Retired lithium battery and waste catalyst combined collaborative smelting recovery method and application

Abstract

The invention relates to a decommissioned lithium battery and waste catalyst combined collaborative smelting recovery method and application, and relates to the technical field of waste recycling and metal regeneration. According to the recovery method, organic matters and graphite in the retired battery can be used as reducing agents, and carrier components (such as Al2O3 and SiO2) rich in the waste catalyst can be used for forming an ideal slag system, so that multi-metal synchronous reduction, alloying and byproduct recovery are realized in a single smelting process, the overall energy consumption is reduced, and the environmental benefits are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste resource utilization and metal recycling, and particularly to a method for co-smelting and recycling retired lithium batteries and waste catalysts and its application. Background Art

[0002] With the large-scale application of new energy vehicles, energy storage systems and electronic products, the number of retired lithium-ion batteries has increased sharply, which are rich in valuable metals such as nickel (Ni), cobalt (Co), manganese (Mn), and lithium (Li). Traditional recovery methods mainly include two processes: pyrometallurgy and hydrometallurgy. Pyrometallurgy has the advantages of simple process, strong adaptability, and can reduce and form alloys of metals such as Ni and Co in a single high-temperature smelting, which is suitable for treating mixed materials. However, high-temperature smelting has high energy consumption, some metals (such as lithium and some Mn) are likely to remain in the slag, and there are more emissions of CO2 and harmful waste gases. Hydrometallurgy has the characteristics of low process temperature, high recovery rate, and high product purity, but has many processes, large consumption of acid-base reagents, high cost of waste liquid treatment, and great difficulty in industrial scale-up. In addition, for waste catalysts, traditional recovery mostly uses acid leaching, roasting and wet extraction methods, but there are problems such as high equipment investment, complex process and insufficient recovery rate of some precious metals. In the prior art, the recovery of batteries and catalysts mostly adopts independent processes, and the co-utilization of materials and energy between waste materials cannot be realized, resulting in resource waste and increased environmental burden.

[0003] In view of this, there is an urgent need for a new recovery method that directly uses retired lithium batteries and waste catalysts as raw materials to deeply recycle and utilize the economically valuable components therein, save resources, and at the same time reduce the environmental impact of the above waste materials. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method for co-smelting and recycling retired lithium batteries and waste catalysts. This recovery method can not only use the inherent organic matter and graphite in retired batteries as reducing agents, but also use the carrier components (such as Al2O3) rich in waste catalysts to form an ideal slag system, so as to realize the synchronous reduction, alloying and by-product recovery of multiple metals in a single smelting process, reduce the overall energy consumption and improve the environmental benefits.

[0005] The present invention provides a method for co-smelting and recycling retired lithium batteries and waste catalysts, including the following steps:

[0006] Raw material pretreatment and batching: Discharge, disassemble and crush the retired lithium batteries to obtain battery black powder, and dry it to obtain battery powder; crush and dry the waste catalyst to obtain catalyst powder; mix the battery powder and the catalyst powder to obtain a reduction mixture.

[0007] Co-reduction and high-temperature smelting: Under a protective atmosphere, heat the reduced mixed materials to carry out a pre-reduction reaction, and then conduct high-temperature smelting to obtain a reduced smelting product;

[0008] Slag phase regulation and product separation: Add a slag modifier to the reduced smelting product, adjust the basicity of the slag, cool it, and perform water quenching to separate the multi-element alloy from the slag, obtaining a multi-element alloy and slag. Acid leach, filter, concentrate, and precipitate lithium from the slag to obtain lithium salts.

[0009] In the above recycling method, after the retired lithium batteries are conventionally discharged, disassembled, and pulverized, only low-temperature drying is carried out to retain the graphite and organic binders therein; the waste catalyst is also simply pulverized and dried, retaining the residual grease, and mixed with the battery powder to form a mixed material for reduction, which can also serve as a combustion heat source at the same time. Then the reduced mixed material first undergoes a pre-reduction reaction, using the heat and reducing gases generated by the pyrolysis of organic matter and waste oil, and then high-temperature smelting is carried out to complete metal reduction and alloying, obtaining a reduced smelting product. A slag modifier is added to regulate the basicity of the slag, thereby obtaining a multi-element alloy and slag. Finally, based on the slag, lithium salts are recovered through processes such as acid leaching and filtration. This recycling method can not only utilize the inherent organic matter and graphite in the retired batteries as reducing agents, but also utilize the carrier components (such as Al2O3) rich in the waste catalyst to form an ideal slag system, thereby realizing the synchronous reduction, alloying of multiple metals, and recovery of by-products (such as lithium salts) in a single smelting process, reducing the overall energy consumption and improving the environmental benefits. Moreover, this recycling method has a simple process flow, high energy utilization rate, and high recovery rate, and is both environmentally friendly and economical. It is suitable for the systematic treatment of various types of retired lithium-ion batteries and metal-containing waste catalysts, and realizes the comprehensive recovery of multiple metals and lithium resources.

