Method and device for selectively recovering metal

Abstract

The invention discloses a method and device for selectively recycling metal, and the method comprises the steps that a metal mixture and a chlorination reagent are mixed to obtain a first mixture, and metal elements in the metal mixture comprise at least one of gallium, indium and tantalum; the first mixture is heated to obtain a second mixture, and the second mixture comprises chlorides corresponding to the metal elements; and carrying out separation treatment on the second mixture to obtain the purified compound corresponding to the metal element. According to the method, the target metal is converted into the corresponding metal chloride based on temperature control of thermodynamic difference or dynamic difference, so that the target metal to be recycled is selectively separated from other substances in the metal mixture, and collection and treatment of the target metal are realized. The method has the advantages of high selectivity, higher yield, lower energy consumption and more types of applicable metal mixture raw materials.

Description

Technical Field

[0001] This application relates to the field of metal recycling, and specifically, to methods and apparatuses for selectively recycling metals. Background Art

[0002] Among metal materials, strategic critical metals are a type of metals that are used in relatively small amounts but play a key role in national defense, military industry, high-tech development, etc. The vast majority of them are rare metals, including scattered metals, rare and precious metals, rare earth metals, etc. These metals play an irreplaceable role in fields such as electronic devices and new energy systems. For example, scattered metals such as gallium and indium have important uses in semiconductors and displays, rare earth metals play a key role in electric vehicles and wind power generation as strong magnetic materials, and rare and precious metals such as platinum and palladium have an irreplaceable role in hydrogen energy fields such as electrolyzers and fuel cells. Since the reserves of the above strategic critical metals are limited, it is of great significance for the sustainable supply and utilization of resources to analyze these key metal materials according to their properties from metal mixtures, metal-nonmetal mixture systems or waste, and select target metals by appropriate methods for selective recovery or separation. Summary of the Invention

[0003] In a first aspect of this application, a method for selectively recycling metals is proposed, including: mixing a metal mixture with a chlorinating reagent to obtain a first mixture, wherein the metal elements in the metal mixture include at least one of gallium, indium, and tantalum; performing a heat treatment on the first mixture to obtain a second mixture, the second mixture including chlorides corresponding to the metal elements, wherein the temperature of the heat treatment is 200°C - 2500°C, and the time of the heat treatment is 5 s - 5 min; performing a separation treatment on the second mixture to obtain a purified compound corresponding to the metal element.

[0004] The method for selectively recycling metals proposed in this application, based on temperature control of thermodynamic differences or kinetic differences, converts the target metal (at least one of gallium, indium, and tantalum) into the corresponding metal chloride, enabling selective separation of the target metal to be recycled from other substances in the metal mixture, thereby achieving the collection and treatment of the target metal.

[0005] In some embodiments, the metal mixture includes at least one of electronic waste, ore, tailings, alloy, metal oxide, metal sulfide, and metal nitride. Thus, the method proposed in this application can selectively extract and recycle the target metal from metal mixtures with greater utilization difficulty and more complex compositions.

[0006] In some embodiments, the chlorination reagent includes a solid chlorination reagent and / or a gaseous chlorination reagent, wherein the solid chlorination reagent includes at least one of metal chlorides, non-metal chlorides, and chlorine-containing polymers, and the gaseous chlorination reagent includes at least one of chlorine and hydrogen chloride. Thus, the method proposed in the present application can use a variety of chlorine-containing mixtures or chlorine-containing compounds with complex compositions as chlorination reagents, make full use of the chlorine element in the chlorination reagent for chlorination reactions, and select chlorination reagents with lower costs and easier access, which is beneficial to reducing the cost of the overall process for recovering target metals.

[0007] In some embodiments, the heating rate of the heat treatment is 1000 °C / s - 5000 °C / s. Thus, the temperature required for the chlorination reaction of the target metal can be reached in a relatively short time.

[0008] In some embodiments, the cooling rate of the heat treatment is 100 °C / s - 500 °C / s. Thus, the control of the reaction temperature can be achieved in a relatively short time.

[0009] In some embodiments, the heat treatment includes pulsed discharge heat treatment. Thus, the heat treatment can be carried out efficiently, providing the reaction temperature, heating rate, and cooling rate required in the process of recovering the target metal.

