Method for full-chain integrated treatment of spent ternary lithium batteries

Abstract

The present disclosure belongs to the technical field of recycling of spent batteries. Disclosed is a method for full-chain integrated treatment of spent ternary lithium batteries. The method comprises the following steps: subjecting black mass in a spent ternary lithium battery to be treated and a reducing agent to first roasting, so as to obtain a first roasted product; subjecting the first roasted product to a lithium extraction treatment, and subjecting lithium-extracted residues obtained by means of the lithium extraction treatment to magnetic separation; subjecting a non-magnetic material obtained by means of the magnetic separation to first acid leaching and solid-liquid separation, so as to obtain first acid leaching residues; subjecting the first acid leaching residues to second roasting, so as to obtain a second roasted product; and subjecting graphite in the second roasted product to flotation. The method can at least efficiently recycle graphite in spent ternary lithium batteries, thereby avoiding the wasting of resources.

Description

A full-chain integrated method for processing waste ternary lithium batteries Technical Field

[0001] The present disclosure relates to the technical field of waste battery recycling and utilization, and in particular to a method for processing waste ternary lithium batteries in an integrated manner throughout the entire chain. Background Art

[0002] With the rapid development of the new energy vehicle industry in recent years, the production and demand for lithium-ion batteries have been growing. However, waste lithium-ion batteries contain large amounts of heavy metals and organic matter. If not recycled, they will cause significant environmental pollution and endanger human survival. Effective and green recycling of waste lithium batteries not only addresses environmental issues but also creates significant economic benefits by recovering valuable components from waste lithium batteries.

[0003] The traditional recycling process of waste ternary lithium batteries is mainly divided into pyrometallurgical process and wet process. The pyrometallurgical process is to melt the waste lithium batteries at high temperature to generate metal alloys, and then use wet process or electrolysis process to obtain products from the alloys; the wet process is to disassemble, crush and screen the waste ternary lithium batteries to obtain black powder, and then leach, remove impurities and extract the black powder.

[0004] However, whether it is a pyrometallurgical process or a wet process, it is difficult to effectively recycle the graphite in waste ternary lithium batteries.

[0005] In view of this, the present disclosure is proposed.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure includes providing a full-chain integrated method for processing waste ternary lithium batteries, which can at least effectively recycle graphite in waste ternary lithium batteries and avoid waste of resources.

[0008] The present disclosure can be implemented as follows:

[0009] The present disclosure provides a method for processing waste ternary lithium batteries in an integrated manner, comprising the following steps:

[0010] The battery black powder in the waste ternary lithium battery to be processed is subjected to a first roasting with a reducing agent to obtain a first roasting product; the first roasting product is subjected to lithium extraction treatment, and the lithium extraction residue obtained by the lithium extraction treatment is subjected to magnetic separation; the non-magnetic material separated by magnetic separation is subjected to a first acid leaching, solid-liquid separation, to obtain a first acid leaching residue; the first acid leaching residue is subjected to a second roasting to obtain a second roasting product from which amorphous carbon is removed; and graphite in the second roasting product is floated.

[0011] In an optional embodiment, the reducing agent includes at least one of coal powder, carbon powder and an organic carbon reducing agent;

[0012] And / or, the mass ratio of battery black powder to reducing agent is 100:2-100:15.

[0013] In an optional embodiment, the first roasting includes at least one of the following features:

[0014] Feature 1: The first roasting is carried out under oxygen-free conditions;

[0015] Feature 2: The temperature of the first calcination is 500℃-800℃;

[0016] Feature 3: The first roasting time is 30min-240min.

[0017] In an optional embodiment, the lithium extraction treatment includes: first subjecting the first roasted product to water leaching for lithium, and then subjecting the solid obtained by water leaching for lithium to acid leaching.

[0018] In an optional embodiment, during the water leaching of lithium, the mass ratio of the first roasted product to water is 1:3-1:15; and / or the time for water leaching of lithium is 10 min-120 min.

[0019] In an optional embodiment, the acid leaching process for lithium extraction includes at least one of the following features:

[0020] Feature 1: The acid used for acid leaching of lithium includes sulfuric acid;

[0021] Feature 2: The concentration of the acid used in the acid leaching process is 10g / L-100g / L, and the mass ratio of the acid used in the acid leaching process to the solid matter obtained by water leaching is 2:1-6:1;

[0022] Feature 3: The time for acid leaching of lithium is 10min-100min.

[0023] In an optional embodiment, the magnetic separation includes at least one of the following features:

[0024] Feature 1: Magnetic separation is carried out in magnetic separation columns;

[0025] Feature 2: The magnetic field strength used for magnetic separation is 2000GS-12000GS;

[0026] Feature 3: Magnetic separation is carried out in the presence of water, with a water volume of 10L / h-100L / h.

[0027] In an optional embodiment, the first acid leaching includes: pressure leaching the non-magnetic material with a first acid and a first oxidant.

[0028] In an optional embodiment, the first pickling process includes at least one of the following features:

[0029] Feature 1: The first acid includes sulfuric acid;

[0030] Feature 2: The mass ratio of the non-magnetic material to the first acid is 1:2-1:5, and the concentration of the first acid is 150g / L-400g / L;

[0031] Feature 3: The amount of the first oxidant is 0.5 to 3 times the molar amount of the metal contained in the non-magnetic material;

[0032] Feature 4: The first oxidant includes at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate;

[0033] Feature 5: The pressure of the first acid leaching is 0.4MPa-1.5MPa;

[0034] Feature 6: The first acid leaching time is 20min-120min.

[0035] In an optional embodiment, the second roasting includes at least one of the following features:

[0036] Feature 1: The second roasting is carried out under oxygen conditions;

[0037] Feature 2: The temperature of the second roasting is 300℃-550℃;

[0038] Feature 3: The second roasting time is 30min-180min.

[0039] In an alternative embodiment, flotation is performed in a flotation column.

[0040] In an optional embodiment, the floated graphite is repaired to obtain battery-grade graphite.

[0041] In an optional embodiment, the repair process includes coating the graphite with a carbonaceous material and then performing high-temperature carbonization.

[0042] In an alternative embodiment, the carbonaceous material comprises at least one of asphalt, glucose, and sucrose.

[0043] In an optional embodiment, the amount of carbon-containing material used is 2 wt%-15 wt% of the graphite.

[0044] In an optional embodiment, the high-temperature carbonization temperature is 800° C.-1500° C., and / or the high-temperature carbonization time is 30 min-240 min; and / or the high-temperature carbonization is performed in an oxygen-free atmosphere.

