A method for leaching valuable metals from black powder recovered from ternary batteries

Abstract

The present invention discloses a method for leaching valuable metals from black powder recovered from ternary batteries. The method comprises the following steps: (1) dynamic reduction roasting pretreatment: the black powder recovered from waste nickel-cobalt-manganese ternary lithium batteries is placed in a protective atmosphere dynamic roasting furnace; (2) two-stage countercurrent water leaching for lithium extraction: the reduction roasted material is mixed with pure water at a liquid-solid mass ratio of 6-8:1, and then a mixed slurry reaction is carried out at a temperature of 40-60°C and a reaction time of 30-45 minutes; (3) atmospheric pressure leaching plus high-pressure acid leaching combined with two-stage countercurrent leaching. The present invention improves the leaching rate of valuable metals such as nickel, cobalt and manganese, with the leaching rate of nickel, cobalt and manganese all exceeding 99.5%. The addition of a reducing agent during the leaching process is avoided, which greatly reduces the reagent cost, optimizes the process, and improves the reaction rate.

Description

Technical Field

[0001] The present invention relates to the technical field of waste battery material recycling, and in particular to a method for leaching valuable metals from black powder recovered from ternary batteries. Background Art

[0002] With the rapid replacement of electronic products and the rapid development of electric vehicles, an increasing number of used nickel-cobalt-manganese lithium-ion batteries are being generated. These batteries contain a large amount of toxic and hazardous substances, which pose a serious threat to the environment and human health. Furthermore, used lithium-ion batteries are rich in valuable metals and can serve as an important secondary resource. To achieve the recycling of valuable metal resources and reduce the environmental impact of solid waste disposal, the recycling of used lithium-ion batteries has received widespread attention. After discharging, disassembling, crushing, sorting, and separating used batteries, the resulting black mixture, generally referred to as black powder, contains large amounts of valuable metals such as lithium, nickel, cobalt, and manganese.

[0003] For the recycling of valuable metals in black powder, the hydrometallurgical process is considered to be a low-energy, low-cost, low-pollution waste lithium-ion battery recycling technology that is more suitable for large-scale application. The hydrometallurgical recovery process includes battery pretreatment, valuable metal leaching, and high-value-added product recovery. Among them, the leaching process is the key step in the entire hydrometallurgical recovery of valuable metal elements in waste lithium-ion batteries. According to relevant literature reports, the leaching of black powder can be divided into inorganic acid leaching, organic acid leaching, ammonia leaching, and biological leaching according to the different leaching agents and leaching methods. The more commonly used ones are inorganic acid leaching and organic acid leaching.

[0004] Inorganic acids such as H2SO4, HCl, HNO3, and H3PO4 are commonly used leaching agents for cathode powder leaching. Because the chemical valences of cobalt and manganese in cathode materials are +3 and +4, high-valent Co and Mn compounds cannot exist as ions in aqueous solution. Therefore, during the leaching process, reducing agents such as sodium sulfite, sodium thiosulfate, sodium metabisulfite, and hydrogen peroxide are often added to reduce Co and Mn from their high-valent oxide phases to their water-soluble, low-valent Co2+ and Mn2+ forms, thereby increasing their leaching efficiency. However, this also introduces a large number of impurity ions, increasing reagent costs and wastewater production.

[0005] Using inorganic acids as leaching agents, with the assistance of reducing agents, can achieve higher leaching rates of valuable metal elements. However, most inorganic acids are medium-strong acids with strong corrosiveness, placing high demands on leaching equipment. Furthermore, the leaching process produces harmful gases such as Cl2, SO2, and NOx, which deteriorate the operating environment, require gas collection and purification equipment, and increase environmental pressure. Compared with inorganic acids, most organic acids are weak acids, requiring less demanding leaching equipment. Furthermore, organic acids are naturally degradable and less likely to cause secondary pollution. Furthermore, most organic acids have a certain degree of reducing power. For example, oxalic acid, citric acid, and ascorbic acid exhibit strong reducing properties. As leaching agents, they can promote the reduction of high-valent metal oxidation states to low-valent states.

