Extraction of Metals from Lithium-Ion Battery Materials

Abstract

The present invention relates to a method for extracting metals from the black mass of a lithium-ion battery, said black mass containing the anode and cathode materials of the battery, said cathode material comprising lithium, nickel and cobalt.Furthermore, the present invention relates to an apparatus suitable for use in this method.

Description

Technical Field

[0001] The present invention relates to a method for extracting metals from lithium-ion battery materials, in particular from black mass obtained from such battery materials. Such black mass mainly contains cathode metals and anode materials, and the cathode metals usually include lithium, nickel and cobalt, and possible additional cathode metals are manganese and aluminum. The present invention also relates to an apparatus suitable for use in this method.

Background Art

[0002] The use of lithium-ion batteries has been steadily increasing in recent years, and its importance seems to be further increasing as the development of new electric vehicles continues. The cathodes of lithium-ion batteries contain several transition metals, and these transition metals can become valuable when recycled as new batteries or recovered from the batteries for other purposes.

[0003] To separate these cathode metals from other battery components, dry metallurgical processes have been used so far, but these are high-cost processes with a large environmental impact and tend to result in significant metal losses. Therefore, separation by hydrometallurgy has become more common.

[0004] The hydrometallurgical separation of metals from lithium-ion batteries proceeds through the recovery of black mass containing cathode metals and anode materials, from which other coarse solid battery components such as wiring and plastic or steel parts have already been removed.

[0005] The next step in metal recovery after the formation of black mass is usually to solubilize the cathode metals using, for example, acid leaching, and optionally to separate the cathode metals from other components of the black mass using a reducing agent to increase the solubility of the target metals.

[0006] The inventors have now discovered that by optimizing the choice of reagents, acid leaching and subsequent separate metal recovery can be carried out more efficiently, optionally under reducing conditions. Accordingly, a more efficient procedure for solubilizing metal oxides in the hydrometallurgical treatment of black mass can be provided, and as a result, selective recovery of metals in subsequent steps of the method can be achieved.

SUMMARY OF THE INVENTION

[0007] The present invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.

[0008] According to a first aspect of the present invention, there is provided a method for extracting metals from black mass obtained from lithium-ion battery materials, the black mass containing anode materials and cathode materials of the battery. In particular, the metals to be extracted include transition metals, more specifically, at least one of lithium, nickel, and cobalt.

[0009] According to a second aspect of the present invention, there is provided a method for extracting the cathode metal from black mass by utilizing an acid leaching step.

[0010] According to a third aspect of the present invention, there is provided a method comprising acid leaching the metal from black mass in a sulfur environment.

[0011] According to a fourth aspect of the present invention, the leaching is reductive leaching using SO2 as a reducing agent, and a gas containing molecular oxygen is used to provide more efficient solubilization.

[0012] According to a further aspect of the present invention, there is provided an apparatus suitable for use in performing the steps of the method of the present invention.

[0013] Thus, the method of the present invention includes one or more leaching steps, including an acid leaching step, The desired transition metal is usually recovered as a fraction containing at least one of the ions of lithium, cobalt and nickel, and a metal separation step necessary for this purpose, is included.

[0014] Similarly, the device of the present invention one or more leaching units in which a leach solution containing the dissolved cathode material is recovered, a metal separation unit for recovering a fraction containing at least one of the ions of lithium, cobalt and nickel, is provided.

[0015] Accordingly, the present invention relates to the use of SO2 and a gas containing molecular oxygen in the acid leaching of black mass metals, and thus provides a more efficient solubilization of the transition metals contained therein as compared to general leaching procedures.

[0016] The sulfuric acid used in this method forms the basis for the sulfation of the cathode metals in the black mass and is necessary to solubilize these metals. In fact, sulfuric acid can convert the cathode metal with the lowest oxidation number into a more soluble sulfate.

[0017] The gas containing molecular oxygen controls the acidity of the solution and achieves more efficient solubilization, and SO2 converts specific metal ions into a more soluble oxidation state. For example, manganese ions and cobalt ions are present in at least a partially insoluble oxidation state of Mn 4+ and Co 3+ and tend to be converted by a reducing agent into a more soluble state of Mn 2+ and Co 2+ is converted.

