Shredding method, apparatus, and system

Abstract

A method and apparatus for generating black mass by (a) receiving a feedstock 1 of one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or othe

Description

Field of the invention The present invention relates to a method of generating black mass through shredding of a suitable feedstock. The present invention is not particularly limited to any specific feedstock, so long as it comprises suitable materials to produce black mass, but may include a mixed source including one or more of EV batteries, power electronics batteries, consumer batteries, other electrochemical energy storage devices, such as capacitors or super capacitors, or waste from battery manufacture. The present invention has particular, but not exclusive, application in the production of sustainable materials for use of all types of lithium-containing batteries, such as, for example NMC, LFP, LMO, or LCO batteries, including high performance batteries designed for all types of electric vehicles including hybrid electric vehicles, consumer batteries, battery energy storage solutions, and gigafactory scrap. The present invention is not particularly limited to any specific cell chemistry and is suitable for use with a variety of cell chemistries. The present invention also relates to an apparatus configured to generate black mass from suitable feedstocks as well as a battery recycling system including such an apparatus. The present invention has particular, but not exclusive, application to the sustainable recovery of battery materials from electrochemical energy storage devices (as applicable to cell, module and pack), such as batteries, as well as from waste from battery manufacture, which includes components and raw materials used to manufacture electrochemical energy storage devices, such as batteries, but may be waste, scrap, or have some defect, meaning that it is unsuitable for use in an electrochemical energy storage device. Recovered materials may be recycled, re-engineered, and upcycled with a reduced carbon footprint and reduced cost compared with virgin materials. Background to the invention The need to recycle materials is becoming more important every year with a commitment to develop sustainable green processing technologies for recycling at scale. As the world seeks to decarbonise the global energy supply chain in order to meet net-zero goals, the materials that are used to create batteries or other electrochemical energy storage devices to power the decarbonisation of the world’s economy are in ever increasing demand as sourcing of critical minerals and metals become ever more problematic. The recent shift to renewable power and electric vehicles has created a high demand for battery materials. The raw materials that are used to create batteries, such as lithium, cobalt, nickel and manganese are in ever increasing demand and sourcing of their critical minerals and metals is becoming problematic Although it will continue to be necessary to obtain battery materials from primary sources, it is useful to also obtain battery materials by way of recycling or further processing secondary sources, such as used, defective, out of warranty, or end of life batteries or other electrochemical energy storage devices, especially EV batteries. Batteries have a limited lifespan and eventually need to be recycled or disposed. There are a number of existing ways in which batteries are recycled to recover useful materials. These existing ways generally include breaking down end-of-life batteries, extracting the black mass, and then recycling the black mass via hydrometallurgical or pyrometallurgical processes. For example, EP3517641 describes a method of recycling lithium batteries which includes digesting comminuted components of electrodes of lithium batteries with concentrated sulphuric acid at a temperature of at least 100°C in order to release hydrogen fluoride gas in a waste gas. This document describes how the digestion material comprises a maximum of 15% water, preferably less than 10% or preferably less than 5%, since if barely any or no water is present, fluoride in the form of HF is removed so that scarcely any or no fluoride compounds remain. In addition, this document describes deactivating raw comminuted material through heating. Whilst existing methods do allow for the recovery of valuable battery materials, such as manganese, cobalt, nickel, and lithium, from black mass, little consideration has been given on how to efficiently prepare the black mass. Since usage of electrochemical energy storage devices such as batteries and the recycling of such devices is intended to reduce dependence on natural resources and to aid the environment, it is desirable for all aspects of the lifecycle to be as efficient as possible in order to maximise the advantages and benefits of such devices. It is often the case that the sorting of batteries for end-of-life processing is difficult given the vast numbers of different types of batteries to process including a multitude of chemistries and formats and respective health scenarios. As a consequence, it is often overlooked that the quality and quantity of black mass produced is decreased due to the presence of batteries which contain earlier-generation cell chemistries, such as nickel cadmium batteries or lead acid batteries or others which include deleterious elements. This requires additional processing steps to be carried out on the resultant black mass in order to separate out the valuable materials, thereby adding additional process steps downstream, increasing production costs and decreasing competitiveness. It is therefore an object of the present invention to mitigate at least some of these problems as well as other known problems with existing methods. Summary of Invention According to a first aspect of the present disclosure, there is provided a method of generating black mass, the method including the steps of: a) receiving a feedstock from which black mass is to be recovered, the feedstock including one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or other electrochemical energy storage devices; b) separating the feedstock into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture; c) shredding the first stream in a wet shredder to form a wet shredded stream; d) shredding the second stream in a dry shredder to form a dry shredded stream; e) combining the wet shredded stream and the dry shredded stream to form a combined stream; f) processing the combined stream to form a black mass stream. As mentioned, the present disclosure is not limited to any particular feedstock other than that it has the capacity to form black mass when shredded or crushed. Black mass is a term of the art in battery recycling. Black mass contains the anode and cathode materials of batteries that have been shredded, crushed, or otherwise processed. Black mass includes carbon, which is the primary reason for its colour. The majority of other materials which are used to form a battery, such as plastics and casings, are removed from the shredded and / or crushed batteries to form black mass, which can subsequently be further processed to recover valuable materials therefrom, such as nickel wires, copper wires, foam, insulation, fire retardants, and packaging. It will be appreciated that the black mass may still include incidental amounts of plastics, casing pieces, or other pieces of battery, but it is inefficient to seek to remove every last piece of such materials. As such, the black mass may include incidental amounts of materials other than those derived from the anode / cathode of the electrochemical energy storage devices from which the black mass is derived. Battery scrap sourced through multiple sources of mixed feedstock may be processed at one or more Battery Recycling Stations (BRS) to produce black mass for downstream refining. This may include a mega-scale shredding facilities, with capacity to process over 60kt equivalent of batteries. The plant may process a mix of consumer batteries, EV batteries and gigafactory scrap through its multiphase shredders, delivering high-quality output material on an industrial scale. With the growing number of end-of-life batteries expected later this decade, scalable and efficient processing solutions will be critical to establish a sustainable and commercially viable recycling industry, capable of meeting the demands of OEMs and cell manufacturers. Manual dismantling and discharge will not be a viable option for at-scale recycling of hundreds of batteries per day. The feedstock may include any type of electrochemical energy storage device. Given the rapid increase in the number of electric vehicles, whether fully electric or hybrid, in the last few years and the predicted continued future growth, there will be a corresponding increase in the number of EV batteries which will need to be recycled in coming years. As such, a significant proportion of the feedstock will include EV batteries. In addition, power electronics batteries and consumer batteries will also continue to need to be recycled. In addition, although the manufacture of batteries and other electrochemical energy storage devices is highly optimised, there is still an inevitable large amount of scrap that is created, such as from gigafactories. This may include anything which has not met manufacturing parameters and therefore is not formed into a completed battery for whatever reason. As such, waste from battery manufacture may include anode materials and / or cathode materials as well as and work in progress materials from throughout the cell or battery pack assembly process. It is often the case that any defects are detected prior to completion of a cell or battery, so such materials may not include electrolytes and / or casings. Other electrochemical energy storage devices may include, for example, capacitors and super-capacitors. The method includes separating the feedstock into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture. The method may optionally include removing certain types of batteries that are unsuitable for processing, such as those containing heavy metals such as lead or cadmium, although these are preferably not included in the initial feedstock. There may also be early removal of black mass fallen off from electrodes before batteries are shredded. The first stream is shredded in a wet shredder to form a wet shredded stream. The second stream is shredded in a dry shredder to form a dry shredded stream. The wet shredded stream and the dry shredded stream are then combined to form a combined stream. The combined stream is then processed to form a black mass stream. By processed, this is understood to be the removal of materials other than black mass, such as any plastics, pieces of casings, and the like. It will be appreciated that the wet shredding step may be conducted on full size battery packs, for example battery packs from an electric vehicle, such as, for example, a Tesla ® or Audi ®. The size of the shredders can be appropriately sized to accommodate a wide range of battery formats. Therefore, the shredder may be capable of shredding such large format batteries. The shredder may be capable of shredding batteries whether the batteries are loose or not. The shredder may be capable of shredding batteries up the size of a laptop and beyond. Any suitable shredder type may be used, for example small to large, and including a dual, triple, or quad shaft shredders, to control the rate of size reduction in any single pass going from a small rate to a high rate respectively, so that such suitability can accommodate materials of different hardness. The wet shredder is advantageous in processing batteries since the batteries will include fluorine-containing compounds, such as separators and electrolytes. In addition, the batteries may be at least partially charged, which can be a fire hazard without proper mitigation in place, which is provided by utilising a wet shredder. The liquid used may be an aqueous brine. The liquid may be basic. As such, the liquid may be a basic aqueous brine. Although it is possible to use water, a basic aqueous brine has certain advantages. Firstly, in view of the presence of fluorine-containing compounds in the batteries, the brine may include chemical components, such as calcium and / or other alkaline earth elements which form insoluble fluoride compounds in substantially aqueous solutions, which can abate the fluorine by converting it into a form that can be separated from the black mass. For example, calcium fluoride