DE102024116277A1 - cementation - Google Patents

Abstract

The invention relates to a method for extracting a metal from a black mass, the method comprising:
a) providing the black mass; and
b) processing the black mass, wherein an acidic leaching agent is used in processing the black mass and wherein a liquid leaching product is obtained, wherein the liquid leaching product contains copper and/or aluminium; and
c) adding an elemental metal to the liquid leach product to precipitate elemental copper to form a copper-containing precipitate and separating the copper-containing precipitate and the liquid leach product; and/or
d) adding an alkaline phosphate to the liquid leach product to precipitate aluminium, thereby forming an aluminium-containing precipitate, and separating the aluminium-containing precipitate and the liquid leach product.

Description

The invention relates to a method for recovering a metal from a black mass and to a recycling product containing a raw material selected from anode material, copper, lithium, nickel, manganese, cobalt, iron and aluminum, wherein the recycling product is obtainable by a method according to the invention.

The relevance of electromobility continues to grow, while ensuring sufficient availability of the required raw materials remains a challenge. Therefore, the recycling of lithium-ion battery cells is becoming increasingly important. Another aspect that is becoming increasingly important, especially from an ecological point of view, is the reduction of chemical use and the minimization of both aqueous and solid waste products.

When lithium-ion battery cells are processed using common methods such as mechanical crushing, thermal treatment or similar processes, what is known as black mass is created. Black mass is typically obtained by crushing the cell and removing components such as electrolyte, binder, conductive foils and housing. Black mass contains significant amounts of anode material, such as graphite, and/or cathode material and thus metals such as lithium, iron, nickel, manganese, cobalt, copper and aluminum, with copper in particular coming from residues of the conductive foils. Recently, cathode material based on lithium iron phosphate (also known as LFP) has become increasingly important in the field of electromobility.

Efficient and clean separation of the components of the black mass is necessary to enable the components to be reused. For example, aluminum and copper can be recovered as raw materials. However, aluminum and copper can also cause disruptions in cleaning processes and contaminate other recoverable materials.

Against this background, one object of the present invention is to provide a method for separating components of the black mass, whereby the separation is as efficient as possible, saves materials and resources and delivers raw materials that are as pure as possible in high yield. The generation of waste should be reduced wherever possible.

1. a) ein Bereitstellen der Schwarzmasse; und
2. b) ein Aufbereiten der Schwarzmasse, wobei beim Aufbereiten der Schwarzmasse ein saures Laugungsmittel verwendet wird und wobei ein flüssiges Laugungsprodukt erhalten wird, wobei das flüssige Laugungsprodukt Kupfer und/oder Aluminium enthält; und
3. c) ein Zugeben eines elementaren Metalls in das flüssige Laugungsprodukt zum Fällen von elementarem Kupfer, wobei ein kupferhaltiger Niederschlag gebildet wird, und Trennen des kupferhaltigen Niederschlags und des flüssigen Laugungsprodukts; und/oder
4. d) ein Zugeben eines alkalischen Phosphats in das flüssige Laugungsprodukt zum Fällen von Aluminium, wobei ein aluminiumhaltiger Niederschlag gebildet wird, und Trennen des aluminiumhaltigen Niederschlags und des flüssigen Laugungsprodukts.

The efforts to solve this problem result in a process for extracting a metal from a black mass, the process comprising:

1. a) providing the black mass; and
2. b) processing the black mass, wherein an acidic leaching agent is used in processing the black mass and wherein a liquid leaching product is obtained, wherein the liquid leaching product contains copper and/or aluminium; and
3. c) adding an elemental metal to the liquid leach product to precipitate elemental copper to form a copper-containing precipitate and separating the copper-containing precipitate and the liquid leach product; and/or
4. d) adding an alkaline phosphate to the liquid leach product to precipitate aluminium, thereby forming an aluminium-containing precipitate, and separating the aluminium-containing precipitate and the liquid leach product.

The term metal includes one or more metals selected from lithium, nickel, manganese, cobalt, iron, copper and aluminum. When the black mass is processed using the acidic leaching agent, metals are dissolved from the black mass, the metals being selected from lithium, iron, nickel, manganese, cobalt, copper and aluminum. The acidic leaching agent is preferably an aqueous sulfuric acid. When the black mass is processed using the acidic leaching agent, a liquid leaching product is obtained which contains metals selected from lithium, iron, nickel, manganese, cobalt, copper and aluminum. Lithium, iron, nickel, manganese and cobalt can be extracted from the liquid leaching product in subsequent steps. It is helpful to first remove copper and aluminum from the liquid leaching product in order to facilitate further processing and to reduce or avoid contamination by copper and aluminum.

