Recovery method of nickel cobalt lithium manganate

Abstract

The invention provides a recovery method of nickel cobalt lithium manganate. The nickel cobalt lithium manganate recovery process has the remarkable advantages that the resource recovery efficiency is high, accurate recovery of all components of nickel, cobalt, manganese and lithium and recovery of graphite powder are achieved through roasting pretreatment and step-by-step separation, and various high-quality products are obtained; impurities are thoroughly removed through a multi-stage purification process, and the product purity is guaranteed. A multi-circulation reuse mechanism reduces water and agent consumption, natural gas countercurrent roasting reduces energy consumption, energy conservation and environmental protection are achieved, and the cost is controllable; the carbon powder is flexible in proportion, adjustable in process parameters, suitable for various raw materials, high in stability and in line with the green recovery trend.

Description

Technical Field

[0001] This invention belongs to the field of new energy material recycling and resource utilization technology, specifically relating to a method for recycling lithium nickel cobalt manganese oxide. Background Technology

[0002] With the global energy structure transformation and the rapid development of the new energy vehicle industry, ternary lithium batteries (lithium nickel cobalt manganese oxide system) have been widely used in power batteries, energy storage equipment, and other fields due to their high energy density and excellent cycle performance. However, as the first batch of ternary lithium batteries gradually enters their scrap cycle, the recycling and disposal of a large amount of lithium nickel cobalt manganese oxide waste (including battery powder and electrode powder from dismantled ternary batteries) has become an urgent industry problem to be solved. These wastes not only contain a variety of high-value metals such as nickel, cobalt, manganese, and lithium, but also recyclable components such as graphite, copper, and aluminum. If they are discarded or improperly disposed of, it will not only cause serious waste of resources, but may also cause ecological and environmental risks to soil and water bodies due to heavy metal leakage and electrolyte pollution. Therefore, achieving efficient resource recycling of lithium nickel cobalt manganese oxide waste has important economic value and environmental significance.

[0003] Currently, the main recycling technologies for lithium nickel cobalt manganese oxide waste developed in the industry include pyrometallurgy, hydrometallurgy, and combined pyrometallurgical and hydrometallurgical processes. Pyrometallurgical processes achieve metal oxidation-reduction and separation through high-temperature roasting, but suffer from drawbacks such as high energy consumption, large equipment investment, and potential secondary pollution, and struggle to achieve efficient recovery of elements like lithium and manganese. Traditional hydrometallurgical processes often employ a combination of steps including direct acid leaching, chemical precipitation, and solvent extraction. While they can recover some metals, they suffer from low leaching efficiency, high reagent consumption, and incomplete impurity separation. This is particularly problematic for components mixed in the waste, such as negative electrode graphite and metallic impurities, making efficient separation and resource utilization difficult, resulting in insufficient product purity and high recycling costs. Furthermore, existing processes generally suffer from uneven resource recovery rates. Some processes focus on nickel and cobalt recovery while neglecting the recovery value of lithium, manganese, and graphite, failing to achieve synergistic recovery of all components in the waste, and resource utilization needs further improvement.

[0004] In practical industrial applications, the composition of lithium nickel cobalt manganese oxide (LCO) waste is complex and highly variable. The proportions of nickel, cobalt, manganese, and lithium vary significantly from different sources, and it often contains graphite and binder residues from the anode material, as well as impurities such as copper and aluminum. Traditional processes have poor adaptability to raw materials. When the carbon and impurity content in the waste fluctuates, problems such as incomplete roasting, unstable leaching systems, and decreased extraction and separation efficiency can easily occur, leading to a lower product qualification rate. Furthermore, existing processes do not efficiently recycle washing water and leachate, increasing water consumption and potentially causing environmental pressure due to wastewater discharge. Therefore, developing a highly adaptable, resource-efficient, energy-saving, and environmentally friendly LCO waste recycling technology that enables the synergistic recovery of all components has become an urgent need for the industry. Summary of the Invention

[0005] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. To this end, the present invention provides a method for recovering lithium nickel cobalt manganese oxide (LCO). This LCO recovery process achieves complete component recovery, thorough impurity removal, energy conservation through recycling, wide applicability, high stability, and aligns with green trends.

[0006] A first aspect of the present invention provides a method for recovering lithium nickel cobalt manganese oxide, comprising the following steps: S1: Mix the raw materials and toner powder evenly at a mass ratio of 1:(0.1-0.2) to obtain a mixture; S2: The mixture is roasted, with natural gas being introduced in a counter-current flow during the roasting process; S3: The material roasted in step S2 is ball-milled into a slurry; S4: After adjusting the pH of the slurry, the slurry is filtered and separated to obtain a solid product and a liquid product. The solid product is a nickel-cobalt filter cake, and the liquid product is a first mixed solution of lithium sulfate and manganese sulfate. The nickel-cobalt filter cake is washed. S5: Add calcium carbonate to the first mixed solution of lithium sulfate and manganese sulfate to react and remove aluminum, silicon and iron from the raw materials. Then filter to obtain a second mixed solution of lithium sulfate and manganese sulfate and aluminum-silicon-iron slag. S6: Add sulfide to the second mixed solution of lithium sulfate and manganese sulfate to react and remove nickel and cobalt. After the reaction, filter to obtain nickel and cobalt slag and a third mixed solution of lithium sulfate and manganese sulfate. S7: Extract the third mixed solution of lithium sulfate and manganese sulfate with P204 or P50 extractant to remove calcium and aluminum from the solution, and obtain a fourth mixed solution of lithium sulfate and manganese sulfate. S8: The fourth mixed solution of lithium sulfate and manganese sulfate is concentrated, then discharged under pressure and heat, centrifuged to obtain wet manganese sulfate crystals, dried to obtain manganese sulfate product, sodium hydroxide is added to the centrifuged liquid and air is introduced to precipitate, manganese tetroxide is obtained, and after filtration and washing, wet manganese tetroxide and lithium sulfate solution are obtained. S9: Add the nickel-cobalt sulfate high-acid mixture from step S10 to the nickel-cobalt filter cake from step S4 for leaching, and filter to obtain nickel-cobalt sulfate mixture and leaching residue; S10: Add high-concentration sulfuric acid to the leaching residue obtained in step S9, heat and leach, filter and wash to obtain a nickel-cobalt sulfate mixture and wet graphite powder, dry the wet graphite powder to obtain the graphite powder product, return the nickel-cobalt sulfate mixture to step S9, and reuse the washing water in this step. S11: Extract the nickel-cobalt sulfate mixture obtained in step S9 using P204 or P507 extractant to obtain a nickel-cobalt sulfate mixture. S12: Use P507 or C272 to separate and extract cobalt to obtain a cobalt sulfate solution, then evaporate and crystallize to obtain the cobalt sulfate product; S13: Extract nickel with P507 to obtain nickel sulfate solution, then evaporate and crystallize to obtain nickel sulfate product.

