DRT-based method for efficiently recovering lithium from retired battery powder, and application thereof

Abstract

The present invention relates to the technical field of retired battery recycling, and to a DRT-based method for efficiently recovering lithium from retired battery powder, and an application thereof. The method comprises: mixing retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions, and carrying out reduction roasting to form reduced battery powder containing a perovskite-type oxide ABO3; mixing the reduced battery powder with water, and introducing carbon dioxide for carbonization leaching, to obtain a leachate material; carrying out solid-liquid separation on the leachate material, wherein the filtrate contains lithium bicarbonate; and carrying out impurity removal and pyrolysis on the filtrate to obtain battery-grade lithium carbonate. According to the present invention, synthesis of a perovskite-type oxide during reduction of battery powder is coupled and coordinated with carbonization leaching, so that carbon dioxide can be fixed, making the carbonization reaction more complete, and reducing the leaching of nickel, cobalt and manganese metals to obtain a pure lithium solution; subsequently, only simple impurity removal is required to obtain battery-grade lithium carbonate by pyrolysis.

Description

A DRT-based method for efficiently recovering lithium from retired battery powder and its application Technical Field

[0001] The present disclosure relates to the technical field of retired battery recycling, and in particular to a method for efficiently recovering lithium from retired battery powder based on DRT and its application. Background Art

[0002] The rapid development of new energy electric vehicles has led to a growing demand for lithium carbonate and lithium hydroxide, the raw materials for lithium batteries. This has accelerated the development of lithium resource extraction and recovery. However, the uneven distribution of lithium resources worldwide and the limited availability of recoverable reserves have led to widespread attention for lithium recovery, with the recycling of retired lithium-ion batteries being a key focus.

[0003] Recycling of retired lithium-ion batteries is primarily divided into two main methods: pyrometallurgy and hydrometallurgy. Pyrometallurgy directly uses high-temperature treatment to extract the metal or metal oxide from the electrode. Hydrometallurgy involves disassembling the battery casing, crushing, and screening it to obtain the electrode material. The positive electrode powder is then leached with acid, with the metal entering the leachate as ions. The valuable metals are then separated individually through precipitation separation, solvent extraction, electrodeposition, and ion exchange, resulting in single metal products or metal compounds.

[0004] Chinese patent application CN106129511A uses a carbon-containing reducing agent such as one or a mixture of lignite, bituminous coal and anthracite to mix with lithium-ion battery positive electrode materials, and performs reduction roasting at high temperature. The roasted product is immersed in water and CO2 is introduced to carbonize to obtain a LiHCO3 solution. However, the lithium extraction rate obtained by this method is only 90%-91%.

[0005] Chinese patent application CN111206154A separates nickel, cobalt, manganese and lithium from the leachate through an extraction process. The leachate of waste ternary battery materials is used as raw material. The leachate contains metal ions such as nickel, cobalt, manganese and lithium. A new extraction system is used to selectively extract and separate nickel, cobalt, manganese and lithium valuable metals in sequence. Lithium is recovered in the final tail liquid. During the pretreatment process, a lot of lithium will be lost as nickel, cobalt and manganese are removed, which is not conducive to the resource utilization of lithium.

[0006] In summary, the current treatment of retired lithium-ion batteries and the post-processing and impurity removal of leachates have many shortcomings. Therefore, it is urgent to develop a method for extracting lithium from retired lithium-ion batteries with low energy consumption, simple process, and high efficiency.

[0007] In view of this, the present disclosure is proposed.

[0008] Summary of the Invention

[0009] The purpose of the present disclosure is to provide a method for efficiently recovering lithium from retired battery powder based on DRT and its application.

[0010] The present disclosure is achieved as follows:

[0011] In a first aspect, the present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising: mixing retired battery powder, a carbon reducing agent, and an A-site reaction material containing rare earth ions or alkaline earth ions, and performing reduction roasting to form reduced battery powder containing perovskite-type oxide ABO3;

[0012] Carrying out carbonization leaching of the reduced battery powder with carbon dioxide in an aqueous solution to obtain a leached material;

[0013] The leached material is subjected to solid-liquid separation, and the filtrate is subjected to impurity removal and pyrolysis to obtain battery-grade lithium carbonate.

