Method for cooperatively treating soap residual liquid and graphite slag in lithium battery recovery

Abstract

The invention discloses a method for cooperatively treating soap residual liquid and graphite slag in lithium battery recovery. The method comprises the following steps: performing reduction roasting on ternary battery powder; carrying out nickel-cobalt-manganese leaching treatment on the lithium slag subjected to lithium extraction treatment; carrying out copper removal and iron and aluminum removal treatment on the nickel-cobalt-manganese leaching solution; performing nickel soap extraction separation on the nickel-cobalt-manganese pre-extraction liquid to obtain a separated product and soap conversion residual liquid; adding caustic soda liquid into the soap conversion residual liquid to adjust the pH value to 8-10, and filtering and separating to obtain soap conversion filter residues and a collecting agent; and the ternary leaching residues are subjected to graphite scavenging treatment, a collecting agent and a preset foaming agent are added according to the dosage in the graphite scavenging treatment, and graphite concentrate and scavenging tailings are obtained through flotation separation. According to the method, the soap conversion residual liquid is directly used as the flotation collecting agent, the leaching residues are converted into the high-value graphite product, and the economical efficiency of the whole process is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium batteries, in particular to a method for co-processing of residual liquid and graphite residue in lithium battery recycling. BACKGROUND

[0002] Currently, in the recycling technology of ternary lithium batteries, residual liquid and leaching residue are produced, and the treatment of residual liquid and leaching residue is independent of each other and has no certain relevance.

[0003] The traditional treatment scheme for the residual liquid (containing kerosene wastewater) is as follows: after the extraction and separation of main metals such as nickel and cobalt, the residual liquid is regarded as a kind of organic wastewater containing oil. It contains oil organic components (such as kerosene) entrained or dissolved, a small amount of residual metal ions and salts. The main goal of the current treatment of residual liquid is to remove the oil organic matter (kerosene) in it to meet the wastewater discharge or reuse standards. The conventional method for residual liquid requires physical demulsification and separation: through techniques such as standing and air flotation, the oil and water are separated, and part of the oil phase is recovered. Deep adsorption treatment of residual liquid: using activated carbon, special resin and other adsorbent materials to remove residual dissolved organic matter. This method has high cost, and the regeneration or disposal of saturated activated carbon itself becomes a new solid waste problem. High-level oxidation of residual liquid, etc.: using ozone, Fenton reagent and other oxidation methods to decompose organic matter, but the operation cost is high and secondary pollution may be caused.

[0004] The above treatment regards kerosene in the raffinate as a "pollutant" that needs to be removed at a cost. The treatment process consumes energy and adsorbent (such as activated carbon), and generates additional solid waste, which is a net cost unit on the recycling production line.

[0005] The traditional treatment scheme for leaching residue (graphite residue) is as follows: after the extraction of valuable metals, the leaching residue is mainly composed of graphite (carbon), but contains metal compounds (such as a small amount of unreacted nickel, cobalt and manganese elements) that have not been completely leached out, inorganic salts (such as calcium sulfate) and impurities such as silicon and aluminum. Traditionally, its value is greatly underestimated. The conventional disposal method of leaching residue is low-value utilization or landfill: the most common method is to use it as a cheap carbon source (such as for steel plants) or to simply process it into low-quality carbon additive, or even to directly fill it as general industrial solid waste. This method completely wastes the high-value potential of graphite itself. Attempts to purify leaching residue: a few attempts have been made to float and purify it to obtain higher purity graphite. However, in order to achieve the ideal flotation effect, new flotation collectors (such as kerosene) need to be purchased and added. This increases the raw material cost on the graphite production line.

[0006] That is, the current treatment of leaching residue either ignores its high-value potential, resulting in resource waste, or, when purification is carried out, it is not associated with the upstream process, and additional reagents (kerosene) are consumed. At the same time, regardless of which way, the trace valuable metals remaining in the tailings are usually not effectively recovered, resulting in the final loss of metal yield. SUMMARY

[0007] The purpose of the present application is to overcome the shortcomings of the prior art, and the present application provides a method for co-processing of transfer soap residue and graphite residue in lithium battery recycling, which converts leaching residue into high-value graphite products by directly using transfer soap residue as a flotation collector, thereby improving the economy of the whole process.