The advantage of the invention is that copper and/or aluminum can be removed using simple and inexpensive reagents, so that the subsequent recovery of lithium, nickel, manganese and cobalt can be achieved in better yield and greater purity. Iron, which is a component of lithium iron phosphate cathode material in particular and can be contained in the liquid leaching product, can also be precipitated together with the aluminum and thus recovered, so that the subsequent recovery of lithium, nickel, manganese and cobalt can be achieved in better yield and greater purity. Because the metals used to precipitate copper are used in the process of precipitating the metals, the Since the reagents used to prepare aluminum contain, for example, aluminum, iron and/or phosphate, which are already present in the black mass or at least could be present, additional contamination of the black mass is avoided as far as possible by adding the reagents according to the invention.

The method according to the invention comprises providing a black mass. For this purpose, black mass can be obtained, for example, from lithium-ion battery cells or purchased on the open market. The black mass preferably comes from at least one lithium-ion battery cell. The lithium-ion battery cell is preferably selected from an NMC lithium-ion battery cell and/or an LFP lithium-ion battery cell. The black mass can be obtained when recycling lithium-ion battery cells using common treatment methods. The black mass can be obtained, for example, by crushing lithium-ion battery cells and removing cell components such as electrolyte, binder, current conductor foils and housing. Accordingly, the method for providing black mass can comprise crushing lithium-ion battery cells and/or removing cell components selected from electrolyte, binder, current conductor foils and housing. The black mass preferably contains cathode material, wherein the cathode material is preferably selected from NMC active material (lithium nickel manganese cobalt oxide active material) and LFP active material (LiFePO ₄ active material) and mixtures thereof. The black mass contains metal, wherein the metal comprises one or more metals selected from lithium, nickel, manganese, cobalt, iron, copper and aluminum. The black mass can also contain phosphorus or phosphate, in particular if the black mass contains LFP active material. In a preferred embodiment, the average particle size of the black mass is in the range from 125 µm to 1.5 mm. The black mass can also contain anode material, for example > 20 wt.% anode material, for example graphite-containing anode material or graphite, based on the total weight of the black mass.

In one embodiment, the method according to the invention comprises adding an elemental metal to the liquid leaching product to precipitate elemental copper (step c). In other words, the method according to the invention comprises adding a metal with oxidation state 0. The elemental metal serves as a reducing agent for copper contained in the liquid leaching product. In the process, elemental copper precipitates and a copper-containing precipitate is formed. This step c) can also be referred to as cementation. Cementation is a metallurgical process for depositing a metal from a solution by the action of another, less noble metal. The more noble metal is reduced from the solution and precipitates, while the less noble metal passes into the solution. According to the invention, the elemental metal is preferably selected from elemental aluminum, elemental iron, elemental zinc and mixtures thereof, more preferably from elemental aluminum, elemental iron and mixtures thereof, and particularly preferably comprises aluminum. Preferably, the elemental metal is added in a form selected from powder, dust, chips or mixtures thereof. By using cementation according to the invention, the method according to the invention can be designed to be simple, cost-effective and effective.

In one embodiment, the process according to the invention comprises adding an alkaline phosphate to the liquid leaching product. The alkaline phosphate is preferably a tertiary phosphate, preferably Na ₃ PO ₄ . By adding an alkaline phosphate, aluminum, in particular aluminum phosphate, is precipitated, forming an aluminum-containing precipitate. By adding an alkaline phosphate, iron, in particular iron phosphate, can also be precipitated. By using an alkaline phosphate according to the invention, the process according to the invention can be designed to be simple, inexpensive and effective, and the amount of aqueous waste can be reduced. Tertiary phosphate is preferred because it is strongly basic and therefore small amounts are required. Na ₃ PO ₄ is particularly preferred because sodium can be easily removed and is of little relevance as a contaminant.

The separation of the aluminium-containing precipitate and the liquid leaching product and/or the separation of the copper-containing precipitate and the liquid leaching product can be carried out, for example, by filtration.

The method according to the invention can be part of a method for separating or extracting components from black mass and/or from lithium-ion battery cells.