[0014] In an optional embodiment, the A-site reactant includes a combination of one or more of rare earth oxides, rare earth nitrates, alkaline earth metal oxides, and alkaline earth metal nitrates.

[0015] In an optional embodiment, the rare earths in the rare earth oxide and the rare earth nitrate are independently selected from one or more combinations of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium.

[0016] In an optional embodiment, the alkaline earth metals in the alkaline earth metal oxide and the alkaline earth metal nitrate are independently selected from a combination of one or more of beryllium, magnesium, calcium, strontium, barium and radium.

[0017] In an optional embodiment, the A-site reaction material includes a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide and calcium nitrate.

[0018] In an optional embodiment, the contents of nickel, cobalt and manganese in the retired battery powder are detected, and the molar ratio of the A-site reaction material to the total content of nickel, cobalt and manganese in the retired battery powder is 0.5-1:0.5-1.

[0019] In an optional embodiment, the amount of the carbon reducing agent is 10%-50% of the mass of the retired battery powder.

[0020] In an alternative embodiment, the carbon reducing agent comprises a combination of one or more of inorganic carbon and organic carbon.

[0021] In an optional embodiment, the inorganic carbon includes one or more combinations of graphite, carbon black, carbon monoxide, lignite, bituminous coal and anthracite.

[0022] In an optional embodiment, the organic carbon includes a combination of one or more of sawdust, glucose, semi-coke, chemical coke and metallurgical coke.

[0023] In an optional embodiment, the retired battery powder includes lithium batteries containing at least one element of nickel, cobalt, and manganese.

[0024] In an optional embodiment, the retired battery powder includes any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium battery and nickel-cobalt-manganese ternary lithium battery.

[0025] In an optional embodiment, the reduction roasting temperature is 900-1200° C., and the roasting time is 2-8 hours.

[0026] In an optional embodiment, the reduction roasting temperature is 1100-1200° C., and the roasting time is 2-4 hours.

[0027] In an optional embodiment, the solid-liquid ratio of the reduced battery powder to the water is 1:3-10.

[0028] In an optional embodiment, the inlet flow rate of carbon dioxide is 0.1 L / min-5 L / min.

[0029] In an optional embodiment, the carbonization leaching time is 1-3 hours.

[0030] In an optional embodiment, the impurity removal includes refining and removing impurities from the filtrate using a resin.

[0031] In an optional embodiment, the resin is at least one of an aminocarboxylic acid chelate resin and an aminophosphoric acid chelate resin.

[0032] In an optional embodiment, the resin includes any one of CH-90Na chelating resin, Lx92, D402 and LS500.

[0033] In an optional embodiment, the pyrolysis temperature is 60-95° C., and the pyrolysis time is 1-5 h.

[0034] In a second aspect, the present disclosure provides the application of the DRT-based method for efficiently recovering lithium from retired battery powder as described in the aforementioned embodiment in the recovery of retired lithium-ion batteries.

[0035] The present disclosure has the following beneficial effects:

[0036] The present disclosure provides a DRT-based method for efficiently recovering lithium from retired battery powder. The method comprises reducing and roasting retired battery powder, a carbon reducing agent, and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt, and manganese are precipitated as oxides or metal elements. The precipitated transition metal oxides then react with the A-site reaction material under high-temperature roasting to form a perovskite-type oxide (ABO3). The perovskite-type oxide is mixed with the lithium carbonate to form a solid-phase reduced battery powder. The reduced battery powder is then carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite-type oxide can fix carbon dioxide, making the carbonization reaction more complete. In addition, the perovskite-type oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements during the carbonization process after adding water and introducing carbon dioxide, thereby reducing the leaching of nickel, cobalt, and manganese metals, thereby obtaining a relatively pure lithium bicarbonate solution. The lithium bicarbonate only needs to be simply removed from the lithium bicarbonate to be thermally decomposed to obtain battery-grade lithium carbonate. This disclosure utilizes perovskite-type oxides synthesized by reducing battery powder, coupled with carbonization leaching, to provide a novel process for highly selective lithium extraction, effectively facilitating lithium recovery from retired lithium-ion batteries. The DRT-based method for efficiently recovering lithium from retired battery powder can be widely applied to the recycling of retired lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0038] FIG1 is a process flow chart of a method for efficiently recovering lithium from retired battery powder based on DRT provided in the present disclosure. DETAILED DESCRIPTION

