Method and device for comprehensive recovery of waste lithium-ion batteries by metallurgy

Abstract

The present invention provides a method and device for comprehensive recovery of waste lithium-ion batteries by metallurgy. The method comprises: S1, battery pyrometallurgical pretreatment; S2, ore washing and classification of the pretreatment product to obtain coarse-grained particles, medium-fine-grained particles, fine-grained particles and the first part of lithium-containing solution; S3, magnetic separation of each particle, the magnetic separation concentrate obtained is a nickel-cobalt-manganese intermediate product, the magnetic separation tailings of coarse and medium-fine-grained particles are copper-aluminum products, and the magnetic separation tailings of fine-grained particles are graphite and black powder products; the graphite and black powder products are slurryed and graphite floated to obtain graphite products and black powder; S4, the nickel-cobalt-manganese intermediate product and the black powder are reduced and roasted to obtain roasted slag; lithium is extracted from the roasted slag to obtain the second part of lithium-containing solution and water-leached slag; S5, the first and second parts of lithium-containing solutions are combined to prepare lithium products; S6, acid leaching and impurity removal of water-leached slag. The present invention can effectively recover lithium elements and other metals and graphite in waste lithium-ion batteries.

Description

Technical Field

[0001] The present invention relates to the recycling of waste lithium-ion battery resources, and in particular to a method and device for the comprehensive recycling of waste lithium-ion batteries by beneficiation and smelting. Background Art

[0002] With the advent of the lithium-ion battery scrap tide, a large number of recycling processes have been developed and applied. At present, the main problems with the recycling process of waste lithium-ion batteries are: 1. Most of the processes focus on the recovery of nickel and cobalt, which are high in content and market price in waste lithium-ion batteries, and pay less attention to the recovery of lithium, which has a low content. Therefore, in most recycling processes, the recovery rate of nickel, cobalt and manganese is high, and the recovery rate of lithium is low. 2. At present, the definition of solid waste generated in the field of battery recycling is still incomplete, and the treatment process of a large number of fluorine-containing and phosphorus-containing diaphragm plastic parts is still imperfect. However, with the maturity of the recycling industry, a large amount of solid waste must be harmlessly treated.

[0003] CN 109935922A discloses a method for recovering valuable metals from waste lithium-ion battery positive electrode materials, using a mixture of low-valent sulfates such as sulfur and sulfide as a reducing agent to reduce high-valent compounds in the positive electrode material, then using water or weak acid to leach the reduced roasted slag, recovering lithium from the leaching solution, and recovering nickel and cobalt after acid leaching of the leached slag. The core of this method is to use low-valent sulfides as reducing agents for reduction roasting, and preferentially extract lithium after reduction to improve the recovery rate of lithium, but whether it is sulfur or sulfide, it is difficult to control the degree of reduction during reduction roasting, and it is easy to have over-sulfurization, so that nickel and cobalt are roasted into low-valent sulfates, thereby increasing the difficulty of separating lithium from nickel and cobalt.

[0004] CN 108264068A discloses a method for treating waste lithium-ion power battery positive electrode materials by electrochemical method. The reaction is carried out in an electrolysis device using sulfate and / or bisulfate as solution electrolyte. The essence of the reaction is to use the acidic solution decomposed by electrolysis of water to leach lithium in the positive electrode material. The method is novel and preferentially recovers lithium in the positive electrode material, which can improve the recovery rate of lithium. However, the reaction process is subject to the electrolysis efficiency of water, and the liquid-to-solid ratio of the electrolysis process is large, so the efficiency is low.

[0005] CN 108767354A discloses a method for treating waste lithium-ion battery positive electrode materials using an ammonium salt roasting process. After the ammonium salt is roasted, water immersion is adopted, and valuable metals Ni, Co, Mn, and Li are all transferred to a solution, and then recovered from the solution. The process recycles the ammonium salt and can reduce production costs, but still has the disadvantages of a long recovery process, lithium dispersion, and a low recovery rate.

[0006] CN 106505270A also discloses a process for treating waste ternary lithium-ion battery positive electrode materials by ammonium salt roasting. After the aluminum foil is removed from the roasting slag after ammonium salt roasting, acid leaching is used to dissolve cobalt and lithium, and then the cobalt is precipitated in the form of cobalt hydroxide by precipitation, and finally lithium is recovered. This method avoids the extraction process and can effectively reduce the loss of lithium, but the method has limited applicability to waste lithium-ion batteries with complex composition and scattered and difficult-to-separate models.

[0007] It can be seen that the existing technology has the problem of low recovery rate when recycling lithium elements in waste lithium-ion batteries. In addition, there is currently a lack of comprehensive methods for recycling lithium, nickel, cobalt, manganese, copper, aluminum and other metals and graphite in waste lithium-ion batteries, and the treatment of phosphorus-containing and fluorine-containing diaphragms and plastic parts in batteries is not effective enough. Summary of the invention

[0008] The main purpose of the present invention is to provide a method and device for the comprehensive recovery of waste lithium-ion batteries by metallurgy and smelting, so as to improve the recovery rate of lithium elements in waste lithium-ion batteries, and at the same time comprehensively recover various metals such as lithium, nickel, cobalt, manganese, copper, aluminum, and graphite in waste lithium-ion batteries, and effectively treat phosphorus-containing and fluorine-containing diaphragms and plastic parts in batteries.

[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for the comprehensive recovery of waste lithium-ion batteries by metallurgy is provided, which comprises the following steps: S1, performing pyrometallurgical pretreatment on the waste lithium-ion batteries to obtain a pretreatment product; S2, performing ore washing and classification treatment on the pretreatment product to obtain coarse-grained particles, medium-fine-grained particles, fine-grained particles and a first part of lithium-containing solution, wherein the particle size of the coarse-grained particles is larger than that of the medium-fine-grained particles, and the particle size of the medium-fine-grained particles is larger than that of the fine-grained particles; S3, performing magnetic separation on the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles respectively, and the obtained magnetic separation concentrate is used as The intermediate product of nickel, cobalt and manganese, the magnetic tailings of coarse-grained particles and medium-fine-grained particles are used as copper and aluminum products, and the magnetic tailings of fine-grained particles are graphite and black powder products; the graphite and black powder products are sequentially subjected to slurry mixing and graphite flotation to obtain graphite products and black powder; S4, the nickel, cobalt and manganese intermediate product and black powder are reduction roasted to obtain roasted slag; the roasted slag is subjected to water leaching for lithium extraction to obtain the second part of lithium-containing solution and water-leached slag; S5, the first part of the lithium-containing solution and the second part of the lithium-containing solution are combined to obtain a combined solution; the lithium product is prepared by using the combined solution; S6, the water-leached slag is acid-leached and impurity-removed to obtain a solution product containing nickel, cobalt and manganese.

[0010] Further, in step S1, the pyrometallurgical pretreatment process includes: dismantling and crushing the waste lithium-ion batteries to obtain crushed materials; preferably, the particle size of the crushed materials is below 50 mm; the crushed materials are subjected to low-temperature pyrolysis under a protective atmosphere and a temperature of 400 to 700° C. to obtain a pretreated product; preferably, the temperature of the low-temperature pyrolysis is 600 to 650° C., more preferably 610 to 640° C.; preferably, the time of the low-temperature pyrolysis is 0.5 to 6 hours; preferably, before the step of dismantling and crushing the waste lithium-ion batteries, step S1 also includes the step of discharging the waste lithium-ion batteries.

[0011] Furthermore, in step S2, the particle size of the coarse-grained particles is greater than 2 mm, the particle size of the fine-grained particles is less than 0.2 mm, and the particle size of the medium-fine-grained particles is between the particle sizes of the coarse-grained particles and the fine-grained particles; preferably, in step S3, the magnetic field strength for magnetic separation of the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles is 40 to 280 kA / m, respectively.

[0012] Furthermore, the steps of sequentially slurrying the graphite and black powder products and flotation of graphite include: mixing the graphite and black powder products with water into a flotation slurry with a concentration of 5 to 35 wt%; adding a regulator, a graphite collector and a frother to the flotation slurry to flotation graphite to obtain a graphite product and black powder.

[0013] Furthermore, in step S4, the reducing agent used in the reduction roasting process is the graphite product obtained in step S3, or the reduction roasting process is carried out under a reducing atmosphere; preferably, the reducing atmosphere is composed of a reducing gas and an optional inert gas, the reducing gas is one or more of hydrogen, ammonia, methane and sulfur dioxide, and the inert gas is nitrogen and / or argon; preferably, the temperature of the reduction roasting process is 400-700°C, and the reaction time is 0.5-6h.

[0014] Furthermore, in step S5, the lithium in the combined solution is evaporated and crystallized in the form of lithium hydroxide, or carbon dioxide is introduced into the combined solution or a soluble carbonate is added to precipitate the lithium in the form of lithium carbonate to obtain a lithium product; preferably, before the step of preparing the lithium product using the combined solution, step S5 also includes the step of removing impurity ions in the combined solution using chemical precipitation or ion exchange resin.

[0015] Further, in step S6, the water leaching residue is acid-leached to obtain an acid leaching solution; the impurity removal step includes: adjusting the pH value of the acid leaching solution to above 4.2, removing iron impurities and aluminum impurities, and obtaining an iron-removing aluminum solution; adding fluoride to the iron-removing aluminum solution to remove magnesium impurities and obtain a magnesium-removing solution; preferably, the fluoride is sodium fluoride; adding sulfide salt and / or hydrogen sulfide to the magnesium-removing solution to remove copper impurities and zinc impurities to obtain a solution product containing nickel, cobalt and manganese; preferably, the sulfide salt is sodium sulfide; or, the impurity removal step includes: extracting the acid leaching solution with an extractant to obtain a solution product containing nickel, cobalt and manganese; preferably, the extractant is P204 extractant.