[0045] In an optional embodiment, the method further includes purifying the graphite before repairing.

[0046] In an alternative embodiment, the reagents used for purification include hydrochloric acid and nitric acid.

[0047] In an optional embodiment, the lithium extraction solution obtained by the lithium extraction process is subjected to lithium precipitation treatment to obtain a lithium-containing product.

[0048] In an optional embodiment, the magnetic material obtained by magnetic separation is subjected to a second acid leaching, solid-liquid separation, to obtain a second acid leaching liquid; the second acid leaching liquid is extracted and impurities removed to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0049] In an optional embodiment, the second acid leaching includes: leaching the magnetic material with a second acid and a second oxidant at normal pressure.

[0050] In an optional embodiment, the second pickling process includes at least one of the following features:

[0051] Feature 1: The second acid includes sulfuric acid;

[0052] Feature 2: The mass ratio of the magnetic material to the second acid is 1:2-1:5, and the concentration of the second acid is 150g / L-400g / L;

[0053] Feature 3: The amount of the second oxidant is 0.5 to 3 times the molar amount of the metal contained in the magnetic material;

[0054] Feature 4: The second oxidant includes at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate;

[0055] Feature 5: The second acid leaching time is 30min-240min.

[0056] In an optional embodiment, the extraction reagent used in the extraction of the second acid leaching solution includes at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2-ethylhexyl) phosphate and di(2,4,4-trimethylpentyl)phosphinic acid.

[0057] In an optional embodiment, the first acid leaching liquid obtained after the first acid leaching is subjected to impurity removal and extraction to obtain a second product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0058] In an optional embodiment, the extraction reagent used in the extraction of the first acid leaching solution includes at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2-ethylhexyl) phosphate and di(2,4,4-trimethylpentyl)phosphinic acid.

[0059] The beneficial effects of the present disclosure include: The present disclosure comprises the following steps: firstly calcining battery black powder from waste ternary lithium batteries with a reducing agent to obtain a first calcined product; then subjecting the first calcined product to a lithium extraction process, and then subjecting the resulting lithium extraction residue to magnetic separation; then subjecting the magnetically separated non-magnetic material to a first acid leaching process, followed by solid-liquid separation, to obtain a first acid leaching residue; then calcining the first acid leaching residue to a second calcination process to obtain a second calcined product; and finally, flotation of graphite from the second calcined product. This method can at least efficiently recover graphite from waste ternary lithium batteries, thus avoiding resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0061] FIG1 is a process flow chart of the method for processing waste ternary lithium batteries in an integrated manner in Example 1;

[0062] FIG2 is a SEM image of the battery-grade graphite product obtained in Example 1. DETAILED DESCRIPTION

[0063] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer were followed. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0064] The following is a detailed description of the full-chain integrated method for processing waste ternary lithium batteries provided by the present invention.

[0065] The present disclosure proposes a method for the full-chain integrated treatment of waste ternary lithium batteries, which may include the following steps: subjecting the battery black powder in the waste ternary lithium batteries to be treated to a first roasting with a reducing agent to obtain a first roasting product; subjecting the first roasting product to a lithium extraction treatment, and subjecting the lithium extraction residue obtained by the lithium extraction treatment to magnetic separation; subjecting the non-magnetic material separated by the magnetic separation to a first acid leaching, solid-liquid separation, and obtaining a first acid leaching residue; subjecting the first acid leaching residue to a second roasting to obtain a second roasting product; and floatation of graphite in the second roasting product.

[0066] For reference, the aforementioned waste ternary lithium batteries primarily refer to waste nickel-cobalt-manganese ternary lithium batteries. Battery black powder can be obtained by discharging, crushing, cracking, and screening the waste ternary lithium batteries to be processed. For example, the main components of this battery black powder include ternary positive electrode materials, graphite negative electrode materials, conductive agents, binders, and a small amount of current collectors (such as copper foil, aluminum foil, etc.).

[0067] In the present disclosure, the reducing agent used may illustratively but not limitatively include at least one of coal powder, carbon powder and an organic carbon reducing agent.

[0068] The mass ratio of battery black powder to reducing agent can be 100:2-100:15, such as 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:11, 100:12, 100:13, 100:14 or 100:15, or any other value within the range of 100:2-100:15. In some embodiments, the mass ratio of battery black powder to coal powder is 100:6.

[0069] In the present disclosure, the first calcination is performed under oxygen-free conditions, for example, under inert gas conditions or nitrogen conditions.

[0070] The temperature of the first calcination may be 500° C.-800° C., such as 500° C., 550° C., 600° C., 650° C., 700° C., 750° C. or 800° C., or any other value within the range of 500° C.-800° C. In some embodiments, the temperature of the first calcination is 650° C.

[0071] The time of the first roasting can be 30 min-240 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min or 240 min, or any other value within the range of 30 min-240 min. In some embodiments, the time of the first roasting is 180 min.

[0072] Continuing from the above, by reducing and roasting the battery black powder with a reducing agent (first roasting), most of the nickel and most of the cobalt in the battery black powder can be reduced to magnetic nickel and cobalt elements, which is beneficial for subsequent magnetic separation to obtain magnetic metal substances and non-magnetic graphite and other substances, thereby avoiding the influence of nickel and cobalt on the subsequent separation of graphite. In addition, the lithium contained in the battery black powder can form lithium-containing carbonates during the first roasting process, which is beneficial for effective leaching in the lithium extraction process, thereby avoiding the influence of lithium on the subsequent separation of graphite. It should be noted that manganese is still in the form of oxide at the first roasting temperature and will not be reduced to a single substance.

[0073] In the present disclosure, the lithium extraction process includes: first subjecting the first roasted product to water leaching for lithium, and then subjecting the solid obtained by water leaching for lithium to acid leaching.

[0074] For reference, during the water leaching of lithium, the mass ratio of the first calcined product to water can be 1:3-1:15, such as 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, or 1:15, or any other value within the range of 1:3-1:15. In some embodiments, the mass ratio of the first calcined product to water is 1:12.

[0075] The time for water leaching lithium can be 10 min to 120 min, such as 10 min, 20 min, 40 min, 60 min, 80 min, 100 min or 120 min, or any other value within the range of 10 min to 120 min. In some embodiments, the time for water leaching lithium is 90 min.