[0039] The embodiments of the present disclosure will be described in detail below with reference to the examples. However, those skilled in the art will appreciate that the following examples are intended only to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. Where specific conditions are not specified in the examples, the experiments were performed under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0040] The endpoints of the ranges and any values ​​disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0041] Directional Recycling Technology (DRT) is a technology based on reverse product positioning design. It uses short-range recycling processes to recycle spent materials from retired products into usable materials for production. In the field of power batteries, directed recycling refers to the process of converting used batteries into the materials needed for power battery manufacturing through pre-treatment, hydrometallurgy, and other processes. Manufacturers can directly use the processed battery raw materials to produce high-quality power batteries.

[0042] Based on the above design ideas, the present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT, as shown in Figure 1, which includes the following steps:

[0043] S1. Prepare ingredients.

[0044] (1) Retired battery powder:

[0045] Retired battery powder includes lithium batteries containing at least one of nickel, cobalt, and manganese. Specifically, retired battery powder includes, but is not limited to, any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium batteries, and nickel-cobalt-manganese ternary lithium batteries.

[0046] (2) Carbon reducing agent:

[0047] Carbon reductants include one or more combinations of inorganic carbon and organic carbon. Inorganic carbon includes, but is not limited to, one or more combinations of graphite, carbon black, carbon monoxide, lignite, bituminous coal, and anthracite. Organic carbon includes, but is not limited to, one or more combinations of sawdust, glucose, semi-coke, chemical coke, and metallurgical coke.

[0048] (3) A-site reaction materials containing rare earth ions or alkaline earth ions:

[0049] The A-site reactant comprises a combination of one or more of rare earth oxides, rare earth nitrates, alkaline earth metal oxides, and alkaline earth metal nitrates. The rare earths in the rare earth oxides and rare earth nitrates are independently selected from a combination of one or more of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium. The alkaline earth metals in the alkaline earth metal oxides and alkaline earth metal nitrates are independently selected from a combination of one or more of beryllium, magnesium, calcium, strontium, barium, and radium.

[0050] Specifically, in some embodiments of the present disclosure, the A-site reactant may include, for example, a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide, and calcium nitrate.

[0051] S2. Reduction roasting.

[0052] Retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions are mixed and reduction roasted to form reduced battery powder containing perovskite-type oxide ABO3.

[0053] The nickel, cobalt, and manganese contents of the retired battery powder were tested, and the molar ratio of the A-site reaction material to the total nickel, cobalt, and manganese contents of the retired battery powder was 0.5-1:0.5-1. The carbon reducing agent was used in an amount of 10%-50% of the mass of the retired battery powder.

[0054] During the reduction process, nickel, cobalt and manganese are first precipitated as oxides or metal elements, and lithium is precipitated as lithium carbonate. The precipitated transition metal oxides react with the A-site reaction material to form perovskite-type oxides (ABO3) under high-temperature calcination.

[0055] The process equation is as follows (taking lanthanum nitrate as an example):

[0056] 1)Li(Ni x Co y Mn 1-x-y )O2+(1+2x+2y) / 4C=1 / 2Li2O+xNi+yCo+(1-xy)MnO+(1+2x+2y) / 4CO2;

[0057] 2) Li2O+CO2=Li2CO3;

[0058] 3)La(NO3)3·6H2O+Ni / Co / MnO→La(Ni / Co / Mn)O3.