[0010] The above waste catalyst is a catalyst including carrier components, the carrier components include Al2O3 and / or SiO2, and the waste catalyst can be derived from the hydrotreating step of petroleum or chemical industry.

[0011] In one embodiment, in the raw material pretreatment and batching steps, the drying temperature of the battery black powder is 80 - 130 °C, and the drying time is 0.5 - 4 h; the drying temperature of the waste catalyst is 80 - 130 °C, and the drying time is 0.5 - 4 h; the mass ratio of the battery powder to the catalyst powder is (0.5 - 4):1.

[0012] In one embodiment, the mass ratio of the battery powder to the catalyst powder is (0.8 - 3):1.

[0013] In one embodiment, the mass ratio of the battery powder to the catalyst powder is (1.5 - 2.5):1.

[0014] In one embodiment, in the co-reduction and high-temperature smelting steps, the temperature of the pre-reduction reaction is 200 - 800 °C, and the time of the pre-reduction reaction is 10 - 90 min; the high-temperature smelting includes: heating to 1000 - 1800 °C at a rate of 3 - 20 °C / min and holding for 0.3 - 4 h.

[0015] In one embodiment, in the co-reduction and high-temperature smelting steps, the protective atmosphere includes an inert atmosphere or a weak reducing atmosphere.

[0016] In one embodiment, the temperature of the pre-reduction reaction is 300 - 700 °C, and the time of the pre-reduction reaction is 20 - 60 min; the high-temperature smelting includes: heating to 1100 - 1700 °C at a rate of 5 - 15 °C / min and holding for 0.5 - 3 h.

[0017] In one embodiment, the flow rate of the protective gas for the high-temperature smelting is 0.5 - 5 L / min.

[0018] In one embodiment, the flow rate of the protective gas for the high-temperature smelting is 1 - 3 L / min.

[0019] In one embodiment, the high-temperature smelting is achieved by an intermediate frequency induction furnace, a resistance furnace or an electric arc furnace.

[0020] In one embodiment, in the slag phase regulation and product separation steps, the slag conditioner includes at least 3 of CaO, SiO2, Al2O3, MgO, and Na2O, and the addition amount of the slag conditioner is 10 - 110 wt% of the mass of the reduction smelting product; the basicity of the furnace slag is adjusted to 0.5 - 2.0.

[0021] In one embodiment, the addition amount of the slag conditioner is 15 - 50 wt% of the mass of the reduction smelting product.

[0022] In one embodiment, the basicity of the furnace slag is adjusted to 0.8 - 1.5.

[0023] In one embodiment, when the slag conditioner includes CaO, SiO2, and Al2O3, the usage amounts of CaO, SiO2, and Al2O3 are 30 - 50 wt%, 30 - 40 wt%, and 1 - 20 wt% of the mass of the slag conditioner respectively;

[0024] When the slag conditioner includes CaO, SiO2, Al2O3, and MgO, the usage amounts of CaO, SiO2, Al2O3, and MgO are 30 - 45 wt%, 25 - 35 wt%, 1 - 20 wt%, and 3 - 8 wt% of the mass of the slag conditioner respectively;

[0025] When the slag conditioner includes CaO, SiO2, Al2O3, MgO, and Na2O, the dosages of CaO, SiO2, Al2O3, MgO, and Na2O are 29 - 35 wt%, 25 - 35 wt%, 1 - 20 wt%, 3 - 8 wt%, and 1 - 10 wt% of the mass of the slag conditioner, respectively.

[0026] In one embodiment, in the slag phase regulation and product separation step, the acid leaching includes acid leaching with sulfuric acid or hydrochloric acid, the solid-liquid ratio of the acid leaching is 1:(5 - 10), the temperature is 60 - 90 °C, and the time is 1 - 3 h.

[0027] In one embodiment, in the slag phase regulation and product separation step, the temperature of the water quenching is 20 - 80 °C.

[0028] In one embodiment, it further includes adding an auxiliary carbon source after raw material pretreatment and batching. The auxiliary carbon source includes graphite or waste oil;

[0029] When the auxiliary carbon source includes graphite, the molar ratio of carbon to oxygen in the metal oxide in the reduced mixed material after adding graphite is (0.8 - 2.0):1;

[0030] When the auxiliary carbon source includes waste oil, the addition amount of the waste oil is 2 - 25 wt% of the mass of the reduced mixed material.

