A method for selective leaching of lithium from lithium-ion battery waste

Abstract

The present disclosure provides a method for selective leaching of lithium from lithium-ion battery waste, the method comprising providing water and / or an aqueous solution (10), providing solid lithium-ion battery waste material (12), adding the solid lithium-ion battery waste material to the water and / or to the aqueous solution to obtain a mixture (!4), and providing the mixture in a reactor, providing CO2 to the reactor, maintaining the pressure of the reactor containing CO2 at 50 bar or less, maintaining the temperature of the mixture in the range of 120-250°C, reacting for a time required to leach the lithium (16), and separating liquid comprising leached lithium (18) and / or delithiated solid material (20).

Description

[0001] A method for selective leaching of lithium from lithium-ion battery waste

[0002] Field of the application

[0003] The present application relates to a method for selective leaching of lithium from lithium-ion battery waste.

[0004] Background

[0005] Lithium is an essential element in lithium-ion batteries. In common hydrometallurgical lithium-ion battery (LiB) recycling process, it ends up in metal solution during acidic leaching. Lithium has not been element of importance in commercial transition metal processes, for example in cobalt refining, or lithium is separated using pyrometallurgical pretreatment, but ends up in slag.

[0006] In prior art methods LiB waste is pretreated in pyrometallurgical (carbonating) or supercritical CO2 conditions and after that LiHCOs solution is formed reacting Li2COs (formed during the pretreatment) in ambient temperature or lower in CO2 pressure. However all the prior art methods are not suitable for industrial scale processes, and they may be complex and inefficient, and use very high temperatures. For example supercritical conditions are challenging to maintain industrially, and the small liquid volumes and need for specific methods and equipment, for example concentrating devices such as electrodialysis devices, make these methods unsuitable for several purposes.

[0007] There is a need to find simple and efficient methods for separating and recovering lithium from waste materials, such as from battery waste materials. Especially there is a need to find industrially applicable methods, which could broadly benefit different productions chains.

[0008] Summary

[0009] The present invention enables overcoming drawbacks of prior art. It was found out how to selectively leach lithium from waste material with a good yield. It was possible to obtain concentrated product in one step process, which is desired in industrial processes. The present methods relate to battery recycling, and enables separation of lithium from lithium ion battery waste with a reagent that improves quality of the black mass. The improved quality of the black mass improves Me:Li ratio of the pregnant leach solution. This also allows selective leaching of the lithium before further processing steps. The present method enables selective leaching and also providing delithiated raw material for further processes and industries, which desire to leach other metals from the raw material in the absence of lithium. As lithium is separated before leaching of transition metals, the present method facilitates treating, separating and recovering the transition metals. For example base metal industry extracts nickel and cobalt from the black mass and may not be interested on recovering lithium from their waste waters.

[0010] In the present methods, lithium-ion battery waste is pretreated in hydrothermal condition, which has lower temperature than pyrometallurgical pre-treatment and lower pressure and higher solid to liquid ratio than supercritical CO2.

[0011] The present methods preferably utilize CO2 as only reactant in leaching. CO2 may be provided as the only additional reactant to the reactor.

[0012] The present disclosure provides a method for selective leaching of lithium from lithium-ion battery waste, the method comprising -providing water and / or an aqueous solution, -providing solid lithium-ion battery waste material,

[0013] -adding solid lithium-ion battery waste material to the water and / or to the aqueous solution to obtain a mixture and providing the mixture in a reactor,

[0014] -providing CO2 to the reactor,

[0015] -maintaining the pressure of the reactor containing CO2 at 50 bar or less, -maintaining the temperature of the mixture in the range of 120-250°C, -reacting for a time required to leach the lithium, such as for 30 minutes or more, and

[0016] -separating liquid comprising leached lithium and / or delithiated solid material.

[0017] The main embodiments are characterized in the independent claims. Various embodiments are disclosed in the dependent claims. The embodiments and examples recited in the claims and the specification are mutually freely combinable unless otherwise explicitly stated. The present method enables providing raw materials for different fields of industry and / or different operators, which raw materials lack undesired compounds present in the original waste raw material. This facilitates the recycling of materials and metals, and lowers the need for different operators to carry out further purification steps and the like actions. It may be possible to directly use the obtained product in industrial processes, such as the leached lithium may be utilized as lithiation chemical.

[0018] The present method avoids using very high temperatures, which saves energy and makes the process more simply and safe. It is possible to implement the present method with existing and / or simple equipment.