[0059] In the present disclosure, the reduction roasting temperature is 900-1200°C, and the roasting time is 2-8 hours. In some embodiments, the reduction roasting temperature can be, for example, any one of 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, and 1200°C, or a range between any two thereof, and the roasting time can be, for example, any one of 2h, 3h, 4h, 5h, 6h, 7h, and 8h, or a range between any two thereof. Since the perovskite oxide ABO3 needs to be formed in this application, it is further preferred that the reduction roasting temperature is 1100-1200°C, and the roasting time is 2-4h.

[0060] S3, carbonization leaching.

[0061] The reduced battery powder is mixed with water at a solid-liquid ratio of 1:3-10, and carbon dioxide is introduced for carbonization leaching at a flow rate of 0.1 L / min-5 L / min. The carbonization leaching time is 1-3 hours to obtain a leached material.

[0062] Since the reduction battery powder contains perovskite-type oxide ABO3, which is an alkaline oxide, it has a strong ability to capture carbon dioxide and can promote the continuous occurrence of carbonization reaction.

[0063] The main equation is: Li2CO3+H2O+CO2=2LiHCO3.

[0064] S4. Post-processing.

[0065] After carbonization leaching is complete, the leachate is separated into solids and liquids. The filtrate is primarily lithium bicarbonate, with only a small amount of nickel, cobalt, and manganese leached out. The solids consist of perovskite-type oxides and nickel, cobalt, and manganese slag. After simple impurity removal, the liquid can be pyrolyzed to produce battery-grade lithium carbonate.

[0066] The impurity removal includes refining and removing the lithium bicarbonate with a resin. The resin is any one of an aminocarboxylic acid chelate resin and an aminophosphoric acid chelate resin, including any one of CH-90Na chelate resin, Lx92, D402, and LS500. Lx92, D402, and LS500 were purchased from Xi'an Lanxiao Technology New Materials Co., Ltd., Jiangyin Suqing Resin Co., Ltd., and Xi'an Lanshen New Materials Technology Co., Ltd., respectively, and are product names of the companies.

[0067] The pyrolysis temperature is 60-95°C, and the pyrolysis time is 1-5h.

[0068] The main equation for pyrolysis is: 2LiHCO3=Li2CO3+H2O+CO2↑.

[0069] The present disclosure provides a DRT-based method for efficiently recovering lithium from retired battery powder. The method comprises reducing and roasting retired battery powder, a carbon reducing agent, and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt, and manganese are precipitated as oxides or metal elements. The precipitated transition metal oxides then react with the A-site reaction material under high-temperature roasting to form a perovskite-type oxide (ABO3). The perovskite-type oxide is mixed with the lithium carbonate to form a solid-phase reduced battery powder. The reduced battery powder is then carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite-type oxide can fix carbon dioxide, making the carbonization reaction more complete. In addition, the perovskite-type oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements during the carbonization process after adding water and introducing carbon dioxide, thereby reducing the leaching of nickel, cobalt, and manganese metals, thereby obtaining a relatively pure lithium bicarbonate solution. The lithium bicarbonate only needs to be simply removed from the lithium bicarbonate to be thermally decomposed to obtain battery-grade lithium carbonate. This disclosure utilizes perovskite-type oxides synthesized by reducing battery powder, coupled with carbonization leaching, to provide a novel process for highly selective lithium extraction, effectively facilitating lithium recovery from retired lithium-ion batteries. The DRT-based method for efficiently recovering lithium from retired battery powder can be widely applied to the recycling of retired lithium-ion batteries.

[0070] The features and performance of the present disclosure are further described in detail below with reference to the embodiments.

