Material recovery method and use

Abstract

A method of recovering metals from a source material (e.g. lithium battery waste) by adding acid to the source material, and then adding a reducing agent (e.g. a peroxide) to the leach solution while maintaining its temperature at 85 0C or less. While the acid and reducing agent are added, one of foaming, the rate of change of leach metal concentration in the solution, the rate of change of pH or the initial concentration of a leach metal is monitored. The addition of acid and reducing agent are respectively stopped when i) all target metals have been solubilised and the pH is between 0-2.3 and ii) the pH is between 1-2.3. A base is then added to increase the pH to 5 to 5.3 along with an oxidising agent (air or oxygen) to remove metals such as iron and aluminium. Metals can be recovered from the depleted leach solution. Apparatus for performing the method comprise a leach tank with an agitator and a foam breaker on a common shaft and a recirculation loop for spraying liquid from the tank onto foam in the tank. Also hydrometallurgically recovered graphite with crystallites having a minimum ferret diameter of 5 microns.

Description

The present invention relates to a method, leach tank, apparatus, system, and use of such method, leach tank, apparatus or system for recovering material from a source material comprising one or more target metals, such as one or more of manganese, cobalt, nickel, and lithium or target battery intermediary materials or metals. The present invention also relates to various compositions produced according to the methods described herein. The present invention has particular, but not exclusive, application to the sustainable recovery of battery materials from the sourcing of raw material to battery intermediary materials to a battery ready blended composition, from a wide ranged variation in mixed source material, such as recycled batteries (of all chemistries), preferably, but not exclusively, lithium batteries, lithium ion batteries, or virgin feedstock from mines, black mass, battery factory waste or scrap, precursor battery materials, mixed metal hydroxide precipitates, and combinations thereof. The present invention relates to a full circularity model with pre-processing steps, black mass recycling and chemical refining to electrode active materials for direct reuse in an EV supply chain. Recovered materials may be recycled, re-engineered, and upcycled with a reduced carbon footprint and reduced cost compared with virgin materials. The present invention relates a system for recycling having a number of tanks configured to extract one or more target metals from a material and selectively separate them from one another. 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 defossilize the global energy supply chain in order to meet net-zero goals, the materials that are used to create batteries to power the defossilization of the world’s economy are in ever increasing demand as sourcing of critical minerals and metals become ever more 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, especially EV batteries. Batteries have a limited lifespan and eventually need to be recycled. There are a number of existing ways in which batteries are recycled to recover useful materials. 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 documents describe deactivating raw comminuted material through heating. EP2784166 describes a method for producing high-purity nickel sulphate and includes obtaining a precipitate of nickel sulfide, which is then prepared as a slurry to which an oxidising agent is added at a temperature of from 60°C to 180°C. An alkali is added to the solution to neutralise the solution to a pH of from 5.0 to 6.0 to remove iron. Solvent extraction forms a stripped liquid and a nickel sulfate solution. EP3907182 describes a process in which copper in solution is recovered via electrolysis to reclaim copper and in which iron is precipitated out as iron phosphate by increasing the pH of the solution to greater than 14, to obtain lithium iron phosphate precursor. WO2022154316 describes the preparation of a cathode active material from a cathode of a lithium secondary battery. A first leachate is generated by treating the material with an acidic solution containing a reducing agent in a sub-stoichiometric amount, and then treating a second leachate with a second acidic solution containing a reducing agent. Whilst existing methods do allow for the recovery of valuable battery materials, such as manganese, cobalt, nickel, and lithium, they either use concentrated acids directly on materials to leach metals from the materials, which are dangerous to handle and can cause uncontrolled heating should any water be present, use high temperatures and very low amounts of water content to degrade fluorine-containing compounds which generates large amounts of dangerous HF gas which needs to be carefully extracted from waste gas streams, or they use electrolysis, which relies on the use of expensive electrical power. In addition, existing methods are not flexible regarding the composition of any mixed comminuted material from processing of multiple battery chemistries at the same time and so there is nothing in the existing methods which can take account of variation in the feedstock which contains the valuable battery materials as they rely on a single source material and each single process is battery composition specific. Existing methods are not sufficiently optimised to remove impurities (removing uncontrolled co-precipitation contaminating pure products). The present invention removes hazards thereby improving safety, in a cost effective way, whilst optimising recovery up to better than 99% of target metals leached from the source material, of a range of critical materials with higher purity grades. 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 recovering material from a source material 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, which preferably contain one or more of manganese, cobalt, nickel, and lithium, such as batteries, mixed hydroxide precipitates, or scrap from battery manufacturing often contain other materials or metals such as aluminium, iron, copper, graphite, 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, such as the present invention. 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 leads to the production of hydrogen fluoride gas from fluorinated compounds in the source material, 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 uses up the acid, this will drop over time. Staged addition of further acid will at least partially replace any acid which has been used up 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 present method includes adding water to the source material 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 in the various stages of the present disclosure. 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, 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. 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 method includes 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 method further includes 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 method includes 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. The method 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 1.15 times 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 method is primarily a batch process. The method further includes 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 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 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 further includes 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, to oxidise iron, or other metal, in solution, which can precipitate out as iron (III) oxy-hydroxide. 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 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. The 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. The method 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 method 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 may include one or more of black mass, batteries, preferably lithium-containing batteries, battery factory waste, precursor battery materials, and mixed hydroxide precipitates, or mixtures thereof. As such, the source material may be 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. 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. The method may further include, prior to step a), contacting shredded lithium-containing batteries and / or source material with a basic aqueous solution of an alkali metal salt or alkali earth metal salt. The method may include, prior to step a), brine discharging of the source material to dissipate any electrical charge. This may be achieved by submerging any batteries in a brine to electrically discharge them. The batteries may be dry shredded or wet shredded. Preferably the alkali metal salt or alkali earth metal salt is not a chloride. Preferably, the alkali metal is other than sodium. The source material may include materials which retain some electrical charge. By contacting the source materials with a basic solution of an alkali metal salt other than sodium chloride or indeed any other sodium salt, the charge may be dissipated. 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 and also energy requirements. 