Improved lithium battery recovery process

Abstract

The present disclosure relates to a process of comminuting a lithium battery. Lithium batteries are comminuted and quenched with a comminution liquid in a comminution compartment to safely discharge the batteries and produce comminuted battery residues and a liquid including an organic compound and a lithium compound. At least a portion of the liquid is separated from the comminuted battery residue to obtain a separated liquid containing a low flash point solvent and a high flash point solvent. A recovered comminuted liquid is produced from the separation liquid by removing at least a portion of the low flash point solvent, and / or the concentration of the high flash point solvent in the recovered comminuted liquid is increased to increase the flash point of the recovered comminuted liquid as compared to the comminuted liquid in the comminution compartment. The recovered pulverizing liquid is supplied to the pulverizing compartment to replace at least a portion of the pulverizing liquid.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 364,004, filed on May 2, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure generally relates to a process for recycling lithium batteries and a black substance obtained from the process. Background Art

[0004] As the world tries to move away from hydrocarbon-based energy sources, the popularity of lithium batteries has increased. There are a variety of lithium batteries available in the market, most of which belong to the following types: LFP (lithium iron phosphate), LCO (lithium cobalt oxide), LMO (lithium manganese oxide), NMC (lithium nickel manganese cobalt oxide), NCA (lithium nickel cobalt aluminum oxide), NCMA (nickel cobalt manganese aluminum oxide), and LTO (lithium titanate oxide). The above names describe the active materials in each of the different lithium battery types. Specifically, in the automotive industry, the use of lithium batteries is increasing. Electric vehicles are expected to occupy an increasing share of the automotive market. However, most lithium batteries are recycled in a way that has a significant impact on the environment and many valuable materials cannot be recovered. The supply of materials such as lithium, nickel, and cobalt used to manufacture lithium batteries is expected to be at risk in the near future, and alternative sources of these materials must be used to ensure that the cost of lithium batteries is affordable. Recycling batteries at the end of their life and substandard materials used to manufacture lithium batteries will play an important role in reducing the scarcity of these key materials. Recycling is also necessary to have a positive environmental impact on the use of electric vehicles, as the mining of raw materials for battery components places a great burden on the environment.

[0005] In WO2019060996 an innovative lithium recovery process is described, in which lithium batteries are crushed and the residues are immersed in an organic solvent. The process advantageously allows the crushing of lithium batteries without a previous step of discharging the batteries. Furthermore, the process can process all cathode components of lithium batteries available on the market and can be implemented in factories that also process all forms of battery packs (including metal and / or plastic casings and supports) to limit manual disassembly.

[0006] However, further improvements are needed to reduce operating costs, increase the yield obtained and further improve the safety of the recovery process. Summary of the invention

[0007] In one aspect, a process for crushing a lithium battery is provided, comprising: crushing and quenching a lithium battery with a crushing liquid in a crushing compartment to safely discharge the battery and produce a crushed battery residue and a liquid including an organic compound and a lithium compound; separating at least a portion of the liquid from the crushed battery residue to obtain a separated liquid, the separated liquid including a low flash point solvent and a high flash point solvent; producing a recovered crushed liquid from the separated liquid by removing at least a portion of the low flash point solvent, and / or increasing the concentration of the high flash point solvent in the recovered crushed liquid to increase the flash point of the recovered crushed liquid compared to the flash point of the crushed liquid in the crushing compartment; and supplying the recovered crushed liquid to the crushing compartment to replace at least a portion of the crushed liquid. In some embodiments, the process further comprises: separating the crushed battery residue after crushing and quenching, and also separating black matter from the liquid. In some embodiments, the process further comprises: separating the entrained low flash point solution from the crushed battery residue by drying and / or sinking and floating operations to increase the concentration of the high flash point solvent and reduce the flammability of the crushed battery residue.

[0008] In one aspect, a process for recycling lithium batteries is provided, comprising the following steps: crushing and quenching the lithium batteries with a crushing liquid in a crushing compartment to safely discharge the batteries and produce crushed battery residues, black substances, and a liquid comprising organic compounds and lithium compounds; separating at least a portion of the liquid from the crushed battery residues to obtain a separated liquid, the separated liquid comprising a low flash point solvent and a high flash point solvent; producing a recovered crushed liquid from the separated liquid by removing at least a portion of the low flash point solvent, and / or increasing the concentration of the high flash point solvent in the recovered crushed liquid to increase the flash point of the recovered crushed liquid compared to the flash point of the crushed liquid in the crushing compartment; supplying the recovered crushed liquid to the crushing compartment to replace at least a portion of the crushed liquid; separating the entrained low flash point liquid from the crushed battery residue; separating the crushed battery residue, and also separating the black substance from the liquid; the slurry comprising: removing the soluble metal ions and the non-percolating material; mixing the black material with an acid to produce a slurry, and percolating the slurry to produce a percolate comprising soluble metal ions and non-percolating material; filtering the percolate to remove the non-percolating material from the percolate; optionally feeding the percolate to a sulfide precipitation tank to remove ionic copper impurities from the percolate; removing iron and aluminum from the percolate; mixing the percolate with a first organic extraction solvent to produce an aqueous raffinate containing cobalt, nickel and lithium and an organic phase containing manganese; mixing the raffinate with a second organic extraction solvent to produce a second aqueous raffinate containing nickel and lithium and an organic phase containing cobalt; increasing the pH of the second aqueous raffinate phase to a pH between 9.5 and 12 to precipitate nickel from the aqueous phase and leave lithium in the aqueous solution; crystallizing sodium sulfate from the aqueous phase containing lithium to produce a clear solution containing lithium and sodium sulfate crystals; and recovering lithium from the clear solution. In some embodiments, separation of entrained low-flash point liquid from pulverized battery residue is performed by drying and / or sink-float operation, and preferably sink-float operation.

[0009] In some embodiments of the present process, the process further comprises: adding a high flash point solvent in the sinking and floating operation to obtain a crushed battery residue with reduced flammability and improve the recovery efficiency of the black matter. In some embodiments, the high flash point solvent is selected from an aqueous phase, a glycol or a cyclic carbonate. In some embodiments, the high flash point solvent is selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), propylene glycol (PG), ethylene glycol (EG), vinylene carbonate (VC), water and a combination thereof. In some embodiments, wherein the step of increasing the concentration of the high flash point solvent comprises: increasing the relative amount of the high flash point solvent and the low flash point solvent in the recovered crushed liquid. In some embodiments, the step of increasing the concentration of the high flash point solvent comprises: adding a certain amount of high flash point solvent to the recovered crushed liquid. In some embodiments, the process further comprises: removing part of the crushed liquid in the crushing compartment and using the part of the crushed liquid in the step of producing the recovered crushed liquid. In some embodiments, the process further comprises: removing a second portion of the crushed liquid in the crushing compartment; producing a second recovered crushed liquid from the second portion of the crushed liquid by removing at least a portion of the low flash point solvent, and increasing the concentration of the second high flash point solvent in the second recovered crushed liquid to increase the flash point of the second recovered crushed liquid; and supplying the second recovered crushed liquid to the crushing compartment. In some embodiments, the flash point of the recovered crushed liquid is greater than 38°C. In some embodiments, the crushing and quenching steps are performed at a temperature of less than 40°C. In some embodiments, the step of removing the low flash point liquid comprises decantation, distillation, activated carbon extraction, filtration and / or liquid-liquid extraction. In some embodiments, the step of removing the low flash point solvent is a decantation step, which comprises adding one or more of Na2SO4, K2SO4, Li2SO4, NaCl, sodium potassium tartrate (NaK-tartrate), sodium citrate (Na3-citrate), Na2FPO3, NaH2PO4, K2HPO4, Na2S2O3 and (NH4)2SO4. In some embodiments, the salt is sodium sulfate. In some embodiments, the low flash point liquid comprises a linear carbonate compound. In some embodiments, the separated high flash point solvent is recycled into the recovered crushed liquid. In some embodiments, the crushed liquid comprises a sufficient amount of aqueous phase to neutralize metallic Li into LiOH. In some embodiments, the hydrogen level in the exhaust gas from the crushing compartment is used to control the relative supply of the crushed liquid to the battery containing lithium metal. In some embodiments, the residual hydrogen generated by neutralizing Li into LiOH is reused or separated. In some embodiments, the recovered crushed liquid is cooled to control the temperature of the battery during crushing. In some embodiments, at least 50% of the F in the crushed liquid exists in the form of PF6. In some embodiments, selective diafiltration is performed before the diafiltration step, followed by a magnetic separation step to recover the iron phosphate product alone and produce a lithium-rich stream.