[0071] Example 1

[0072] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0073] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 709g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), with the perovskite A:B ratio being 0.5:1 (mol). The temperature was raised to 1000°C for 3 hours, during which nickel, cobalt, and manganese precipitated as oxides or metal elements. Some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was then mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was decontaminated with CH-90Na chelating resin before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0074] Example 2

[0075] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0076] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 1419g of lanthanum nitrate hexahydrate powder and 20% carbon reducing agent (graphite), with the perovskite A:B ratio being 1:1 (mol). The temperature was raised to 1000°C for 3 hours. Nickel, cobalt, and manganese precipitated as oxides or metal elements, and some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0077] Example 3

[0078] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0079] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 2838g of lanthanum nitrate hexahydrate powder and 30% carbon reducing agent (graphite), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1000°C for 3 hours, during which nickel, cobalt, and manganese precipitated as oxides or metal elements. Some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0080] Example 4

[0081] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0082] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 2838g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1100°C for 3 hours, during which nickel, cobalt, and manganese precipitated as oxides or metal elements. Some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0083] Example 5

[0084] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0085] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 2838g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1200°C for 3 hours, during which nickel, cobalt, and manganese precipitated as oxides or metal elements. Some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0086] Example 6

[0087] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0088] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 2118g of cerium nitrate powder and 50% carbon reducing agent (wood chips), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1200°C for 2 hours. Nickel, cobalt, and manganese precipitated as oxides or metal elements, and some of the nickel, cobalt, and manganese oxides combined with cerium nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was then mixed with water at a liquid-to-solid ratio of 3:1, and carbon dioxide was introduced at 2L / min for 3 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 60°C for 3 hours to produce battery-grade lithium carbonate.

[0089] Example 7

[0090] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0091] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 364g of calcium oxide powder and 40% carbon reducing agent (glucose), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1200°C for 4 hours, during which nickel, cobalt, and manganese precipitated as oxides or metal elements. Some of the nickel, cobalt, and manganese oxides combined with calcium oxide to form perovskite-type oxides, and lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 10:1, and 3L / min of carbon dioxide was introduced for carbonization and leaching for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 90°C for 4 hours to produce battery-grade lithium carbonate.

[0092] Example 8

[0093] This embodiment provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0094] 600g of retired lithium-ion battery powder (Li: 6.51%, Co: 55.28%) was thoroughly mixed with 4918g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent (graphite), with the perovskite A:B ratio being 1:0.5 (mol). The temperature was raised to 1200°C for 3 hours. Nickel, cobalt, and manganese precipitated as oxides or metal elements, and some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and 1L / min of carbon dioxide was introduced for carbonization and leaching for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities and then pyrolyzed at 85°C for 2 hours to obtain battery-grade lithium carbonate.

[0095] Comparative Example 1

[0096] This comparative example provides a method for efficiently recovering lithium from retired battery powder based on DRT, comprising the following specific steps:

[0097] Take 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) and 10% carbon reducing agent, mix them thoroughly, place them in a reaction pipe, raise the temperature to 650℃, and last for 3 hours. Nickel, cobalt and manganese are precipitated as oxides or metal elements, and lithium is precipitated as lithium carbonate. The powder is mixed with water at a liquid-solid ratio of 7:1, and 1L / min of carbon dioxide is introduced for carbonization and leaching for 2 hours. The resulting liquid-solid mixture is filtered, and the filtrate is removed by chemical precipitation and resin, and then pyrolyzed at 85℃ for 2 hours to obtain lithium carbonate.

[0098] Comparative Example 2

[0099] This comparative example provides a method for efficiently recovering lithium from retired battery powder based on DRT, which is basically the same as Example 1, except that the amount of lanthanum nitrate hexahydrate powder is different. Specifically, it includes the following specific steps:

[0100] 600g of retired lithium-ion battery powder (Li: 4.10%, Ni: 22.15%, Co: 3.35%, Mn: 5.88%) was thoroughly mixed with 283g of lanthanum nitrate hexahydrate powder and 10% carbon reducing agent, with the perovskite A:B ratio being 0.2:1 (mol). The temperature was raised to 1000°C for 3 hours. Nickel, cobalt, and manganese precipitated as oxides or metal elements, and some of the nickel, cobalt, and manganese oxides combined with lanthanum nitrate to form perovskite-type oxides, while lithium precipitated as lithium carbonate. The powder was mixed with water at a liquid-to-solid ratio of 7:1, and carbon dioxide was introduced at 1L / min for 2 hours. The resulting liquid-solid mixture was filtered, and the filtrate was treated with resin to remove impurities before being pyrolyzed at 85°C for 2 hours to produce battery-grade lithium carbonate.

