WO2025010462A1 - Pyrometallurgical recycling of end-of-life batteries - Google Patents

Abstract

According to the present invention there is provided a method for the extraction of one or more valuable base metals from end-of-life battery waste, the method comprising the steps of: obtaining the end-of-life battery waste having a content of the one or more valuable metals; subjecting the black mass to a pyrometallurgical furnace defined by a turbulent bath comprising: one or more sulfidising agent/s; one or more flux/es; one or more fuel/s; thereby to provide for an oxygen partial pressure of between about 10^-13 and about 10^-4 atm; forming a base metal matte and a slag, the slag comprising less than about 5 wt.% base metal/s; separating the matte and the slag; and further refining the base metal matte, thereby to obtain the one or more valuable base metal/s.

Description

PYROMETALLURGICAL RECYCLING OF END-OF-LIFE BATTERIES

Related Applications

[0001] The present application claims convention priority from Australian Provisional Patent Applications 2023902216, dated 11 July 2023 and 2023903803, dated 27 November 2023. The content of AU’216 and AU’803 is incorporated herein by reference in its entirety.

Field of the Invention

[0002] The present invention relates to a method for treating end-of-life batteries, obtaining a high recovery of one or more valuable base metals (e.g., Ni, Co, Cu, Zn, Pb, Mn etc.) and associated base metals (e.g., Au, Ag, Pt, etc.) into a molten matte phase. The matte phase can then be processed in a base metal refinery. The residual slag can be sold or safely disposed of.

[0003] More particularly, the present invention relates to a method of extracting valuable battery materials and/or valuable metals, such as cobalt, copper, nickel, lithium, etc., from end-of-life batteries, preferably lithium-ion batteries.

[0004] More particularly still, the invention describes a method for smelting end-of- life lithium-ion batteries, wherein the process comprises feeding a mixture of these materials plus a sulfidising agent, fluxes, and fuel into a furnace, injecting air and/or oxygen into the molten charge to achieve an oxygen partial pressure between 10'⁶ atm and 10'¹¹ atm such that a base metal matte is formed to which the majority of the valuable metals report. Also formed is a slag containing less than 5 wt.% of the base metals. The molten slag is subsequently sold (as aggregate), processed to recover non-base metals e.g., lithium) or discarded. The molten base metal matte may be further processed in a base metal refinery or smelted via known techniques.

[0005] Although the present invention will be described hereinafter with reference to its preferred embodiment, it will be appreciated by those skilled in the art that the spirit and scope of the invention may be embodied in many other forms.

Background of the Invention

[0006] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0007] Valuable metals are mined from their constituent ores at an exponentially- increasing rate. With the overall supply being strictly finite, some metals are already under supply and sustainability pressure. Without increased adoption of recycling practices, the global supply of certain metals will inevitably extinguish long before consumer demand subsides. Examples of such metals include nickel, copper, manganese, cobalt and lithium.

[0008] Cobalt’s value resides principally in its utility across industries such as alloys, batteries, catalysis, pigments, radioisotopes, electroplating and porcelain enamels.

[0009] Nickel is used across many industrial and consumer products including stainless steel, alnico magnets, coinage, rechargeable batteries (e.g., nickel-iron), electric guitar strings, microphone capsules, plating on plumbing fixtures and special alloys such as permalloy, elinvar, and invar. It is widely used in many other alloys, including nickel brasses and bronzes and alloys with copper, chromium, aluminium, lead, cobalt, silver, and gold.

[0010] Manganese is applied industrially across steelmaking, alloying, batteries, resistors, minting and ceramic colourings.

[0011] At an industrial level, lithium is assuming ever-increasing popularity given its many uses: ceramics, glasses, batteries, electronics, lubricating greases, metallurgy, pyrotechnics, air purification, optics, polymer chemistry, military applications and medicine - to name but a few. One of the principal uses of lithium is in batteries - and demand will only continue to grow as (amongst other emerging technologies) all-electric vehicles take to the roads over the next few years. Lithium is especially amenable to use in batteries owing to its high electrode potential (the highest of all metals) and its low atomic mass, which leads to high charge-to-weight and power-to-weight ratios. Lithium batteries are preferred over other batteries due to their relatively high charge density (long life), but presently suffer from a relatively high cost per unit. Depending on the design and chemical compounds used, lithium cells can produce voltages from 1.5 V (comparable to a zinc-carbon or alkaline battery) to about 3.7 V.

[0012] With society’s ever- increasing environmental consciousness and demand for battery power as an alternative to fossil fuels comes the inevitability of new waste streams for spent batteries. However, a further inevitability of this mindset working in unison with such waste streams has been a surge in recycling technologies in which, for instance, at least some of the valuable metals contained within spent batteries are recovered and recycled for future use.

[0013] It is estimated that by 2030, around 1.2 million tons of lithium-ion batteries will have reached end-of-life. This comprises an estimated potential recovery of 125,000 tons of lithium, 35,000 tons of cobalt and 86,000 tons of nickel, which could be recovered for use in new battery production. Such numbers must be considered against the fact that global supply of such elements is strictly finite and absent effective recycling practices, the technology span of lithium-ion batteries may be limited by supply rather than by the emergence of new and better battery technologies. [0014] End-of-life battery waste” is the industry term used to describe a type of e- waste comprising crushed and shredded end-of-life battery cells. It contains a mixture of valuable metals including lithium, manganese, cobalt, nickel along with graphite and other casing or electrode materials. Initially, waste batteries are collected, sorted, discharged and disassembled. This is followed by mechanical crushing, drying, sorting sieving and pyrolysis to 700 °C to remove any remaining electrolyte and potentially hazardous to health fluorine-containing components. The resulting material is what is referred to in the battery recycling industry as “treated end-of-life battery waste”.

[0015] In traditional battery recycling, metals are typically extracted in the last step or after significant processing. Examples include hydrometallurgy and pyrometallurgy. Hydrometallurgy (see, e.g., Wang, H., Friedrich, B. Development of a Highly Efficient Hydrometallurgical Recycling Process for Automotive Li-Ion Batteries. J. Sustain. Metall. 1, 168-178, 2015) refers to the extraction of metal by preparing an aqueous solution of a salt of the metal and recovering the metal from the solution. The operations usually involved are leaching, or dissolution of the metal or metal compound in water, commonly with additional agents; separation of the waste and purification of the leach solution; and the precipitation of the metal or one of its pure compounds from the leach solution by chemical or electrolytic means. Common leaching agents include sulfuric acid, hydrochloric acid and hydrogen peroxide, etc. Multiple steps are required, and significant wastewater is produced.

