Safe crushing and efficient separation method of lithium thionyl chloride battery

Abstract

The invention provides a safe crushing and efficient separation method of a lithium thionyl chloride battery, which comprises the following steps: firstly, performing low-temperature freezing treatment before crushing treatment of the lithium thionyl chloride battery, so that the battery voltage in the subsequent crushing process can be kept to be zero, no current is generated in the battery, and the combustion and explosion risks during crushing are reduced; then, acid pickling treatment is carried out on the crushed material of the battery, soluble components such as lithium-containing compounds in the battery can be dissolved in a targeted mode, effective separation of lithium and other insoluble substances is achieved, and therefore the lithium resource can be efficiently recycled, and the recovery rate of lithium is increased; finally, the lithium-containing waste residues are dried and subjected to magnetic separation treatment, the stainless steel shells and the carbon powder can be accurately separated out, comprehensive recycling and classified utilization of different components in the batteries are achieved through the refined waste residue treatment mode, the comprehensive utilization rate of resources is increased, waste emission is reduced, and the method is suitable for industrial production. The concept of environmental protection and resource recycling is met.

Description

Technical Field

[0001] The invention relates to the technical field of waste recycling, and in particular to a method for safely crushing and efficiently separating lithium thionyl chloride batteries. Background Art

[0002] Lithium thionyl chloride batteries have high battery voltage, specific energy density, low self-discharge rate, good storage performance, a wide range of operating environments, and can withstand ambient temperatures generally ranging from -40°C to 85°C. Therefore, based on the above characteristics, they are widely used in military, wireless communications, and medical equipment industries. However, if the batteries are not properly handled after being discarded, they are prone to polluting the environment. The current threshold for battery recycling is high, and there are few reports on the recycling technology of discarded lithium thionyl chloride batteries in China.

[0003] One treatment option for the above-mentioned waste lithium thionyl chloride batteries is to bury them directly after soaking and discharging. This not only wastes valuable metal resources and violates the concept of sustainable development, but also increases the risk of pollution to local soil and groundwater, destroys the balance of the ecosystem, and affects biodiversity. Another option is to disassemble the battery, separate the electrolyte, and then recycle the remaining battery materials. This option is feasible, but the process is relatively complicated, the separation cost is very high, and the mechanical cutting and separation process will produce the risk of explosion and combustion, and a large amount of toxic gases such as SO2 and HCl will be released, causing pollution and harm to the environment and human body.

[0004] Therefore, there is an urgent need for a safe crushing and efficient separation method for lithium thionyl chloride batteries to solve the above technical problems. Summary of the invention

[0005] The object of the present invention is to provide a method for safely crushing and efficiently separating lithium thionyl chloride batteries, so as to solve the technical problem that it is difficult to safely recycle and efficiently separate waste lithium thionyl chloride batteries in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a safe crushing and efficient separation method for lithium thionyl chloride batteries, comprising: S10, performing low-temperature freezing treatment on the lithium thionyl chloride battery to obtain a frozen material, wherein the temperature of the low-temperature freezing treatment is -104°C to -196°C; S20, crushing the frozen material to obtain battery crushed material; S30, performing acid washing on the battery crushed material to obtain a lithium-containing solution and lithium-containing waste residue after solid-liquid separation; S40, drying and magnetically separating the lithium-containing waste residue, and obtaining a stainless steel shell and carbon powder after screening.

[0007] Preferably, in step S10: the lithium thionyl chloride battery is subjected to a low-temperature freezing treatment in a liquid nitrogen immersion mode or a liquid nitrogen gasification mode, and the low-temperature freezing treatment time is 5 minutes to 30 minutes.

[0008] Preferably, in step S20: the frozen material is placed in a crushing device for crushing to obtain battery crushed material with an output particle size not exceeding 20 mm.

[0009] Preferably, the crushing equipment includes a soundproof cover, a multi-axis shredder and a negative pressure exhaust gas treatment device, the multi-axis shredder is located inside the soundproof cover, and the first end of the negative pressure exhaust gas treatment device is respectively connected to the soundproof cover and the multi-axis shredder.