[0031] It can be understood that when the above-mentioned reduced mixed material composed of battery powder and catalyst powder is insufficient, graphite or waste oil can be further supplemented. The graphite can be sourced from retired lithium batteries, and the waste oil can be sourced from the waste oil in waste catalysts or externally added waste oil. The molar amount of oxygen in the above-mentioned metal oxide is calculated based on the oxygen in the metal oxide in which the metals in retired lithium batteries and waste catalysts are measured as oxides. The above-mentioned waste oil is heavy oil.

[0032] In one embodiment, when the auxiliary carbon source includes graphite, the molar ratio of carbon to metal oxide in the reduced mixed material after adding graphite is (1.0 - 1.5):1.

[0033] In one embodiment, when the auxiliary carbon source includes graphite, the molar ratio of carbon to metal oxide in the reduced mixed material after adding graphite is 1.2:1.

[0034] In one embodiment, when the auxiliary carbon source includes waste oil, the addition amount of the waste oil is 5 - 20 wt% of the mass of the reduced mixed material.

[0035] In one embodiment, when the auxiliary carbon source includes waste oil, the addition amount of the waste oil is 10 - 15 wt% of the mass of the reduced mixed material.

[0036] In one embodiment, the method for co-smelting and recycling retired lithium batteries and waste catalysts further includes adding fluxes and / or fluxing agents after raw material pretreatment and batching, and the addition amount is 4-110 wt% of the mass of the reduced mixed materials.

[0037] It can be understood that those skilled in the art can choose to add or not add fluxes and / or fluxing agents according to the high-temperature smelting situation.

[0038] In one embodiment, the flux includes at least one of CaO and SiO2, the fluxing agent includes Na2CO3, and the addition amount of the flux and / or fluxing agent is 15-50 wt% of the mass of the reduced mixed materials.

[0039] The present invention also provides an application of the method for co-smelting and recycling retired lithium batteries and waste catalysts in the preparation of multi-element alloys.

[0040] The present invention also provides an application of the method for co-smelting and recycling retired lithium batteries and waste catalysts in the recovery of lithium salts.

[0041] The present invention also provides a method for preparing multi-element alloys and / or lithium salts, and the retired lithium batteries are treated by using the method for co-smelting and recycling retired lithium batteries and waste catalysts.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The method for co-smelting and recycling retired lithium batteries and waste catalysts and its application of the present invention can not only utilize the inherent organic matters and graphite in the retired batteries as reducing agents, but also utilize the carrier components (such as Al2O3) rich in the waste catalysts to form an ideal slag system, so as to realize the synchronous reduction and alloying of multiple metals in a single smelting process, and achieve the efficient co-recovery of multiple metals such as nickel, cobalt, tungsten, molybdenum, and manganese. The recovery rate of the main metals can reach more than 95%. After refining, the multi-element alloy can be used as alloy components for the production of superalloys and special steels. At the same time, the by-products (such as lithium salts) can also be recovered, and the heat generated by the combustion of the organic components in the waste batteries is utilized in this recovery method, effectively reducing the external energy consumption, thereby reducing the overall energy consumption and improving the environmental benefits. Moreover, this recovery method has obvious environmental protection advantages, reduces the generation of acid-base waste liquid, and has no large amount of harmful waste gas emissions; the process is simple and easy to scale up: the equipment is general and the process parameters are clear, which is easy to realize industrial-scale production; comprehensive utilization of resources: through the secondary recovery of lithium, the resource closed-loop is realized. Specific Embodiments

[0044] For ease of understanding of the present invention, the present invention will be described more fully below with reference to relevant embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0046] Example 1

[0047] A method for the coordinated smelting and recovery of retired lithium batteries and waste catalysts.

[0048] This method retains the carbonaceous components (such as battery graphite, organic binders, and residual catalyst grease) in retired batteries and waste catalysts, and combines them with an external slag conditioner to achieve the simultaneous reduction and alloying of multiple metals in a single pyrometallurgical smelting process, and further recovers by-products such as lithium salts from the smelting slag. This technical solution is suitable for the recovery of secondary resources containing nickel, cobalt, manganese, molybdenum, tungsten, lithium, and other valuable metals. It has a simple process flow, high energy efficiency, good environmental protection, and economic value. The specific steps of the recovery method are as follows:

[0049] 1. Pretreatment of retired batteries and spent catalysts.

