Methods, equipment and applications for high-temperature chlorination roasting of spent lithium batteries

Abstract

This invention provides a method, apparatus, and application for high-temperature chlorination roasting of spent lithium batteries, relating to the field of lithium battery recycling technology. The method includes roasting spent lithium battery materials under a chlorine atmosphere, dissolving the roasted reactants in water to obtain a first solution, and recovering metals from the first solution. This method employs high-temperature chlorination roasting to convert valuable metals in the spent lithium battery materials into metal chlorides. The reactants are then dissolved in water. Since only metals react with chlorine to form soluble metal chlorides, the metal chlorides are dissolved in water according to their different solubilities, allowing the valuable metals in the spent lithium battery materials to be recycled. This method avoids the use of reducing agents, does not generate large amounts of leachate, is environmentally friendly, and achieves a high recovery rate of valuable metals.

Description

Technical Field

[0001] This invention relates to the field of lithium battery recycling technology, and more specifically, to a method, equipment, and application for high-temperature chlorination roasting of waste lithium batteries. Background Technology

[0002] With the rapid increase in electronic product consumption, the number of discarded lithium-ion batteries has increased dramatically. High-cobalt cathode materials possess advantages such as high charging cut-off voltage and high compaction density, while also maintaining a stable material structure, making them crucial in the consumer electronics field. Lithium cobalt oxide used in mobile phones is a prime example. Discarded lithium-ion batteries contain not only valuable metals such as lithium, nickel, cobalt, manganese, copper, and aluminum, but also toxic electrolytes such as ethylene carbonate, propylene carbonate, and lithium hexafluorophosphate, as well as binders. Improper disposal of discarded lithium-ion batteries not only wastes metal resources but can also cause serious environmental damage.

[0003] Currently, the main methods for treating waste lithium-ion batteries include hydrometallurgy and reduction roasting. Hydrometallurgy is a traditional method for recovering valuable metals from waste lithium-ion batteries, primarily involving disassembly and crushing to obtain cathode powder containing most of the valuable metals. However, due to the binder, the cathode material is tightly bonded to the electrode, so oxidative acid leaching is often required for extraction. This requires a certain reaction apparatus and the addition of a reducing agent during the reaction. Maintaining a certain solid content during stirring is necessary to meet the kinetic conditions required for the chemical reaction, resulting in a large amount of leachate and requiring extensive equipment. Reduction roasting uses coke powder and coal powder, which, after reduction, produce ash that typically accounts for 10-20% of the total weight. The decomposition of PVDF and incomplete combustion of carbon during roasting generate large amounts of polluting gases, making treatment complex.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method, equipment, and application for high-temperature chlorination roasting of waste lithium batteries, which can convert valuable metals in waste lithium battery materials into metal chlorides for recycling. This avoids the use of reducing agents, does not generate a large amount of leachate, is environmentally friendly, and has a high recovery rate of valuable metals.

[0006] The embodiments of the present invention are implemented as follows:

[0007] In a first aspect, the present invention provides a method for high-temperature chlorination roasting of waste lithium batteries, comprising roasting the waste lithium battery material under a chlorine atmosphere, dissolving the roasted reactants in water to obtain a first solution, and recovering metals from the first solution.

[0008] Currently, the main methods for recycling valuable metals from spent lithium batteries include hydrometallurgical techniques and reduction roasting. Hydrometallurgical techniques suffer from drawbacks such as the need for reducing agents, large leaching volumes, organic acid leaching leading to cathode material contamination, and low cathode reduction rates in pyrolysis separation. Reduction roasting methods, on the other hand, are hampered by high reduction temperatures, high energy consumption, and the generation of difficult-to-treat polluting gases. Therefore, a new method for recycling valuable metals from spent lithium batteries is urgently needed. The inventors discovered that a high-temperature chlorination roasting method converts valuable metals from spent lithium battery materials into metal chlorides. The reactants are then dissolved in water. Since only the metals react with chlorine gas to form soluble metal chlorides, these chlorides are dissolved in water based on their solubility, allowing the valuable metals from the spent lithium battery materials to be recycled. This method avoids the use of reducing agents, does not generate large amounts of leaching liquid, is environmentally friendly, and achieves a high recovery rate of valuable metals.

[0009] Through long-term research, the inventors discovered that the main metal elements contained in waste lithium batteries include nickel, cobalt, lithium, and manganese. The metal chlorides formed by the above metal elements after high-temperature roasting with chlorine are all soluble salts. Therefore, the difference in solubility of the products can be used to convert the metal elements in waste lithium batteries into metal chlorides, thereby recycling the valuable metals in waste lithium batteries.