[0018] It has been shown in the past that a reducing agent is beneficial for improving the leaching of cobalt and manganese from the cathode material of a lithium-ion battery. The inventors have now discovered that SO2 is a preferred choice of reducing agent because of its ability to supplement the need for acid. Sulfur dioxide has the further advantage of being a gas, thereby eliminating the need for dilution with water and leaving no trace in the solution. In particular, unreacted oxidants or reducing agents can be detrimental in a solvent extraction circuit. This is because the organic matter used in solvent extraction degrades and its performance deteriorates, increasing the need to replace the organic matter used.

[0019] Accordingly, the present invention provides several advantages. In particular, by operating with a sulfate solution, adjusting the pH of the leaching solution to an appropriate operating range, and supplying an oxygen-containing gas to the leaching unit together with a selected reducing agent, namely sulfur dioxide (SO2), both supplied to leaching at appropriate rates, high-efficiency solubilization becomes possible.

[0020] In addition to functioning as a reducing agent that enables the dissolution of metals, SO2 also produces acid and supplements part of the need for sulfuric acid addition.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2a

Figure 2b

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0022] (Definition) As used herein, the term "black mass" is intended to represent a mixture of cathode material and anode material obtained after mechanically separating the components of a battery, and black mass usually contains organic compounds such as compounds derived from the electrolyte of the battery, depending on the pretreatment method of the black mass. "Organic compound" is intended herein to encompass molecules in which one or more carbon atoms are covalently bonded to one or more atoms of hydrogen, oxygen, or nitrogen. Thus, for example, graphite or other allotropes of pure carbon are excluded from this group of compounds. Other compounds that are generally considered to be excluded from this class of compounds, despite meeting the definition, include carbonates and cyanides, and carbon dioxide, when the only carbon in the compound is included in this group. "Anode" is usually formed from, for example, graphite or silicon, which is not solubilized in the leaching of the present invention but is present in the black mass before leaching. "Cathode material" or "cathode metal" contains metal ions such as lithium, nickel, cobalt, manganese (Li, Ni, Co, Mn), usually in the form of oxides. The content of these metals in the black mass is preferably in the range of 1 to 35% by weight in each case. Other examples of cathode components that may be present in the black mass include, usually in small amounts, tin, zirconium, zinc, copper, iron, fluoride, phosphorus, and aluminum (i.e., Sn, Zr, Zn, Cu, Fe, F, P, and Al).

[0023] The present invention relates to a method for extracting metals from black mass of lithium-ion battery materials. The method comprises (a) one or more pretreatment steps in which a fraction of non-metallic material is separated from the black mass and a pretreated black mass containing anode material and cathode material is recovered and preferably further treated by leaching; (b) One or more leaching steps, including acid leaching carried out in a solution containing sulfuric acid by further adding a gas containing sulfur dioxide and molecular oxygen as an extractant, whereby the cathode material of the pretreated black mass is dissolved and a leaching solution containing the dissolved cathode material is recovered, preferably further processed by separating the metal fraction therefrom; (c) A metal separation step in which an initial fraction of the metal material is separated from the leaching solution and a major fraction containing at least one of cobalt, nickel and lithium is recovered; comprising.

[0024] The black mass of a lithium-ion battery usually contains, in addition to both the positive electrode material and the negative electrode material, an electrolyte material containing an organic compound. For the purposes of the present invention, the presence of the organic compound may impede the separation of metals from the leaching solution after the leaching step, so the organic compound is preferably removed from the black mass by the above pretreatment step.

[0025] For example, one or more washing steps can be used as a pretreatment step, preferably carried out by mixing the battery material with water or an organic solvent, most suitably water, whereby materials dissolved or dispersed in the solvent, such as the organic compound, can be separated from the insoluble components of the black mass. Alternatively, one or more heating steps, usually carried out as a pyrolysis or evaporation step, can be used to remove the organic compound, preferably carried out at a temperature of 195 to 470 °C. A further option is to carry out both a washing step and one of the aforementioned heating procedures.

[0026] Thus, the pretreatment step preferably yields a pretreated black mass containing lithium, nickel and cobalt, and optionally manganese, in the form of oxides of the battery positive electrode, more preferably containing no more than 3% by weight, most suitably less than 1.5% by weight of the remaining organic compound.

[0027] In a preferred embodiment of the present invention, at least one fraction of lithium that is typically lost in an optional washing step is reacting a spent washing solution containing a separated fraction of non-metallic material separated from the remaining solids with a phosphate reagent to precipitate lithium therein as lithium phosphate; separating the lithium phosphate precipitate from the remaining washing solution and mixing it with the pretreated black mass to be carried to the next leaching step; is recovered by.