[0006] Both inorganic and organic acid leaching are based on the reaction between hydrogen ions and the cathode active powder in an acidic medium. The residual acid concentration in the leachate obtained after acid leaching is often high. For example, in the recovery of precursors, the pH required for complete precipitation of nickel, cobalt, and manganese hydroxides is above 10. Therefore, a large amount of alkali is required to neutralize the residual acid in the leachate, which results in additional costs.

[0007] It can be seen that in the prior art, on the one hand, due to the large amount of reducing agents used in the leaching process, a large amount of sodium ions are often introduced, and the metal recovery rate in a single leaching process is low, and the production efficiency is low. On the other hand, the obtained leachate is often highly acidic, and a large amount of neutralizer is required to neutralize the residual acid, which results in a high reagent cost. Summary of the Invention

[0008] In response to the above technical problems, the present invention provides a method for leaching valuable metals from black powder recovered from ternary batteries.

[0009] In order to achieve the above object, the technical solution of the present invention is as follows:

[0010] A method for leaching valuable metals from black powder recovered from ternary batteries, comprising the following steps:

[0011] (1) Dynamic reduction roasting pretreatment: The black powder recovered from the waste nickel-cobalt-manganese ternary lithium battery is placed in a protective atmosphere dynamic roasting furnace, after the reducing gas is introduced, the dynamic reduction roasting is carried out at a roasting temperature of 450-550°C and a roasting time of 2-3 hours to reduce the valuable metal elements therein into metal or oxide form to obtain the reduction roasted material;

[0012] (2) Two-stage countercurrent water leaching for lithium extraction: After the reduction roasted material is mixed with pure water at a liquid-solid mass ratio of 6-8:1, a mixed slurry reaction is carried out at a temperature of 40-60°C and a reaction time of 30-45 minutes, and a first-stage water leaching liquid and a first-stage water leaching residue rich in lithium are obtained after filtration, and the first-stage water leaching is completed. The first-stage water leaching liquid is post-treated to precipitate lithium, and the first-stage water leaching residue is mixed with new water at a liquid-solid mass ratio of 6-8:1. After the mixed slurry reaction is carried out at a temperature of 40-60°C and a reaction time of 30-45 minutes, a second-stage water leaching liquid and a second-stage water leaching residue are obtained after filtration, and the second-stage water leaching is completed. The second-stage water leaching liquid is post-treated to precipitate lithium, and the remaining liquid is returned for the next round of first-stage water leaching;

[0013] (3) Normal pressure leaching plus high pressure acid leaching combined with two-stage countercurrent leaching: pure water is added to the second-stage water leaching residue at a liquid-solid mass ratio of 5-10:1, stirred and heated, and when the temperature rises to 60-80°C, sulfuric acid solution is added dropwise for leaching. The leaching time is 1 hour, and the pH value at the end of the reaction process is controlled to be 2-4. After the reaction is continued, precipitation is carried out, and solid-liquid separation is carried out to complete one-stage normal pressure leaching, and normal pressure leachate and normal pressure leach residue are obtained. The normal pressure leachate is subjected to post-treatment;

[0014] According to the liquid-solid mass ratio of 5-10:1, an acid solution with a concentration of 4-6 mol / L is added to the atmospheric pressure leaching residue to carry out two-stage high-pressure acid leaching. The leaching temperature is 130-180°C, the leaching pressure is 0.4-0.8 MPa, and the leaching time is 1 hour. After continuing the reaction, precipitation is carried out, and solid-liquid separation is carried out to complete the two-stage high-pressure acid leaching to obtain high-pressure leachate and high-pressure leaching residue. The high-pressure leaching residue is post-processed to recover the carbon powder therein. The high-pressure leachate and new water are mixed in a volume ratio of 1:4-6, and then added to the two-stage water leaching residue to carry out the next round of one-stage atmospheric pressure leaching.

[0015] Wherein, in step (1), the reducing gas introduced is hydrogen or sulfur dioxide gas.

[0016] Wherein, in the step (3), during the second stage high pressure acid leaching process, the acid solution used is sulfuric acid, hydrochloric acid or nitric acid.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) In the reduction roasting pretreatment stage, dynamic calcination is used to make the material reduction more complete. At the same time, hydrogen or sulfur dioxide gas is used to pre-reduce the material, reducing the valuable metal elements into metal or oxide form, and dissociating lithium from the nesting of nickel, cobalt and manganese compounds, making the leaching process easier.