[0016] Furthermore, before the step of acid leaching the water-leached slag, step S6 also includes the step of reduction smelting the water-leached slag; preferably, the water-leached slag is reduction smelted at a temperature of 1200-1600° C. for 0.5-5 h to obtain a nickel-cobalt-manganese alloy, and then the nickel-cobalt-manganese alloy is acid leached and impurities are removed in sequence to obtain a solution product containing nickel, cobalt and manganese.

[0017] Furthermore, a first flue gas is obtained in the pyrometallurgical pretreatment step, and a second flue gas is obtained in the reduction smelting step. The recovery method also includes the steps of performing secondary combustion, surface cooling, dust removal, and tail gas purification on the first flue gas and the second flue gas in sequence.

[0018] Furthermore, the waste lithium-ion batteries are one or more of waste lithium cobalt oxide batteries, lithium manganese oxide batteries, nickel-manganese binary composite lithium-ion batteries, nickel-cobalt binary composite lithium-ion batteries, cobalt-manganese binary composite lithium-ion batteries, nickel-cobalt-manganese ternary composite lithium-ion batteries, and nickel-cobalt-aluminum ternary composite lithium-ion batteries.

[0019] According to another aspect of the present invention, a comprehensive recovery device for the selection and smelting of waste lithium-ion batteries is provided, which comprises: a pyrometallurgical pretreatment unit having a waste lithium-ion battery inlet and a pretreatment product outlet, the pyrometallurgical pretreatment unit being used to perform pyrometallurgical pretreatment on the waste lithium-ion batteries to obtain a pretreatment product; a washing and grading unit having a pretreatment product inlet and a first water inlet, the pretreatment product inlet being connected to the pretreatment product inlet, the washing and grading unit being used to perform washing and grading on the pretreatment product to obtain coarse-grained particles, medium-fine-grained particles, fine-grained particles and a first water inlet. Part of the solution contains lithium, and the particle size of the coarse-grade particles is larger than that of the medium-fine-grade particles, and the particle size of the medium-fine-grade particles is larger than that of the fine-grade particles; a magnetic separation unit is connected to the outlet of the ore washing and grading unit, and the magnetic separation unit is used to magnetically separate the coarse-grade particles, the medium-fine-grade particles and the fine-grade particles to obtain nickel-cobalt-manganese intermediate products, coarse-grade particle magnetic separation tailings, medium-fine-grade particle magnetic separation tailings and fine-grade particle magnetic separation tailings, the coarse-grade particle magnetic separation tailings and the medium-fine-grade particle magnetic separation tailings are used as copper and aluminum products, and the fine-grade particle magnetic separation tailings are graphite and black powder products; graphite recovery The graphite recovery unit includes a slurry mixing unit and a flotation unit connected in sequence, the slurry mixing unit is used to mix the graphite and black powder products, and the flotation unit is used to flotate the graphite to obtain graphite products and black powder; the reduction roasting unit is connected to the outlet of the magnetic separation unit and the outlet of the flotation unit, respectively, and the reduction roasting unit is used to reduce and roast the nickel-cobalt-manganese intermediate product and the black powder to obtain roasted slag; the water immersion unit has a roasted slag inlet and a second water inlet, the roasted slag inlet is connected to the outlet of the reduction roasting unit, and the water immersion unit is used to water the roasted slag Lithium is leached to obtain a second lithium-containing solution and water-leached slag; a lithium recovery unit, whose inlet is connected to the outlet of the water-leaching unit and the outlet of the ore washing and grading unit respectively, and the lithium recovery unit is used to prepare a lithium product by using a combined solution of the first lithium-containing solution and the second lithium-containing solution; an acid leaching unit, having a water-leaching slag inlet, an acid inlet and an acid leaching liquid outlet, the water-leaching slag inlet is connected to the outlet of the water-leaching unit, and the acid leaching unit is used to acid-leach the water-leaching slag to obtain an acid leaching liquid; an impurity removal unit, connected to the acid leaching liquid outlet, and the impurity removal unit is used to remove impurities from the acid leaching liquid to obtain a solution product containing nickel, cobalt and manganese.

[0020] Furthermore, the pyrometallurgical pretreatment unit includes: a disassembly and crushing unit having a waste lithium-ion battery inlet and a crushed material outlet; a low-temperature pyrolysis unit having a crushed material inlet, an inert gas inlet and a pretreatment product outlet, and the crushed material inlet is connected to the crushed material outlet.

[0021] Furthermore, the pyrometallurgical pretreatment unit also includes a discharge unit, which is located upstream of the disassembly and crushing unit and connected to the inlet of the waste lithium-ion batteries. The discharge unit is used to discharge the waste lithium-ion batteries.

[0022] Furthermore, the graphite recovery unit also includes: a regulator supply unit connected to the flotation unit for supplying regulator thereto; a graphite collector supply unit connected to the flotation unit for supplying graphite collector thereto; and a frother supply unit connected to the flotation unit for supplying frother thereto.

[0023] Furthermore, the reduction roasting unit also has a first reducing agent inlet, which is connected to the outlet of the flotation unit and is used to use the graphite product obtained in the graphite flotation process as a reducing agent in the reduction roasting process; or, the reduction roasting unit also has a reducing gas inlet, and the recovery device also includes a reducing gas supply unit, which is connected to the reducing gas inlet.

[0024] Furthermore, the recovery device also includes an inert gas supply unit, which is respectively connected to the reducing gas inlet and the inert gas inlet of the low-temperature pyrolysis unit.

[0025] Furthermore, the lithium recovery unit includes: an impurity removal agent supply unit for supplying an impurity removal agent; an impurity removal and purification unit, whose inlet is respectively connected to the outlet of the water immersion unit, the outlet of the ore washing and grading unit and the impurity removal agent supply unit, and the impurity removal and purification unit is used to subject the combined solution of the first part of the lithium-containing solution and the second part of the lithium-containing solution to an impurity removal reaction to obtain an impurity-removed lithium solution; a lithium product preparation unit, which is connected to the outlet of the impurity removal and purification unit, and the lithium product preparation unit is used to evaporate and crystallize the impurity-removed lithium solution or precipitate lithium carbonate to obtain a lithium product.

[0026] Further, the impurity removal unit includes: a pH adjustment unit connected to the outlet of the acid leaching solution, the pH adjustment unit is used to adjust the pH value of the acid leaching solution to above 4.2 to obtain an iron-aluminum removal solution; a magnesium removal unit, having a fluoride inlet and an iron-aluminum removal solution inlet, the iron-aluminum removal solution inlet is connected to the outlet of the pH adjustment unit, and the magnesium removal unit is used to remove magnesium impurities in the iron-aluminum removal solution to obtain a magnesium removal solution; a copper-zinc removal unit, having a magnesium removal solution inlet and a sulfide inlet, the magnesium removal solution inlet is connected to the outlet of the magnesium removal unit, the sulfide inlet is used to introduce sulfide salts and / or hydrogen sulfide, and the copper-zinc removal unit is used to remove copper impurities and zinc impurities in the magnesium solution to obtain a solution product containing nickel, cobalt and manganese; or, the impurity removal unit is an extraction impurity removal unit.

[0027] Furthermore, the recovery device also includes a reduction smelting unit, which is arranged on a flow path connecting the water leaching slag inlet and the water leaching unit, and the reduction smelting unit also has a flux inlet, the reduction smelting unit is used to perform reduction smelting on the water leaching slag to obtain the nickel-cobalt-manganese alloy, and the acid leaching unit is used to perform acid leaching on the nickel-cobalt-manganese alloy to obtain the acid leaching solution.

[0028] Furthermore, the pyrometallurgical pretreatment unit also has a first flue gas outlet, the reduction smelting unit also has a second flue gas outlet, and the recovery device also includes a flue gas treatment unit, which is respectively connected to the first flue gas outlet and the second flue gas outlet.

[0029] The present invention provides a method for the comprehensive recovery of waste lithium-ion batteries by combined selection and smelting, which can more effectively recover the lithium element in waste lithium-ion batteries in a shorter process, and can comprehensively recover the lithium, nickel, cobalt, manganese, copper, aluminum and other metals, as well as graphite therein, and effectively remove the phosphorus- and fluorine-containing diaphragms and plastic parts in the batteries by pyrometallurgy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 A flow chart showing a method for comprehensive recovery of waste lithium-ion batteries by metallurgy and separation according to an embodiment of the present invention; and

[0032] Figure 2 A structural block diagram of a device for the integrated recovery of waste lithium-ion batteries by metallurgy is shown according to an embodiment of the present invention.

[0033] The above drawings include the following reference numerals:

[0034] 10. Fire pretreatment unit; 11. Disassembly and crushing unit; 12. Low-temperature pyrolysis unit; 13. Discharge unit; 20. Ore washing and classification unit; 30. Magnetic separation unit; 40. Graphite recovery unit; 41. Slurry adjustment unit; 42. Flotation unit; 43. Adjuster supply unit; 44. Graphite collector supply unit; 45. Frothing agent supply unit; 50. Reduction roasting unit; 60. Water leaching unit; 70. Lithium recovery unit; 71. Impurity removal agent supply unit; 72. Impurity removal and purification unit; 73. Lithium product preparation unit; 80. Acid leaching unit; 90. Impurity removal unit; 91. pH adjustment unit; 92. Magnesium removal unit; 93. Copper and zinc removal unit; 100. Inert gas supply unit; 110. Reduction smelting unit; 120. Flue gas treatment unit. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] As described in the background technology section, the prior art has the problem of low recovery rate when recycling lithium elements in waste lithium-ion batteries. In addition, there is currently a lack of comprehensive methods for recycling lithium, nickel, cobalt, manganese, copper, aluminum and other metals, as well as graphite in waste lithium-ion batteries, and the treatment of phosphorus-containing and fluorine-containing diaphragms and plastic parts in batteries is not effective enough.