[0010] A black substance obtained by the process of the present disclosure is provided. A black substance is also provided, comprising: Mn, Ni, Co, Li, LiPF6, non-permeable fluorine compounds, graphite, oxides, and unavoidable impurities. In some embodiments, the black substance also includes moisture, which includes linear organic solvents and cyclic organic solvents and water. In some embodiments, LiPF6 is present in the moisture. In some embodiments, the non-permeable fluorine compound is polyvinylidene fluoride (PVDF). In some embodiments, the black substance does not contain metallic Li. In some embodiments, the black substance also includes plastic. In some embodiments, the moisture also includes glycols and alcohols. In some embodiments, the black substance has a pH of 5 or above. In some embodiments, the black substance includes particles having an average particle size greater than 50 microns.

[0011] After reading this disclosure, those skilled in the art will recognize many further features and combinations thereof related to the present improvements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Separate steps of processes covered herein and according to embodiments are schematically shown.

[0013] Figure 2 The electromechanical separation steps of a process covered herein and according to an embodiment are schematically illustrated.

[0014] Figure 3 The hydrometallurgical processing steps of the processes according to embodiments covered herein are schematically illustrated.

[0015] Figure 4 Schematically illustrated are various metal separation steps following a solvent extraction step as contemplated herein, according to embodiments.

[0016] Figure 5 Shown are thermogravimetric analyses of a black material obtained according to the present disclosure and a comparative control obtained using a conventional heat treatment process.

[0017] Figure 6 is a graph showing particle size distribution of a black substance according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0018] The process described herein is designed to be able to process all cathode compositions of lithium batteries available on the market. The process described herein can be implemented in a factory that can also process all forms of battery packs, including plastic and / or metal casings and supports to limit manual disassembly. Battery types that can be processed or recycled using the process described herein include, but are not limited to, LFP, LCO, LMO, NMC, NCA, NCMA, LTO, and NiMH.

[0019] Used batteries reaching the end of their useful life may have different compositions. The cathode is usually made of lithium metal oxide, where the metal portion is made of a mixture of cobalt, nickel and manganese. In some cases, the cathode may include only one or two of cobalt, nickel and manganese. Other cathode compositions, such as lithium iron phosphate, can also be processed. The anode is usually made of graphite or graphite mixed with silicon, but can also be composed of metallic lithium. The electrolyte can be a liquid solvent, usually a mixture of aliphatic and cyclic carbonates with dissolved lithium salts, or it can be a solid, such as a lithium-based solid electrolyte, a polymer solid electrolyte or other solid electrolyte.

[0020] A process for recycling lithium batteries is provided, comprising the steps of crushing the lithium batteries and quenching the lithium batteries and residues with a crushing liquid to safely discharge the batteries in a crushing compartment, and producing crushed battery residues and a liquid including an organic compound and a lithium compound. In some embodiments, the crushing compartment can be divided into two consecutive crushing stages, gradually reducing the size of the battery. The lithium compound can be a salt, such as lithium hexafluorophosphate (LiPF6) or lithium bis(trifluoromethane)sulfonyl imide (LiTFSi), or can be in a form other than a salt, such as any lithium form present in the battery. The most common form of lithium in a battery is the cathode active material or the anode of a lithium metal battery. If the battery is charged, the lithium initially present in the cathode material will be inserted into the graphite from the anode and can therefore be considered similar to metallic lithium. The battery typically contains one or more solvents selected from dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), ethylene carbonate (EC) and vinylene carbonate (VC). Thus, organic solvents include linear organic compounds (DMC, EMC, DEC) and cyclic organic compounds (PC, EC, and VC). Over time, for example in a continuous operation, the concentration of cyclic organic solvents may decrease relative to the concentration of linear organic compounds because the cyclic organic compounds are degraded and / or not recycled back into the pulverizing compartment. Moreover, in some cases, solvents (e.g., linear organic compounds and cyclic organic compounds) may accumulate over time. The accumulation of linear organic compounds may cause the flash point of the pulverizing liquid in the pulverizing compartment to decrease, which may increase operational risks.

[0021] The present disclosure advantageously reclaims a recovered pulverized liquid having an increased flash point compared to the pulverized liquid in the pulverizing compartment. This allows the overall flash point of the pulverized liquid to remain above the risk level. In some embodiments, the flash point of the pulverized liquid in the pulverizing compartment remains above 38°C, preferably above 39°C, more preferably above 40°C. In some embodiments, the recovery described herein may be discontinuously operated. The flash point of the pulverized liquid may be monitored, and only when it drops below a predetermined threshold, the present recovery process may be performed to increase the flash point of the pulverized liquid. In some embodiments, the threshold may be lower than 40°C, lower than 39°C, or lower than 38°C.

[0022] Other advantages of the present process, which will be described in further detail herein below, include reduction of required energy-intensive heating steps (e.g., no combustion or pyrolysis at 500°C or higher) and reduction of the associated potential formation of hazardous products, reduction of impurities obtained in the black mass, neutralization of metallic Li and optional recovery of lithium salts.