is very insoluble and can therefore be readily separated from the liquid. When black mass is processed, it is usually leached in acidic conditions. If there is fluorine present, this can generate HF gas, which is very dangerous and requires abatement, which adds to downstream costs. In addition, since some of the batteries may retain some charge, wet shredding can mitigate the risk of fires. Furthermore, it is possible to alter the pH of the liquid to control the leaching of lithium since leaching of lithium is more prevalent in basic conditions, specifically for obtaining lithium from graphite or anode material. In this way, the liquid used in the wet shredding step may contain lithium and so may be processed to recover the lithium. A further advantage of the method according to the first aspect of the present disclosure is the increased efficiency of processing the combined stream to form a black mass stream. The wet shredded stream will contain an amount of water and a loading of solids. The addition of the dry shredded stream will increase the loading of solids. As such, the combined stream has a higher loading of solids than the wet shredded stream. It has been found that downstream processing of the combined stream into a black mass stream and a waste stream containing solids which are not black mass is more efficient when the solids loading is greater than that of the output of a wet shredder. By adding in a dry stream, it avoids the need to have a dewatering step and thereby simplifies the flowsheet since dewatering requires additional plant equipment and adds operational costs. In addition, the overall size of the plant required is smaller due to the lower footprint of a dry shredder as compared to a wet shredder and also the amount of water which needs to be handled and treated is reduced since wet shredders require a lower solids loading to operate than a downstream processing step requires. Furthermore, dry shredders require less electrical power to operate than wet shredders and so being able to process a portion of the feedstock using less power and which also leads to downstream efficiencies as compared to simply shredding everything in a single shredder provides beneficial green credentials to the recycling process. In addition, the waste from battery manufacture is usually easier to shred (having softer materials) than completed (sealed and formed) batteries or other electrochemical energy storage devices and is not a complete battery so there is less or no concern about the risk of fire or explosion. The method may include measuring one or more parameters of batteries or other electrochemical energy storage devices within the feedstock to screenthe likely cell chemistry of the batteries or other electrochemical energy storage devices. Since there is a whole range of cell chemistries, it may be useful to have at least an estimate of the cell chemistries of the feedstock being processed. Such knowledge can be used to avoid processing batteries having undesirable chemistries and which would contaminate the black mass product or to control the composition of the black mass obtained. Additionally or alternatively, this knowledge can allow the order of the batteries being fed into the process to be controlled such that there is a more consistent batch flow of type of cell chemistries through the process. For example, most EV batteries are NMC batteries which have a high content of valuable materials. Other cell chemistries, such as LFP, may also be processed but have a lower proportion of valuable materials. As such, by having some idea of the cell chemistries of the feedstock being processed, it is possible to select the types of cell chemistries being processed. It may be the case that it is desirable to process cells having the same or similar chemistries together or it may be the case that certain batteries can be temporarily stored to make sure that there is an even flow of cell chemistries through the process. Additionally or alternatively, the method may include screening batteries or other electrochemical energy storage devices which are suitable for re-use, or recycling (direct or indirect) and separating such batteries or other electrochemical energy storage devices. Measuring one or more parameters of batteries within the feedstock may include measuring the physical dimensions of the batteries of all types of battery formats, such as aspect ratios, measuring the weight of the batteries, measuring an elemental composition of the batteries, and / or comparing images of the batteries to a database of images. As such, the method may include taking an image of a battery or other electrochemical energy storage device, processing the image by a processor to perform feature recognition to identify one or more features, and comparing such features or combinations thereof to a database. As such, it is not necessarily required to compare entire images, but it is also possible to look for signature features or identifying features, which could include any shapes, colours, markings, relative locations of features, or combinations thereof, and these features could be compared to a database of such features in order to determine the type of battery. Shape can include different formats, such as cylindrical, prismatic, or pouch. Signature features may include special can ends seen in plain view, such as the tabless features of a Tesla®, and with particular welding. Other measurement methods may include using neutrons or x-rays to determine the composition of the batteries or other electrochemical energy storage devices. Another example is determining the material of the casing, or can, or can ends, of a battery, which is usually steel for NMC batteries and aluminium for LFP batteries. A Hall effect sensor or other magnetic sensor may be used to make such determination. Any other suitable method may be used. The physical dimensions may be measured by optical means, such as by way of one or more cameras configured to image the batteries and calculate the physical dimensions. The physical dimensions may be measured by acoustic means, that is using sound waves in a similar way to sonar to measure the time taken for sound waves to be reflected from a surface and, knowing the speed of sound and the time taken for a sound wave to be returned, the distance between the acoustic means and the battery can be calculated, meaning that the dimensions of the battery can be calculated. The batteries may alternatively or additionally be imaged and those images compared to a database of known batteries with associated known cell chemistry. The method may include determining a weight: volume ratio of the batteries to screen the likely cell chemistry of the batteries. Unfortunately, at present, there is no requirement for manufacturers to disclose the cell chemistries used in the cells forming a battery and it is therefore difficult to determine the cell chemistry without dismantling the battery and checking the cells. This is time-consuming, expensive, and also potentially dangerous to operators. It has been surprisingly found that the likely chemistry of cells within a battery can be determined by determining the weightvolume ratio of the batteries containing the cells. In this way, it is possible to readily and easily distinguish between different cell chemistries without the need to dismantle the batteries since the density of batteries, particularly EV batteries, has been found to be indicative of cell chemistry. The components required to weight and measure the dimensions of a battery are well-known, readily available, and affordable, so being able to screen the likely cell chemistry without the need to dismantle the batteries is very useful. Separating the feedstock into a first stream and a second stream may include diverting the feedstock onto separate conveyors. Having separate conveyors allows the different streams to be fed to the different shredders. In addition, the rate at which the separate streams are provided to the respective shredders can be controlled such that the composition and sizing of the subsequent combined stream can be controlled. The method may include separating the first stream into a first substream and a second substream. The first substream may include EV batteries and the second substream may include the remaining batteries or other electrochemical energy storage devices. The first and second substreams may be shredded in separate shredders. In this way there may be two wet shredders and one dry shredder. It will be appreciated that there may be one or more additional shredders. By dividing the streams, the wet shredders can be appropriately sized to receive the respective feedstocks. The method may include shredding the feedstock such that the shredded material has the same passing size. Passing size is the size of materials which are able to pass through a grid or sieve of given size. Passing size may be controlled by selection and control of the shredders. By having the same passing size, the resultant shredded material is more uniform in size and so downstream processing can be optimised. The method may include re-shredding any oversized materials. This may include passing any oversized materials back to the wet and / or dry shredder. The wet shredding step may include shredding the first stream at least partially submerged. The material which is being wet shredded may be shredded whilst totally submerged. The method may include at least partially dewatering the black mass stream from step f). The black mass stream from step f) will include water and it may be advantageous to remove at least some of this water. Such water may be recovered for further processing, which may include extracting lithium or other valuable material dissolved in the water or treating the water to remove or control the build up of organics. The water to be recycled back into the wet shredding step. In this way, the method is environmentally friendly as the water can be recycled and does not need to be discharged. Having less water in the black mass reduces weight which makes transportation easier. The method may include screening the wet shredded stream and / or the dry shredded stream, and passing oversized materials back into a shredding step. As mentioned, any oversized materials can be re-shredded so that they are reduced in size to the desired size. The method may include recovering black mass from different stages of the process. During the shredding process, black mass will be generated and may separate from the streams of shredded material at different stages of the process. Such black mass may separate from the streams of shredded material due to having an increased density as compared to the other black mass in the process. Black mass with a higher density may contain a greater proportion of valuable materials and may therefore have a higher value than black mass obtained at a later part of the process. In this way, a higher recovery rate of black mass is achievable throughout the processing steps, such that higher grade black mass can also be fast tracked at the outset. According to a second aspect of the present disclosure, there is provided an apparatus for generating black mass, the apparatus including: a) a separator configured to separate a feedstock including one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or other electrochemical energy storage devices, into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture; b) a wet shredder configured to receive and shred the first stream to form a wet shredded stream; c) a dry shredder configured to receive and shred the second stream to form a dry shredded stream; d) a combiner configured to combine the wet shredded stream and the dry shredded stream to form a combined stream; and e) a processing apparatus configured to separate black mass from the combined stream. As with the first aspect of the present disclosure, the apparatus provided for the separate dry and wet shredding of different streams of material and the subsequent combining of the output streams from the wet and dry shredders. The combined stream may then be processed to obtain a black mass stream. By combining the dry shredded stream with the wet shredded stream, the combined stream has a higher solids loading which makes downstream processing more efficient and which also reduces the size of downstream apparatus since less volume needs to be handled. The apparatus may include an identifier configured to screen the likely cell chemistry of the batteries in the feedstock. The identifier