[0010] When the main metal elements in spent lithium batteries undergo high-temperature chlorination roasting, the following reaction process occurs:

[0011] 6LiCoO2+3Cl2(g)——6LiCl+2Co3O4+2O2(g);

[0012] 2Co3O4+3Cl2(g)——6CoCl+4O2(g);

[0013] 2LiNiO2+3Cl2(g)——2NiCl2+2LiCl+2O2(g);

[0014] 2LiMn2O4+Cl2(g)——2LiCl+2Mn2O3+O2(g);

[0015] 2Mn2O3+4Cl2(g)——4MnCl2+3O2(g).

[0016] As can be seen from the above reaction equation, all the major metal elements in waste lithium batteries can generate metal chloride salts after high-temperature chlorination roasting. Therefore, the differences in solubility of the components in waste lithium batteries can be used to separate metals from other impurities.

[0017] In some embodiments of the present invention, since the non-metallic components in the waste lithium battery materials do not react with chlorine gas and are insoluble in water, when the calcined solid material is added to an aqueous solution, the non-metallic components remain in the water in solid form, while the metal salts generated by the calcination reaction dissolve. The aqueous solution is then subjected to solid-liquid separation, and the collected liquid is the first solution.

[0018] In an optional implementation, the waste lithium battery materials are roasted in a closed environment by introducing a chlorine atmosphere.

[0019] Preferably, the chlorine atmosphere includes chlorine and a protective gas. The protective gas is added to the chlorine atmosphere for safety reasons during the reaction process. Furthermore, using large amounts of high-purity chlorine not only leads to waste but also raises environmental concerns due to emissions.

[0020] Furthermore, the high-temperature chlorine roasting process of the present invention is not a rapid reaction process. It is necessary to ensure that the waste lithium battery materials remain in contact with the high-temperature chlorine gas for a certain period of time. Therefore, in order to ensure the smooth progress of the reaction and avoid reaction accidents, a protective gas should be added to the chlorine atmosphere.

[0021] Preferably, the protective gas is an inert gas, including at least one of nitrogen, helium, or argon.

[0022] Preferably, the chlorine atmosphere is a mixture of chlorine and nitrogen.

[0023] Preferably, the volume ratio of chlorine to nitrogen is 1 to 3:1, more preferably 2 to 3:1. Controlling the ratio of nitrogen to chlorine within the above range not only ensures the utilization rate of chlorine in the reaction and avoids waste of chlorine, but also ensures the safety of the reaction process.

[0024] In an optional embodiment, the chlorine atmosphere is replenished to the closed environment of the roasting process. The chlorine atmosphere is replenished once every 5 to 10 minutes, and the chlorine atmosphere replenished each time accounts for 1 to 2% of the volume of the closed environment.

[0025] In an optional embodiment, the calcination temperature is 550–850°C and the calcination time is 60–120 min.

[0026] Preferably, the roasting temperature is 750–850℃ and the roasting time is 90–120 min.

[0027] More preferably, the roasting temperature is 850℃ and the roasting time is 90min.

[0028] In an optional embodiment, the waste lithium battery material is further preheated before roasting, the preheating temperature being the same as the roasting temperature, and the preheating process being conducted in an oxygen-free environment.

[0029] Because oxygen reacts with electrolytes and other substances at high temperatures to produce a large amount of gas, an oxygen-free environment is required during preheating to prevent the gas from being trapped and affecting the recycling of waste lithium battery materials. In an optional embodiment, the gas volatilized during roasting is absorbed by passing it into water to obtain a second solution. Since the roasting process involves high temperatures and chlorine readily volatilizes, carrying trace amounts of metal, using an aqueous solution to absorb the gas can recover these small amounts of metal while simultaneously absorbing the chlorine, thus preventing environmental pollution caused by direct chlorine emissions.

[0030] Metal recovery involves mixing the first and second solutions and then drying them together. Since both the first and second solutions are chloride solutions containing metals, the water in both solutions evaporates after drying, allowing the metal elements in the spent lithium batteries to be recovered.

[0031] Preferably, the drying temperature is 70–90°C and the drying time is 20–30 h.

[0032] In other embodiments, the first and second solutions may be processed as needed to recover the metal components in other forms.

[0033] In an optional embodiment, the method for preparing waste lithium battery materials includes: leaching waste lithium batteries in nitric acid solution, drying them, and crushing them into granules.

[0034] Preferably, in order to avoid leaching of metal elements and remove material adhering to the electrode, the mass fraction of the nitric acid solution is 8-10%, and the leaching time is 3-5 minutes.