Embodiments within this document can be combined with one another as desired, provided that the subject matter and the description of the embodiments do not clearly indicate otherwise. The verbs "contain" and "comprise" and their conjugations also include the verb "consist of" and its conjugations. Wei Further preferred embodiments are also specified in the dependent claims.

1. a) ein Bereitstellen der Schwarzmasse; und
2. b) ein Aufbereiten der Schwarzmasse, wobei beim Aufbereiten der Schwarzmasse ein saures Laugungsmittel verwendet wird und wobei ein flüssiges Laugungsprodukt erhalten wird, wobei das flüssige Laugungsprodukt Kupfer und Aluminium enthält; und
3. c) ein Zugeben eines elementaren Metalls in das flüssige Laugungsprodukt aus b) zum Fällen von elementarem Kupfer, wobei ein kupferhaltiger Niederschlag gebildet wird, und Trennen des kupferhaltigen Niederschlags und des flüssigen Laugungsprodukts; und
4. d) ein Zugeben eines alkalischen Phosphats in das flüssige Laugungsprodukt aus c) zum Fällen von Aluminium, wobei ein aluminiumhaltiger Niederschlag gebildet wird, und Trennen des aluminiumhaltigen Niederschlags und des flüssigen Laugungsprodukts.

In a preferred embodiment, the method according to the invention comprises:

1. a) providing the black mass; and
2. (b) processing the black mass, wherein an acidic leaching agent is used in processing the black mass and wherein a liquid leaching product is obtained, wherein the liquid leaching product contains copper and aluminium; and
3. c) adding an elemental metal to the liquid leach product from b) to precipitate elemental copper to form a copper-containing precipitate and separating the copper-containing precipitate and the liquid leach product; and
4. d) adding an alkaline phosphate to the liquid leach product from c) to precipitate aluminium, thereby forming an aluminium-containing precipitate, and separating the aluminium-containing precipitate and the liquid leach product.

An advantage of this embodiment (the combination of precipitating elemental copper by adding an elemental metal, for example elemental iron, elemental aluminum or elemental zinc, and precipitating aluminum by adding an alkaline phosphate) is that metal used as a reducing agent, in particular iron or aluminum, is precipitated by adding alkaline phosphate. Thus, the metal used to precipitate copper, in particular iron or aluminum, is removed from the liquid leaching product and precipitated together with iron and aluminum from the black mass, which facilitates the further recovery of lithium, nickel, manganese and cobalt and allows these elements to be recovered in a purer form.

Preferably, the pH of the liquid leachate for step c) (precipitation of elemental copper) is increased, preferably to a pH between 1.8 and 2.4. Preferably, the pH is increased by adding an alkali metal hydroxide. The increase in pH can take place before or during step c).

It has been found that within the scope of the process according to the invention and especially in combination with the other parameters described herein, copper can be precipitated in this pH range in high yield and purity, i.e. as selectively as possible. By using an alkali metal hydroxide to increase the pH value, product contamination can be reduced or avoided.

Preferably, the pH of the liquid leaching product is increased during step d) (precipitation of aluminum), preferably to a pH between 3.5 and 4.4. The pH is increased by adding the alkaline phosphate. In addition, the pH can be adjusted by adding an alkali metal hydroxide and/or sulfuric acid.

It was found that within the scope of the process according to the invention and especially in combination with the other parameters described herein, aluminum can be precipitated at this pH value in high yield and purity, i.e. as selectively as possible, with iron phosphate also precipitating if necessary. Product contamination can be reduced by using an alkali metal hydroxide and/or sulfuric acid to finely adjust the pH value.

In a preferred embodiment of the process according to the invention, the elemental metal is elemental aluminum or comprises elemental aluminum. Preferably, in step c) for precipitating copper, 0.4 g to 0.7 g of elemental aluminum is added per 1.0 gram of copper in the liquid leaching product.

It has been found that within the scope of the process according to the invention and especially in combination with the other parameters described herein, copper can be precipitated using these parameters in a cost-effective, environmentally friendly manner and in high yield and purity, i.e. as selectively as possible.

Preferably, the alkaline phosphate is added as an aqueous solution, for example as an aqueous solution of 5 wt.% to 15 wt.% Na ₃ PO ₄ , in particular as an aqueous solution of about 10 wt.% Na ₃ PO ₄ .

It has been found that, within the scope of the process according to the invention and especially in combination with the other parameters described herein, aluminum can be precipitated cost-effectively, in an environmentally friendly manner and in high yield and purity, i.e. as selectively as possible. In particular, the base is sufficiently diluted so that no unwanted elements are precipitated, and on the other hand the base is sufficiently concentrated to keep the amounts of aqueous waste low.