[0010] Preferably, the second end of the negative pressure tail gas treatment device is also connected to an alkaline tail gas absorption tower.

[0011] Preferably, step S30 specifically includes: S301, the battery crushed material is transported to a stirring barrel through a multi-stage screw to be immersed in water, and then an acid solution is added to the stirring barrel to obtain a lithium-containing washing solution after complete reaction; S302, separating the first lithium-containing solution in the lithium-containing washing liquid through the middle discharge port of the conical stirring shaft of the stirring barrel, and adding an equal amount of pure water to the stirring barrel to perform pure water washing on the remaining lithium-containing washing liquid; S303, collecting the remaining lithium-containing washing solution through the bottom discharge port of the stirring barrel, and performing solid-liquid separation on the remaining lithium-containing washing solution through a sand-water separator to obtain a second lithium-containing solution and lithium-containing waste residue, and the first lithium-containing solution and the second lithium-containing solution are mixed to obtain a lithium-containing solution.

[0012] Preferably, in step S301: a screw conveying device is used to perform multi-stage screw conveying processing on the battery crushed material; Among them, the spiral conveying equipment includes a spiral silo and a feeding spiral conveyor belt connected to the spiral silo; the spiral silo is located inside the sound insulation cover and is connected to the unloading port of the multi-axis shredder, and one end of the feeding spiral conveyor belt is connected to the top feeding port of the mixing barrel.

[0013] Preferably, in step S301: the acidic solution is sulfuric acid or hydrochloric acid, and the pH value of the lithium-containing washing solution is 6-7.

[0014] Preferably, after step S30 is completed, the method further includes: preparing battery-grade lithium carbonate from the lithium-containing solution by a sodium carbonate precipitation method.

[0015] Preferably, in step S40: the magnetic field intensity of the magnetic separation treatment is 9000GS~12000GS.

[0016] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides a safe crushing and efficient separation method for lithium thionyl chloride batteries, which firstly performs a low-temperature freezing treatment before the lithium thionyl chloride batteries are crushed, so that the battery voltage in the subsequent crushing process can be kept at zero, so that no current is generated inside the battery, thereby reducing the risk of combustion and explosion during crushing; thereafter, acid washing the crushed battery material can specifically dissolve soluble components such as lithium-containing compounds in the battery, and realize effective separation of lithium and other insoluble substances (such as stainless steel shells, carbon powder, etc. in waste slag), so that lithium resources can be efficiently recovered and the recovery rate of lithium can be improved, which is of great significance for the recycling of lithium resources; finally, the lithium-containing waste slag is dried and magnetically separated, so that the stainless steel shell and carbon powder can be accurately separated, and this refined waste slag treatment method realizes the comprehensive recovery and classified utilization of different components in the battery, improves the comprehensive utilization rate of resources, reduces the emission of waste, and conforms to the concept of green environmental protection and resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a method for safely crushing and efficiently separating lithium thionyl chloride batteries provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a refrigeration system in a method for safe crushing and efficient separation of lithium thionyl chloride batteries provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a separation system in a method for safe crushing and efficient separation of lithium thionyl chloride batteries provided in an embodiment of the present invention; Figure 4 A process flow chart of the safe crushing and efficient separation method of lithium thionyl chloride batteries provided in Example 1 of the present invention; In the attached figure: 10 - refrigeration system; 101 - liquid nitrogen freezer 101; 102 - control cabinet; 103 - mobile liquid nitrogen cabinet; 104 - battery freezing material frame; 20 - separation system; 201 - belt conveyor; 202 - multi-axis shredder; 203 - soundproof cover; 204 - spiral silo; 205 - feeding spiral conveyor belt; 206 - alkaline tail gas absorption tower; 207 - mixing barrel; 208 - sand and water separator. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The purpose of the present invention is to overcome the above technical deficiencies and provide a method for safely crushing and efficiently separating lithium thionyl chloride batteries, so as to solve the technical problem that it is difficult to safely recycle and efficiently separate waste lithium thionyl chloride batteries in the prior art.