[0008] The present application provides a method for co-processing of transfer soap residue and graphite residue in lithium battery recycling, characterized in that the method comprises:

[0009] The ternary battery powder is subjected to reduction roasting, and the reduction roasted ternary lithium battery powder is subjected to lithium extraction treatment according to the sulfuric acid leaching method;

[0010] The lithium residue after lithium extraction treatment is subjected to nickel-cobalt-manganese leaching treatment to obtain ternary leaching residue and nickel-cobalt-manganese leaching solution;

[0011] The nickel-cobalt-manganese leaching solution is subjected to copper removal and iron-aluminum removal treatment to obtain nickel-cobalt-manganese pre-extraction solution;

[0012] The nickel-cobalt-manganese pre-extraction solution is subjected to nickel soap extraction separation to obtain separation products and transfer soap residue;

[0013] The transfer soap residue is added with liquid alkali to adjust the pH value to 8-10, and filtration separation is performed to obtain transfer soap filter residue and collector;

[0014] The ternary leaching residue is subjected to graphite scavenging treatment, and the collector and a preset frother are added according to the dosage in the graphite scavenging treatment, and graphite concentrate and scavenging tailings are obtained by flotation separation.

[0015] The method further comprises:

[0016] The scavenging tailings are added to the lithium residue after lithium extraction treatment for nickel-cobalt-manganese leaching treatment.

[0017] The method further comprises:

[0018] The graphite concentrate is subjected to filtration and drying treatment to obtain graphite powder.

[0019] The collector and the preset frother are added according to the dosage in the graphite scavenging treatment, which comprises:

[0020] The ternary leaching residue is treated according to a first slurry liquid-solid ratio, the collector and a preset foaming agent are added according to the dosage, and the flotation separation is carried out to obtain a scavenging concentrate and a scavenging tailings.

[0021] The scavenging concentrate is treated according to a second slurry liquid-solid ratio, the collector and a preset foaming agent are added according to the dosage, and the flotation separation is carried out to obtain a graphite concentrate and a graphite tailings.

[0022] The method further comprises:

[0023] The graphite tailings are added to the ternary leaching residue for graphite scavenging treatment.

[0024] The reduction roasting of the ternary battery powder comprises:

[0025] The ternary battery powder is placed in a corundum crucible, and then the corundum crucible is placed in an atmosphere reduction furnace with a preset roasting temperature and roasting time for roasting;

[0026] After the roasting is completed, the material in the crucible is taken out after the crucible is fully cooled under a protective hydrogen atmosphere.

[0027] The lithium extraction treatment of the reduction roasted ternary lithium battery powder according to the sulfuric acid leaching method comprises:

[0028] The reduction roasted ternary powder is added to deionized water and stirred in a stirrer;

[0029] Stirring is carried out based on a preset reaction time, a reaction temperature and a stirring rate, and concentrated sulfuric acid is added during the stirring process to control the solution PH to 5-8;

[0030] After the reaction is completed, the leaching solution is left to stand and naturally cooled to room temperature, the filtrate and the filter residue in the cooled leaching solution are separated by vacuum filtration, and the filter residue is washed with deionized water multiple times.

[0031] The nickel-cobalt-manganese leaching treatment of the lithium residue after the lithium extraction treatment comprises:

[0032] The lithium residue after the lithium extraction treatment is added to a reaction kettle, deionized water is added, the solution PH is adjusted by adding concentrated sulfuric acid, a certain amount of hydrogen peroxide is added, and stirring is carried out based on a reaction time and a stirring rate;

[0033] After filtration by a filter press, a filtrate and a ternary leaching residue are obtained.