[0035] Preferably, the drying temperature is 60–80°C and the drying time is 5–6 hours.

[0036] Preferably, before leaching, the waste lithium batteries are further subjected to sequential discharge treatment, cleaning, drying, crushing and disassembly.

[0037] Preferably, the discharge treatment includes placing the waste lithium battery in a NaCl solution with a mass fraction of 10-15%.

[0038] Preferably, the waste lithium battery material comprises, by mass ratio, Ni: 1-2%, Co: 50-55%, Li: 7-8%, Mn: 7-8%, and C: 0.1-1%, and the particle size of the waste lithium battery material is less than 1 mm.

[0039] More preferably, the waste lithium battery material comprises, by mass ratio: Ni: 1.42%, Co: 51.52%, Li: 7.21%, Mn: 7.34%, and C: 0.77%.

[0040] In other embodiments, the composition and proportion of metal elements in waste lithium battery materials can be changed according to different raw materials.

[0041] Secondly, the present invention provides a device for high-temperature chlorination roasting of waste lithium batteries, applicable to the method of any of the foregoing embodiments, including a chlorine reaction chamber, a water immersion vessel, and a first solution collection chamber.

[0042] The chlorine reaction chamber includes a chlorine atmosphere inlet, a waste lithium battery material inlet, and a reactant outlet. The reactant outlet is connected to the water immersion kettle via a pipe, and a first valve is installed on the pipe at the connection point. The water immersion kettle is connected to the first solution collection chamber via a pipe, and a second valve is installed on the pipe at the connection point, so that the products generated by the reaction of waste lithium battery materials and chlorine enter the water immersion kettle for treatment and then flow into the first solution collection chamber.

[0043] The chlorine reaction chamber is also equipped with a primary stirring device and an automatic heating device.

[0044] The first stirring device is used to enhance the reaction between waste lithium battery materials and chlorine gas, making the reaction between chlorine gas and waste lithium battery materials more thorough and improving the efficiency of metal conversion into metal chloride salts.

[0045] An automatic heating device is used to ensure that the reaction temperature inside the chlorine reaction chamber remains within the high-temperature chlorination roasting temperature range. The automatic heating device is installed on at least one wall of the chlorine reaction chamber to heat the chamber.

[0046] To purge residual reactants from the chlorine reaction chamber, the waste lithium battery material inlet can also be used to introduce inert gas.

[0047] A chlorine control valve is installed on the pipeline connected to the chlorine atmosphere inlet to control the supply of chlorine atmosphere. When the reaction is complete and it is necessary to purge the residue in the chlorine reaction chamber, an inert gas, such as nitrogen, can also be introduced through the chlorine atmosphere inlet for purging.

[0048] In an optional embodiment, a second solution collection chamber is also included, and the chlorine reaction chamber further includes a volatile gas outlet, which is connected to the second solution collection chamber via a pipeline.

[0049] Preferably, the volatile gas outlet is located at the top of the chlorine reaction chamber to facilitate gas discharge.

[0050] Preferably, a condenser is also provided on the pipe connecting the volatile gas outlet and the second solution collection chamber, and the condenser is installed on the outer wall of the pipe.

[0051] Preferably, the condenser is equipped with an inlet water control valve and an outlet water control valve for controlling the use of the condenser.

[0052] Preferably, the water immersion kettle is also equipped with a solid slag outlet, a second stirring device, and a transparent slot.

[0053] The solid slag outlet is installed at the bottom of the water immersion tank, and a third valve is installed on the solid slag outlet to control the discharge of unreacted insoluble solids from waste lithium batteries.

[0054] The transparent slot is installed on the outer wall of the water immersion vessel and at the pipe connected to the first solution collection chamber. It is used to adjust the position of the pipe and is set as a visible surface so that the material state inside the reactor can be observed.

[0055] Preferably, the water immersion tank is a mobile leachate discharge device. The mobile leachate discharge device can better solve the problem of different slag quantities caused by differences in the amount of material. Unlike the traditional pumping process, using this device can reduce power consumption and lower costs.

[0056] Preferably, the pipe connecting the water immersion vessel and the first solution collection chamber is a flexible hose, and one end of the flexible hose connected to the water immersion vessel is a second valve for controlling the discharge of liquid from the water immersion vessel.

[0057] Preferably, the upper part of the water immersion vessel is also connected to a water inlet pipe, and a fourth valve is installed on the water inlet pipe to facilitate control of the aqueous solution being poured into the water immersion vessel.