[0023] refer to Figure 1, a process for recycling crushing liquid to a crushing compartment is provided. A lithium battery can be received 1 and the lithium battery may or may not be pre-discharged and / or disassembled. Therefore, in some embodiments, there is still some charge left in the waste battery. If the internal components of the rechargeable battery are exposed to moisture contained in the surrounding air, an exothermic reaction occurs, which produces hydrogen. This leads to a serious risk of hydrogen combustion and an increased risk of thermal runaway. In order to minimize the risk of combustion, the entire waste battery is crushed by quenching 2 in an inert atmosphere and in continuous contact with the crushing liquid to absorb the heat generated by the battery discharge and neutralize any metallic lithium present in the battery, whether it is from the residual charge remaining in the battery or from the metallic lithium present in the lithium metal battery. Quenching can include spraying the crushing liquid on the battery being crushed in the crushing compartment. In some embodiments, the crushing liquid may accumulate between the two stages of the crushing compartment and continue to wet the partially crushed battery. Due to the small size, the crushed fragments produced can eventually be completely immersed in the crushing liquid deposited at the bottom of the crushing compartment. However, quenching should not be interpreted as immersion because the entire battery itself is not immersed. The crushing liquid is used to dissolve and extract the electrolyte salts contained in the battery, such as lithium hexafluorophosphate (LiPF6). The crushing liquid also allows the black matter (BM) to be separated from other solid battery components. The term "black matter" as used herein also refers to the concentrate of strategic materials. The crushing liquid can be miscible with the electrolyte solvent present in the battery cell. Therefore, then, the contact between the internal components of the battery and oxygen is limited. Moreover, if an exothermic reaction occurs, the crushing liquid will act as a heat sink, thereby reducing the operational danger. Under more severe exothermic conditions, the entire crushing compartment can be filled with crushing liquid and / or water to absorb heat and prevent the reaction from proceeding. In one embodiment, the crushing liquid is kept below 40°C, in other words, the crushing and quenching are carried out at a temperature below 40°C, preferably below 30°C, more preferably, even more preferably below 20°C, and in some cases at 10 to 15°C. In one embodiment, crushing 2 is performed until an average particle size of about 5 to 15 mm is obtained.

[0024] After pulverization 2, the pulverized battery residue and liquid undergo a separation step 3a to separate the liquid phase (i.e., the organic solvent with the suspended black matter) from the solid phase (i.e., the pulverized battery). The pulverized battery residue can be separated by screening, filtering, centrifugation or other suitable means. The liquid phase is also further separated 3b to obtain the black matter by separating the suspended black matter from the liquid phase.

[0025] The crushed battery residues often contain residual crushing solvent (i.e., wet crushed batteries) whose flash point may be lower than the flash point of the recycled crushing liquid described above, resulting in battery residue by-products that need to be transported or handled as hazardous materials, thereby reducing their value and additional costs invested in the recycling process. The amount of solvent remaining in the battery residue can be controlled via a separation step 10, which can be a sink-float 10 and / or a drying step 10. By adding a high flash point solvent to the sink-float operation and subjecting the crushed battery residue to the sink-float operation, not only can the different by-products be separated by the difference in their corresponding specific densities, but the potential flammability of the generated wet by-products (particularly light plastic by-products) can also be greatly reduced. Removing the entrained solvent from the crushed battery residue can improve the ease of handling the downstream by-products. Then, their handling and transportation are safer, and, in addition, they also have a higher purity and, therefore, a higher economic value. A second benefit of adding a high flash point solvent to the sink-float is that the excess solution volume containing a small portion of the black matter washed out of the battery residue is recycled back to the black matter separation step (see Figure 1 The arrow between separation 3a and 3b in the drying step) is used to improve the overall black matter recovery rate. In some embodiments, drying 10 can be performed at a temperature suitable for separating a specific group of compounds with similar boiling points. For example, low flash point solvents can be separated at a temperature of 60 to 130°C. On the other hand, in order to separate high flash point solvents, a temperature of 150 to 300°C can be used. Vacuum drying can also be used to obtain similar separation effects at lower temperatures. The same principle can be applied to the drying step to selectively evaporate and recover the crushed liquid. Similarly, low flash point solvents can be extracted and only high flash point solvents can be selectively recovered. Then, the crushed liquid recovered from sinking and / or drying 10 can be reused in separation step 3b or crushing step 2. In order to avoid the melting of lightweight plastics in the oven of the drying step 10, the lightweight plastics can be separated before applying heating, for example, by sinking / floating separation technology, entrainment of lightweight materials like zigzag technology, or by wet grinding, and the unground plastic film can be separated by screening. Therefore, in some embodiments, both drying and sinking / floating are performed in step 10.

[0026] Then, the pulverized liquid is subjected to a separation step to remove at least a portion of the lower flash point solvent (e.g., linear organic solvent). Since the linear organic solvent has a low flash point temperature, removing the linear organic solvent increases the flash point of the entire mixture. In some embodiments, removal 4 can be performed by activated carbon extraction, decantation, liquid-liquid extraction (e.g., organic separation), filtration and / or distillation. In a preferred embodiment, removal 4 is performed by activated carbon extraction, decantation and / or liquid-liquid extraction. Decantation provides a process for separating the high flash point phase and the low flash point phase by the difference in their respective densities. This allows some low flash point solution to be removed from the loop, thereby increasing the relative proportion of the high flash point solvent recovered to the pulverizing step. It has been found that by adding soluble salts such as Na2SO4, K2SO4, Li2SO4, NaCl, sodium potassium tartrate (NaK-tartrate), sodium citrate (Na3-citrate), Na2FPO3, NaH2PO4, K2HPO4, Na2S2O3, (NH4)2SO4 or many other soluble salts in the pulverized liquid. Information on the ionic strength of these salts is described in Hyde, AM, Zultanski, SL, Waldman, JH, Zhong, YL, Shevlin, M., & Peng, F. (2017), General principles and strategies for salting-out informed by the Hofmeister series. Organic Process Research & Development, 21(9), 1355-1370. Increasing the ionic strength of the mill liquor increases the number of low flash point compounds, which are removed and transferred to a heavier phase in the decanting apparatus, which can then be removed from the mill liquor circuit and replaced with a higher flash point solvent. A salt concentration of 5% to 10% was found to be sufficient. As discussed above, the mill liquor contained various organics, but was also found to contain LiPF6. This is because there was enough organic matter in the mill liquor to dissolve the LiPF6 in the organic matter without decomposing it on contact with water. By ion chromatography, approximately 75% of the F in the mill liquor was found to be in the form of LiPF6. Thus, in some embodiments, at least 50%, preferably at least 60%, more preferably at least 70% of the F in the crushed liquid is in the form of LiPF6. Thus, this valuable compound can be optionally recovered from the extraction solvent eliminated from the circuit in the decantation operation, for example, by distillation, crystallization and / or precipitation. This further improves the closed-loop recycling opportunities of the battery recycling process.

[0027] In one embodiment, PC, VC and EC can be regenerated by distillation of organic solvents and can be separated from linear solvents. EC and / or VC can be separated by converting them into solids by cooling, and can be re-melted and reintroduced as part of the recycled crushed liquid to increase the flash point of the crushed liquid. In some embodiments, PC is preferred over EC because PC remains liquid under operating conditions.

[0028] Since the recycled crushing liquid has a higher flash point than the crushing liquid, it has the advantage of increasing the flash point of the crushing liquid when it is added to the crushing compartment. In some embodiments, the recycled crushing liquid has a flash point of at least 39°C, at least 40°C, at least 41°C, at least 42°C, at least 43°C, at least 44°C, or at least 45°C.

[0029] In addition, in some embodiments, it is desirable to control the temperature in the crushing compartment according to the battery discharge to prevent thermal runaway and to prevent the formation of fluorinated organic gases or other combustion gases. Therefore, in some embodiments, the recovered crushing liquid can be cooled and sprayed in the crushing compartment to control the temperature of the battery during crushing and limit its reactivity. In some embodiments, a cooling jacket, an external cooling device, or the like can be used to maintain the crushing liquid inside the crushing compartment at a temperature below 40°C, for example 10 to 15°C.