[0019] (2) The preferential lithium extraction process is adopted to recover lithium first, which improves the lithium recovery rate compared with the current mainstream post-lithium extraction process.

[0020] (3) During the leaching process, a two-stage leaching method of atmospheric pressure leaching and high-pressure leaching was used. The atmospheric pressure leaching process controlled the pH value of the output leachate, saving costs for subsequent leachate purification and separation. The high-pressure leaching stage made it easier to extract the valuable metals in the material, further improving the leaching rate of nickel, cobalt and manganese in the material and optimizing the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0023] Example 1

[0024] like Figure 1 As shown, a method for leaching valuable metals from black powder recovered from ternary batteries comprises the following steps:

[0025] (1) Dynamic reduction roasting pretreatment: The black powder recovered from the waste nickel-cobalt-manganese ternary lithium battery is placed in a protective atmosphere dynamic roasting furnace, and after the reducing gas is introduced, the dynamic reduction roasting is carried out at a roasting temperature of 450°C and a roasting time of 2 hours to reduce the valuable metal elements therein into metal or oxide form to obtain the reduction roasted material;

[0026] (2) Two-stage countercurrent water leaching for lithium extraction: After the reduction roasted material is mixed with pure water at a liquid-solid mass ratio of 6:1, a mixed slurry reaction is carried out at a temperature of 40°C and a reaction time of 30 minutes. After filtering, a lithium-rich first-stage water leaching liquid and a first-stage water leaching residue are obtained, and the first-stage water leaching is completed. The first-stage water leaching liquid is post-processed to precipitate lithium. After the first-stage water leaching residue is mixed with new water at a liquid-solid mass ratio of 6:1, a mixed slurry reaction is carried out at a temperature of 40°C and a reaction time of 30 minutes. After filtering, a second-stage water leaching liquid and a second-stage water leaching residue are obtained, and the second-stage water leaching is completed. The second-stage water leaching liquid is post-processed to precipitate lithium, and the remaining liquid is returned for the next round of first-stage water leaching;

[0027] (3) Normal pressure leaching plus high pressure acid leaching combined with two-stage countercurrent leaching: pure water is added to the second-stage water leaching residue at a liquid-solid mass ratio of 5:1, stirred and heated. When the temperature rises to 60°C, sulfuric acid solution is added dropwise for leaching. The leaching time is 1 hour. The pH value at the end of the reaction process is controlled to be 2. After continuing the reaction, precipitation is carried out, solid-liquid separation is carried out, and one-stage normal pressure leaching is completed to obtain normal pressure leachate and normal pressure leach residue. The normal pressure leachate is subjected to post-treatment;

[0028] According to the liquid-solid mass ratio of 5:1, an acid solution with a concentration of 4 mol / L was added to the atmospheric pressure leaching residue to carry out two-stage high-pressure acid leaching. The leaching temperature was 130°C, the leaching pressure was 0.4 MPa, and the leaching time was 1 hour. After continuing the reaction, precipitation was carried out, and solid-liquid separation was carried out to complete the two-stage high-pressure acid leaching to obtain high-pressure leachate and high-pressure leaching residue. The high-pressure leaching residue was post-treated to recover the carbon powder therein. The high-pressure leachate and new water were mixed in a volume ratio of 1:4 and added to the two-stage water leaching residue for the next round of one-stage atmospheric pressure leaching.

[0029] Wherein, in step (1), the reducing gas introduced is hydrogen or sulfur dioxide gas.

[0030] Wherein, in the step (3), during the second stage high pressure acid leaching process, the acid solution used is sulfuric acid, hydrochloric acid or nitric acid.