[0028] After the pretreatment step, typically solid / liquid separation is carried out, whereby the pretreated black mass can be carried to the next leaching step and, optionally, mixed with additional metal-containing solids or slurries, such as lithium phosphate precipitate recycled from either the pretreatment step or the metal recovery step.

[0029] In one embodiment of the present invention, only one leaching step is used, which is the acid leaching step carried out in a solution containing sulfuric acid. Thus, typically, acid leaching is carried out by dispersing the pretreated black mass in a solution containing an acid, adding an extractant, and preferably mixing thereafter.

[0030] The temperature during the leaching step is preferably adjustable, whereby the temperature during acid leaching is most preferably maintained at a high level, such as a temperature exceeding 50°C, preferably a temperature of 50 - 95°C, more preferably a temperature of 60 - 90°C. Similarly, the pressure during acid leaching is preferably maintained at atmospheric pressure or a slightly pressurized pressure of 100 - 200 kPa. Usually, the solubilization of the target transition metal is completed within 2 - 6 hours.

[0031] The addition of sulfuric acid is partly used to adjust the pH of the leachate. Thus, the pH of the leaching solution is preferably adjusted to a level of 0 - 5, more preferably 1 - 2, using the sulfuric acid before adding the extractant.

[0032] The efficient solubilization of the desired cathode components is strongly promoted by the presence of a reducing agent. In the present invention, sulfur dioxide (SO2) is used to maintain or further reduce metals such as cobalt and manganese in the washed black mass in a less oxidized state, i.e., to keep these metal ions in the solution phase.

[0033] The gas containing molecular oxygen used for acid leaching is necessary to more efficiently solubilize the cathode metal. This oxygen-containing gas can be selected from any gas or gas mixture containing molecular oxygen, i.e., O2 or O3, preferably in the form of O2, and can be mainly mixed with an inert gas, and it is preferred that other gases mainly function as diluents. For example, the gas can have an oxygen content of 15 to 100% by volume. Usually, this oxygen-containing gas is selected from air containing about 21% by volume of molecular oxygen (O2) or pure molecular oxygen in the form of O2, and undiluted molecular oxygen can cause the need to increase the supply amount of sulfur dioxide, so it is preferably air.

[0034] Regardless of the gas selection, it is preferred to add sulfur dioxide and the gas containing molecular oxygen at a volume ratio of SO2:O2 adjusted to a level of 0.5:1 to 1.5:1, preferably 0.7:1 to 1.3:1. In one embodiment, this ratio is adjusted to a level of 0.5:1 to 0.99:1 such that the content of SO2 is less than the content of O2, and more preferably to a level of 0.7:1 to 0.9:1.

[0035] The supply rates of the oxygen-containing gas and SO2 are preferably combined with the stoichiometric supply rates based on the amount of metal in the pretreated black mass and are most appropriately finely adjusted based on parameters such as the redox potential.

[0036] After the leaching reaction is complete, i.e., after the pretreated black mass has spent a sufficient time, such as 2 to 6 hours, under leaching conditions, solid / liquid separation is typically carried out to recover the leaching solution containing the cathode metal, whereby it can be carried forward to the next step of this method to recover the separate metal fractions.

[0037] In one embodiment of the present invention, the recovery of the major fraction of the metal material containing at least one of cobalt, nickel, and lithium ions preferably precedes one or more steps for separating the initial fraction of the metal material from the leaching solution. The said initial fraction of the metal material (or "initial metal fraction") usually contains at least one of iron, aluminum, calcium, and fluoride ions, and optionally phosphate. The order of this procedure has the advantage that a purification solution for recovering the initial fraction of the metal material is provided because the initial fraction contains materials considered to belong to impurities. These substances can also impair the subsequent recovery of the major fraction, or at least cause a decrease in purity and yield, if they remain in the leaching solution.

[0038] Preferably, the step of separating the initial fraction of the metal material from the leaching solution includes steps for separating two or more, preferably three or four, most suitably all of iron, aluminum, calcium, and fluoride ions. Also, copper and phosphate may be included in these initial fractions. Optionally, a separate copper recovery step may be carried out, preferably before separating the other initial fractions from the solution.