[0010] In some embodiments, heating the first mixture includes placing the first mixture on a heating element, where the resistivity of the heating element is 1 mΩ·cm - 10 mΩ·cm, and the voltage of the heating element is 20 V - 180 V. Thus, through the electrothermal effect occurring on the heating element, the required reaction temperature can be quickly provided.

[0011] In some embodiments, the heating element includes at least one of a metal conductor and a carbon fiber product, wherein the carbon fiber product includes at least one of carbon paper, carbon cloth, carbon felt, and graphite sheet. Thus, the heating element can convert electrical energy into heat energy with a relatively high conversion efficiency.

[0012] In some embodiments, before mixing the metal mixture with the chlorination reagent, it further includes: roasting the electronic waste to obtain the metal mixture, wherein the temperature of the roasting treatment is 500 °C - 1000 °C. Thus, organic substances, volatile substances, etc. in the metal mixture can be separated from the metal mixture through the roasting treatment.

[0013] In some embodiments, the separation treatment includes at least one of evaporation separation, dissolution-filtration separation, and magnetic separation. Thus, the chloride corresponding to the target metal can be separated from other impurities by using the differences in vapor pressure, solubility, and magnetism.

[0014] In the second aspect of the present application, a device for selectively recovering metals is proposed, and the device for selectively recovering metals uses the method for selectively recovering metals to recover metals.

[0015] The device for selectively recovering metals proposed in the present application can process metal mixtures with a wide range of sources, has good recovery selectivity, and has low production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, where:

[0017] Figure 1 is a schematic diagram of the electrothermal chlorination reaction process in an embodiment of the present application;

[0018] Figure 2 is the heating rate and cooling rate in an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of the electrothermal chlorination reaction device in an embodiment of the present application;

[0020] Figure 4 is the critical temperature of the electrothermal chlorination reaction of metal oxides;

[0021] Figure 5 is a typical temperature-time curve;

[0022] Figure 6 is the maximum value of the temperature under different voltage inputs;

[0023] Figure 7 is a photo of the heating element before and during power-on in an embodiment of the present application;

[0024] Figure 8 is the boiling point of metal chlorides;

[0025] Figure 9 is a schematic diagram of the process of recovering indium metal in Example 1 of the present application;

[0026] Figure 10 is the relationship between the recovery purity of indium metal and the input reaction voltage in Example 1 of the present application;

[0027] Figure 11 is the relationship between the recovery rate of indium metal and the input reaction voltage in Example 1 of the present application;

[0028] Figure 12 is the XRD pattern of the indium chloride product in Example 1 of the present application;

[0029] Figure 13Schematic diagram for the separation and recovery of gallium metal in Example 2 of this application;

[0030] Figure 14 Relationship between the recovery purity of gallium metal and the input of reaction voltage in Example 2 of this application;

[0031] Figure 15 Relationship between the recovery rate of gallium metal and the input of reaction voltage in Example 2 of this application;

[0032] Figure 16 XRD pattern of the gallium oxide product in Example 2 of this application;

[0033] Figure 17 Schematic diagram for the separation and recovery of tantalum metal in Example 3 of this application;

[0034] Figure 18 Relationship between the recovery purity of tantalum metal and the reaction conditions in Example 3 of this application;

[0035] Figure 19 Relationship between the recovery rate of tantalum metal and the reaction conditions in Example 3 of this application;

[0036] Figure 20 XRD pattern of the tantalum oxide product in Example 3 of this application. Detailed implementation manners

[0037] The embodiments of the present application are described in detail below. The examples of the embodiments are shown in the drawings, but there may be cases where unnecessary details are omitted. For example, there may be cases where the detailed description of well-known matters is omitted and the repeated description of actually identical structures is omitted. This is to avoid the following description from becoming unnecessarily long and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0038] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; unless otherwise stated, the numerical values of the various parameters mentioned in this application can be measured by various common measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0039] The terms "comprising" and "having" and any variations thereof in the specification and claims of this application are open expressions, that is, they include the content specified in this application, but do not exclude other aspects.

[0040] In the description of this application, all the numbers disclosed herein are approximate values, whether or not words such as "about" or "approximately" are used. There may be a difference of less than 10% in the numerical value of each number, or a reasonable difference considered by those skilled in the art, such as a difference of 1%, 2%, 3%, 4%, or 5%.