[0058] In an optional embodiment, a heater is also included. The heater includes an inert gas inlet, a solid inlet, and a heater outlet. The heater outlet is connected to the waste lithium battery material inlet via a pipeline. A fifth valve is also installed on the pipeline to control the introduction of both solid waste lithium battery material and inert gas into the chlorine reaction chamber.

[0059] A sixth valve is installed on the inert gas inlet pipe to control the inert gas entering the heater.

[0060] Since the waste lithium battery materials may cause heat loss when entering the chlorine reaction chamber through the heater via pipes, resulting in changes in the reaction temperature during the chlorination roasting process, setting up an automatic heating device in the chlorine reaction chamber can better control the temperature during the roasting process and ensure that the reaction temperature in the chlorine reaction chamber is within ±3℃ of the preset temperature.

[0061] Preferably, the inert gas inlet is located at the top of the heater and is used to introduce inert gas to remove oxygen-containing gas from the heater and the chlorine reaction chamber; the solid inlet is located at the bottom of the heater and is used to add waste lithium battery materials; and the heater outlet is located at the top of the heater and is used to discharge inert gas and waste lithium battery materials.

[0062] Preferably, the heater is a disc heater, which can ensure that the waste lithium battery material particles are heated evenly during the rolling process, and prevent differences in the chemical reaction during chlorination caused by temperature differences in the waste lithium battery materials.

[0063] Thirdly, the present invention provides an application of the method or apparatus as described in any of the foregoing embodiments in the field of recycling valuable metals from batteries.

[0064] The beneficial effects of the embodiments of the present invention are:

[0065] This invention provides a method, equipment, and application for high-temperature chlorination roasting of spent lithium-ion batteries. By employing high-temperature chlorination roasting, valuable metals in the spent lithium-ion battery materials are converted into metal chlorides. The reactants are then dissolved in water. Since only metals react with chlorine gas to form soluble metal chlorides, the metal chlorides are dissolved in water according to their different solubilities, thus allowing the valuable metals in the spent lithium-ion battery materials to be recycled. This method avoids the use of reducing agents, does not generate large amounts of leachate, is environmentally friendly, and achieves a high recovery rate of valuable metals. Attached Figure Description

[0066] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 This is a schematic diagram of the equipment for high-temperature chlorination roasting of waste lithium batteries provided in Embodiment 1 of the present invention.

[0068] Icons: 100 - Equipment for high-temperature chlorination roasting of waste lithium batteries; 110 - Heater; 111 - Solid inlet; 120 - Chlorine reaction chamber; 121 - Volatile gas outlet; 122 - First stirring device; 130 - Water immersion kettle; 131 - Second stirring device; 132 - Transparent slot; 140 - First solution collection chamber; 150 - Second solution collection chamber; 160 - Condenser; 171 - First valve; 172 - Second valve; 173 - Third valve; 174 - Fourth valve; 175 - Fifth valve; 176 - Sixth valve; 177 - Chlorine control valve; 178 - Inlet water control valve; 179 - Outlet water control valve. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0070] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0071] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0072] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0073] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0074] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0075] Example 1

[0076] Please refer to Figure 1 This embodiment provides a device 100 for high-temperature chlorination roasting of waste lithium batteries, which includes a heater 110, a chlorine reaction chamber 120, a water immersion kettle 130, a first solution collection chamber 140, and a second solution collection chamber 150.

[0077] Heater 110 is a disc heater, including an inert gas inlet, a solid inlet 111, and a heater outlet.

[0078] The inert gas inlet is located at the top of the heater 110. A sixth valve 176 is installed on the pipe connected to the inert gas inlet to control the inert gas entering the heater 110 in order to remove the oxygen-containing gas in the heater 110 and the chlorine reaction chamber.

[0079] The solid inlet 111 is located at the bottom of the heater 110 and is connected to the disc structure inside the heater 110. It is used to add waste lithium battery materials into the disc structure so that the waste lithium battery material particles are heated evenly during the rolling process, and to prevent differences in chemical reactions during the chlorination process caused by temperature differences in the waste lithium battery materials.

[0080] The heater outlet is located at the top of the heater 110 and is connected to the chlorine reaction chamber 120 via a pipe. A fifth valve 175 is also installed on the pipe to control the introduction of solid waste lithium battery materials and inert gas into the chlorine reaction chamber.

[0081] The chlorine reaction chamber 120 includes a chlorine atmosphere inlet, a waste lithium battery material inlet, a reactant outlet, and a volatile gas outlet 121.

[0082] A chlorine control valve 177 is installed on the pipeline connected to the chlorine atmosphere inlet to control the supply of chlorine atmosphere. When the reaction is completed and it is necessary to purge the residue in the chlorine reaction chamber 120, an inert gas, such as nitrogen, can also be introduced through the chlorine atmosphere inlet for purging.