may be configured to measure one or more parameters of batteries within the feedstock include measuring the physical dimensions of the batteries, aspect ratios, measuring the weight of the batteries, measuring an elemental composition of the batteries, or comparing images of the batteries to a database of images. The identifier may be configured to screen a weight:volume ratio of the batteries to determine the likely cell chemistry of the batteries. As discussed, measuring the weight and volume of a battery of other electrochemical energy storage device is possible with a range of existing techniques and can be used to screen the likely cell chemistry within such a battery or electrochemical energy storage device. This is applicable to the cell, module, and / or pack. The separator may include a further separator splitter connected to two or more output conveyors. In this way, the flow of materials on the conveyor may be separated into two or more streams. In particular, the apparatus may be configured to divide the first stream into a first substream including EV batteries and a second substream including the remaining batteries. The apparatus may include separate shredders for the first substream and the second substream. In this way, the separate shredders can be appropriately sized and specified for the different material streams. This saves on both capital expenditure and operational expenditure. The shredders may be configured to provide shredded material having the same passing size. By same passing size, this is understood to be within 10%, within 8%, within 5%, or within 1% of a predetermined passing size. The wet shredder may be configured to shred the first steam as it is at least partially submerged. By at least partially submerging the first stream, the risk of explosion and fires is reduced. In addition, any gases released by the materials being shredded is abated. The processing apparatus may include at least one set of dewaterering apparatus configured to at least partially dewater the combined stream. Since the combined stream includes both the wet shredded stream and the dry shredded stream, it is useful to remove fluid from the combined stream. The fluid may be recycled back into the shredding system and / or may be treated to remove any dissolved valuable materials, such as lithium. The apparatus may include one or more screens configured to selectively separate shredded material depending on size. Additionally or alternatively, the apparatus may include a recycle path for passing oversized materials back into a shredder. As such, any oversized materials may be re-shredded until they achieve the desired passing size. Preferably, it is the wet shredded stream which is recycled back to the wet shredding step. It will be appreciated that oversized materials from the dry shredded stream may be recycled back to a dry shredding step or a wet shredding step, but materials from the wet shredded stream is recycled back to the wet shredding step. According to a third aspect of the present disclosure, there is provided a battery recycling system including the apparatus according to the second aspect of the present disclosure. The battery recycling system may further include a processing system for processing black mass. The processing system may be any suitable processing system, such as a hydrometallurgical recovery system, a pyrometallurgical recovery system, and / or a solvent-based recovery system. It will be appreciated that the method according to the first aspect of the present disclosure and / or the apparatus according to the second aspect of the present disclosure may include the hydrometallurgical processing method and / or apparatus as described below and as described in co-pending UK patent application no. GB2401211.4, the content of which is incorporated in its entirety by reference. In particular, it will be appreciated that the black mass provided by the present invention may be the input material to the hydrometallurgical processing invention described in GB2401211.4. As such, the method according to the present invention may include the initial sorting, shredding and processing steps to provide a black mass, following which the black mass may be processed according to the hydrometallurgical process as described in GB2401211.4. Similarly, the apparatus described in GB2401211.4 may be provided in combination with the apparatus described herein, such that the apparatus described herein provides the black mass which is processed in the hydrometallurgical apparatus described in GB2401211.4. As such, the hydrometallurgical processing may include a method of recovering material from a source material, namely the black mass, comprising one or more target metals, the method including the steps of: a) contacting the source material with water and acid to leach one or more target metals from the source material to form a pregnant leach solution; b) monitoring one or more of: i) foaming, ii) the rate of change of concentration of one or more target metals in the pregnant leach solution, iii) the rate of change of pH, and iv) the initial concentration of one or more target metals to determine when to cease addition of acid such that all target metals have been solubilized and the pH is between 0 and 2.3; c) adding a reducing agent, preferably a peroxide, whilst maintaining the temperature of the pregnant leach solution at 85°C or less and monitoring one or more of: i) foaming, ii) the rate of change of concentration of one or more target metals in the pregnant leach solution, iii) the rate of change of pH, and iv) the initial concentration of one or more target metals in the source material; and the pH is between 1 and 2.3 to determine when to cease addition of reducing agent; d) adding a base to the pregnant leach solution to increase the pH of the pregnant leach solution to around 5 to 5.3 and providing an oxidizing agent to precipitate any intermediary metals or metal compounds, such as copper, aluminium, and iron, from the pregnant leach solution to form a depleted leach solution; e) performing a copper cementation reaction to remove copper from the depleted leach solution if copper is present; and f) recovering one or more target metals from the depleted leach solution to provide a lithium leach solution. Source materials, namely the black mass referred to herein, preferably contain one or more of manganese, cobalt, nickel, and lithium, often contain other materials or metals such as aluminium, iron, copper, graphite, silicon, and possibly even cadmium. It is desirable to separate these different materials from one another so that the valuable materials may be re-used to form useful materials. Useful materials may include precursors to active electrode materials, cathode or anode active materials for use in batteries, cathode or anode active materials for use in batteries, as well as materials for any other use, such as, for example, speciality and technical material manufacture such as alloys, coatings, composites, alloys, performance additives agrichemical, construction materials, fertilizers, electrical components, and pharmaceutical derivatives. It is possible to leach metals into solution by contacting them with acid. Although a wide variety of acids could be used, for example hydrochloric acid, nitric acid, perchloric acid, hydrobromic acid, organic acids, aqua regia, or mixtures of any thereof, it is preferable to use sulphuric acid due to its availability, price, and suitability for use in a material recovery plant. Preferably, the sulphuric acid is not concentrated sulphuric acid at the point of process. In other words, concentrated sulphuric acid is not what is in contact with the material from which metals are being leached, but dilute acid is instead what is in contact with the material from which metals are being leached. For example the sulphuric acid may be 70% (mass fraction) or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, or 10% or less. In the present context, concentrated sulphuric acid is defined as being greater than 70% (mass fraction). Typical commercially available concentrated sulphuric acid is 96% (mass fraction). Where other acids are used, they will have different parameters for defining whether the acid is concentrated or not. For example, concentrated hydrochloric acid is typically around 20% (mass fraction) or greater. Concentrated typically is defined by the azeotropic minimum water concentration or maximum dissolved in water under reasonably safe manufacturing and transport conditions. The addition of concentrated sulphuric acid may lead to the production of hydrogen fluoride gas from fluorinated compounds in the source material (at rates that are difficult to control), is highly toxic, more volatile, more difficult to handle and more difficult to control in chemical reactions. The amount of acid at the beginning of the leaching step may be around 35%, 30%, 25%, 20%, 15%, 10% (all w / v%) of the acid. As the leaching progresses and consumes the acid, this will drop overtime. Staged addition of further acid will at least partially replace any acid which has been consumed in the reaction or otherwise lost. It will be appreciated that in step d), the metals may precipitate in metallic form, but not necessarily and may additionally or alternatively precipitate as a compound including the metal. In addition, in step d) some copper may precipitate from solution, although the majority of any copper is removed in a subsequent cementation reaction step. The hydrometallurgical process may include adding water to the source material, i.e. black mass, and then adding sulphuric acid to leach metals into solution. The addition of water assists in mitigating the amount of HF gas produced. Preferably there is more than 15% (w / v%) water present. The present disclosure describes an aqueous method of leaching and recovery of materials from a source material. This leaching process generates gases which cause foaming or bubbling, which is indicative of the reaction proceeding. In particular, the reactions generate hydrogen gas which causes bubbling or foaming. Although an anti-foaming agent could be added, it is preferable for one not to be added as this will increase costs, introduce potential contaminants that will ultimately have to be removed, and would also prevent one way of determining when the reaction is complete since no foam would be generated. In steps in which gas is generated which can cause foaming or bubbling (which foaming could be caused by dissolved polymers from the anode material), physical countermeasures may be employed. For example, the solution may be recirculated and sprayed on the top of the solution to control the foaming or bubbling. Additionally or alternatively, one or more physical foam breakers, such as a beater or a centrifugal flail, positioned above a liquid line may be used to beat and break any foam on contact. The amount of acid added, preferably sulphuric acid, is preferably greater than the stoichiometric amount required to leach all of the metals from the source material. For example, the amount of sulphuric acid added may be 1.01, 1.02, 1.02, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, or 1.15 times the stoichiometric amount. In this way, there is just more than enough acid to leach any valuable metals from the source material, thereby ensuring maximum recovery of the metals and minimal use of reagents. In addition, since it will be necessary to ultimately neutralise the acid, it is desirable to control the amount added in order to avoid unnecessary wastage of acid and neutralisation agent by adding too much acid above the stoichiometric amount. In solution, acid serves as the oxidant for any aluminium, copper, or iron in solution. In the presence of acid, peroxide is a reducing agent for manganese and cobalt oxides, which can then be neutralised by acid. For nickel oxide, the acid serves as a neutralisation agent. The combined acid demand, which is dependent on the chemistry and amount of any leachable species as well as the desired final pH, can be calculated or estimated based on the characteristics of the initial feedstock. By adding slightly more than the stoichiometric amount, it can be assured that all leachable species have been leached into solution. The processing may include monitoring the reaction by one or more of foaming, the rate of change of the concentration of one or more target metals in the pregnant leach solution, the rate of change of pH, and the initial concentration of one or more target metals to determine when