[0016] Pyrometallurgy (see, e.g., Assefi, et al., Pyrometallurgical recycling of Li-ion, Ni-Cd and Ni-MH batteries: A minireview, Current Opinion in Green and Sustainable Chemistry, 24, 26-31, 2020) refers to the extraction and purification of metals by processes involving the application of heat. The most important operations are roasting, smelting, and refining. Such processes are extremely energy-intensive, consume many environmentally harmful chemicals and result in the generation of hazardous gases.

[0017] Recovery of valuable metals from end-of-life battery waste by traditional hydrometallurgical or pyrometallurgical means thereby comes at a considerable environmental and consequently financial cost. Unsurprisingly, several alternative technologies have emerged in recent years.

[0018] US 11,661,638, to Umicore, describes a process and a slag suitable for the recovery of Ni and Co from Li-ion batteries or their waste. The slag composition is defined according to: 10%<MnO<40%; (CaO+1.5*Li2O)/A12O3>0.3; CaO+0.8* MnO+0.8*Li₂O<60%; (CaO+2*Li₂O+0.4*MnO)/SiO2>2.0; Li₂>l%; and A12O3+SiO2+CaO+Li2O+MnO+FeO+MgO>85%. This composition is particularly adapted to limit or avoid the corrosion of furnaces lined with magnesia-bearing refractory bricks.

[0019] US 2020/0263276, to Sumitomo Metal Mining Co., Ltd., describes method for treating lithium ion battery waste using a converter furnace in a copper smelting process, wherein, prior to a treatment for charging a copper matte produced in a flash smelter in a copper smelting process into a converter furnace and blowing oxygen into the converter furnace to produce crude copper, the lithium ion battery waste is introduced into the converter furnace or a ladle that is used for the charging of the copper matte into the converter furnace and then the lithium ion battery waste is burned with residual heat in the converter furnace or the ladle.

[0020] WO 2022/045973, to Green Li-Ion Pte. Ltd., describes a method of treating a leaching solution derived from a black mass (essentially synonymous with end-of-life battery waste) from spent lithium-ion batteries comprising setting pH of the leaching solution to about pH 1.2 to 2.5, adding iron powder to induce copper cementation, adding lime after copper cementation, and after adding lime, transiting pH of the leaching solution to about pH 6 to extract calcium fluoride, titanium hydroxide, aluminium hydroxide, iron hydroxide, and iron phosphate. Also disclosed is a black mass recycling system comprising an impurity removal reactor configured to receive a sodium hydroxide feed, an iron powder feed, and a lime feed.

[0021] US 9,484,606, to Hulico LLC, describes a method of recycling and refurbishing battery electrode materials. For example, one disclosed embodiment provides a method comprising obtaining a quantity of spent electrode material, reacting the spent electrode material with an aqueous lithium solution in an autoclave while heating the spent electrode material and the aqueous lithium solution to form a hydrothermally reacted spent electrode material, removing the hydrothermally reacted spent electrode material from the aqueous lithium solution, and sintering the hydrothermally reacted spent material to form a recycled electrode material.

[0022] US 9,312,581, to Commissariat a L’energie Atomique Et Aux Energies Alternatives, relates to a method for recycling lithium batteries and more particularly batteries of the Li-ion type and the electrodes of such batteries. The method comprises the following steps: a) grinding of said electrodes and/or of said batteries, b) dissolving the organic and/or polymeric components of said electrodes and/or of said batteries in an organic solvent, c) separating the undissolved metals present in the suspension obtained in step b), d) filtering the suspension obtained in step c) through a filter press, e) recovering the solid mass retained on the filter press in step d), and suspending this solid mass in water, f) recovering the material that sedimented or coagulated in step e), resuspending this sedimented material in water and adjusting the pH of the suspension obtained to a pH below 5, preferably below 4, g) filtering the suspension obtained in step f) on a filter press, and h) separating, on the one hand, the iron by precipitation of iron phosphates, and on the other hand the lithium by precipitation of a lithium salt.

[0023] Conventional recycling plants appear focused on particular metals, such as cobalt and often ignore other valuable metals, such as manganese and nickel. Generally, these plants are not equipped to handle different types of lithium-ion batteries and the impurities introduced.

[0024] Existing pyrometallurgical methods of treating lithium-ion batteries each suffer to some degree from the challenges associated with operating a bath of molten metal in the furnace. This molten metal has a high liquidus temperature, requiring high operating temperatures. These high operating temperatures result in highly corrosive and aggressive slags, leading to short furnace campaigns and challenges in monitoring the furnace operation. The molten metal also freezes easily (/'.<?., it has a high heat conductivity), leading to challenges in keeping the furnace bath molten, managing accretions in launders during tapping, and reducing the number of downstream processing options. In addition, the base metal alloys cannot be processed in existing base metal refineries due to a lack of sulfur in the alloy phase.

[0025] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0026] It is an object of a particularly preferred form of the present invention to provide for an extraction process which can recycle valuable metals and/or materials from end-of-life battery waste. Most preferably, the valuable metals are selected from the group consisting of cobalt, nickel, manganese and lithium.

[0027] It is an object of certain preferred forms of the present invention to provide for a smelting process that may simultaneously achieve one or more of the following outcomes: Produce a base metal rich material with a melting point less than about 1350 °C; produce a glassy slag material containing Si, Al, Mn and other oxides, with a low concentration of base metals; produce a clean off gas; decrease the operating temperature of the furnace; decrease the corrosivity of the furnace slag; decrease the base metal alloy liquidus temperature (freezing point); and enable the base metal product to be processed in a base metal refinery.

[0028] Although the invention will be described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Definitions

[0029] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention pertains.

[0030] End-of-life battery materials” refers to, essentially, whole or crushed end-of- life battery waste. For the avoidance of doubt, the end-of-life battery waste subject of the present invention is “raw” end-of-life battery waste. It was not pre-treated (for example, by pyrolysis, to remove the battery electrolytes, or sodium hydroxide leaching and sonication to remove aluminium). The economic potential of a recycling method that is efficacious despite avoiding expensive pre-treatment step/s is clear. [0031] Valuable base metals” refers to any metal that may be present in the end-of- life battery waste, including, not limited to, one or more of Li, Au, Ag, Al, Ca, Cr, Co, Cu, Fe, Ga, K, Mg, Mn, Na, Ni, and V. “Valuable base metals” may also extend to oxides of such metals, for example, SiCh, CaO, AI2O3, Li2O, MnO, MgO, etc.

[0032] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[0033] As used herein, the phrase “consisting of’ excludes any element, step, or ingredient not specified in the claim. When the phrase “consists of’ (or variations thereof) appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. As used herein, the phrase “consisting essentially of’ limits the scope of a claim to the specified elements or method steps, plus those that do not materially affect the basis and novel characteristic(s) of the claimed subject matter. [0034] With respect to the terms “comprising”, “consisting of’, and “consisting essentially of’, where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments not otherwise explicitly recited, any instance of “comprising” may be replaced by “consisting of’ or, alternatively, by “consisting essentially of’.