[0020] See also Figures 1 to 3 , Figure 1 A flow chart of a safe crushing and efficient separation method for lithium thionyl chloride batteries provided in an embodiment of the present invention; wherein the safe crushing and efficient separation method for lithium thionyl chloride batteries specifically includes: S10, performing low temperature freezing treatment on the lithium thionyl chloride battery to obtain a frozen material, the temperature of the low temperature freezing treatment is -104°C to -196°C.

[0021] Specifically, step S10 also includes: First, waste lithium thionyl chloride batteries are provided. Lithium thionyl chloride batteries are electrochemical power sources that use metal lithium as the negative electrode, liquid thionyl chloride as the positive electrode active material, a glass fiber material that can provide support strength as the separator, and porous carbon as the positive electrode current collector; Among them, SOCl2 is both a reactant and a non-aqueous inorganic solvent. The solution after dissolving additives such as LiAlCl4 is an inorganic electrolyte. This system battery is a new type of high-energy chemical power source developed in recent years. The overall reaction mechanism is: 4Li+2SOCl2→4LiCl+S+SO2. When the battery is discharged, elemental sulfur is generated and attached to the surface of the positive electrode carbon black in situ, and the electrolyte becomes LiCl until the reaction is terminated.

[0022] Afterwards, the lithium thionyl chloride battery is subjected to low-temperature freezing treatment to obtain frozen material. The temperature of the low-temperature freezing treatment is -104℃~-196℃, and the time of the low-temperature freezing treatment is 5min~30min. Among them, the freezing point of SOCl2 is -104℃. When the temperature is lowered below the freezing point, it can be ensured that no current is generated inside the battery. At the same time, it is necessary to ensure that the electrolyte is in a frozen state during the crushing process, which requires more than 5min of sufficient time. According to calculations, the battery can be frozen to about -196℃, which can meet the requirement of no voltage in the battery within 5min.

[0023] Preferably, the lithium thionyl chloride battery is cryogenically frozen by liquid nitrogen immersion mode or liquid nitrogen gasification mode; wherein, the liquid nitrogen immersion mode is adopted when lithium thionyl chloride batteries are processed in large batches, and the temperature is not controlled at -196°C; the gasification mode is adopted when lithium thionyl chloride batteries are processed in small batches, and the temperature can be adjusted from room temperature to -196°C; switching between the two modes can greatly reduce the consumption of liquid nitrogen, and the insulation system is vacuum insulation.

[0024] See also Figure 2 , Figure 2A schematic structural diagram of a refrigeration system 10 in a method for safe crushing and efficient separation of lithium thionyl chloride batteries provided in an embodiment of the present invention; wherein the refrigeration system 10 comprises a liquid nitrogen freezer 101, a control cabinet 102 electrically connected to the liquid nitrogen freezer 101, and a mobile liquid nitrogen cabinet 103 connected to the interior of the liquid nitrogen freezer 101, and a battery freezing material frame 104 is provided inside the liquid nitrogen freezer 101, and the battery freezing material frame 104 is used to load discarded lithium thionyl chloride batteries.

[0025] S20, crushing the frozen material to obtain battery crushed material.

[0026] Specifically, step S20 also includes: The frozen materials are placed in crushing equipment for crushing to obtain battery crushed materials with a particle size not exceeding 20 mm.

[0027] See also Figure 3 , Figure 3 A schematic diagram of the structure of a separation system 20 in a safe crushing and efficient separation method for lithium thionyl chloride batteries provided in an embodiment of the present invention; wherein the separation system 20 comprises a belt conveyor 201 and crushing equipment, one end of the belt conveyor 201 is connected to a refrigeration system 10, and the other end of the belt conveyor 201 is connected to a multi-axis shredder 202 ( Figure 3 The belt conveyor 201 is connected to the top feed bin of the multi-axis shredder 202 and is used to transfer the frozen materials to the multi-axis shredder 202.

[0028] Specifically, the crushing equipment includes a soundproof cover 203, a multi-axis shredder 202 and a negative pressure exhaust gas treatment device. The multi-axis shredder 202 is located inside the soundproof cover 203. The first end of the negative pressure exhaust gas treatment device is connected to the soundproof cover 203 and the multi-axis shredder 202 respectively, and the second end of the negative pressure exhaust gas treatment device is also connected to an alkaline exhaust gas absorption tower 206.

