt was immersed in ultrapure water to remove the molten salt material 7 remaining in the residue. This process was repeated 3-4 times, washed with anhydrous alcohol, and dried to obtain powdered metal. Preferably, Step 305: Obtaining metal from the residue comprises: The residue is heated to a metal melting point, and then liquid or lump metal is obtained. For example, the residue is induction-heated to melt, and the molten salt material 7 remaining in the residue is volatilized and collected, and when the metal melting point is reached, liquid or lump metal is obtained.

[0032] By repeating the above steps 301 to 305, the metal oxide 61 can be continuously reduced to metal, and the poured out molten salt material 7 can be repeatedly used, thereby avoiding the defect of generating a large amount of slag in the conventional technology such as the iron making process.

[0033] The metal manufacturing method by electroreduction of molten salt provided by the embodiments of the present application can perform electroreduction of molten salt, has few process steps, and can reduce the manufacturing cost of metal.

[0034] Specific embodiments of the metal manufacturing apparatus and method by electroreduction of molten salt provided by the embodiments of the present application are as follows.

[0035] Example 1 Manufacture of metallic iron by electroreduction of molten salt Insert a corundum tube into a conductive crucible to obtain reactor 1. 20 g of Fe3O4 and 0.8 g of toner mixture were laid and compressed at the bottom of reactor 1 as reaction waiting substances 6. Then, 160 g of a molten salt substance 7 in which NaCl and NaF with a molar ratio of 1:1 were mixed was laid on top. Reactor 1 was placed in a heating furnace and heated. After the temperature rose to 800 °C, the electroreduction process of the molten salt was started. Argon gas was continuously passed through the heating furnace by the gas filling and discharging mechanism 4 for protection to prevent oxidation of the metal at high temperature.

[0036] Connect the connection wires of power supply 3 (Guowei PSM-3004) to the cathode (bottom of reactor 1) and anode (graphite rod) of the device respectively. The electroreduction process of the molten salt was carried out for 7.0 h under a current of 2.0 A, and all Fe3O4 was reduced to iron metal.

[0037] When the reaction in the barrel cavity of reactor 1 was completed, power supply 3 was turned off, the crucible was taken out, and the molten salt substance 7 was poured out and left for recycling. Two methods can be used to separate the remaining molten salt substance 7 from the metallic iron. (1) Water washing method: After the crucible was cooled, the residue in the crucible was immersed and washed in ultrapure water 5-6 times to remove the remaining molten salt substance 7. It was further washed 2-3 times with absolute ethanol, and after drying, powdery pure metal was obtained as shown in Figure 3. (2) Heating method: The residue after electroreduction was heated in an induction furnace in the temperature range of 1000 °C to 1200 °C to volatilize and recover the molten salt substance 7, and massive metallic iron was obtained as shown in Figure 4. The results of XRD detection of the metal obtained by electroreduction of the molten salt are shown in Figure 5. The substances after electroreduction of the molten salt are all pure iron metal except for a small amount of Fe and C compounds.

[0038] Example 2: Production of Titanium Aluminum Alloy by Electroreduction 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 at the upper end of the graphite crucible, a wire with a polished bright length of 1.5 m was inserted into this hole, the mouth of the hole was sealed with high-temperature AB rubber, and after standing at room temperature for 12 h, it was transferred to a tubular furnace, kept warm at 100 °C and 150 °C for 2 h respectively, and then cooled to room temperature according to the furnace and taken out.

[0039] 20 g of TiO2 was laid at the bottom of reactor 1 and compacted. The surface of 29.3 g of Al ingot was polished smoothly and placed on the TiO2 sample in reactor 1. Then, 7 of the dried Na3AlF6 molten salt substance was laid on the Al ingot. Reactor 1 was installed in a heating furnace and heated until the temperature rose to 1150 °C, and argon gas was continuously passed through the furnace to protect it from preventing the metal from oxidizing at high temperature. The connection wires of power supply 3 (Guwei PSM-3004) were connected to the cathode (bottom of the graphite crucible) and anode (graphite rod) of the device respectively.

[0040] An electroreduction process was carried out for 60 min under a voltage of 3.0 V to reduce all TiO2 to Al3Ti. After the electroreduction of the molten salt was completed, power supply 3 was turned off, the graphite crucible was taken out, the molten salt substance 7 was poured out and left for recycling. After the crucible was cooled, the residue in the crucible was immersed in ultrapure water and washed 5-6 times to remove the remaining molten salt substance 7. Then, the product was put into 0.1 mol / L dilute hydrochloric acid for further impurity removal, and finally washed 2-3 times with absolute ethanol and sealed and stored after drying. Here, the metal after the electroreduction of the molten salt is gray as shown in Figure 6, and has a metallic luster after polishing. The XRD detection result of this metal is that only the Al3Ti phase exists as shown in Figure 7, without other impurities, and its diffraction peak, compared with the standard card, did not generate an offset.

[0041] Example 3: Cost Analysis of the Production of Metallic Iron by Electroreduction of Molten Salt

[0042] 1. Main costs (1) Raw material costs: The raw materials are iron ore powder and biomass charcoal. Among them, the main component used at the laboratory stage is iron ore powder of Fe3O4, and the added carbon source is biomass charcoal. In industry, it can be replaced by semi-coke with a lower cost than metallurgical coke. Through the data of the steel union, it is clear that the market prices of iron ore powder and semi-coke are about 769 yuan / ton and 1616.67 yuan / ton respectively.