[0019] Therefore the present method enables efficiently utilizing waste material and obtaining useful products with simple and more environmentally friendly processes utilizing less energy, chemicals and time compared to prior art processes. This applies also to different processes carried out subsequently by using the materials obtained from the present process, thus providing effects in production chains of a variety of industries and operators.

[0020] Brief description of the figures

[0021] Figure 1 shows yield of lithium as a function of temperature. 0.5 M nickel sulfate solution was used as the reagent.

[0022] Figure 2 shows yield of lithium as a function of metal sulfate concentration.

[0023] Figure 3 shows yield of lithium as a function of CO2 pressure. 0.5 M nickel sulfate solution was used as the reagent.

[0024] Figure 4 shows yield of lithium as a function of carbonation temperature in CO2 leaching without metal sulfate. Reaction temperature was less than 20°C.

[0025] Figure 5 shows a flowchart of the present method.

[0026] Detailed description

[0027] In this specification, percentage values, unless specifically indicated otherwise, are based on weight (w / w, by weight, or wt%). If any numerical ranges are provided, the ranges include also the upper and lower values. In specific examples the embodiments specified with the open term “comprise” may be further limited with a closed term “consisting of’.

[0028] The present disclosure provides a method for leaching, especially selective leaching, of lithium from lithium-ion battery waste. The method is carried out in a suitable rector or reaction vessel. The reactor may be a continuous reactor or a batch reactor. A continuous reactor may be maintained as pressurized and / or at a constant temperature, such as at a temperature range. The present process and devices used for implementing it are preferably industrial scale processes and devices, which have different requirements and running conditions compared to laboratory scale processes and equipment.

[0029] The method comprises providing water and / or an aqueous solution 10. The water may be any suitable water, such as tap water, especially in cases it fulfils the requirement of impurities. The water may be purified water, such as distilled water. The water may be provided initially, and one or more substances and / or agents may be added to the water, preferably in mixing. An aqueous solution may be obtained, which may also be a dispersion in case not all substances are solubilized.

[0030] The aqueous solution may be wastewater or reaction solution. The aqueous solution may comprise one or more metal sulfates MeSO4. The NCM ratios provided by the used battery waste material can be adjusted by providing a suitable MeSO4 solution with desired metal(s). The presence of suitable metal sulfates was found to enhance the leaching efficiency, as demonstrated by examples 3 and 5, and when comparing the results shown in Figures 1 and 4. The metal sulfate may comprise nickel sulfate, cobalt sulfate and / or manganese sulfate. In one example the aqueous solution comprises nickel sulfate, which was found advantageous for the efficiency of the lithium leaching. In general nickel rich materials were advantageous, and the amount of such materials are expected to be recycled in the future. The aqueous solution may also comprise cobalt sulfate and / or manganese sulfate. The aqueous solution may be NCM sulfate solution, for example with a desired Ni:Co:Mn ratio. The content of metal sulfates in the solution has an impact to the lithium leaching efficiency, as can be seen from Figure 2. The aqueous solution may comprise 0.1-3.0 M, preferably 0.1-1 .0 M, 0.2-1 .0 M, or 0.3-1 .0 M, of the one or more metal sulfates MeSO4, excluding I 2SO4 or I 2SO4 content. In one example the aqueous solution may comprise for 0.3-0.7 M of the one or more metal sulfates MeSO4, excluding U2SO4 or U2SO4 content, which concentration was found optimal, and resulted in a lower amount of impurities.

[0031] The aqueous solution 10 may be a leach solution of lithium-ion battery waste material, the leach solution comprising sulfates of lithium, cobalt, nickel and / or manganese. The leached lithium-ion battery waste material is not the solid lithium- ion battery waste material provided in the method, but has been treated previously and preferably in a separate process.

[0032] The aqueous solution 10 comprising one or more metal sulfates MeSO4 may be obtained by

[0033] -providing solid lithium-ion battery waste material, and

[0034] -leaching with sulfuric acid for form one or more metal sulfates. This step may be a part of the method, or the leach solution already exists or is obtained from another process.

[0035] The present method may comprise carrying out the reaction:

[0036] MeSO4 + 2LiMeO2 + COs2' Li2SO4 + 2Lii-xMeO2 + MeCOs, wherein X=0-1 , and / or the reaction:

[0037] MeSO4 + 2LiMeO2 Li2SO4 + 2Lii-xMeO2 + Me(OH)2, wherein X=0-1 .

[0038] The reactions may be facilitated by controlling the stoichiometry of the reagents and / or reaction conditions.

[0039] The method may comprise providing solid lithium-ion battery waste material. This material is not the same material used for obtaining the aqueous solution comprising one or more metal sulfates MeSO4.