[0039] Typically, the separation of the initial fraction of the metal material is carried out as solvent extraction (SX) aimed at removing impurities such as iron and aluminum from the leaching solution, and optionally includes at least one step of solid separation that is carried out beforehand to remove the said impurities already present in solid form and enhance the selectivity of the solvent extraction.

[0040] In another alternative, the separation of the initial fraction of the metal material involves at least one step, carried out as a precipitation, for example a hydroxide precipitation, aimed at removing impurities such as iron and aluminum and, optionally, phosphates from the leaching solution as a solid fraction.

[0041] In a particularly preferred alternative, the separation of the initial fraction of the metal material involves precipitation, optionally accompanied by the separation of impurities from the leaching solution, followed by solvent extraction, both steps being as described above. The advantage of such a two-stage impurity separation is that the content of impurities such as iron and aluminum in the leaching solution thus purified is further reduced. It is particularly preferred to carry out the precipitation before the solvent extraction in such a two-stage separation of the initial metal fraction. This is because it promotes the high selectivity in the solvent extraction.

[0042] When copper is recovered separately, this copper recovery step is preferably carried out before the said initial fraction of the metal material is separated from the leaching solution, as copper can subsequently be recovered and, more importantly, can have an adverse effect on the quality of the product.

[0043] Since the acid leaching step is carried out in an acidic solution, the first metal separation step needs to withstand acidic conditions. This requirement is met by the separation of the initial metal fraction.

[0044] The separation and recovery of the metal can be carried out using various reactions and procedures such as further leaching or washing steps, solvent extraction, precipitation, ion exchange steps, and electrowinning steps. However, it is preferred to use at least one solvent extraction for the separation of the initial metal fraction. This is because it increases the purity of the residual solution and facilitates the subsequent recovery of the main fraction, especially the recovery of cobalt and nickel. As a result, all the metals in the main fraction can be recovered in high yield and high purity, usually as battery-grade materials.

[0045] As described above, the recovery of the main fraction of the metal includes the step of recovering at least one of the ions of cobalt, nickel, and lithium, and optionally manganese, but the order of these recoveries can vary.

[0046] In particular, the recovery of the main fraction includes the step of recovering two or more, preferably three or four, and most preferably all of the ions of manganese, cobalt, nickel, and lithium from the leaching solution, and lithium is one of the preferred metals to be recovered together with nickel and cobalt.

[0047] Accordingly, at least one of lithium, nickel, and cobalt is recovered, optionally together with manganese, and preferably at least two of manganese, lithium, cobalt, and nickel, more preferably two or three of them, and most preferably all four of them are recovered. Usually, manganese, cobalt, and nickel are recovered before the lithium.

[0048] Accordingly, the recovery of lithium is preferably carried out after the separation of the initial metal fraction, and more preferably also after any of manganese, cobalt, and nickel present in the leaching solution has been recovered. Using this preferred order of steps results in a situation where lithium can be recovered from a high-purity lithium-containing solution.

[0049] Usually, lithium can be recovered as is by reacting it with its carbonate or phosphate, or alternatively can be converted to lithium hydroxide, for example by crystallization to obtain pure hydroxide crystals, by producing a product fraction.

[0050] A further option for lithium recovery is to use solvent extraction, followed by further conversion or crystallization. The advantage of this procedure is that the recovery rate of lithium is even higher.

[0051] In one embodiment of the present invention, lithium is recovered in its carbonate form, generating a product fraction that can be recovered by solid / liquid separation. The solid product fraction is either collected as is or further converted, for example, to lithium hydroxide. Next, the liquid fraction is further reacted with a phosphate reagent, and optionally another precipitation reagent, resulting in the precipitation of the remaining lithium therein as a lithium phosphate precipitate. This precipitate can be recycled to the leaching step, for example, by combining it with the carbonate or phosphate product fraction or by mixing it with the pretreated black mass. A further option is to carry the precipitate fraction to each of these.

[0052] The phosphate reagent used above can be selected from any phosphate of an alkali metal or alkaline earth metal. However, sodium phosphate (Na3PO4) is preferred as it does not introduce new cations into the reaction mixture and has appropriate reactivity.

[0053] The optional precipitation reagent preferably functions by raising the pH of the solution and thereby promoting the precipitation of the desired lithium phosphate, and is selected from alkaline agents such as sodium hydroxide.