[0043] (2) Power consumption cost in the molten salt electrolytic reduction process Taking the example of electrolyzing at a constant current of 2.0 A for 7 h, by calculating from the voltage curve of the electroreduction process of molten salt, the power consumption is about 28.1 W·h, that is, 0.0281 degrees of electricity can be obtained. According to the industrial electricity price of 0.5 yuan / degree, the power consumption in this process is 0.01405 yuan.

[0044] 2. Usage of raw materials and electricity consumption when producing 1 ton of reduced iron powder During the experiment, 20 g of Fe3O4 (iron ore powder) and 0.8 g of biomass charcoal (semi-coke) were electrolyzed at a constant current of 2.0 A for 7 h, and 10.04 g of iron was recovered. The power consumption in this process calculated above was 0.0281 degrees of electricity (0.5 yuan / degree, that is, 0.01405 yuan). When scaled up in proportion, it can be calculated that 2800 degrees of electricity are required to produce 1 ton of iron. Calculated at the industrial electricity price of 0.5 yuan / degree, the electricity usage cost for producing 1 ton of iron is about 1400 yuan.

[0045] 3. Main costs for producing 1 ton of reduced iron powder To produce 1 ton of iron, 1.992 tons of iron ore powder, 0.07968 tons of semi-coke, and 2800 degrees of electricity are required. Therefore, the cost of producing 1 ton of iron using this technology can be calculated to be about 3060.65 yuan. Compared with the conventional technology, the cost of producing 1 ton of iron has been significantly reduced. Each embodiment in this specification is described progressively. For the same or similar parts among the embodiments, reference can be made to each other, and each embodiment focuses on explaining the differences from other embodiments.

[0046] The above embodiments are not limited to the present application and are only used for explaining the technical solutions of the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art can modify the technical solutions described in the above embodiments or equally replace some or all of their technical features, and these corrections or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the present application.

Claims

1. A metal manufacturing apparatus by electroreduction of molten salt, comprising a reactor, a conductor, a power source, a gas filling and discharging mechanism, and a sealing mechanism, wherein the reactor is a barrel with a conductive bottom plate, an insulated peripheral wall, and one end open, and the barrel cavity of the reactor is arranged to lay a substance waiting for reaction and a molten salt substance in order from bottom to top, the conductor is used to insert the melted molten salt substance, the reactor and the conductor are provided inside the sealing mechanism, and the power source is provided outside the sealing mechanism, the positive electrode of the power source is electrically connected to the conductor, and the negative electrode of the power source is electrically connected to the bottom plate, the gas filling and discharging mechanism is arranged to continuously fill the reactor with a protective gas while exhausting exhaust gas, A metal manufacturing apparatus by electroreduction of molten salt, characterized by the above.

2. The reactor includes a conductive bottom plate and a first insulating cylinder body, and the first insulating cylinder body is provided on the conductive bottom plate, A metal manufacturing apparatus by electroreduction of molten salt according to Claim 1, characterized by the above.

3. The outer diameter of the conductive bottom plate is greater than or equal to the outer diameter of the first insulating cylinder body, A metal manufacturing apparatus by electroreduction of molten salt according to Claim 2, characterized by the above.

4. The reactor includes a conductive barrel and a second insulating cylinder body, the second insulating cylinder body is inserted into the conductive barrel, and the bottom surface abuts against the inner bottom surface of the conductive barrel, A metal manufacturing apparatus by electroreduction of molten salt according to Claim 1, characterized by the above.

5. Further including a first conductive rod, one end of the first conductive rod is electrically connected to the conductor, and the other end passes through the sealing mechanism and is electrically connected to the positive electrode of the power source, A metal manufacturing apparatus by electroreduction of molten salt according to Claim 1, characterized by the above.

6. A metal manufacturing method by electroreduction of molten salt using the metal manufacturing apparatus by electroreduction of molten salt according to any one of Claims 1 to 5, comprising laying the substance waiting for reaction and the molten salt substance in the barrel cavity of the reactor in order from bottom to top, heating the reactor until the molten salt substance melts, and then inserting the conductor into the molten salt substance, continuously filling the reactor with a protective gas while exhausting exhaust gas by the gas filling and discharging mechanism, and turning on the power source to perform electroreduction of molten salt, The reaction in the barrel cavity is completed, the power supply is turned off, the molten salt substance above the barrel cavity is poured out, and the residue below is taken out, obtaining a metal from the residue, characterized by a method for producing a metal by electroreduction of a molten salt.

7. Obtaining a metal from the residue includes soaking the residue in ultrapure water multiple times to obtain powdery metal, characterized by the method for producing a metal by electroreduction of a molten salt according to claim 6.

8. Obtaining a metal from the residue includes heating the residue and obtaining liquid or massive metal after reaching the melting point of the metal, characterized by the method for producing a metal by electroreduction of a molten salt according to claim 6.

9. The molten salt substance is one or more of chlorides or fluorides, characterized by the method for producing a metal by electroreduction of a molten salt according to claim 6.

10. The reaction waiting substance includes a metal oxide and a conductive agent, characterized by the method for producing a metal by electroreduction of a molten salt according to claim 6.

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