[0040] The method comprises adding solid lithium-ion battery waste material 12 to the water and / or to the aqueous solution to obtain a mixture 14 and providing the mixture 14 in a reactor. If the reactor is closed and / or sealed, such as a continuous reactor, the solid lithium-ion battery waste material may be added to a water or aqueous solution in the reactor. The mixture in the reactor may be called a reaction mixture, and the temperature and / or pressure thereof may be controlled. The solid lithium-ion battery waste material 12 may comprise cathode material, such as lithium-ion battery black mass, which is obtained from lithium-ion batteries (LiB). The batteries are recycled, wherein they are dismantled, and cathode and anode materials are separated and disintegrated. The black mass may be provided as disintegrated material, such as ground particles, granules or the like. The black mass includes at least the cathode material, and it may also include the anode material, and / or electrolyte materials including organic compounds. The cathode material may comprise nickel, cobalt and manganese (NCM), and lithium in an amount for example in the range of 1-35% by weight. The cathode material may also comprise smaller amounts of for example tin, zirconium, zinc, copper, iron, fluoride, phosphorus and aluminum. Manganese is an important element in the cathode materials of lithium-ion batteries. It stabilizes LiNiC>2 structure, allows cobalt to improve conductivity of the cathode material and improves thermal stability of the material.

[0041] However undesired compounds may be removed from the initial black mass to obtain processed black mass suitable for the present purposes, such as material comprising mainly or substantially cathode material. For example the organic compounds are usually not desired as they may interfere or prevent the separation of metals in leaching. The black mass may be washed in one or more washing steps with water and / or with organic solvent(s). For example the organic compounds may be washed with organic solvent. Also one or more heating steps may be used to pyrolyze or evaporate undesired material, for example in combination with the washing step(s) or as an alternative method for removing undesired compounds. The anode material may include or be formed substantially of graphite or silicon.

[0042] A processed or pretreated black mass, which is purified of one or more substances and / or otherwise processed, may be obtained from such process steps, and can be used in leaching. The black mass discussed herein refers to such processed or pretreated black mass, unless otherwise mentioned. The black mass may be provided as powder. The solid lithium-ion battery waste material to be used as the raw material for the present method is preferably not delithiated.

[0043] The present method is especially suitable for cathode material, or material derived therefrom, having a high percentage of nickel in the transition metals of the cathode. The solid lithium-ion battery waste material may comprise Ni-rich cathode material, such as black mass comprising cathode material, wherein 50 mol-% or more of transition metals of the cathode material comprise nickel, such as 60 mol- % or more.

[0044] The solid lithium-ion battery waste material 12 may be provided to the reaction in a controlled amount to obtain a desired concentration in the reaction mixture 14. The concentration of the solid lithium-ion battery waste material in the (reaction) mixture may be in the range of 50-300 g / l, such as in the range of 100-250 g / l, for example 150-250 g / l.

[0045] The method may comprise providing CO2 as only reactant and / or as only added reactant or substance to the reactor and / or to the mixture 14. The aqueous solution and / or the solid lithium-ion battery waste material are not considered as reactants or added reactants or substances in this respect. Providing CO2 may be carried out continuously. The CO2 may be pressurized and / or providing the CO2 may result in pressurizing and / or increasing the pressure in the reactor. The present method does not include supercritical CO2. The method may comprise purging the reactor atmosphere with CO2, for example before providing CO2 to the reactor.

[0046] In the present method it is not necessary or desired to use very high pressure. As seen from Figure 3, efficient leaching of lithium could be obtained already at pressure below 30 bar. The method may comprise maintaining the pressure of the reactor containing CO2 at 50 bar or less, such as at 40 bar or less, even at 35 bar or less. The pressure may however be or be maintained at 10 bar or more, such as 15 bar or more, 20 bar or more or 25 bar or more. In examples the pressure is maintained in the range of 10-50 bar, such as in the range of 25-40 bar. The pressure may be, or be maintained, at said range during the reacting. The pressure in the reactor may increase due to increase of temperature in the reactor and / or reaction mixture. The pressure may be also increased by providing the CO2 as pressurized. It is possible to control the pressure and / or temperature in the reactor and / or in the reaction mixture by providing one or more pressure and / or temperature sensors, which may be connected to a controlling means, wherein the controlling means may be configured to carry out one or more controlling actions, such as releasing pressure by one or more valves and / or by heating and / or cooling, to adjust the pressure and / or temperature in the reactor and / or in the reaction mixture as feedback to the information obtained from the sensors. The reaction 16 is carried out at elevated temperature. However with the present method temperatures higher than 250°C are not needed and are preferably not used. The temperature of the solution has an impact to the lithium leaching efficiency, as can be seen from Figure 1. Efficient leaching could be obtained already at temperatures below 200°C. However temperature of at least 150°C was required to obtain a degree of lithium leaching of about 80%. As can be seen in Figure 4, using the same temperatures below 200°C without metal sulfates it was not possible to obtain the same leaching efficiency.