[0076] By carrying out water leaching of lithium according to the above conditions, most of the lithium can be leached out, and the purity of the leached lithium is relatively high, which is beneficial to reducing the subsequent impurity removal cost.

[0077] For reference, the acid used in the acid leaching process for lithium extraction includes sulfuric acid and the like.

[0078] The concentration of the acid used in the acid leaching process can be 10 g / L to 100 g / L, such as 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or 100 g / L, or any other value within the range of 10 g / L to 100 g / L. In some embodiments, the concentration of the acid used in the acid leaching process is 60 g / L.

[0079] The mass ratio of the acid used in the acid leaching process to the solids extracted by water leaching can be 2:1-6:1, such as 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, or 6:1, or any other value within the range of 2:1-6:1. In some embodiments, the mass ratio of the acid used in the acid leaching process to the solids extracted by water leaching is 1:3.

[0080] The time for acid leaching lithium can be 10 min to 100 min, such as 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min or 100 min, or any other value within the range of 10 min to 100 min. In some embodiments, the time for acid leaching lithium is 60 min.

[0081] By acid leaching lithium under the above conditions, the lithium remaining in the solid matter obtained by water leaching can be further effectively extracted.

[0082] As mentioned above, by first leaching lithium in water, most of the lithium can be selectively leached, while nickel, cobalt, and manganese are not leached in this process. Then, by acid leaching lithium, the lithium not leached in the water leaching stage can be further leached (due to the low concentration of acid used in the acid leaching process, nickel, cobalt, and manganese are basically not leached). The lithium extraction method of first leaching in water and then acid leaching can achieve a higher lithium leaching rate.

[0083] In the present disclosure, the lithium extraction slag obtained by the lithium extraction treatment is the leaching residue obtained after the above-mentioned acid leaching lithium extraction treatment, and the leaching residue includes magnetic materials (such as nickel, cobalt, manganese, etc.) and non-magnetic materials (such as graphite and non-magnetic oxides of nickel, cobalt, and manganese).

[0084] For reference, the magnetic separation of the magnetic material and the non-magnetic material can be performed in a magnetic separation column.

[0085] The magnetic field strength used for magnetic separation can be 2000GS-12000GS, such as 2000GS, 4000GS, 6000GS, 8000GS, 10000GS or 12000GS, or any other value within the range of 2000GS-12000GS. In some embodiments, the magnetic field strength used for magnetic separation is 10000GS.

[0086] The magnetic separation is carried out in the presence of water, that is, the leached residue obtained after the acid leaching treatment for lithium extraction is mixed with water and then subjected to magnetic separation. For example, the amount of water used during the magnetic separation process can be 10 L / h to 100 L / h, such as 10 L / h, 20 L / h, 30 L / h, 40 L / h, 50 L / h, 60 L / h, 70 L / h, 80 L / h, 90 L / h, or 100 L / h, or any other value within the range of 10 L / h to 100 L / h. In some embodiments, the amount of water used during the magnetic separation process is 60 L / h.

[0087] Continuing from the above, the magnetic separation process, utilizing the magnetic field of the magnetic separation column and gravity elutriation, effectively separates magnetic and non-magnetic materials. The magnetic materials are primarily nickel, cobalt, and manganese, and the impurity content in the leachate of the magnetic materials is greatly reduced. In addition to graphite, the non-magnetic materials also contain some unreduced nickel and cobalt (such as nickel oxide and cobalt oxide) and manganese oxide.

[0088] In the present disclosure, the first acid leaching includes: pressurizing and leaching the non-magnetic material with a first acid and a first oxidant.

[0089] The first acid used in this process includes sulfuric acid and the like.

[0090] The mass ratio of the non-magnetic material to the first acid can be 1:2-1:5, such as 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, or any other value within the range of 1:2-1:5. In some embodiments, the mass ratio of the non-magnetic material to the first acid is 1:3.

[0091] The concentration of the first acid can be 150 g / L-400 g / L, such as 150 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L or 400 g / L, or any other value within the range of 150 g / L-400 g / L. In some embodiments, the concentration of the first acid is 200 g / L.

[0092] The amount of the first oxidant can be 0.5 to 3 times the molar amount of the metal contained in the non-magnetic material, such as 0.5, 1, 1.5, 2, 2.5, or 3 times, or any other value within the range of 0.5 to 3 times. In some embodiments, the amount of the first oxidant is 1.2 times the molar amount of the metal contained in the non-magnetic material.

[0093] The first oxidant may illustratively include at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate.

[0094] For reference, the pressure of the first acid leaching can be 0.4 MPa-1.5 MPa, such as 0.4 MPa, 0.5 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa or 1.5 MPa, or any other value within the range of 0.4 MPa-1.5 MPa. In some embodiments, the pressure of the first acid leaching is 1 MPa.

[0095] The first acid leaching time can be 20 min-120 min, such as 20 min, 40 min, 60 min, 80 min, 100 min or 120 min, or any other value within the range of 20 min-120 min. In some embodiments, the first acid leaching time is 90 min.

[0096] After the first acid leaching, solid-liquid separation is performed to produce a first acid leaching residue and a first acid leaching solution. The first acid leaching residue primarily consists of graphite slag, along with a small amount of unleached metals such as nickel and cobalt, and their oxides. The first acid leaching solution primarily consists of nickel, cobalt, and manganese, including, for example, nickel sulfate, cobalt sulfate, and manganese sulfate.

[0097] As mentioned above, by subjecting the non-magnetic material to pressurized acid leaching according to the above conditions, most of the nickel, cobalt and manganese in the non-magnetic material can be leached, and it is beneficial to accelerate the leaching reaction rate and reduce the leaching time.

[0098] In some embodiments, the first acid leaching solution obtained by the first acid leaching may be further subjected to impurity removal and extraction to obtain a second product containing nickel sulfate, cobalt sulfate, and manganese sulfate.

[0099] For reference, the extraction reagent used in the first acid leaching solution for extraction may illustratively include at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate (i.e., extractant P507), di(2-ethylhexyl) phosphate (i.e., extractant P204), and di(2,4,4-trimethylpentyl)phosphinic acid (i.e., extractant C272). In some embodiments, the first acid leaching solution may be extracted using the above extraction reagents in a stepwise manner.

[0100] It should be noted that if the first acid leaching residue is directly subjected to flotation, it is difficult to effectively separate the graphite and amorphous carbon (such as the pulverized coal in the conductive agent and reducing agent) in the first acid leaching residue. Furthermore, the oxidation temperature of graphite is higher than that of amorphous carbon. Therefore, the present disclosure first calcines the first acid leaching residue for a second time before flotation.