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 generally stable, but 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 further include recovering the basic aqueous solution after contacting the basic aqueous solution with the source material. By separating the basic aqueous solution and any remaining solids, the solids can be passed into step a), optionally after being washed, and the basic aqueous solution can be taken away for further processing, if required. The separation can be done by any suitable means, such as filtration or centrifugal separation. The method may include separating out any metallic foils, binders, membranes, separators, or plastics from the basic aqueous solution. Preferably, the metallic foils or plastics are removed prior to step a) 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 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% or40wt%. A lower solid loading will make mixing and transfer easier, but will increase the volume of liquid which needs to be handled. The 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 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 dangerous 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 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. 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 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 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 oxygen to form the final cathode active material. The 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, roiling 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. According to a second aspect of the present disclosure, there is provided a leach tank for leaching a material from a source material comprising one or more target metals, the leach tank comprising: a tank defining a volume; an agitator configured to stir liquid within the tank; a foam breaker configured to break foam within the tank; a recirculation loop configured to transfer liquid from within the tank to spray down foam within the tank. It is desirable to leach as much of the valuable metals from a source material as possible and so stirring the liquid within the tank allows the metals to be efficiently leached into solution. The leaching process generates gases which cause the liquid to foam and bubble. It is desirable to knock back any foaming and this may be achieved in a number of ways. Firstly, a foam breaker is provided that is able to physically break any foam. In addition, it is possible to take fluid from within the tank and spray it onto the foam in order to break the foam. The agitator and the foam breaker may be attached to a common shaft. The common shaft may be connected to a motor configured to rotate the shaft and thereby rotate the agitator and the foam breaker. The foam breaker may be in the form of a flail, an arm, a chain, or a disc which rotates with the shaft to impact any foam and cause it to break. The agitator may be in the form of a paddle or impeller to cause liquid within the tank to circulate and mix. The tank may include one or more sensors configured to measure a parameter of liquid within the tank. The one or more sensors may be a pH sensor, a temperature sensor, or a fill level sensor. It is useful to measure the parameters of a liquid within the tank for safety reasons as well as process control reasons. Since the pH needs to be controlled such that metals that are leached into solution remain in solution until it is desired to remove them, then the pH of liquid within the tank may be measured. In addition, since, in some embodiments, the progress of the reaction and the decision as to when to stop adding acid depends on measuring the rate of change of pH, since the pH will be static once all of the metals have been leached into solution and addition of further acid will decrease the pH, it is useful to measure the pH. Since it is desirable for the temperature of the reaction within the tank to be maintained at 85°C or less to avoid decomposition of peroxide, it is useful to measure the temperature within the tank. It is also important to measure a level of liquid within the tank and so a fill level sensor is useful. Any type of fill level sensor may be used. The tank may include an offtake branch configured to withdraw sample of liquid for testing. It may be desirable to extract a sample of liquid within the tank to measure a parameter of the liquid, such as to measure a concentration of one or more metals within the liquid, a means of withdrawing a sample of liquid may be provided. The tank may be a jacketed tank. A jacketed tank is one which includes a jacket at least partially surrounding the tank defining the volume in which the leaching takes place and is configured to control the temperature of liquid within the tank. The tank may include one or more inlets configured to provide one or more of a source material, acid, water, and a reducing agent into the volume. Such materials may be provided by one or more common inlets or by individual inlets. The tank may include one or more outlets configured to discharge one or more of offgas and a pregnant leach solution. The leaching reaction generates gases, including hydrogen gas, that needs to be taken away for further treatment and / or disposal. The tank may include an acid-resistant lining, such as PTFE. Since the conditions within the leach tank are acidic, the interior of the tank needs to be resistant to acids. Whilst tank materials such as stainless steel are resistant to some extent, the provision of an additional inert layer serves to extend the operational lifespan of the tank. According to a third aspect of the present disclosure, there is 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. The apparatus may comprise: i. an energy dissipater to immerse the battery into a basic aqueous solution of alkaline or alkali metal salt; ii. a separator to separate non-metals including metallic foils, plastics from the aqueous solution; iii. a leaching vessel including inlets to add water and acid to leach target metals to form a pregnant leach solution; iv. a first precipitation vessel including an inlet to add a base; v. a cementation vessel including inlets to add metallic iron and an oxidiser; vi. a solvent extraction vessel to solvent extract one or more target metals into separate streams. Optionally, the apparatus further includes: vii. a concentrator configured to remove water from a solution. The concentrator may be any suitable apparatus for removing water from a solution, such as vie reverse osmosis, or evaporation. The apparatus may further include: viii. a sodium sulphate removal vessel. The sodium sulphate vessel may include a cooler. The cooler is configured to lower the temperature of any solution containing sodium sulphate, thereby causing the sodium sulphate to crystallise out of solution. The apparatus may further include: ix. a lithium precipitation vessel. The lithium precipitation vessel may include an inlet for the addition of a carbonate. The carbonate reacts with lithium in solution to precipitate lithium carbonate, which may be recovered. The apparatus may further include: x. a co-precipitation vessel for producing a coprecipitate. The co-precipitation vessel may include respective inlets for the addition of different solutions. The different solutions may be added in a desired ratio. The apparatus may further include: xi. a milling apparatus. The milling apparatus may be configured to mill a co-precipitated mixture from the co-precipitation vessel. The apparatus may further include: xii. a calcining oven. The calcining oven may be configured to partially or fully calcine a precursor cathode active material into a cathode active material. The apparatus may include one or both of a vessel to dissipate any electrical energy from the source material prior to step i), which optionally comprises a brine, and ii) a machine for puncturing or pierce a battery precursor material to release electrolyte As such, there is provided an apparatus including a leaching vessel configured to leach one or more target metals from a source material using an acid and a reducing agent, a precipitation vessel configured to precipitate one or more intermediary materials or metals from solution, a further precipitation vessel configured to precipitate any copper from solution, and a solvent extraction system configured to selectively separate target metals into separate streams. The solvent extraction system may include a plurality of solvent extraction vessels, optionally including one or more recycle lines. The leaching vessel may be a leaching tank in accordance with any aspect of the present disclosure. The apparatus may include a vessel configured to discharge any batteries which are to be passed into the leaching vessel. Since the source material may include batteries which retain some electrical charges, it is desirable to discharge them, such as by immersion in a conductive fluid such as a brine. Another way of discharging the batteries may be via connection to an electrical load. The apparatus may include a shredder configured to shred source material, such as batteries, or indeed any other source material that is advantageously shredded. By shredding the materials, the valuable metals and other materials which are to be recovered are accessible. The apparatus may include a puncturing device configured to puncture a battery to release electrolyte therefrom. The electrolyte may be separated from the rest of the battery prior to the material being subject to leaching. The electrolyte often includes organic materials and fluorinated compounds, which are desirable to remove. The apparatus may include a separator configured to separate any non-metals, such as plastics or foils from the source material. The