[0083] The waste lithium battery material inlet is connected to the heater outlet through a pipe with a fifth valve 175, for introducing inert gas and waste lithium battery material.

[0084] The reactant outlet is connected to the water immersion vessel 130 via a pipe. A first valve 171 is installed on the pipe to control the entry of the reactant into the water immersion vessel 130.

[0085] The volatile gas outlet 121 is located at the top of the chlorine reaction chamber 120 and is connected to the second solution collection chamber 150 via a pipeline.

[0086] A condenser 160 is also installed on the pipe connecting the volatile gas outlet 121 and the second solution collection chamber 150. The condenser 160 is installed on the outer wall of the pipe. An inlet control valve 178 and an outlet control valve 179 are installed on the condenser 160 to control its operation.

[0087] The chlorine reaction chamber 120 is also equipped with a first stirring device 122 and an automatic heating device (not shown in the figure).

[0088] The first stirring device 122 is a stirring component with blades. The first stirring device 122 is installed at the lower part of the chlorine reaction chamber 120, and the axial direction of the first stirring device 122 intersects with the extension line of the reactant outlet. It is used to enhance the reaction between waste lithium battery materials and chlorine, so that the reaction between chlorine and waste lithium battery materials is more thorough and the efficiency of metal conversion into metal chloride salt is improved.

[0089] The automatic heating device is used to ensure that the reaction temperature in the chlorine reaction chamber is within the temperature range of high-temperature chlorination roasting.

[0090] The water leaching vessel 130 is a mobile leachate discharge device, including a reactant inlet, a water inlet, a first solution outlet, and a solid residue outlet.

[0091] The reactant inlet is connected to the reactant outlet through a pipe with a first valve 171, which is used to send the reactants in the chlorine reaction chamber into the water immersion kettle 130.

[0092] The upper part of the water immersion vessel 130 is also connected to a water inlet pipe, and a fourth valve 174 is installed on the water inlet pipe to facilitate the control of the water solution being poured into the water immersion vessel 130.

[0093] The first solution outlet is connected to the first solution collection chamber 140 via a hose, and a second valve 172 is installed at one end of the hose connected to the water immersion vessel 130 to control the products generated by the reaction of waste lithium battery materials and chlorine gas to enter the water immersion vessel 130 for processing and then flow into the first solution collection chamber 140.

[0094] The solid slag outlet is installed at the bottom of the water immersion tank 130, and a third valve 173 is installed on the solid slag outlet to control the discharge of unreacted insoluble solid substances from waste lithium batteries.

[0095] The water immersion vessel 130 is also equipped with a second stirring device 131 and a transparent slot 132.

[0096] The second stirring device 131 is installed on the top of the water immersion vessel 130 and extends along the bottom of the water immersion vessel 130. It is used to stir the reaction, improve the solubility of metal chloride salt, and thus improve the metal recovery rate.

[0097] The transparent slot 132 is installed at the first solution outlet on the outer wall of the water immersion vessel 130. The hose can be moved within the transparent slot 132 to adjust the position of the hose. At the same time, it is set as a visible surface, which allows observation of the material state inside the reactor.

[0098] The working principle of the high-temperature chlorination roasting device 100 for waste lithium batteries provided in this embodiment is as follows:

[0099] During high-temperature chlorination roasting, pure water is first added to the first solution collection chamber 140, the second solution collection chamber 150, and the water immersion vessel 130. The fifth valve 175 is opened, and the heater 110 is turned on to heat the heater 110 to the required roasting temperature. The sixth valve 176 is opened to introduce nitrogen into the heater 110, filling the heater 110 and the chlorine reaction chamber with nitrogen. When the nitrogen content in the heater 110 is above 99.5% and the temperature of the heater 110 is the roasting temperature, the waste lithium battery material enters the disc-shaped structure of the heater 110 from the solid inlet 111 for heating. The waste lithium battery material flows out from the heater outlet along the disc-shaped structure and enters the chlorine reaction chamber 120 from the waste lithium battery material inlet through the fifth valve 175. When the waste lithium battery material occupies 1 / 3 of the volume of the chlorine reaction chamber 120, the heater 110 stops heating. After the waste lithium battery materials have completely entered the chlorine reaction chamber 120, close the fifth valve 175 and turn on the automatic heating device and the first stirring device 122 of the chlorine reaction chamber 120. Open the chlorine control valve 177, and the chlorine atmosphere enters the chlorine reaction chamber 120 from the chlorine atmosphere inlet. The waste lithium battery materials and chlorine react fully under the stirring action of the first stirring device 122. Maintain the above conditions until the reaction is completed.