[0007] The method for recovering lithium nickel cobalt manganese oxide of the present invention has at least the following beneficial effects: The process boasts high resource recovery efficiency, achieving full-component resource utilization. The combined design of carbon powder mixing and natural gas countercurrent roasting (S1, S2) lays the foundation for efficient leaching of valuable metals. Stepwise separation (S4-S8, S9-S13) enables precise recovery of four core metals: nickel, cobalt, manganese, and lithium, yielding high-quality products such as nickel sulfate, cobalt sulfate, manganese sulfate, manganese tetroxide, and lithium sulfate (which can be used to produce lithium carbonate). Simultaneously, targeted treatment in S10-S11 recovers graphite powder, achieving full-process recovery of high-value metals and non-metallic components from waste, avoiding resource waste and enhancing the economic value of recycling.

[0008] Thorough impurity removal ensures high product purity. A multi-stage purification process precisely controls impurity interference. S5 removes aluminum, silicon, and iron by adjusting the pH with calcium carbonate; S6 deeply removes residual nickel and cobalt using sulfides; S7 and S11 use specialized extractants such as P204 or P507 to specifically remove trace impurities such as calcium, aluminum, copper, and iron. This multi-stage purification ensures the purity of subsequent metal separation. Simultaneously, S12-S13 use P507 or C272 for specialized nickel and cobalt separation, achieving efficient separation of the two metals and ensuring that the purity of nickel sulfate and cobalt sulfate products meets industrial application requirements.

[0009] The process is highly recyclable, energy-saving, environmentally friendly, and cost-controllable. A multi-stage recycling mechanism is designed to reduce consumption and emissions. S4 washing water is reused in this step, and S10 washing water is reused in situ, reducing water consumption. The high-acid nickel-cobalt sulfate mixture generated in S10 is recycled to S9, enabling the secondary utilization of sulfuric acid and residual nickel-cobalt in the leaching system. This improves the overall nickel-cobalt recovery rate and reduces the amount of fresh sulfuric acid needed, lowering reagent costs. The roasting process uses countercurrent natural gas supply, combined with carbon powder to assist the reaction, improving roasting efficiency while reducing energy consumption, aligning with the industry trend of green recycling.

[0010] It has wide raw material compatibility and high process stability. The carbon powder addition ratio in S1 (raw material to carbon powder mass ratio 1:(0.1-0.2)) can be flexibly adapted to raw materials with different carbon contents (such as ternary battery powder, ternary electrode powder, or a mixture of the two), without the need for additional adjustment of core process parameters; the reaction conditions of each step (such as pH, temperature, time) can be set within a reasonable range, and can be fine-tuned according to the fluctuation of metal content in the raw materials, avoiding process fluctuations caused by differences in raw material composition, and ensuring the stability of product quality and recovery efficiency during continuous production.

[0011] According to some embodiments of the present invention, the raw material is power battery powder or ternary electrode powder, which is black powder obtained after recycling ternary batteries or scrapped electrode sheets, and its composition is known in the art.

[0012] According to some embodiments of the present invention, in step S2, the calcination temperature is 450-850°C.

[0013] According to some embodiments of the present invention, in step S2, the roasting temperature is any value among 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, and 850°C, such as 600°C, or any range formed by both, such as 650°C to 700°C.

[0014] According to some embodiments of the present invention, in step S2, the roasting time is 30-300 min.

[0015] According to some embodiments of the present invention, in step S2, the roasting time is any value among 30min, 60min, 90min, 120min, 150min, 180min, 210min, 240min, 270min, and 300min, such as 120min, or any range formed by both, such as 90min to 180min.

[0016] According to some embodiments of the present invention, in step S2, the roasting atmosphere is natural gas.

[0017] According to some embodiments of the present invention, in step S2, the amount of natural gas used is 4-20% of the manganese mass in the raw material.

[0018] According to some embodiments of the present invention, in step S2, the amount of natural gas used is any one of 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, and 20% of the manganese mass in the raw material, such as 10%, or any range formed by both, such as 8% to 14%.

[0019] According to some embodiments of the present invention, in step S3, the particle size of the ball milling pulp is -120 to -300 mesh.

[0020] According to some embodiments of the present invention, in step S3, after the ball milling and slurry preparation is completed, the solid-liquid ratio of the slurry is 1:(2~10).

[0021] According to some embodiments of the present invention, in step S3, after the ball milling and pulping are completed, the solid-liquid ratio of the slurry is any value of 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, such as 1:5, or any range of two, such as 1:3 to 1:7.