[0054] The recovery of nickel is also preferred, particularly performed on the leaching solution after the separation of the initial metal fraction, usually simultaneously with or immediately after the recovery of cobalt, more preferably after the recovery of cobalt, and most appropriately before the recovery of lithium. Similarly, it is preferred to perform nickel recovery after the optional recovery of manganese.

[0055] The nickel recovery can be carried out, for example, using solvent extraction (SX), which produces a fairly pure nickel sulfate solution (NiSO4). This solution can be further purified, optionally, for example by ion exchange (IX), and then crystallization can be carried out, or the precipitate to hydroxide or carbonate or the sulfate solution can be used as is, without crystallization or precipitation, for example in the preparation of a new cathode material. The optional solvent extraction for nickel recovery is most appropriately carried out using an extraction chemical having a carboxylic acid functional group, and one example of a commercially available suitable extraction chemical is Versatic (registered trademark) 10, neodecanoic acid.

[0056] Cobalt recovery is also preferably carried out on the leach solution after separation of the initial metal fraction, usually simultaneously with or immediately before nickel recovery, more preferably before nickel recovery, and most appropriately also before lithium recovery. Similarly, it is preferred to carry out cobalt recovery after optional manganese recovery.

[0057] The preferred option for cobalt recovery is solvent extraction (SX), which produces a fairly pure cobalt sulfate solution (CoSO4). This solution can be further purified, optionally, for example by ion exchange (IX), and then crystallization can be carried out, or the precipitate to hydroxide or carbonate or the sulfate solution can be used as is, without crystallization or precipitation, for example in the preparation of a new cathode material. Any solvent extraction for cobalt recovery is most appropriately carried out using an extraction chemical having a carboxylic acid functional group, such as a phosphinic acid functional group, and one example of a commercially available suitable extraction chemical is Cyanex (registered trademark) 272, also known as trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate.

[0058] In an alternative method of proceeding with the metal separation step, as indicated above, cobalt and nickel can be recovered simultaneously from the leach solution, for example, by solvent extraction or precipitation into hydroxides or carbonates, thus producing a sulfate solution which can optionally be further purified by ion exchange (IX). Alternatively, the sulfate solution can be used as such, without crystallization or precipitation, for example, in the preparation of a new cathode material.

[0059] According to one embodiment of the present invention, the metal separation step includes a step of recovering manganese from the leach solution, and the recovery of manganese is also carried out after the separation of the initial metal fraction. Preferably, manganese is recovered before nickel or cobalt, and most suitably, it is recovered before any of nickel, cobalt or lithium is recovered.

[0060] Options for said manganese recovery include solvent extraction, precipitation and crystallization, or solvent extraction followed by precipitation or crystallization. One particularly preferred option is to utilize oxidative precipitation using sulfur dioxide, SO2, and air to form manganese dioxide, MnO2.

[0061] The method of the present invention can be carried out with any suitable apparatus or device equipped with the units and equipment necessary to carry out the steps of the method.

[0062] In one embodiment of the present invention, the above method is for recovering a pretreated black mass containing an anode material and a cathode material, which separates the fraction of non-metallic components from the black mass and is preferably carried out via a suitable connection to a downstream leaching unit 2, one or more pretreatment units 1 Dissolve the cathode material of the pretreated black mass, and preferably recover the leaching solution containing the dissolved cathode material, which is intended to be carried out via an appropriate connection to the downstream separation unit 3, in one or more leaching units 2, wherein at least one leaching unit 2 is in the form of an acid leaching unit 21 having an inlet 211 for sulfuric acid and an extractant. One or more leaching units 2, A metal separation unit 3 for separating a metal material from the leaching solution and recovering a fraction containing at least one of cobalt, nickel and lithium as a product fraction. It is carried out using the apparatus of FIG. 1 comprising.

[0063] In one embodiment of the present invention, using the various options shown in FIGS. 2a and 2b, the pretreatment unit 1 includes a washing unit 11 and / or a heating unit 12 for removing non-metallic components such as organic compounds from the black mass, and the heating unit 12 is optimally selected from a pyrolysis unit 121 or an evaporation unit 122. The optional washing unit 11 preferably further comprises a water inlet.

[0064] The leaching unit 2 usually consists only of the acid leaching unit 21, which preferably comprises an inlet 211 required for sulfuric acid and an extractant, and means 212 for adjusting the temperature which can incorporate either heating or cooling, as shown in FIGS. 2a and 2b.