[0035] Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term “about”, having regard to normal tolerances in the art. The examples are not intended to limit the scope of the invention. In what follows, or where otherwise indicated, “%” will mean “weight %”, “ratio” will mean “weight ratio” and “parts” will mean “weight parts”.

[0036] Units and measures are provided according to the metric system, with the exception being pressure, which is quoted in atmospheres (atm).

[0037] The term “substantially” as used herein shall mean comprising more than 50% by weight, where relevant, unless otherwise indicated.

[0038] The term “about” should be construed by the skilled addressee having regard to normal tolerances in the relevant art.

[0039] The recitation of a numerical range using endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0040] The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0041] It must also be noted that, as used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0042] The prior art referred to herein is fully incorporated herein by reference unless specifically disclaimed.

[0043] Although example embodiments of the disclosed technology are explained in detail herein, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the disclosed technology be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosed technology is capable of other embodiments and of being practiced or carried out in various ways.

[0044] This specification is prepared having regard to the principles of general application. As such, where the specification discloses a principle of general application, the claims may be drafted in correspondingly general terms (Biogen v Medeva [1997] RPC 1 at 48). A “principle of general application” is a general principle that can be practically applied in making a class of products, or in working a process, including where the claims define the products or process(es) in terms of the result to be achieved. [0045] A feature in the claims stated in general terms will represent a principle of general application, where it is reasonable to expect (reasonable to predict) that the claimed invention will work with anything that falls within the general term. Such a feature defined in general terms may be a major part of the claim, or it may be a simple descriptive word. In either case, a feature in the claims expressed in general terms will be sufficiently enabled if the disclosure enables at least one form of, or one application of, a general principle in respect of the feature, and the person skilled in the art would reasonably expect the invention to work with anything that falls within the general term. (Kirin- Amgen Inc. v Hoechst Marion Roussel Ltd [2005] RPC 9 at [112]). [0046] Where the claims are more broadly drafted they may be considered enabled if, prima facie: a) the disclosure teaches a principle that the person skilled in the art would need to follow in order to achieve each and every embodiment falling within a claim; and b) the specification discloses at least one application of the principle and provides sufficient information for the person skilled in the art to perform alternative applications of the principle in a way that, while not explicitly disclosed, would nevertheless be obvious to the person skilled in the art (T484/92).

[0047] Finally, unless indicated otherwise, the term “purity” is referenced on a molar basis.

Brief Description of the Drawings

[0048] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings, in which:

[0049] Figure 7 is a flowchart of a preferred embodiment of the present invention, which defines a method for the extraction of one or more valuable base metal/s from end- of-life battery materials, the method comprising the steps of: obtaining the mass end-of- life battery materials (“feed preparation”) having a content of the one or more valuable base metal/s; subjecting the black mass to a pyrometallurgical furnace (e.g., an ISASMELT™ furnace) defined by a molten turbulent bath comprising one or more sulfidising agent/s; one or more flux/es; one or more fuel/s; thereby to provide for an oxygen partial pressure of between about 10'¹³ and about 10'⁴ atm; subjecting the off-gas to a gas scrubber to provide for a clean off-gas and an effluent; forming a base metal matte (z.e., molten metal sulfide phase) and a slag (z.e., molten metal oxide phase), the slag comprising less than about 5 wt.% base metal/s with the balance reporting to the matte; and separating the matte from the slag in a settling furnace.

Summary of the Invention

[0050] The present invention relates generally to a method for the pyrometallurgical processing of end-of-life battery materials, preferably lithium-ion batteries, mixed with a low temperature (<900 °C) sulfidising agent, which may at least partially overcome some of the known disadvantages of past methods for high temperature spent battery treatment. Such a processing method is presented in Figure 1. [0051] The present invention utilises a “sulfur deficient matte”. The advantage of the sulfur deficient matte is that an operator can adjust the liquidus temperature of the matte phase depending on the amount of sulfur in the melt. This means that if the slag has a high liquidus temperature, the operator can run with a sulfur deficient matte to prevent a superheated matte from forming. A normal matte is a molten sulfide (NiS-C S-CoS-FeS, etc.), while a sulfur deficient matte is between a metal and a normal matte (Ni-NiS-Cu- CmS-Fc-FcS-Co-CoS, etc.).

[0052] According to a first aspect of the present invention there is provided a method for the extraction of one or more valuable base metal/s from end-of-life battery materials, the method comprising the steps of:

[0053] a) obtaining the end-of-life battery materials having a content of the one or more valuable base metal/s;

[0054] b) subjecting the end-of-life battery materials to a pyrometallurgical furnace defined by a molten turbulent bath comprising:

[0055] one or more low temperature (<950 °C) sulfidising agent/s;

[0056] one or more flux/es;

[0057] one or more fuel/s and/or coolant/s;

[0058] thereby to provide for an oxygen partial pressure of between about 10'¹³ and about 10'⁴ atm;

[0059] c) forming a base metal matte and a slag, the slag comprising less than about 5 wt.% base metal/s with the balance reporting to the matte; and

[0060] d) separating the matte from the slag.

[0061] In an embodiment, the inventive extraction method is complete in about < 1 minutes. At these high temperatures, the reaction kinetics are very fast. Those of skill in the art will appreciate that furnaces are typically sized based on the feed and product handling constraints rather than residence time in the vessel.

[0062] In an embodiment, the method comprises the further step of:

[0063] e) further refining the base metal matte, thereby separating and purifying one or more valuable base metal/s.

[0064] In an embodiment, the slag contains >0.1 wt.% sulfur. In contrast, the slag formed in the method of US 11,661,638 (discussed above) contains no sulfur.

[0065] In an embodiment, the one or more low temperature sulfidising agent/s comprise sulfur, gypsum, metal sulfides and/or metal sulfates such as sodium, calcium, magnesium, copper, iron(II), iron (III), hydrogen and lead.

[0066] In an embodiment, the one or more sulfidising agent/s comprise gypsum.

[0067] In an embodiment, the gypsum comprises CaSO4.2H2O.

[0068] In an embodiment, the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is between about 1 and about 28 wt.%.

[0069] In an embodiment, the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 wt.%.

[0070] In an embodiment, the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is between about 1 to 22, 2 to 21, 3 to 20, 4 to 19, 5 to 18, 6 to 17, 7 to 16, 7.5 to 15, 8 to 14, 8.5 to 13, 9 to 12, 9.5 to 11, or about 10 wt.%. In a preferred embodiment, the amount of sulfur in the base metal matte is about 10 wt.%.