[0029] Furthermore, the soundproof cover 203 is used to absorb the noise generated when the battery is crushed, and collect the toxic and harmful gases generated when the battery is crushed; the multi-axis shredder 202 has a strong shearing and crushing ability, which can efficiently crush the lithium thionyl chloride battery into smaller particles, providing a suitable material particle size for subsequent pickling treatment. During the pickling process, the smaller particle size can increase the contact area between the material and the pickling solution, thereby improving the efficiency of the pickling reaction. The uniform particle size distribution also helps to ensure the uniformity of the pickling reaction, avoiding the situation where some materials do not react sufficiently and some materials over-react.

[0030] Furthermore, the negative pressure tail gas treatment device is used to transport the toxic and harmful gases generated when the lithium thionyl chloride battery is crushed to the alkaline tail gas absorption tower 206 for spraying treatment.

[0031] S30, performing acid washing on the battery crushed material, and obtaining a lithium-containing solution and lithium-containing waste residue after solid-liquid separation.

[0032] Specifically, step S30 also includes: S301, the battery crushed materials are conveyed to the stirring barrel 207 through a multi-stage screw conveyor for water immersion treatment, and then an acid solution is added to the stirring barrel 207 to obtain a lithium-containing washing solution after complete reaction; wherein, the battery crushed materials are conveyed to the stirring barrel 207 through a multi-stage screw conveyor using a screw conveying equipment.

[0033] For further information, see Figure 3 The separation system 20 also includes a spiral conveying device and a stirring barrel 207. The spiral conveying device includes a spiral silo 204 and a feeding spiral conveyor belt 205 connected to the spiral silo 204. The spiral silo 204 is located inside the soundproof cover 203 and is connected to the discharge port of the multi-axis shredder 202. One end of the feeding spiral conveyor belt 205 is connected to the top feeding port of the stirring barrel 207.

[0034] Furthermore, the spiral conveying equipment can realize multi-stage spiral conveying to ensure that the battery crushed materials are stably and continuously conveyed from one location to another. This conveying method can adapt to different conveying distances and height requirements, and effectively convey the battery crushed materials from the crushing area to the mixing barrel 207, providing reliable material transmission guarantee for subsequent processing procedures. The specific process flow and site restrictions can be met by setting a feeding spiral conveyor belt 205 of different lengths, angles and diameters. At the same time, the spiral conveying equipment has good sealing performance, which can reduce the leakage and dust of materials during the transportation process, which is conducive to keeping the working environment clean and safe.

[0035] Furthermore, the battery crushed material is conveyed from the discharge port of the multi-axis shredder 202 to the mixing barrel 207 via a two-stage spiral. The mixing barrel 207 is filled with pure water. The lithium element fully reacts with water to generate lithium hydroxide. The pH value of the solution is strongly alkaline. The reaction equation is as follows: Li+H2O→Li(OH)+½H2. At this time, most of the lithium element in the aqueous solution exists in the form of lithium chloride.

[0036] When the battery crushed materials are put into the mixing barrel 207, a small amount of H2 will be released, and the electrolyte reacts with water to generate SO2. The reaction equation is as follows: SOCl+H2O→SO2+HCl. At this time, the negative pressure exhaust system can be used to draw the toxic gas into the alkaline tail gas absorption tower 206.

[0037] After the reaction of the battery crushed materials with water is completed, a certain amount of acidic solution is added in a molar ratio to control the pH range of the solution between 6 and 7, so that all the lithium hydroxide that is insoluble in water in the solution is converted into lithium chloride that is easily soluble in water, and then a lithium-containing washing solution is obtained; wherein the acidic solution is sulfuric acid or hydrochloric acid, and the pH value of the lithium-containing washing solution is 6~7.