separator is preferably upstream of the leaching vessel, but could optionally be included in the leaching vessel. The apparatus may include a co-precipitation vessel configured to co-precipitate one or more target materials, preferably nickel, manganese, and cobalt, to form a co-precipitate. The apparatus may include a pre-calcination vessel configured to pre-calcine the co-precipitate and a lithium compound to form a precursor cathode active material. The apparatus may include a grinder or a milling machine configured to grind or mill the precursor cathode active material. The apparatus may include a calcination vessel configured to calcine the milled precursor cathode active material into a cathode active material. The apparatus may include one or more filters configured to separate solids from liquids. According to a fourth aspect of the present disclosure, there is provided a system for recovering material from a source material comprising one or more target metals, the system comprising: a first tank configured to leach one or more target metals from a source material at a temperature of 85°C or less and resulting in a pregnant leach solution containing the one or more target metals at a pH of between 0 and 2.3; a second tank in fluid communication with the first tank and configured to precipitate one or more intermediary metals or materials from solution; a third tank in fluid communication with the second tank and configured to remove any copper from solution via a copper cementation reaction; a fourth tank in fluid communication with the third tank and configured to selectively remove one or more target metals from solution via solvent extraction into separate streams; a fifth tank in fluid communication with the fourth tank and configured to precipitate nickel from solution. The system may be a material recovery plant. The system may be a recycling plant. The system may be a battery material recovery plant. The system may be a battery recycling plant. As such, the system is configured to conduct the various steps of the method according to the first aspect of the present disclosure. It will be appreciated that the various aspects of the present disclosure each relate to the same inventive concept and therefore any features described in respect of one aspect are equally applicable to any other aspect and may be combined in any combination. All such combinations are expressly considered and disclosed. In the first tank, one or more target metals, such as manganese, cobalt, nickel, and lithium are leached from a source material at a pH of between 0 and 2.3 and at a temperature of 85°C or less. This generates a pregnant leach solution, which may be passed to a second tank. The pregnant leach solution may be filtered to remove solids, such as graphite, which may be recovered. In the second tank, one or more intermediary metals, such as iron, copper, or aluminium, may be precipitated from solution by increasing the pH of the pregnant leach solution. The leach solution may then be passed to a third tank in which any copper may be removed from solution via a cementation reaction, which includes the addition of a metal which displaces copper from solution and is then oxidised to itself precipitate out of solution. The copper-depleted solution may then be passed to a fourth tank in which one or more target materials, preferably cobalt and manganese, are selectively removed by solvent extraction as is known in the art. Finally, a solution which has been depleted of cobalt, manganese, and nickel may be passed to a fifth tank in which nickel may be precipitated, preferably as nickel hydroxide. The system may include a sixth tank in fluid communication with the fifth tank and configured to precipitate sodium sulphate from solution. This may be achieved by cooling in order to reduce the solubility of sodium sulphate causing it to crash out of solution. The system may include a seventh tank in fluid communication with the sixth tank and configured to precipitate lithium from solution. The system may include an eighth tank in fluid communication with one or more of the fourth, fifth and seventh tanks and configured to co-precipitate the one or more target metals to form a mixed metal hydroxide or carbonate precipitate. By co-precipitating target metals together, the precipitate is more uniformly and intimately mixed that would otherwise be possible. The system may include a filter configured to filter out any solids between any of the tanks. Since solids are produced in the different tanks, it is desirable to separate these from the liquid. The solids may be recovered from the filters as required. The system may include an agitator in one or more tanks to stir liquid within a respective tank. The third tank may include an air inlet for providing air to the solution. By contacting the solution with air, which contains oxygen, it is possible to oxidise the metal used to displace the copper in solution and cause such metal to itself precipitate from solution. The fourth tank may include a mixing tank and a settling tank configured to separate an organic phase from an aqueous phase. The fourth tank may include one or more recycle lines to recycle one or both of the organic phase and the aqueous phase from the settling tank back into the mixing tank. This is because solvent extraction generally requires multiple passes to extract a target metal. The first tank may be a leach tank according to the second aspect of the present disclosure. According to a fifth aspect of the present disclosure, there is provided the use of the method according to the first aspect, the leach tank according to the second aspect, the apparatus according to the third aspect, or the system according to the fourth aspect of the present disclosure to recover material from a source material containing one or more target metals, preferably one or more of manganese, cobalt, nickel, and lithium. The source material may be selected from one or more of black mass, lithium-containing batteries, battery factory waste, precursor battery materials, mixed hydroxide precipitates, and combinations thereof. According to a sixth aspect of the present disclosure, there is provided a lithium leach solution produced according to the method of the first aspect of the present disclosure. According to a seventh aspect of the present disclosure, there is provided a mixed metal precipitate, such as a mixed metal hydroxide precipitate, MHP, comprising nickel, manganese, and cobalt produced according to the method of the first aspect of the present disclosure. The mixed metal hydroxide precipitate preferably includes nickel, manganese, and cobalt in any battery-suitable ratio. By battery suitable, it is understood that this means any ratio of these elements which is usable as a cathode material in a battery, which may optimise battery performance to battery ready, for direct re-use in new batteries, and be suitable for any end user application. Having a mixed feedstock input feed, this optimisation can be tweaked for a multitude of different chemistries (including any Li-ion battery, NMC, LiFePO4, NCA, and solid state batteries) co-blended in the desired ratios, for desirable end user battery performance characteristics. For example, lithium nickel manganese cobalt (NMC) oxides are used as the cathode of lithium ion batteries. The relative ratio of the nickel, manganese and cobalt alters the properties of the cathode. Examples of common NMC ratios include NMC 111 (in which the three metals are in equal proportions), NMC 532, NMC 622, and NMC 811. An advantage of the present invention is that the nickel, manganese, and cobalt are formed into separate streams, which may be mixed together in any desired ratio depending on the desired chemistry of any cathode active material to be formed from the mixed precipitate. According to an eighth aspect of the present disclosure, there is provided a composition comprising the mixed metal precipitate according to the seventh aspect of the present disclosure and lithium hydroxide. The composition may be at least partially oxidised, such as by calcination. As mentioned, cathode materials for lithium ion batteries include lithium nickel manganese cobalt oxide with the general formula LiNixMnyCoi-x-yO2, wherein 0 <x <1, and 0 <y <1, and wherein x + y <1. A NMC 111 composition would mean that x and y were both 1 / 3, such that 1 - x - y = 1 / 3 and so the nickel manganese, and cobalt are in the same ratio. An NMC 811 composition would mean that x = 0.8, y = 0.1, and 1 — x - y = 0.1. According to a ninth aspect of the present disclosure, there is provided a cathode active material comprising the composition according to the eighth aspect of the present disclosure or produced by the method according to the first aspect of the present disclosure. According to a tenth aspect of the present disclosure, there is provided a graphite material comprising crystallites having a minimum feret diameter of 5 microns or greater, optionally wherein the graphite material is a hydrometallurgically recovered graphite. The method, apparatus, and system according to the present disclosure allow for the recovery of graphite from a source material. The conditions used in the present disclosure are benign to graphite and therefore allow for the recovery of graphite from a source material that is particularly suitable for re-use in a battery. 