[0034] The copper and iron-aluminum removal treatment of the nickel-cobalt-manganese leaching solution comprises:

[0035] Iron powder is added to the nickel-cobalt-manganese leaching solution according to a formula;

[0036] Based on a preset stirring reaction time, stirring is carried out, and sponge copper is filtered out based on filtrate parameter requirements.

[0037] Add hydrogen peroxide according to the formula and stir based on the preset stirring reaction time;

[0038] Add Ni(OH)2 to adjust the pH of the solution to 4-6 according to the preset temperature requirements, precipitate Fe3+ and Al3+ in the filtrate, and then separate the solid and liquid through a filter press. The filtrate is the pre-extraction liquid of nickel-cobalt-manganese.

[0039] The step of performing nickel soap extraction and separation on the pre-extraction solution of nickel-cobalt-manganese includes:

[0040] The nickel-cobalt-manganese pre-extraction solution was sequentially fed into the P204 extraction tank and the P507 extraction tank.

[0041] Saponification, soap conversion, extraction, back-extraction, and regeneration are carried out sequentially in the extraction tank, and the components in the pre-extraction liquid are separated in sequence to obtain: soap conversion residue, manganese sulfate solution, cobalt sulfate solution, and nickel sulfate solution.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] 1. Significant cost reduction and efficiency improvement: By directly using the soaping residue as a flotation collector, the cost of purchasing kerosene and the cost of deep oil removal from the soaping residue are eliminated. At the same time, the leaching residue is transformed into high-value graphite products, enabling the soaping residue to work synergistically with the leaching residue, thus improving the overall economic efficiency of the process.

[0044] 2. Achieved maximum recovery of valuable metals: By returning flotation tailings to the leaching process, residual nickel, cobalt, and manganese are recovered, increasing the total recovery rate of the main metals by about 1%, which improves the recovery rate of traditional processes.

[0045] 3. Maximized environmental benefits: Significantly reduced wastewater discharge and hazardous waste generation, and achieved full resource utilization of soaping residue and leaching residue, which is in line with the green and circular industrial policy.

[0046] 4. The overall process flow has been optimized: a collaborative treatment path for soap conversion residue and leaching residue has been created, simplifying the plant operation units and improving the stability and robustness of the system operation. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1This is a flowchart of the method for co-processing residual soap liquid and graphite slag in lithium battery recycling according to Embodiment 1 of the present invention;

[0049] Figure 2 This is a flowchart of the method for co-processing residual soap liquid and graphite slag in lithium battery recycling in Embodiment 2 of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Example 1

[0052] Specifically, Figure 1 A flowchart illustrating the method for co-treating residual soap solution and graphite slag during lithium battery recycling, as described in an embodiment of the present invention, is shown, specifically including:

[0053] S101. The ternary battery powder is reduced and roasted, and the reduced and roasted ternary lithium battery powder is subjected to lithium extraction treatment by sulfuric acid leaching.

[0054] It should be noted that the reduction roasting of ternary battery powder here includes: placing the ternary battery powder in an alumina crucible, then placing the alumina crucible in an atmosphere reduction furnace with a preset roasting temperature and roasting time for roasting; under a protective hydrogen atmosphere, after the crucible has cooled sufficiently after roasting, removing the material from the crucible.

[0055] It should be noted that the lithium extraction process of the reduced-calcined ternary lithium battery powder using the sulfuric acid leaching method here includes: adding the reduced-calcined ternary powder to deionized water and stirring in a stirrer; stirring based on a preset reaction time, reaction temperature, and stirring rate, and adding concentrated sulfuric acid during the stirring process to control the solution pH to 5-8; after the reaction is completed, the leachate is allowed to stand and naturally cooled to room temperature, and the filtrate in the cooled leachate is separated from the filter residue by vacuum filtration, and the filter residue is washed multiple times with deionized water.

[0056] S102. The lithium slag after lithium extraction is subjected to nickel-cobalt-manganese leaching treatment to obtain ternary leaching residue and nickel-cobalt-manganese leaching solution.