to cease addition of acid such that all target metals have been solubilized and the pH of the solution is between 0 and 2.3. Since gases are produced when there is an ongoing reaction, monitoring of the foaming can be used to determine when acid addition can be stopped since hydrogen gas will no longer be formed once all of the metals have been leached into solution. Similarly, the method may include monitoring the concentration of one or more target metals, such as manganese, cobalt, nickel, lithium, aluminium, copper, or iron, in the pregnant leach solution since the concentration will increase as long as there is more of the target metal to be leached. Once there is a constant concentration of the metal, taking into account any additional liquid added which would dilute the concentration but not the overall mass of metal in solution, addition of the acid may be ceased. Similarly, since the reaction with any metals will destroy the acid, knowing the rate at which acid is being provided, it is possible to monitor the rate of the change in pH to determine when the acid is no longer being used up in leaching the metals into solution. Furthermore, it is possible to calculate, based on the initial concentration of one or more target metals, how much acid needs to be added and by monitoring the initial concentration of the one or more target metals in a batch, it is possible to ensure that the correct amount of acid is added to leach the metals from the material and to also provide a solution within the given pH range. The method requires that the pH of the pregnant leach solution is between 0 and 2.3 in order to ensure that solubilised metals in solution remain in solution. The processing may further include adding a reducing agent, such as a peroxide, preferably hydrogen peroxide or sodium peroxide. Additionally or alternatively, the reducing agent may be sulphur dioxide, or an organic acid, such as oxalic acid, or a mixture of any of the reducing agents mentioned to the pregnant leach solution. Perhaps unexpectedly, the peroxide acts as a reducing agent in this step. Similarly, the sulphur dioxide or organic acid are also selected to serve as reducing agents. The reducing agent is selected so as to be unreactive against the highly acidic environment whilst also limiting the amount of any new or additional metal content into solution. The processing may include keeping the temperature at 85°C or less in order to reduce the amount of acid gas, specifically hydrogen fluoride, being produced as this is a dangerous gas and needs to be scrubbed from any waste gas and to prevent spontaneous decomposition of peroxide. The processing may include keeping the temperature at 75°C or less, 65°C or less, 60°C or less, 55°C or less, 50°C or less, 45°C or less, or less than 50°C. In addition, hydrogen peroxide is susceptible to decomposition at increased temperatures, so using temperatures greater than 85°C would cause the hydrogen peroxide to decompose into oxygen and water without having sufficient time to react and would therefore simply be wasted due to decomposition rather than chemical reaction. The total amount of peroxide added may be calculated as the stoichiometric amount plus a calculated excess. The amount of peroxide, or indeed other reducing agent, added may be 1.01, 1.02, 1.02, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, or 1.15times the stoichiometric amount. It has been found that using a less than stoichiometric amount does not lead to any selectivity regarding target metals and instead causes a loss of efficiency. This step also includes monitoring one or more of foaming, the rate of change of the concentration of one or more target metals in the pregnant leach solution, the rate of change of pH, and the initial concentration of one or more target metals to determine when to cease addition of peroxide / reducing agent. Preferably, the reducing agent, preferably a peroxide, preferably hydrogen peroxide, is added to the solution until the rate of change of pH over time and / or the rate of change of the concentration of one or more target metals tends to a predetermined value, which is preferably zero which indicates that the reaction is complete. The pH must end up between 1 and 2.3 in order to ensure that the metals remains in solution. Acid may be added to control the pH as required. The acid and / or peroxide may be added steadily or in batches. The processing method may primarily be a batch process. The processing method may further include adding a base subsequent to the completion of the addition of the reducing agent, preferably hydrogen peroxide. The base may be selected from one or more of sodium hydroxide, calcium hydroxide, calcium carbonate, calcium oxide, magnesium carbonate, magnesium oxide, magnesium hydroxide, nickel hydroxide, cobalt hydroxide, manganese hydroxide, lithium hydroxide, mixed hydroxide precipitate, or a combination thereof. Although sodium hydroxide can be used, the base is preferably not sodium hydroxide since this results in the formation of sodium sulphate. Sodium sulphate as a by-product has a number of disadvantages. Firstly, sodium sulphate is in sufficient supply and is a low value by-product since it is generated in excessive quantities in parallel industries, such as a by-product in the manufacture of nylon and this supply is sufficient to meet the needs of sodium sulphate in the washing powder and pulping agent industries, and so the demand of sodium sulphate in the marketplace is already easily met. With ever increasing rates of recycling of battery materials, the supply of sodium sulphate is set to increase further. In addition, sodium sulphate accumulation in the system throughout is hard and expensive to remove. The solubility of sodium sulphate in water is unusually dynamic in that it increases by around ten times as the temperature of water increases from around 0°C up to around 32°C. As the solubility of sodium sulphate is heavily dependent on temperature, having sodium sulphate dissolved in a solution within a recycling process causes issues since the temperature either needs to be controlled and kept above ambient temperature to avoid the sodium sulphate crystallising out of solution at an undetermined step in the process, which can cause blockage of filters, pumps, or pipework in a plant or more generally contaminate and devalue products at different stages of the process, or the process needs to include an additional step towards the beginning of the process in which a large volume of solution needs to be cooled to knock out the dissolved sodium sulphate, filtered, and then reheated in order for subsequent reactions to take place at an acceptable rate. Both of these options incur high additional costs, which are not offset due to the low value of the sodium sulphate product. As such, the present process seeks to avoid these problems by minimising the production of sodium sulphate. Calcium hydroxide, calcium oxide, and calcium carbonate as well as magnesium hydroxide, magnesium oxide, and magnesium carbonate are suitable as a base for a number of reasons. In addition to being a base, calcium will react with any available fluoride to form calcium fluoride, which are extremely poorly soluble in water and therefore is removed from solution. Magnesium fluoride is also poorly soluble in water, meaning that it can be removed from solution readily. In this way, the method includes a fluorine mitigation or fluoride scrubbing step. This mitigates the risk of hydrogen fluoride gas being released and residual hydrofluoric acid remaining in solution, which is a large risk when battery materials are being recycled due to the presence of fluorinated compounds in batteries. In addition, calcium sulphate is only sparingly soluble in water, unlike sodium sulphate, and therefore is readily removed from solution, such as by filtering, and does not require such rigorous thermal control of the solution. Magnesium sulphate is also poorly soluble in water. Furthermore, calcium sulphate, also known as gypsum, is much more valuable than sodium sulphate. After removal of calcium sulphate from solution, the osmotic pressure of the solution is reduced and so the solution can be concentrated without the risk of precipitation. The processing method may include one or more filtration steps whenever a solid material needs to be removed. Any known filtration method may be employed and the present invention is not particularly limited by any specific filtration method. For example, graphite may be filtered from solution after the initial leaching step. The nickel hydroxide, cobalt hydroxide, and manganese hydroxide, possibly as a mixed metal hydroxide, may be produced at a later stage of the process and may therefore be recycled back into the process to adjust the pH of the pregnant leach solution to precipitate any intermediary metals or materials, such as copper, aluminium, or iron. As such, one or more of the lithium hydroxide, manganese hydroxide, cobalt hydroxide, and nickel hydroxide may be a recycle stream at least partially obtained from the depleted leach solution. An intermediary material or metal is a material or metal other than nickel, cobalt, manganese, and lithium which needs to be removed from solution at some stage of the process. This may include one or more transition group metals. The pH of the pregnant leach solution is adjusted to around 5 to around 5.3, which causes any solubilised iron and aluminium to precipitate out of solution. An oxidising agent, such as air, is provided to assist with precipitation of any aluminium or iron. The process may further include a copper cementation, otherwise known as copper scrubbing, step to remove copper from the depleted leach solution if copper is present. Where the source material includes any batteries or battery-related materials, such as battery manufacture scrap, it is likely that the solution will include copper. In a copper cementation process, a redox reaction between metallic iron and copper in solution results in copper metal precipitating out of solution. In particular, the exemplary reaction may be: Fe(s) + Cu2+ —► Cu(s) + Fe2+ Fe2+ + O2+H2O —► Fe(O)OH Indeed, any metal with a more negative standard electrode potential than copper may be used and the process is not limited to metallic iron. A copper cementation process usually includes an oxidiser, such as air (or such as peroxide, hydrogen peroxide), to oxidise iron, or other metal, in solution, which can precipitate out as iron (III) oxyhydroxide. The precipitated copper and iron, or other metal used in the cementation step, can be separated from the solution and processed separately. The copper may be recovered by, for example, electrowinning. Following the copper cementation reaction, one or more target metal, such as one or more of manganese, cobalt, and nickel, may be recovered from the depleted leach solution to provide a lithium leach solution. The separation of manganese, cobalt, and nickel from solutions is well-known in the art. As mentioned, the one or more target materials may be manganese, cobalt, and nickel and lithium. These are battery materials that are used in the production of batteries. These metals may be used in the manufacture of cathode active materials. The processing method may further include precipitating sodium sulphate from the concentrated lithium leach solution, assuming that sodium sulphate is present in solution. This may be done by cooling the concentrated lithium leach solution. The concentrated lithium leach solution may be cooled to around 5°C or less, for example from around 2 to around 4°C. The leach solution may be cooled to from around 0°C to around 6°C, around 1°C to 5°C, or around 2°C to 4°C, or 0-1 °C, or above -2 °C. The processing method may further include concentrating the lithium leach solution to form a concentrated lithium leach solution. Since the solution from which the lithium leach solution is derived needed to have sufficient volume to leach and hold the metals from the source material, as the respective metals are selectively removed from the solution, leaving primarily lithium in solution, the concentration of metal ions is decreased. As such, it is advantageous to concentrate the lithium leach solution so that a smaller volume of liquid needs to be handled and a higher extraction efficiency may be accessed. The concentration may be achieved by any method and the invention is not particularly limited by the method selected. Reverse osmosis is one example of a suitable concentration method. Another example is conventional