[0050] In this embodiment, the retired batteries are lithium-ion batteries, which may include lithium cobalt oxide batteries, lithium nickel oxide batteries, and one or more of all types of ternary positive electrode batteries. Preferably, the retired batteries are first discharged, and then the steps of disassembly, crushing, and drying are completed in sequence to obtain battery powder with suitable particle size and retain the graphite and organic binder components in the battery as much as possible. In the preferred implementation of this embodiment, the drying temperature is 80°C to 120°C, and the time is 0.5-4h. Since this technical solution focuses on retaining the carbonaceous reducing agent, high-temperature roasting or complete removal of organic matter is no longer performed.

[0051] Similarly, for spent catalysts, this technical solution does not perform thorough deoiling or deep calcination on them, but only performs simple crushing and low-temperature drying treatments to retain their residual oil or coke components. In this embodiment, the spent catalyst includes one or more of catalysts such as W-Mo-Ni / Al2O3, W-Mo-V-Ni / Al2O3, Mo-Ni / Al2O3, etc. The drying temperature is preferably 80°C to 120°C, and the time is 0.5 - 4h; this catalyst can be rich in active components such as Ni, Co, Mo, W, V, etc., and the carrier is mostly Al2O3 or SiO2.

[0052] In this technical solution, through the above pretreatment operations, the excess moisture in the raw materials can be removed and an appropriate powder particle size can be obtained, thus laying a foundation for subsequent mixing and batching, smelting and reduction.

[0053] II. Mixing and batching.

[0054] In this embodiment, in the mixing and batching process, the retired battery powder and the spent catalyst powder are mixed according to a mass ratio of 0.5:1 - 4:1. Preferably, considering the amount of graphite and other carbon sources contained in the battery, the specific ratio can be adjusted according to actual needs. For example, 2:1 to 4:1 is more convenient for simultaneously considering the metal recovery rate and the use efficiency of the reducing agent.

[0055] During the mixing process, the dried battery powder and the catalyst powder can be first put into a mixer and mixed evenly; when it is detected that the carbon content in the mixed material is insufficient to meet the reduction requirements, an appropriate amount of graphite powder, coal or coke can be added to maintain the molar ratio of carbon to metal oxide between 0.8:1 and 2.0:1, more preferably 1.0:1 to 1.5:1. Further, to provide additional combustion calorific value and reduction atmosphere, 2 - 25wt% of waste oil (such as petroleum coke residue, etc.) is allowed to be added. The above mixing operation can be carried out using conventional mixing equipment, and the mixing time is usually 0.5h to 3h, which can ensure the uniform dispersion of each component.

[0056] III. Pre-reduction process.

[0057] In this technical solution, the pre-reduction process refers to placing the mixed material in an inert or weakly reducing protective gas environment, first heating it to 200°C to 800°C and maintaining it for 10 to 90 minutes to achieve the preliminary reduction of some metal oxides, and decomposing the residual organic binder or the oil in the catalyst at a lower temperature to provide a certain amount of heat and reduction atmosphere. Preferably, the pre-reduction temperature of the present invention can be controlled at 300°C to 700°C, and the holding time can be controlled at 20 to 60 minutes, which can not only reduce the energy consumption in the high-temperature stage but also give full play to the reduction effect of battery graphite and oil.

[0058] In a preferred embodiment of the present invention, if the protective atmosphere is an inert gas such as argon or nitrogen, the flow rate of the gas introduced can be 0.5 - 5 L / min; if it is nitrogen, 2 - 5 vol% of H2 or CO can also be added to the nitrogen to enhance the pre-reduction effect.

[0059] IV. High-temperature smelting step.

[0060] After the pre-reduction is completed, the material is continuously heated to the range of 1000 °C - 1800 °C at a heating rate of 3 - 20 °C / min and held for 0.3 - 3 h to achieve the full reduction of multi-metal oxides and the alloying of metals. Preferably, in the present invention, it is held at 1200 °C - 1600 °C for 0.5 - 2 h, which can not only meet the complete reduction of multi-metals but also take into account the energy consumption factor. At this time, if the smelting furnace is an intermediate frequency induction furnace or an electric arc furnace, the gas flow rate in the furnace can be maintained at 1 - 3 L / min and a weak reduction or inert atmosphere can be ensured, so as to obtain a higher metal recovery efficiency.

[0061] In this technical solution, the combustion of graphite in retired batteries and grease in waste catalysts can provide additional heat, and some metal oxides are reduced to metal elements by carbon; at the same time, different metals can form multi-element alloys such as Ni–Co–Mo, Ni–Co–W, Ni-Co-Mn-W-Mo, Ni-Co-Mo-Si-V, etc. at high temperatures, so as to achieve the goal of one-time alloying treatment.

[0062] V. Construction of slag modifiers and slag system during smelting.