[0047] The method comprises maintaining, such as controlling, increasing, elevating, providing and / or adjusting, the temperature of the mixture to or in the range of 120-250°C. The temperature may be, or be maintained, at said range during the reacting. To ensure proper reactions, the temperature is preferably in the range of 150-250°C. The reaction may be carried out at a temperature in the range of 150— 210°C, such as 150-200°C, in which case very high temperatures can be avoided, thus making the process safer and saving costs and time.

[0048] The temperature is preferably controlled, such as the temperature may be elevated or increased to a desired range, and / or it may be maintained in the desired range by controlling one or more temperature controlling means in the reactor, such as one or more heating means, which may comprise one or more heating elements, in the reactor, such as in the reaction space, which contains the reaction mixture, or outside the reactor or reaction vessel, wherein one or more heating means may be arranged to control the temperature of the reactor or reaction mixture in the reactor. For example one or more heating means may be arranged in a sheath around the reactor or reaction vessel. The temperature may be maintained at said range at least for the reaction time.

[0049] The method comprises reacting for a time required to leach the lithium 16, preferably to a desired degree of leaching. A leached mixture is obtained. More particularly, the reactants are allowed to react 16 for a time period allowing obtaining a desired reaction degree, which may be a desired degree of lithium leaching. For example it may be desired to leach as much as possible of the lithium, or the reaction conditions may allow leaching at certain degree. For example the degree of lithium leaching may be 75% or more, 80% or more, 85% or more, 88% or more, 90% or more or 95% or more. The method may comprise reacting for time of 30 minutes or more, 60 minutes or more, such as for 30-240 minutes, for example 60-240 minutes. Optionally, after reacting, such as leaching, the method may comprise lowering the temperature of the mixture, or the leached mixture, to 90°C or less, to 60°C or less, or 40°C or less, such as to 25-90°C, to 25-60°C or to 25-40°C. This process step may be necessary in batch processes and reactors, wherein it may be desired to also lower the pressure to enable safe opening of the reactor. In continuous processes and reactors, especially in industrial scale processes and reactors, it is possible to remove the carbon dioxide pressure and / or filter the solution without lowering the temperature.

[0050] The method may comprise releasing pressure from the reactor and / or from the mixture, especially if the method is carried as a batch process and / or in a batch reactor. In continuous process increased pressure can be maintained in the reactor, preferably at a desired range, such as at 50 bar or less. In both cases the pressure may be controlled by releasing pressure, for example via one or more valves, if necessary. The mixture may be conveyed out from the reactor and the pressure may be also lowered in a separate unit.

[0051] The method comprises obtaining liquid comprising leached lithium 18 and / or delithiated solid material 20 and separating the liquid comprising leached lithium 18 and / or the delithiated solid material 20, such as from the leached mixture and / or from the reactor.

[0052] The present method may comprise, for example as shown in Figure 5, -providing water and / or an aqueous solution 10, -providing solid lithium-ion battery waste material 12, -adding or combining the solid lithium-ion battery waste material to or with the water and / or to or with the aqueous solution to obtain a mixture 14, and providing the mixture in a reactor,

[0053] -adding and / or providing CO2 to the reactor and / or to the mixture, preferably adding and / or providing CO2 as only reactant to the reactor and / or to the mixture, more adding and / or preferably providing CO2 as only added reactant to the reactor and / or to the mixture,

[0054] -maintaining the temperature of the mixture in the range of 120-250°C,

[0055] -reacting for a time required to leach the lithium 16, such as reacting for 30 minutes or more, and

[0056] -separating liquid comprising leached lithium 18 and / or delithiated solid material 20, for example from the reactor. The method comprises separating liquid comprising leached lithium from the reactor and / or from solids. This may involve filtering and / or other necessary methods or actions. Solids may be also separated from the reactor, or they may be further treated, such as washed. The solids, which have undergone delithiation and can be considered delithiated and / or Li-deficient solid material, may be provided for further leaching, such as in processes preferring solid raw material having low lithium content. “Delithiated” or “Li-deficient” as used herein refer to material wherein the lithium content has been substantially reduced compared to the original material, which has not treated with the present method. The substantially reduced lithium content may be 25% of the original lithium content or less, such as 20% or less, or even 15% or less, 12% or less, 10% or less, or 5% or less.