[0101] Experimental example

[0102] The Li content of the leachate in Examples 1-7 and Comparative Examples 1-3 was tested, and the Li leaching rate was calculated, wherein Li leaching rate (%) = C t *V t / (w t *m0)*100; where C t and V t are the lithium concentration (g / L) and liquid volume in the leachate, respectively. The liquid volume is equal to the mass of the battery powder multiplied by the solid-liquid ratio, w t and m0 are the lithium mass fraction and the mass of the battery powder, respectively. The statistical results are shown in Table 1.

[0103] Table 1 Process data of lithium recovery from retired lithium-ion batteries

[0104] As can be seen from the above table, Examples 1-8 of the present application can all obtain better leaching rates, especially when the perovskite A:B position = 1:0.5, the Li leaching rate reaches more than 98%, which is significantly better than the leaching rate of Comparative Example 1 without adding the A-site reactant. As can be seen from Comparative Example 2, when the amount of A-site reactant added is too small, less perovskite-type oxide is generated, and its ability to capture carbon dioxide is weak, so the leaching rate is also significantly lower than that of Example 1.

[0105] In summary, the present disclosure provides a method for efficiently recovering lithium from retired battery powder based on DRT. The method uses retired battery powder, a carbon reducing agent, and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials for reduction roasting. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt, and manganese are precipitated as oxides or metal elements. The precipitated transition metal oxides and the A-site reaction material are then roasted at high temperature to form a perovskite-type oxide (ABO3). The perovskite-type oxide is mixed with the lithium carbonate to form a solid phase of reduced battery powder. The reduced battery powder is then carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite-type oxide can fix carbon dioxide, making the carbonization reaction more complete. In addition, the perovskite-type oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements during the carbonization process after adding water and introducing carbon dioxide, and further reduce the leaching of nickel, cobalt, and manganese metals, thereby obtaining a relatively pure lithium bicarbonate solution. Subsequently, the lithium bicarbonate only needs to be simply impurity-removed to obtain battery-grade lithium carbonate by thermal decomposition. This disclosure utilizes perovskite-type oxides synthesized by reducing battery powder, coupled with carbonization leaching, to provide a novel process for highly selective lithium extraction, effectively facilitating lithium recovery from retired lithium-ion batteries. The DRT-based method for efficiently recovering lithium from retired battery powder can be widely applied to the recycling of retired lithium-ion batteries.

[0106] The above describes in detail the optional embodiments of the present disclosure, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, various simple variations of the technical solution of the present disclosure can be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present disclosure and fall within the scope of protection of the present disclosure. Industrial Applicability

[0107] The present disclosure provides a DRT-based method for efficiently recovering lithium from retired battery powder. The method comprises reducing and calcining retired battery powder, a carbon reducing agent, and an A-site reaction material containing rare earth ions or alkaline earth ions as raw materials. During the reduction process, lithium is precipitated in the form of lithium carbonate, and nickel, cobalt, and manganese are precipitated as oxides or metal elements. The precipitated transition metal oxides then react with the A-site reaction material under high-temperature calcination to form a perovskite-type oxide (ABO3). The perovskite-type oxide is mixed with the lithium carbonate to form a solid-phase reduced battery powder. The reduced battery powder is then carbonized by adding water. The lithium carbonate reacts with carbonic acid to form lithium bicarbonate. The perovskite-type oxide can fix carbon dioxide, making the carbonization reaction more complete. In addition, the perovskite-type oxide has a relatively stable structure, which can reduce the dissolution of heavy metal elements during the carbonization process after adding water and introducing carbon dioxide, and further reduce the leaching of nickel, cobalt, and manganese metals, thereby obtaining a relatively pure lithium bicarbonate solution. Subsequently, the lithium bicarbonate only needs to be simply removed for thermal decomposition to obtain battery-grade lithium carbonate. This disclosure utilizes perovskite-type oxides synthesized by reducing battery powder, coupled with carbonization leaching, to provide a novel process for highly selective lithium extraction, effectively facilitating lithium recovery from retired lithium-ion batteries. The DRT-based method for efficiently recovering lithium from retired battery powder can be widely applied to the recycling of retired lithium-ion batteries.