[0038] Furthermore, the pH value of the lithium-containing washing solution is 6-7, which can ensure that the lithium hydroxide can be completely converted into lithium chloride. If the acidity is too strong (the pH is too low), too many hydrogen ions may be introduced, which may cause corrosion to the equipment during subsequent treatment, and may introduce other unnecessary impurity ions. If the acidity is too weak (the pH is too high), the lithium hydroxide cannot react completely, and the lithium hydroxide that is insoluble in water cannot be completely converted into lithium chloride that is easily soluble in water, which will affect the lithium content of the lithium-containing washing solution.

[0039] S302, separating the first lithium-containing solution in the lithium-containing washing liquid through the middle discharge port of the conical stirring shaft of the stirring barrel 207, and adding an equal amount of pure water to the stirring barrel 207 to wash the remaining lithium-containing washing liquid with pure water; wherein, since there are fewer solids in the first lithium-containing solution, it is separated through the middle discharge port of the conical stirring shaft of the stirring barrel 207 to purify the lithium element.

[0040] S303, collecting the remaining lithium-containing washing solution through the bottom discharge port of the stirring barrel 207, and performing solid-liquid separation on the remaining lithium-containing washing solution through the sand-water separator 208 to obtain a second lithium-containing solution and lithium-containing waste residue, and the first lithium-containing solution and the second lithium-containing solution are mixed to obtain a lithium-containing solution.

[0041] Specifically, the sand-water separator 208 is mainly based on the principle of gravity sedimentation and centrifugal force to achieve solid-liquid separation. When the lithium-containing washing liquid enters the sand-water separator 208, due to the different densities of the solid particles (lithium-containing waste residue) and the liquid (lithium-containing washing liquid), under the action of gravity, the heavier solid particles will gradually settle to the bottom of the separator. At the same time, some separators are also equipped with rotating parts, which generate centrifugal force through rotation to accelerate the sedimentation process of solid particles.

[0042] Furthermore, the lithium-containing wash solution contains lithium chloride (LiCl), which is easily soluble in water, and its solution can be used to extract lithium elements through subsequent separation and purification processes. For example, the lithium-containing solution can be prepared into battery-grade lithium carbonate by sodium carbonate precipitation. The sodium carbonate precipitation method is based on the chemical property that lithium carbonate is difficult to dissolve in water. When the sodium carbonate solution is added to the lithium-containing solution, the lithium ions combine with the carbonate ions to form lithium carbonate precipitates, while the sodium ions remain in the solution.

[0043] S40, drying and magnetically separating the lithium-containing waste residue, and obtaining a stainless steel shell and carbon powder after screening.

[0044] Specifically, step S40 also includes: The lithium-containing waste slag is magnetically separated by a magnetic separation belt to obtain a stainless steel shell and carbon powder. The magnetic field intensity of the magnetic separation treatment is 9000GS~12000GS.

[0045] Specifically, the reason why the magnetic field strength is set at 9000GS~12000GS is as follows: If the magnetic field strength is too low, it may not be able to effectively adsorb materials with certain magnetism such as stainless steel shells, resulting in poor separation effect. Stainless steel shells usually have certain weak magnetism, and a magnetic field of sufficient strength is required to separate them from other materials; if the magnetic field strength is too high, it may adsorb too many non-target materials, increasing the difficulty of subsequent separation, and also increasing the energy consumption and cost of the equipment.

[0046] The technical solution of the present application is now further described in detail in conjunction with specific embodiments.

[0047] Embodiment 1: See also Figures 1 to 4 , Figure 4 The process flow chart of the safe crushing and efficient separation method of lithium thionyl chloride batteries provided in Example 1 of the present invention; wherein, the process of the safe crushing and efficient separation method of lithium thionyl chloride batteries provided in Example 1 of the present invention is as follows: ① liquid nitrogen soaking lithium thionyl chloride battery cells (temperature is about -190°C) → put into crushing equipment → ② the battery crushed material is transferred to a conical stainless steel barrel with stirring filled with pure water → ③ sulfuric acid is added to adjust the Ph range to 6-7 → ④ sand and water separator 208 separation → lithium-containing solution is decontaminated and lithium is precipitated.