[0057] The present method may be a delithiation leaching, or a first leaching. The production chain may comprise one or more further leachings and / or further processing steps, which may be separate, i.e. which may be carried out at as a different / separate process, at a different location and / or by a different operator. For example one or more of nickel, cobalt and manganese may be leached and / or recovered from the delithiated material, such as solids. The present delithiation leaching method enhances these processes as there is no or only small amount of lithium present in the delithiated material, which could interfere the further processes. This enables selecting further processing methods, which would not be suitable if the material would have the original concentration of lithium. For example reducing agent free leaching can be carried out. For example it is possible to obtain more concentrated nickel solution and / or enhanced yield of nickel in a further leaching carried out at optimal conditions, as lithium is not present in substantial amounts. Obtaining concentrated metal solutions with good yield is especially advantageous in industrial processes.

[0058] The present method may be a pretreating method, which is to be carried out before a further treatment, such as further leaching. The present method may be a selective delithiation leaching of lithium-ion battery waste before (separate) leaching of one or more of nickel, cobalt and manganese. The present method may be a method for providing delithiated lithium-ion battery waste for leaching of one or more of nickel, cobalt and manganese. The method may comprise separating delithiated solid material from the liquid comprising leached lithium from the reactor, and providing the delithiated solid material for further processing, such as for leaching of one or more of nickel, cobalt and manganese.

[0059] The leached lithium may be recovered from the separated liquid. The recovered lithium may be provided for further processing, such as further purification, and / or for further use, for example after the further processing. Lithium can be separated and recovered by reacting lithium into its carbonate or phosphate, or converted into lithium hydroxide, which reaction products can be separated and collected. Lithium can be also recovered by solvent extraction, after which a further conversion or crystallization can be carried out. The recovery and further treatment and / or use of the lithium may be carried out by another operator.

[0060] During maintaining the temperature of the mixture in the range of 120-250°C lithium is converted into Li2COs. The method may further comprise lowering the temperature of the remaining solid material, i.e. the delithiated solid material, such as by treating the remaining solid material with cooled water, preferably under pressure and in the presence of CO2, to convert the Li2COs into LiHCOs. The method may comprise first separating the solid material from the mixture having the temperature in the range of 120-250°C, and subsequently leaching with a separate aqueous solution. The method may comprise lowering the temperature of the mixture to 30°C or less to convert the Li2COs into LiHCOs. The lithium carbonates may be utilized as such in certain processes, for example as lithiation chemicals, which enable directly producing useful reagents with the present method.

[0061] The method may subsequently comprise

[0062] -providing CO2 again as only reactant to the reactor, such as after lowering the temperature, wherein the temperature may increase or may be increased, -pressurizing the reactor containing CO2 to a pressure of 10 bar or less, such as to a pressure in the range of 5-10 bar, which may be caused by increased temperature and / or by pressurized CO2,

[0063] -lowering the temperature of the mixture to 20°C or less, such as to 10-20°C.

[0064] As in the steps involving increased temperature, also herein the reaction may be allowed to proceed until a desired reaction degree, i.e. conversion, is obtained. This may take 30 minutes or more, 60 minutes or more, 90 minutes or more, such as 30-240 minutes, 60-240 minutes or 90-240 minutes. The obtained solid material represents black mass with low lithium content, which can therefore be provided to operators interested in the other metals contained in the solids, such as operators of base metal industry.

[0065] Disclosed in use of any of the reactants for the method disclosed herein. For example disclosed is use of CO2 for the selective leaching of lithium from lithium- ion battery waste.

[0066] The present method may be carried out for example according to an example relating to use of CO2, preferably at a pressure in the range of 0 to 50 bar or less, as a reactant for hydrothermal conversion of lithium in LiB waste to Li2COs. In the subsequent step I 2CO3 is converted to LiHCOs by leaching in lowered temperature and with elevated CO2 pressure. Alternatively, I 2CO3 containing solid can be separated by filtration before subsequent step and LiHCOs conversion can be applied in a freshwater solution.

[0067] In one example battery waste is loaded to the reactor together with water. The reactor is pressurized with CO2. The reactor is heated to temperatures of 150°C or more, but 250°C or less. This was found advantageous for the disclosed reactions.

[0068] One example relates to use of MeSO4, such as Ni or a mixture of Ni, Co and Mn, and CO2 as a reactant for hydrothermal selective recovery of lithium. With correct dosage of reactants, more than 90% yield of lithium as Li2SO4 could be achieved together with low concentrations of NCM metals. Simultaneously, black mass NCM ratios could be altered by MeSO4 solution with wanted metal(s). Alternatively with only CO2 as a reactant, lithium could be extracted with good yield. After the pre-treatment upgraded black mass could be leached with good yield only using sulfuric acid as a leaching reagent.