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 various steps in the method of the present disclosure; Figure 2 is a schematic flowsheet depicting various subsequent steps in the method of the present disclosure; Figure 3 is a schematic flowsheet depicting various further subsequent steps in the method of the present disclosure; Figure 4 is a schematic flowsheet depicting yet further various subsequent steps in the method of the present disclosure; Figure 5 depicts a leach tank according to an aspect of the present disclosure; Figure 6 depicts a precipitation tank as used in the system of the present disclosure; Figure 7 depicts a cementation tank as used in the system of the present disclosure; Figure 8 depicts a solvent extraction tank including a mixing tank and a settling tank; Figure 9 depicts a nickel hydroxide precipitation take as used in the system of the present disclosure; Figure 10 depicts a sodium sulphate precipitation tank as used in the system of the present disclosure; Figure 11 depicts a lithium precipitation tank as used in the system of the present disclosure; and Figure 12 depicts a co-precipitation tankas used in the system 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 first flowsheet depicting various steps in the method according to the present invention. In the method of the invention, a source material 1, which may be black mass, a blended mixed feedstock, or any other source material as described herein, is provided. Water 3 is combined the source material 1. The water is added in an amount calculated depending on the amount of course material as well as the desired solid loading. Acid 2, such as sulphuric acid, is also combined with the mixture of water 3 and source material 1 in order to begin leaching metals from the source material 1. 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 2 and hydrogen peroxide 5 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 2 and hydrogen peroxide 5 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 6 and any other remaining solids are filtered out of the solution. The graphite 6 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 8. If calcium hydroxide is used as a base, this will also precipitate out, likely as calcium fluoride. Following the filtration step 8, there is a copper cementation step 9. The copper cementation step 9 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 10 and the copper may be separated and recovered by electrowinning. This forms depleted pregnant leach solution 11, 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 2, the depleted pregnant leach solution 11 is then passed to a series of extraction steps 12, 13, 14 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 15 from which manganese sulphate 16 can be removed, which forms a stripped DEHPA / kerosene stream 17, which is recycled back in order to extract further amounts of manganese from the depleted pregnant leach solution 11. 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 13. 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 18 from which cobalt sulphate 19 can be removed, which forms a stripped Cyanex™ / kerosene stream 20. The stripped Cyanex™ / kerosene stream 20 is recycled back in order to extract further amounts of cobalt from the depleted pregnant leach solution 11. 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 14 is conducted by including a base to adjust the pH of the depleted pregnant leach solution 11 to cause the nickel to be precipitated. The precipitated nickel is filtered in a filtration step 21 to form a lithium leach solution 22. As shown in Figure 3, the lithium leach solution 22 is concentrated in concentration step 23. This can be achieved by, for example, reverse osmosis. Any demineralised water 24 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 22 is optional. Prior to the concentration step 23, there may be a sodium sulphate precipitation step 25. The concentrated lithium leach solution is passed to a sodium sulphate precipitation step 25 in which any remaining sodium sulphate is precipitated out by cooling the concentrated lithium leach solution. Although depicted as following the lithium concentration step 23, additionally or alternatively, there may be a sodium sulphate precipitation step 25 before the concentration step 23. The sodium sulphate is filtered out in filtration step 26. Following on from sodium sulphate precipitation and filtration, the remaining solution is passed to a lithium carbonate precipitation step 27 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 28. The lithium carbonate 28 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 28 to lithium hydroxide. A final depleted leach solution 29 now depleted of all target metals may be taken off for further processing. As shown in Figure 4, nickel hydroxide 30, manganese sulphate 16, and cobalt sulphate 19 are blended with water and co-precipitated in a co-precipitation step 31 by the addition of a carbonate precipitant 32 to form a cathode active material precursor precipitate 33. 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 34. The cathode active material precursor precipitate 33 may undergo milling. For example, dry or wet planetary ball milling, rolling ball milling, high shear milling, air jet milling, and / or impact milling The cathode active material precursor precipitate 33 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 33. The pre-calcination step 35 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 36. Following pre-calcination, the NMC oxides 36 are blended with lithium hydroxide in a blending step 37 to form a lithium hydroxide / NMC oxide green body 38. The green body 38 is then calcined in a calcination step 39 to form a final cathode active material 40. Figure 5 depicts a leach tank 41 in accordance with the present disclosure, also referred to as the first tank. The leach tank 41 includes an agitator 42 that is configured to stir liquid within the tank. The agitator 42 is connected to a shaft 43 which is connected to a motor 44 configured to rotate the shaft 43. A foam breaker 45 is connected to the shaft 43. As the motor 44 drives the shaft 43, the agitator 42 and the foam breaker 45 also rotate. The foam breaker 45 is positioned above a nominal fill level 46 such that any foam generated is physically broken by the foam breaker 45. The leach tank 41 also includes a recirculation loop 47 that is configured to withdraw liquid from the tank and spray the liquid back into the tank to further break the foam (shown by the dotted line). The recirculation loop 47 may also serve to mix the liquid. One or more sensors (not shown) are located at any point on or in the tank from which the sensors are able to measure parameters, such as pH, temperature, fill level, or metal concentration of the liquid. The leach tank 41 includes a jacket 48 which is configured to carry a conditioning fluid 49 which controls the temperature of liquid in the tank. The jacket may include an inlet 48’ and an outlet 48” for the conditioning fluid 49. The orientation of the inlet 48’ and the outlet 48” may be other than as depicted in the figure. The leach tank 41 also includes a number of inlets through which source material and chemicals may be added. The leach tank 41 also includes outlets for a pregnant leach solution (PLS1) to exit the leach tank 41 and an outlet for off-gases. Although there may be solids in the solution, for clarity reference is made to a solution rather than a slurry. A valve 50 is provided and is reversibly openable to either retain the liquid within the tank or to allow it to leave the tank and be passed to a further tank. A fluid transfer line 52 for conveying any solids and / or pregnant leach solution, PLS1, is provided. The fluid transfer line 52 may pass the solids and / or pregnant leach solution, PLS1, to a filter (not shown) for separation of the solids or insoluble residues, such as graphite, from liquid PLS1. Figure 6 depicts a second tank 53 which is a precipitation tank. The second tank 53 includes an inlet 54 through which filtered liquid from fluid transfer line 52 enters. The second tank 53 also includes one or more inlets 55 through which a base and an oxidizing agent, such as hydrogen peroxide, may be added in order to increase the pH of the liquid and to thereby precipitate intermediary metals such as iron and aluminium. Again, the second tank 53 includes one or more sensors (not shown) that measure at least one parameter of the liquid, such as pH or temperature, as well as an agitator 42 and a jacket 48. In the second tank intermediary metals such as iron, copper, and aluminium are precipitated from solution through a change in pH. The solution PLS2 (comprising manganese, copper, aluminium, iron, nickel, cobalt, lithium) is then passed via transfer line 56 to a third tank (not shown), optionally via a filter (not shown) to remove precipitated solids. Figure 7 depicts a third tank 57 which is a cementation tank. The third tank 57 includes an inlet 58 through which filtered liquid PLS2 from fluid transfer line 56 enters. The third tank 57 also includes an inlet 59 through which iron powder, or indeed any other suitable metal, may be added in order to displace copper from solution. The third tank 57 also includes an air inlet 60 through which air is pumped into the solution in order to oxidise iron ions, causing them to precipitate out of solution. The air inlet 60 is connected to a dip tube, the end of which is submerged in the liquid so as to bubble air through the liquid. In the third tank 57, copper is removed as a metallic precipitate and iron is also removed as a precipitate. The third tank 57 also includes various sensors as required. The