[0037] In order to solve the above problems, the present invention provides a comprehensive recovery method of waste lithium-ion batteries by metallurgy. Figure 1 As shown, the recycling method comprises the following steps: S1, performing pyrometallurgical pretreatment on waste lithium-ion batteries to obtain pretreatment products; S2, washing and classifying the pretreatment products to obtain coarse-grained particles, medium-fine-grained particles, fine-grained particles and the first part of lithium-containing solution, wherein the particle size of the coarse-grained particles is larger than that of the medium-fine-grained particles, and the particle size of the medium-fine-grained particles is larger than that of the fine-grained particles; S3, magnetically separating the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles respectively, and obtaining the magnetically separated concentrate as the nickel-cobalt-manganese intermediate product, and the coarse-grained particles and the medium-fine-grained particles are separated. The magnetic tailings of the particles are used as copper and aluminum products, and the magnetic tailings of the fine-grained particles are graphite and black powder products; the graphite and black powder products are sequentially subjected to slurry mixing and graphite flotation to obtain graphite products and black powder; S4, the nickel, cobalt and manganese intermediate products and the black powder are reduction roasted to obtain roasted slag; the roasted slag is subjected to water leaching for lithium extraction to obtain the second part of lithium-containing solution and water-leached slag; S5, the first part of the lithium-containing solution and the second part of the lithium-containing solution are combined to obtain a combined solution; the combined solution is used to prepare a lithium product; S6, the water-leached slag is acid-leached and impurity-removed to obtain a solution product containing nickel, cobalt and manganese.

[0038] The above process is used to treat waste lithium-ion batteries. The plastic shell and phosphorus- and fluorine-containing diaphragms in waste lithium-ion batteries can be effectively decomposed through pyrometallurgical pretreatment, and nickel, cobalt and manganese can be converted from non-magnetic to magnetic. The lithium-ion battery materials after pyrometallurgical pretreatment mainly include nickel, cobalt and manganese, copper, aluminum, iron, and black powder (black powder includes the original negative electrode material graphite of the battery, the carbon produced during the pyrometallurgical pretreatment, and a part of lithium). The pretreatment products are divided into coarse-grained particles, medium-fine-grained particles, and fine-grained particles through ore washing and classification, and a part of the soluble lithium salts can enter the water to form the first part of the lithium-containing solution. Since the black powder has a small particle size, it is mainly enriched in the fine-grained particles, and the particle size of the remaining components is large, and they are enriched in the coarse-grained particles and the medium-fine-grained particles. By magnetic separation, the magnetic nickel, cobalt and manganese in each particle size can be separated, and a part of lithium element will be entrained therein to obtain a nickel, cobalt and manganese intermediate product. The magnetic tailings of coarse particles and medium and fine particles are mainly composed of copper and aluminum, which can be used as copper and aluminum products, while the magnetic tailings of fine particles are graphite and black powder products. After the graphite and black powder products are successively subjected to slurry mixing and graphite flotation, the graphite can be enriched to obtain a graphite product, and the flotation tailings are black powder. Secondly, the present invention performs reduction roasting on the nickel, cobalt and manganese intermediate product and black powder, and then performs water leaching to extract lithium. Due to the different reducibility of lithium, nickel, cobalt and manganese, lithium can be preferably extracted by reduction roasting-water leaching, so that lithium is enriched to form a second part of lithium-containing solution. After combining the first part of the lithium-containing solution and the second part of the lithium-containing solution, lithium can be extracted by chemical precipitation, evaporation crystallization and other methods to form a lithium product. The remaining water leaching residue after water leaching can be acid leached and impurity removed to obtain a solution product containing nickel, cobalt and manganese.

[0039] From the perspective of lithium recovery process, the traditional waste lithium-ion battery is a process of first recovering nickel, cobalt and manganese and then recovering lithium, which results in serious lithium loss (lithium recovery rate <90% or even lower), long extraction and separation process flow, and large material flux. However, according to the different reducibility of lithium, nickel, cobalt and manganese, the present invention adopts reduction roasting-leaching to preferentially extract lithium, which can effectively improve the recovery rate of lithium in waste batteries (>98%), reduce the extraction flux, and has obvious process advantages. From the overall perspective, the present invention adopts a combined process of mineral processing-metallurgy to comprehensively recover lithium, nickel, cobalt, manganese, copper, aluminum and other metals and graphite in waste lithium-ion batteries. Due to the characteristics of the mineral processing process itself, the mineral processing process is used to separate the valuable components in waste batteries, with low comprehensive cost and significant separation effect. In addition, for the plastic shell and phosphorus-containing and fluorine-containing diaphragm in the battery, the present invention can also decompose them through pyrometallurgical pretreatment, and the obtained flue gas can be post-processed.

[0040] In a preferred embodiment, in step S1, the pyrometallurgical pretreatment process includes: dismantling and crushing the waste lithium-ion battery to obtain crushed material; preferably, the particle size of the crushed material is less than 50 mm; the crushed material is subjected to low-temperature pyrolysis under a protective atmosphere and a temperature of 400 to 700°C to obtain a pretreated product; preferably, the temperature of the low-temperature pyrolysis is 600 to 650°C, more preferably 610 to 640°C; preferably, the time of the low-temperature pyrolysis is 0.5 to 6 hours. The above process can improve the pyrolysis effect of the plastic shell and the phosphorus-containing and fluorine-containing diaphragm on the one hand, and can more fully convert nickel, cobalt and manganese into magnetism on the other hand, so that it can be more effectively separated in the subsequent magnetic separation process. The specific method of dismantling and crushing can be the common method in the art. Preferably, nitrogen is introduced as a protective gas during the dismantling and crushing process to prevent the battery cell from catching fire during the crushing process; the exhaust gas generated during the crushing process can be treated by the exhaust gas purification system, and the exhaust gas is discharged after reaching the standard.

[0041] Preferably, before the step of dismantling and crushing the waste lithium-ion batteries, step S1 also includes a step of discharging the waste lithium-ion batteries. When the batteries are scrapped, the residual electricity has the risk of explosion during storage and crushing. The discharge step can reduce the explosion risk and avoid problems such as fire caused by the residual electricity during the dismantling and crushing process.

[0042] In a preferred embodiment, in step S2, the particle size of the coarse-grained particles is greater than 2 mm, the particle size of the fine-grained particles is less than 0.2 mm, and the particle size of the medium-fine-grained particles is between the particle sizes of the coarse-grained particles and the fine-grained particles. Controlling the size of each level of particles within the above range is more conducive to separating the black powder and metal components (copper, aluminum, nickel, cobalt, manganese, etc.), graphite will be in the fine-grained particles as much as possible, and copper, aluminum, nickel, cobalt, manganese, etc. will be enriched in the coarse-grained particles and the medium-fine-grained particles.

[0043] In order to more fully remove magnetic impurities such as nickel, cobalt and manganese, in a preferred embodiment, in step S3, the magnetic field strength of the magnetic separation for coarse particles, medium-fine particles and fine particles is 40-280 kA / m respectively.

[0044] In order to further improve the recovery effect of graphite, in a preferred embodiment, the steps of sequentially slurrying and graphite flotation of graphite and black powder products include: mixing the graphite and black powder products with water into a flotation pulp with a concentration of 5 to 35wt%; sequentially adding a regulator, a graphite collector and a foaming agent to the flotation pulp to perform graphite flotation to obtain a graphite product and black powder. Preferably, the graphite collector is a hydrocarbon oil collector, and the hydrocarbon oil collector is kerosene and / or diesel; preferably, the foaming agent is pine oil and / or methyl isobutyl carbinol; preferably, the regulator is one or more of sodium hydrosulfide, sodium sulfide, and ammonium sulfide. The above reagents are used to achieve a better recovery effect of graphite.

[0045] Preferably, in step S4, the reducing agent used in the reduction roasting process is the graphite product obtained in step S3, which is conducive to full utilization of resources. Alternatively, the reduction roasting process is carried out in a reducing atmosphere. Preferably, the reducing atmosphere is composed of a reducing gas and an optional inert gas, the reducing gas is one or more of hydrogen, ammonia, methane and sulfur dioxide, and the inert gas is nitrogen and / or argon; preferably, the temperature of the reduction roasting process is 400-700°C, and the reaction time is 0.5-6h.

[0046] In a preferred embodiment, in step S5, the lithium in the combined solution is recovered in the form of lithium hydroxide or lithium carbonate to obtain a lithium product; in the specific operation process, carbon dioxide or a soluble carbonate (such as sodium carbonate, etc.) can be introduced into the combined solution to precipitate the lithium element in the form of lithium carbonate. Alternatively, the lithium hydroxide product can be prepared by evaporation and crystallization, which has a higher lithium recovery rate and higher processing efficiency.

[0047] In addition, in order to obtain a relatively pure lithium product, the impurity content (Al, Cu, F, P, etc.) in the combined solution can be analyzed first. If the impurity content is qualified, lithium hydroxide or lithium carbonate products are prepared from the leachate. If the impurity content is unqualified, lithium hydroxide or lithium carbonate products are prepared after a purification process. The purification process can be a chemical precipitation method or an ion exchange resin method for removing impurities.