[0071] In an embodiment, the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is between about 5 and about 15 wt.%.

[0072] In an embodiment, the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is about 10 wt.%.

[0073] In another embodiment, a molar excess of sulfur is provided between about 0.1:1 and 25:1, preferably about 0.5:1, with the excess sulfur being relative to the stoichiometric Me® + S(i) MeS(i) reaction, where Me is the metal/s reporting to the matte phase.

[0074] In various embodiments, the molar excess of elemental sulfur is about 0.11:1, 1.1:1, 2: 1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21: 1, 22:1, 23:1, 24:1, or 25:1.

[0075] In an embodiment, the oxygen partial pressure within the pyrometallurgical furnace is between about 10'^{11 5} and about 10'⁶ atm.

[0076] In an embodiment, the oxygen partial pressure within the pyrometallurgical furnace is between about 10'¹⁰⁵ and about 10'⁷ atm.

[0077] In an embodiment, the oxygen partial pressure within the pyrometallurgical furnace is about 10’¹³, IO'¹²⁵, IO’¹², 10'^{11 5}, W¹¹, IO'¹⁰⁵, IO’¹⁰, IO'^{9 5}, IO’⁹, 10'^{8 5}, 10’⁸, W ⁷-⁵, IO’⁷, IO’⁶⁵, IO’⁶, IO’^{5 5}, 10’⁵, IO’⁴⁵, or IO’⁴ atm.

[0078] In an embodiment, the oxygen partial pressure within the pyrometallurgical furnace is between about 10'¹²to 10'⁵, 10^-11 to 10'⁶, 10'¹⁰⁵ to 10'⁷, 10'¹⁰ to 10'^{7 5}, 1 O'^{9 5} to IO'⁸, or 10'⁹ to 10'^{8 5} atm.

[0079] In an embodiment, the oxygen partial pressure within the pyrometallurgical furnace is about 10'⁹ atm.

[0080] In an embodiment, the further refining comprises converting the metal sulfides/s present in the base metal matte to their respective elemental metal or chemical products (e.g., nickel sulfate, nickel hydroxide) via conventional techniques.

[0081] In an embodiment, the pyrometallurgical furnace is further defined by a temperature greater than about 1000 °C.

[0082] In an embodiment, the pyrometallurgical furnace is further defined by a temperature between about 1000 and about 1800 °C.

[0083] In an embodiment, the pyrometallurgical furnace is further defined by a temperature greater than about 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650,1700, 1750 or 1800 °C.

[0084] In an embodiment, the pyrometallurgical furnace is further defined by a temperature between about 1000 to 1800, 1100 to 1750, 1200 to 1700, 1250 to 1650, 1300 to 1600, 1350 to 1550, 1400 to 1500 or about 1450 °C.

[0085] In an embodiment, step b), step c) and step d) are conducted in a single vessel.

[0086] In an embodiment, step b) and step c) are conducted in a separate vessel to step d), optionally operatively connected to enable substantially continuous operation. Preferably, step d) is conducted in a settling furnace from which the slag can be separated from the base metal matte.

[0087] In an embodiment, the method comprises employing a plurality of vessels arranged in series or parallel, preferably in series.

[0088] In an embodiment, the method is adaptable and/or scalable to a continuous flow or batch-type scenario.

[0089] In an embodiment, the inventive method is adaptable and/or scalable to a continuous flow or batch-type scenario.

[0090] In an embodiment, the method is performed on a continuous or semi- continuous basis. Semi-continuous operation may involve a batch-type process whereby each batch is run in a semi-continuous process. This could be achieved in a plurality of reactors each operating independently of the other or in fluid communication with each other. [0091] In an embodiment, the one or more valuable base metals comprises Li, Au, Ag, Al, Ca, Cr, Co, Cu, Fe, Ga, K, Mg, Mn, Na, Ni, and V.

[0092] In an embodiment, the one or more valuable base metals comprises Li, Mn, Cu, Co, Au, Ag and Ni.

[0093] In an embodiment, the one or more valuable base metals comprises Ni.

[0094] In an embodiment, the one or more valuable base metals comprises Mn.

[0095] In an embodiment, the one or more valuable base metals comprises Cu.

[0096] In an embodiment, the one or more valuable base metals comprises Co.

[0097] In an embodiment, the one or more valuable base metals comprises Au.

[0098] In an embodiment, the one or more valuable base metals comprises Ag.

[0099] In an embodiment, any one or more of the impurities reporting to the slag is present at a concentration between about 0.5% and about 40% of the valuable metals concentration on a molar basis.

[00100] In an embodiment, the inventive method gives rise to a yield (on an extracted valuable metals basis) of between about 1% and about 99.99999%.

[00101] In a preferred embodiment, the inventive method gives rise to a yield (on an extracted valuable metals to end-of-life battery materials basis) of between about 1% and about 100%. Preferably, the yield is between about 10% and about 99.99%. More preferably, the yield is between about 25% and about 99%. More preferably, the yield is between about 50% and about 99%. More preferably, the yield is about 99%.

[00102] This defined range of about 1 to about 100% is intended to encompass the stated endpoints and all yields therebetween. As such, the claimed range includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,

30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,

54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77,

78, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 and 100% on an extracted valuable metals to end-of-life battery materials basis, including intermediary values such as 70.5, 71.5, 72.5, 73.5, 74.5, 75.5, 76.5, 77.5, 78.5, 79.5 and 80.5% on an extracted valuable metals to end-of-life battery materials basis.

[00103] In an embodiment, the pyrometallurgical furnace is further defined by an end- of-life battery materials feed concentration between about 0.1 and about 99% w/w.

[00104] The end-of-life battery material feed concentration equates to the weight/weight percentage of solids within the feed to pyrometallurgical furnace. The end-of-life battery materials feed concentration is between about 0.1% w/w and about 99% w/w. As such, the claimed range includes 0.1, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20,

22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58,60, 62, 64, 66, 68,

70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 99% w/w, including intermediary values such as 21, 23, 25, 27, 29, 31, 33, 35, 37 and 39% w/w, etc.

[00105] In a preferred embodiment, the end-of-life battery materials feed concentration is between about 0.1 and about 99.99% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is between about 40 and about 98% w/w. In another preferred embodiment, the predetermined end of life battery materials feed concentration is between about 50 and about 95% w/w. In another preferred embodiment, the predetermined solids concentration is between about 55 and about 94% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is between about 75 and about 90% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is about 80% w/w.

[00106] In a preferred embodiment, the end-of-life battery materials concentration is between about 0.1 and about 99.99% w/w. In another preferred embodiment, the end-of- life battery materials concentration is between about 10 and about 99% w/w. In another preferred embodiment, the end-of-life battery materials concentration is between about 50 and about 98% w/w. In another preferred embodiment, the end-of-life battery materials concentration is between about 60 and about 97% w/w. In another preferred embodiment, the end-of-life battery materials concentration is between about 65 and about 96% w/w.