[0057] It should be noted that the nickel-cobalt-manganese leaching treatment of the lithium slag after lithium extraction includes: adding the lithium slag after lithium extraction into a reaction vessel, adding deionized water, adding concentrated sulfuric acid to adjust the pH of the solution, adding a certain amount of hydrogen peroxide, and stirring based on the reaction time and stirring rate; filtering through a filter press to obtain filtrate and ternary leaching residue.

[0058] S103. The nickel-cobalt-manganese leaching solution is subjected to copper removal and iron and aluminum removal treatment to obtain nickel-cobalt-manganese pre-extraction solution;

[0059] The copper and iron / aluminum removal treatment of the nickel-cobalt-manganese leaching solution includes: adding iron powder to the nickel-cobalt-manganese leaching solution according to a formula; stirring for a preset reaction time and filtering out sponge copper according to filtrate parameters; adding hydrogen peroxide according to a formula and stirring for a preset reaction time; adding Ni(OH)2 to adjust the solution pH to 4-6 according to a preset temperature requirement, and removing Fe from the filtrate. 3+ Al 3+ Precipitation is carried out, and solid-liquid separation is performed by a filter press. The filtrate is the pre-extraction liquid for nickel-cobalt-manganese.

[0060] S104. The nickel-cobalt-manganese pre-extraction liquid is subjected to nickel soap extraction and separation to obtain the separated product and the soap conversion residue.

[0061] It should be noted that the nickel soap extraction and separation of the nickel cobalt manganese pre-extraction liquid includes: feeding the nickel cobalt manganese pre-extraction liquid into the P204 extraction tank and the P507 extraction tank in sequence; saponification, soap conversion, extraction, back-extraction and regeneration are carried out in sequence in the extraction tank, and the components in the pre-extraction liquid are separated in sequence to obtain: soap conversion residue, manganese sulfate solution, cobalt sulfate solution and nickel sulfate solution.

[0062] S105. Add liquid alkali to the soap-converting residue to adjust the pH value to 8-10, and then filter and separate to obtain soap-converting filter residue and collector.

[0063] S106. The ternary leaching residue is subjected to graphite scavenging treatment, and the collector and the preset frother are added according to the dosage during the graphite scavenging treatment. Graphite concentrate and scavenging tailings are obtained by flotation separation.

[0064] It should be noted that the method also includes: adding the scavenged tailings to the lithium slag after lithium extraction for nickel-cobalt-manganese leaching treatment. Since the scavenged tailings also contain a small amount of metal, they are subjected to nickel-cobalt-manganese leaching treatment, thereby improving the refining efficiency of the metal to a certain extent.

[0065] It should be noted that the method also includes: filtering and drying the graphite concentrate to obtain graphite powder. This step allows the leaching residue to be converted into high-value graphite products.

[0066] It should be noted that the addition of the collector and the preset frother in the graphite scavenging process according to the dosage includes: after treating the ternary leaching residue according to the first slurry-liquid-solid ratio, adding the collector and the preset frother according to the dosage, and then separating by flotation to obtain scavenging concentrate and scavenging tailings; after treating the scavenging concentrate according to the second slurry-liquid-solid ratio, adding the collector and the preset frother according to the dosage, and then separating by flotation to obtain graphite concentrate and graphite tailings.

[0067] This method eliminates the cost of purchasing kerosene and the expense of deep oil removal from the soap-converting residue by directly using the residual soap liquor as a flotation collector. At the same time, it transforms the leaching residue into a high-value graphite product, enabling the residual soap liquor to work synergistically with the leaching residue and improving the overall economic efficiency of the process.

[0068] Example 2

[0069] Specifically, Figure 2 A flowchart illustrating the method for co-treating residual soap solution and graphite slag in lithium battery recycling according to an embodiment of the present invention is shown, specifically including the following:

[0070] S201, reduction roasting;

[0071] For example, 500g of ternary battery powder is placed in an alumina crucible, and then the alumina crucible is placed in an atmosphere reduction furnace with a preset calcination temperature and calcination time for calcination. Under a protective hydrogen atmosphere, the material is heated to the preset reaction temperature (600-800℃). After reaching the preset reaction temperature, the reaction time is set to 60-240min. After calcination is completed, the material in the crucible is removed after the crucible has cooled sufficiently.