[0048] In a preferred embodiment, in step S6, the water leaching residue is acid-leached to obtain an acid leaching solution; the impurity removal step comprises: adjusting the pH value of the acid leaching solution to above 4.2 to remove iron impurities and aluminum impurities to obtain an iron-removing aluminum solution; adding fluoride to the iron-removing aluminum solution to remove magnesium impurities to obtain a magnesium-removing solution; preferably, the fluoride is sodium fluoride; adding sulfide salt and / or hydrogen sulfide to the magnesium-removing solution to remove copper impurities and zinc impurities to obtain a solution product containing nickel, cobalt and manganese; preferably, the sulfide salt is sodium sulfide; or, the impurity removal step comprises: extracting the acid leaching solution with an extractant to obtain a solution product containing nickel, cobalt and manganese; preferably, the extractant is a P204 extractant.

[0049] In a preferred embodiment, before the step of acid leaching the water-leached slag, step S6 also includes the step of reduction smelting the water-leached slag. In this way, the reduction smelting process can more fully reduce and enrich the nickel, cobalt and manganese in the water-leached slag, and the reduction smelting process also solves the problems of fluorine dispersion and difficulty in opening the circuit that plague the power battery recovery process, and can obtain smelting slag containing F, realize partial opening of the F element, and take into account the disposal of harmful substances while recycling resources. Preferably, the first flue gas generated in the above-mentioned pyrometallurgical pretreatment process can be post-treated to obtain fluorine-containing gypsum slag, which can be sent to the reduction smelting process for synergistic treatment, which is more conducive to improving the environmental protection of the process. Preferably, the water-leached slag is reduced and smelted at a temperature of 1200-1600°C for 0.5-5h to obtain a nickel-cobalt-manganese alloy, and then the nickel-cobalt-manganese alloy is acid leached and impurities are removed in turn to obtain a solution product containing nickel, cobalt and manganese.

[0050] In the actual reduction smelting process, the water-leached slag, flux and reducing agent are mixed and then reduced in a smelting furnace. The specific flux is preferably quartz sand, limestone, dolomite, calcite, etc., and the specific reducing agent is preferably coal, coke, petroleum coke, activated carbon, etc. The specific amount of each reagent can be adjusted according to the actual situation such as the amount of water-leached slag, and will not be repeated here.

[0051] In a preferred embodiment, the first flue gas is obtained in the pyrometallurgical pretreatment step, and the second flue gas is obtained in the reduction smelting step. The recovery method further includes the steps of secondary combustion, surface cooling, dust removal, and tail gas purification for the first flue gas and the second flue gas in sequence, and the tail gas can be discharged after the tail gas is purified to meet the standards. The dust removal process can use a high-temperature bag filter, and the specific tail gas purification step can use one or more combinations of common waste gas treatment devices such as an alkali absorption device, an activated carbon device, a UV photolysis device, and a biological filtration purification device.

[0052] Preferably, after obtaining the solution product containing nickel, cobalt and manganese, the nickel, cobalt and manganese elements can be further separated by wet treatment.

[0053] The above-mentioned waste lithium-ion batteries refer to waste lithium-ion batteries obtained after safe discharge, and / or waste products generated during the production process of lithium-ion batteries. In a preferred embodiment, the waste lithium-ion batteries are one or more of waste lithium cobalt oxide batteries, lithium manganese oxide batteries, nickel-manganese binary composite lithium-ion batteries, nickel-cobalt binary composite lithium-ion batteries, cobalt-manganese binary composite lithium-ion batteries, nickel-cobalt-manganese ternary composite lithium-ion batteries, and nickel-cobalt-aluminum ternary composite lithium-ion batteries.

[0054] According to another aspect of the present invention, a comprehensive recovery device for waste lithium-ion batteries is provided. Figure 2As shown, the recovery device includes a pyrometallurgical pretreatment unit 10, a ore washing and classification unit 20, a magnetic separation unit 30, a graphite recovery unit 40, a reduction roasting unit 50, a water leaching unit 60, a lithium recovery unit 70, an acid leaching unit 80, and an impurity removal unit 90. The pyrometallurgical pretreatment unit 10 has a waste lithium ion battery inlet and a pretreatment product outlet. The pyrometallurgical pretreatment unit 10 is used to perform pyrometallurgical pretreatment on the waste lithium ion battery to obtain a pretreatment product; the ore washing and classification unit 20 has a pretreatment product inlet and a first water inlet, the pretreatment product inlet is connected to the pretreatment product inlet, and the ore washing and classification unit 20 is used to perform ore washing and classification on the pretreatment product to obtain a coarse particle size particle. The coarse-grained particles A, medium-fine-grained particles B, fine-grained particles C and the first part of the lithium-containing solution D, and the particle size of the coarse-grained particles A is larger than the particle size of the medium-fine-grained particles B, and the particle size of the medium-fine-grained particles B is larger than the particle size of the fine-grained particles C; the magnetic separation unit 30 is connected to the outlet of the ore washing and classification unit 20, and the magnetic separation unit 30 is used to magnetically separate the coarse-grained particles A, the medium-fine-grained particles B and the fine-grained particles C to obtain the nickel-cobalt-manganese intermediate product G, the coarse-grained particles magnetic separation tailings, the medium-fine-grained particles magnetic separation tailings and the fine-grained particles magnetic separation tailings, the coarse-grained particles magnetic separation tailings and the medium-fine-grained particles magnetic separation tailings are used as the copper-aluminum product E, and the fine-grained particles magnetic separation tailings are the graphite and black powder product F. The graphite recovery unit 40 is connected to the outlet of the magnetic separation unit 30, and the graphite recovery unit 40 includes a slurry mixing unit 41 and a flotation unit 42 connected in sequence, the slurry mixing unit 41 is used to mix the graphite and the black powder product F, and the flotation unit 42 is used to flotate the graphite to obtain the graphite product H and the black powder J; the reduction roasting unit 50 is connected to the outlet of the magnetic separation unit 30 and the outlet of the flotation unit 42 respectively, and the reduction roasting unit 50 is used to reduce and roast the nickel-cobalt-manganese intermediate product G and the black powder J to obtain roasted slag; the water immersion unit 60 has a roasted slag inlet and a second water inlet, and the roasted slag inlet is connected to the outlet of the reduction roasting unit 50, and the water immersion unit 60 is used to The slag is subjected to water leaching for lithium extraction to obtain a second lithium-containing solution K and a water-leached slag L; the inlet of a lithium recovery unit 70 is connected to the outlet of the water leaching unit 60 and the outlet of the washing and grading unit 20 respectively, and the lithium recovery unit 70 is used to recover lithium from the combined solution of the first lithium-containing solution D and the second lithium-containing solution K to obtain a lithium product M; the acid leaching unit 80 has a water leaching slag inlet, an acid inlet and an acid leaching liquid outlet, the water leaching slag inlet is connected to the outlet of the water leaching unit 60, and the acid leaching unit 80 is used to acid-leach the water leaching slag to obtain an acid leaching liquid; the impurity removal unit 90 is connected to the acid leaching liquid outlet, and the impurity removal unit 90 is used to remove impurities from the acid leaching liquid to obtain a solution product N containing nickel, cobalt and manganese.

[0055] The above-mentioned device is used to treat waste lithium-ion batteries. The plastic shell and phosphorus- and fluorine-containing diaphragms in the waste lithium-ion batteries can be effectively decomposed through pyrometallurgical pretreatment, and nickel, cobalt and manganese can be converted from non-magnetic to magnetic. The lithium-ion battery materials after pyrometallurgical pretreatment mainly include nickel, cobalt and manganese, copper, aluminum, iron, and black powder (black powder includes the original negative electrode material graphite of the battery, the carbon produced during the pyrometallurgical pretreatment, and a part of lithium). The pretreatment products are divided into coarse-grained particles, medium-fine-grained particles, and fine-grained particles through ore washing and classification, and a part of the soluble lithium salts can enter the water to form the first part of the lithium-containing solution. Since the black powder has a small particle size, it is mainly enriched in the fine-grained particles, and the particle size of the remaining components is large, and they are enriched in the coarse-grained particles and the medium-fine-grained particles. By magnetic separation, the magnetic nickel, cobalt and manganese in each particle size can be separated, and a part of lithium element will be entrained therein to obtain a nickel, cobalt and manganese intermediate product. The magnetic tailings of coarse particles and medium and fine particles are mainly composed of copper and aluminum, which can be used as copper and aluminum products, while the magnetic tailings of fine particles are graphite and black powder products. After the graphite and black powder products are successively subjected to slurry mixing and graphite flotation, the graphite can be enriched to obtain a graphite product, and the flotation tailings are black powder. Secondly, the present invention performs reduction roasting on the nickel, cobalt and manganese intermediate product and black powder, and then performs water leaching to extract lithium. Due to the different reducibility of lithium, nickel, cobalt and manganese, lithium can be preferably extracted by reduction roasting-water leaching, so that lithium is enriched to form a second part of lithium-containing solution. After combining the first part of the lithium-containing solution and the second part of the lithium-containing solution, lithium can be extracted by chemical precipitation or evaporative crystallization to form a lithium product. The remaining water leaching residue after water leaching can be acid leached and impurity removed to obtain a solution product containing nickel, cobalt and manganese.

[0056] From the perspective of lithium recovery process, the traditional waste lithium-ion battery is a process of first recovering nickel, cobalt and manganese and then recovering lithium, which results in serious lithium loss (lithium recovery rate <90% or even lower), long extraction and separation process flow, and large material flux. However, according to the different reducibility of lithium, nickel, cobalt and manganese, the present invention adopts reduction roasting-leaching to preferentially extract lithium, which can effectively improve the recovery rate of lithium in waste batteries (>98%), reduce the extraction flux, and has obvious process advantages. From the overall perspective, the present invention adopts a combined process of mineral processing-metallurgy to comprehensively recover lithium, nickel, cobalt, manganese, copper, aluminum and other metals and graphite in waste lithium-ion batteries. Due to the characteristics of the mineral processing process itself, the mineral processing process is used to separate the valuable components in waste batteries, with low comprehensive cost and significant separation effect. In addition, for the plastic shell and phosphorus-containing and fluorine-containing diaphragm in the battery, the present invention can also decompose them through pyrometallurgical pretreatment, and the obtained flue gas can be post-processed.