[0022] According to some embodiments of the present invention, in step S4, the pH of the slurry is adjusted to 2.0-5.0 by adding sulfuric acid, the nickel-cobalt filter cake is washed, and the wash water is returned to this step.

[0023] According to some embodiments of the present invention, in step S5, after adding calcium carbonate, the pH is controlled to be 4.5-6.5.

[0024] According to some embodiments of the present invention, in step S4, the pH of the slurry is adjusted to any one of 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 by adding sulfuric acid, such as 3.0, or any range formed by both, such as 2.5 to 4.5, and the nickel-cobalt filter cake is washed, and the wash water is returned to this step.

[0025] According to some embodiments of the present invention, in step S5, the reaction temperature is 60-80°C.

[0026] According to some embodiments of the present invention, in step S5, the reaction temperature is any value among 60°C, 62°C, 65°C, 68°C, 70°C, 72°C, 75°C, 78°C, and 80°C, such as 70°C, or any range formed by both, such as 65°C to 75°C.

[0027] According to some embodiments of the present invention, in step S5, the reaction time is 60-300 min.

[0028] According to some embodiments of the present invention, in step S5, the reaction time is any value among 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, 270 min, and 300 min, such as 180 min, or any range formed by both, such as 120 min to 240 min.

[0029] According to some embodiments of the present invention, in step S6, the sulfide includes manganese sulfide or sodium sulfide.

[0030] According to some embodiments of the present invention, in step S6, the excess coefficient of the sulfide is 100%-200%.

[0031] According to some embodiments of the present invention, in step S6, the excess coefficient of the sulfide is any value among 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, and 200%, such as 150%, or a range of any two, such as 120% to 180%.

[0032] According to some embodiments of the present invention, in step S6, the temperature of the reaction is 60-95°C.

[0033] According to some embodiments of the present invention, in step S6, the temperature of the reaction is any value among 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, and 95°C, such as 80°C, or any range formed by both, such as 70°C to 90°C.

[0034] According to some embodiments of the present invention, in step S6, the reaction time is 60-300 min.

[0035] According to some embodiments of the present invention, in step S6, the reaction time is any value among 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, 270 min, and 300 min, such as 150 min, or any range formed by both, such as 90 min to 240 min.

[0036] According to some embodiments of the present invention, in step S6, the pH of the reaction is 5.0-6.0.

[0037] According to some embodiments of the present invention, in step S8, the fourth mixed solution of lithium sulfate and manganese sulfate is concentrated to a concentration of 80-120 g / L.

[0038] According to some embodiments of the present invention, in step S8, the fourth mixed solution of lithium sulfate and manganese sulfate is concentrated to a manganese concentration of any value among 80 g / L, 85 g / L, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L, 115 g / L, and 120 g / L, such as 100 g / L, or any range formed by both, such as 90 g / L to 110 g / L.

[0039] According to some embodiments of the present invention, in step S8, the pressure for pressurization and heat preservation is 2-3 MPa.

[0040] According to some embodiments of the present invention, in step S8, the pressure for pressurization and heat preservation is any value among 2.0MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa, 2.6MPa, 2.7MPa, 2.8MPa, 2.9MPa, and 3.0MPa, such as 2.5MPa, or any range formed by both, such as 2.2MPa to 2.8MPa.

[0041] According to some embodiments of the present invention, in step S8, the temperature of pressurization and heat preservation is 200-220°C.

[0042] According to some embodiments of the present invention, in step S8, the temperature for pressurization and heat preservation is any value among 200℃, 203℃, 205℃, 208℃, 210℃, 212℃, 215℃, 218℃, and 220℃, such as 210℃, or any range formed by both, such as 205℃~215℃.

[0043] According to some embodiments of the present invention, in step S8, the pressurization and heat preservation time is 30-60 minutes.

[0044] According to some embodiments of the present invention, in step S8, the pressurization and heat preservation time is any value among 30min, 35min, 40min, 45min, 50min, 55min, and 60min, such as 45min, or any range formed by both, such as 35min to 55min.

[0045] According to some embodiments of the present invention, in step S8, sodium hydroxide is added to the centrifuged liquid for precipitation, and the pH endpoint is controlled at 11-12.

[0046] According to some embodiments of the present invention, in step S8, the reaction temperature for adding sodium hydroxide to precipitate is 60-90°C.

[0047] According to some embodiments of the present invention, in step S8, the reaction temperature for adding sodium hydroxide to precipitate is any value among 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, and 90°C, such as 75°C, or any range formed by both, such as 65°C to 85°C.

[0048] According to some embodiments of the present invention, in step S8, the amount of air introduced is 200-1000% of the theoretical amount of manganese hydroxide converted to manganese tetroxide.

[0049] According to some embodiments of the present invention, in step S8, the amount of air introduced is any value among 200%, 300%, 400%, 500%, 600%, 700%, 800%, 900%, and 1000% of the theoretical amount of manganese hydroxide converted to manganese tetroxide, such as 600%, or any range of two, such as 400% to 800%.

[0050] According to some embodiments of the present invention, in step S9, the temperature of the leaching reaction is 60-100°C.

[0051] According to some embodiments of the present invention, in step S9, the temperature of the leaching reaction is any value among 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, and 100°C, such as 80°C, or any range formed by both, such as 70°C to 90°C.

[0052] According to some embodiments of the present invention, in step S9, the leaching reaction time is 60-600 min.

[0053] According to some embodiments of the present invention, in step S9, the leaching reaction time is any value among 60 min, 120 min, 180 min, 240 min, 300 min, 360 min, 420 min, 480 min, 540 min, and 600 min, such as 300 min, or any range formed by both, such as 180 min to 480 min.

[0054] According to some embodiments of the present invention, in step S9, the endpoint pH of the leaching reaction is 1.0-3.0.