[0072] The reaction equation in this step is as follows: 2LiMO2 + H2 → Li2O + 2MO + H2O.

[0073] S202, Lithium extraction by leaching

[0074] The reduced-calcined ternary powder was added to deionized water (solid-liquid mass ratio 1:3-6) and stirred in a stirrer for 60-240 min at a temperature of 70-80℃ and a stirring rate of 300-500 r / min. Concentrated sulfuric acid was added during stirring to maintain the pH of the solution at 5-8. After the reaction was complete, the leachate was allowed to stand and cool naturally to room temperature. The filtrate was then separated from the residue by vacuum filtration, and the residue was washed several times with deionized water.

[0075] The reaction equation is as follows: Li₂O + H₂SO₄ → Li₂SO₄ + H₂O

[0076] S203, nickel-cobalt-manganese leaching

[0077] Add the filter residue from S202 to the reactor, add deionized water (solid-liquid mass ratio of 1:3), add concentrated sulfuric acid to adjust the pH of the solution (1.5-3.0), add a small amount of hydrogen peroxide when the reaction temperature reaches 60-80℃, react for 120-240 min, stir at a rate of 50-300 r / min, filter through a filter press to obtain filtrate and filter residue (ternary leaching residue).

[0078] The reaction equation is as follows:

[0079] NiO + H₂SO₄ → NiSO₄ + H₂O

[0080] CoO + H₂SO₄ → CoSO₄ + H₂O

[0081] MnO + H₂SO₄ → MnSO₄ + H₂O

[0082] CuO + H₂SO₄ → CuSO₄ + H₂O

[0083] 2Fe 2+ +2H + +H₂O₂→2Fe 3+ +2H2O

[0084] Ni + H₂O₂ + H₂SO₄ → NiSO₄ + H₂O

[0085] Co + H₂O₂ + H₂SO₄ → CoSO₄ + H₂O

[0086] The main components of the filtrate are nickel-cobalt-manganese leaching solution; minor components include copper ions, iron ions, and aluminum ions.

[0087] The main component of the filter residue is graphite; trace components include nickel, cobalt, manganese, and silicates.

[0088] S204, nickel-cobalt-manganese leaching solution for copper removal

[0089] Add iron powder to the S203 filtrate according to the formula (m iron: m copper = 1.2~1.5, where m represents the mass ratio), stir and react for 60~120 min, then filter to obtain sponge copper and copper-removed filtrate (the filtrate should have Cu < 0.001-0.02 g / L).

[0090] CuSO4 + Fe → FeSO4 + Cu

[0091] S205, copper removal solution for iron and aluminum removal

[0092] Add hydrogen peroxide (m2 7.5% hydrogen peroxide: miron = 2-6) to the filtrate of S204 according to the formula, and stir for 45-90 minutes; raise the temperature to 60-85℃, add Ni(OH)2 to adjust the pH of the solution to 4-6, and remove the Fe from the filtrate. 3+ Al3+ Precipitation is carried out, and solid-liquid separation is performed using a filter press. The filtrate is a pre-extraction solution for nickel, cobalt, and manganese, with Fe < 0.002-0.02 g / L and Al < 0.002-0.02 g / L.

[0093] The reaction equation is as follows:

[0094] 3Ni(OH)2+Fe2(SO4)3→3NiSO4+2Fe(OH)3

[0095] 3Ni(OH)2+Al2(SO4)3→3NiSO4+2Al(OH)3

[0096] S206, nickel-cobalt-manganese pre-extraction solution, nickel soap extraction separation

[0097] The nickel-cobalt-manganese pre-extraction solution of S205 is sequentially fed into the P204 extraction tank and the P507 extraction tank. Saponification, soap conversion, extraction, back-extraction, and regeneration are carried out sequentially in the extraction tanks. The components in the pre-extraction solution are separated sequentially to obtain: soap conversion residue (the pre-extraction solution is nickel sulfate), manganese sulfate solution, cobalt sulfate solution, and nickel sulfate solution.