[0057] In a preferred embodiment, the pyrometallurgical pretreatment unit 10 includes a disassembly and crushing unit 11 and a low-temperature pyrolysis unit 12. The disassembly and crushing unit 11 has an inlet for waste lithium-ion batteries and an outlet for crushed materials; the low-temperature pyrolysis unit 12 has an inlet for crushed materials, an inert gas inlet, and an outlet for pretreatment products, and the crushed material inlet is connected to the crushed material outlet. In this way, the waste lithium-ion batteries are disassembled and crushed and then subjected to low-temperature pyrolysis, so that the plastic shell and phosphorus-containing and fluorine-containing diaphragms in the battery can be removed by pyrolysis. Preferably, the low-temperature pyrolysis unit 12 is used to perform low-temperature pyrolysis of the crushed materials discharged from the disassembly and crushing unit 11 at a temperature of 400 to 700°C to obtain pretreatment products.

[0058] In a preferred embodiment, the pyrometallurgical pretreatment unit 10 further includes a discharge unit 13, which is located upstream of the dismantling and crushing unit 11 and connected to the inlet of the waste lithium-ion battery. The discharge unit 13 is used to discharge the waste lithium-ion battery. When the battery is scrapped, the residual electricity has an explosion hazard during storage and crushing. The discharge step can reduce the explosion hazard and avoid problems such as fire caused by the residual electricity during the dismantling and crushing process.

[0059] In a preferred embodiment, Figure 1 As shown, the graphite recovery unit 40 also includes a regulator supply unit 43, a graphite collector supply unit 44 and a frother supply unit 45; the regulator supply unit 43 is connected to the flotation unit 42 for supplying the graphite regulator thereto; the graphite collector supply unit 44 is connected to the flotation unit 42 for supplying the collector thereto; the frother supply unit 45 is connected to the flotation unit 42 for supplying the frother thereto. In this way, the graphite product and the black powder after slurry adjustment can be subjected to graphite flotation under the action of the graphite collector, the frother and the regulator, so as to more fully recover and separate the graphite.

[0060] In a preferred embodiment, the reduction roasting unit 50 also has a first reducing agent inlet, which is connected to the outlet of the flotation unit 42, and is used to use the graphite product obtained in the graphite flotation process as a reducing agent in the reduction roasting process; or, the reduction roasting unit 50 also has a reducing gas inlet, and the recovery device also includes a reducing gas supply unit, which is connected to the reducing gas inlet. Preferably, the recovery device also includes an inert gas supply unit 100, which is respectively connected to the reducing gas inlet and the inert gas inlet of the low-temperature pyrolysis unit 12. In this way, the inert gas can be introduced into the reduction roasting unit 50 to form a reducing atmosphere together with the first reducing gas, so that the black powder and the nickel-cobalt-manganese intermediate product are subjected to reduction roasting.

[0061] In a preferred embodiment, the lithium recovery unit 70 includes: an impurity removal agent supply unit 71 for supplying an impurity removal agent; an impurity removal purification unit 72, the inlet of which is respectively connected to the outlet of the water immersion unit 60, the outlet of the washing and grading unit 20 and the impurity removal agent supply unit 71, and the impurity removal purification unit 72 is used to make the combined solution of the first part of the lithium-containing solution and the second part of the lithium-containing solution undergo an impurity removal and purification reaction to obtain an impurity-removed lithium solution; a lithium product preparation unit 73, which is connected to the outlet of the impurity removal and purification unit 72, and the lithium product preparation unit 73 is used to evaporate and crystallize the impurity-removed lithium solution or precipitate lithium carbonate to obtain a lithium product. Preferably, the magnesium removal agent is sodium hydroxide, calcium hydroxide, and sodium fluoride, and preferably, the calcium removal agent is sodium carbonate and sodium fluoride.

[0062] In a preferred embodiment, the impurity removal unit 90 includes: a pH adjustment unit 91, which is connected to the outlet of the acid leaching solution, and the pH adjustment unit 91 is used to adjust the pH value of the acid leaching solution to above 4.2 to obtain an iron-removing aluminum solution; a magnesium removal unit 92, which has a fluoride inlet and an iron-removing aluminum solution inlet, and the iron-removing aluminum solution inlet is connected to the outlet of the pH adjustment unit 91, and the magnesium removal unit 92 is used to remove magnesium impurities in the iron-removing aluminum solution to obtain a magnesium removal solution; a copper-zinc removal unit 93, which has a magnesium removal solution inlet and a sulfide inlet, and the magnesium removal solution inlet is connected to the outlet of the magnesium removal unit 92, and the sulfide inlet is used to introduce sulfide salts and / or hydrogen sulfide, and the copper-zinc removal unit 93 is used to remove copper impurities and zinc impurities in the magnesium solution to obtain a solution product containing nickel, cobalt and manganese. Alternatively, the impurity removal unit 90 is an extraction impurity removal unit. When the extraction impurity removal unit is used, the extractant is preferably a P204 extractant.

[0063] In a preferred embodiment, the recovery device further includes a reduction smelting unit 110, which is arranged on a flow path connecting the water leaching slag inlet and the water leaching unit 60, and the reduction smelting unit 110 also has a flux inlet, and the reduction smelting unit 110 is used to reduce and smelt the water leaching slag to obtain a nickel-cobalt-manganese alloy, and the acid leaching unit 80 is used to acid-leach the nickel-cobalt-manganese alloy to obtain an acid leaching solution. In this way, the reduction smelting process can more fully reduce and enrich the nickel, cobalt and manganese in the water leaching slag, and the reduction smelting process also solves the problems of fluorine dispersion and difficulty in opening the circuit that plague the power battery recovery process, and can obtain F-containing smelting slag, realize partial opening of the F element, and take into account the disposal of harmful substances while recycling resources. Preferably, the first flue gas generated in the above-mentioned pyrometallurgical pretreatment process can obtain fluorine-containing gypsum slag after post-treatment, and it can also be sent to the reduction smelting process for coordinated treatment, which is more conducive to improving the environmental friendliness of the process.

[0064] More preferably, the reduction smelting unit 110 further comprises a second reducing agent inlet for introducing the reducing agent into the reduction smelting unit 110 to complete the reduction smelting of the water-leached slag.

[0065] In order to further improve the harmlessness of the process, in a preferred embodiment, the pyrometallurgical pretreatment unit 10 also has a first flue gas outlet, the reduction smelting unit 110 also has a second flue gas outlet, and the recovery device further includes a flue gas treatment unit 120, which is respectively connected to the first flue gas outlet and the second flue gas outlet. Preferably, the flue gas treatment unit 120 includes a secondary combustion unit, a surface cooling unit, a dust removal unit, and an exhaust gas purification unit which are connected in sequence, and the secondary combustion unit is respectively connected to the first flue gas outlet and the second flue gas outlet.

[0066] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0067] Example 1

[0068] The battery used in the embodiment is a square ternary lithium-ion battery produced by a factory in Hunan.

[0069] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages to less than 50 mm in a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 500°C in a nitrogen atmosphere for 2 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0070] (2) The pyrolysis products are washed and classified into three particle sizes of >2mm, 0.15-2mm, and below 0.15mm and a lithium-rich solution. The three particle sizes are magnetically separated at a magnetic field strength of 240kA / m to obtain nickel, cobalt, and manganese intermediate products. The magnetic separation tailings of the two particle sizes of >2mm and 0.15-2mm are used as copper and aluminum products, with recovery rates of 90.41% and 89.51%, respectively. The magnetic separation tailings of the particle size below 0.15mm are black powder and graphite products. They are slurried with water to form a flotation slurry with a concentration of 30wt%. 500g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a C grade of 91.36% and a recovery rate of 88.59% is obtained, and the flotation tailings are black powder.

[0071] (3) The black powder and nickel-cobalt-manganese intermediate products were reduced and roasted at 500°C in a hydrogen reducing atmosphere for 1 hour to obtain reduced roasted slag. Water was used as a leaching agent to leach the roasted slag at a liquid-to-solid ratio of 3:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water-leached slag and lithium-containing leachate were obtained. The lithium-containing solution obtained from the beneficiation process and the lithium-containing leachate obtained from water leaching were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 98.6%.

[0072] (4) The water-leached slag, flux quartz sand and limestone, and reducing agent coke are reduced and smelted at 1600°C for 2 hours to obtain nickel-cobalt-manganese alloy and smelting slag. The smelting slag is harmless after high-temperature solidification and can be directly landfilled. The flue gas generated by the reduction smelting is discharged after secondary combustion, waste heat boiler, surface cooling, high-temperature bag dust collection and tail gas purification absorption.

[0073] (5) Nickel-cobalt-manganese alloy was leached using 5.5 mol / L sulfuric acid, a liquid-to-solid ratio of 5:1, a temperature of 90°C, and a period of 1 h. The acid leaching solution obtained by leaching was extracted and impurities were removed using P204 to obtain a purified nickel-cobalt-manganese solution that can be used as a raw material for downstream lithium-ion battery material manufacturers.

[0074] (6) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 90.41% and 89.51%, respectively, the recovery rate of graphite reaches 88.59%, the purity of lithium carbonate obtained by wet lithium extraction is 99.7%, and the recovery rates of lithium, nickel, cobalt and manganese are 98.6%, 99.1%, 99.3% and 98.7%, respectively.