evaporation. The processing may further include precipitating lithium carbonate from the concentrated lithium leach solution. The method may include adding one or both of sodium carbonate and ammonium carbonate to the concentrated lithium leach solution. The addition of these carbonate is to convert lithium ions in solution into lithium carbonate. The processing may further include precipitating lithium carbonate from the concentrated lithium leach solution. It will be appreciated that the lithium could be precipitated from the lithium leach solution without concentration. Whilst this would mean that there is a large volume of liquid from which to precipitate the lithium carbonate, this would avoid the concentration step, which may be advantageous in simplifying the process. The source material is preferably the black mass obtained from a mixed source material. In other words, the source materials may be a mixture of materials from different sources rather than a single type of material. Battery factory waste is material which is used to produce batteries and include offcuts, scrap, batteries which have failed quality control, as well as any other materials containing useful battery materials. Indeed, the source material may be a mixed source material, with materials from different sources being processed together as described herein. A further advantage of the present invention is that it is able to accommodate different feedstocks with different metals and different concentrations of metals, in contrast to existing methods which are limited to only particular feedstocks and do not provide the same flexibility to handle a range of feedstocks. Indeed, feedstocks can be blended deliberately to match the incoming metal composition balance with a particular product mix and / or demand plan for the various commercial offtakes. For example NMC111 feedstocks can be recycled alongside other feedstocks which result in an output which has a desired chemistry, for example NMC811. Preferably, the method does not include thermal discharge of the source material. Thermal discharge is where the material is heated up to a temperature, such as 300°C or higher for a time to remove any electric charge from the materials and / or to burn off certain materials, such as plastic or paper. Since the present invention is intended to be an environmentally-friendly solution, it is undesirable to burn off materials such as plastic or paper. In addition, thermal discharging of the source material requires additional energy to be provided, which increases cost, energy requirements, and it may also leads to losses of valuable materials such as lithium through volatilisation. Other means of dissipation could be implemented, such as electrical load discharging where a battery is connected to an electrical load to drain the battery, or by puncturing the battery and immersing it in a conductive fluid, such as brine, preferably sodium-free and / or chlorine-free brine. The solution is preferably aqueous, but can comprise an organic solvent if required. In this way removal of any chloride ions which could otherwise act as a contaminant is not required and a corrosion risk within chemical plant infrastructure designed for sulphuric acid based processes is avoided. In addition, the solution is basic in order to avoid degradation of electrolytes which may be present as these are generally fluorinated compounds, such as LiPFe, lithium hexafluorophosphate, which can release hydrogen fluoride gas, which is extremely hazardous. LiPFe is susceptible to hydrolysis in acidic media. In addition, it is preferable to avoid the use of sodium salts since these will ultimately become sodium sulphate, which has various undesirable qualities as detailed above. Preferably, chloride salts are avoided since this can attack certain grades of steel and would require a higher grade of steel to be used, which increases costs. Calcium salts are preferable since the calcium can react with any free fluoride to precipitate as calcium fluoride. The method may include separating out any remaining metallic foils, binders, membranes, separators, or plastics from black mass. Preferably, the metallic foils or plastics are removed prior to step a) of the hydrometallurgical process to minimise the amount of material which is being processed and to minimise the amount of aluminium which needs to be removed. Batteries include conductive foils, usually aluminium, and whilst these can be removed in step a) by dissolving them in acid, this increases the amount of acid required to leach the valuable battery metals from the source material, increases the amount of hydrogen H2 released during the leach process and also increases the amount of aluminium which subsequently needs to be precipitated from solution. As such, removing any foils ahead of the leaching step, is preferable. The foils may be removed by any known method, for example, eddy current, shaker table separation, sieving or filtration. Similarly, the source material may include various plastics, some of which may be readily removed by, for example, flotation, shaker table separation, sieving or filtration. Preferably, the plastics are moved by a method other than combustion or other thermal removal, such as evaporation or pyrolysis. The processing method may include adding water in step a) to provide a solid loading within a predetermined range. Since the source material needs to be mixed and transferred, this can be made easier by adding water to allow the source material to move more freely. Water may be added to provide any desired solid loading, such as 10wt% (that is the solid makes up 10% of the total mass of a given volume of the mixture of the source material and water), 15wt%, 20wt%, 25wt%, 30wt% or 40wt%. A lower solid loading will make mixing and transfer easier, but will increase the volume of liquid which needs to be handled. The processing method may further include, adding, in step a) acid in stages or steadily at a rate which controls foaming and spontaneous exothermic processes. The addition of acid, such as sulphuric acid, generates gas and foaming which needs to be kept in control. The reaction generates hydrogen gas, which must be diluted otherwise it results in a danger of explosion. In addition, the addition of sulphuric acid to water causes an increase in temperature, which also needs to be controlled to avoid overheating the solution, which can present a safety hazard and can also result in the generation of unwanted hydrogen fluoride gas. In addition, the addition of sulphuric acid to cathode metal oxides causes an increase in temperature, which also needs to be controlled to avoid overheating the solution, which can present a safety hazard and can also result in the generation of unwanted hydrogen fluoride gas. In addition, it is desirable to keep the temperature below around 85°C since in the next stage hydrogen peroxide will be added, which rapidly decomposes at elevated temperatures. The temperature may be at or below around 80 °C, 75°C, 70°C, 65°C, 60°C, 55°C, 50°C, 45°C, or less than 50 °C .The staged addition of sulphuric acid or the addition of sulphuric acid at a controlled rate avoids these issues. Furthermore, since the total amount of metals in the source material may not be known exactly, given that the method is able to accommodate a whole range of potential source materials, it is preferable to control the addition of sulphuric acid to provide sufficient time for any foaming to be observed to inform on the progress of the reaction. Similarly, controlled addition of sulphuric acid also allows for sampling of the leach solution to measure whether the concentration of one or more target metals is static, which indicates that all of the valuable battery materials have been leached into solution. In addition, it may take some time for the pH to stabilise and it is desirable that at the reasonable completion of the reaction the pH between about 0 and about 2.3 so that there is a slight excess of acid to ensure that all of the valuable battery metals have been leached and that the pH is below the pH at which certain metals begin to precipitate from solution. In step c), the temperature of the solution may be from about 40°C to about 85°C, from about 50°C to about 70°C, from about 55°C to about 65°C, or about 60°C, or about 55°C, or about 50°C, or about 45°C, or less than 50°C. These temperature ranges ensure that the peroxide does not decompose before it can react and also minimises the production of hydrogen fluoride gas. The method may include stirring or agitating at any step. It will be appreciated that it is desirable to ensure that the solution and the source materials are mixed so that the process is as efficient as possible. The oxidizing agent in step d) may be oxygen, air, or peroxide, such as hydrogen peroxide. Preferably, the oxidizing agent is oxygen or air. The oxidizing agent may be added by any suitable means, but where it is a gas, it may be bubbled through the solution. The method may include adding zinc to the depleted leach solution after step e) in order to precipitate cadmium from solution. Zinc powder may be used to precipitate cadmium (s) where ZnO is in solution as Zn2+. Cadmium may be a contaminant and, if present, it is desirable to remove this controlled element from the process. The addition of zinc causes any cadmium to precipitate out of solution, from which it can be removed and disposed of safely. One, two or all of manganese, cobalt, and nickel may be recovered from the depleted leach solution via solvent extraction. Solvent extraction of these elements from solution is known in the art, and the present invention is not particularly limited by the way in which this is achieved. For example, manganese may be removed from solution using Di(2-ethylhexyl)phosphoric acid (DEHPA) and kerosene. Cobalt may be removed from solution using Cyanex 272™ and kerosene. The pH of the solution may be adjusted using an acid, such as sulphuric acid, and one, two, or all of sodium hydroxide, ammonium hydroxide, lithium hydroxide, nickel hydroxide, manganese hydroxide, or cobalt hydroxide, preferably wherein the nickel hydroxide, lithium hydroxide, cobalt hydroxide, and / or manganese hydroxide is a recycle stream at least partially obtained from the depleted leach solution. By using a recycle stream, it is possible to reduce the amount of additional chemicals which need to be used in the process. The pH may be selected such that greater than 50% of a target material is extracted in the solvent extraction step. The solubility of different metals depends on the pH and by adjusting the pH of a solution, it is possible to control which metal is preferably extracted. Nickel may be precipitated from the pregnant leach solution with a mixture of ammonium hydroxide, lithium hydroxide, and / or sodium hydroxide. Whilst it is desirable to minimise the amount of sodium being used in the method, nickel co-ordinates with ammonium hydroxide, so it is preferable to use ammonium hydroxide to precipitate out the nickel alongside one or both of sodium hydroxide and lithium hydroxide. Even so, some ammonium hydroxide can be used to reduce the amount of sodium being introduced. The pH of the depleted leach solution may be increased to about 7 to about 11, to about 8 to about 10, to about 8.5 to 9.5, or to about 9 to 9.5 in order to precipitate nickel. The processing method may further include combining one or more of any recovered manganese, cobalt, and nickel in a predetermined ratio and precipitating out the one or more of the recovered manganese, cobalt, nickel, and lithium to form a cathode active material precursor precipitate, optionally wherein the method further includes supplementing one or more of the recovered manganese, cobalt, and nickel with additional manganese, cobalt, and / or nickel. By precipitating these metals out of solution together, they are much better mixed that would be the case were they to be mixed as solids. The metals may be precipitated as carbonates. Since the source material may not include these metals in the exact ratio required to produce a cathode active material, supplemental metals can be includes in order to provide the desired ratio. Such supplemental metals may be provided as the sulphate of the metals. For example, the ratio of manganese, nickel, and cobalt can be adjusted to any required battery chemistry, such as, for example, NMC 111, NMC 622, NMC811, NMC 532, or any intermediary ratio blends. The processing method may further include converting the cathode active