[00107] In a preferred embodiment, the end-of-life battery materials concentration is between about 0.1 and about 99.9999% w/w. In another preferred embodiment, the end- of-life battery materials concentration is between about 1 and about 98% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is between about 5 and about 95% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is between about 60 and about 90% w/w. In another preferred embodiment, the end-of-life battery materials feed concentration is between about 70 and about 85% w/w.

[00108] In an embodiment, the end-of-life battery materials is obtained by breaking or crushing the end-of-life battery waste to a predetermined average particle size.

[00109] In an embodiment, the end-of-life battery materials have an average particle size between about 0.1 pm and about 1000 |am.

[00110] In an embodiment, the end-of-life battery materials have an average particle size between about 25 nm and about 1000 mm (10⁹ nm). In other embodiments, the end- of-life battery materials have an average particle size between about 25, 50, 75, 100, 10³, 10⁴, 10⁵, 10⁶, 10⁷, 10⁸ or 10⁹ nm. The larger average particle sizes (e.g., 10⁷ to 10⁹ nm) allow for, in some embodiments, whole (z.e., not crushed/shredded) batteries to be used in the method of the invention.

[00111] In an embodiment, the end-of-life battery materials have an average particle size between about 500 nm and about 500 pm.

[00112] In an embodiment, the end-of-life battery materials have an average particle size between about 2500 pm and about 100 pm.

[00113] In an embodiment, the end-of-life battery materials have an average particle size of about 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500 or 10,000 nm (i.e., 10 pm). In an embodiment, the end-of-life battery materials have an average particle size of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490 or about 500 pm.

[00114] In an embodiment, the end-of-life battery materials have an average particle size between about 500 nm and about 500 pm. In a preferred embodiment, the end-of- life battery materials have an average particle size between about 2000 nm and about 450 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 4000 nm and about 400 pm. In a preferred embodiment, the end-of- life battery materials have an average particle size between about 6000 nm and about 350 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 8000 nm and about 300 pm. In a preferred embodiment, the end-of- life battery materials have an average particle size between about 10,000 nm and about 250 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 12,000 nm and about 200 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 14,000 nm and about 150 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 16,000 nm and about 100 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 20,000 nm and about 90 |im. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 25,000 nm (i.e., 25 pm) and about 80 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 30 pm and about 70 pm. In a preferred embodiment, the end-of-life battery materials have an average particle size between about 35 pm and about 60 pm. [00115] The average particle size of the end-of-life battery materials is between about 500 nm and about 500 pm, more preferably, between about 40 pm and about 60 pm, and most preferably about 44 pm. This defined range is intended to encompass the stated endpoints and all average particle sizes therebetween. As such, the claimed range includes 0.5 pm (i.e., 500 nm), 1, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480 and 500 pm, including intermediary values such as 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 and 99 pm, etc.

[00116] In an embodiment, the end-of-life battery materials is untreated (chemical, mechanical, physical such as heating or pyrolysis) prior to use.

[00117] In an embodiment, the end-of-life battery materials is treated (chemical, mechanical and/or physical such as heating or pyrolysis) prior to use.

[00118] In an embodiment, electrolytes from a battery are still present in the end-of- life battery materials.

[00119] In another embodiment, electrolytes from a battery are not still present in the end-of-life battery materials.

[00120] In an embodiment, the end-of-life battery materials may comprise one or more of a binder or electrolyte. Preferably the electrolyte is lithium hexafluorophosphate (LiPFe). Preferably, the binder is selected from one or more of fluoroethylene carbonate (FEC), 1,3-propane sultone (PS), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), polyvinylidene fluoride (PVDF) or propylene carbonate (PC).

[00121] In an embodiment, the pyrometallurgical furnace comprises any suitable pyrometallurgical vessel or furnace.

[00122] In an embodiment, the pyrolytic vessel or furnace is a bath or blast furnace.

[00123] In an embodiment, the pyrolytic vessel or furnace is an ISASMELT™ furnace. An ISASMELT™ furnace is an upright-cylindrical shaped steel vessel that is lined with refractory bricks. There is a molten bath of slag, matte or metal (depending on the application) at the bottom of the furnace. A steel lance is lowered into the bath through a hole in the roof of the furnace, and air or oxygen-enriched air that is injected through the lance into the bath causes vigorous agitation of the bath. Mineral concentrates or materials for recycling are dropped into the bath through another hole in the furnace roof or, in some cases, injected down the lance. These feed materials react with the oxygen in the injected gas, resulting in an intensive reaction in a small volume (relative to other smelting technologies).

[00124] ISASMELT™ lances contain one or more devices called “swirlers” that cause the injected gas to spin within the lance, forcing it against the lance wall, cooling it. The swirler consists of curved vanes around a central pipe forming an annular flow. They are designed to minimise pressure losses by changing the angle from axial to tangential thus creating a strong vortex. The vortex helps mix liquids and solids with oxygen in the bath. The cooling effect results in a layer of slag “freezing” on the outside of the lance. This layer of solid slag protects the lance from the high temperatures inside the furnace. The tip of the lance that is submerged in the bath eventually wears out, and the worn lance is easily replaced with a new one when necessary. The worn tips are subsequently cut off and a new tip welded onto the lance body before it is returned to the furnace.

[00125] ISASMELT™ furnaces typically operate in the range of 1000-1500 °C, depending on the application. The refractory bricks that form the internal lining of the furnace protect the steel shell from the heat inside the furnace. The products are removed from the furnace through one or more “tap holes” in a process called “tapping”. This can be either continuous removal or in batches, with the tap holes being blocked with clay at the end of a tap, and then reopened by drilling or with a thermic lance when it is time for the next tap. Alternatively, a slag notch or underflow weir can be used to continuously remove molten materials from the furnace. The products are allowed to separate in a settling vessel, such as a rotary holding furnace or an electric furnace.

[00126] While smelting sulfide concentrates, most of the energy needed to heat and melt the feed materials is derived from the reaction of oxygen with the sulfur and iron in the concentrate. However, a small amount of supplemental energy is required. ISASMELT™ furnaces can use a variety of fuels, including coal, coke, petroleum coke, oil and natural gas. The solid fuel can be added through the top of the furnace with the other feed materials, or it can be injected down the lance. Liquid and gaseous fuels are injected down the lance.

[00127] According to a second aspect of the present invention there is provided one or more valuable metals, when extracted from end-of-life battery waste by a method as defined according to the first aspect of the present invention.

[00128] In an embodiment, the one or more valuable metals is selected from the group consisting of: Li, Mn, Cu, Co, Au, Ag and Ni.