[0048] Specifically, the detailed steps of the above process are as follows: The specific steps are as follows: Step 1: Place the lithium thionyl chloride battery on the freezer lining frame, cover the freezer cover, open the liquid nitrogen valve, and directly connect the liquid nitrogen to the freezer. When processing in small batches or keeping warm, control the liquid nitrogen level or gasify the liquid nitrogen so that the temperature can be controlled at room temperature -196℃.

[0049] Step 2: After freezing, the thionyl chloride battery is placed on a belt conveyor 201 (1.5m wide) equipped with a partition, and transported to the four-axis shredder silo along the belt conveyor 201, and then enters the crushing chamber for shredding, and the discharge particle size is controlled to be within 20mm (screen mesh number 20). The process does not require nitrogen protection, and negative pressure exhaust draws out the toxic and harmful gases in the shredder to the alkaline spray tower. The overflow gas of the shredder is collected and treated by negative pressure exhaust in the soundproof cover 203.

[0050] Step three, the battery crushed materials are transported from the shredder hopper to the mixing barrel 207 via a two-stage spiral. The mixing barrel 207 is filled with pure water. The lithium element fully reacts with water to generate lithium hydroxide. The pH value of the solution is strongly alkaline. The reaction equation is as follows: Li+H2O→Li(OH)+½H2. At this time, most of the lithium elements in the aqueous solution exist in the form of lithium chloride. At this time, most of the lithium elements in the aqueous solution exist in the form of lithium chloride. When the crushed materials are put into the mixing barrel 207, a small amount of H2 will be released. The electrolyte reacts with water to generate SO2. The reaction equation is as follows: SOCl+H2O→SO2+HCl. At this time, the negative pressure exhaust system can be used to draw the toxic gas into the alkaline tail gas absorption tower 206.

[0051] Step 4, after the battery crushing materials are put into the stirring barrel 207, a certain amount of sulfuric acid is added in a molar ratio to control the solution Ph range between 6-7, and all the lithium hydroxide insoluble in water in the solution is converted into lithium chloride soluble in water. The lithium-containing solution is discharged through the discharge port in the middle of the conical stirring shaft, and then an equal amount of pure water is added for cleaning.

[0052] Step five, the lithium-containing washing liquid is also discharged through the discharge port in the middle of the conical stirring shaft, and the slag sample is discharged through the bottom discharge valve to discharge the solid into the sand-water separator 208, and the lithium-containing waste slag and the lithium-containing washing liquid in the sand-water separator 208 are separated by a spiral.

[0053] Step six: the lithium-containing solution enters the wet process system for concentration, impurity removal, lithium precipitation, drying, and crushing into battery-grade lithium carbonate.

[0054] Step seven, drying and magnetic separation of the solid sample to effectively separate the stainless steel shell and carbon powder.

[0055] According to the composition and properties of lithium thionyl chloride batteries, the research focus of this application is on the recovery and crushing stage of lithium thionyl chloride batteries. Liquid nitrogen immersion is used to effectively reduce the activity of the battery during the crushing process. Specifically, the channel of ions in the electrolyte and the activity of the negative electrode are controlled by extreme low temperature, the battery voltage is kept at zero during the crushing process, and no current is generated inside the battery, thereby reducing the risk of combustion and explosion during crushing.

[0056] In summary, different from the prior art, the safe crushing and efficient separation method of lithium thionyl chloride batteries provided by the present invention has the following advantages: 1. This technology uses liquid nitrogen immersion technology to adjust the refrigeration temperature through the liquid level and temperature controller on the control cabinet 102 to ensure that the battery electrolyte is solidified, the internal electrolyte cannot move, and no current is generated, resulting in the inactivation of the internal battery materials, thereby greatly reducing the risk of combustion and explosion of the internal lithium metal negative electrode during crushing.

[0057] 2. The freezing system 10 can realize the following mode switching: liquid nitrogen immersion mode is used for large-scale battery processing, and the temperature is not controlled at -196°C. Gasification mode is used for small-scale battery processing, and the temperature can be adjusted from room temperature to -196°C. Switching between the two modes can greatly reduce the consumption of liquid nitrogen, and the insulation system is vacuum insulation.