[0055] According to some embodiments of the present invention, in step S9, the endpoint pH of the leaching reaction is any value among 1.0, 1.3, 1.5, 1.8, 2.0, 2.3, 2.5, 2.8, and 3.0, such as 2.0, or a range of any two, such as 1.5 to 2.5.

[0056] The nickel-cobalt sulfate high-acid mixture in step S10 is not supplied to step S9 only after it is newly generated. Instead, it is produced through process recycling, with reflux solution first, and then the leaching in this step is completed. The specific logic is as follows: (1) The source of the nickel-cobalt sulfate high-acid mixture in step S10 is its own leaching product + recycling. The core function of step S10 is to treat the leaching residue of step S9 (the residue contains residual nickel and cobalt elements that have not been completely leached, as well as impurities such as graphite). One of its products is the nickel-cobalt sulfate high-acid mixture. The specific generation process is as follows: In step S10, high-concentration sulfuric acid is added to the leaching residue of step S9 and leached at 60-100℃. The residual nickel and cobalt in the residue will react with sulfuric acid to generate soluble nickel sulfate and cobalt sulfate, and finally form the nickel-cobalt sulfate high-acid mixture (the solution has high acidity due to excess sulfuric acid). After filtration and washing, the mixture is directly returned to step S9 as a leaching agent, rather than being discharged from the system or used in other steps.

[0057] (2) The logic of the process cycle is: step S10 runs first, and then supplies to step S9 (or it can be a synchronous cycle). From the perspective of industrial production flow, this is a countercurrent cycle design, so there is no problem that step S10 cannot be supplied to the next step. The actual operating logic is: Initial start-up phase: During the first run, step S9 can be initially leached with a small amount of fresh high-acid nickel-cobalt sulfate solution (or high-concentration sulfuric acid), and the resulting leaching residue enters step S10; the nickel-cobalt sulfate high-acid mixed solution generated after leaching in step S10 is used as the leaching agent for subsequent batches of step S9 to achieve cyclic start-up; Stable operation phase: After the process enters continuous operation, steps S9 and S10 are carried out simultaneously. The leaching residue generated in step S9 continuously enters step S10, and the mixed liquor generated in step S10 continuously flows back to step S9, forming a closed loop of leaching residue, leaching in step S10, reflux of mixed liquor, and leaching in step S9.

[0058] (3) The purpose of the design is to improve the nickel-cobalt recovery rate and reduce reagent consumption. The mixed solution from step S10 is recycled to step S9, which has two key functions: firstly, to recover the residual nickel-cobalt in the leaching residue, thus avoiding the loss of valuable metals caused by incomplete leaching in step S9 and significantly improving the total nickel-cobalt recovery rate; secondly, to reuse the high-acid system, since the mixed solution from step S10 contains excess sulfuric acid, which can replace part of the fresh sulfuric acid after recycling, reducing the amount of sulfuric acid added in step S9 and reducing reagent consumption and production costs.

[0059] Therefore, the nickel-cobalt sulfate high-acid mixture in step S10 is a product of its own treatment of the leaching residue in step S9. It is supplied to step S9 through recycling, which is a closed-loop utilization design in industrial recycling process, rather than a linear process of completing step S9 first and then doing step S10. Therefore, there is no contradiction in the supply logic.

[0060] According to some embodiments of the present invention, in step S10, the concentration of the high-concentration sulfuric acid is 100-300 g / L.

[0061] According to some embodiments of the present invention, in step S10, the concentration of the high-concentration sulfuric acid is any value among 100g / L, 120g / L, 150g / L, 180g / L, 200g / L, 220g / L, 250g / L, 280g / L, and 300g / L, such as 200g / L, or any range formed by both, such as 150g / L to 250g / L.

[0062] Maintain this concentration during the reaction.

[0063] According to some embodiments of the present invention, in step S10, the solid-liquid ratio of the added high-concentration sulfuric acid is 1:(1.5-3.0).

[0064] According to some embodiments of the present invention, in step S10, the solid-liquid ratio of the added high-concentration sulfuric acid is any one of 1:1.5, 1:1.8, 1:2.0, 1:2.2, 1:2.5, 1:2.8, 1:3.0, such as 1:2.0, or any range of two, such as 1:1.8 to 1:2.8.

[0065] According to some embodiments of the present invention, in step S10, the temperature of the heated leaching is 60-100°C.

[0066] According to some embodiments of the present invention, in step S10, the temperature of the heating leaching is any value among 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, and 100°C, such as 80°C, or any range formed by both, such as 70°C to 90°C.

[0067] According to some embodiments of the present invention, in step S10, the heating leaching time is 60-600 minutes.

[0068] According to some embodiments of the present invention, in step S10, the heating leaching time is any value among 60min, 120min, 180min, 240min, 300min, 360min, 420min, 480min, 540min, and 600min, such as 300min, or any range formed by both, such as 180min to 480min.

[0069] According to some embodiments of the present invention, in step S10, the washing temperature for filtration washing is 60-80°C.

[0070] According to some embodiments of the present invention, in step S10, the washing temperature for filtration washing is any value among 60°C, 65°C, 70°C, 75°C, and 80°C, such as 70°C, or any range formed by both, such as 65°C to 75°C.

[0071] According to some embodiments of the present invention, in step S10, the mass ratio of washing water to solids is (1.5~3.0):1.

[0072] According to some embodiments of the present invention, in step S10, the mass ratio of washing water to solids is any one of 1.5:1, 1.8:1, 2.0:1, 2.2:1, 2.5:1, 2.8:1, and 3.0:1, such as 2.0:1, or any range formed by both, such as 1.8:1 to 2.8:1.