[0075] Example 2

[0076] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Jiangsu.

[0077] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages to less than 50 mm in a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 600°C in a nitrogen atmosphere for 3 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0078] (2) The pyrolysis products are washed and classified into three particle sizes of >3mm, 0.2-3mm, and below 0.2mm and a lithium-rich solution. The three particle sizes are magnetically separated at a magnetic field strength of 200kA / m to obtain nickel, cobalt, and manganese intermediate products. The magnetic tailings of the two particle sizes of >3mm and 0.2-3mm are used as copper and aluminum products, with recovery rates of 89.29% and 90.88% respectively. The magnetic tailings of the particle size below 0.2mm are black powder and graphite products. They are slurried with water to form a flotation slurry with a concentration of 15wt%. 400g / t of sodium sulfide, 150g / t of diesel, and 45g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 92.87% and a recovery rate of 87.46% is obtained, and the flotation tailings are black powder.

[0079] (3) The black powder and nickel-cobalt-manganese intermediate products were reduced and roasted in a hydrogen reducing atmosphere at 450°C for 1.5 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag at a liquid-to-solid ratio of 5:1, 60°C, and leaching for 1 hour. After solid-liquid separation, water leaching slag and lithium-containing leachate were obtained. The lithium-containing solution obtained from the beneficiation process and the lithium-containing leachate obtained from water leaching were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 99.6%.

[0080] (4) The water-leached slag, flux quartz sand and limestone, and reducing agent coal are reduced and smelted at 1500℃ for 3 hours to obtain nickel-cobalt alloy and smelting slag. The smelting slag is harmless after high-temperature solidification and can be directly landfilled. The flue gas generated by the reduction smelting is discharged after secondary combustion, waste heat boiler, surface cooling, high-temperature bag dust collection and tail gas purification absorption.

[0081] (5) Nickel-cobalt alloy was leached using 5 mol / L sulfuric acid, a liquid-to-solid ratio of 6:1, a temperature of 90°C, and a period of 1 h. The acidic leaching solution obtained by leaching was extracted and impurities were removed using P204 to obtain a purified solution of nickel, cobalt, and manganese, which can be used as a raw material for downstream lithium-ion battery material manufacturers.

[0082] (6) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in the copper and aluminum products can reach 89.29% and 90.88%, the recovery rate of graphite reaches 87.46%, the purity of lithium carbonate obtained by wet lithium extraction is 99.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 99.6%, 99.3%, 99.4% and 98.9% respectively.

[0083] Example 3

[0084] The difference from Example 1 is that there is no reduction smelting step. The specific process is as follows:

[0085] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages to less than 50 mm in a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 500°C in a nitrogen atmosphere for 2 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0086] (2) The pyrolysis products are washed and classified into three particle sizes of >2mm, 0.15-2mm, and below 0.15mm and a lithium-rich solution. The three particle sizes are magnetically separated at a magnetic field strength of 240kA / m to obtain nickel, cobalt, and manganese intermediate products. The magnetic separation tailings of the two particle sizes of >2mm and 0.15-2mm are used as copper and aluminum products, with recovery rates of 90.37% and 89.15%, respectively. The magnetic separation tailings of the particle size below 0.15mm are black powder and graphite products. They are slurried with water to form a flotation slurry with a concentration of 30wt%. 200g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a C grade of 91.42% and a recovery rate of 88.93% is obtained, and the flotation tailings are black powder.

[0087] (3) The black powder and nickel-cobalt-manganese intermediate products were reduced and roasted at 500°C in a hydrogen reducing atmosphere for 1 hour to obtain reduced roasted slag. Water was used as a leaching agent to leach the roasted slag at a liquid-to-solid ratio of 3:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water-leached slag and lithium-containing leachate were obtained. The lithium-containing solution obtained from the beneficiation process and the lithium-containing leachate obtained from water leaching were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 98.6%.

[0088] (4) The water-leached residue obtained in step (3) is leached with sulfuric acid having a concentration of 4.6 mol / L to obtain a leaching solution containing nickel, cobalt and manganese. After neutralization precipitation is used to remove iron and aluminum (pH value is 4.4), sodium sulfide is used to remove copper and zinc, and sodium fluoride is used to remove magnesium, a purified solution is obtained, and the purified solution is a solution product containing nickel, cobalt and manganese.

[0089] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 90.37% and 89.15%, respectively, the recovery rate of graphite reaches 88.93%, the purity of lithium carbonate obtained by wet lithium extraction is 99.7%, and the recovery rates of lithium, nickel, cobalt and manganese are 98.5%, 98.9%, 98.2% and 98.1%, respectively.

[0090] Example 4

[0091] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Zhejiang.

[0092] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages under a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 600°C in a nitrogen atmosphere for 3 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0093] (2) The pyrolysis products are washed and classified into three particle sizes of >5mm, 0.45-5mm, and below 0.45mm and a lithium-rich solution. The three particle sizes are respectively subjected to magnetic separation at a magnetic field strength of 220kA / m to obtain nickel-cobalt-manganese intermediate products. The magnetic separation tailings of the two particle sizes of >5mm and 0.45-5mm are used as copper and aluminum products, with recovery rates of 92.47% and 90.37%, respectively. The magnetic separation tailings of the particle size below 0.45mm are black powder and graphite products, which are slurried with water to form a flotation slurry with a concentration of 10wt%. 1000g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 91.17% and a recovery rate of 88.10% is obtained. The flotation tailings are black powder and nickel-cobalt-manganese intermediate products that enter the subsequent reduction roasting process.

[0094] (3) The black powder nickel-cobalt-manganese intermediate product was reduced and roasted at 450°C in a hydrogen reducing atmosphere for 1.5 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag at a liquid-to-solid ratio of 4:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water leached slag and lithium-containing leachate were obtained. The lithium-rich solution and the lithium-containing leachate were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 99.6%.

[0095] (4) The water-leached residue obtained in step (3) is leached with sulfuric acid having a concentration of 5 mol / L to obtain a leaching solution containing nickel, cobalt and manganese. After neutralization precipitation is used to remove iron and aluminum (pH value is 4.6), sodium sulfide is used to remove copper and zinc, and sodium fluoride is used to remove magnesium, a purified solution is obtained, and the purified solution is a solution product containing nickel, cobalt and manganese.

[0096] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 92.47% and 90.37%, respectively, the recovery rate of graphite reaches 88.10%, the purity of lithium carbonate obtained by wet lithium extraction is 99.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 98.6%, 99.3%, 99.5% and 99.2%, respectively.

[0097] Example 5

[0098] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Zhejiang.

[0099] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages under a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 400°C in a nitrogen atmosphere for 6 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0100] (2) The pyrolysis products are washed and classified into three particle sizes of >5mm, 0.2-5mm, and 0.20mm and below and a lithium-rich solution. The three particle sizes are respectively subjected to magnetic separation at a magnetic field strength of 280kA / m to obtain nickel-cobalt-manganese intermediate products. The magnetic separation tailings of the two particle sizes of >20mm and 0.2-5mm are used as copper and aluminum products, with recovery rates of 93.19% and 91.42%, respectively. The magnetic separation tailings of the particle size below 0.20mm are black powder and graphite products, which are slurried with water to form a flotation slurry with a concentration of 5wt%. 1000g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 92.82% and a recovery rate of 87.36% is obtained. The flotation tailings are black powder and nickel-cobalt-manganese intermediate products that enter the subsequent reduction roasting process.

[0101] (3) The black powder nickel-cobalt-manganese intermediate product was reduced and roasted at 750°C in a hydrogen reduction atmosphere for 1.5 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag under the conditions of a liquid-to-solid ratio of 4:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water leached slag and lithium-containing leachate were obtained. The lithium-rich solution and the lithium-containing leachate were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 69.6%.

[0102] (4) The water-leached residue obtained in step (3) is leached with sulfuric acid having a concentration of 5 mol / L to obtain a leaching solution containing nickel, cobalt and manganese. After neutralization precipitation is used to remove iron and aluminum (pH value is 4.6), sodium sulfide is used to remove copper and zinc, and sodium fluoride is used to remove magnesium, a purified solution is obtained, and the purified solution is a solution product containing nickel, cobalt and manganese.

[0103] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in the copper and aluminum products can reach 92.47% and 90.37%, respectively, the recovery rate of graphite reaches 88.10%, the purity of lithium carbonate obtained by wet lithium extraction is 99.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 69.6%, 99.3%, 99.5% and 99.2%, respectively.

[0104] Example 6

[0105] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Zhejiang.

[0106] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages under a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 700°C in a nitrogen atmosphere for 0.5h to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0107] (2) The pyrolysis products are washed and classified into three particle sizes of >3mm, 0.20-3mm, and below 0.20mm and a lithium-rich solution. The three particle sizes are magnetically separated at a magnetic field strength of 40kA / m to obtain nickel-cobalt-manganese intermediate products. The magnetic separation tailings of the two particle sizes of >3mm and 0.20-3mm are used as copper and aluminum products, with recovery rates of 93.98% and 92.13%, respectively. The magnetic separation tailings of the particle size below 0.20mm are black powder and graphite products, which are slurried with water to form a flotation slurry with a concentration of 35wt%. 1000g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 87.05% and a recovery rate of 87.29% is obtained. The flotation tailings are black powder and nickel-cobalt-manganese intermediate products that enter the subsequent reduction roasting process.

[0108] (3) The black powder nickel-cobalt-manganese intermediate product was reduced and roasted at 650°C in a hydrogen reducing atmosphere for 7 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag under the conditions of a liquid-to-solid ratio of 4:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water leached slag and lithium-containing leachate were obtained. The lithium-rich solution and the lithium-containing leachate were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 77.6%.