[0041] The "ranges" disclosed in this application are defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In this application, unless otherwise specified, the numerical range "a - b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0 - 5" represents that all real numbers between "0 - 5" have been fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when it is stated that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0042] If there is no special instruction, all the embodiments and optional embodiments of this application can be combined with each other to form new technical solutions.

[0043] If there is no special instruction, all the technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0044] When recovering gallium metal in rare metals, indium metal, and tantalum metal in refractory rare metals as target metals, there are many problems in the recovery schemes in related technologies. For example, if separation and recovery are carried out through traditional hydrometallurgical processes, the entire process involves acid leaching or alkali leaching processes with a large amount of solvent consumption, and multiple liquid-liquid separation processes, such as solvent extraction. Hydrometallurgy has good selectivity, but it requires a large amount of water and chemicals, resulting in the generation of a large amount of secondary waste liquid. Traditional pyrometallurgical processes have low selectivity for different metals, causing the accumulation of alloy elements in the obtained products, which can further lead to metal degradation. Specific metals can also be extracted and separated through chlorination metallurgy processes, but there are a large amount of waste molten salts generated during the smelting process, and the recovery and treatment of waste molten salts are difficult. The method for selectively recovering metals proposed in this application produces less harmful waste during the recovery process, has a higher productivity, consumes less energy, and this method is applicable to a variety of metal mixture raw materials, and has a wide application range in metal recovery and separation.

[0045] In a first aspect of the present application, the present application proposes a method for selectively recovering metals, including: mixing a metal mixture with a chlorinating reagent to obtain a first mixture, wherein the metal elements in the metal mixture include at least one of gallium, indium, and tantalum; heating the first mixture to obtain a second mixture, the second mixture includes chlorides corresponding to the metal elements, wherein the temperature of the heating treatment is 200°C - 2500°C, and the time of the heating treatment is 5s - 5min; separating the second mixture to obtain the purified compound corresponding to the metal element.

[0046] The method for selectively recovering metals proposed in this application refers to Figure 1, by analyzing the metals and other substances contained in the metal mixture where the target metal to be recycled is located, a separation strategy for extracting the target metal from the metal mixture is designed. Based on temperature control based on thermodynamic differences or temperature control based on kinetic differences, by causing the target metal (at least one of gallium, indium, tantalum) to undergo a chlorination reaction with a chlorination reagent, within the temperature range and heating time range of the aforementioned heat treatment, based on the analysis of the thermodynamics of the chlorination reaction, a heat treatment within the corresponding temperature range is set and carried out, thereby converting the target metal into the corresponding metal chloride. Since the physical and chemical properties of the target metal change after it changes from its state in the metal mixture to the corresponding chloride. According to the property characteristics of the mixed system obtained after heat treatment of the metal mixture, such as vapor pressure difference, solubility difference, magnetic difference, the target metal to be recycled can be selectively separated from other substances in the metal mixture, so as to further collect and process the target metal. Since the chloride of the target metal can further undergo chemical changes such as oxidation reaction and decomposition reaction, the finally obtained can be a compound of the target metal with relatively high purity.

[0047] In some embodiments, the metal mixture includes at least one of electronic waste, ore, tailings, alloy, metal oxide, metal sulfide, metal nitride. Thus, the method proposed in this application can selectively extract and recycle the target metal from metal mixtures with high utilization difficulty and complex composition, has a wide range of applications, and can process metal mixtures from many types of sources.

[0048] In some embodiments, the chlorination reagent includes a solid chlorination reagent and / or a gaseous chlorination reagent, wherein the solid chlorination reagent includes at least one of metal chlorides, non-metal chlorides, and chlorine-containing polymers, and the gaseous chlorination reagent includes at least one of chlorine and hydrogen chloride. Thus, the method proposed in this application can use a variety of chlorine-containing mixtures or chlorine-containing compounds with complex substance compositions as chlorination reagents, make full use of the chlorine element in the chlorination reagent for the chlorination reaction, and can select chlorination reagents with lower cost and easier access, which is beneficial to reducing the cost of the overall process of recycling the target metal.

[0049] In some embodiments, the heating rate of the heat treatment is 1000 °C / s - 5000 °C / s. Thus, referring to Figure 2 , the temperature required for the chlorination reaction of the target metal can be reached in a relatively short time, and then the reaction progress can be shortened to achieve a shorter process time.