[0073] According to some embodiments of the present invention, in step S11, the drying temperature is 200-600℃, the drying time is 2-4h, and the fixed carbon content of the product is greater than 97%. Detailed Implementation

[0074] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0075] In the description of this invention, the references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Unless otherwise specified, room temperature in this invention refers to 25℃±5℃.

[0077] Unless otherwise specified, the allowable error in this invention is approximately within ±2%.

[0078] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0079] In the example: The crystallization rate is determined by measuring the total mass of manganese in the solution before crystallization and the mass of manganese in the precipitated manganese sulfate after crystallization, and calculating the ratio between the two. The specific test method is as follows: Sampling and volume adjustment: After concentration in step S8 and before pressure and heat preservation for crystallization, accurately take a certain volume (e.g., V1=10mL) of the fourth mixed solution of lithium sulfate and manganese sulfate, and dilute it with deionized water to a fixed volume (e.g., Vtotal=100mL) to obtain the mother liquor to be tested; Manganese content detection: The manganese concentration (C1, unit g / L) in the mother liquor was determined by atomic absorption spectrophotometry (AAS), and the total mass of manganese in the solution before crystallization was calculated. Total manganese mass m_total = C1 × V_total × (V_mother liquor / V1) (Note: V is the total volume of the concentrated mixed solution in step S8, which needs to be measured in advance.) Calculation of the mass of manganese precipitated as manganese sulfate: After centrifugation, all wet manganese sulfate crystals were collected and dried at 105℃±5℃ to constant weight. The mass of the dried manganese sulfate product was then measured (m product, in g). Calculate the mass of manganese precipitated based on the molar mass of manganese sulfate (MnSO4·H2O or MnSO4) (e.g., MnSO4·H2O is 169 g / mol, and the atomic mass of Mn is 55 g / mol): mprecipitate = m product × (55 / molar mass of manganese sulfate); Crystallization rate calculation: Crystallization rate = (mprecipitated / mtotal) × 100%.

[0080] Fixed carbon refers to the remaining components (mainly carbon element) in graphite after removing moisture, ash, and volatile matter. Its content is calculated as 100% - moisture content % - ash content % - volatile matter content %, and is obtained according to GB / T3521-2023 "Methods for Chemical Analysis of Graphite".

[0081] Example 1 A method for recovering lithium nickel cobalt manganese oxide, the specific process of which is as follows: Raw materials: Ternary battery powder (Ni 17.5%, Co 6.7%, Mn 8.8%, Li 3.9%, negative electrode 41%, Cu 1.5%, Al 1.2%).

[0082] Step S1: The raw material is scrapped ternary lithium batteries obtained from the market, with LiNi as the main component. 0.5 Co 0.2 Mn 0.3 O2 and toner.

[0083] Step S2: The raw materials are roasted at 450℃, with natural gas introduced in a counter-current manner during the roasting process. The amount of natural gas used is 4% of the weight of manganese (in the raw materials). The roasting time is 300 minutes.

[0084] Step S3: The roasted material is ball-milled to make a slurry. The particle size of the material is controlled at -120~-300 mesh, and the solid-liquid ratio of the finely ground slurry is controlled at 1:4.

[0085] Step S4: Add sulfuric acid to the slurry to adjust the pH of the slurry to 2.0, filter and separate the filter cake, and wash the filter cake to obtain a mixed solution of lithium sulfate and manganese sulfate, and obtain a nickel-cobalt filter cake. Return the washing water to this step.

[0086] Step S5: Heat the lithium manganese sulfate solution to 60°C, add calcium carbonate to adjust the pH of the solution to 4.5, keep it at this temperature for 300 minutes, and filter to obtain the lithium manganese sulfate solution and iron-aluminum-silicon slag.

[0087] Step S6: Detect the nickel and cobalt content in the lithium sulfate solution. Heat the lithium manganese sulfate solution to 95°C, add manganese sulfide or sodium sulfide at 1.2 times the molar amount of nickel and cobalt, react for 120 minutes, and filter to obtain lithium manganese sulfate solution and nickel and cobalt slag.

[0088] Step S7: Extract calcium and aluminum impurities from lithium manganese sulfate solution using P204.

[0089] Step S8: After concentrating the lithium manganese sulfate solution to a manganese concentration of 80 g / L, heat it to 200°C in a pressure vessel and hold it at that temperature for 30 minutes before discharging it into a continuous centrifuge. Wet manganese sulfate crystals (80% crystallization rate) are obtained, and after drying, the manganese sulfate product is obtained. Sodium hydroxide is added to the centrifuged liquid to adjust the pH to 11, and air is purged simultaneously for 240 minutes. After filtration and washing, wet manganese tetroxide is obtained, yielding a lithium sulfate solution (used for the production of lithium carbonate).

[0090] Step S9: Add sulfuric acid to the nickel-cobalt filter cake obtained in step S4 to adjust the pH to 1.0, react at 80°C for 120 minutes, check the pH every 30 minutes during the reaction process, and add more if the pH is insufficient, filter to obtain a nickel-cobalt sulfate mixture and leaching residue.

[0091] Step S10: The leaching residue obtained in step nine is mixed with sulfuric acid at a solid-liquid ratio of 1:2 to form a slurry, which is then added to a concentration of 150 g / L. The mixture is heated to 90°C and reacted for 6 hours. After filtration and washing, a nickel-cobalt sulfate mixture is obtained (return to step S9). The resulting wet graphite powder is washed with twice its weight of water, and the wash water is reused in this step. The wet graphite powder is dried at 200°C for 240 minutes to obtain the graphite powder product with a fixed carbon content of 98.2%.

[0092] Step S11: Extract the nickel-cobalt sulfate mixture obtained in step S9 using P204 to remove impurities such as calcium, manganese, aluminum, iron, and copper, to obtain the nickel-cobalt sulfate mixture.