[0058] 3. The frozen acidic liquid electrolyte is converted into a solid electrolyte, which stays in the crushing equipment for a short time, reducing the corrosion damage caused by the acidic electrolyte to the equipment.

[0059] 4. In view of the huge sound (noise) generated during the crushing process, which may cause harm to the employees, a soundproof cover 203 is installed on the multi-axis shredder 202, and the multi-axis shredder 202 is placed in the soundproof cover 203. In view of the large amount of acidic toxic and harmful gases generated during the crushing process, a negative pressure tail gas treatment device is installed on the multi-axis shredder 202 and the soundproof cover 203, which collects toxic and harmful gases at two levels to prevent gas overflow, and passes the tail gas into the alkaline tail gas absorption tower 206 to neutralize the acidic gas.

[0060] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For details not described in individual embodiments, reference may be made to the description in other embodiments.

[0061] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for safe crushing and efficient separation of lithium thionyl chloride batteries, characterized in that: include: S10, performing low-temperature freezing treatment on the lithium thionyl chloride battery to obtain a frozen material, wherein the temperature of the low-temperature freezing treatment is -104°C to -196°C; S20, crushing the frozen material to obtain battery crushed material; S30, performing an acid wash treatment on the battery crushed material to obtain a lithium-containing solution and lithium-containing waste residue after solid-liquid separation; S40, drying and magnetically separating the lithium-containing waste residue, and obtaining a stainless steel shell and carbon powder after screening.

2. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 1 is characterized in that: In the step S10: the lithium thionyl chloride battery is subjected to the low-temperature freezing treatment in a liquid nitrogen immersion mode or a liquid nitrogen gasification mode, and the low-temperature freezing treatment time is 5 minutes to 30 minutes.

3. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 1 is characterized in that: In the step S20: the frozen material is placed in a crushing device for crushing to obtain the battery crushed material with a discharge particle size not exceeding 20 mm.

4. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 3 is characterized in that: The crushing equipment includes a soundproof cover, a multi-axis shredder and a negative pressure exhaust gas treatment device. The multi-axis shredder is located inside the soundproof cover, and the first end of the negative pressure exhaust gas treatment device is respectively connected to the soundproof cover and the multi-axis shredder.

5. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 4 is characterized in that: The second end of the negative pressure tail gas treatment device is also connected to an alkaline tail gas absorption tower.

6. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 4, characterized in that: The step S30 specifically includes: S301, conveying the battery crushed material to a stirring barrel via a multi-stage screw to undergo water immersion treatment, and then adding an acidic solution into the stirring barrel to obtain a lithium-containing washing solution after complete reaction; S302, separating the first lithium-containing solution in the lithium-containing washing liquid through the middle discharge port of the conical stirring shaft of the stirring barrel, and adding an equal amount of pure water to the stirring barrel to perform pure water washing on the remaining lithium-containing washing liquid; S303, collecting the remaining lithium-containing washing solution through the bottom discharge port of the stirring barrel, and performing solid-liquid separation treatment on the remaining lithium-containing washing solution through a sand-water separator to obtain a second lithium-containing solution and the lithium-containing waste residue, and the first lithium-containing solution and the second lithium-containing solution are mixed to obtain the lithium-containing solution.

7. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 6, characterized in that: In the step S301: a screw conveying device is used to perform multi-stage screw conveying processing on the battery crushed material; Among them, the spiral conveying equipment includes a spiral silo and a loading spiral conveyor belt connected to the spiral silo; the spiral silo is located inside the sound insulation cover and is connected to the unloading port of the multi-axis shredder, and one end of the loading spiral conveyor belt is connected to the top feeding port of the mixing barrel.

8. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 6, characterized in that: In the step S301: the acidic solution is sulfuric acid or hydrochloric acid, and the pH value of the lithium-containing washing solution is 6-7.

9. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 6, characterized in that: After the step S30 is completed, the method further includes: preparing battery-grade lithium carbonate from the lithium-containing solution by a sodium carbonate precipitation method.

10. The safe crushing and efficient separation method of lithium thionyl chloride batteries according to claim 1, characterized in that: In the step S40: the magnetic field intensity of the magnetic separation treatment is 9000GS~12000GS.

Images