[0065] The metal separation unit 3 preferably includes several subunits, and its preferred options are as shown in FIGS. 2a and 2b. All subunits usually have additional subunits (e.g., solvent extraction units, ion exchange units, precipitation units, electro-winning units, washing units, or solid / liquid separation units) required to carry out the intended reaction, recycle lines, inlets and outlets.

[0066] Preferably, one or more units 33, 34, 35, 36 for recovering the major fraction of the metal material containing at least one of cobalt, nickel, and lithium ions are preceded by one or more units 31, 32 for separating the initial fraction of the metal material from the leaching solution, and the units 31, 32 for separating the initial fraction most preferably include at least one solvent extraction unit.

[0067] When copper is separately recovered within the apparatus, the copper recovery unit 31 is preferably arranged upstream of the other unit 32 for separating the initial metal fraction from the leaching solution.

[0068] For performing the separation and recovery, various types of units and facilities such as additional leaching or washing units, solvent extraction units, precipitation units, ion exchange units, and electro-winning units can be utilized. However, solvent extraction units are preferred. In particular, it is preferred to utilize at least one solvent extraction unit for separating the initial metal fraction. More preferably, solvent extraction is preceded by a solid separation unit, which is then optionally preceded by a precipitation unit for such impurities.

[0069] Accordingly, the units 33, 34, 35, 36 for recovering the major fraction of the metal material include units for recovering at least one of cobalt, nickel, and lithium ions arranged in any suitable order.

[0070] In a preferred embodiment of the present invention, the units 34, 35 for recovering at least one of cobalt and nickel are located upstream of the unit 36 for recovering lithium, which preferably includes a subunit for reacting lithium with the corresponding carbonate or phosphate, and optionally followed by a subunit for further converting lithium to lithium hydroxide, which may then be followed by a crystallization subunit.

[0071] In another preferred embodiment of the present invention, a unit 33 for recovering manganese is included in the apparatus and is located upstream of units 34, 35, 36 for recovering at least one of cobalt, nickel, and lithium.

[0072] In another method of selecting and arranging the metal separation unit 3, cobalt and nickel are recovered in the same unit 34 / 35.

[0073] It should be understood that the embodiments of the present invention disclosed herein are not limited to the specific structures, process steps, or materials disclosed herein, but extend to their equivalents as would be recognized by those skilled in the relevant art. It should also be understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting.

[0074] References to one embodiment throughout this specification mean that the particular features, structures, or characteristics described in connection with that embodiment are included in at least one embodiment of the invention. Thus, the phrases "in one embodiment" or "in an embodiment" that appear in various places throughout this specification are not necessarily all referring to the same embodiment. For example, when referring to a numerical value using terms such as about or substantially, the exact numerical value is also disclosed.

[0075] As used herein, a plurality of items, structural elements, components, and / or materials may be presented in a common list for convenience. However, these lists should be construed as if each element of the list is separately identified as a distinct and unique element. Further, various embodiments and examples of the present invention may be referred to herein with alternatives for their various components. It should be understood that such embodiments, examples, and alternatives should not be construed as factual equivalents of each other, but rather as separate and autonomous expressions of the present invention.

[0076] Furthermore, the described features, structures, or characteristics may be combined in any suitable way in one or more embodiments.

[0077] The foregoing examples illustrate the principles of the present invention in one or more particular applications, but numerous changes in form, usage, and details of implementation can be made without achieving an inventive step and without departing from the principles and concepts of the present invention, as will be apparent to those skilled in the art.

[0078] The following non-limiting examples are for the sole purpose of illustrating the advantages obtained by embodiments of the present invention.

Example

[0079] (Example: Influence of pH and Gas Supply on the Leaching of Black Mass) Black mass containing nickel, cobalt, lithium, manganese, aluminum, and iron in the form of oxides was leached in an aqueous solution at 80 °C for 8 hours. As shown in Table 1 below, seven leaching tests were carried out using the same reactor volume, a leaching solution with a pH level of 0.5 to 3 adjusted using sulfuric acid, and different leaching reagents.

[0080] In one set of tests (L1 - L5), leaching was carried out by oxidizing the metals in the leaching solution with oxygen gas supply (O2), and in another set of tests (L11 and L15), a mixed gas supply of sulfur dioxide (SO2) and air (containing oxygen, O2) was used as a reagent, and leaching was carried out under reducing conditions.