material precursor precipitate into a cathode active material. This may include one or more calcining steps to convert the cathode active material precursor precipitate into a cathode active material. The precipitated Ni, Mn, Co carbonate may be filtered, dried, and milled before undergoing a pre-calcining step. Following pre-calcining, lithium hydroxide may be added, the mixture milled again, followed by final calcining. The processing method may include incorporating lithium, optionally in the form of lithium hydroxide, after a pre-calcination step. This step forms what is commonly referred to as green body, which is a mixture of lithium hydroxide and oxides of nickel, manganese, and cobalt. This green body can then be calcined at elevated temperatures in an oxygen enriched atmosphere to form the final cathode active material. The processing method may include one or more mixing, grinding, or milling steps. Whilst such steps may take place at any stage where it is desirable to break down solids into smaller pieces, this step will most likely be conducted after the cathode active material precursor precipitate has been dried, after it has been pre-calcined, and / or after it has been calcined. Any suitable mixing, grinding, or milling process may be used and the present invention is not particularly limited by the method used, for example, dry or wet planetary ball milling, rolling ball milling, high shear milling, air jet milling, and / or impact milling. The method may include one or more filtration steps. The filtration step may take place at any stage where it is desirable to separate a solid from a liquid. Any suitable filtration process may be used and the present invention is not particularly limited by the method used. It will be appreciated that there may be provided an apparatus for recovering material from a source material containing one or more target metals, preferably one or more of manganese, cobalt, nickel, and lithium, the apparatus including a one or more vessels configured to perform the method of the first aspect of the present disclosure. The apparatus may include any features suitable for carrying out the steps of the method. It will be appreciated that features described in respect of one aspect may be combined with any features described in respect of another aspect and all such combinations are expressly considered and disclosed herein. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawing in which corresponding reference symbols indicate corresponding parts, and in which: Figure 1 is a schematic flowsheet depicting a method of generating black mass according to an aspect of the present disclosure; Figure 2 is a schematic flowsheet depicting a method of generating black mass according to an aspect of the present disclosure including a divided first stream; Figure 3 is a schematic flowsheet depicting a method of generating black mass according to an aspect of the present disclosure including a water recycle; Figure 4 is a schematic flowsheet depicting a method of generating black mass according to an aspect of the present disclosure including an oversize particle recycle; Figure 5 is a schematic flowsheet depicting various steps in the hydrometallurgical processing method of the present disclosure; Figure 6 is a schematic flowsheet depicting various subsequent steps in the hydrometallurgical processing method of the present disclosure; Figure 7 is a schematic flowsheet depicting various further subsequent steps in the hydrometallurgical processing method of the present disclosure; Figure 8 is a schematic flowsheet depicting yet further various subsequent steps in the hydrometallurgical processing method of the present disclosure; and Figure 9 is a schematic flowsheet depicting yet further various subsequent steps in the hydrometallurgical processing method of the present disclosure. The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements. It will be appreciated that features depicted and described in respect of one aspect of the present disclosure may be combined with any feature described in respect of any other aspect of the present disclosure. Figure 1 depicts a schematic flowsheet depicting various steps in the method of generating black mass according to the present disclosure. In the method, a mixed feedstock 1 is received and separated 2 into a first stream 3 comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture 5. It will be appreciated that waste from battery manufacture includes battery materials that may have not been formed into complete cells or batteries. Additionally, the mixed feedstock can be screened for any chemistries less suitable for any particular batch process for a selected chemistry stream. The first stream 3 is shredded in a wet shredding step 4 to provide a wet shredded stream 7. At this stage of post wet shredding, any broken away black mass containing materials having higher grade black mass, can be removed for fast tracking. The second stream 5 is shredded in a dry shredding step 6 to provide a dry shredded stream 8. The method includes combining the wet shredded stream 7 and the dry shredded stream 8 to form a combined stream 9. The combined stream 9 is then processed 10 to form a black mass stream 11. The black mass stream 11 may be provided to a processing system to extract valuable materials therefrom and the black mass graded accordingly. Figure 2 is similar to Figure 1 with the difference that the method includes separating the first stream 3 into a first substream 3’ including EV batteries and a second substream 3” including the remaining batteries via separation step 12. The first and second substreams 3’, 3” are then shredded in separate shredding steps 4 to form wet shredded streams 7’, 7”. As with the embodiment of Figure 1, the wet shredded streams 7’, 7” are combined with the dry shredded stream 8 to form combined stream 9. Figure 3 is similar to Figures 1 and 2 with the difference that the method includes a recycling step 13 in which water from the processing step 10 is recycled back to the wet shredding step. It will be appreciated that although Figure 3 depicts an embodiment in which the first stream 3 has been divided into two substreams 3’, 3”, the water recycling step 10 may equally be applied in method where the first stream 3 is not divided, as shown for example in Figure 1. Figure 4 is similar to Figures 1 to 3 with the difference that the method includes screening step 14 in which shredded materials from the wet and / or dry shredding steps 4, 6 is screened for size, with oversized particles being recycled 15 back into respectively wet or dry shredding steps 4, 6. Again, it will be appreciated that although Figure 4 depicts an embodiment in which the first stream 3 is not divided into separate substreams 3’, 3”, that the method step of screening and recycling may equally be applied to embodiments in which the first stream 3 is divided. It will also be appreciated that any of the features of Figures 1 to 4 may be combined. For example, the method may include dividing the first stream into two or more substreams, screening and recycling oversize particles, and recycling recovered water to the wet shredding step. Figure 5 is similar to Figures 1 to 4 and includes each of the differential steps described in Figures 1 to 4. In particular, the method includes receiving a feedstock 1 including one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or other electrochemical energy storage devices. The feedstock is separated 2 into a first stream 3 comprising batteries or other electrochemical energy storage devices and a second stream 5 comprising waste from battery manufacture. It will be appreciated that waste from battery manufacture includes battery materials that have not been formed into complete cells or batteries. The method also includes separating the first stream 3 into a first substream 3’ including EV batteries and a second substream 3” including the remaining batteries or other electrochemical energy storage devices, such as capacitors. The first and second substreams 3’, 3” are then shredded in separate shredding steps 4 to form wet shredded streams 7’, 7”. As with the embodiment of Figure 1, the wet shredded streams 7’, 7” are combined with the dry shredded stream 8 to form combined stream 9. Although it is depicted that the two wet shredded streams 7’, 7” are combined prior to combination with dry shredded stream 8, the invention is not particularly limited by this and the different wet and dry shredded streams may be combined with one another in any order. The method also includes screening step 14 in which shredded materials from the wet and / or dry shredding steps 4, 6 is screened for size, with oversized particles being recycled 15 back into respectively wet or dry shredding steps 4, 6. It will be appreciated that oversized particles from the dry shredding step may be recycled back to the dry or wet shredding step, whereas oversized particles from the wet shredding step are preferably recycled only back to the wet shredding step. The method also includes a recycling step 13 in which water from the processing step 10 is recycled back to the wet shredding step. Although in the depicted embodiment, the recycling step 13 is shown as only providing recycled water to one of the wet shredders, it will be appreciated that the invention is not particularly limited to this and the method may include recycling water back to any number of wet shredders. The combined stream 9 is then processed 10 to form a black mass stream 11. The black mass stream 11 may be provided to a processing system to extract valuable materials therefrom. Black mass generated can then be categorized according to a grading system, and differentiate between quality of black mass as primary, secondary and tertiary, or high nickel black mass. As depicted in Figure 5, the apparatus includes a separator 2 configured to separate the feedstock 1 into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture. The separator may separate the feedstock by any suitable method. Once such method is determining the weightvolume ratio of any electrochemical energy storage devices, particularly batteries in the feedstock, measuring volumetric energy density (mass / volume) in kg / l for the mixed incoming feedstock. As can be seen from Table 1 below using identified example battery packs from on the road cars, and known data from capacity, energy and voltage, as identified from basis packs from identified vehicle packs. This information can be determined without dismantling the battery pack without requiring significant analysis. The ranges shown in the Table are the ranges obtained when the cell and pack volumes are known. Cell values are important values relevant for sorting on a conveyor. Table 1 Illustrates the decrease in specific energy and energy density of LFP and NCA technologies, from their theoretical potential (“Theory”) to the practical implementation in an installed automotive battery pack. Despite a notable contrast in specific energy (Wh / kg) and energy density (Wh / L) at the cell level, both technologies exhibit preferentially differentiated performance when evaluated at the pack level. There have been identified that cells built or transferred into a battery pack significantly or measurably different and readily usable to differentiate battery packs sufficiently for control of composition for abatement through various recycling routes. Even at pack level it is possible to tell them apart accounting for the packaging. There is a difference in the volumetric weight of batteries having NMC chemistry and batteries having LFP chemistry. In this way, it is possible to screen the cell chemistry of individual batteries. Table 1 Measurement of performance Theory Cell level Pack level NMC LFP NMC LFP NMC LFP Specific Energy (Wh / kg) 700 / 850 350-370 250 / 260 160-180 135 130- 140 Energy Density (Wh / I) 2400 / 2600 1100 / 1300 700 / 750 330—380 250-280 200- 230 Volumetric weight (kg / l) - - - - 1.85-2.07 issue The apparatus further includes means for dividing the first stream into first and second substreams. The invention is not particularly limited by the means by which the first stream is divided and any means as known in the art which is capable of dividing a stream into two or more substreams may be utilised. The apparatus also includes first and second wet shredders 4 configured to receive the respective first and second substreams. The first and second wet shredders are configured to shred the material fed into them to produce a wet shredded material. The