[0030] The crushing liquid may include linear organic solvents, such as DMC, EMC and DEC, which typically have a flash point between 17 and 33°C. These linear organic solvents are referred to herein as low flash point solvents. The crushing liquid may also include cyclic organic solvents with much higher flash points, which are in the range of 65 to 150°C, preferably 135 to 150°C. These cyclic organic solvents are referred to herein as high flash point solvents. The following table summarizes the properties of the 6 main organic solvents present in the lithium battery and therefore in the crushing liquid of the present disclosure, as well as other organic compounds that may be present in the crushing liquid.

[0031] Table 1. Properties of the compound

[0032]

[0033] As can be seen from the above table, increasing the relative concentration of PC, EC and VC with respect to DMC, DEC and EMC will increase the flash point of the recovered crushed liquid. PC, VC and EC are particularly advantageous because they are already present in the crushed liquid and can be simply reused in the recovered crushed liquid. However, there are other solvents (referred to as high flash point solvents herein) that can play a role in improving the flash point, and such solvents can be cyclic carbonate compounds, glycol compounds (such as ethylene glycol and propylene glycol) and water. Therefore, in some embodiments, a high flash point solvent is added 5 to the recovered crushed liquid to improve its flash point. The added high flash point solvent can be a compound (such as PC, VC and EC) that already exists in the crushed liquid but has a too low concentration. The addition can be carried out from an external source and therefore cannot be considered to be "recovered" from the process interior. In another embodiment, the added high flash point solvent can be recovered from the dryer 10.

[0034] Additionally or alternatively, other high flash point solvents such as dimethyl sulfoxide (DMSO) and N-methylpyrrolidone (NMP) may be used to increase the flash point of the recovery solution. They have the additional advantage of dissolving the PVDF binder and enhancing the release of graphite and cathode active materials, which promotes the extraction and separation of graphite and therefore also improves the percolation kinetics. In some optional embodiments, a portion of the crushing liquid from the crushing compartment may be retrieved from the crushing compartment and subjected to removal 4 to increase its flash point. In some embodiments, the crushing solvent may be subjected to a second separate recovery cycle independent of the removal 4 step. The second recovery cycle has the same steps as described above to increase the flash point. The second separate recovery cycle may also receive additional high flash point solvent 5. In some embodiments, the second separate recovery cycle may replace the recovery cycle described above, but is preferably optionally performed in addition thereto.

[0035] In some embodiments, the recycling crushing liquid includes water. The advantage of adding water or the presence of water in the recycling crushing liquid is that water can potentially significantly increase the flash point. Indeed, water has a strong cooling power (thermal power). In addition, the presence of water creates organic water surface tension, which can improve cooling. Other products designed to promote surface wetting and improve the control of fire spread through its increased heat capacity and by promoting the formation of a spherical mixture including a flammable solvent can also be included in the recycling crushing liquid. F500 TM An encapsulant is one example of such a product. Water also allows for the recovery of metallic lithium by dissolving the metallic lithium (which reacts with water to form LiOH). Additionally, water can decompose LiPF6 to dissolve Li. This increases the overall lithium recovery rate.

[0036] Using current dry methods of shredding lithium batteries requires extensive sorting of the lithium batteries prior to shredding in order to separate the batteries made of lithium metal anodes. If such batteries are shredded using dry methods, metallic lithium will still be present in the BM after shredding. Subsequent contact of the BM containing metallic lithium with water or water vapor can initiate a local exothermic reaction of lithium conversion to LiOH, which will generate hydrogen. This reaction is known to be hazardous. Therefore, the presence of unreacted metallic lithium in lithium metal battery shredding is a major source of fire initiation in the conventional recycling industry.

[0037] Thus, when carried out in an inert atmosphere, the present process can be used to pulverize and neutralize rechargeable batteries or lithium metal batteries in a single step by providing a sufficient amount of water to the metallic lithium during the pulverization process so as to convert all the metallic lithium into LiOH. Thus, by ensuring proper control of the battery temperature during pulverization and by properly managing the hydrogen generated by neutralizing the metallic lithium with a recovered pulverizing solution, the present process enables safe operation during pulverization. In some embodiments, the hydrogen level in the exhaust gas of the pulverizing compartment can be used to control the relative supply of pulverizing liquid to the battery containing lithium metal. An increase in hydrogen content will increase the risk and will indicate that the inlet amount of the battery containing lithium metal will be reduced. The hydrogen generated during neutralization is separated using a pressure swing absorber or other techniques known to those skilled in the art. The separated hydrogen can be reused in different applications, such as steam generation or, for example, as an energy source in a gas processing burner.

[0038]

[0039] Therefore, in some embodiments, the components of the recycled crushed liquid include DMC, EMC, DEC, EC, PC, VC, LiPF6, ethylene glycol (EG), propylene glycol (PG), methanol, ethanol and water. In some embodiments, the recycled organic solvent does not include glycols, such as PG and EG, and does not include water. In some embodiments, the crushed liquid includes 5 to 70 wt% of cyclic organic compounds, 0 to 60 wt% of linear organic compounds, and the balance is water. Exemplary compositions of recycled crushing liquid are up to 35 wt%, up to 40 wt%, up to 45 wt%, up to 50 wt%, up to 55 wt%, up to 60 wt%, up to 65 wt%, up to 70 wt%, up to 75 wt% of any combination of DMC, EMC and DEC, 5 to 60 wt%, 10 to 60 wt%, 10 to 50 wt%, 15 to 60 wt%, 15 to 45 wt%, 20 to 45 wt%, 25 to 45 wt%, 30 to 45 wt% of PC, VC and / or EC. In some embodiments, the crushing liquid is completely organic (i.e., free of water) and includes up to two-thirds of linear organic compounds (e.g., DMC, EMC and DEC) and one-third of cyclic organic compounds (e.g., EC, VC and PC) to about half and half. Thus, in some embodiments, the weight ratio of linear organic compounds to cyclic organic compounds is from about 2:1 to about 1:1. In some embodiments, it may be advantageous to add external EC, VC and / or PC. In some embodiments, separation techniques (such as decantation) may be used to concentrate, separate or increase the concentration of high flash point solvents (such as EC, VC and PC). Thus, the recovered crushed liquid may include linear organic compounds (DMC, EMC, and / or DEC) and cyclic organic compounds (EC, VC and PC), with a linear to cyclic weight ratio of at least 1:0.5, at least 1:1, at least 1:2, at least 1:2.5, at least 1:3, at least 1:3.5 and at least 1:4, and in some cases 0.9:1.1 to 1.1:0.9. In such an embodiment, the recovered organic solvent may be free of water or include less than 1 wt% water.

[0040] In some embodiments, the recycled crushed liquid optionally includes up to 90 wt % water. Water can be added to the organic solvent described above. In some embodiments, when water is added to the recycled organic solvent (see Figure 1In step 5), the recovered crushed liquid may include water in a concentration of up to 1 wt%, up to 5 wt%, up to 10 wt%, up to 20 wt%, up to 30 wt%, up to 40 wt%, up to 50 wt%, up to 60 wt%, up to 70 wt%, up to 80 wt%, up to 85 wt%, up to 90 wt%, up to 95 wt%, up to 98 wt% or entirely water.