[0101] For reference, the second calcination is performed under an aerobic condition, such as an air condition or an oxygen condition.

[0102] The temperature of the second calcination can be 300° C.-550° C., such as 300° C., 350° C., 400° C., 450° C., 500° C. or 550° C., or any other value within the range of 300° C.-550° C. In some embodiments, the temperature of the second calcination is 450° C.

[0103] The second calcination time is 30 min-180 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, 150 min or 180 min, etc., or any other value within the range of 30 min-180 min. In some embodiments, the second calcination time is 120 min.

[0104] Continuing from the above, a second roasting under the above conditions effectively removes amorphous carbon from the first acid leaching residue, improving the quality of the subsequent graphite concentrate. Furthermore, a small amount of unleached metals and oxides, such as nickel and cobalt, can be converted into metal oxides that are more reactive with acids (e.g., sulfuric acid) through the second roasting, facilitating subsequent purification and impurity removal.

[0105] In the present disclosure, flotation can be performed in a flotation column. The flotation reagents used in the flotation include a collector, a frother, and a regulator. The collector includes kerosene or diesel, and its usage is exemplarily 300 g / t; the frother includes pine oil or octanol, and its usage is exemplarily 120 g / t; and the regulator includes water glass or sodium hexametaphosphate, and its usage is exemplarily 1000 g / t.

[0106] It should be noted that the present disclosure adopts a flotation column for flotation, which has the following advantages over the conventional flotation machine: the graphite product obtained by the flotation column has a higher grade and a higher recovery rate.

[0107] The above flotation is beneficial to the recovery of fine-grained graphite and the improvement of the graphite recovery rate.

[0108] Furthermore, the floated graphite can be repaired to obtain battery-grade graphite.

[0109] For reference, the repair process may include coating the graphite with a carbonaceous substance followed by high-temperature carbonization.

[0110] The carbon-containing material may illustratively include at least one of asphalt, glucose and sucrose. In some embodiments, the carbon-containing material is asphalt.

[0111] For example, the amount of the carbon-containing material can be 2 wt% to 15 wt% of the graphite, such as 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, or 15 wt%, or any other value within the range of 2 wt% to 15 wt%. In some embodiments, the amount of the carbon-containing material is 6 wt% of the graphite.

[0112] The temperature of high-temperature carbonization can be 800° C.-1500° C., such as 800° C., 900° C., 1000° C., 1100° C., 1200° C., 1300° C., 1400° C., or 1500° C., or any other value within the range of 800° C.-1500° C. In some embodiments, the temperature of high-temperature carbonization is 1200° C.

[0113] The high temperature carbonization time can be 30 min-240 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min or 240 min, or any other value within the range of 30 min-240 min. In some embodiments, the high temperature carbonization time is 120 min.

[0114] The high-temperature carbonization is performed in an oxygen-free atmosphere (such as an inert atmosphere or a nitrogen atmosphere).

[0115] As mentioned above, by coating graphite with carbon-containing substances and then carbonizing it at high temperature, a battery-grade graphite product can be directly obtained, avoiding the high cost incurred by graphitizing graphite at conditions above 2500°C in the existing technology.

[0116] In some embodiments, the graphite may be purified prior to remediation.

[0117] For reference, the purification reagents used for purification may include hydrochloric acid and nitric acid.

[0118] The mass ratio of the purification reagent to graphite can be 2:1, the concentration of hydrochloric acid can be 200 g / L, the concentration of nitric acid can be 200 g / L, and the purification time can be 100 min.

[0119] Through purification to remove the remaining impurities contained in the graphite, the purity of the purified graphite can be as high as 99.9%.

[0120] Furthermore, in order to realize the recycling and utilization of all components of waste ternary lithium batteries, in the present disclosure, the lithium extraction liquid obtained by the lithium extraction process can also be subjected to lithium precipitation treatment to obtain a lithium-containing product.

[0121] The lithium extraction solution obtained by the above lithium extraction treatment is the leachate obtained after the acid leaching lithium treatment, and the main component of the leachate is lithium.

[0122] The precipitated lithium can be recovered by adding carbon dioxide or sodium carbonate to the lithium extraction solution and heating it for precipitation.

[0123] Furthermore, in order to achieve the recycling and utilization of all components of waste ternary lithium batteries, in the present disclosure, the magnetic material obtained by magnetic separation can also be subjected to a second acid leaching, solid-liquid separation, to obtain a second acid leaching liquid, and the second acid leaching liquid is extracted and impurities are removed to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0124] For reference, the second acid leaching includes leaching the magnetic material with a second acid and a second oxidant at normal pressure (eg, one atmosphere).

[0125] The second acid used in this process includes sulfuric acid, etc.

[0126] The mass ratio of the magnetic material to the second acid can be 1:2-1:5, such as 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, or any other value within the range of 1:2-1:5. In some embodiments, the mass ratio of the magnetic material to the second acid is 1:4.

[0127] The concentration of the second acid can be 150 g / L-400 g / L, such as 150 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L or 400 g / L, or any other value within the range of 150 g / L-400 g / L. In some embodiments, the concentration of the second acid is 300 g / L.

[0128] The amount of the second oxidant can be 0.5 to 3 times the molar amount of the metal contained in the magnetic material, such as 0.5, 1, 1.5, 2, 2.5, or 3 times, or any other value within the range of 0.5 to 3 times. In some embodiments, the amount of the second oxidant is 1.5 times the molar amount of the metal contained in the magnetic material.

[0129] The second oxidant may illustratively include at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate.

[0130] For reference, the second acid leaching time can be 30 min to 240 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min, or 240 min, or any other value within the range of 30 min to 240 min. In some embodiments, the second acid leaching time is 180 min.

[0131] As mentioned above, by subjecting the magnetic material to a second acid leaching, the risk of hydrogen generated when nickel metal and cobalt metal react with sulfuric acid can be avoided.

[0132] For reference, the extraction reagent used in the second acid leaching solution for extraction may illustratively include at least one of P507, P204, and C272. In some embodiments, the second acid leaching solution may be extracted using the above extraction reagents for stepwise extraction.