[0050] In some embodiments, the cooling rate of the heat treatment is 100 °C / s - 500 °C / s. Thus, referring to Figure 2, the reaction temperature can be controlled in a relatively short time, which is beneficial to shortening the non-reaction time and improving the efficiency of the overall process.

[0051] In some embodiments, the heat treatment includes pulsed discharge heat treatment. Thus, by converting electrical energy into heat energy, the heat treatment can be efficiently carried out to provide the reaction temperature, heating rate, and cooling rate required in the process of recovering the target metal. Moreover, by providing the temperature conditions required for the chlorination reaction through electric heating, this method has a faster heating rate, cooling rate, and a larger temperature adjustable range, can achieve higher economic benefits, and can adapt to metal mixtures from a wider range of sources.

[0052] In some embodiments, heating the first mixture includes placing the first mixture on a heating element, the resistivity of the heating element is 1 mΩ·cm - 10 mΩ·cm, and the voltage of the heating element is 20 V - 180 V. Thus, referring to Figure 3 and Figure 4 , the metal mixture can be placed on the heating element. In the reaction chamber, the flow and supply of the gaseous chlorinating reagent in the reaction chamber are maintained through a vacuum pump, and the gaseous reactants can also be collected. A power control system and a power supply system are used to control the energization time and voltage of the heating element. Through the electrothermal effect occurring on the heating element, the required chlorination reaction temperature is quickly provided. Further, referring to Figure 5 and Figure 6 , as the voltage increases, the maximum temperature that can be reached increases. By adjusting the magnitude of the voltage, the temperature of the heating element and the maximum temperature that the heating element can reach can be changed to meet the requirements of different reaction temperatures.

[0053] In some embodiments, the heating element includes at least one of a metal conductor and a carbon fiber product, wherein the carbon fiber product includes at least one of carbon paper, carbon cloth, carbon felt, and graphite sheet. Thus, referring to Figure 7 , the materials of the aforementioned heating element have appropriate thermal conductivity and electrical conductivity, and the heating element can convert electrical energy into heat energy with a relatively high conversion efficiency.

[0054] In some embodiments, before mixing the metal mixture with the chlorinating reagent, it further includes: roasting the electronic waste to obtain the metal mixture, wherein the temperature of the roasting treatment is 500°C - 1000°C. Thus, the organic substances, volatile substances, etc. in the metal mixture can be separated from the metal mixture through the roasting treatment, reducing the possible side reactions in the metal mixture to improve the efficiency of the chlorination reaction.

[0055] In some embodiments, the separation process includes at least one of evaporation separation, dissolution-filtration separation, and magnetic separation. Thus, after the heat treatment, the chloride corresponding to the target metal can be obtained. However, due to the different combinations of the metal mixture, the chloride corresponding to the target metal may be mixed with other compounds. Therefore, the chloride corresponding to the target metal can be separated by using the difference in vapor pressure (refer to Figure 8 , with the y-axis being temperature and different elements distributed along the x-axis), solubility difference, and magnetic difference to improve its purity.

[0056] In the second aspect of the present application, the present application provides a device for selectively recovering metals, and the device for selectively recovering metals uses the method for selectively recovering metals to recover metals.

[0057] The device for selectively recovering metals proposed in the present application can process metal mixtures with a wide range of sources, has good recovery selectivity, and has a low production cost.

[0058] The solution of the present application will be described below through specific embodiments. It should be noted that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those without specific technologies or conditions indicated in the embodiments, they shall be carried out according to the technologies or conditions described in the literature in the art or according to the product specifications. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial procurement.

[0059] Example 1

[0060] Target metal: indium metal

[0061] The transparent electrode electronic waste is subjected to roasting treatment. The roasting treatment conditions are: temperature 600 °C, 1 hour. The content of each metal in the metal mixture obtained after roasting is measured, and the results are shown in Table 1. The overall separation strategy is as Figure 9 shown;

[0062] Table 1

[0063] Types of metal elements Content (wt%) Au 70.11967 In 19.59215 Sn 3.22208 Mn 1.31864 Cr 1.19592 Sb 1.04901 Fe 1.02741 Na 0.63986 Zn 0.59874 Cu 0.33544 Mg 0.30904 Co 0.27047 Al 0.15311 Li 0.07108 Ni 0.05613 Ba 0.04125