solution PLS3 which is depleted in copper and iron is then passed via transfer line 62 to a fourth tank (not shown), optionally via a filter (not shown) to remove precipitated solids. PLS3 comprises nickel, cobalt, manganese, and lithium in solution. Figure 8 depicts a fourth tank 63 which is a solvent extraction tank. The fourth tank 63 includes a mixing tank 64 and a settling tank 65. The mixing tank 64 and the settling tank 65 may be formed from chemical and solvent resistant polymer such as polypropylene, or may have a glass liner. The mixing tank 64 includes an inlet 66 for organic extractant and an inlet 67 through which filtered liquid PLS3 from transfer line 62 enters. The mixing tank 64 includes one or more inlets for acid / base addition. The mixing tank 64 includes a fluid connection 69 with the settling tank 65. The settling tank 65 includes a baffle 70 configured to reduce turbulence. The settling tank 65 also includes an organic outlet 71 and an aqueous outlet 72. The mixing tank 65 includes an agitator, preferably a high shear agitator. The mixing tank 65 preferably is angular in order to maximise shear in mixing. In operation, the aqueous solution from the third tank PLS3, which contains nickel, cobalt, manganese, and lithium is passed into the mixing tank 65 where it is mixed with an organic solvent, as known in the art for solvent extraction. The mixed organic and aqueous phases pass into the settling tank 65 via fluid connection 69 in which the two phases separate over time to form a lower aqueous layer 73 and an upper organic layer 74. The organic layer 74 may be recycled back into the organic extractant inlet 66. The aqueous layer 73 is passed via transfer line 72 to a fifth tank 75. There may be a plurality of solvent extraction tanks as known in the art. Figure 9 depicts a fifth tank 75 which is a nickel hydroxide precipitation tank. The fifth tank 75 includes an inlet 76 through which the aqueous layer 73 enters. The fifth tank 75 also includes an inlet 77 for receiving a base, such as ammonium hydroxide, sodium hydroxide, lithium hydroxide, or mixtures thereof. In the fifth tank 75, base is added to precipitate nickel hydroxide out of solution. The tank 75 also includes a transfer line 78 through which solution is passed to a sixth tank 79 (not shown), optionally via a filter (not shown) to remove precipitated solids. Figure 10 depicts a sixth tank 79 which is a sodium sulphate precipitation tank. The sixth tank 79 includes an inlet 80 through which the solution (containing lithium and sodium)) from the fifth tank 75 enters the sixth tank 79. The sixth tank 79 is a jacketed tank, although this is optional, and the conditioning fluid 49 serves to cool the liquid within the tank 79 in order to crystallize out sodium sulphate since sodium sulphate is considerably less soluble in cool water. The water may be cooled to around 2 to around 4°C. The tank 79 also includes a transfer line 78 through which solution is passed to a seventh tank 82 (not shown), optionally via a filter (not shown) to remove precipitated solids. Figure 11 depicts a seventh tank 82 which is a lithium precipitation tank. The seventh tank 82 includes an inlet 83 through which solution (substantially only lithium sulphate solution) from the sixth tank 79 enters. The lithium sulphate solution is slightly alkaline, for example a pH of between 7 and 9. The seventh tank 82 includes an inlet 84 through which sodium or ammonium carbonate may be added to precipitate lithium as lithium carbonate. The tank 82 also includes a transfer line 85 through which solution is passed to an eighth tank 86 (not shown), optionally via a filter (not shown) to remove precipitated solids. There may be a concentration step, such as a reverse osmosis step, between the sixth and seventh tanks in order to remove water from the solution and thereby increase the lithium concentration. Figure 12 depicts an eighth tank 86 which is a co-precipitation tank. The eighth tank 86 includes inlets for nickel, cobalt, and manganese streams 87, 88, 89 and an inlet 90 for a carbonate precipitant. In use, the nickel, cobalt, and manganese streams are mixed in the desired ratio within the eighth tank 86 and then co-precipitated out to form a precursor cathode active material (P-CAM). The eighth tank 86 also includes an outlet through which the co-precipitate may be removed. The co-precipitate may be filtered, dried, milled and pre-calcined (furnace not shown). The pre-calcined mixture may be milled and mixed with the lithium carbonate precipitated in the seventh tank and / or with make-up lithium carbonate. The mixture may be calcined to form a cathode active material. This may be calcined in any suitable kiln, for example a rotary kiln. 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, oxidative reductive potential, 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 for a process of recovering valuable materials from a source material, in particular battery materials including nickel, cobalt, manganese, and lithium. The present invention allows for the recycling of mixed source materials offering greater flexibility that existing processes. In addition, the leaching of metals into solution is conducted in a way which reduces the outgassing of harmful gases, reducing contaminants, which makes best use of the chemicals used by avoiding decomposition, avoids the disadvantages of high-sodium processes which create large quantities of sodium sulphate. Further, this leaching of metals into solution in the present invention, avoids the disadvantages of high-sodium processes which create large quantities of sodium in the system which is difficult to remove throughout the process and poses a continuous risk to contamination of products. Moreover, the defossilisation of the world economy supply chains necessitates the expansion of mineral extractions in both scale and scope, making the marketplace for disposal of sodium and sodium sulphate ever more challenging. The method involves a sustainable reduced carbon footprint, with optimised steps for better than 99% recovery, with efficient impurities removal, efficient chemical (including water, acid, solvent) extraction, and recycling of by-products in waste streams for reuse. Aspect of the present disclosure are described in the following numbered clauses: 1. A method of recovering material from a source material 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, ill) 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 wherein 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, such as 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. 2. The method according to clause 1, wherein the one or more target metals include manganese, cobalt, and nickel. 3. The method according to clause 1 or clause 2, wherein the acid is sulphuric acid. 4. The method according to any of clauses 1 to 3, wherein the base is selected from one or more of sodium hydroxide, calcium hydroxide, magnesium hydroxide, nickel hydroxide, cobalt hydroxide, manganese hydroxide, lithium hydroxide, a mixed hydroxide precipitate, or a combination of any thereof. 5. The method of any preceding clause, wherein, in step f), the one or more target metals is one or more of manganese, cobalt, and nickel. 6. The method according to any preceding clause, wherein the method further includes concentrating the lithium leach solution to form a concentrated lithium leach solution. 7. The method according to clause 6, wherein the method further includes adding one or both of sodium carbonate and ammonium carbonate to the concentrated lithium leach solution. 8. The method according to any preceding clause, wherein the method further includes precipitating sodium sulphate from the concentrated lithium leach solution and / or the lithium leach solution. 9. The method according to clause 7 or clause 8 when dependent on clause 7, wherein the method further includes precipitating lithium carbonate from the concentrated lithium leach solution. 10. The method according to any preceding clause, wherein the source material includes one or more of: black mass, lithium-containing batteries, battery factory waste, precursor battery materials, and mixed hydroxide precipitates, optionally wherein the source material is a mixed source material. 11. The method according to any preceding clause, wherein, prior to step a), the method further includes contacting the source material with a basic aqueous solution of an alkali or alkali earth metal salt, preferably other than chlorides, preferably other than sodium. 12. The method according to clause 11, wherein the method further includes recovering the basic aqueous solution after contacting the basic aqueous solution with the source material. 13. The method according to clause 11 or clause 12, wherein the method further includes separating out any metallic foils or plastics from the basic aqueous solution. 14. The method according to any preceding clause, wherein water is added in step a) to provide a solid loading within a predetermined range. 15. The method according to any preceding clause, wherein, in step a), the method includes adding the acid in stages or at a steady rate which controls foaming and spontaneous exothermic processes. 16. The method according to any preceding clause, wherein the method further includes adding acid in an amount which is greater than stoichiometric. 17. The method according to any preceding clause, wherein, in step c), the reducing agent, preferably peroxide, is added in an amount which is greater than stoichiometric. 