[00129] According to a third aspect of the present invention there is provided an apparatus for the extraction of one or more valuable base metal/s from end-of-life battery waste, the apparatus comprising:

[00130] a) means for subjecting the end-of-life battery waste to a pyrometallurgical furnace defined by a turbulent bath comprising:

[00131] one or more low temperature (<900 °C) sulfidising agent/s;

[00132] one or more flux/es;

[00133] one or more fuel/s;

[00134] thereby to provide for an oxygen partial pressure of between about 10'¹³ and about 10'⁴ atm;

[00135] b) means for forming a base metal matte and a slag, the slag comprising less than about 5 wt.% base metal/s with the balance reporting to the matte; and

[00136] c) means for separating the matte and the slag.

[00137] In an embodiment, the one or more valuable metals comprise Li, Mn, Cu, Co, Au, Ag and Ni.

[00138] In an embodiment, the apparatus comprises a plurality of reactors arranged in fluid communication in series.

[00139] In an embodiment, the apparatus comprises a plurality of reactors arranged in fluid communication in parallel.

[00140] In a preferred embodiment, the apparatus further comprises means for effecting an initial milling step, whereby the end-of-life battery materials is milled to a predetermined average particle size (as defined above) prior to being provided to step a).

[00141] In a preferred embodiment, the inventive apparatus further comprises filtration means, for filtering off any precipitated respective metal sulfate following extraction from the end-of-life battery waste.

[00142] In an embodiment, the apparatus is used for performing a method as defined according to the first aspect of the present invention.

[00143] According to a fourth aspect of the present invention there is provided a metal sulfide when extracted within a matte by a method as defined according to the first aspect of the present invention.

[00144] In an embodiment, the metal sulfide comprises LiySx within the matte.

[00145] In an embodiment, the metal sulfide comprises Mn_ySx within the matte.

[00146] In an embodiment, the metal sulfide comprises Cu-S within the matte.

[00147] In an embodiment, the metal sulfide comprises Co_ySx within the matte.

[00148] In an embodiment, the metal sulfide comprises Au_ySx within the matte.

[00149] In an embodiment, the metal sulfide comprises AgySx within the matte.

[00150] In an embodiment, the metal sulfide comprises NiySx within the matte.

[00151] In an embodiment, the metal sulfide comprises Fe_ySx within the matte.

[00152] In preferred embodiments of the second and fourth aspects, the process parameters are as defined above in respect of the first and third aspects of the present invention.

[00153] Following completion of step c), the resultant metal sulfide/s are solidified from solution, or optionally upgraded or separated prior to such solidification. The metal sulfide may be converted back to their respective elemental valuable metals via conventional techniques.

[00154] The slag is either discarded or subjected to a secondary recycling process, for instance, to recover valuable metals that are not recoverable via the inventive method.

Detailed Description of a Preferred Embodiment

[00155] The present invention relates to a method for the pyrometallurgical processing of lithium-ion batteries, mixed with a sulfidising agent, which may at least partially overcome the known disadvantages of past methods for high temperature lithium-ion battery treatment. Such a processing method is presented in Figure 1.

[00156] Due to the lack of sulfur in the lithium-ion battery, a sulfur containing matte phase is not able to be produced without the addition of a sulfidising agent. Those skilled in the art will understand that a range of sulfidising agents can be used to introduce sulfur into the smelting process. However, the selection of a cheap and suitable agent is not currently known to those in the industry.

[00157] The sulfidising agent that is currently used in industry is elemental sulfur, injected as a liquid into a molten alloy phase or a pre-reduced calcine. This is performed in nickel laterite smelting flowsheets. However, if element sulfur is added to a bath smelting furnace processing lithium-ion batteries, like an ISASMELT™ furnace, some of the sulfur may combust before it can react in the bath.

[00158] An alternative sulfidising agent is a molten matte from a primary base metal smelter. This is performed at some primary copper and primary nickel smelters, where black mass and other materials are added into the converting vessels. However, this requires a smelter to have a large quantity of base metal sulfide concentrates. This prevents the recovery of base metals from lithium-ion batteries in locations where these base metal sulfide concentrates are unable to be obtained.

[00159] An alternative sulfidising agent is pyrite (or a pyrite containing concentrate), which can be fed into the bath smelting furnace and react with the base metal alloy to form a matte. However, if pyrite (or a pyrite containing concentrate) is added to the process, the slag chemistry will be modified, and the smelting process will become more challenging.

[00160] The use of gypsum is not currently known to those processing lithium-ion batteries. This sulfidising agent contains both sulfur (as a sulfate) and lime, both of which are required in the process to decrease the required smelting temperature. The lime in the gypsum is used to flux the slag and the sulfur reacts to form a matte phase. Unlike elemental sulfur, the sulfur in the gypsum will not burn as it enters the furnace and will be reduced once it has been digested in the bath. Unlike pyrite (or iron sulfide containing concentrates), the gypsum does not contain iron and will not impact the slag chemistry. In contrast to both elemental sulfur and pyrite concentrates, the recovery of sulfur to the matte (from gypsum) will be much higher due to kinetic limitations and the avoidance of S2(g) generation (as an intermediate step).

[00161] The ISASMELT™ furnace injects oxygen-enriched air, and sometimes fuel, into a molten slag that smelts the incoming feed materials in a turbulent bath. A person skilled in the art can select the correct ratio of oxygen-enriched air and fuel so that the oxygen potential of the furnace is maintained in the range of 10'⁷ to 10" ¹¹ atm.

[00162] Those skilled in the art will understand that the ratio of feed materials, sulfidising agents and fluxes added to the ISASMELT™ furnace must be carefully chosen to obtain a fluid slag and matte. Moreover, the matte phase can be sulfur deficient such that it contains between 1 and 22 wt.% sulfur, when it leaves that ISASMELT™ furnace.

[00163] Those skilled in the art will understand that the oxygen-enriched air injected through the ISASMELT lance, and feed materials charged to the furnace, should be added in a ratio that will obtain partial combustion, such that many of the gaseous compounds are substantially oxidised but leaving some uncombusted FeS, ZnS, NiS, Cu₂S, CoS, MnS, Fe, Ni, Cu, Zn, Co and Mn to form a molten matte in the bottom of the furnace.

[00164] A suitable atmosphere for partial combustion of the charge would be an oxygen partial pressure between 10'¹³ and 10'⁴ atm, more suitably it will be an oxygen partial pressure between 10" ¹¹ and 10'⁶ atm and more suitably still, it will be an oxygen partial pressure between 10'¹⁰⁵ and 10'^{8 5} atm. The resulting matte will then be suitable for addition to a base metal refinery for downstream processing.