[0041] In some embodiments, the recycled crushed liquid comprises PC at a concentration of 5 to 95 wt %, 10 to 80 wt %, 15 to 75 wt %, 15 to 60 wt %, or 20 to 35 wt %.

[0042] The portion of the pulverized liquid not recycled back to the pulverizing compartment may be subjected to one or more distillations to purify the organic solvent. In one embodiment, three distillation towers 7, 8, 9 are used, such as Figure 1 As shown. The first tower 7 can be operated at about 90°C to obtain battery-grade dimethyl carbonate (DMC) in the overhead distillate. The second tower 8 can be supplied with the bottoms of the first tower, which generally contain ethyl methyl carbonate (EMC), diethyl carbonate (DEC), cyclic carbonates (e.g., EC, VC, PC, or a combination thereof). The second tower can be operated at about 107°C to obtain battery-grade ethyl methyl carbonate (EMC) in the overhead distillate. The bottoms of the second tower can be supplied to the third tower 9. The third tower can be operated at about 126°C to obtain battery-grade diethyl carbonate (DEC) in the overhead distillate, and obtain EC, VC, PC, or a combination thereof from the bottoms.

[0043] After sinking and / or drying 10, the remaining battery residue is fed to a magnetic separator 11 in order to separate the iron flakes and particles magnetically retained by the magnet from other solids. Figure 2 , the non-magnetic battery residue undergoes a crushing step 12, or the average particle size is reduced to a smaller average particle size, for example between 0.1 and 4 mm. Different crushing and grinding unit operations can be used, such as but not limited to hammer mills, impact crushers, granulators or turbo mills. Plastic film, rubber or other soft products will form the upper range of the particle size distribution. Aluminum is crushed into round aluminum (such as spheres), and the size of copper foil is reduced.

[0044] In an embodiment, the outlet of the crusher is then screened at about 1 mm 13. Optionally, the oversized fraction is fed to a second grinding using equipment such as, but not limited to, for example, a high shear mixer or a cutting mill.

[0045] The coarse particles containing mainly plastic, copper and aluminum are then fed to a separator 15 where the aluminum and copper particles are extracted. The remaining plastic can be sent to a recycling facility. The aluminum and copper particles can be separated by density classification 16 using equipment such as, but not limited to, weight separation or air classifiers. The fine particles collected from multiple suction points include aluminum, copper, other metals and black powder (graphite + CAM).

[0046] See also Figure 3 In the percolation tank 17, the black material is mixed with sulfuric acid and water to obtain a black material slurry, the concentration of acidic material in the liquid phase of the slurry is between 5% and 30%, and the operating point is about 17%. The slurry is stirred at about 60 to 95°C for 1 to 4 hours, and the solid concentration is 50 to 250 kg of solids per cubic meter of acid solution. Typical operation should be about 60 to 70°C, 200 kg / m 3 The reaction was carried out for 3 hours at a solid concentration of 1.547 W / m2.

[0047] In some embodiments, selective diafiltration is performed prior to the diafiltration step 17. After the selective diafiltration, a magnetic separation step may be performed to recover the iron phosphate product, thereby producing a lithium-rich stream.

[0048] A reducing agent may also be added to the reaction tank to assist in the infiltration of the transition metals, such as, but not limited to, hydrogen peroxide (H2O2), manganese oxide (MnO2), or aluminum powder (Al), or other reducing elements known in the art. Typical working concentrations of the reducing agent may be 0 to 30% w / w of the solution for H2O2, 0 to 5% w / w for MnO2, and 0 to 5% w / w for Al. The transition metals (Co, Ni, Mn) in the slurry are reduced or oxidized to a divalent (2+) oxidation state, in which they are more susceptible to infiltration. Infiltration of the metal oxide slurry produces a leachate of metal sulfates, which is filtered out of the solid, non-infiltrated material. In some embodiments, infiltration 17 may be performed in two infiltration steps. In one embodiment, the black mass is heated to about 550°C before the first infiltration or between the two infiltration steps to remove the plastic polyvinylidene fluoride (PVDF) and styrene butadiene (SBR), and release graphite and cathode active material (CAM).

[0049] In the case of percolation in two steps, the graphite cake obtained after the first percolation step (which still contains some valuable black matter) is suspended back into a liquid, for example a liquid similar to the aqueous solution from the percolation step. It is also a mixture of sulfuric acid and a reducing agent, such as but not limited to hydrogen peroxide (H2O2), manganese dioxide (MnO2) or aluminum powder (Al). This solution dissolves the remaining metals in the graphite. The graphite is then filtered 18 and then washed 19 with water. The graphite cake is then fed to a furnace 20 operating between 200 and 800°C, preferably at 600°C, to evaporate the remaining plastic, binder and carbon black and dry the graphite. Drying 20 removes moisture and solvents and can optionally be carried out under vacuum or low pressure to prevent solvent reactions, or under inert conditions, or under nitrogen or air.

[0050] The filtrate containing lithium, cobalt, nickel, manganese, iron, aluminum and copper as sulfates (Li2SO4, CoSO4, NiSO4, MnSO4, Fe2(SO4)3, Al2(SO4)3, CuSO4) is sent for further purification, such as by cementation, hydroxide purification, electrowinning, etc. Optionally, the copper can be recovered by removing the ionic copper from the solution using a sulfide precipitation tank 21, or it can be directed to a neutralization / purification stage. Other methods of precipitating or isolating copper, such as cementation or ion exchange, can also be used. The copper impurities can be removed by reacting with sulfur ions (S " ) to precipitate. The sulfide ion source can be any sulfide compound, such as, but not limited to, sodium sulfide (Na2S) or bubbling hydrogen sulfide (H2S). At a pH below 2 and a temperature between 40 and 80°C, the sulfide will selectively combine with copper to form water-insoluble copper sulfide (CuS). Depending on the concentration of copper ions in the solution, the concentration of Na2S can vary between 2 and 5 kg of Na2S per kg of diafiltrated battery residue, and the retention time is 15 minutes to 1 hour. The precipitate will be eliminated from the main process line by filtration and sold.

[0051]

[0052] The leachate is then neutralized 22 to a pH between 3.5 and 5.8 by adding sodium hydroxide (NaOH) to precipitate the remaining copper, iron and aluminum, which will form water-insoluble hydroxides (Cu(OH)2, Al(OH)3, Fe(OH)3). The precipitate takes 30 minutes to 2 hours to stabilize, with an expected reaction time of 1 hour. The precipitate is filtered out of the process.

[0053]

[0054]

[0055]

[0056] At this point in the process, different pathways can be used to separate the Mn, Co, and Ni transition metal elements from each other. Figure 4 As shown, one approach is to perform a solvent extraction step for each of Mn and Co (23 and 27, respectively). Figure 4 , the filtrate from the hydroxide precipitation stage 22 is sent to a first solvent extraction process for Mn separation 23. This solution is mixed with an organic extraction solvent (extractant) dissolved in a petroleum-based reagent (diluent). The concentration of the extractant in the diluent can vary between 2 and 40 mass percent, with more typical values ​​between 15% and 35%. Using an aqueous solution with a pH between 3 and 5, Mn will be extracted from the organic phase, while cobalt, nickel, lithium and sodium will remain in the aqueous raffinate phase.