18. The method according to any preceding clause, wherein, in step c), the temperature of the solution is 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. 19. The method according to any preceding clause, wherein the method includes stirring at any step. 20. The method according to any preceding clause, wherein the oxidizing agent in step d) is, oxygen, air, or peroxide, preferably oxygen or air. 21. The method according to any preceding clause when dependent on clause 4, wherein one or more of the lithium hydroxide, manganese hydroxide, cobalt hydroxide, and nickel hydroxide is a recycle stream at least partially obtained from the depleted leach solution. 22. The method according to any preceding clause, wherein the copper cementation step includes adding a metal having a more negative standard electrode potential than copper, such as iron, and air to precipitate copper from solution. 23. The method of any preceding clause, wherein the method further includes adding zinc to the depleted leach solution after step e) in order to precipitate any cadmium from solution. 24. The method of any preceding clause, wherein one, two, or all of manganese, cobalt and nickel are recovered from the depleted leach solution via solvent extraction. 25. The method according to clause 24, wherein the pH of the solution is adjusted using 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. 26. The method according to clause 24 or 25, wherein the pH is selected such that greater than 50% of a target metal is extracted. 27. The method according to any preceding clause, wherein nickel is precipitated from the pregnant leach solution using one, two or all of ammonium hydroxide, sodium hydroxide, lithium hydroxide, and mixtures thereof. 28. The method according to any preceding clause, wherein the pH of the depleted leach solution is 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. 29. The method according to any preceding clause, wherein the lithium leach solution is concentrated to increase the lithium concentration and / or is cooled to precipitate any sodium sulphate. 30. The method according to any preceding clause, wherein the method further includes 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 (P-CAM) 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. 31. The method according to clause 30, wherein the method further includes converting the cathode active material precursor precipitate P-CAM into a cathode active material. 32. The method according to clause 31, wherein the method includes one or more calcining steps to convert the cathode active material precursor P-CAM precipitate into a cathode active material. 33. The method according to clause 32, wherein the method includes incorporating lithium, optionally in the form of lithium hydroxide, after a pre-calcination step. 34. The method according to any preceding clause, wherein the method includes one or more grinding or milling steps. 35. The method according to any preceding clause, wherein the method includes one or more filtration steps. 36. A leach tank for leaching a material from a source material comprising one or more target metals, the leach tank comprising: a tank defining a volume; an agitator configured to stir liquid within the tank; a foam breaker configured to break foam within the tank; a recirculation loop configured to transfer liquid from within the tank to spray down foam within the tank. 37. The leach tank according to clause 36, wherein the agitator and the foam breaker are attached to a common shaft. 38. The leach tank according to clause 36 or clause 37, wherein the tank includes one or more sensors configured to measure a parameter of liquid within the tank, optionally wherein the one or more sensors includes a pH sensor, a temperature sensor, or a fill level sensor. 39. The leach tank according to any of clauses 36 to 38, wherein the tank includes an offtake branch configured to withdraw samples of liquid for testing. 40. The leach tank according to any of clauses 36 to 39, wherein the tank is a jacketed tank. 41. The leach tank according to any of clauses 36 to 40, wherein the tank includes one or more inlets configured to provide one or more of a source material, acid, water, and a reducing agent into the volume. 42. The leach tank according to any of clauses 36 to 41, wherein the tank includes one or more outlets configured to discharge one or more of offgas and a pregnant leach solution. 43. The leach tank according to any of clauses 36 to 41, wherein the tank includes an acid-resistant lining, preferably a PTFE lining. 44. An apparatus for recovering material from a source material containing one or more target metals, including one or more vessels configured to perform the method of any of clauses 1 to 35 optionally wherein the apparatus includes the leach tank according to any of clauses 36 to 43, optionally wherein the apparatus includes a leaching vessel configured to leach one or more target metals from a source material using an acid and a reducing agent, a precipitation vessel configured to precipitate one or more intermediary materials or metals from solution, a further precipitation vessel configured to precipitate any copper from solution, and a solvent extraction system configured to selectively separate target metals into separate streams. 45. A system for recovering material from a source material comprising one or more target metals, the system comprising: a first tank configured to leach one or more target metals from a source material at a temperature of 85°C or less and resulting in a pregnant leach solution containing the one or more target metals at a pH of between 0 and 2.3; a second tank in fluid communication with the first tank and configured to precipitate one or more intermediary metals from solution; a third tank in fluid communication with the second tank and configured to remove any copper from solution via a copper cementation reaction; a fourth tank in fluid communication with the third tank and configured to selectively remove one or more target metals from solution via solvent extraction into separate streams; a fifth tank in fluid communication with the fourth tank and configured to precipitate nickel from solution. 46. The system according to clause 45, wherein the system further includes a sixth tank in fluid communication with the fifth tank and configured to precipitate sodium sulphate from solution. 47. The system according to clause 46, wherein the system further includes a seventh tank in fluid communication with the sixth tank and configured to precipitate lithium from solution. 48. The system according to clause 47, wherein the system further includes an eighth tank in fluid communication with one or more of the fourth, fifth, and seventh tanks and configured to co-precipitate the one or more target metals to form a mixed metal hydroxide or carbonate precipitate. 49. The system according to any of clauses 45 to 48, wherein the system further includes a filter configured to filter out any solids between any of tanks. 50. The system according to any of clauses 45 to 49, wherein the system further includes an agitator in one or more tanks to stir liquid within a respective tank. 51. The system according to any of clauses 45 to 50, wherein the third tank includes an air inlet for providing air to the solution. 52. The system according to any of clauses 45 to 51, wherein the fourth tank comprises a mixing tank and a settling tank configured to separate an organic phase from an aqueous phase. 53. The system according to any of clauses 45 to 52, wherein the first tank is the leach tank according to any of clauses 36 to 43. 55. Use of the method according to any of clauses 1 to 35, the leach tank according to any of clauses 36 to 43, the apparatus according to clause 44, or the system according to any of clauses 45 to 52 to recover material from a source material containing one or more target metals, preferably one or more of manganese, cobalt, nickel, and lithium. 56. The use according to clause 55, wherein the source material is selected from one or more of black mass, batteries, lithium-containing batteries, battery factory waste, precursor battery materials, mixed hydroxide precipitates, and combinations thereof. 57. A lithium leach solution produced according to the method of any of clauses 1 to 35. 58. A mixed metal precipitate, optionally a mixed metal hydroxide precipitate, comprising nickel, manganese, and cobalt produced according to the method of clause 30. 59. A composition comprising the mixed metal precipitate of clause 58 and lithium hydroxide, blended in the desired ratios for end user battery ready applications 60. A composition according to clause 59, wherein the composition is at least partially oxidized. 61. A cathode active material comprising the composition according to clause 59 or clause 60. 62. A cathode active material produced according to any method clauses, 1-35, wherein the cathode active material is expressed by the general formula LiNixMnyCoi.x.yO2, wherein 0 <x <1, and 0 <y <1, and wherein x + y <1. 63. A cathode active material of Clause 62, for an NMC 111 composition where x and y are both 1 / 3, such that 1 - x - y = 1 / 3 and so the nickel manganese, and cobalt are in the same ratio. 64. A cathode active material of Clause 62, for an NMC 811 composition where x = 0.8, y = 0.1, and 1 - x - y = 0.1. 65. A graphite material comprising crystallites having a minimum feret diameter of 5 microns or greater, optionally wherein the graphite material is a hydrometallurgically recovered graphite.