[0063] During the above high-temperature smelting process or before the end, in this technical solution, by adding ternary, quaternary or multi-component slag modifiers (such as Al2O3–SiO2–CaO or Al2O3–SiO2–CaO–MgO or Al2O3-Na2O-SiO2-CaO-MgO, etc.), the slag phase is made to have a reasonable melting temperature and viscosity, so that valuable metals can be separated smoothly and sink and aggregate. In this technical solution, according to the characteristics of different raw materials, the addition amount of the slag modifier is controlled between 10 - 110 wt%; the above slag modifiers can be selected from the common range of slag modifiers. For example, for CaO, quicklime or fluorite can be used; for SiO2, quartz, etc. can be used. The specific ratio can refer to the following range:

[0064] When using a ternary slag system, the CaO content is 30 - 50 wt%, the SiO2 content is 30 - 40 wt%, and the Al2O3 content is 1 - 20 wt%;

[0065] When using a quaternary slag system, 3 - 8 wt% of MgO is added on the basis of the ternary system, that is, the CaO content is 30 - 45 wt%, the SiO2 content is 25 - 35 wt%, the Al2O3 content is 1 - 20 wt%, and the MgO content is 3 - 8 wt%;

[0066] When using a multi-component slag system, the CaO content is 29 - 35 wt%, the Na2O content is 1 - 10 wt%, the SiO2 content is 25 - 35 wt%, the Al2O3 content is 1 - 20 wt%, and the MgO content is 3 - 8 wt%.

[0067] By adjusting the ratios of CaO / SiO2, (CaO + MgO) / (SiO2 + Al2O3), and (CaO + MgO + Na2O) / (SiO2), the slag basicity R can be controlled between 0.8 and 2.0, preferably between 1.0 and 1.5. If the basicity is too low, it is likely to cause high slag viscosity and a decrease in metal recovery rate; if the basicity is too high, it will increase the melting point and exacerbate the corrosion of the furnace lining. In the present invention, low viscosity, low melting point of the slag, and low entrapment of metal oxides can be achieved within the intermediate range.

[0068] VI. Separation and by-product recovery after melting.

[0069] After melting is completed, this technical solution can stratify the metal phase and the slag phase through high-temperature slag skimming, natural cooling, or water quenching. To accelerate separation and facilitate subsequent lithium extraction operations, water quenching is preferred, that is, the slag is quickly put into water for cooling and quenching at the end of melting. In this way, dense metal alloy ingots and fragmented slag particles (or powders) can be obtained, achieving rapid and sufficient phase separation.

[0070] Alloy products: The separated metal phase can be ingoted or secondary refined to obtain a multi-component alloy. According to the raw material ratio and specific process control, the recovery rates of metals such as Ni, Co, Mo, W, and V generally range from 90% to 98%, and the alloy composition is uniform, which can be directly used as a master alloy for special alloys or raw materials for subsequent refining and processing.

[0071] Recovery of lithium from the slag: An important feature of this technical solution lies in the utilization of lithium resources in the slag. The slag particles obtained after water quenching are leached with dilute sulfuric acid or hydrochloric acid at a concentration of 0.5 - 2 mol / L, kept warm at 60 - 90 °C for 1 - 3 h, and the solid-liquid ratio is 1:5 - 1:10. After the leaching is completed, filtration separation is carried out to obtain a lithium-rich solution. Subsequently, lithium salt products such as lithium carbonate or lithium chloride can be prepared through conventional means such as evaporation and concentration, precipitation, or extraction; the comprehensive lithium recovery rate usually reaches over 80%.

[0072] In the present invention, this post-treatment link for the slag enables further high-value utilization of resources, and at the same time avoids the loss of lithium during high-temperature melting, forming a closed loop for comprehensive recovery of metals and lithium.

[0073] Example 2

[0074] The recycling method of Example 1 was used to recycle retired ternary lithium batteries, as specifically shown below.

[0075] After discharging, disassembling, and pulverizing the retired ternary lithium battery, it was dried at 120 °C for 3 hours to obtain 500 g of battery black powder (containing graphite and organic matter). The waste catalyst (W-Mo-Ni / Al2O3) was also dried at 120 °C for 3 hours to obtain 500 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer at a mass ratio of 1:1 to obtain a reduction mixture, and 3 wt% of CaO and 2 wt% of SiO2 were added to the reduction mixture as additives. In the reduction mixture, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide reach 1.2:1. The total amount of waste oil was controlled to be 10 wt% of the mixture.