[0133] As mentioned above, the general process and principle of the above method provided by the present disclosure can be summarized as follows:

[0134] The present invention involves subjecting battery black powder to a first calcination (oxygen-free calcination) with a reducing agent, followed by step-by-step leaching and acid leaching to extract lithium. The lithium in the resulting lithium extraction solution is recovered by lithium precipitation, and the resulting lithium extraction residue is subjected to magnetic separation using a magnetic separation column to separate magnetic and non-magnetic materials. The magnetic material undergoes a second acid leaching (at normal pressure with an oxidant acid leaching) to produce a second acid leaching solution. The second acid leaching solution is then extracted and impurities removed to produce a first product containing nickel sulfate, cobalt sulfate, and manganese sulfate. The non-magnetic material undergoes a first acid leaching (at pressurized oxidant acid leaching) to produce a first leachate. The first leachate is then impurities removed and extracted to produce a second product containing nickel sulfate, cobalt sulfate, and manganese sulfate. The first leachate residue undergoes a second calcination (low-temperature oxygen calcination) to remove amorphous carbon and residual organic matter. The residue is then subjected to flotation on a flotation column to produce a primary graphite product. After purification, the primary graphite product is coated with a carbonaceous material (such as asphalt) and then subjected to high-temperature carbonization to produce battery-grade graphite. This method enables full resource utilization of the valuable components of battery black powder.

[0135] For reference, the lithium recovery rate corresponding to this method can be greater than 94%, the nickel and cobalt recovery rates can be greater than 97%, the manganese recovery rate can be greater than 96%, and the recovery rate of battery-grade graphite products can be greater than 80%.

[0136] The features and performance of the present disclosure are further described in detail below with reference to the embodiments.

[0137] Example 1

[0138] This embodiment provides a method for processing waste ternary lithium batteries in an integrated manner. Referring to FIG1 , the method includes the following steps:

[0139] S1: The waste nickel-cobalt-manganese ternary lithium batteries recycled by a company in Hunan are discharged, crushed, cracked and screened to obtain battery black powder.

[0140] S2: After the battery black powder and the coal powder are evenly mixed, a first roasting treatment is performed to obtain a first roasting product.

[0141] During the first calcination process, inert gas (argon) was passed to maintain an oxygen-free environment. The amount of coal powder added was 6 wt % of the battery black powder. The temperature of the first calcination was 650° C. and the time of the first calcination was 180 min.

[0142] S3: placing the first calcined product into a container for water leaching of lithium, and performing solid-liquid separation to obtain a solid.

[0143] The mass ratio of the first roasted product to water is 1:12, and the time for water leaching lithium is 90 minutes.

[0144] S4: The solid obtained by leaching lithium with water is mixed with sulfuric acid to carry out acid leaching of lithium, and the solid-liquid separation is carried out to obtain leaching residue and leachate.

[0145] The mass ratio of sulfuric acid used in the acid leaching process to the solid matter obtained by water leaching is 1:3, the sulfuric acid concentration is 60g / L, and the acid leaching time for lithium extraction is 60min.

[0146] S5: introducing carbon dioxide into the above leachate, heating and precipitating it, and then recovering it.

[0147] S6: adding the leached residue and water into a magnetic separation column for separation to obtain magnetic material and non-magnetic material.

[0148] The magnetic field strength of the magnetic separation column is 10000 GS, and the water consumption is 60 L / h.

[0149] S7: subjecting the magnetic material to a second acid leaching (normal pressure leaching) with sulfuric acid and hydrogen peroxide, and performing solid-liquid separation to obtain a second acid leaching solution.

[0150] In this step, the mass ratio of the magnetic material to sulfuric acid is 1:4, the concentration of sulfuric acid is 200 g / L, the amount of hydrogen peroxide used is 1.5 times the molar amount of the metal contained in the magnetic material, the pressure of the second acid leaching is 1 atmosphere, and the time of the second acid leaching is 180 minutes.

[0151] S8: extracting and removing impurities from the second acid leaching liquid to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0152] The extraction in this step is carried out by step extraction using P507, P204 and C272.

[0153] S9: performing a first acid leaching (pressure leaching) on ​​the non-magnetic material with sulfuric acid and hydrogen peroxide, and performing solid-liquid separation to obtain a first acid leaching residue and a first acid leaching liquid.

[0154] In this step, the mass ratio of the non-magnetic material to sulfuric acid is 1:3, the concentration of sulfuric acid is 200 g / L, the amount of hydrogen peroxide used is 1.2 times the molar amount of the metal contained in the non-magnetic material, the pressure of the first acid leaching is 1 MPa, and the time of the first acid leaching is 90 min.

[0155] S10: removing impurities and extracting the first acid leaching solution to obtain a second product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0156] This step is a stepwise extraction using P507, P204 and C272.

[0157] S11: The first acid leaching residue is subjected to a second roasting (low-temperature oxygen roasting).

[0158] Air was introduced during the second roasting, the temperature of the second roasting was 450° C., and the time of the second roasting was 120 min.

[0159] S12: The material obtained after the second roasting (second roasting product) is floated through a flotation column to obtain a primary graphite product.

[0160] The flotation reagents used in this step include a collector, a frother, and a regulator. The collector is kerosene at a dosage of 300 g / t, the frother is pine oil at a dosage of 120 g / t, and the regulator is water glass at a dosage of 1000 g / t.

[0161] S13: adding hydrochloric acid and nitric acid to purify the primary graphite product to obtain high-purity graphite.

[0162] The concentration of hydrochloric acid is 200 g / L, the concentration of nitric acid is 200 g / L, the mass ratio of the total amount of hydrochloric acid and nitric acid to the primary graphite product is 2:1, and the purification time is 100 minutes.

[0163] S14: mixing high-purity graphite with asphalt so that the asphalt coats the high-purity graphite, and then carbonizing the coated graphite at high temperature to obtain a battery-grade graphite product.

[0164] The addition amount of asphalt is 6wt% of the high-purity graphite. The high-temperature carbonization is carried out under oxygen-free conditions. The high-temperature carbonization temperature is 1200°C and the high-temperature carbonization time is 120 minutes.

[0165] The SEM image of the battery-grade graphite product obtained above is shown in FIG2 . It can be seen from the image that the graphite is in the form of flakes and fragments, has very little impurity content, and has a relatively smooth surface.

[0166] Example 2

[0167] The difference between this embodiment and embodiment 1 is that the temperature of the first calcination is 500°C.

[0168] Example 3

[0169] The difference between this embodiment and embodiment 1 is that the temperature of the second calcination is 300°C.

[0170] Example 4

[0171] The difference between this embodiment and embodiment 1 is that the temperature of the second calcination is 550°C.