first and second wet shredders are configured to pass the wet shredded material streams into one or more screens 14 configured to separate shredded material of different sizes. Any oversized material is passed back to the wet shredders for re-shredding. Material which is of the desired size is combined with dry shredded material and passed to an apparatus configured to separate black mass therefrom. Figure 6 depicts a first flowsheet depicting various steps in the method according to the present invention. It will be appreciated that this flowsheet preferably follows the method / apparatus of figures 1 to 5 and may be configured to indirectly or directly receive black mass as an input therefrom. By directly receive, it is to be understood that the two methods / apparatuses are connected without any intermediate storage or transportation of the black mass. By indirectly receive, it is to be understood that the two methods / apparatuses may be separated by one or more intermediate steps, such as storage or transportation. In the method of the invention, a source material 111, which may be black mass, a blended mixed feedstock, or any other source material as described herein, is provided. Water 113 is combined the source material 111. The water is added in an amount calculated depending on the amount of course material as well as the desired solid loading. Acid 112, such as sulphuric acid, is also combined with the mixture of water 113 and source material 111 in order to begin leaching metals from the source material 111. This acid leaching step is preferably conducted at from around 40 to around 80°C, and may be conducted at less than 50°C. The initial leaching step is monitored to determine when the leaching is complete. The pH of the solution is from 0 to 2.3 to ensure that the metals are retained in solution. The monitoring is done by any one or more of the methods described herein. For example, since the reactions which leach metals into solution also generates gases, the foaming of the solution can be observed to determine when the reaction is complete. The acid vapours, which include any HF produced as well as any hydrogen gas produced are taken away for further processing. After the initial leaching step has been completed, as indicated by a cessation of foaming, the concentration of one or more metals being constant, the pH indicating that no more acid is being used up in chemical reactions, or a total calculated amount of acid being added, and wherein the pH is between 0 and 2.3, hydrogen peroxide is added to the solution until the reaction has reached completion and wherein the pH is between 1 and 2.3. Additional acid may optionally be added if the pH rises above 2.3 during the second stage of the leaching, namely the addition of the reducing agent, preferably hydrogen peroxide. The hydrogen peroxide may be 30% hydrogen peroxide, although other concentrations can also be used. The temperature is kept below 85°C in order to avoid premature decomposition of the hydrogen peroxide. A greater than stoichiometric amount of the sulphuric acid 112 and hydrogen peroxide 115 are added to ensure that all of the metals are leached into solution. In order to avoid unnecessary usage of chemicals, the amounts added are just over stoichiometric. In other words, the amount of acid / peroxide added is greater than the stoichiometric amount required to leach all of the target metals into solution. The sulphuric acid 112 and hydrogen peroxide 115 are preferably added either in batches or at a controlled rate, rather than all at once, in order to control the reaction. Once the metals are leached into solution, graphite 116 and any other remaining solids are filtered out of the solution. The graphite 116 is unaffected by the leaching step and so the graphite phase retains the morphology and particle size required to act as new anode material, such as greater than 5 microns, without requiring an energy intensive fusion process step to regrow crystallites. The solution is then neutralised through the addition of a base. The base may be provided as a fresh base from outside the process, or may be a recycle stream including a basic solution or compound from a later stage of the process. The pH of the solution is increased to around a pH of 4 to 6 at a temperature of from around 30 to around 60°C. This causes gypsum (if the base includes calcium), iron, and aluminium to precipitate out of solution, which can be filtered off 118. If calcium hydroxide is used as a base, this will also precipitate out, likely as calcium fluoride. Following the filtration step 118, there is a copper cementation step 119. The copper cementation step 119 removes any copper present in solution and is achieved by the addition of metallic iron and an oxidiser, such as air. This causes copper metal to precipitate from solution as well as iron oxides. The solids may be filtered out in step 110 and the copper may be separated and recovered by electrowinning. This forms depleted pregnant leach solution 211, which including any nickel, cobalt, manganese, and lithium, but has been depleted of any copper, iron, or aluminium as intermediary metals. As shown in Figure 7, the depleted pregnant leach solution 211 is then passed to a series of extraction steps 212, 213, 214 to selectively remove manganese, cobalt and nickel from solution. The solvent extraction of manganese takes place first in line with standard practice and includes the addition of sulphuric acid, a solvent extraction base, water, DEHPA, and kerosene. This creates a manganese-loaded DEHPA / kerosene stream 215 from which manganese sulphate 216 can be removed, which forms a stripped DEHPA / kerosene stream 217, which is recycled back in order to extract further amounts of manganese from the depleted pregnant leach solution 211. This step can be repeated as many times as required. Once the manganese has been stripped out, cobalt is then stripped out in another solvent extraction step 213. Cobalt is extracted in line with standard practice and includes the addition of sulphuric acid, solvent extraction base, water, and Cyanex 272™ and kerosene. Cyanex 272™ is a trimethylpentylphosphonic acid. This creates a cobalt loaded Cyanex™ / kerosene stream 218 from which cobalt sulphate 219 can be removed, which forms a stripped Cyanex™ / kerosene stream 220. The stripped Cyanex™ / kerosene stream 220 is recycled back in order to extract further amounts of cobalt from the depleted pregnant leach solution 211. This step can be repeated as many times as required. The solvents used in solvent extraction are highly recyclable and can be used multiple times without total replacement. Although some may be destroyed or lost, only a small amount will need to be added to replace any lost solvent. The solvent may be dearomatised so that any catalytic decomposition with the metal ions is minimised, thereby extending the lifespan of the solvent. Once the manganese and cobalt have been extracted, a nickel precipitation step 214 is conducted by including a base to adjust the pH of the depleted pregnant leach solution 211 to cause the nickel to be precipitated. The precipitated nickel is filtered in a filtration step 221 to form a lithium leach solution 222. As shown in Figure 8, the lithium leach solution 222 is concentrated in concentration step 223. This can be achieved by, for example, reverse osmosis. Any demineralised water 224 can be recycled into the process at any stage where water is required. Indeed, any process stream which yields a solid product and the liquid by-product is available for recycling into an earlier stage requiring water. Residual concentrations in solution can re-enter the process flow at the appropriate stage to allow for recovery based on the contaminant profile, which leads to increased net recovery rates. Any filtered solids may be washed with fractions of water from the process and washings may be recovered either to an earlier or a later stage of the process. Any aqueous stream may be concentrated, such as by reverse osmosis or evaporation, with the collected purified water being used again, thereby reducing the overall volume of process waste Concentration of the lithium leach solution 222 is optional. Prior to the concentration step 223, there may be a sodium sulphate precipitation step 225. The concentrated lithium leach solution is passed to a sodium sulphate precipitation step 225 in which any remaining sodium sulphate is precipitated out by cooling the concentrated lithium leach solution. Although depicted as following the lithium concentration step 223, additionally or alternatively, there may be a sodium sulphate precipitation step 225 before the concentration step 223. The sodium sulphate is filtered out in filtration step 226. Following on from sodium sulphate precipitation and filtration, the remaining solution is passed to a lithium carbonate precipitation step 227 in which carbonates are added to react with lithium in solution and cause it to precipitate out as lithium carbonate. The lithium carbonate is filtered out to provide a lithium carbonate product 228. The lithium carbonate 228 may be passed to a third party for conversion to lithium hydroxide or the process may include a further step of converting the lithium carbonate 228 to lithium hydroxide. A final depleted leach solution 229 now depleted of all target metals may be taken off for further processing. As shown in Figure 9, nickel hydroxide 230, manganese sulphate 216, and cobalt sulphate 219 are blended with water and co-precipitated in a co-precipitation step 231 by the addition of a carbonate precipitant 232 to form a cathode active material precursor precipitate 233. Additional manganese, cobalt, and / or nickel may be added to adjust the ratio of these metals as required. Following co-precipitation, the co-precipitate is filtered and dried in a filtration and drying step 234. The cathode active material precursor precipitate 233 may undergo milling. For example, dry or wet planetary ball milling, rolling ball milling, high shear milling, air jet milling, and / or impact milling or spray drying. The cathode active material precursor precipitate 233 is pre-calcined in a pre-calcination step 35 at a temperature of around 350 to 500°c in air or oxygen to oxidise the cathode active material precursor precipitate 233. The pre-calcination step 235 may take place for as long as required to oxidize the cathode active material precursor precipitate 33 to form NMC oxides and oxidise any residual carbon in the matrix 236. Following pre-calcination, the NMC oxides 236 are blended with lithium hydroxide in a blending step 237 to form a lithium hydroxide / NMC oxide green body 238. The green body 238 is then calcined in a calcination step 239 to form a final cathode active material 240. It will be appreciated that any of the liquid streams may be recycled back to an earlier stage of the process in order to improve the amount of target metals extracted. In addition, basic liquid streams may be fed back into the system at stages where the pH needs to be increased. It will also be appreciated that any of the tanks may include one or more sensors to measure the temperature, pH, or any other characteristic of the liquid at any stage of the process, such as a colourimetric sensor to detect the composition of the solution. The figures are shown without scale. In summary, the present invention provides a method and apparatus for generating black mass from a mixed feedstock. Batteries and other electrochemical energy storage devices are shredded via wet shredding in order to abate the risks of fluorinated compounds or explosion or fire, and materials that have not been finally assembled into batteries, and which therefore do not require fluorine or fire abatement are shredded separately via dry shredding. The wet and dry shredded materials are combined prior to processing to separate black mass from the combined mixture since the downstream process of separating black mass from the remaining materials is more efficient with a higher solids loading than is possible via a wet shredding step. This allows for a more efficient process of generating black mass thereby creating more high quality black mass, and also reduces costs since the plant would utilise smaller shredders, dry shredders require less electricity to operate, and the area of the plant may be smaller. The present invention also allows for screening of cell chemistries, which allows improved control of throughput through the process and control of the mix of cell chemistries being processed.