[0057] To carry out the solvent extraction process, mixer-settlers, extraction columns such as pulse columns, columns with internal stirring using rotating impellers, reciprocating plate extraction columns, hollow fiber membranes, etc. can be used. For the above-mentioned equipment, the lighter organic phase is usually pumped out from the top of the settling zone (no longer mixed), and the heavier aqueous phase is discharged from the bottom of the equipment through another buffer, where sufficient time is given for separation by decantation. The organic phase is then sent to the washing and stripping stage, and the aqueous phase (raffinate) is sent for further treatment.

[0058] In the washing stage 24, the organic phase is contacted with an aqueous solution having a pH of about 2 to 4. The two phases are mixed and separated in a similar apparatus as described above. The aqueous solution is returned and mixed with the solvent extraction inlet.

[0059] In the stripping stage 25, the organic phase loaded with Mn is contacted with an aqueous solution containing sulfuric acid having a pH between 0 and 2 to strip manganese. Again, similar equipment as described above is used here to mix and separate the two phases. Optionally, the process includes an additional washing stage to further regenerate the organic solvent. The washed organic solvent is then fed back to the extraction stage. The temperature of all stages is maintained at a temperature between 35°C and 60°C.

[0060] The stripping solution rich in Mn can then be further processed to recover valuable Mn compounds. Different Mn compounds can be produced, such as MnCO3, MnO2 or MnSO4. In the specific case of MnCO3, precipitation 26 can be performed. The solution leaving the tower is mixed with a carbonate source, such as Na2CO3. The precipitated MnCO3 is then filtered, washed and dried.

[0061] refer to Figure 4, the raffinate from the first solvent extraction process (which contains primarily cobalt, nickel and lithium) is mixed with a second organic extraction solvent (extractant) dissolved in a petroleum-based reagent (diluent) 27. The process for cobalt solvent extraction is similar to that described above for manganese, except that the extraction pH range is more typically 3.8 to 5.5, washing 28 is carried out at a pH of 2 to 4, stripping 29 is carried out at a pH < 2.5, and the temperature of all stages is maintained in the range of 50°C to 60°C.

[0062] The Co-rich stripping solution may be further processed to recover valuable Co compounds. One such technique is to process the stripping solution and, where a cobalt sulfate product is desired, send the solution to a crystallizer 30 and then filter and dry the solid CoSO4.7H2O product.

[0063] However, there are different approaches to separating the Mn, Co, and Ni transition metal compounds. It is also possible to use a single solvent extraction process to extract Mn and Co while leaving Ni in the aqueous raffinate. In such a case, the stripping solution may contain both Co and Mn, which must be separated from each other. If neutralized with sodium hydroxide, they will precipitate together, but since they have different standard reduction potentials (-0.28 V for cobalt and -1.18 V for manganese), they can be separated by an electrowinning process26. Cobalt will be plated on the cathode in its metallic form and then scraped off. Manganese will be oxidized to MnO2 and deposited on the anode. Cobalt electrowinning is accomplished using a monolithic electrolytic cell with a cobalt blank cathode and a DSA anode, where the current density is between 150 and 350 A / m 2 The voltage is between 2.7 and 5 V. The electrolyte is supplied at a pH between 2.5 and 5 at a temperature between 45 and 70°C. The electrode reaction is as follows:

[0064] cathode:

[0065]

[0066]

[0067] anode:

[0068]

[0069]

[0070] In some embodiments, as exemplified Figure 4As shown, after the solvent extraction step, the aqueous raffinate contains a large proportion of dissolved nickel sulfate (NiSO4), from which Ni can be recovered. This can be achieved by different methods, such as precipitation, ion exchange or solvent extraction. In one embodiment, hydroxide precipitation 31 is performed: the solution is heated to between 50 and 70°C, and the pH of the solution is increased to between 9.5 and 12, with an expected value of 10, by adding hydroxide 31 to the precipitate nickel hydroxide (Ni(OH)2). The precipitation takes 0.5 to 4 hours to complete, and the expected reaction time is 3 hours. The nickel hydroxide is filtered, washed, and redissolved in sulfuric acid solution, crystallized 32 at 50°C as α NiSO4.6H2O, filtered and dried 28 at 50°C, and it can be sold.

[0071] At this point in the process, the remaining aqueous solution contains significant proportions of sodium sulfate (Na2SO4) and lithium sulfate. Sodium sulfate is produced as a result of the neutralization of sulfuric acid with sodium hydroxide, which occurs during the precipitation of the hydroxide and other steps in the process. The high concentration of sodium sulfate, combined with the significant dependence of its solubility on temperature, makes it attractive for crystallization by cooling, whether surface cooling, flash cooling or other means. By cooling the neutralized leachate to between 0°C and 10°C, a larger proportion of the sodium sulfate is crystallized as decahydrate crystals, known as Glauber's salt (Na2SO4*10H2O)34. Removing the sodium sulfate in the form of hydrated crystals also has the benefit of concentrating the remaining lithium in the aqueous solution (mother liquor). The resulting crystals are fed to a centrifuge for dehydration and washing.

[0072]

[0073] If further application or use is desired, then the salt can be diluted with water and recrystallized into anhydrous form.

[0074] Due to the numerous purification steps upstream, the sodium sulfate crystals produced will have a high level of purity. The solution of the purified Na2SO4 salt can be suitable for recovery techniques such as, but not limited to, electrochemical salt decomposition (including electrodialysis, electrolysis, etc.). Prior to electrochemical treatment, the salt solution can also be subjected to a purification treatment (e.g., ion exchange) to remove such impurities. The electrolysis of sodium sulfate will produce sulfuric acid and sodium hydroxide, which are the main consumable reagents required for the process. This step will eliminate or reduce the need to supply fresh sulfuric acid and sodium hydroxide to the process.

[0075] The mother liquor from the sodium sulfate crystallizer contains a high concentration of lithium sulfate solution, and lithium needs to be extracted from the solution. This can be achieved by different processes, such as precipitation, crystallization or solvent extraction. In one embodiment, the solution from the sodium sulfate crystallizer is heated to a temperature between 80 and 100 ° C, and a carbonate ion source (CO3 2-The carbonate ion source may be a carbonate ion compound, such as sodium carbonate (Na2CO3), or may be a carbonate acid ion (HCO3) produced by passing CO2 gas. - ) or by a combination of the two. The carbonate ions react with the lithium ions to produce lithium carbonate (Li2CO3) 35, which is only slightly soluble in water. The precipitate is expected to take 30 minutes to 2 hours to stabilize, with an operating retention time of 1 hour. The precipitate is filtered and dried and sold as dry lithium carbonate. The filtrate solution contains lithium and is recovered in the process, for example to diafiltration 17.

[0076]

[0077] In one aspect of the present disclosure, a black material having reduced impurities and reduced organic content is provided. In some embodiments, the black material can be recovered before further reducing the size of the pulverized residue. In some embodiments, the black material has a higher proportion of cyclic organic solvents than linear organic solvents (embodiments of recycled organic solvents without water) compared to the proportions present in the battery. In some embodiments, the increased cyclic solvent and / or glycol content imparts higher thermal energy to the black material without providing the handling issues of linear solvents.