[0098] The reaction equation is as follows:

[0099] P₂O₄⁻H⁺NaOH→P₂O₄⁻Na⁺H₂O

[0100] 2P204-Na+NiSO4→2P204-Ni+Na2SO4

[0101] 2P204-Mn+H2SO4→2P204-H+MnSO4

[0102] P507-H+NaOH→P507-Na+H2O

[0103] 2P507-Na+NiSO4→2P507-Ni+Na2SO4

[0104] 2P507-Ni+CoSO4→2P507-Co+NiSO4

[0105] The main component of the soap-making residue is sodium sulfate solution, which contains trace amounts of nickel and oily organic matter (kerosene).

[0106] S207, Pretreatment of soap transfer residue

[0107] The soap-converting residue from step S206 is introduced into the reactor, liquid alkali is added to adjust the pH to 8-10, and the mixture is filtered and separated. The filter residue is nickel hydroxide (recovered), and the filtrate is used as a collector in graphite flotation (kerosene content is about 1000 ppm).

[0108] NiSO4 + 2NaOH → Ni(OH)2 + Na2SO4

[0109] S208, Graphite Scavenging (Principle: Graphite combines with the collector and floats to the surface as bubbles rise in the flotation machine, eventually being scraped away to form flotation concentrate; other components with low floatability form the underflow, known as flotation tailings)

[0110] Here, the ternary leaching residue from S203, as well as the tailings from S109 and S110, are slurried with a liquid-to-solid ratio of 3–6:1. Collectors (20–200 ppm) are added sequentially according to dosage, and then pumped into the flotation machine, followed by the addition of frothers (20–200 ppm). The scavenging concentrate and scavenging tailings are separated by flotation. The scavenging tailings are filtered to obtain graphite tailings slag (with a high metal content of approximately 0.5–1.5% Ni), which is returned to S103 for heavy metal recovery.

[0111] Graphite scavenging achieves high graphite recovery rates, separates scavenged concentrate from tailings, allows for centralized recovery of graphite from scavenged concentrate, and simultaneously recovers heavy metals from the separated tailings.

[0112] S209, Graphite Select 1

[0113] The flotation concentrate from step S209 is pulped to a liquid-solid ratio of (3-6:1), and collector (20-200 ppm) and inhibitor (10-150 ppm) are added sequentially according to dosage. After being pumped into the flotation machine, frother (20-200 ppm) is added. The concentrate and tailings are obtained by flotation separation.

[0114] S210, Graphite Select 2

[0115] The S210 flotation concentrate is pulped to a liquid-solid ratio of 3-6:1. Collector (20-200 ppm) and inhibitor (10-150 ppm) are added sequentially according to dosage. After being pumped into the flotation machine, frother (20-200 ppm) is added. The concentrate and tailings are obtained by flotation separation. The concentrate is filtered and dried to obtain graphite powder.

[0116] The tailings from S209 and S210 can be combined with the ternary leaching residue for graphite scavenging in S208, thereby achieving a refining process for product recovery and improving the recovery efficiency of graphite powder. Through multiple graphite beneficiation processes, the overall graphite recovery content is increased. Because the entire recovery process is a streamlined operation with multi-stage beneficiation, the overall precision of the graphite powder is higher.

[0117] This method directly uses the soap-converting residue as a flotation collector, eliminating the cost of purchasing kerosene and the expense of deep oil removal from the residue. Simultaneously, it converts the leaching residue into high-value graphite, enabling synergistic processing of the residue and improving the overall economic efficiency. By returning the flotation tailings to the leaching process to recover residual nickel, cobalt, and manganese, the total recovery rate of the main metals is increased by approximately 1%, surpassing the recovery rate of traditional processes. It significantly reduces wastewater discharge and hazardous waste generation, achieving full resource utilization of both the soap-converting residue and the leaching residue, aligning with green and circular industrial policies. This synergistic treatment pathway for the soap-converting residue and leaching residue simplifies plant operations and enhances system stability and robustness.