[0093] Step S12: Use P507 to separate and extract cobalt, obtain cobalt sulfate solution, evaporate and crystallize to obtain cobalt sulfate product.

[0094] Step S13: Extract nickel with P507 to obtain nickel sulfate solution, then evaporate and crystallize to obtain nickel sulfate product.

[0095] Example 2 A method for recovering lithium nickel cobalt manganese oxide, the specific process of which is as follows: Raw materials: Ternary battery powder (Ni 11%, Co 11%, Mn 11%, Li 3.9%, negative electrode 41%, Cu 1%, Al 2.1%).

[0096] Step S1: The raw material is scrapped ternary lithium batteries obtained from the market, with LiNi as the main component. 0.33 Co 0.33 Mn 0.33 O2 and toner.

[0097] Step S2: The raw material is roasted at 650℃, with natural gas introduced in a counter-current manner during the roasting process. The amount of natural gas used is 6% of the weight of manganese (in the raw material). The roasting time is 100 minutes.

[0098] Step S3: The roasted material is ball-milled to make a slurry. The particle size of the material is controlled at -120~-300 mesh, and the solid-liquid ratio of the finely ground slurry is controlled at 1:3.

[0099] Step S4: Add sulfuric acid to the slurry to adjust the pH of the slurry to 3.0, filter and separate the filter cake, and wash the filter cake to obtain a mixed solution of lithium sulfate and manganese sulfate, and obtain a nickel-cobalt filter cake. Return the washing water to this step.

[0100] Step S5: Heat the lithium manganese sulfate solution to 70°C, add calcium carbonate to adjust the pH of the solution to 5.5, keep it at this temperature for 200 minutes, and filter to obtain the lithium manganese sulfate solution and iron-aluminum-silicon slag.

[0101] Step S6: Detect the nickel and cobalt content in the lithium sulfate solution. Heat the lithium manganese sulfate solution to 90°C, add manganese sulfide or sodium sulfide at 1.1 times the molar amount of nickel and cobalt, react for 150 minutes, and filter to obtain lithium manganese sulfate solution and nickel and cobalt slag.

[0102] Step S7: Extract calcium and aluminum impurities from lithium manganese sulfate solution using P507.

[0103] Step S8: After concentrating the lithium manganese sulfate solution to a manganese concentration of 100 g / L, heat it to 210°C in a pressure vessel and hold it at that temperature for 30 minutes. Then, discharge the solution into a continuous centrifuge. Wet manganese sulfate crystals are obtained (crystallization rate 84%). After drying, the manganese sulfate product is obtained. Sodium hydroxide is added to the centrifuged liquid to adjust the pH to 12, and air is purged simultaneously for 300 minutes. After filtration and washing, wet manganese tetroxide is obtained, yielding a lithium sulfate solution (used for the production of lithium carbonate).

[0104] Step S9: Add sulfuric acid to the nickel-cobalt filter cake obtained in step S4 to adjust the pH to 1.1, react at 80°C for 150 minutes, check the pH every 30 minutes during the reaction process and add more if it is insufficient, filter to obtain a nickel-cobalt sulfate mixture and leaching residue.

[0105] Step S10: The leaching residue obtained in step nine is slurried at a solid-liquid ratio of 1:2.5, sulfuric acid is added to a concentration of 200 g / L, and the mixture is heated to 95°C for 4 hours. The residue is filtered and washed to obtain a nickel-cobalt sulfate mixture (return to step S9). The resulting wet graphite powder is washed with twice its weight of water, and the wash water is reused in this step. The wet graphite powder is dried at 300°C for 200 minutes to obtain the graphite powder product with a fixed carbon content of 98.5%.

[0106] Step S11: Extract the nickel-cobalt sulfate mixture obtained in step S9 using P507 to remove impurities such as calcium, manganese, aluminum, iron, and copper, to obtain the nickel-cobalt sulfate mixture.

[0107] Step S12: Use P507 to separate and extract cobalt, obtain cobalt sulfate solution, evaporate and crystallize to obtain cobalt sulfate product.

[0108] Step S13: Extract nickel with P507 to obtain nickel sulfate solution, then evaporate and crystallize to obtain nickel sulfate product.

[0109] Example 3 A method for recovering lithium nickel cobalt manganese oxide, the specific process of which is as follows: Raw materials: Ternary electrode powder (Ni 36%, Co 12%, Mn 12%, Li 6.5%, Al 2.1%), black powder made from substandard positive electrode sheets from ternary lithium battery manufacturers. Because it does not contain carbon, carbon powder needs to be added.

[0110] Step S1: Add 14% of the weight of the raw material to carbon powder and mix evenly.

[0111] Step S2: The raw material is roasted at 750℃, with natural gas introduced in a counter-current manner during the roasting process. The amount of natural gas used is 8% of the weight of manganese (in the raw material). The roasting time is 60 minutes.

[0112] Step S3: The roasted material is ball-milled to make a slurry. The particle size of the material is controlled at -120~-300 mesh, and the solid-liquid ratio of the finely ground slurry is controlled at 1:6.

[0113] Step S4: Add sulfuric acid to the slurry to adjust the pH of the slurry to 4.0, filter and separate the filter cake, and wash the filter cake to obtain a mixed solution of lithium sulfate and manganese sulfate, and obtain a nickel-cobalt filter cake. Return the washing water to this step.

[0114] Step S5: Heat the lithium manganese sulfate solution to 80°C, add calcium carbonate to adjust the pH of the solution to 5.5, keep it at this temperature for 180 minutes, and filter to obtain the lithium manganese sulfate solution and iron-aluminum-silicon slag.