[0076] Under the protection of an argon environment, the reduction mixture was placed in an intermediate frequency induction furnace, pre-reduced at 500 °C for 30 minutes, and then heated to 1400 °C at a rate of 10 °C / min and held for 1 hour. During the smelting process, 15 wt% of the Al2O3-SiO2-CaO slag conditioner (containing 35 wt% of CaO, 33 wt% of SiO2, 10 wt% of Al2O3, and an alkalinity of 1.06) of the reduction smelting product was added to regulate the slag phase.

[0077] After smelting, the alloy and slag were separated by water quenching at 70 °C. The obtained alloy was Ni-Co-W-Mo-Mn alloy, and the recovery rates of Ni and Co were greater than 98.5%, the recovery rate of Mn was greater than 90%, and the recovery rates of W and Mo were greater than 95%. After the slag was water quenched, it was acid leached with 1 mol / L H2SO4 solution (solid-liquid ratio 1:8, 80 °C, 2 hours), and lithium carbonate was prepared by evaporation crystallization after filtration, with a lithium recovery rate of 80%.

[0078] Example 3

[0079] The retired ternary lithium battery was recycled using the recycling method of Example 1, as shown below.

[0080] After discharging, disassembling, and pulverizing the retired ternary lithium battery, it was dried at 120 °C for 3 hours to obtain 400 g of battery black powder (containing graphite and organic matter). The waste catalyst (W-V-Ni / Al2O3) was dried at 120 °C for 3 hours to obtain 600 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer at a mass ratio of 2:3 to obtain a reduction mixture. In the reduction mixture, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide be 1.0:1. The total amount of waste oil was 10 wt% of the reduction mixture.

[0081] In a weakly reducing atmosphere with 3 vol% CO doped in argon, the reduced mixed materials were pre-reduced at 500 °C for 35 minutes, and then heated to 1400 °C at a rate of 10 °C / min and held for 45 minutes. During the smelting process, an Al2O3-SiO2-CaO-MgO slag conditioner accounting for 28 wt% of the mass of the reduced smelting product (containing 40 wt% CaO, 30 wt% SiO2, 8 wt% Al2O3, 5 wt% MgO, and an alkalinity of 1.33) was added to control the slag phase.

[0082] After smelting was completed, water quenching was used to separate the alloy from the slag. In the obtained alloy, the recovery rates of Ni reached 97%, Co reached 96%, W reached 87%, and V reached 90%. After the slag was water quenched, it was acid leached with a 1.5 mol / L HCl solution (solid-liquid ratio 1:10, 85 °C, 2.5 hours), and lithium chloride was prepared by concentration and crystallization after filtration, with a lithium recovery rate of 82%.

[0083] Example 4

[0084] The recovery method of Example 1 was used to recycle retired ternary lithium batteries, as specifically shown below.

[0085] After the retired lithium iron phosphate batteries were discharged, disassembled, and pulverized, they were dried at 120 °C for 3 hours to obtain 600 g of battery black powder (containing graphite and organic matter). The Co-Mo / Al2O3 waste catalyst was dried at 120 °C for 3 hours to obtain 400 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer at a mass ratio of 3:2 to obtain the reduced mixed materials. In the reduced mixed materials, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide 1.5:1. The total amount of waste oil was 15 wt% of the mixed materials.

[0086] In a nitrogen (doped with 2 vol% H2) environment, the reduced mixed materials were pre-reduced at 450 °C for 40 minutes, and then heated to 1300 °C at a rate of 8 °C / min and held for 1.5 hours. During the smelting process, an Al2O3-SiO2-CaO-MgO slag conditioner accounting for 18 wt% of the mass of the reduced smelting product (containing 35 wt% CaO, 32 wt% SiO2, 1.5 wt% Al2O3, 5 wt% MgO, and an alkalinity of 1.09) was added to control the slag phase.

[0087] After smelting was completed, water quenching was used to separate the alloy from the slag. In the obtained alloy, the recovery rates of Ni reached 95%, Co reached 90%, and Mn reached 88%. After the slag was water quenched, it was acid leached with a 1 mol / L H2SO4 solution (solid-liquid ratio 1:8, 80 °C, 2 hours), and lithium carbonate was prepared by evaporation and crystallization after filtration, with a lithium recovery rate of 85%.

[0088] Example 5

[0089] The recycling method of Example 1 was adopted to recycle the retired ternary lithium batteries, which is specifically as follows.

[0090] After the retired ternary lithium batteries were discharged, disassembled, and pulverized, they were dried at 120 °C for 3 hours to obtain 700 g of battery black powder (containing graphite and organic matter). The waste catalyst (Mo-Ni / Al2O3) was dried at 120 °C for 3 hours to obtain 300 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer according to a mass ratio of 7:3 to obtain a reduced mixed material. In the reduced mixed material, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide 1.2:1. The total amount of waste oil was 10 wt% of the mixed material.