[0031] Example 2

[0032] like Figure 1 As shown, a method for leaching valuable metals from black powder recovered from ternary batteries comprises the following steps:

[0033] (1) Dynamic reduction roasting pretreatment: The black powder recovered from the waste nickel-cobalt-manganese ternary lithium battery is placed in a protective atmosphere dynamic roasting furnace, and after the reducing gas is introduced, the dynamic reduction roasting is carried out at a roasting temperature of 550°C and a roasting time of 3 hours to reduce the valuable metal elements therein into metal or oxide form to obtain the reduction roasted material;

[0034] (2) Two-stage countercurrent water leaching for lithium extraction: After the reduction roasted material is mixed with pure water at a liquid-solid mass ratio of 8:1, a mixed slurry reaction is carried out at a temperature of 60°C and a reaction time of 45 minutes, and a first-stage water leaching liquid and a first-stage water leaching residue rich in lithium are obtained after filtration, and the first-stage water leaching is completed. The first-stage water leaching liquid is post-processed to precipitate lithium. The first-stage water leaching residue is mixed with new water at a liquid-solid mass ratio of 8:1, and a mixed slurry reaction is carried out at a temperature of 60°C and a reaction time of 45 minutes. After filtration, a second-stage water leaching liquid and a second-stage water leaching residue are obtained, and the second-stage water leaching is completed. The second-stage water leaching liquid is post-processed to precipitate lithium, and the remaining liquid is returned for the next round of first-stage water leaching;

[0035] (3) Normal pressure leaching plus high pressure acid leaching combined with two-stage countercurrent leaching: pure water is added to the second-stage water leaching residue at a liquid-solid mass ratio of 10:1, stirred and heated, and when the temperature rises to 80°C, sulfuric acid solution is added dropwise for leaching. The leaching time is 1 hour, and the pH value at the end of the reaction process is controlled to be 4. After the reaction is continued, precipitation is carried out, and solid-liquid separation is performed to complete one-stage normal pressure leaching, and normal pressure leachate and normal pressure leach residue are obtained. The normal pressure leachate is subjected to post-treatment;

[0036] According to the liquid-solid mass ratio of 10:1, an acid solution with a concentration of 6 mol / L was added to the atmospheric pressure leaching residue to carry out two-stage high-pressure acid leaching. The leaching temperature was 180°C, the leaching pressure was 0.8 MPa, and the leaching time was 1 hour. After the reaction was continued, the mixture was precipitated and solid-liquid separation was carried out to complete the two-stage high-pressure acid leaching to obtain high-pressure leachate and high-pressure leaching residue. The high-pressure leaching residue was post-treated to recover the carbon powder therein. The high-pressure leachate and new water were mixed in a volume ratio of 1:6 and added to the two-stage water leaching residue to carry out the next round of one-stage atmospheric pressure leaching.

[0037] Wherein, in step (1), the reducing gas introduced is hydrogen or sulfur dioxide gas.

[0038] Wherein, in the step (3), during the second stage high pressure acid leaching process, the acid solution used is sulfuric acid, hydrochloric acid or nitric acid.

[0039] Example 3

[0040] like Figure 1 As shown, a method for leaching valuable metals from black powder recovered from ternary batteries comprises the following steps:

[0041] (1) Dynamic reduction roasting pretreatment: Weigh 1000g of battery black powder, whose main components are Co 8.16%, Ni 25.32%, Mn 18.74%, Li 4.84%, Fe 0.75%, C 23.44%, Al 1.47%, Cu 0.12%, and Ca 0.18%. Load it into the test type dynamic rotary protective atmosphere roasting furnace material boat, connect nitrogen and hydrogen gas sources, and check the air tightness and equipment status to ensure there are no leaks. Set the rotation speed to 5rpm, start the power supply, set the heating program, set the heating time to 1 hour, the heating rate to 7℃ / min, and the temperature to 450℃. When the temperature reaches 450℃, keep warm for 2 hours. After the heat preservation ends, start cooling, and the cooling time is 2 hours. After the setting program is completed, start the heating power supply and start heating. At the same time, introduce nitrogen to purge and replace the air in the furnace. When the temperature reached 450°C, the nitrogen atmosphere was switched to hydrogen, and hydrogen was introduced for reduction roasting for 2 hours. After roasting, the hydrogen atmosphere was switched to nitrogen, the purge was continued, and cooling water was introduced to begin cooling. When the temperature dropped to room temperature, the nitrogen atmosphere was turned off, the roasting furnace was opened, and the roasted material was removed and weighed to 826.4g. This was retained and sampled for analysis, revealing its main components: Ni (9.98%), Co (0.02%), Mn (9.28%), and Li (5.77%). The phase composition was Ni, Co, MnO, C, and Li2O, indicating that the reduction process reduced the main metal elements to metallic or oxidized states.