[0109] (4) The water-leached residue obtained in step (3) is leached with sulfuric acid having a concentration of 5 mol / L to obtain a leaching solution containing nickel, cobalt and manganese. After neutralization precipitation is used to remove iron and aluminum (pH value is 4.6), sodium sulfide is used to remove copper and zinc, and sodium fluoride is used to remove magnesium, a purified solution is obtained, and the purified solution is a solution product containing nickel, cobalt and manganese.

[0110] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 92.47% and 90.37%, respectively, the recovery rate of graphite reaches 88.10%, the purity of lithium carbonate obtained by wet lithium extraction is 98.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 77.6%, 99.3%, 99.5% and 99.2%, respectively.

[0111] Example 7

[0112] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Zhejiang.

[0113] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages under a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 640°C in a nitrogen atmosphere for 2 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0114] (2) The pyrolysis products are washed and classified into three particle sizes of >2mm, 0.15-2mm, and below 0.15mm and a lithium-rich solution. The three particle sizes are magnetically separated at a magnetic field strength of 180kA / m to obtain nickel-cobalt-manganese intermediate products. The magnetic separation tailings of the two particle sizes of >2mm and 0.15-2mm are used as copper and aluminum products, with recovery rates of 92.89% and 91.22% respectively. The magnetic separation tailings of the particle size below 0.15mm are black powder and graphite products, which are slurried with water to form a flotation slurry with a concentration of 20wt%. 1000g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 90.33% and a recovery rate of 87.11% is obtained. The flotation tailings are black powder and nickel-cobalt-manganese intermediate products that enter the subsequent reduction roasting process.

[0115] (3) The black powder nickel-cobalt-manganese intermediate product was reduced and roasted at 350°C in a hydrogen reducing atmosphere for 5 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag under the conditions of a liquid-to-solid ratio of 4:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water leaching slag and lithium-containing leachate were obtained. The lithium-rich solution and the lithium-containing leachate were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 23.5%.

[0116] (4) The water-leached residue obtained in step (3) is leached with sulfuric acid having a concentration of 5 mol / L to obtain a leaching solution containing nickel, cobalt and manganese. After neutralization precipitation is used to remove iron and aluminum (pH value is 4.6), sodium sulfide is used to remove copper and zinc, and sodium fluoride is used to remove magnesium, a purified solution is obtained, and the purified solution is a solution product containing nickel, cobalt and manganese.

[0117] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 92.47% and 90.37%, respectively, the recovery rate of graphite reaches 88.10%, the purity of lithium carbonate obtained by wet lithium extraction is 99.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 23.5%, 99.3%, 99.5% and 99.2%, respectively.

[0118] Example 8

[0119] The battery used in the embodiment is a cylindrical 18650 ternary lithium-ion battery produced by a factory in Zhejiang.

[0120] (1) The waste ternary lithium-ion batteries are treated by chemical discharge, and the discharged batteries are crushed in multiple stages under a nitrogen atmosphere. The crushed batteries are pre-treated by pyrolysis at 610°C in a nitrogen atmosphere for 3 hours to obtain pyrolysis products. The generated pyrolysis flue gas is discharged after secondary combustion, surface cooling, high-temperature bag dust collection, and tail gas purification.

[0121] (2) The pyrolysis products are washed and classified into three particle sizes of >2mm, 0.15-2mm, and below 0.15mm and a lithium-rich solution. The three particle sizes are respectively subjected to magnetic separation at a magnetic field strength of 180kA / m to obtain nickel-cobalt-manganese intermediate products. The magnetic separation tailings of the two particle sizes of >2mm and 0.15-2mm are used as copper and aluminum products, with recovery rates of 89.04% and 89.12%, respectively. The magnetic separation tailings of the particle size below 0.15mm are black powder and graphite products, which are slurried with water to form a flotation slurry with a concentration of 15wt%. 1000g / t of sodium sulfide, 200g / t of diesel, and 40g / t of pine oil are added to the flotation slurry for graphite flotation. After flotation, graphite with a carbon grade of 89.59% and a recovery rate of 88.40% is obtained. The flotation tailings are black powder and nickel-cobalt-manganese intermediate products that enter the subsequent reduction roasting process.

[0122] (3) The black powder nickel-cobalt-manganese intermediate product was reduced and roasted at 480°C in a hydrogen reducing atmosphere for 2 hours to obtain reduced roasted slag. Water was used as a leaching agent to leach the hydrogen reduced roasted slag at a liquid-to-solid ratio of 4.5:1, 80°C, and leaching for 1 hour. After solid-liquid separation, water leached slag and lithium-containing leachate were obtained. The lithium-rich solution and the lithium-containing leachate were combined, and CO2 was introduced for evaporation and crystallization to obtain a lithium carbonate product. The comprehensive recovery rate of lithium was 99.1%.

[0123] (4) The water-leached slag, flux quartz sand and limestone, and reducing agent coal are reduced and smelted at 1200°C for 5 hours to obtain nickel-cobalt alloy and smelting slag. The smelting slag is harmless after high-temperature solidification and can be directly landfilled. The flue gas generated by the reduction smelting is discharged after secondary combustion, waste heat boiler, surface cooling, high-temperature bag dust collection and tail gas purification absorption.

[0124] (5) After the combined comprehensive recovery process of metallurgy, the purity of the products obtained is as follows: the recovery rates of copper and aluminum in copper and aluminum products can reach 92.47% and 90.37%, respectively, the recovery rate of graphite reaches 88.10%, the purity of lithium hydroxide obtained by wet lithium extraction is 99.8%, and the recovery rates of lithium, nickel, cobalt and manganese are 99.1%, 99.3%, 99.5% and 99.2%, respectively.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for comprehensive recovery of waste lithium-ion batteries by metallurgy and selection, characterized in that: The recovery method comprises the following steps: S1, performing pyrometallurgical pretreatment on the waste lithium-ion battery to obtain a pretreatment product; the pyrometallurgical pretreatment process comprises: dismantling and crushing the waste lithium-ion battery to obtain crushed materials with a particle size of less than 50 mm; performing low-temperature pyrolysis on the crushed materials under a protective atmosphere at a temperature of 610-640° C. to obtain the pretreatment product; S2, washing and classifying the pre-treated product to obtain coarse-grained particles, medium-fine-grained particles, fine-grained particles and the first part of lithium-containing solution, wherein the particle size of the coarse-grained particles is larger than that of the medium-fine-grained particles, and the particle size of the medium-fine-grained particles is larger than that of the fine-grained particles; S3, respectively magnetically separating the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles, and obtaining the magnetically separated concentrate as the nickel-cobalt-manganese intermediate product, and the magnetically separated tailings of the coarse-grained particles and the medium-fine-grained particles as the copper-aluminum product, and the magnetically separated tailings of the fine-grained particles as the graphite and black powder products; and sequentially performing slurry mixing and graphite flotation on the graphite and black powder products to obtain graphite products and black powder; S4, reducing and roasting the nickel-cobalt-manganese intermediate product and the black powder to obtain roasted slag; leaching lithium from the roasted slag to obtain a second lithium-containing solution and leached slag; the reducing agent used in the reduction roasting process is the graphite product obtained in step S3; S5, combining the first part of the lithium-containing solution and the second part of the lithium-containing solution to obtain a combined solution; and preparing a lithium product using the combined solution; S6, acid leaching and impurity removal of the water leaching residue to obtain a solution product containing nickel, cobalt and manganese.

2. The recycling method according to claim 1, characterized in that: In the step S1, the low-temperature pyrolysis time is 0.5 to 6 hours.

3. The recycling method according to claim 2, characterized in that: Before the step of dismantling and crushing the waste lithium-ion battery, the step S1 also includes the step of discharging the waste lithium-ion battery.

4. The recycling method according to claim 1, characterized in that: In step S2, the particle size of the coarse-grained particles is greater than 2 mm, the particle size of the fine-grained particles is less than 0.2 mm, and the particle size of the medium-fine-grained particles is between the particle sizes of the coarse-grained particles and the fine-grained particles.

5. The recycling method according to claim 4, characterized in that: In the step S3, the magnetic field strengths for the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles are respectively 40-280 kA / m.

6. The recycling method according to claim 4, characterized in that: The steps of sequentially slurrying the graphite and black powder products and flotation of graphite include: The graphite and black powder products are mixed with water to form a flotation slurry with a concentration of 5 to 35 wt %; A regulator, a graphite collector and a frother are added to the flotation pulp to carry out graphite flotation to obtain the graphite product and the black powder.

7. The recovery method according to any one of claims 1 to 5, characterized in that: In step S4, the temperature of the reduction roasting process is 400-700° C., and the reaction time is 0.5-6 hours.

8. The recovery method according to any one of claims 1 to 5, characterized in that: In step S5, the lithium in the combined solution is evaporated and crystallized in the form of lithium hydroxide, or carbon dioxide is introduced into the combined solution or a soluble carbonate is added to precipitate the lithium in the form of lithium carbonate to obtain the lithium product.

9. The recycling method according to claim 8, characterized in that: Before the step of using the combined solution to prepare the lithium product, the step S5 further includes the step of removing impurity ions in the combined solution by chemical precipitation or ion exchange resin.