[0172] Example 5

[0173] The difference between this embodiment and embodiment 1 is that the temperature of high-temperature carbonization is 1500°C.

[0174] Example 6

[0175] The difference between this embodiment and embodiment 1 is that the temperature of high-temperature carbonization is 800°C.

[0176] Example 7

[0177] This embodiment provides a method for processing waste ternary lithium batteries in an integrated manner, comprising the following steps:

[0178] S1: Discharge, crush, crack and screen the used nickel-cobalt-manganese ternary lithium batteries to obtain battery black powder.

[0179] S2: After the battery black powder and the coal powder are evenly mixed, a first roasting treatment is performed to obtain a first roasting product.

[0180] During the first calcination process, inert gas (nitrogen) was passed to maintain an oxygen-free environment, the amount of coal powder added was 2 wt % of the battery black powder, the temperature of the first calcination was 500° C., and the time of the first calcination was 240 min.

[0181] S3: placing the first calcined product into a container for water leaching of lithium, and performing solid-liquid separation to obtain a solid.

[0182] The mass ratio of the first roasted product to water is 1:5, and the time for water leaching lithium is 120 minutes.

[0183] S4: The solid obtained by leaching lithium with water is mixed with sulfuric acid to carry out acid leaching of lithium, and the solid-liquid separation is carried out to obtain leaching residue and leachate.

[0184] The mass ratio of sulfuric acid used in the acid leaching process to the solid matter obtained by water leaching is 1:2, the sulfuric acid concentration is 10 g / L, and the acid leaching time for lithium extraction is 100 minutes.

[0185] S5: Sodium carbonate is added to the above leachate, heated and precipitated, and then recovered.

[0186] S6: adding the leached residue and water into a magnetic separation column for separation to obtain magnetic material and non-magnetic material.

[0187] The magnetic field strength of the magnetic separation column is 5000 GS, and the water consumption is 100 L / h.

[0188] S7: subjecting the magnetic material to a second acid leaching (normal pressure leaching) with sulfuric acid and sodium sulfite, and performing solid-liquid separation to obtain a second acid leaching solution.

[0189] In this step, the mass ratio of the magnetic material to sulfuric acid is 1:2, the concentration of sulfuric acid is 150 g / L, the amount of sodium sulfite used is 0.5 times the molar amount of the metal contained in the magnetic material, the pressure of the second acid leaching is 1 atmosphere, and the time of the second acid leaching is 240 minutes.

[0190] S8: extracting and removing impurities from the second acid leaching liquid to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0191] This step is a stepwise extraction using P507, P204 and C272.

[0192] S9: performing a first acid leaching (pressure leaching) on ​​the non-magnetic material with sulfuric acid and sodium sulfite, and performing solid-liquid separation to obtain a first acid leaching residue and a first acid leaching liquid.

[0193] In this step, the mass ratio of the non-magnetic material to sulfuric acid is 1:2, the concentration of sulfuric acid is 150 g / L, the amount of sodium sulfite is 0.5 times the molar amount of the metal contained in the non-magnetic material, the pressure of the first acid leaching is 0.4 MPa, and the time of the first acid leaching is 120 min.

[0194] S10: removing impurities and extracting the first acid leaching solution to obtain a second product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0195] This step is a stepwise extraction using P507, P204 and C272.

[0196] S11: The first acid leaching residue is subjected to a second roasting (low-temperature oxygen roasting).

[0197] Oxygen was introduced during the second roasting, the temperature of the second roasting was 300° C., and the time of the second roasting was 180 min.

[0198] S12: The material obtained after the second roasting (second roasting product) is floated through a flotation column to obtain a primary graphite product.

[0199] The flotation reagents used in this step include a collector, a frother, and a regulator. The collector is kerosene at a dosage of 300 g / t, the frother is pine oil at a dosage of 120 g / t, and the regulator is water glass at a dosage of 1000 g / t.

[0200] S13: adding hydrochloric acid and nitric acid to purify the primary graphite product to obtain high-purity graphite.

[0201] The concentration of hydrochloric acid is 200 g / L, the concentration of nitric acid is 200 g / L, the mass ratio of the total amount of hydrochloric acid and nitric acid to the primary graphite product is 2:1, and the purification time is 100 minutes.

[0202] S14: mixing high-purity graphite with asphalt so that the asphalt coats the high-purity graphite, and then carbonizing the coated graphite at high temperature to obtain a battery-grade graphite product.

[0203] The addition amount of asphalt is 2wt% of the high-purity graphite. The high-temperature carbonization is carried out under oxygen-free conditions. The high-temperature carbonization temperature is 800°C and the high-temperature carbonization time is 240 minutes.

[0204] Example 8

[0205] This embodiment provides a method for processing waste ternary lithium batteries in an integrated manner, comprising the following steps:

[0206] S1: Discharge, crush, crack and screen the used nickel-cobalt-manganese ternary lithium batteries to obtain battery black powder.

[0207] S2: After the battery black powder and the coal powder are evenly mixed, a first roasting treatment is performed to obtain a first roasting product.

[0208] During the first calcination process, inert gas (argon) was passed to maintain an oxygen-free environment, the amount of coal powder added was 15 wt % of the battery black powder, the temperature of the first calcination was 800° C., and the time of the first calcination was 30 min.

[0209] S3: placing the first calcined product into a container for water leaching of lithium, and performing solid-liquid separation to obtain a solid.

[0210] The mass ratio of the first roasted product to water is 1:14, and the time for water leaching lithium is 10 minutes.

[0211] S4: The solid obtained by leaching lithium with water is mixed with sulfuric acid to carry out acid leaching of lithium, and the solid-liquid separation is carried out to obtain leaching residue and leachate.

[0212] The mass ratio of sulfuric acid used in the acid leaching process to the solid matter extracted by water leaching is 6:1, the sulfuric acid concentration is 100 g / L, and the acid leaching time for lithium extraction is 10 minutes.

[0213] S5: introducing carbon dioxide into the above leachate, heating and precipitating it, and then recovering it.

[0214] S6: adding the leached residue and water into a magnetic separation column for separation to obtain magnetic material and non-magnetic material.

[0215] The magnetic field strength of the magnetic separation column is 12000 GS, and the water consumption is 10 L / h.

[0216] S7: subjecting the magnetic material to a second acid leaching (normal pressure leaching) with sulfuric acid and sodium thiosulfate, and performing solid-liquid separation to obtain a second acid leaching solution.