Examples

[00165] Examples of the inventive process are given below in Tables 1 through 11:

Table 1. Exemplary inputs used in, and outputs obtained from the inventive method

[00166] As demonstrated above in respect of Table 7, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 243 kg and a nickel content of 47.8 wt.%, a copper content of 22.0 wt.%, a cobalt content of 10.6 wt.% and a sulfur content of 10.0 wt.%. By comparison, the 189 kg of S-containing slag contained only 0.2 wt.% Ni, 0.6 wt.% Cu and 0.5 wt.% Co.

Table 2. Exemplary inputs used in, and outputs obtained from the inventive method

[00167] As demonstrated above in respect of Table 2, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica. Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 254 kg and a nickel content of 51.6 wt.%, a copper content of

23.8 wt.%, a cobalt content of 13.2 wt.% and a sulfur content of 8.8 wt.%. By comparison, the 218 kg of S-containing slag contained only 0.3 wt.% Ni, 0.4 wt.% Cu and 0.6 wt.% Co.

[00168] As demonstrated below in respect of Table 3a, to an initial mass of 500 kg spent nickel-containing batteries was added 120 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 256 kg and a nickel content of 51.0 wt.%, a copper content of 23.3 wt.%, a cobalt content of 13.1 wt.% and a sulfur content of 9.9 wt.%. By comparison, the 228 kg of S-containing slag contained only 0.3 wt.% Ni, 0.7 wt.% Cu and 0.7 wt.% Co.

[00169] As demonstrated below in respect of Table 3b, to an initial mass of 500 kg spent nickel-containing batteries was added 120 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 253 kg and a nickel content of 51.5 wt.%, a copper content of

23.9 wt.%, a cobalt content of 12.4 wt.% and a sulfur content of 10.9 wt.%. By comparison, the 235 kg of S-containing slag contained only 0.6 wt.% Ni, 0.5 wt.% Cu and 1.5 wt.% Co.

Table 3a. Exemplary inputs used in, and outputs obtained from the inventive method

Table 3b. Exemplary inputs used in, and outputs obtained from the inventive method

Table 3c. Exemplary inputs used in, and outputs obtained from the inventive method

[00170] As demonstrated above in respect of Table 3c, to an initial mass of 500 kg spent nickel-containing batteries was added 120 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 257 kg and a nickel content of 50.9 wt.%, a copper content of 22.9 wt.%, a cobalt content of 13.3 wt.% and a sulfur content of 8.5 wt.%. By comparison, the 224 kg of S-containing slag contained only 0.3 wt.% Ni, 1.2 wt.% Cu and 0.4 wt.% Co.

[00171] As demonstrated in respect of Table 4, below, to an initial mass of 500 kg spent nickel-containing batteries was added 80 kg of gypsum and 20 kg silica. Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 253 kg and a nickel content of 51.8 wt.%, a copper content of 24.0 wt.%, a cobalt content of 13.4 wt.% and a sulfur content of 7.1 wt.%. By comparison, the 204 kg of S-containing slag contained only 0.1 wt.% Ni, 0.3wt.% Cu and 0.4 wt.% Co.

Table 4. Exemplary inputs used in, and outputs obtained from the inventive method

[00172] As demonstrated in respect of Table 5, below, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 257 kg and a nickel content of 51.1 wt.%, a copper content of 23.2 wt.%, a cobalt content of 13.4 wt.% and a sulfur content of 7.2 wt.%. By comparison, the 210 kg of S-containing slag contained only 0.2 wt.% Ni, 0.9 wt.% Cu and 0.2 wt.% Co. Table 5. Exemplary inputs used in, and outputs obtained from the inventive method

[00173] As demonstrated in respect of Table 6, below, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 254 kg and a nickel content of 44.7 wt.%, a copper content of 23.7 wt.%, a cobalt content of 20.1 wt.% and a sulfur content of 8.3 wt.%. By comparison, the 216 kg of S-containing slag contained only 0.2 wt.% Ni, 0.6 wt.% Cu and 0.7 wt.% Co.

Table 6. Exemplary inputs used in, and outputs obtained from the inventive method

[00174] As demonstrated below in respect of Table 7, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 256 kg and a nickel content of 55.8 wt.%, a copper content of 23.6 wt.%, a cobalt content of 8.9 wt.% and a sulfur content of 8.5 wt.%. By comparison, the 214 kg of S-containing slag contained only 0.2 wt.% Ni, 0.5 wt.% Cu and 0.3 wt.% Co.

Table 7. Exemplary inputs used in, and outputs obtained from the inventive method

Table 8. Exemplary inputs used in, and outputs obtained from the inventive method

[00175] As demonstrated in respect of Table 8, above, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 253 kg and a nickel content of 39.6 wt.%, a copper content of 35.8 wt.%, a cobalt content of 13.3 wt.% and a sulfur content of 8.3 wt.%. By comparison, the 217 kg of S-containing slag contained only 0.2 wt.% Ni, 0.8 wt.% Cu and 0.6 wt.% Co.

[00176] As demonstrated in respect of Table 9, below, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 256 kg and a nickel content of 59.1 wt.%, a copper content of 15.7 wt.%, a cobalt content of 13.3 wt.% and a sulfur content of 8.4 wt.%. By comparison, the 214 kg of S-containing slag contained only 0.2 wt.% Ni, 0.4 wt.% Cu and 0.4 wt.% Co.

Table 9. Exemplary inputs used in, and outputs obtained from the inventive method

Table 10. Exemplary inputs used in, and outputs obtained from the inventive method

[00177] As demonstrated in respect of Table 10, above, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica.

Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 249 kg and a nickel content of 49.1 wt.%, a copper content of 24.2 wt.%, a cobalt content of 13.6 wt.% and a sulfur content of 8.5 wt.%. By comparison, the 223 kg of S-containing slag contained only 0.2 wt.% Ni, 0.6 wt.% Cu and 0.5 wt.% Co.

Table 11. Exemplary inputs used in, and outputs obtained from the inventive method

[00178] Finally, as demonstrated in respect of Table 11, above, to an initial mass of 500 kg spent nickel-containing batteries was added 100 kg of gypsum and 20 kg silica. Following the pyrometallurgical extraction method defined in claim 1, the matte/alloy obtained had a mass of 259 kg and a nickel content of 52.8 wt.%, a copper content of 23.3 wt.%, a cobalt content of 13.1 wt.% and a sulfur content of 8.3 wt.%. By comparison, the 210 kg of S-containing slag contained only 0.2 wt.% Ni, 0.5 wt.% Cu and 0.5 wt.% Co.

[00179] The general method employed above amply demonstrates that modified pyrometallurgical conditions employing a furnace for the extraction of metal sulfides from end-of-life battery materials is surprisingly efficacious.