[0081]

Table 1

[0082] The results of these tests show the recovery rates of various metals in the leaching solution after leaching, indicating that excellent metal yields can be achieved by optimizing the pH during the leaching step and selecting the optimal supply of gas reagents.

[0083] As shown by the results in Figure 3, acidic conditions are required to optimize the metal recovery, but Figure 4 shows that all metal recoveries benefit from the use of a reducing gas mixture. Under such reducing conditions, cobalt, nickel, lithium, and manganese can be recovered at a yield of nearly 100% regardless of the pH selection. Aluminum and iron are also strongly affected by the pH even under the reducing conditions.

Industrial Applicability

[0084] The present method and the apparatus suitable for use in the method can be used to replace the conventional alternative means for recovering metals from black mass obtained from lithium-ion batteries.

[0085] In particular, the present method and apparatus provide an economical and efficient procedure for recovering at least one of cobalt, nickel, and lithium, and optionally manganese, from such battery materials in good yields.

Explanation of Signs

[0086] As shown in the figure (see Figures 1 and 2), according to one or more embodiments of the present invention, the following units and inlets can be included in the apparatus of the present invention.

[0087] 1 A pretreatment unit comprising or consisting of the following 11 A washing unit, usually equipped with a solid / liquid separation subunit 12 A heating unit, for example, in the following form 121 A pyrolysis subunit 122 An evaporation subunit 2 A leaching unit, usually equipped with a solid / liquid separation unit, comprising A leaching unit comprising or consisting of the following 21 An acid leaching unit comprising the following 211 Inlets for acid and extractant 212 Temperature adjustment means 3 A metal separation unit comprising the following 31 Option unit for recovering metal materials 32 Unit for separating the initial fraction of metal materials 33 Option unit for recovering manganese 34 Cobalt recovery unit 35 Nickel recovery unit 36 Lithium recovery unit

Claims

1. A method for extracting metals from the black mass of a lithium-ion battery, wherein the black mass contains an anode material and a cathode material of the battery, the cathode material contains lithium, nickel, and cobalt, and the method comprises: (a) one or more pretreatment steps in which a fraction of non-metallic material is separated from the black mass and a pretreated black mass containing the anode material and the cathode material is recovered; (b) one or more leaching steps including an acid leaching step carried out in a solution containing sulfuric acid by further adding a gas containing sulfur dioxide and molecular oxygen as an extractant to the acid leaching step, whereby the cathode material of the pretreated black mass is dissolved and a leaching solution containing the dissolved cathode material is recovered; (c) a metal separation step in which an initial fraction of the metal material is separated from the leaching solution and a major fraction containing at least one of cobalt, nickel, and lithium is recovered; A method for extracting metals from the black mass of a lithium-ion battery, comprising the above steps.

2. The method according to claim 1, which is used for extracting metals from the black mass, and the cathode material contains lithium, nickel, and cobalt in the form of oxides.

3. The method according to claim 1 or 2, wherein the pretreatment step includes one or more steps of washing or heating, or both.

4. The method according to any one of claims 1 to 3, wherein the pretreatment step is carried out to separate non-metallic components from the black mass, and as a result, the pretreated black mass contains less than 3% by weight of organic compounds.

5. The gas containing molecular oxygen used in the leaching step is a gas or gas mixture containing oxygen in the form of O ２ or O ３ The method according to any one of claims 1 to 4, which is a gas or gas mixture containing oxygen in the form of

6. The gas containing sulfur dioxide and molecular oxygen is added at a volume ratio of SO ２ :O ２ adjusted to a level of 0.5:1 to 1.5:1 in the acid leaching step, according to the method of any one of claims 1 to 5. ２ :O ２ ​

7. The method according to any one of claims 1 to 6, wherein the acid leaching is carried out in a single step by dispersing the pretreated black mass in a solution containing both the acid and the extractant.

8. The method according to any one of claims 1 to 7, wherein the acid leaching step is carried out at a temperature above 50°C.

9. The method according to any one of claims 1 to 8, wherein the acid leaching step is carried out at a pressure of 100 - 200 kPa at atmospheric pressure or slightly pressurized.

10. The metal separation step includes one or more steps for recovering a major fraction of a metal material containing at least one of cobalt, nickel, and lithium ions, preceded by one or more steps for separating an initial fraction of the metal material from the leaching solution, according to any one of claims 1 to 9.