[0078] The filtration of the black matter usually produces a black matter filter cake, which can be washed to reduce the solvent concentration. The wet black matter is recovered and can be optionally dried to a level that maintains a sufficiently high humidity to prevent spontaneous reaction with aluminum and water. In some embodiments, the wet black matter (e.g., 30% humidity) is dried to obtain a dry black matter by removing water and light solvents. Drying can be, for example, flash drying. The presence of Li and F in the black matter can be in the form of a salt, such as, but not limited to, LiTFSi, PO3F, LiF, LiPF6, metallic Li, LiOH, LiHCO3, Li2CO3.

[0079] The composition of the black substance will vary based on the composition of the lithium battery provided at the beginning of the process. The black substance obtained by the present process has at least 5 wt% moisture, which includes at least linear organic solvents and cyclic organic solvents and water, Ni, Mn, Co, Li and non-leaching fluorine compounds, and the balance is graphite, oxides and unavoidable impurities. Moisture can be characterized by the presence of solvents, including linear organic solvents and cyclic organic solvents and water, and optional alcohols and glycols. The main components of moisture are usually linear organic solvents and cyclic organic solvents and water (totaling up to 80 wt% or more). Moisture can be present, for example, in a concentration of 5 to 20 wt%, 6 to 15 wt% or 7 to 10 wt%. The moisture in the black substance contains or originates from the crushing liquid of the process. As shown above and in Example 3 below, the crushing liquid contains LiPF6. This is a valuable compound, which can therefore also be present in the moisture of the black substance. In some embodiments, LiPF6 is present in a concentration of 0.03 to 0.25 wt% with respect to the total weight of the black substance. In some embodiments, the moisture of the black mass also includes lithium in the form of LiTFSi. The concentration of LiTFSi can also range from 0.03 to 0.25 wt%. In some embodiments, the black mass includes plastic and adhesive materials, such as polyvinylidene fluoride (PVDF), which can be considered as unavoidable impurities. In some embodiments, the ratio of organic solvent to water in the black mass is greater than 0.05. In some embodiments, the black mass is characterized by having a pH greater than 5. In some embodiments, the black mass includes an average particle size or D greater than 50, greater than 60, or greater than 100 microns. 50 The black matter may also include POF3 and LiF, which may be part of the moisture.

[0080] The presence of F in the BM as a non-leakable species (e.g. PVDF) rather than a percolatable species makes the BM less corrosive. This is an advantage of the present process, especially compared to other processes that carry out heat treatment or calcination. In such other processes, a much larger portion of the F in the BM is percolatable. Furthermore, in the BM obtained according to the present process, the F may be mainly comprised in graphite. The F present in the graphite is processed under dry conditions and therefore there is no risk of being percolatable and no risk of forming HF when in contact with water.

[0081] Although the obtained black substance is wet, it can be subjected to a drying step to remove at least a portion of the moisture. In some embodiments, drying is carried out at a temperature at which water and cyclic organic solvents are evaporated. In some embodiments, drying is carried out at a temperature at which water and linear organic solvents and cyclic organic solvents are evaporated. The drying temperature can be, for example, in the range of 90 to 180° C. When at least part or most of the moisture is dried, the LiPF6 present in the moisture remains in the black substance and is a material with recovery value. Due to the loss of solvent quality, the concentration of LiPF6 in the dried black substance will be relatively higher than that in the wet black substance. In some embodiments, the concentration of LiPF6 in the dried black substance can be 0.04 to 0.3 wt %.

[0082] Example 1 Thermogravimetric analysis (TGA) of black matter

[0083] TGA ( Figure 5 ). Three samples A to C were obtained using the process described above according to the present disclosure. The composition of the samples will vary depending on the type and composition of the batteries received by the recycling plant. The wet black material was subjected to TGA.

[0084] Table 2. Mass loss during TGA (in weight percent)

[0085]

[0086] Figure 5 The remaining mass after the mass loss shown in Table 2 corresponds to the remaining metals including Ni, Co and Mn.

[0087] Example 2 Analysis of battery residues before and after sinking and floating operations

[0088] Before performing step 10 of the sink and float operation (see Figure 1 ) and after this step, the moisture content of the battery residue obtained by the process of the present disclosure was analyzed (Table 3). This shows the moisture level of the crushed material (before and after the sinking and floating operation). The flammability risk can be evaluated based on the moisture level.

[0089] Table 3. Analysis of battery residues before and after sinking and floating

[0090]

[0091] Example 3 Presence of LiPF6 in the pulverized liquid

[0092] According to Figures 1 to 4The crushed liquid of the process was analyzed to determine the different forms of F in the crushed liquid. Four experiments with crushed liquids labeled 1 to 4 are shown in Table 4 below. The analysis of the different forms of F is also shown in Table 4.

[0093] Table 4. F content in crushed liquid (concentration unit is ppm)

[0094]

[0095] Example 4 F content released from BM during diafiltration

[0096] In order to evaluate the non-filterable F content of BM without heat treatment, three BMs were filtered and the F content was measured (Table 5). As can be seen from Table 5, without heat treatment, most of the F species remain in a non-filterable form (such as PVDF) and remain in the graphite. Therefore, it is a safer operation and removes F.

[0097] Table 5. F content in BM diafiltration

[0098]

[0099] Example 5 Recovery solution obtained from decantation with or without salt addition

[0100] An example of a pulverized solution was prepared by mixing 40 wt% of electrolyte collected from a lithium ion battery with 60 wt% of an aqueous solution. Analysis of the electrolyte before mixing gave the following concentrations of the low flash point solvent and the high flash point solvent.

[0101] Table 6. Initial electrolyte solution composition (wt%)

[0102]

[0103] The prepared solutions were fed to a decantation unit and in the first case pure water was added and the performance was investigated using a 10 wt% Na2SO4 solution. The separated heavy fractions in both cases contained a higher ratio of low flash point solvents (linear solvents DMC, EMC, DEC) to high flash point solvents (cyclic solvents EC) compared to the ratio in the incoming electrolyte solution, indicating that decantation is effective in removing more low flash point solvents and producing a recovered crushed liquid (light fraction A) containing a lower amount of low flash point solvents compared to the original mixture.

[0104] Furthermore, the addition of 10 wt% Na2SO4 aqueous solution to the exemplary solution instead of pure water resulted in a recovered crushed liquid (light fraction B) having a lower linear to cyclic ratio than pure water (light fraction A), thus resulting in a higher flash point of the salt-added solution.

[0105] Table 7.Results for heavy and light fractions

[0106]

[0107] Example 6 Black matter particle size distribution

[0108] The black material obtained according to the present disclosure (ie without any further heat treatment) was analyzed for particle size distribution. The D50 was found to be about 100 μm ( Figure 6 ).

[0109] The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. After reviewing this disclosure, those of ordinary skill in the art will recognize that the embodiments described herein may be changed without departing from the scope of the present technology. In view of this disclosure, those of ordinary skill in the art may implement further modifications that will fall within the scope of the present technology.

Claims

1. A process for crushing lithium batteries, include: pulverizing and quenching the lithium battery with a pulverizing liquid in a pulverizing compartment to safely discharge the battery and produce a pulverized battery residue and a liquid including an organic compound and a lithium compound; separating at least a portion of the liquid from the pulverized battery residue to obtain a separated liquid, the separated liquid comprising a low flash point solvent and a high flash point solvent; producing a recovered pulverized liquid from the separated liquid by removing at least a portion of the low flash point solvent, and / or increasing the concentration of the high flash point solvent in the recovered pulverized liquid to increase the flash point of the recovered pulverized liquid compared to the flash point of the pulverized liquid in the pulverizing compartment; as well as The recovered pulverizing liquid is supplied to the pulverizing compartment to replace at least a portion of the pulverizing liquid.