[0118] Example 3

[0119] Based on the method steps of Examples 1 and 2, the reaction parameters in Examples 1-4 are detailed in the following table:

[0120]

[0121] Example 1

[0122] After reduction roasting, lithium extraction by leaching, nickel-cobalt-manganese leaching, copper removal, iron and aluminum removal, nickel soap extraction, and pretreatment of the residual liquid after soap conversion, the graphite flotation preparation conditions are as follows: the liquid-to-solid ratio of flotation is 4, and no inhibitor is added during scavenging; the frother for graphite concentrate 1 is 25 ppm, and the frother for graphite concentrate 2 is 25 ppm. 200 kg of battery powder is produced under these conditions.

[0123] The graphite powder has a purity of 98.52% and a nickel content as low as 0.05%. The return rate of the selected tailings is 36%, the return rate of the scavenged tailings is 24%, the total yield of nickel, cobalt and manganese is 99.7%, and the remaining amount of soap-making residue is 30%.

[0124] Example 2

[0125] After reduction roasting, lithium extraction by leaching, nickel-cobalt-manganese leaching, copper removal, iron and aluminum removal, nickel soap extraction, and pretreatment of the residual liquid after soap conversion, the graphite flotation preparation conditions are as follows: the liquid-to-solid ratio of flotation is 4, and no inhibitor is added during scavenging; the frother for graphite concentrate 1 is 25 ppm, and the frother for graphite concentrate 2 is 25 ppm. 200 kg of battery powder is produced under these conditions.

[0126] The graphite powder has a purity of 97.69% and a nickel content as low as 0.11%. The return rate of the selected tailings is 45%, the return rate of the scavenged tailings is 21%, the total yield of nickel, cobalt and manganese is 99.2%, and the remaining amount of soap-making residue is 15%.

[0127] Example 3

[0128] After reduction roasting, lithium extraction by leaching, nickel-cobalt-manganese leaching, copper removal, iron and aluminum removal, nickel soap extraction, and pretreatment of the residual liquid after soap conversion, the graphite flotation preparation conditions are as follows: the liquid-to-solid ratio of flotation is 4, and no inhibitor is added during scavenging; the frother for graphite concentrate 1 is 25 ppm, and the frother for graphite concentrate 2 is 25 ppm. 200 kg of battery powder is produced under these conditions.

[0129] The graphite powder has a purity of 98.12% and a nickel content as low as 0.08%. The return rate of the selected tailings is 40%, the return rate of the scavenged tailings is 23%, the total yield of nickel, cobalt and manganese is 99.5%, and the remaining amount of soap-making residue is 25%.

[0130] Example 4

[0131] After reduction roasting, lithium extraction by leaching, nickel-cobalt-manganese leaching, copper removal, iron and aluminum removal, nickel soap extraction, and pretreatment of the residual liquid after soap conversion, the graphite flotation preparation conditions are as follows: the liquid-to-solid ratio of flotation is 4, and no inhibitor is added during scavenging; the frother for graphite concentrate 1 is 25 ppm, and the frother for graphite concentrate 2 is 25 ppm. 200 kg of battery powder is produced under these conditions.

[0132] The graphite powder has a purity of 98.06% and a nickel content as low as 0.09%. The return rate of the selected tailings is 38%, the return rate of the scavenged tailings is 23%, the total yield of nickel, cobalt and manganese is 99.4%, and the remaining amount of soap-making residue is 26%.