[0115] Step S6: Detect the nickel and cobalt content in the lithium sulfate solution. Heat the lithium manganese sulfate solution to 85°C, add manganese sulfide or sodium sulfide at 1.5 times the molar amount of nickel and cobalt, react for 150 minutes, and filter to obtain lithium manganese sulfate solution and nickel and cobalt slag.

[0116] Step S7: Extract calcium and aluminum impurities from lithium manganese sulfate solution using P507.

[0117] Step S8: After concentrating the lithium manganese sulfate solution to a manganese concentration of 120 g / L, heat it to 220°C in a pressure vessel and maintain the temperature for 30 minutes before discharging it into a continuous centrifuge. Wet manganese sulfate crystals (87% crystallization rate) are obtained, and after drying, the manganese sulfate product is obtained. Sodium hydroxide is added to the centrifuged liquid to adjust the pH to 12, and air is purged simultaneously for 300 minutes. After filtration and washing, wet manganese tetroxide is obtained, yielding a lithium sulfate solution (used for the production of lithium carbonate).

[0118] Step S9: Add sulfuric acid to the nickel-cobalt filter cake obtained in step S4 to adjust the pH to 1.5, react at 90°C for 240 minutes, check the pH every 30 minutes during the reaction process, and add more if the pH is insufficient, filter to obtain a nickel-cobalt sulfate mixture and leaching residue.

[0119] Step S10: The leaching residue obtained in step nine is slurried at a solid-liquid ratio of 1:3, sulfuric acid is added to a concentration of 250 g / L, and the mixture is heated to 100°C for 6 hours. The residue is filtered and washed to obtain a nickel-cobalt sulfate mixture (return to step S9). The residue is washed with twice its weight of water, and the wash water is reused in this step. The wet residue powder is dried at 200°C for 200 minutes and returned to the batching process. (The resulting dry powder is not graphite powder but unreacted carbon powder).

[0120] Step S11: Extract the nickel-cobalt sulfate mixture obtained in step S9 using P507 to remove impurities such as calcium, manganese, aluminum, iron, and copper, to obtain the nickel-cobalt sulfate mixture.

[0121] Step S12: Use P507 to separate and extract cobalt, obtain cobalt sulfate solution, evaporate and crystallize to obtain cobalt sulfate product.

[0122] Step S13: Extract nickel with P507 to obtain nickel sulfate solution, then evaporate and crystallize to obtain nickel sulfate product.

[0123] As can be seen from Examples 1 to 3: The raw material compositions of the three embodiments differed significantly, but the processes all operated stably, demonstrating the strong adaptability of the recovery method to raw materials. Ingredient differences: Example 1: The raw material is LiNi 0.5 Co 0.2 Mn 0.3 The O2 system has a high nickel content (17.5%) and a low cobalt content (6.7%). Example 2: The raw material is LiNi 0.33 Co0.33 Mn 0.33 O2 system, with balanced nickel, cobalt and manganese content (11% each). Example 3 uses a high nickel-cobalt-manganese content system (Ni 36%, Co 12%, Mn 12%) and does not contain negative electrode carbon powder, so an additional 14% carbon powder needs to be added.

[0124] By adjusting parameters such as the amount of carbon powder added (additional addition in Example 3), the amount of natural gas used (4%-8%), and the calcination temperature (450℃-750℃), it is possible to adapt to raw materials (ternary battery powder, ternary electrode powder) with different nickel-cobalt-manganese ratios and carbon content without changing the core process steps, thus solving the pain point of traditional processes being sensitive to the composition of raw materials.

[0125] The method of this invention features flexible and adjustable process parameters, with key parameters positively correlated with recovery efficiency. In the embodiments, the adjustment of process parameters demonstrates a clear optimization logic, and the parameter ranges are positively correlated with the recovery efficiency. Calcination parameters: As the calcination temperature increased from 450℃ (Example 1) to 750℃ (Example 3), the calcination time was shortened from 300 min to 60 min, and the amount of natural gas used increased from 4% to 8% of the manganese mass. This reflects that high temperature and sufficient natural gas can improve calcination efficiency and shorten reaction time. Leaching and purification parameters: The leaching temperature (80℃-95℃), sulfuric acid concentration (150g / L-250g / L), and reaction time (4h-6h) were adjusted to adapt to the leaching difficulty of metal elements in different raw materials. For high-content metal raw materials (Example 3), a higher sulfuric acid concentration (250g / L) and temperature (100℃) were used to ensure thorough leaching. Crystallization and separation parameters: When the concentration of manganese sulfate was increased from 80 g / L (Example 1) to 120 g / L (Example 3), the crystallization rate increased from 80% to 87%, indicating that the concentration was positively correlated with the crystallization efficiency. Furthermore, the stable control of the pressurized and heat-preserving temperature (200℃-220℃) and the pH endpoint (11-12) ensured the separation effect of manganese tetroxide and lithium sulfate.

[0126] All three embodiments achieved the core objectives of full component recovery and high-purity products, and the data performance was stable.

[0127] In terms of metal recycling, nickel, cobalt, manganese, and lithium were all accurately separated, yielding nickel sulfate, cobalt sulfate, manganese sulfate, manganese tetroxide, and lithium sulfate (which can be used to produce lithium carbonate), respectively, with no waste of high-value metals. Regarding non-metal recycling, the graphite powder recovered in Examples 1 and 2 had fixed carbon contents of 98.2% and 98.5%, respectively. Unreacted carbon powder from Example 3 could be returned to the batching process for reuse, achieving carbon resource recycling.

[0128] The process of this invention, through a pretreatment design involving countercurrent roasting of carbon powder and natural gas, a purification logic of multi-stage purification and specialized separation, and an energy-saving design of multiple cycles, achieves full-component, high-purity, and low-cost recovery of lithium nickel cobalt manganese oxide waste with different compositions. Experimental data on raw material compatibility, parameter flexibility, and recovery stability verify the technical advantages of full-component recovery, thorough impurity removal, energy saving through recycling, and wide adaptability described in the specification, making it suitable for industrial-scale application.