2. The process according to claim 1, further comprising: include: After pulverization and quenching, the pulverized battery residue is separated, and the black matter is also separated from the liquid.

3. The process according to claim 1, further comprising: include: The entrained low flash point solution is separated from the pulverized battery residue by drying and / or sinking and floating operations to increase the concentration of the high flash point solvent and reduce the flammability of the pulverized battery residue.

4. A process for recycling lithium batteries, The following steps are involved: pulverizing and quenching the lithium battery with a pulverizing liquid in a pulverizing compartment to safely discharge the battery and produce pulverized battery residue, black matter, and a liquid including an organic compound and a lithium compound; separating at least a portion of the liquid from the pulverized battery residue to obtain a separated liquid, the separated liquid comprising a low flash point solvent and a high flash point solvent; producing a recovered pulverized liquid from the separated liquid by removing at least a portion of the low flash point solvent, and / or increasing the concentration of the high flash point solvent in the recovered pulverized liquid to increase the flash point of the recovered pulverized liquid compared to the flash point of the pulverized liquid in the pulverizing compartment; supplying the recovered pulverizing liquid to the pulverizing compartment to replace at least a portion of the pulverizing liquid; separating entrained low-flash point liquid from the pulverized battery residue; separating the crushed battery residue and also separating the black matter from the liquid; mixing the black material with an acid to produce a slurry, and percolating the slurry to produce a leachate including soluble metal ions and non-percolatable material; filtering the leachate to remove the non-filterable material from the leachate; optionally supplying the leachate to a sulfide precipitation tank to remove ionic copper impurities from the leachate; removing iron and aluminum from said leachate; mixing the leachate with a first organic extraction solvent to produce an aqueous raffinate containing cobalt, nickel and lithium and an organic phase containing manganese; combining the raffinate with a second organic extraction solvent to produce a second aqueous raffinate containing nickel and lithium and an organic phase containing cobalt; increasing the pH of the second aqueous raffinate phase to a pH between 9.5 and 12 to precipitate the nickel from the aqueous phase, leaving the lithium in aqueous solution; crystallizing sodium sulfate from the aqueous phase containing lithium to produce a clear solution containing lithium and sodium sulfate crystals; as well as Lithium is recovered from the supernatant.

5. The process according to claim 4, in, The separation of the entrained low-flash point liquid from the pulverized battery residue is performed by drying and / or sink-float operation, and preferably sink-float operation.

6. The process according to claim 3 or 5, further comprising: include: A high flash point solvent is added in the sink-float operation to obtain pulverized battery residues with reduced flammability and to improve the recovery efficiency of black matter.

7. The process according to any one of claims 1 to 6, in, The high flash point solvent is selected from water phase, glycol or cyclic carbonate.

8. The process according to claim 7, in, The high flash point solvent is selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), propylene glycol (PG), ethylene glycol (EG), vinylene carbonate (VC), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), water and combinations thereof.

9. The process according to any one of claims 1 to 8, in, The step of increasing the concentration of the high flash point solvent comprises: increasing the relative amounts of the high flash point solvent and the low flash point solvent in the recovered pulverized liquid.

10. The process according to any one of claims 1 to 9, in, The step of increasing the concentration of the high flash point solvent comprises: adding a certain amount of the high flash point solvent to the recovered pulverized liquid.

11. The process according to any one of claims 1 to 10, further comprising: include: A portion of the pulverized liquid in the pulverizing compartment is removed, and a portion of the pulverized liquid is used in the step of producing the recovered pulverized liquid.

12. The process according to any one of claims 1 to 11, further comprising: include: removing a second portion of the pulverizing liquid in the pulverizing compartment; Producing a second recovered pulverized liquid from the second portion of the pulverized liquid by removing at least a portion of the low flash point solvent, and / or increasing the concentration of a second high flash point solvent in the second recovered pulverized liquid to increase the flash point of the second recovered pulverized liquid; and supplying the second recovered pulverized liquid to the pulverizing compartment.

13. The process according to any one of claims 1 to 12, in, The flash point of the recovered crushed liquid is greater than 38°C.

14. The process according to any one of claims 1 to 13, in, The steps of pulverizing and quenching are carried out at a temperature of less than 40°C.

15. The process according to any one of claims 1 to 14, in, Steps for removing the low flash point liquid include decantation, distillation, activated carbon extraction, filtration and / or liquid-liquid extraction.

16. The process according to claim 15, in, The step of removing the low flash point solvent is a decantation step, which includes adding Na 2 SO 4 , K 2 SO 4 , Li 2 SO 4 , NaCl, potassium sodium tartrate, sodium citrate, Na 2 FPO 3 、NaH 2 PO 4 , K 2 HPO 4 、Na 2 S 2 O 3 and (NH 4 ) 2 SO 4 One or more of .

17. The process according to claim 16, in, The salt is sodium sulfate.

18. The process according to any one of claims 1 to 17, in, Low flash point liquids include straight chain carbonate compounds.

19. The process according to claim 18, in, The separated high flash point solvent is recovered into the recovered crushed liquid.

20. The process according to any one of claims 1 to 19, in, The pulverized liquid includes a sufficient amount of water phase to neutralize the metallic Li into LiOH.

21. The process according to claim 20, in, The level of hydrogen in the exhaust gas from the pulverizing compartment is used to control the relative supply of the pulverizing liquid to the battery containing lithium metal.

22. The process according to claim 20 or 21, in, The residual hydrogen generated by the neutralization of Li to LiOH is reused or separated.

23. The process according to any one of claims 1 to 22, in, The recovered pulverized liquid is cooled to control the temperature of the battery during pulverization.

24. The process according to any one of claims 1 to 23, in, At least 50% of the F in the crushed liquid is in the form of PF 6 exists in the form of.

25. The process according to any one of claims 1 to 24, in, A selective diafiltration step is preceded by a diafiltration step followed by a magnetic separation step to recover the iron phosphate product alone and produce a lithium-rich stream.

26. A black substance obtained by the process according to any one of claims 1 to 25.

27. A black substance, include: Mn, Ni, Co, Li, LiPF 6 , non-leaching fluorine compounds, graphite, oxides and unavoidable impurities.

28. The black substance according to claim 27, further comprising moisture, wherein the moisture includes a linear organic solvent and a cyclic organic solvent and water.

29. The black substance according to claim 28, in, LiPF 6 Present in the moisture.

30. The black substance according to any one of claims 27 to 29, in, The non-leachable fluorine compound is polyvinylidene fluoride (PVDF).

31. The black substance according to any one of claims 27 to 30, in, The black substance does not contain metallic Li.

32. The black substance of any one of claims 27 to 31 further comprising plastic.

33. The black substance according to any one of claims 27 to 32, in, Moisture also includes glycols and alcohols.

34. The black substance according to any one of claims 27 to 33, in, The black substance has a pH of 5 or more.

35. A black mass according to any one of claims 27 to 34, comprising particles having an average particle size greater than 50 microns.

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