[0064] The metal mixture is placed on the heating element carbon paper, and then chlorine gas is introduced. The reaction temperature is 600 °C - 800 °C and the reaction time is 5 s - 10 s; indium oxide in the metal mixture specifically reacts to form indium chloride, while other metal compounds in the metal mixture, such as MnO, SnO 2 , Au, Cr 2 O 3 remain in their original forms. Further, based on the relatively high vapor pressure of indium chloride, the separation and recovery of indium metal from other mixed systems are realized;

[0065] The recovery rate of indium metal and the purity of the recovered indium metal were tested. As Figure 10 and Figure 11 shown, when the input voltage is 105V, the purity of indium metal can reach 94%, and the recovery rate of indium metal can reach 92%;

[0066] The indium chloride recovered under the above conditions was characterized. The XRD of the recovered indium chloride is as Figure 12 shown, and its XRD pattern corresponds to the standard card, indicating the obtained indium chloride material.

[0067] Example 2

[0068] Target metal: gallium metal

[0069] The waste light-emitting diodes were calcined. The calcination conditions were: temperature 700°C, 1.5 hours; the contents of various metals in the metal mixture obtained after calcination were measured, and the results are shown in Table 2. The overall separation strategy is as Figure 13 shown;

[0070] Table 2

[0071] Types of metal elements Content (wt%) Au 25.79145 Ag 11.33929 Si 36.90113 Ga 25.96813

[0072] The metal mixture was placed on the heating carbon cloth, and then chlorine gas was introduced. At a reaction temperature of 300°C - 1500°C and a reaction time of 5s - 30s, gallium nitride can undergo a chlorination reaction to form gallium chloride at the above temperature, and silver metal is converted into silver chloride, while other metal compounds in the metal mixture, such as Au, SiO 2 , AgCl remain in their original forms. Further, based on the relatively high vapor pressure of gallium chloride, the separation and recovery of indium metal from other mixed systems can be achieved;

[0073] The recovery rate of gallium metal and the purity of the recovered gallium metal were tested, which are closely related to the temperature of the electrothermal chlorination reaction. Within the temperature range where the chlorination reaction can occur, as Figure 14 and Figure 15 shown, when the input voltage is 110V, the purity of gallium metal can reach 99%; when the input voltage is 130V, the recovery rate of gallium metal can reach 86%. Higher temperatures at higher voltages are beneficial to the full chlorination reaction of the target metal in the metal mixture, so higher recovery rates can be achieved; the chloride of the obtained gallium metal is hygroscopic and is converted into gallium oxide in the air, so the finally recovered product is gallium oxide.

[0074] The recovered gallium chloride was calcined and then characterized. The XRD of the recovered gallium oxide is as Figure 16 shown, indicating the obtained gallium oxide material.

[0075] Example 3

[0076] Target metal: tantalum metal

[0077] The tantalum capacitor waste is calcined under the following conditions: temperature 800 °C, 2 hours; the content of each metal in the metal mixture obtained after calcination is measured, as shown in Table 3, and the overall separation strategy is as Figure 17 shown;

[0078] Table 3

[0079] Types of metal elements Content (wt%) Si 40.56859 Ta 37.7904 Mn 9.98924 Cu 3.14976 Fe 1.69323 Ni 1.62914 Ag 1.01348 Pb 0.86808 Ba 0.71068 Zn 0.64405 Ti 0.43666 Na 0.41129 Au 0.39216 Cr 0.3531 Al 0.19468 Mg 0.12365

[0080] The metal mixture is placed on a heating carbon felt, and then chlorine gas is introduced. At a reaction temperature of 1200 °C - 1400 °C and a reaction time of 20 s - 40 s, the impurity metals specifically undergo chlorination reactions to form corresponding chlorides, while silicon oxide and tantalum oxide remain in their original forms. Further, based on the good solubility of the chlorides corresponding to the impurity metals, the separation of tantalum metal and silicon from other components is achieved; secondly, silicon oxide and tantalum oxide are mixed with carbon, and chlorine gas is introduced. At a reaction temperature of 900 - 1100 °C and a reaction time of 20 s - 40 s, tantalum is selectively converted to TaOCl, while silicon remains as silicon oxide. Further, based on the difference in vapor pressure between the chloride and the oxide, the separation of tantalum and silicon is achieved, thus finally realizing the recovery of tantalum metal;

[0081] Testing the recovery rate of tantalum metal and the purity of the recovered tantalum metal is closely related to the conditions of electrothermal chlorination reaction, as Figure 18 shown. Under the optimized reaction conditions, that is, the first heat treatment is at 120 V for 32 s and the second heat treatment is at 130 V for 32 s, the purity of the recovered tantalum metal can reach 96%; as Figure 19 shown. Under the optimized conditions, that is, after 130 V for 40 s, the recovery rate of tantalum metal can reach 94%;

[0082] The obtained tantalum oxychloride is calcined and then characterized. After calcination, the tantalum oxychloride is converted to tantalum oxide. The XRD of the recovered tantalum oxide is as Figure 20 shown, indicating that high-purity tantalum oxide is obtained.