Claims

1. A method for efficiently recovering lithium from retired battery powder based on DRT, characterized in that: The method comprises: mixing retired battery powder, a carbon reducing agent and an A-site reaction material containing rare earth ions or alkaline earth ions, and performing reduction roasting to form reduced battery powder containing perovskite-type oxide ABO3; Carrying out carbonization leaching of the reduced battery powder with carbon dioxide in an aqueous solution to obtain a leached material; The leached material is subjected to solid-liquid separation, and the filtrate is subjected to impurity removal and pyrolysis to obtain battery-grade lithium carbonate.

2. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 1, characterized in that: The A-site reaction material includes a combination of one or more of rare earth oxides, rare earth nitrates, alkaline earth metal oxides and alkaline earth metal nitrates.

3. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 2, characterized in that: The rare earths in the rare earth oxides and the rare earth nitrates are independently selected from one or more combinations of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium.

4. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 2 to 3, characterized in that: The alkaline earth metals in the alkaline earth metal oxides and alkaline earth metal nitrates are independently selected from one or more combinations of beryllium, magnesium, calcium, strontium, barium and radium.

5. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 4, characterized in that: The A-site reaction material includes a combination of one or more of lanthanum oxide, lanthanum nitrate, cerium oxide, cerium nitrate, calcium oxide and calcium nitrate.

6. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 5, characterized in that: The contents of nickel, cobalt and manganese in the retired battery powder are detected, and the molar ratio of the A-site reaction material to the total content of nickel, cobalt and manganese in the retired battery powder is 0.5-1:0.5-1.

7. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 6, characterized in that: The amount of the carbon reducing agent used is 10%-50% of the mass of the retired battery powder.

8. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 7, characterized in that: The carbon reducing agent includes a combination of one or more of inorganic carbon and organic carbon.

9. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 8, characterized in that: The inorganic carbon includes one or more of graphite, carbon black, carbon monoxide, lignite, bituminous coal and anthracite.

10. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 8 to 9, characterized in that: The organic carbon includes one or more combinations of sawdust, glucose, semi-coke, chemical coke and metallurgical coke.

11. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 10, characterized in that: The retired battery powder includes lithium batteries containing at least one element of nickel, cobalt and manganese.

12. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 11, characterized in that: The retired battery powder includes any one or more of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, nickel-cobalt binary lithium battery and nickel-cobalt-manganese ternary lithium battery.

13. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 12, characterized in that: The reduction roasting temperature is 900-1200° C., and the roasting time is 2-8 hours.

14. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 13, characterized in that: The reduction roasting temperature is 1100-1200° C., and the roasting time is 2-4 hours.

15. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 14, characterized in that: The solid-to-liquid ratio of the reduced battery powder to the water is 1:3-10.

16. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 15, characterized in that: The inlet flow rate of the carbon dioxide is 0.1L / min-5L / min.

17. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 16, characterized in that: The carbonization leaching time is 1-3h.

18. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 17, characterized in that: The impurity removal includes refining and removing impurities from the filtrate using resin.

19. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 18, characterized in that: The resin is at least one of an aminocarboxylic acid chelating resin and an aminophosphoric acid chelating resin.

20. The method for efficiently recovering lithium from retired battery powder based on DRT according to claim 18, characterized in that: The resin includes any one of CH-90Na chelating resin, Lx92, D402 and LS500.

21. The method for efficiently recovering lithium from retired battery powder based on DRT according to any one of claims 1 to 20, characterized in that: The pyrolysis temperature is 60-95° C., and the pyrolysis time is 1-5 hours.

22. Application of the method for efficiently recovering lithium from retired battery powder based on DRT as described in any one of claims 1 to 21 in the recovery of retired lithium-ion batteries.

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