[0069] In one example battery waste black mass is loaded to reactor together with NCM sulfate solution with wanted Ni:Co:Mn ratio. NCM sulfate solution may contain also initial concentration of Li2SO4 and a small amount of residual acid, which is usually the case with regular battery recycling solution. The reactor is pressurized with CO2. The reactor is heated to temperatures of 150°C or more, but 250°C or less. This was found advantageous for the disclosed reactions.

[0070] In one embodiment the method is a continuous method. The reactor may be a continuous reactor. A continuous reactor can handle the product as a flowing stream and may be able to cope with much higher reactant concentrations compared to batch reactors due to their superior heat transfer capacities. The small size of continuous reactors makes higher mixing rates possible. Continuous reactors may be designed for example as pipes with or without baffles or a series of interconnected stages.

[0071] The continuous method may comprise feeding solid lithium-ion battery waste material, CO2 and / or the aqueous solution comprising one or more metal sulfates MeSO4 continuously to the reactor. The reactor may be pressurized. The content of the reactor, such as the mixture, may be maintained at the temperature in the range of 120-250°C during feeding.

[0072] The reactor may be a batch reactor, and the method may be carried out as a batch process. In one example the reactor is an autoclave reactor.

[0073] The method may be carried out in a reactor and / or a device, or a setup or arrangement thereof, comprising one or more of the means disclosed herein, which means may be controllable, such as electronically controllable. The reactor and / or the device may be automated or semi-automated reactor and / or device, and it may be a part of a complex or a system. In one example the device, or a reactor setup or arrangement, comprises -one or more reactors or reaction vessels, -optionally one or more mixing means,

[0074] -one or more temperature controlling means, such as heating and / or cooling means, for example heating and optionally cooling means, and one or more temperature sensors arranged to measure the temperature of the reaction mixture in the reactor,

[0075] -one or more pressure sensors arranged to measure the pressure in the reactor, -wherein the mixing means, the temperature controlling means and pressure sensors are electrically controllable and preferably connected, such as operatively connected, to a controlling means, such as one or more control units, arranged to carry out the method steps disclosed herein, such as at least controlling the temperature and / or pressure in the reactor and / or controlling the mixing, and / or controlling the timing of the reaction and / or any of the actions.

[0076] The reactor may be any suitable reactor, which may comprise a container or a vessel, i.e. an enclosed volume in which a chemical reaction takes place. The reactor as used herein may refer to a reaction vessel. The reactor may include further parts associated with the container or the vessel, such as one or more inlets and outlets, such as equipped with valves, one or more sensors, one or more mixers, one or more openable and closable hatches or the like openings and other parts commonly used in the art. The reactor is preferably a pressure reactor. The reactor may comprise one or more valves, which may be operatively controlled by controlling means, which valves may control one or more outlets and / or inlets, for example for inputting and / or outputting liquid, gas and / or solids to or from the reactor.

[0077] The controlling means may be operatively connected to one or more means, devices, actuators, and the like disclosed herein, so that the controlling means can controllably operate the means, and / or connected to one or more sensors and other devices arranged to monitor the process, i.e. to obtain information from the process, such as from the reactor and / or reaction mixture.

[0078] The device may comprise heating means, such as one or more heaters, for example comprising one or more electrical heating elements, such as in the reactor arranged to heat the reaction mixture, and / or outside the reactor for example in a reactor envelope. The heating means may be operatively connected to the controlling means.

[0079] The device may comprise cooling means, such as one or more cooler, for example implemented with liquid flow in a rector envelope. The cooling means may be used for cooling i.e. lowering the temperature of the reactor mixture. The cooling means may be operatively connected to the controlling means.

[0080] The controlling means may be or comprise one or more electronic control units, which may be programmable, comprising one or more processors, memory, and software configured, when executed with a processor in the control unit, to carry out one or more operations to implement the method, for example to adjust the temperature of the reaction mixture by controlling the temperature controlling means, such as the heating and / or the cooling means, to control the mixing means to obtain a desired mixing of the reaction mixture, to monitor the temperature and / or other properties of the reaction mixture with one or more sensors in the reactor, and the like operations. The controlling means may be arranged, such as programmed, to monitor one or more properties from the device, the system, and / or the reactor, for example as a function of time, and as feedback to the monitored properties carry out one or more control actions in the device or the system to adjust the function of the device to carry out the present method. Properties such as temperature, pH, turbidity, absorbance, conductivity, flow rate, liquid level, control of addition of substances, mixing rate, and the like may be monitored with one or more sensors arranged to monitor said properties. For example temperature may be controlled to be at a predetermined range and / or to increase and / or decrease in a controlled manner to carry out the method.