[0083] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. "The first feature" and "the second feature" may include one or more of such features.

[0084] In the description of the present application, "a plurality of" means two or more.

[0085] In the description of the present application, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but are in contact through additional features therebetween.

[0086] In the description of the present application, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature.

[0087] In the description of the present application, "A and / or B" may include the case of A alone, the case of B alone, and any one of the cases of A and B. Here, A and B are only for illustration purposes, and they may be any technical features connected by "and / or" in the present application.

[0088] In the description of the present application, "the same chemical composition" should be understood in a broad sense, that is, the main components of the two have a consistent chemical composition, or the chemical compositions of the two are basically the same, and may have errors within the range understandable by those skilled in the art and permitted in the art, or contain impurities within the permitted range.

[0089] It should be noted that the writing order of each step in the present application does not mean a strict execution order and does not impose any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic. If there is no special instruction, all steps of the present application can be carried out in sequence or randomly, and preferably in sequence. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out in sequence, or may also include steps (b) and (a) carried out in sequence. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may also include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0090] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and embodiments having the same composition and achieving the same effect as the technical idea within the technical solution scope of the present application are all included in the technical scope of the present application. In addition, within the scope not departing from the gist of the present application, various modifications that those skilled in the art can think of to the embodiments, and other ways constructed by combining some constituent elements of the embodiments are also included in the scope of the present application.

Claims

1. A method for selectively recovering metals, characterized in that: include: Mixing a metal mixture with a chlorinating agent to obtain a first mixture, wherein the metal element in the metal mixture includes at least one of gallium, indium, and tantalum; Heat-treating the first mixture to obtain a second mixture, wherein the second mixture includes a chloride corresponding to the metal element, wherein the temperature of the heat treatment is 200° C.-2500° C., and the time of the heat treatment is 5 seconds-5 minutes; The second mixture is subjected to separation treatment to obtain a purified compound corresponding to the metal element.

2. The method according to claim 1, characterized in that The metal mixture includes at least one of electronic waste, ore, tailings, alloy, metal oxide, metal sulfide and metal nitride.

3. The method according to claim 1, characterized in that The chlorination reagent includes a solid chlorination reagent and / or a gaseous chlorination reagent, wherein the solid chlorination reagent includes at least one of a metal chloride salt, a non-metal chloride salt, and a chlorine-containing polymer, and the gaseous chlorination reagent includes at least one of chlorine and hydrogen chloride.

4. The method according to claim 1, characterized in that: The heating rate of the heating treatment is 1000°C / s-5000°C / s; and / or the cooling rate of the heating treatment is 100°C / s-500°C / s.

5. The method according to any one of claims 1 to 4, characterized in that: The heating process includes a pulse discharge heating process.

6. The method according to claim 5, characterized in that The heating treatment of the first mixture includes placing the first mixture on a heating element, the resistivity of the heating element is 1 mΩ·cm-10 mΩ·cm, and the voltage of the heating element is 20V-180V.

7. The method according to claim 6, characterized in that The heating element includes at least one of a metal conductor and a carbon fiber product, wherein the carbon fiber product includes at least one of carbon paper, carbon cloth, carbon felt, and graphite sheet.

8. The method according to claim 2, characterized in that: Before mixing the metal mixture with the chlorination agent, the method further comprises: The electronic waste is subjected to a calcination treatment to obtain the metal mixture, wherein the calcination treatment temperature is 500° C.-1000° C.

9. The method according to any one of claims 1 to 4, characterized in that: The separation process includes at least one of evaporation separation, dissolution-filtration separation, and magnetic separation.

10. A device for selectively recovering metals, characterized in that: The device for selectively recovering metals adopts the method described in any one of claims 1 to 9 to recover metals.

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