[0100] During the above reaction, the inlet control valve 178 and the outlet control valve 179 are kept open, and cooling water flows in the condenser 160, so that the gas overflowing during the reaction is condensed and flows into the second solution collection chamber 150 along the pipeline.

[0101] After the reaction is complete, the first stirring device 122 is turned off, and the chlorine atmosphere in the chlorine atmosphere inlet is switched to nitrogen. The nitrogen purges the residual volatile substances in the pipeline connected to the volatile gas outlet 121 into the second solution collection chamber 150. The first valve 171 is opened, and nitrogen purging promotes the reaction products in the chlorine reaction chamber to enter the water immersion vessel 130. The second stirring device 131 of the water immersion vessel 130 is turned on, and the reaction products are fully dissolved in the water immersion vessel 130. During the dissolution process, the dissolution status can be observed through the transparent slot 132.

[0102] After dissolution is complete, open the second valve 172 to discharge the first solution into the first solution collection chamber 140 through the hose. After the solution discharge is complete, open the third valve 173 to discharge the insoluble solids into the water immersion kettle 130 through the solid slag outlet and the third valve 173.

[0103] Example 2

[0104] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, applicable to the equipment of Embodiment 1. The method includes the following steps:

[0105] S1. Preparation of waste lithium battery materials

[0106] Waste lithium batteries were placed in a 12% NaCl solution for discharge treatment, and then cleaned, dried, crushed and disassembled. The disassembled waste lithium batteries were then immersed in an 8% nitric acid solution for 5 minutes.

[0107] After leaching, the waste lithium batteries are dried at 80℃ for 5 hours. The dried waste lithium batteries are then crushed into granules with a particle size of less than 1mm to obtain waste lithium battery material.

[0108] S2, High-temperature chlorine roasting

[0109] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at a temperature of 550°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at a temperature of 550°C for 90 minutes.

[0110] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1. The chlorine atmosphere is replenished every 8 minutes, and each replenishment of chlorine atmosphere accounts for 1.5% of the volume of the chlorine reaction chamber.

[0111] For example, in this embodiment, the volume of the chlorine reaction chamber is 1500L, so the volume of chlorine atmosphere replenished each time is 30L.

[0112] S3, Separation and recovery of metal elements

[0113] Collect the reactants from step S2, dissolve them in water, and after the soluble substances have fully dissolved, perform solid-liquid separation on the solution. Collect the liquid, which is the first solution.

[0114] Collect the gas that continues to overflow during step S2, and absorb it by passing the gas into water to obtain a second solution.

[0115] The first and second solutions were mixed and dried together at 70°C for 30 hours.

[0116] Example 3

[0117] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0118] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at a temperature of 650°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at a temperature of 650°C for 90 minutes.

[0119] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1.

[0120] Example 4

[0121] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0122] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at a temperature of 750°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at a temperature of 750°C for 90 minutes.

[0123] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1.

[0124] Example 5

[0125] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0126] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at 850°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at 850°C for 90 minutes.

[0127] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1.

[0128] Example 6

[0129] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0130] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at 850°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at 850°C for 90 minutes.

[0131] The chlorine atmosphere is a mixture of chlorine and nitrogen gases, with a volume ratio of chlorine to nitrogen of 1:1.

[0132] Example 7

[0133] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0134] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at 850°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at 850°C for 90 minutes.

[0135] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 3:1.

[0136] Example 8

[0137] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0138] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at 850°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at 850°C for 60 minutes.

[0139] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1.

[0140] Example 9

[0141] This embodiment provides a method for high-temperature chlorination roasting of spent lithium batteries, the preparation method of which is the same as that in Embodiment 2, the only difference being the following steps:

[0142] In an oxygen-free environment, waste lithium battery materials are placed in a disc heater for preheating at a temperature of 850°C. The preheated waste lithium battery materials are then placed in a chlorine reaction chamber and roasted in a chlorine atmosphere at a temperature of 850°C for 120 minutes.

[0143] The chlorine atmosphere is a mixture of chlorine and nitrogen, with a volume ratio of chlorine to nitrogen of 2:1.

[0144] Experimental Example 1

[0145] The waste lithium battery material prepared in step S1 of Example 2 was analyzed and tested, and the main metal element composition was confirmed to be Ni: 1.42%, Co: 51.52%, Li: 7.21%, Mn: 7.34%, and C: 0.77%.