Claims

1. A method of generating black mass, the method including the steps of:a) receiving a feedstock from which black mass is to be recovered, the feedstock including one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or other electrochemical energy storage devices;b) separating the feedstock into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture;c) shredding the first stream in a wet shredder to form a wet shredded stream;d) shredding the second stream in a dry shredder to form a dry shredded stream;e) combining the wet shredded stream and the dry shredded stream to form a combined stream;f) processing the combined stream to form a black mass stream.

2. The method according to claim 1, wherein the method includes measuring one or more parameters of batteries within the feedstock to determine the likely cell chemistry of the batteries.

3. The method according to claim 2, wherein measuring one or more parameters of batteries within the feedstock include measuring the physical dimensions of the batteries, measuring the weight of the batteries, measuring an elemental composition of the batteries, and / or comparing images of the batteries to a database of images or any other method able to identify a battery.

4. The method according to claim 2 or claim 3, wherein the method includes determining a weightvolume ratio of the batteries to determine the likely cell chemistry of the batteries.

5. The method according to any preceding claim, wherein the method of separating the feedstock into a first stream and a second stream includes diverting the feedstock onto separate conveyors.

6. The method according to any preceding claim, wherein the method includes separating the first stream into a first substream and a second substream.

7. The method according to claim 6, wherein the first substream includes EV batteries and the second substream includes the remaining batteries.

8. The method according to claim 7, wherein the first substream and the second substream are shredded in separate shredders.

9. The method according to any preceding claim, wherein the shredding is conducted such that shredded material has the same passing size.

10. The method according to any preceding claim, wherein the wet shredding step includes shredding the first stream at least partially submerged.

11. The method according to any preceding claim, wherein the method includes at least partially dewatering the black mass stream from step f), optionally wherein the water is recovered to the wet shredding step.

12. The method according to any preceding claim, wherein the method further includes screening the wet shredded stream and / or the dry shredded stream, and passing oversized materials back into a shredding step.

13. An apparatus for generating black mass, the apparatus including:a) a separator configured to separate a feedstock including one or more of EV batteries, power electronics batteries, consumer batteries, waste from battery manufacture, or other electrochemical energy storage devices, into a first stream comprising batteries or other electrochemical energy storage devices and a second stream comprising waste from battery manufacture;b) a wet shredder configured to receive and shred the first stream to form a wet shredded stream;c) a dry shredder configured to receive and shred the second stream to form a dry shredded stream;d) a mixer configured to combine the wet shredded stream and the dry shredded stream to form a combined stream; ande) a processing apparatus configured to separate black mass from the combined stream.

14. The apparatus according to claim 13, wherein the apparatus includes an identifier configured to identify the likely cell chemistry of the batteries in the feedstock.

15. The apparatus according to claim 14, wherein the identifier is configured to measure one or more parameters of batteries within the feedstock include measuring the physical dimensions of the batteries, measuring the weight of the batteries, measuring an elemental composition of the batteries, or comparing images of the batteries to a database of images.

16. The apparatus according to claim 14 or claim 15, wherein the identifier is configured to determine a weightvolume ratio of the batteries to determine the likely cell chemistry of the batteries.

17. The apparatus according to any of claims 13 to 16, wherein the separator includes a further separator connected to two or more output conveyors.

18. The apparatus according to any of claims 13 to 17, wherein the apparatus is configured to divide the first stream into a first substream including EV batteries and a second substream including the remaining batteries.

19. The apparatus according to claim 18, wherein the apparatus includes separate shredders for the first substream and the second substream.

20. The apparatus according to any of claims 13 to 19, wherein the shredders are configured to provide shredded material having the same passing size.

21. The apparatus according to any of claims 13 to 20, wherein the wet shredder is configured to shred the first stream as it is at least partially submerged.

22. The apparatus according to any of claims 13 to 21, wherein the processing apparatus includes at least one dewaterer configured to at least partially dewater the combined stream.

23. The apparatus according to any of claims 13 to 21, wherein the apparatus includes one or more screens configured to selectively separate shredded material depending on size, optionally further including a recycle path for passing oversized materials back into a shredder.

24. A battery recycling system comprising the apparatus according to claims 13 to 23.

25. The battery recycling system according to claim 24, wherein the battery recycling system further includes a hydrometallurgical processing system for processing black mass.

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