Claims

1. A method of recovering material from a source material 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, andiv) 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, andiv) the initial concentration of one or more target metals in the source material; and wherein 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, such as 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; andf) recovering one or more target metals from the depleted leach solution to provide a lithium leach solution.

2. The method according to claim 1, wherein the one or more target metals include manganese, cobalt, and nickel, and / or wherein the acid is sulphuric acid, and / or wherein the base is selected from one or more of sodium hydroxide, calcium hydroxide, magnesium hydroxide, nickel hydroxide, cobalt hydroxide, manganese hydroxide, lithium hydroxide, a mixed hydroxide precipitate, or a combination of any thereof, optionallywherein one or more of the lithium hydroxide, manganese hydroxide, cobalt hydroxide, and nickel hydroxide is a recycle stream at least partially obtained from the depleted leach solution, and / or wherein, in step f), the one or more target metals is one or more of manganese, cobalt, and nickel.

3. The method according to any preceding claim, wherein the method further includes concentrating the lithium leach solution to form a concentrated lithium leach solution, optionally wherein the method further includes adding one or both of sodium carbonate and ammonium carbonate to the concentrated lithium leach solution.

4. The method according to any preceding claim, wherein the method further includes precipitating sodium sulphate from the concentrated lithium leach solution and / or the lithium leach solution, optionally wherein the method further includes precipitating lithium carbonate from the concentrated lithium leach solution.

5. The method according to any preceding claim, wherein the source material includes one or more of: black mass, lithium-containing batteries, battery factory waste, precursor battery materials, and mixed hydroxide precipitates, optionally wherein the source material is a mixed source material.

6. The method according to any preceding claim, wherein, prior to step a), the method further includes contacting the source material with a basic aqueous solution of an alkali or alkali earth metal salt, preferably other than chlorides, preferably other than sodium, optionally wherein the method further includes recovering the basic aqueous solution after contacting the basic aqueous solution with the source material, optionally wherein the method further includes separating out any metallic foils or plastics from the basic aqueous solution.

7. The method according to any preceding claim, wherein water is added in step a) to provide a solid loading within a predetermined range, and / or wherein, in step a), the method includes adding the acid in stages or at a steady rate which controls foaming and spontaneous exothermic processes.

8. The method according to any preceding claim, wherein the method further includes adding acid in an amount which is greater than stoichiometric, and / or wherein, in step c), the reducing agent, preferably peroxide, is added in an amount which is greater than stoichiometric, and / or wherein, in step c), the temperature of the solution is 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 about60°C.

9. The method according to any preceding claim, wherein the oxidizing agent in step d) is, oxygen, air, or peroxide, preferably oxygen or air.

10. The method according to any preceding claim, wherein the copper cementation step includes adding a metal having a more negative standard electrode potential than copper, such as iron, and air to precipitate copper from solution.

11. The method of any preceding claim, wherein the method further includes adding zinc to the depleted leach solution after step e) in order to precipitate any cadmium from solution.

12. The method of any preceding claim, wherein one, two, or all of manganese, cobalt and nickel are recovered from the depleted leach solution via solvent extraction, optionally wherein the pH of the solution is adjusted using 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, optionally wherein the pH is selected such that greater than 50% of a target metal is extracted.

13. The method according to any preceding claim, wherein nickel is precipitated from the pregnant leach solution using one, two or all of ammonium hydroxide, sodium hydroxide, lithium hydroxide, and mixtures thereof, optionally wherein the pH of the depleted leach solution is 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.

14. The method according to any preceding claim, wherein the lithium leach solution is concentrated to increase the lithium concentration and / or is cooled to precipitate any sodium sulphate.

15. The method according to any preceding claim, wherein the method further includes 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 (P-CAM) 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, optionally wherein the method further includes converting the cathode active material precursor precipitate P-CAM into a cathode active material, optionally wherein the method includes one or more calcining steps to convert the cathode active material precursor P-CAM precipitate into a cathode active material, optionally wherein the method includes incorporating lithium, optionally in the form of lithium hydroxide, after a pre-calcination step.

16. A leach tank for leaching a material from a source material comprising one or more target metals, the leach tank comprising:a tank defining a volume;an agitator configured to stir liquid within the tank;a foam breaker configured to break foam within the tank;a recirculation loop configured to transfer liquid from within the tank to spray down foam within the tank.

17. The leach tank according to claim 16, wherein the agitator and the foam breaker are attached to a common shaft, and / or wherein the tank includes one or more sensors configured to measure a parameter of liquid within the tank, optionally wherein the one or more sensors includes a pH sensor, a temperature sensor, or a fill level sensor, and / or wherein the tank includes an offtake branch configured to withdraw samples of liquid for testing.

18. An apparatus for recovering material from a source material containing one or more target metals, including one or more vessels configured to perform the method of any of claims 1 to 15 optionally wherein the apparatus includes the leach tank according to any of claims 16 to 17, optionally wherein the apparatus includes a leaching vessel configured to leach one or more target metals from a source material using an acid and a reducing agent, a precipitation vessel configured to precipitate one or more intermediary materials or metals from solution, a further precipitation vessel configured to precipitate any copper from solution, and a solvent extraction system configured to selectively separate target metals into separate streams.

19. A system for recovering material from a source material comprising one or more target metals, the system comprising:a first tank configured to leach one or more target metals from a source material at a temperature of 85°C or less and resulting in a pregnant leach solution containing the one or more target metals at a pH of between 0 and 2.3;a second tank in fluid communication with the first tank and configured to precipitate one or more intermediary metals from solution;a third tank in fluid communication with the second tank and configured to remove any copper from solution via a copper cementation reaction;a fourth tank in fluid communication with the third tank and configured to selectively remove one or more target metals from solution via solvent extraction into separate streams;a fifth tank in fluid communication with the fourth tank and configured to precipitate nickel from solution.