10. The recovery method according to any one of claims 1 to 5, characterized in that: In the step S6, the water leaching residue is subjected to acid leaching to obtain an acid leaching solution; The impurity removal step comprises: The pH value of the acid leaching solution is adjusted to above 4.2, and iron and aluminum impurities are removed to obtain an iron and aluminum removal solution; Adding fluoride to the iron-aluminum removal solution to remove magnesium impurities and obtain a magnesium removal solution; the fluoride is sodium fluoride; Adding sulfide salt and / or hydrogen sulfide to the magnesium removal solution to remove copper impurities and zinc impurities to obtain the nickel-cobalt-manganese containing solution product; the sulfide salt is sodium sulfide; Alternatively, the impurity removal step comprises: The acid leaching solution is extracted by an extractant to obtain the solution product containing nickel, cobalt and manganese; the extractant is P204 extractant.

11. The recycling method according to claim 7, characterized in that: Before the step of acid leaching the water-leached slag, the step S6 further includes the step of reduction smelting the water-leached slag.

12. The recycling method according to claim 11, characterized in that: The water-leached slag is reduction-smelted at a temperature of 1200-1600° C. for 0.5-5 h to obtain a nickel-cobalt-manganese alloy, and then the nickel-cobalt-manganese alloy is successively subjected to the acid leaching and impurity removal to obtain the nickel-cobalt-manganese-containing solution product.

13. The recycling method according to claim 11, characterized in that: The first flue gas is obtained in the pyrometallurgical pretreatment step, and the second flue gas is obtained in the reduction smelting step. The recovery method also includes the steps of performing secondary combustion, surface cooling, dust removal, and tail gas purification on the first flue gas and the second flue gas in sequence.

14. The recycling method according to claim 1, characterized in that: The waste lithium-ion batteries are one or more of waste lithium cobalt oxide batteries, lithium manganese oxide batteries, nickel-manganese binary composite lithium-ion batteries, nickel-cobalt binary composite lithium-ion batteries, cobalt-manganese binary composite lithium-ion batteries, nickel-cobalt-manganese ternary composite lithium-ion batteries, and nickel-cobalt-aluminum ternary composite lithium-ion batteries.

15. A comprehensive recovery device for the selection and smelting of waste lithium-ion batteries, characterized in that: The recovery device comprises: A pyrometallurgical pretreatment unit (10) having an inlet for waste lithium-ion batteries and an outlet for pretreatment products, the pyrometallurgical pretreatment unit (10) being used to perform pyrometallurgical pretreatment on the waste lithium-ion batteries to obtain pretreatment products; The pyrometallurgical pretreatment unit (10) further comprises: a disassembly and crushing unit (11), having an inlet for the waste lithium-ion battery and an outlet for crushed materials, for obtaining crushed materials with a particle size of less than 50 mm; a low-temperature pyrolysis unit (12), having an inlet for crushed materials, an inert gas inlet and an outlet for the pretreatment product, the inlet for crushed materials being connected to the outlet for crushed materials, for performing low-temperature pyrolysis on the crushed materials under a protective atmosphere at a temperature of 610-640° C., for obtaining the pretreatment product; A ore washing and classification unit (20) having a pretreatment product inlet and a first water inlet, wherein the pretreatment product inlet is connected to the pretreatment product inlet, and the ore washing and classification unit (20) is used to perform ore washing and classification on the pretreatment product to obtain coarse particles, medium-fine particles, fine particles and a first portion of lithium-containing solution, wherein the particle size of the coarse particles is larger than the particle size of the medium-fine particles, and the particle size of the medium-fine particles is larger than the particle size of the fine particles; a magnetic separation unit (30) connected to the outlet of the ore washing and classification unit (20), the magnetic separation unit (30) being used to magnetically separate the coarse-grained particles, the medium-fine-grained particles and the fine-grained particles respectively to obtain nickel-cobalt-manganese intermediate products, coarse-grained particle magnetic separation tailings, medium-fine-grained particle magnetic separation tailings and fine-grained particle magnetic separation tailings, the coarse-grained particle magnetic separation tailings and the medium-fine-grained particle magnetic separation tailings are used as copper and aluminum products, and the fine-grained particle magnetic separation tailings are graphite and black powder products; A graphite recovery unit (40) is connected to the outlet of the magnetic separation unit (30), the graphite recovery unit (40) comprising a slurry mixing unit (41) and a flotation unit (42) connected in sequence, the slurry mixing unit (41) is used to perform slurry mixing on the graphite and black powder products, and the flotation unit (42) is used to perform graphite flotation to obtain graphite products and black powder; a reduction roasting unit (50), connected to the outlet of the magnetic separation unit (30) and the outlet of the flotation unit (42), respectively, and the reduction roasting unit (50) is used to carry out reduction roasting on the nickel-cobalt-manganese intermediate product and the black powder to obtain roasted slag; The reduction roasting unit (50) further comprises a first reducing agent inlet, which is connected to the outlet of the flotation unit (42) and is used to use the graphite product obtained in the graphite flotation process as a reducing agent in the reduction roasting process; a water leaching unit (60) comprises a roasting slag inlet and a second water inlet, the roasting slag inlet is connected to the outlet of the reduction roasting unit (50), and the water leaching unit (60) is used to water-leach the roasting slag to extract lithium to obtain a second portion of lithium-containing solution and water-leached slag; a lithium recovery unit (70), the inlet of which is respectively connected to the outlet of the water leaching unit (60) and the outlet of the ore washing and classification unit (20), the lithium recovery unit (70) being used to prepare a lithium product using a combined solution of the first lithium-containing solution and the second lithium-containing solution; an acid leaching unit (80) having a water leaching residue inlet, an acid inlet and an acid leaching liquid outlet, wherein the water leaching residue inlet is connected to the outlet of the water leaching unit (60), and the acid leaching unit (80) is used to acid-leach the water leaching residue to obtain an acid leaching liquid; An impurity removal unit (90) is connected to the acid leaching solution outlet, and the impurity removal unit (90) is used to remove impurities from the acid leaching solution to obtain a solution product containing nickel, cobalt and manganese.

16. The recovery device according to claim 15, characterized in that: The pyrometallurgical pretreatment unit (10) further comprises a discharge unit (13), the discharge unit (13) being located upstream of the dismantling and crushing unit (11) and connected to the waste lithium-ion battery inlet, the discharge unit (13) being used to perform discharge treatment on the waste lithium-ion batteries.

17. The recovery device according to claim 15 or 16, characterized in that: The graphite recovery unit (40) further comprises: An adjusting agent supply unit (43), connected to the flotation unit (42) and used to supply an adjusting agent thereto; A graphite collector supply unit (44), connected to the flotation unit (42) and used to supply a graphite collector thereto; A frothing agent supply unit (45) is connected to the flotation unit (42) and is used to supply the frothing agent thereto.

18. The recovery device according to claim 15 or 16, characterized in that: The reduction roasting unit (50) further comprises a reducing gas inlet, and the recovery device further comprises a reducing gas supply unit, wherein the reducing gas supply unit is connected to the reducing gas inlet.

19. The recovery device according to claim 18, characterized in that: The recovery device further comprises an inert gas supply unit (100), wherein the inert gas supply unit (100) is respectively connected to the reducing gas inlet and the inert gas inlet of the low-temperature pyrolysis unit (12).

20. The recovery device according to claim 15 or 16, characterized in that: The lithium recovery unit (70) comprises: An impurity removing agent supply unit (71), used for supplying an impurity removing agent; an impurity removal and purification unit (72), the inlet of which is respectively connected to the outlet of the water immersion unit (60), the outlet of the ore washing and classification unit (20), and the impurity removal agent supply unit (71), the impurity removal and purification unit (72) being used to carry out an impurity removal reaction on a combined solution of the first part of the lithium-containing solution and the second part of the lithium-containing solution to obtain an impurity-removed lithium solution; A lithium product preparation unit (73) is connected to the outlet of the impurity removal and purification unit (72), and the lithium product preparation unit (73) is used to evaporate and crystallize the impurity-removed lithium solution or precipitate lithium carbonate to obtain the lithium product.

21. The recovery device according to claim 15 or 16, characterized in that: The impurity removal unit (90) comprises: A pH adjustment unit (91) connected to the acid leaching liquid outlet, the pH adjustment unit (91) being used to adjust the pH value of the acid leaching liquid to above 4.2 to obtain an iron and aluminum removal solution; a magnesium removal unit (92) having a fluoride inlet and an iron removal aluminum solution inlet, wherein the iron removal aluminum solution inlet is connected to the outlet of the pH adjustment unit (91), and the magnesium removal unit (92) is used to remove magnesium impurities in the iron removal aluminum solution to obtain a magnesium removal solution; The copper-zinc removal unit (93) has a magnesium removal solution inlet and a sulfide inlet, the magnesium removal solution inlet is connected to the outlet of the magnesium removal unit (92), the sulfide inlet is used to introduce sulfide salt and / or hydrogen sulfide, and the copper-zinc removal unit (93) is used to remove copper impurities and zinc impurities in the magnesium removal solution to obtain the solution product containing nickel, cobalt and manganese; Alternatively, the impurity removal unit (90) is an extraction impurity removal unit.

22. The recovery device according to claim 21, characterized in that The recovery device further comprises a reduction smelting unit (110), wherein the reduction smelting unit (110) is arranged on a flow path connecting the water leaching slag inlet and the water leaching unit (60), and the reduction smelting unit (110) further comprises a flux inlet, the reduction smelting unit (110) is used for reduction smelting the water leaching slag to obtain a nickel-cobalt-manganese alloy, and the acid leaching unit (80) is used for acid leaching the nickel-cobalt-manganese alloy to obtain the acid leaching solution.

23. The recovery device according to claim 22, characterized in that: The pyrometallurgical pretreatment unit (10) further comprises a first flue gas outlet, the reduction smelting unit (110) further comprises a second flue gas outlet, and the recovery device further comprises a flue gas treatment unit (120), wherein the flue gas treatment unit (120) is respectively connected to the first flue gas outlet and the second flue gas outlet.

Images