[0217] In this step, the mass ratio of the magnetic material to sulfuric acid is 1:5, the concentration of sulfuric acid is 400 g / L, the amount of sodium thiosulfate used is 3 times the molar amount of the metal contained in the magnetic material, the pressure of the second acid leaching is 1 atmosphere, and the time of the second acid leaching is 30 minutes.

[0218] S8: extracting and removing impurities from the second acid leaching liquid to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0219] This step is a stepwise extraction using P507, P204 and C272.

[0220] S9: performing a first acid leaching (pressure leaching) on ​​the non-magnetic material with sulfuric acid and sodium thiosulfate, and separating the solid and liquid to obtain a first acid leaching residue and a first acid leaching liquid.

[0221] In this step, the mass ratio of the non-magnetic material to sulfuric acid is 1:5, the concentration of sulfuric acid is 400 g / L, the amount of sodium thiosulfate is 3 times the molar amount of the metal contained in the non-magnetic material, the pressure of the first acid leaching is 1.5 MPa, and the time of the first acid leaching is 20 min.

[0222] S10: removing impurities and extracting the first acid leaching solution to obtain a second product containing nickel sulfate, cobalt sulfate and manganese sulfate.

[0223] This step is a stepwise extraction using P507, P204 and C272.

[0224] S11: The first acid leaching residue is subjected to a second roasting (low-temperature oxygen roasting).

[0225] Air was introduced during the second roasting, the temperature of the second roasting was 550° C., and the time of the second roasting was 30 min.

[0226] S12: The material obtained after the second roasting (second roasting product) is floated through a flotation column to obtain a primary graphite product.

[0227] The flotation reagents used in this step include a collector, a frother, and a regulator. The collector is kerosene at a dosage of 300 g / t, the frother is pine oil at a dosage of 120 g / t, and the regulator is water glass at a dosage of 1000 g / t.

[0228] S13: adding hydrochloric acid and nitric acid to purify the primary graphite product to obtain high-purity graphite.

[0229] The concentration of hydrochloric acid is 200 g / L, the concentration of nitric acid is 200 g / L, the mass ratio of the total amount of hydrochloric acid and nitric acid to the primary graphite product is 2:1, and the purification time is 100 minutes.

[0230] S14: mixing high-purity graphite with asphalt so that the asphalt coats the high-purity graphite, and then carbonizing the coated graphite at high temperature to obtain a battery-grade graphite product.

[0231] The addition amount of asphalt is 15wt% of the high-purity graphite. The high-temperature carbonization is carried out under oxygen-free conditions. The high-temperature carbonization temperature is 1500°C and the high-temperature carbonization time is 30 minutes.

[0232] Comparative Example 1

[0233] The difference between this comparative example and Example 1 is that in S1, no reducing agent is added to reduce the battery black powder, but the battery black powder is directly subjected to the first calcination treatment.

[0234] Comparative Example 2

[0235] The difference between this comparative example and Example 1 is that the lithium extraction method is a two-stage water leaching process, that is, the water leaching of lithium is repeated twice (the process conditions for each water leaching of lithium are the same, all the same as S3 in Example 1), and acid leaching of lithium is not performed.

[0236] Comparative Example 3

[0237] This comparative example differs from Example 1 in that the leached residue obtained in S4 is not subjected to magnetic separation but directly to a second acid leaching (normal pressure leaching). The graphite recovery process in this comparative example is roughly as follows: first roasting - lithium extraction - first acid leaching - second roasting - flotation - purification - graphite repair.

[0238] Comparative Example 4

[0239] This comparative example differs from Example 1 in that the first acid leaching residue obtained in S9 is not subjected to a second roasting (low-temperature oxygen roasting) but is directly subjected to flotation. The graphite recovery process in this comparative example is roughly as follows: first roasting - lithium extraction - magnetic separation - first acid leaching - flotation - purification - graphite repair.

[0240] Comparative Example 5

[0241] The difference between this comparative example and Example 1 is that the second calcined product obtained in S11 is not subjected to flotation but is directly purified. The graphite recovery process in this comparative example is roughly as follows: first calcination - lithium extraction - magnetic separation - first acid leaching - second calcination - purification - graphite repair.

[0242] Comparative Example 6

[0243] The difference between this comparative example and Example 1 is that in S13, the primary graphite product is directly purified at a high temperature of 2600° C. without adding purification reagents such as hydrochloric acid and nitric acid.

[0244] Comparative Example 7

[0245] The difference between this comparative example and Example 1 is that a conventional flotation machine (XFDⅣ single-trough flotation machine produced by Jilin Prospecting Machinery Factory) is used for flotation instead of a flotation column.

[0246] Comparative Example 8

[0247] The difference between this comparative example and Example 1 is that the primary graphite product obtained in S11 is directly subjected to graphite repair without undergoing a purification process. The graphite recovery process in this comparative example is roughly as follows: first roasting - lithium extraction - magnetic separation - first acid leaching - second roasting - flotation - graphite repair.

[0248] Test example

[0249] ①. The recovery rates of Li, Ni, Co, Mn and C corresponding to the above Examples 1-8 and Comparative Examples 1-8 were tested, and the results are shown in Table 1.

[0250] Table 1 Example test results

[0251] As can be seen from Table 1, the method provided by the embodiment of the present disclosure can achieve higher recovery rates of Li, Ni, Co, Mn and C at lower costs.

[0252] ②. The battery-grade graphite product obtained in Example 1 was subjected to impurity content analysis, specific surface area measurement, and electrochemical analysis. The results are shown in Table 2.

[0253] The test method for electrical performance is as follows: using metallic lithium sheet as the counter electrode, PZ12 as the separator, 50μL of E30 as the electrolyte, the battery size is CR2430, and the battery structure is negative electrode shell-nickel foam-lithium sheet-electrolyte-separator-electrolyte-graphite electrode sheet-positive electrode shell. The battery is assembled into a battery, and at a current density of 10mA / g, a blue electric test cabinet is used to perform constant current cycle testing on the button half-cell between 0.005V and 1.5V to evaluate its electrochemical performance.

[0254] Table 2 Graphite product analysis of Example 1

[0255] It can be seen from Table 2 that the graphite product recovered in Example 1 of the present disclosure can meet the needs of battery preparation, and can be further used to prepare batteries with good capacity and initial efficiency. Industrial Applicability

[0256] The method for processing waste ternary lithium batteries provided by the present invention is simple to operate, can realize the full resource utilization of valuable components of battery black powder, and obtain a higher recovery rate of Li, Ni, Co, Mn and C at a lower cost.