[00180] The methodology further demonstrates the efficacy of modified pyrometallurgical conditions employing a furnace for other valuable metal recycling from end-of-life battery materials. Such metals preferably include Mn, Ni, Co and/or Li.

Economic and Environmental Implications

[00181] The above examples demonstrate that, contrary to the accepted wisdom of using hydrometallurgical or pyrometallurgical processes to extract valuable metals such as lithium from end-of-life battery materials, such valuable metals can also be extracted under the relatively mild conditions prescribed by the present invention. Such a process engenders many advantages, without the negative consequences in respect of metal selectivity, cost, environmental damage, without the need for one or more pre-treatment or subsequent purification/extraction steps and without any in-depth understanding of the end-of-life battery materials chemistry.

[00182] The inventive method of extracting valuable metals from end-of-life battery waste engenders many advantages over the methods prescribed in the prior art. In using a relatively mild pyrolytic furnace at only moderate temperature, pressure - and over a relatively short reaction period, the inventive method is genuinely counterintuitive.

Moreover, as compared with the representative prior art methods, the present invention provides for an environmentally friendly approach to what has traditionally been a somewhat damaging and wasteful pursuit.

[00183] More specifically, the use of sulfur to enhance the extraction of valuable metals under low heating conditions represents an environmentally friendly approach compared to many /most known lithium-ion battery recycling methods.

Industrial Applicability

[00184] With ever-increasing global demand for valuable metals such as lithium, manganese, nickel, and cobalt, set against a finite mineral supply and processing difficulties with traditional extraction methods, recycling is essential. The economic implications of successfully developing and commercialising the inventive technology may be significant.

[00185] Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS

1. A method for the extraction of one or more valuable base metal/s from end-of-life battery waste, the method comprising the steps of: a) obtaining the end-of-life battery waste having a content of the one or more valuable base metal/s; b) subjecting the end-of-life battery waste to a pyrometallurgical furnace defined by a molten turbulent bath comprising: one or more low temperature (<900 °C) sulfidising agent/s; one or more flux/es; one or more fuel/s and/or coolant/s; thereby to provide for an oxygen partial pressure of between about 10’¹³ and about 10'⁴ atm; c) forming a base metal matte and a slag, the slag comprising less than about 5 wt.% base metal/s with the balance reporting to the matte; d) separating the matte from the slag.

2. A method according to claim 1, comprising the step of: e) further refining the base metal matte, thereby separating and purifying one or more valuable base metal/s.

3. A method according to claim 1, wherein the one or more sulfidising agent/s comprise sulfur, gypsum, metal sulfide and/or metal sulfates such as sodium, calcium, magnesium, copper, iron(II), iron(III), hydrogen and lead.

4. A method according to any one of the preceding claims, wherein the one or more sulfidising agent/s is/are added such that the amount of sulfur in the base metal matte is between about 1 and about 28 wt.%.

5. A method according to any one of the preceding claims, wherein the oxygen partial pressure is between about 10'¹⁰⁵ and about 10'⁷ atm.

6. A method according to any one of the preceding claims, wherein the further refining comprises converting the metal sulfide/s present in the base metal matte to their respective chemical or metal products via conventional techniques.

7. A method according to any one of the preceding claims, wherein the pyrometallurgical furnace is further defined by a temperature greater than about 1000 °C.

8. A method according to any one of the preceding claims, wherein step b), step c) and step d) are conducted in a single vessel.

9. A method according to any one of the preceding claims, wherein step b) and step c) are conducted in a separate vessel to step d), optionally operatively connected to enable substantially continuous operation.

10. A method according to claim 9, employing a plurality of vessels arranged in series or parallel, preferably in series.

11. A method according to any one of the preceding claims, adaptable and/or scalable to a continuous flow or batch-type scenario.

12. A method according to any one of the preceding claims, wherein the one or more valuable base metals comprises Li, Au, Ag, Al, Ca, Cr, Co, Cu, Fe, Ga, K, Mg, Mn, Na, Ni, and V.

13. A method according to claim 12, wherein the one or more valuable base metals comprises Li, Mn, Cu, Co, and/or Ni.

14. A method according to any one of the preceding claims, giving rise to a yield (on an extracted valuable metals basis) of between about 1% and about 100%.

15. A method according to any one of the preceding claims, wherein the pyrometallurgical furnace is further defined by an end-of-life battery material feed concentration between about 0.1 and about 90% w/w.

16. A method according to any one of the preceding claims, wherein the end-of-life battery waste is obtained by breaking or crushing an end-of-life battery to a predetermined average particle size.

17. A method according to claim 16, wherein the end-of-life battery waste has an average particle size between about 25 nm and about 1000 mm.

18. A method according to any one of the preceding claims, wherein the end-of-life battery waste is untreated (chemical, mechanical, physical such as heating or pyrolysis) prior to use.

19. A method according to any one of claims 1 to 17, wherein the end-of-life battery waste is treated (chemical, mechanical and/or physical such as heating or pyrolysis) prior to use.

20. A method according to any one of the preceding claims, wherein electrolytes from a battery are/are not still present in the end-of-life battery waste.

21. A method according to any one of the preceding claims, wherein the pyrometallurgical furnace comprises any suitable pyrolytic vessel or furnace.

22. A method according to claim 21, wherein the pyrolytic vessel or furnace is a bath or blast furnace.

23. A method according to claim 21 or claim 22, wherein the pyrolytic vessel or furnace is an ISASMELT™ furnace.

24. One or more valuable metals, when extracted from end-of-life battery materials by a method as defined according to any one of the preceding claims.

25. One or more valuable metals according to claim 24, selected from the group consisting of: Li, Mn, Cu, Co, Au, Ag and Ni.

26. An apparatus for the extraction of one or more valuable base metal/s from end-of- life battery waste, the apparatus comprising: a) means for subjecting the end-of-life battery waste to a pyrometallurgical furnace defined by a turbulent bath comprising: one or more sulfidising agent/s; one or more flux/es; one or more fuel/s and/or coolant/s; thereby to provide for an oxygen partial pressure of between about 10’¹³ and about 10'⁴ atm; b) means for forming a base metal matte and a slag, the slag comprising less than about 5 wt.% base metal/s with the balance reporting to the matte; and c) means for separating the matte and the slag.

27. An apparatus according to claim 26, wherein the one or more valuable metals comprise Li, Mn, Cu, Co, Au, Ag and/or Ni.

28. An apparatus according to claim 26 or claim 27, comprising a plurality of reactors arranged in fluid communication in series.

29. An apparatus according to any one of claims 26 to 28, when used for performing a method as defined according to any one of claims 1 to 23.

30. A metal sulfide when produced by a method as defined according to any one of claims 1 to 23.