[0146] The solid materials recovered in Examples 2 to 9 were subjected to the same analysis and testing to obtain the above-mentioned metal element composition of the solid materials recovered in Examples 2 to 9. The recovery rate was calculated using the formula: Recovery rate = Actual product mass / Theoretical product mass × 100%, and the results are shown in Table 1.

[0147] The theoretical product mass can be calculated based on the chemical reaction equations of each metal element and chlorine gas, for example, see the following equation:

[0148] 6LiCoO2+3Cl2(g)——6LiCl+2Co3O4+2O2(g);

[0149] 2Co3O4+3Cl2(g)——6CoCl+4O2(g);

[0150] 2LiNiO2+3Cl2(g)——2NiCl2+2LiCl+2O2(g);

[0151] 2LiMn2O4+Cl2(g)——2LiCl+2Mn2O3+O2(g);

[0152] 2Mn2O3+4Cl2(g)——4MnCl2+3O2(g).

[0153] Table 1 Metal recovery rate

[0154] Li / % Mn / % Ni / % Co / % Example 2 53.21 64.25 24.26 1.04 Example 3 74.26 77.87 52.99 11.21 Example 4 88.93 91.22 73.61 43.56 Example 5 94.96 96.58 81.22 68.69 Example 6 90.88 91.52 77.23 61.07 Example 7 95.06 96.70 81.28 69.16 Example 8 79.58 81.24 70.29 54.22 Example 9 94.94 97.01 82.02 69.09

[0155] As shown by the above data, the high-temperature chlorination roasting method for waste lithium batteries provided by this invention achieves high metal recovery rates when recycling metals from waste lithium battery materials. The recovery rates for lithium metal can reach 95.06%, manganese metal 97.01%, nickel metal 82.02%, and cobalt metal 69.16%. Furthermore, this method does not generate polluting gases or leachate, demonstrating significant development potential.

[0156] The present invention provides a method, apparatus, and application for high-temperature chlorination roasting of spent lithium batteries, which has at least the following advantages:

[0157] 1. A high-temperature chlorination roasting method is used to chlorinate the main metallic elements in waste lithium battery materials, such as nickel, cobalt, lithium, and manganese. The resulting metal chloride salts are all soluble salts. The non-metallic components in the waste lithium battery materials do not react with chlorine gas and are also insoluble in water. Therefore, the differences in solubility of the components in the reactants can be utilized. When the reactants are placed in water, the metal chloride salts dissolve in the water, while the non-metallic components remain in the water as solids. After solid-liquid separation, the collected liquid is the first solution rich in metal elements, and the metals in the first solution can be recovered and reused.

[0158] This method converts the metal elements in spent lithium batteries into soluble metal chlorides, and then uses the differences in solubility of the components in the spent lithium batteries to separate the metals from other impurities, thereby recycling the valuable metal elements in the spent lithium batteries. This method not only avoids the use of reducing agents and does not generate large amounts of leachate, but is also environmentally friendly and achieves a high recovery rate of valuable metals.

[0159] 2. Adding a protective gas to the chlorine atmosphere is for safety reasons during the reaction process. At the same time, using a large amount of high-purity chlorine will not only lead to the waste of chlorine, but the emission of chlorine will also bring some environmental problems.

[0160] Furthermore, the high-temperature chlorine roasting process of the present invention is not a rapid reaction process. It is necessary to ensure that the waste lithium battery materials remain in contact with the high-temperature chlorine gas for a certain period of time. Therefore, in order to ensure the smooth progress of the reaction and avoid reaction accidents, a protective gas should be added to the chlorine atmosphere.

[0161] This invention provides a method for setting a reasonable ratio of nitrogen and chlorine, which not only ensures the utilization rate of chlorine in the reaction and avoids waste of chlorine, but also ensures the safety of the reaction process.

[0162] 3. Since the temperature is high during the roasting process and chlorine is also easy to volatilize, the volatilized chlorine will carry a small amount of metal. Therefore, using an aqueous solution to absorb the gas can recover a small amount of metal elements in the gas, while absorbing chlorine, thus avoiding environmental pollution caused by direct discharge of chlorine.

[0163] 4. The disc heater can ensure that the waste lithium battery material particles are heated evenly during the rolling process, preventing differences in the chemical reaction during chlorination caused by temperature differences in the waste lithium battery materials.

[0164] 5. The mobile leachate discharge device can effectively solve the problem of different slag quantities caused by differences in material quantity. Unlike the traditional pumping process, using this device can reduce power consumption and lower costs.