20. The system according to claim 19, wherein the system further includes a sixth tank in fluid communication with the fifth tank and configured to precipitate sodium sulphate from solution, optionally wherein the system further includes a seventh tank in fluid communication with the sixth tank and configured to precipitate lithium from solution, optionally wherein the system further includes an eighth tank in fluid communication with one or more of the fourth, fifth, and seventh tanks and configured to co-precipitate the one or more target metals to form a mixed metal hydroxide or carbonate precipitate.

21. The system according to any of claims 19 to 20, wherein the third tank includes an air inlet for providing air to the solution.

22. The system according to any of claims 19 to 21, wherein the fourth tank comprises a mixing tank and a settling tank configured to separate an organic phase from an aqueous phase.

23. The system according to any of claims 19 to 22, wherein the first tank is the leach tank according to any of claims 16 to 17.

24. Use of the method according to any of claims 1 to 15, the leach tank according to any of claims 16 to 17, the apparatus according to claim 18, or the system according to any of claims 19 to 23 to recover material from a source material containing one or more target metals, preferably one or more of manganese, cobalt, nickel, and lithium, optionally wherein the source material is selected from one or more of black mass, batteries, lithium-containing batteries, battery factory waste, precursor battery materials, mixed hydroxide precipitates, and combinations thereof.

25. A lithium leach solution produced according to the method of any of claims 1 to 15.

26. A mixed metal precipitate, optionally a mixed metal hydroxide precipitate, comprising nickel, manganese, and cobalt produced according to the method of any of claims 1 to 15 .

27. A composition comprising the mixed metal precipitate of claim 26 and lithium hydroxide, blended in the desired ratios for end user battery ready applications, optionally wherein the composition is at least partially oxidized.

28. A cathode active material comprising the composition according to claim 27.

29. A cathode active material produced according to any of method claims 1 to 15, wherein the cathode active material is expressed by the general formula LiNixMnyCoi-x-yO2, wherein 0 <x <1, and 0 <y <1, and wherein x + y <1, optionally wherein for an NMC 111 composition where x and y are both 1 / 3, such that 1 - x - y = 1 / 3 and so thenickel manganese, and cobalt are in the same ratio or for an NMC 811 composition wherex = 0.8, y = 0.1, and 1-x-y = 0.1.

30. A graphite material comprising crystallites having a minimum feret diameter of 5 microns or greater, optionally wherein the graphite material is a hydrometallurgically 5 recovered graphite.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:20 11 2447CLAIMS:

1. A method of recovering material from a source material 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, andiv) the initial concentration of one or more target metalsto 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, andiv) the initial concentration of one or more target metals in the source material; and wherein 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 5 to 5.3, wherein the base is selected from one or more of calcium hydroxide, magnesium hydroxide, nickel hydroxide, cobalt hydroxide, manganese hydroxide, lithium hydroxide, or a combination of any thereof, and providing an oxidizing agent to precipitate any intermediary metals, such as 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; andf) recovering one or more target metals from the depleted leach solution to provide a lithium leach solution.

2. The method according to claim 1, wherein the one or more target metals include manganese, cobalt, and nickel, and / or wherein the acid is sulphuric acid, and / or wherein one or more of the lithium hydroxide, manganese hydroxide, cobalt hydroxide, and nickelhydroxide is a recycle stream at least partially obtained from the depleted leach solution, and / or wherein, in step f), the one or more target metals is one or more of manganese, cobalt, and nickel.

3. The method according to any preceding claim, wherein the method further includes 5 concentrating the lithium leach solution to form a concentrated lithium leach solution, optionally wherein the method further includes adding one or both of sodium carbonate and ammonium carbonate to the concentrated lithium leach solution.

4. The method according to any preceding claim, wherein the method further includes precipitating sodium sulphate from the concentrated lithium leach solution and / or the 10 lithium leach solution, optionally wherein the method further includes precipitating lithium carbonate from the concentrated lithium leach solution.1525305. The method according to any preceding claim, wherein the source material includes one or more of: black mass, lithium-containing batteries, battery factory waste, precursor battery materials, and mixed hydroxide precipitates, optionally wherein the source material is a mixed source material.

6. The method according to any preceding claim, wherein, prior to step a), the method further includes contacting the source material with a basic aqueous solution of an alkali or alkali earth metal salt, preferably other than chlorides, preferably other than sodium, optionally wherein the method further includes recovering the basic aqueous solution after contacting the basic aqueous solution with the source material, optionally wherein the method further includes separating out any metallic foils or plastics from the basic aqueous solution.

7. The method according to any preceding claim, wherein water is added in step a) to provide a solid loading within a predetermined range, and / or wherein, in step a), the method includes adding the acid in stages or at a steady rate which controls foaming and spontaneous exothermic processes.

8. The method according to any preceding claim, wherein the method further includes adding acid in an amount which is greater than stoichiometric, and / or wherein, in step c), the reducing agent, preferably peroxide, is added in an amount which is greater than stoichiometric, and / or wherein, in step c), the temperature of the solution is from 40°C to 85°C, from 50°C to 70°C, from 55°C to 65°C, or 60°C.

9. The method according to any preceding claim, wherein the oxidizing agent in step d) is, oxygen, air, or peroxide, preferably oxygen or air.1015253010. The method according to any preceding claim, wherein the copper cementation step includes adding a metal having a more negative standard electrode potential than copper, such as iron, and air to precipitate copper from solution.

11. The method of any preceding claim, wherein the method further includes adding zinc to the depleted leach solution after step e) in order to precipitate any cadmium from solution.

12. The method of any preceding claim, wherein one, two, or all of manganese, cobalt and nickel are recovered from the depleted leach solution via solvent extraction, optionally wherein the pH of the solution is adjusted using 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, optionally wherein the pH is selected such that greater than 50% of a target metal is extracted.

13. The method according to any preceding claim, wherein nickel is precipitated from the pregnant leach solution using one, two or all of ammonium hydroxide, sodium hydroxide, lithium hydroxide, and mixtures thereof, optionally wherein the pH of the depleted leach solution is increased to 7 to 11, to 8 to 10, to 8.5 to 9.5, or to 9 to 9.5 in order to precipitate nickel.

14. The method according to any preceding claim, wherein the lithium leach solution is concentrated to increase the lithium concentration and / or is cooled to precipitate any sodium sulphate.

15. The method according to any preceding claim, wherein the method further includes 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 (P-CAM) 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, optionally wherein the method further includes converting the cathode active material precursor precipitate P-CAM into a cathode active material, optionally wherein the method includes one or more calcining steps to convert the cathode active material precursor P-CAM precipitate into a cathode active material, optionally wherein the method includes incorporating lithium, optionally in the form of lithium hydroxide, after a pre-calcination step.5016. Use of the method according to any of claims 1 to 15, to recover material from a source material containing one or more target metals, preferably one or more of manganese, cobalt, nickel, and lithium, optionally wherein the source material is selected5 from one or more of black mass, batteries, lithium-containing batteries, battery factory waste, precursor battery materials, mixed hydroxide precipitates, and combinations thereof.20 11 24