[0042] (2) Two-stage water leaching for lithium extraction: 400 g of the material after dynamic reduction roasting was weighed and placed in a 5-liter beaker. 3200 mL of pure water was added for slurrying. The material was placed in a constant temperature water bath with a set temperature of 60°C. After slurrying and stirring for 40 minutes, solid-liquid separation was performed to obtain 3107 mL of first-stage water leaching liquid and 378 g of first-stage water leaching residue (after drying). Sampling and analysis showed that the first-stage water leaching liquid contained 6.54 g / L of Li and the first-stage water leaching residue contained 0.73% of lithium. The first-stage water leaching residue was further slurried with 3200 mL of pure water and soaked in water at 60°C for 40 minutes. Solid-liquid separation was performed to obtain 3180 mL of second-stage water leaching liquid and 364 g of second-stage water leaching residue (after drying). Sampling and analysis showed that the second-stage water leaching liquid contained 0.74 g / L of Li and the first-stage water leaching residue contained 0.097% of Li. After two-stage leaching, the total leaching rate of lithium slag was 98.47%.

[0043] 400g of the dynamic reduction roasted material was weighed again and slurried with 3180mL of the first two-stage water leaching solution. Countercurrent water leaching was performed, yielding 3096mL of first-stage water leaching solution containing 7.28g / L of Li and 381g of first-stage water leaching residue (after drying) with a Li content of 0.85%. 3200mL of fresh pure water was added to the first-stage water leaching residue for a second stage of water leaching, yielding 3174mL of second-stage water leaching solution containing 0.87g / L of Li and 368g of first-stage water leaching residue (after drying) with a Li content of 0.11g / L. The total leaching rate based on the slag was 98.18%. After two countercurrent water leachings for lithium extraction, 800g of the roasted material was added, yielding a total of 732g of water-leached residue, which was retained.

[0044] (3) Atmospheric pressure leaching plus high-pressure acid leaching combined with two-stage leaching: Weigh 300g of the slag after water leaching and place it in a 5L beaker, add 1800mL of pure water, place it in a water bath, and install a mechanical stirrer. Set the stirring speed to 300rpm, start stirring, and heat up. When the temperature rises to 80℃, start adding sulfuric acid solution dropwise, and control the pH value of the reaction process to 2.5 at the end. When the pH value no longer changes, stop adding sulfuric acid solution, continue the reaction and precipitation for 1 hour, and then perform solid-liquid separation to obtain 1763mL of atmospheric pressure leaching solution. The atmospheric pressure leaching slag is weighed after drying and is 71.3g. According to calculations, the nickel leaching rate in the atmospheric pressure leaching process is 82.11%, the cobalt leaching rate is 87.36%, and the manganese leaching rate is 96.33%.

[0045] 71.3 g of atmospheric leaching residue was placed in the interior of an experimental 2 L autoclave, and 700 mL of 4.5 mol / L sulfuric acid solution was prepared and slowly added to the interior of the autoclave. After the autoclave was installed, the seal, pressure gauge, vent valve, exhaust and recovery device, and circulating cooling water pipeline were checked. After confirming that they were normal, the heating program was set, the temperature was set to 140 ° C, the stirring speed was set to 300 rpm, the power was turned on, the stirring was turned on, and the temperature began to rise. When the temperature reached 140 ° C, the reaction was kept warm for 1 hour. At this time, the pressure in the autoclave was 0.55 MPa. After the reaction was completed, the heating system was turned off and the circulating cooling water was started to start cooling. When the temperature drops to room temperature, turn off the system power, open the vent valve, and release the pressure. Then, remove the autoclave and pour out the reacted slurry. Perform solid-liquid separation to obtain 673 mL of leaching solution. The leached residue weighs 11.45 g after drying. The leached residue sample is analyzed and the Ni content is 0.05%, Co is 0.03%, Mn is 0.03%, and C is 93.22%, indicating that after high-pressure leaching, the valuable metal content is extremely low, and it is mainly carbon powder.

[0046] After normal pressure and high pressure leaching, the total leaching rate of nickel was 99.83%, the total leaching rate of cobalt was 99.78%, and the total leaching rate of manganese was 99.87%.