[0081] Examples

[0082] The examples disclose processes, which were carried out as one-step reactions with MeSO4 solution, gaseous CO2 and Ni-rich Li-ion battery black mass in general according to the reaction:

[0083] MeSO4 + 2LiMeO2 + COs2' Li2SO4 + 2Lii-xMeO2 + MeCOs, wherein X=0-1 or with the reaction:

[0084] MeSO4 + 2LiMeO2 Li2SO4 + 2Lii-xMeO2 + Me(OH)2, wherein X=0-1 .

[0085] Example 1

[0086] 10 grams of NCM811 cathode material was weighted to an autoclave reactor together with 100 ml of H2O. The reactor was closed, atmosphere was first purged with CO2 and then pressurized up to 10 bar pressure with CO2. The reactor was heated to 150°C. After reaction time of 60 minutes, the reactor was cooled down to 25°C with circulating water through heat exchange loop. The reactor was pressurized again to 10 bar pressure with CO2 and cooled down to 15°C to form LiHCOs solution. Reaction resulted lithium yield of approximately 80%, with Li concentration of 5 g / l.

[0087] Example 2

[0088] 10 grams of cobalt rich LiB waste was weighted to an autoclave reactor together with 100 ml of H2O. The reactor was closed, atmosphere was first purged with CO2 and then pressurized to 10 bar pressure with CO2. The reactor was heated to 180°C. After reaction time of 60 minutes, the reactor was cooled down to 2°C with circulating water through heat exchange loop. The reactor was pressurized again to 10 bar pressure with CO2 and cooled down to 15°C to form LiHCOs solution. Reaction resulted lithium yield of approximately 40%, with Li concentration of 2.5 g / i. Example 3

[0089] Ni-rich battery waste leaching solution was diluted to 0.67 M (excluding I 2SO4 content) and is mixed with 20 grams of Ni-rich black mass and added to an autoclave reactor. The reactor was closed, atmosphere was first purged with CO2 and then pressurized to 26 bar pressure with CO2. The reactor was heated to 180°C. After reaction time of 135 minutes, the reactor was cooled to 90°C with circulating water through heat exchange loop. One of reactor valves was opened to release CO2 pressure. The reactor was further cooled to room temperature and opened. Solids and liquid were separated using vacuum filtration. Reaction resulted lithium yield of approximately 98.8%, with Li concentration of 8.7 g / l.

[0090] Example 4

[0091] 15.15 grams of Ni-rich black mass was added to an autoclave reactor with 100 ml of ion exchanged water. The reactor was closed, atmosphere was first purged with CO2 and then pressurized to 16 bar pressure with CO2. The reactor was heated to 200°C. As target temperature was reached, pressure of the reactor was 35.8 bars. Pressure peaked at 38.1 bars due to decomposition of the electrolyte components. After 3 hours reaction time, the reactor was cooled to 16.3°C. Pressure of the reactor was recorded as 11.8 bars. Pressure was released before opening the reactor. Solids and liquid were separated using vacuum filtration. Reaction resulted lithium yield of approximately 77.7%, with Li concentration of 3.8 g / l.

[0092] Example 5

[0093] Nickel sulphate solution was diluted to 0.67 M and mixed with 20 grams of Ni-rich black mass and added to an autoclave reactor. The reactor was closed, atmosphere was first purged with CO2 and then pressurized with CO2. The reactor was heated to 180°C. After reaction time of 90 minutes, the reactor was cooled to room temperature. One of reactor valves was opened to release CO2 pressure. The reactor was opened. Liquid and delithiated solids as leaching residue were separated by using vacuum filtration. Reaction resulted lithium yield of approximately 88% in the liquid, with Li concentration of 0.36% in the dried Li- deficient leaching residue.

[0094] The Li-deficient leaching residue was leached using 2.15 M H2SO4 solution and S / L 300 g / l at 90°C temperature for 2-hour period. Liquid and solids were separated by vacuum filtration. Reaction resulted solution with nickel concentration of 101 g / l. Yield of nickel was approximately 97%. Correspondingly, lithium concentration of the solution was 1.1 g / l and manganese only 26 mg / l. Manganese concentration in solid Li-deficient material was 1.2%, but in graphite residue it was concentrated to 3.7%.