[0133] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for co-treating residual soap solution and graphite slag in lithium battery recycling, characterized in that, The method includes: The ternary lithium battery powder was subjected to reduction roasting, and the reduced roasted ternary lithium battery powder was subjected to lithium extraction treatment by sulfuric acid leaching. The lithium slag after lithium extraction was subjected to nickel-cobalt-manganese leaching treatment to obtain ternary leaching residue and nickel-cobalt-manganese leaching solution. The nickel-cobalt-manganese leaching solution is subjected to copper removal and iron and aluminum removal treatment to obtain nickel-cobalt-manganese pre-extraction solution; The nickel-cobalt-manganese pre-extraction liquid was subjected to nickel soap extraction to separate the product and the soap-conversion residue. The pH value of the soap-converting residue is adjusted to 8-10 by adding liquid alkali, and then filtered to separate the soap-converting residue and the collector. The ternary leaching residue is subjected to graphite scavenging treatment, and the collector and the preset frother are added in the graphite scavenging treatment according to the dosage. Graphite concentrate and scavenging tailings are obtained by flotation separation.

2. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The method further includes: The scavenged tailings are added to the lithium slag after lithium extraction for nickel-cobalt-manganese leaching treatment.

3. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The method further includes: The graphite concentrate is filtered and dried to obtain graphite powder.

4. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The addition of the collector and the pre-set frother in the graphite scavenging process according to the dosage includes: After the ternary leaching residue is treated according to the first slurry liquid-solid ratio, the collector and the preset frother are added according to the dosage, and the scavenging concentrate and scavenging tailings are obtained by flotation separation. After the scavenged concentrate is treated according to the second slurry-liquid-solid ratio, the collector and the preset frother are added according to the dosage, and graphite concentrate and graphite tailings are obtained by flotation separation.

5. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 4, characterized in that, The method further includes: The graphite tailings are added to the ternary leaching residue and then subjected to graphite scavenging treatment.

6. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The reduction and calcination of the ternary battery powder includes: The ternary battery powder is placed in an alumina crucible, and then the alumina crucible is placed in an atmosphere reduction furnace with a preset calcination temperature and calcination time for calcination. Under a protective hydrogen atmosphere, after calcination and once the crucible has cooled sufficiently, the material in the crucible is removed.

7. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The lithium extraction process of the reduction-calcined ternary lithium battery powder by sulfuric acid leaching includes: Add the reduced and roasted ternary powder to deionized water and stir in a mixer; Stirring is performed based on preset reaction time, reaction temperature and stirring rate, and concentrated sulfuric acid is added during the stirring process to control the pH of the solution to 5-8; After the reaction is complete, the leachate is allowed to stand and naturally cooled to room temperature. The filtrate and filter residue in the cooled leachate are separated by vacuum filtration, and the filter residue is washed multiple times with deionized water.

8. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The nickel-cobalt-manganese leaching treatment of the lithium slag after lithium extraction includes: The lithium residue after lithium extraction is added to the reactor, deionized water is added, concentrated sulfuric acid is added to adjust the pH of the solution, a certain amount of hydrogen peroxide is added, and the mixture is stirred according to the reaction time and stirring rate. After filtration by a filter press, filtrate and ternary leaching residue are obtained.

9. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The copper and iron / aluminum removal treatment of the nickel-cobalt-manganese leaching solution includes: Iron powder was added to the nickel-cobalt-manganese leaching solution according to the formula. Stirring is performed based on a preset stirring reaction time, and sponge copper is filtered out based on filtrate parameter requirements. Add hydrogen peroxide according to the formula and stir based on the preset stirring reaction time; Add Ni(OH)2 to adjust the pH of the solution to 4-6 according to the preset temperature requirements, and remove Fe from the filtrate. 3+ Al 3+ Precipitation is carried out, and solid-liquid separation is performed by a filter press. The filtrate is the pre-extraction liquid for nickel-cobalt-manganese.

10. The method for co-treating residual soap solution and graphite slag during lithium battery recycling as described in claim 1, characterized in that, The step of performing nickel soap extraction and separation on the pre-extraction solution of nickel-cobalt-manganese includes: The nickel-cobalt-manganese pre-extraction solution was sequentially fed into the P204 extraction tank and the P507 extraction tank. Saponification, soap conversion, extraction, back-extraction, and regeneration are carried out sequentially in the extraction tank, and the components in the pre-extraction liquid are separated in sequence to obtain: soap conversion residue, manganese sulfate solution, cobalt sulfate solution, and nickel sulfate solution.

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