11. The metal separation step includes one or more steps for separating an initial fraction of the metal material from the leaching solution, and the initial fraction of the metal material includes at least one of iron, aluminum, calcium, and fluoride ions, according to any one of claims 1 to 10.

12. The metal separation step includes one or more steps for separating an initial fraction of the metal material from the leaching solution, and the step is carried out as solvent extraction aimed at removing impurities from the leaching solution, including at least one step, according to any one of claims 1 to 11.

13. The metal separation step includes one or more steps for separating an initial fraction of the metal material from the leaching solution, and the step is carried out as precipitation aimed at removing impurities and possible phosphates from the leaching solution, including at least one step, according to any one of claims 1 to 12.

14. The metal separation step includes one step for recovering copper from the leaching solution, according to any one of claims 1 to 13.

15. The metal separation step includes a step of recovering at least two of manganese, cobalt, nickel, and lithium ions as a major fraction of the metal material, according to any one of claims 1 to 14.

16. At least lithium and one or more of manganese, cobalt, and nickel ions are recovered in the metal separation step, whereby at least one of the manganese, cobalt, and nickel is recovered before the lithium, according to any one of claims 1 to 15.

17. The metal separation step includes a step of recovering lithium from the leaching solution, according to any one of claims 1 to 16.

18. The method according to any one of claims 1 to 17, wherein cobalt and nickel are recovered from the leaching solution in a simultaneous recovery step or in separate recovery steps.

19. Nickel is recovered from the leach solution by solvent extraction to produce a nickel sulfate solution (NiSO ４ ), the method according to any one of claims 1 to 18.

20. The method according to any one of claims 1 to 19, wherein nickel is recovered from the leaching solution by solvent extraction to produce a nickel sulfate solution, and the solution is used as it is, further purified, or precipitated as a hydroxide or carbonate.

21. The method according to any one of claims 1 to 20, wherein cobalt is recovered from the leaching solution simultaneously with or immediately before the recovery of nickel.

22. Cobalt is recovered from the leaching solution by solvent extraction to produce a cobalt sulfate solution (CoSO ４ ), the method according to any one of claims 1 to 21.

23. The method according to any one of claims 1 to 22, wherein cobalt is recovered from the leaching solution by solvent extraction to produce a cobalt sulfate solution, and the solution is used as it is, further purified, or precipitated as a hydroxide or carbonate.

24. The method according to any one of claims 1 to 23, wherein the metal separation step includes a step of recovering manganese from the leaching solution.

25. An apparatus for extracting metals from the black mass of a lithium-ion battery, wherein the black mass contains the anode material and the cathode material of the battery, the cathode material contains lithium, nickel, and cobalt, and the apparatus includes one or more pretreatment units (1) for separating a fraction of non-metallic components from the black mass and recovering a pretreated black mass containing the anode material and the cathode material; one or more leaching units (2) for dissolving the cathode material of the pretreated black mass and recovering a leaching solution containing the dissolved cathode material, wherein at least one leaching unit (2) is in the form of an acid leaching unit (21) having an inlet (211) for sulfuric acid and an extractant; a metal separation unit (3) for separating metal materials from the leaching solution and recovering a fraction containing at least one of cobalt, nickel, and lithium; and the pretreatment unit (1) includes one or more washing units for mixing the anode material and the cathode material with water or an organic solvent; the apparatus A unit that reacts a spent cleaning solution containing a fraction of the non-metallic material with a phosphate reagent to precipitate lithium in the cleaning solution as lithium phosphate, and a unit that separates the precipitate of lithium phosphate from the remaining cleaning solution and mixes the precipitate with the pretreated black mass conveyed to the leaching unit (2). An apparatus for extracting metals from the black mass of a lithium-ion battery. **Claim 26** The apparatus according to claim 25, wherein the pretreatment unit (1) comprises a cleaning unit (11) and / or a heating unit (12) for removing non-metallic components from the black mass. **Claim 27** The apparatus according to claim 25 or 26, wherein the leaching unit (2) comprises means (212) for adjusting the temperature. **Claim 28** The apparatus according to any one of claims 25 to 27, wherein the metal separation unit (3) comprises one or more units (33, 34, 35, 36) for recovering a major fraction of a metallic material containing at least one of cobalt, nickel, and lithium ions. **Claim 29** A method according to any one of claims 1 to 24, implemented using the apparatus according to any one of claims 25 to 28.

Images