[0165] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for high-temperature chlorination roasting of spent lithium batteries, characterized in that, The method includes roasting waste lithium battery materials in a closed environment under a chlorine atmosphere, dissolving the roasted reactants in water to obtain a first solution, and recovering metals from the first solution; the roasting temperature is 550~850℃ and the roasting time is 60~120min. The gas volatilized during the roasting process is absorbed by water to obtain a second solution; the metal recovery involves mixing the first solution and the second solution and drying them together; the drying temperature is 70~90℃ and the drying time is 20~30h.

2. The method according to claim 1, characterized in that, The chlorine atmosphere includes chlorine and a protective gas; The protective gas includes at least one of nitrogen, helium, or argon.

3. The method according to claim 2, characterized in that, The chlorine atmosphere is a mixture of chlorine and nitrogen. The volume ratio of chlorine to nitrogen is 1 to 3:

1.

4. The method according to claim 3, characterized in that The volume ratio of chlorine to nitrogen is 2~3:

1.

5. The method according to any one of claims 2 to 4, characterized in that, It also includes replenishing the closed environment of the roasting with chlorine atmosphere, wherein the chlorine atmosphere is replenished once every 5 to 10 minutes, and the chlorine atmosphere replenished each time accounts for 1 to 2% of the volume of the closed environment.

6. The method according to claim 1, characterized in that, The roasting temperature is 750~850℃, and the roasting time is 90~120min.

7. The method according to claim 1, characterized in that, The roasting temperature is 850℃ and the roasting time is 90 minutes.

8. The method according to claim 1, characterized in that The method for preparing the waste lithium battery material includes: leaching the waste lithium battery in a nitric acid solution, drying it, and crushing it into granules.

9. The method according to claim 8, characterized in that, The nitric acid solution has a mass fraction of 8-10%, and the leaching time is 3-5 minutes.

10. The method according to claim 8, characterized in that, The drying temperature is 60~80℃, and the drying time is 5~6 hours.

11. The method according to claim 8, characterized in that, Before leaching, the waste lithium batteries also undergo sequential discharge treatment, cleaning, drying, crushing and dismantling.

12. The method according to claim 11, characterized in that, The discharge treatment includes placing the waste lithium batteries in a NaCl solution with a mass fraction of 10-15%.

13. A device for high-temperature chlorination roasting of waste lithium batteries, characterized in that, The method applicable to any one of claims 1 to 12 includes a chlorine reaction chamber, a water immersion vessel, and a first solution collection chamber: The chlorine reaction chamber includes a chlorine atmosphere inlet, a waste lithium battery material inlet, and a reactant outlet. The reactant outlet is connected to the water immersion vessel via a pipeline, and the water immersion vessel is connected to the first solution collection chamber via a pipeline, so that the product of the reaction between the waste lithium battery material and chlorine enters the water immersion vessel for treatment and then flows into the first solution collection chamber. The chlorine reaction chamber is also equipped with a first stirring device and an automatic heating device. The first stirring device is used to enhance the reaction between the waste lithium battery material and chlorine.

14. The device according to claim 13, characterized in that, It also includes a second solution collection chamber, and the chlorine reaction chamber further includes a volatile gas outlet, which is connected to the second solution collection chamber via a pipeline.

15. The device according to claim 14, characterized in that, A condenser is also installed on the pipe connecting the volatile gas outlet and the second solution collection chamber, and the condenser is installed on the outer wall of the pipe.

16. The device according to claim 13, characterized in that, The water immersion kettle is also equipped with a solid slag outlet, a second stirring device, and a transparent slot. The transparent slot is installed on the outer wall of the water immersion kettle and at the pipe connected to the first solution collection chamber for adjusting the position of the pipe. The solid slag outlet is installed at the bottom of the water immersion kettle for discharging insoluble solid substances.

17. The device according to claim 13, characterized in that, The water immersion vessel is a movable leachate discharge device, and the pipe connecting the water immersion vessel and the first solution collection chamber is a flexible hose.

18. The device according to any one of claims 14 to 17, characterized in that, It also includes a heater, which has an inert gas inlet, a solid inlet, and a heater outlet, the heater outlet being connected to the waste lithium battery material inlet via a pipeline.

19. The device according to claim 18, characterized in that, The inert gas inlet is located at the top of the heater and is used to introduce inert gas to remove oxygen-containing gas from the heater and the chlorine reaction chamber. The solid inlet is located at the bottom of the heater and is used to add waste lithium battery materials. The heater outlet is located at the top of the heater and is used to discharge inert gas and waste lithium battery materials.

20. The device according to claim 19, characterized in that, The heater is a disc heater.

21. The application of the method as described in any one of claims 1 to 12 or the apparatus as described in any one of claims 13 to 20 in the field of recycling valuable metals from batteries.

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