[0129] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for recovering lithium nickel cobalt manganese oxide, characterized in that, Includes the following steps: S1: Mix the raw materials and toner powder evenly at a mass ratio of 1:(0.1-0.2) to obtain a mixture; S2: The mixture is roasted, with natural gas being introduced in a counter-current flow during the roasting process; S3: The material roasted in step S2 is ball-milled into a slurry; S4: After adjusting the pH of the slurry, the slurry is filtered and separated to obtain a solid product and a liquid product. The solid product is a nickel-cobalt filter cake, and the liquid product is a first mixed solution of lithium sulfate and manganese sulfate. The nickel-cobalt filter cake is washed. S5: Add calcium carbonate to the first mixed solution of lithium sulfate and manganese sulfate to react and remove aluminum, silicon and iron from the raw materials. Then filter to obtain a second mixed solution of lithium sulfate and manganese sulfate and aluminum-silicon-iron slag. S6: Add sulfide to the second mixed solution of lithium sulfate and manganese sulfate to react and remove nickel and cobalt. After the reaction, filter to obtain nickel and cobalt slag and a third mixed solution of lithium sulfate and manganese sulfate. S7: Extract the third mixed solution of lithium sulfate and manganese sulfate with P204 or P507 extractant to remove calcium and aluminum from the solution, and obtain a fourth mixed solution of lithium sulfate and manganese sulfate. S8: The fourth mixed solution of lithium sulfate and manganese sulfate is concentrated, then discharged under pressure and heat, centrifuged to obtain wet manganese sulfate crystals, dried to obtain manganese sulfate product, sodium hydroxide is added to the centrifuged liquid and air is introduced to precipitate, manganese tetroxide is obtained, and after filtration and washing, wet manganese tetroxide and lithium sulfate solution are obtained. S9: Add the nickel-cobalt sulfate high-acid mixture from step S10 to the nickel-cobalt filter cake from step S4 for leaching, and filter to obtain nickel-cobalt sulfate mixture and leaching residue; S10: Add high-concentration sulfuric acid to the leaching residue obtained in step S9, heat and leach, filter and wash to obtain a nickel-cobalt sulfate mixture and wet graphite powder, dry the wet graphite powder to obtain the graphite powder product, return the nickel-cobalt sulfate mixture to step S9, and reuse the washing water in this step. S11: Extract the nickel-cobalt sulfate mixture obtained in step S9 using P204 or P507 extractant to obtain a nickel-cobalt sulfate mixture. S12: Use P507 or C272 to separate and extract cobalt to obtain a cobalt sulfate solution, then evaporate and crystallize to obtain the cobalt sulfate product; S13: Extract nickel with P507 to obtain nickel sulfate solution, then evaporate and crystallize to obtain nickel sulfate product.

2. The recycling method according to claim 1, characterized in that, The raw material is power battery powder or ternary electrode powder.

3. The recycling method according to claim 1, characterized in that, In step S2, the roasting temperature is 450-850℃; and / or, the roasting time is 30-300 min; and / or, the roasting atmosphere is natural gas; and / or, the amount of natural gas used is 4-20% of the manganese mass in the raw material.

4. The recycling method according to claim 1, characterized in that, In step S3, the particle size of the ball milling slurry is -120 to -300 mesh; and / or, after the ball milling slurry is completed, the solid-liquid ratio of the slurry is 1:(2~10).

5. The recycling method according to claim 1, characterized in that, In step S4, the pH of the slurry is adjusted to 2.0-5.0 by adding sulfuric acid, and the nickel-cobalt filter cake is washed. The wash water is then returned to this step.

6. The recycling method according to claim 1, characterized in that, In step S5, after adding calcium carbonate, the pH is controlled at 4.5-6.5; and / or, the reaction temperature is 60-80℃; and / or, the reaction time is 60-300 min.

7. The recycling method according to claim 1, characterized in that, In step S6, the sulfide includes manganese sulfide or sodium sulfide; and / or, the excess coefficient of the sulfide is 100%-200%; and / or, the reaction temperature is 60-95℃; and / or, the reaction time is 60-300 min; and / or, the pH of the reaction is 5.0-6.

0.

8. The recycling method according to claim 1, characterized in that, In step S8, the fourth mixed solution of lithium sulfate and manganese sulfate is concentrated to a concentration of 80-120 g / L; and / or, in step S8, the pressure holding temperature is 200-220℃; and / or, in step S8, the pressure holding time is 30-60 min; and / or, in step S8, sodium hydroxide is added to the centrifuged liquid for precipitation, and the pH endpoint is controlled at 11-12; and / or, in step S8, the reaction temperature for adding sodium hydroxide for precipitation is 60-90℃; and / or, in step S8, the amount of air introduced is 200-1000% of the theoretical amount of manganese hydroxide converted to manganese tetroxide.

9. The recycling method according to claim 1, characterized in that, In step S9, the leaching reaction temperature is 60-100℃; and / or, in step S9, the leaching reaction time is 60-600 min; and / or, in step S9, the final pH of the leaching reaction is 1.0-3.

0.

10. The recycling method according to claim 1, characterized in that, In step S10, the concentration of the high-concentration sulfuric acid is 100-300 g / L; and / or, in step S10, the solid-liquid ratio of the added high-concentration sulfuric acid is 1:(1.5-3.0); and / or, in step S10, the temperature of the heated leaching is 60-100℃; and / or, in step S10, the heating leaching time is 60-600 minutes; and / or, in step S10, the washing temperature of the filtered washing is 60-80℃; and / or, in step S10, the mass ratio of washing water to solid is (1.5~3.0):1.