[0047] The present invention adopts a process of dynamic reduction roasting pretreatment, two-stage countercurrent water leaching to extract lithium, and atmospheric pressure leaching plus high-pressure acid leaching combined with two-stage countercurrent leaching to extract nickel, cobalt and manganese. Compared with the existing process technology, the present invention realizes the priority extraction of lithium from the ternary black powder material, and pre-separates lithium from nickel, cobalt and manganese. The lithium water leaching rate is greater than 95%. At the same time, a leaching method of atmospheric pressure pre-leaching plus high-pressure leaching two-stage countercurrent is adopted to improve the leaching rate of valuable metals such as nickel, cobalt and manganese. The leaching rate of nickel, cobalt and manganese is greater than 99.5%, which saves the addition of reducing agent in the leaching process, greatly reduces the reagent cost, optimizes the process, and improves the reaction rate.

[0048] Among them, in Examples 1-3, the black powder recovered from waste nickel-cobalt-manganese ternary lithium batteries contains: 4-6% lithium, 15-30% nickel, 5-20% cobalt, 10-20% manganese, and 18-25% carbon.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for leaching valuable metals from black powder recovered from ternary batteries, characterized in that: The following steps are involved: (1) Dynamic reduction roasting pretreatment: The black powder recovered from the waste nickel-cobalt-manganese ternary lithium battery is placed in a protective atmosphere dynamic roasting furnace, after the reducing gas is introduced, the dynamic reduction roasting is carried out at a roasting temperature of 450-550°C and a roasting time of 2-3 hours to reduce the valuable metal elements therein into metal or oxide form to obtain the reduction roasted material; (2) Two-stage countercurrent water leaching for lithium extraction: After the reduction roasted material is mixed with pure water at a liquid-solid mass ratio of 6-8:1, a mixed slurry reaction is carried out at a temperature of 40-60°C and a reaction time of 30-45 minutes, and a first-stage water leaching liquid and a first-stage water leaching residue rich in lithium are obtained after filtration, and the first-stage water leaching is completed. The first-stage water leaching liquid is post-treated to precipitate lithium, and the first-stage water leaching residue is mixed with new water at a liquid-solid mass ratio of 6-8:

1. After the mixed slurry reaction is carried out at a temperature of 40-60°C and a reaction time of 30-45 minutes, a second-stage water leaching liquid and a second-stage water leaching residue are obtained after filtration, and the second-stage water leaching is completed. The second-stage water leaching liquid is post-treated to precipitate lithium, and the remaining liquid is returned for the next round of first-stage water leaching; (3) Normal pressure leaching plus high pressure acid leaching combined with two-stage countercurrent leaching: pure water is added to the second-stage water leaching residue at a liquid-solid mass ratio of 5-10:1, stirred and heated, and when the temperature rises to 60-80°C, sulfuric acid solution is added dropwise for leaching. The leaching time is 1 hour, and the pH value at the end of the reaction process is controlled to be 2-4. After the reaction is continued, precipitation is carried out, and solid-liquid separation is carried out to complete one-stage normal pressure leaching, and normal pressure leachate and normal pressure leach residue are obtained. The normal pressure leachate is subjected to post-treatment; According to the liquid-solid mass ratio of 5-10:1, an acid solution with a concentration of 4-6 mol / L is added to the atmospheric pressure leaching residue to carry out two-stage high-pressure acid leaching. The leaching temperature is 130-180°C, the leaching pressure is 0.4-0.8 MPa, and the leaching time is 1 hour. After continuing the reaction, precipitation is carried out, and solid-liquid separation is carried out to complete the two-stage high-pressure acid leaching to obtain high-pressure leachate and high-pressure leaching residue. The high-pressure leaching residue is post-processed to recover the carbon powder therein. The high-pressure leachate and new water are mixed in a volume ratio of 1:4-6, and then added to the two-stage water leaching residue to carry out the next round of one-stage atmospheric pressure leaching.

2. The method for leaching valuable metals from black powder recovered from ternary batteries according to claim 1, characterized in that: In the step (1), the reducing gas introduced is hydrogen or sulfur dioxide gas.

3. The method for leaching valuable metals from black powder recovered from ternary batteries according to claim 1, characterized in that: In the step (3), during the second-stage high-pressure acid leaching process, the acid solution used is sulfuric acid, hydrochloric acid or nitric acid.

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