Claims

Claims1. A method for selective leaching of lithium from lithium-ion battery waste, the method comprising-providing water and / or an aqueous solution (10),-providing solid lithium-ion battery waste material (12),-adding the solid lithium-ion battery waste material to the water and / or to the aqueous solution to obtain a mixture (14), and providing the mixture in a reactor, -providing CO2 to the reactor,-maintaining the pressure of the reactor containing CO2 at 50 bar or less, such as in the range of 10-50 bar, for example in the range of 25-40 bar,-maintaining the temperature of the mixture in the range of 120-250°C, such as in the range of 150-250°C,-reacting for a time required to leach the lithium (16), such as reacting for 30 minutes or more, such as reacting for 30-240 minutes,-optionally lowering the temperature of the mixture to 90°C or less, such as to 25- 90°C, and-separating liquid comprising leached lithium (18) and / or delithiated solid material (20).

2. The method of claim 1 , wherein the method comprises controlling the stoichiometry of the reagents and / or reaction conditions to carry out the reaction: MeSO4 + 2LiMeO2 + COs2' Li2SO4 + 2Lii-xMeO2 + MeCOs, wherein X=0-1 , and / or the reaction:MeSO4 + 2LiMeO2 Li2SO4 + 2Lii-xMeO2 + Me(OH)2, wherein X=0-1 .

3. The method of claim 1 or 2, wherein the aqueous solution (10) comprises one or more metal sulfates MeSO4.

4. The method of claim 3, wherein the aqueous solution comprises nickel sulfate.

5. The method of any of preceding claims, wherein the aqueous solution (10) is a leach solution of lithium-ion battery waste material, the leach solution comprising sulfates of lithium, cobalt, nickel and manganese.

6. The method of any of preceding claims, wherein the solid lithium-ion battery waste material (12) comprises cathode material, such as lithium-ion battery black mass.

7. The method of claim 6, wherein the solid lithium-ion battery waste material comprises Ni-rich black mass comprising cathode material, wherein 50 mol-% or more of transition metals of the cathode material comprise nickel.

8. The method of any of preceding claims, wherein the CO2 is provided to the reactor as the only added reactant.

9. The method of any of preceding claims, wherein the method further comprising lowering the temperature of the delithiated solid material, such as treating the delithiated solid material with cooled water, under pressure and in the presence of CO2, to convert I 2CO3 , which was formed when lithium was converted into I 2CO3 during maintaining the temperature of the mixture in the range of 120-250°C, into LiHCOs, preferably first separating the solid material from the mixture having the temperature in the range of 120-250°C, and subsequently leaching with a separate aqueous solution, preferably-lowering the temperature of the mixture to 30°C or less to convert the I 2CO3 into LiHCOs.

10. The method of claim 9, comprising-providing CO2 again as only reactant to the reactor after lowering the temperature -pressurizing the reactor containing CO2 to a pressure of 10 bar or less, such as to a pressure in the range of 5-10 bar,-lowering the temperature of the mixture to 20°C or less, such as to 10-20°C.

11. The method of any of claims 2-10, wherein the aqueous solution comprising one or more metal sulfates MeSO4 is obtained by-providing solid lithium-ion battery waste material, and-leaching with sulfuric acid for form one or more metal sulfates.

12. The method of any of preceding claims, wherein the concentration of the solid lithium-ion battery waste material in the mixture is in the range of 50-300 g / l, such as in the range of 100-250 g / l, for example 150-250 g / l.

13. The method of any of preceding claims, wherein the aqueous solution comprises 0.1-3.0 M, such as 0.2-1 .0 M, for example 0.3-0.7 M, of the one or more metal sulfates MeSO4, excluding I 2SO4.

14. The method of any of preceding claims, wherein the method is a continuous method and the reactor is a continuous reactor.

15. The method of claim 14, comprising feeding solid lithium-ion battery waste material, CO2 and / or the aqueous solution comprising one or more metal sulfates MeSO4 continuously to the reactor,16. The method of claim 15, wherein the reactor is a pressurized reactor and / or wherein the content of the reactor, such as the mixture, is maintained at the temperature in the range of 120-250°C during feeding.

17. The method of any of claims 1-13, wherein the method is carried out as a batch process and the reactor is a batch reactor, such as wherein the reactor is an autoclave reactor.

18. The method of any of preceding claims, wherein the method is a method for providing delithiated lithium-ion battery waste for leaching of one or more of nickel, cobalt and manganese.

19. The method of claim 18, wherein the method comprises separating delithiated solid material from the liquid comprising leached lithium from the reactor, and providing the delithiated solid material for leaching of one or more of nickel, cobalt and manganese.

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