[0091] Under the protection of an argon environment, the reduced mixed material was pre-reduced at 550 °C for 30 minutes, and then heated to 1550 °C at a rate of 8 °C / min and held for 1.2 hours. During the smelting process, 15 wt% of the Al2O3-SiO2-CaO slag conditioner (containing 32 wt% CaO, 35 wt% SiO2, 15 wt% Al2O3, and basicity 0.91) of the mass of the reduced smelting product was added to regulate the slag phase.

[0092] After smelting, water quenching was used to separate the alloy from the slag. In the obtained alloy, the Ni recovery rate was 98%, the Co recovery rate was 96%, and the Mo recovery rate was 97%. After the slag was water quenched, it was acid leached with a 1 mol / L H2SO4 solution (solid-liquid ratio 1:8, 80 °C, 2 hours), and lithium carbonate was prepared by evaporation and crystallization after filtration. The lithium recovery rate reached 87%.

[0093] Example 6

[0094] The recycling method of Example 1 was adopted to recycle the retired ternary lithium batteries, which is specifically as follows.

[0095] After the retired ternary lithium batteries were discharged, disassembled, and pulverized, they were dried at 120 °C for 3 hours to obtain 600 g of battery black powder (containing graphite and organic matter). The waste catalyst (W-Mo-Ni / Al2O3) was dried at 120 °C for 3 hours to obtain 400 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer according to a mass ratio of 3:2 to obtain a reduced mixed material. In the reduced mixed material, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide 1.2:1. The total amount of waste oil was 10 wt% of the reduced mixed material.

[0096] In a nitrogen environment containing 2 vol% H2, the reduced mixed material was pre-reduced at 600 °C for 40 minutes, and then heated to 1500 °C at a rate of 10 °C / min and held for 1.5 hours. During the smelting process, an Al2O3-SiO2-CaO-MgO slag conditioner (containing 38 wt% CaO, 32 wt% SiO2, 18 wt% Al2O3, 5 wt% MgO, basicity 1.19) accounting for 20 wt% of the mass of the reduced smelting product was added to control the slag phase.

[0097] After smelting was completed, water quenching at 80 °C was used to separate the alloy from the slag. In the obtained alloy, the recovery rates of Ni, Co, Mo, and W reached 98%, 97%, 96%, and 95% respectively. After the slag was water quenched, acid leaching was carried out with a 1.5 mol / L HCl solution (solid-liquid ratio 1:10, 85 °C, 2.5 hours). After filtration, lithium chloride was prepared by concentration and crystallization, and the lithium recovery rate reached 92%.

[0098] Example 7

[0099] The recovery method of Example 1 was used to recycle retired ternary lithium batteries, as specifically shown below.

[0100] After the retired lithium cobalt oxide battery was discharged, disassembled, and pulverized, it was dried at 125 °C for 3 hours to obtain 550 g of battery black powder (containing graphite and organic matter). The waste catalyst (W-Mo-Ni / Al2O3) was dried at 110 °C for 3 hours to obtain 450 g of powder (containing waste oil). The battery black powder and the waste catalyst powder were mixed evenly by a mixer at a mass ratio of 1.1:0.9 to obtain a reduced mixed material. In the reduced mixed material, the graphite and organic matter in the battery and the waste oil in the waste catalyst were used as reducing agents and fuels, and additional graphite was added to make the molar ratio of carbon to oxygen in the metal oxide 1.2:1. The total amount of waste oil was 10 wt% of the reduced mixed material.

[0101] In a nitrogen environment containing 2 vol% H2, the reduced mixed material was pre-reduced at 600 °C for 40 minutes, and then heated to 1500 °C at a rate of 10 °C / min and held for 1.5 hours. During the smelting process, an Al2O3-SiO2-CaO-MgO slag conditioner (containing 38 wt% CaO, 32 wt% SiO2, 18 wt% Al2O3, 5 wt% MgO, basicity 1.19) accounting for 20 wt% of the mass of the reduced smelting product was added to control the slag phase.

[0102] After smelting, water quenching at 80 °C was used to separate the alloy from the slag. In the obtained alloy, the recovery rates of Ni, Co, Mo, and W reached 96%, 98%, 96%, and 95% respectively. After water quenching, the slag was acid-leached with 1.5 mol / L HCl solution (solid-liquid ratio 1:10, 85 °C, 2.5 h), and lithium chloride was prepared by concentration and crystallization after filtration, with a lithium recovery rate of 92%.

[0103] Experimental Example 1

[0104] The smelting products of Examples 2 - 7 were subjected to XRF detection.