Claims

1. A method for processing waste ternary lithium batteries in an integrated manner, characterized in that: The following steps are involved: The battery black powder in the waste ternary lithium battery to be treated is first roasted with a reducing agent to obtain a first roasted product; the first roasted product is subjected to lithium extraction treatment, and the lithium extraction slag obtained by the lithium extraction treatment is subjected to magnetic separation; the non-magnetic material separated by magnetic separation is subjected to a first acid leaching, solid-liquid separation, and a first acid leaching slag is obtained; the first acid leaching slag is second roasted to obtain a second roasted product with amorphous carbon removed; and graphite in the second roasted product is floated.

2. The method according to claim 1, characterized in that The reducing agent includes at least one of coal powder, carbon powder and organic carbon reducing agent; And / or, the mass ratio of the battery black powder to the reducing agent is 100:2-100:

15.

3. The method according to claim 1 or 2, characterized in that: The first roasting includes at least one of the following characteristics: Feature 1: The first roasting is carried out under oxygen-free conditions; Feature 2: The temperature of the first calcination is 500℃-800℃; Feature 3: The first roasting time is 30min-240min.

4. The method according to any one of claims 1 to 3, characterized in that: The lithium extraction process comprises: first subjecting the first roasted product to water leaching for lithium, and then subjecting the solid obtained by water leaching for lithium to acid leaching.

5. The method according to claim 4, characterized in that During the water leaching of lithium, the mass ratio of the first roasted product to water is 1:3-1:15; and / or the time for water leaching of lithium is 10 min-120 min.

6. The method according to claim 4, characterized in that The acid leaching process for lithium extraction includes at least one of the following features: Feature 1: The acid used for acid leaching of lithium includes sulfuric acid; Feature 2: The concentration of the acid used in the acid leaching process is 10g / L-100g / L, and the mass ratio of the acid used in the acid leaching process to the solid matter extracted by water leaching is 2:1-6:1; Feature 3: The time for acid leaching of lithium is 10min-100min.

7. The method according to any one of claims 1 to 6, characterized in that: Magnetic separation includes at least one of the following features: Feature 1: Magnetic separation is carried out in magnetic separation columns; Feature 2: The magnetic field strength used for magnetic separation is 2000GS-12000GS; Feature 3: Magnetic separation is carried out in the presence of water, with a water volume of 10L / h-100L / h.

8. The method according to any one of claims 1 to 7, characterized in that: The first acid leaching includes: pressurizing and leaching the non-magnetic material with a first acid and a first oxidant.

9. The method according to claim 8, characterized in that The first pickling process includes at least one of the following features: Feature 1: the first acid includes sulfuric acid; Feature 2: The mass ratio of the non-magnetic material to the first acid is 1:2-1:5, and the concentration of the first acid is 150g / L-400g / L; Feature 3: The amount of the first oxidant is 0.5 to 3 times the molar amount of the metal contained in the non-magnetic material; Feature 4: The first oxidant includes at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate; Feature 5: The pressure of the first acid leaching is 0.4MPa-1.5MPa; Feature 6: The first acid leaching time is 20min-120min.

10. The method according to any one of claims 1 to 7, characterized in that: The second roasting includes at least one of the following characteristics: Feature 1: The second roasting is carried out under oxygen conditions; Feature 2: The temperature of the second calcination is 300℃-550℃; Feature 3: The second roasting time is 30min-180min.

11. The method according to any one of claims 1 to 10, characterized in that: Flotation is carried out in a flotation column.

12. The method according to any one of claims 1 to 11, characterized in that: The floated graphite is repaired to obtain battery-grade graphite.

13. The method according to claim 12, characterized in that The repair process includes: coating the graphite with a carbonaceous substance and then carbonizing it at a high temperature.

14. The method according to claim 13, characterized in that The carbon-containing material includes at least one of asphalt, glucose and sucrose.

15. The method according to claim 13 or 14, characterized in that The amount of the carbon-containing material is 2wt%-15wt% of the graphite.

16. The method according to any one of claims 13 to 15, characterized in that: The temperature of high temperature carbonization is 800° C.-1500° C., and / or the time of high temperature carbonization is 30 min-240 min; and / or the high temperature carbonization is performed in an oxygen-free atmosphere.

17. The method according to any one of claims 12 to 16, characterized in that: Before repairing, the graphite is purified.

18. The method according to claim 17, characterized in that Reagents used for purification include hydrochloric acid and nitric acid.

19. The method according to any one of claims 1 to 18, characterized in that: The lithium extraction liquid obtained by the lithium extraction process is subjected to lithium precipitation treatment to obtain a lithium-containing product.

20. The method according to any one of claims 1 to 19, characterized in that: The magnetic material obtained by magnetic separation is subjected to a second acid leaching, solid-liquid separation, and a second acid leaching liquid is obtained; the second acid leaching liquid is extracted and impurities are removed to obtain a first product containing nickel sulfate, cobalt sulfate and manganese sulfate.

21. The method according to claim 20, characterized in that The second acid leaching comprises: leaching the magnetic material with a second acid and a second oxidant at normal pressure.

22. The method according to claim 21, characterized in that The second pickling process includes at least one of the following features: Feature 1: the second acid includes sulfuric acid; Feature 2: The mass ratio of the magnetic material to the second acid is 1:2-1:5, and the concentration of the second acid is 150g / L-400g / L; Feature 3: The amount of the second oxidant is 0.5 to 3 times the molar amount of the metal contained in the magnetic material; Feature 4: The second oxidant includes at least one of hydrogen peroxide, sodium sulfite and sodium thiosulfate; Feature 5: The second acid leaching time is 30min-240min.

23. The method according to any one of claims 20 to 22, characterized in that: The extraction reagent used in the extraction of the second acid leaching solution includes at least one of 2-ethylhexyl phosphate mono-2-ethylhexyl ester, di(2-ethylhexyl) phosphate and di(2,4,4-trimethylpentyl)phosphinic acid.

24. The method according to any one of claims 1 to 23, characterized in that The first acid leaching liquid obtained after the first acid leaching is subjected to impurity removal and extraction to obtain a second product containing nickel sulfate, cobalt sulfate and manganese sulfate.

25. The method according to claim 24, characterized in that The extraction reagent used in the extraction of the first acid leaching solution includes at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2-ethylhexyl) phosphate and di(2,4,4-trimethylpentyl)phosphinic acid.

Images