[0105] Table 1 XRF test results of the smelting products of Examples 2 - 7 (wt%)

[0106]

[0107]

[0108] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0109] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A method for co-smelting and recycling of retired lithium batteries and waste catalysts, characterized in that, It includes the following steps: Raw material pretreatment and batching: Discharge, disassemble, and pulverize the retired lithium batteries to obtain battery black powder, and dry it to obtain battery powder; pulverize and dry the waste catalyst to obtain catalyst powder; mix the battery powder and the catalyst powder to obtain a reduction mixture. Cooperative reduction and high-temperature smelting: Under a protective atmosphere, heat the reduction mixture to carry out a pre-reduction reaction, and then carry out high-temperature smelting to obtain a reduction smelting product. Slag phase regulation and product separation: Add a slag modifier to the reduction smelting product, adjust the basicity of the slag, cool it, and quench it with water to separate the multi-element alloy from the slag, obtaining a multi-element alloy and slag. Acid-leach, filter, concentrate, and precipitate lithium from the slag to obtain lithium salts.

2. The co-smelting recovery method of retired lithium batteries and waste catalysts according to claim 1, wherein In the step of raw material pretreatment and batching, the drying temperature of the battery black powder is 80 - 130 °C, and the drying time is 0.5 - 4 h; the drying temperature of the waste catalyst is 80 - 130 °C, and the drying time is 0.5 - 4 h; the mass ratio of the battery powder to the catalyst powder is (0.5 - 4):

1.

3. The co-smelting recovery method of retired lithium batteries and waste catalysts according to claim 1, wherein In the step of cooperative reduction and high-temperature smelting, the temperature of the pre-reduction reaction is 200 - 800 °C, and the time of the pre-reduction reaction is 10 - 90 min; the high-temperature smelting includes: heating to 1000 - 1800 °C at a rate of 3 - 20 °C / min and holding for 0.3 - 4 h.

4. The co-smelting recovery method of retired lithium batteries and waste catalysts according to claim 1, wherein In the step of slag phase regulation and product separation, the slag modifier includes at least 3 of CaO, SiO2, Al2O3, MgO, and Na2O, and the addition amount of the slag modifier is 10 - 110 wt% of the mass of the reduction smelting product; adjust the basicity of the slag to 0.5 - 2.

0.

5. The co-smelting recovery method of retired lithium batteries and waste catalysts according to claim 4, characterized in that, When the slag modifier includes CaO, SiO2, and Al2O3, the addition amounts of CaO, SiO2, and Al2O3 are 30 - 50 wt%, 30 - 40 wt%, and 1 - 20 wt% of the mass of the reduction smelting product respectively. When the slag modifier includes CaO, SiO2, Al2O3, and MgO, the addition amounts of CaO, SiO2, Al2O3, and MgO are 30 - 45 wt%, 25 - 35 wt%, 1 - 20 wt%, and 3 - 8 wt% of the mass of the reduction smelting product respectively. When the slag modifier includes CaO, SiO2, Al2O3, MgO, and Na2O, the addition amounts of CaO, SiO2, Al2O3, MgO, and Na2O are 29 - 35 wt%, 25 - 35 wt%, 1 - 20 wt%, 3 - 8 wt%, and 1 - 10 wt% of the mass of the reduction smelting product respectively.

6. The co-smelting recovery method of retired lithium batteries and waste catalysts according to claim 1, wherein In the step of slag phase regulation and product separation, the acid leaching includes acid leaching with sulfuric acid or hydrochloric acid, the solid-liquid ratio of the acid leaching is 1:(5 - 10), the temperature is 60 - 90 °C, and the time is 1 - 3 h.

7. The method for co-smelting and recycling of retired lithium batteries and waste catalysts according to any one of claims 1-6, characterized in that, It also includes adding an auxiliary carbon source after raw material pretreatment and batching, and the auxiliary carbon source includes graphite or waste oil. When the auxiliary carbon source includes graphite, the molar ratio of carbon to oxygen in the metal oxide in the reduction mixture after adding graphite is (0.8 - 2.0):

1. When the auxiliary carbon source includes waste oil, the addition amount of the waste oil is 2-25 wt% of the mass of the reduction mixture.

8. Application of the method for co-smelting and recycling of waste lithium batteries combined with waste catalysts according to any one of claims 1-7 in the preparation of multi-element alloys.

9. Application of the method for co-smelting and recycling of waste lithium batteries combined with waste catalysts according to any one of claims 1-7 in the recovery of lithium salts.

10. A method for preparing a multi-component alloy and / or a lithium salt, characterized in that, The waste lithium batteries are treated by using the method for co-smelting and recycling of waste lithium batteries combined with waste catalysts according to any one of claims 1-7.

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