Preferably, the alkaline phosphate comprises a tertiary phosphate, preferably Na ₃ PO ₄ . Preferably, for the precipitation of aluminium in step d) add 5 g to 7 g Na ₃ PO ₄ or 13 g to 16 g Na ₃ PO ₄ *12H ₂ O per 1 gram of aluminium.

It has been found that within the scope of the process according to the invention and especially in combination with the other parameters described herein, aluminum can be precipitated using these parameters in a cost-effective, environmentally friendly manner and in high yield and purity, i.e. as selectively as possible.

Preferably, the temperature of the liquid leaching product during the precipitation of elemental copper in step c) is between 25 °C and 60 °C, more preferably between 25 °C and 40 °C.

It has been found that within the framework of the process according to the invention and especially in combination with the other parameters described herein, copper can be precipitated at this temperature in high yield and purity, i.e. as selectively as possible.

Preferably, step c) (precipitation of elemental copper) is carried out over a period of 180 minutes to 360 minutes, more preferably from 180 minutes to 300 minutes. The precipitation of elemental copper in step c) is preferably carried out in a stirred reactor.

It was found that within the framework of the process according to the invention and especially in combination with the other parameters described herein, copper can be precipitated in high yield and purity, i.e. as selectively as possible, within this period.

Preferably, step d) (precipitation of aluminum) is carried out at > 40°C. Preferably, step d) (precipitation of aluminum) is carried out over a period of > 60 minutes. The precipitation of aluminum in step d) is preferably carried out in a stirred reactor.

It has been found that within the scope of the process according to the invention and especially in combination with the other parameters described herein, aluminum can be precipitated under these conditions in high yield and purity, i.e. as selectively as possible.

The separation of the aluminum-containing precipitate and the liquid leaching product is preferably carried out by filtration. In a preferred embodiment, the aluminum-containing precipitate is washed with dilute acid having a pH between 3.5 and 4.4 to obtain a washing solution. In subsequent steps, metals such as lithium, nickel, manganese and cobalt can be recovered from the washing solution.

In a preferred embodiment of the process according to the invention, the process comprises recovering a further metal selected from lithium, nickel, manganese and cobalt from the liquid leaching product from c) or from d), wherein, in order to recover the further metal selected from lithium, nickel, manganese and cobalt, the pH of the liquid leaching product from c) or from d) is adjusted to pH > 9, preferably to pH 10 to pH 11.

By selectively separating copper and aluminum and, if necessary, iron, one or more other metals can be extracted in high purity and yield. By increasing the pH value to > 9, preferably to pH 10 to pH 11, nickel, manganese and cobalt precipitate and can then be separated and extracted. Lithium remains in solution and can be precipitated separately.

double leaching process

• b1) Durchführen eines Flotationsverfahrens mit der Schwarzmasse, wobei ein metallreicher Niederschlag und eine anodenmaterialhaltige Phase erhalten werden und der metallreiche Niederschlag und die anodenmaterialhaltige Phase voneinander getrennt werden;
• b2) Laugen des metallreichen Niederschlags mit dem sauren Laugungsmittel, wobei eine metallhaltige Flüssigkeit und ein anodenmaterialreicher Feststoff erhalten werden;
• b3) Trennen der metallhaltigen Flüssigkeit und des anodenmaterialreichen Feststoffs;
• b4) Laugen der anodenmaterialhaltigen Phase aus b1) mit einem sauren Extraktionsmittel, wobei das saure Extraktionsmittel die metallhaltige Flüssigkeit aus b3) enthält, wobei das flüssige Laugungsprodukt und ein anodenmaterialreicher Feststoff erhalten werden;
• b5) Trennen des flüssigen Laugungsprodukts aus b4) und des anodenmaterialreichen Feststoffs aus b4).

In a preferred embodiment of the method according to the invention, the preparation of the black mass comprises:

• b1) subjecting the black mass to a flotation process to obtain a metal-rich precipitate and a phase containing anode material and separating the metal-rich precipitate and the phase containing anode material;
• (b2) leaching the metal-rich precipitate with the acidic leaching agent to obtain a metal-containing liquid and an anode material-rich solid;
• b3) separating the metal-containing liquid and the anode material-rich solid;
• b4) leaching the anode material-containing phase from b1) with an acidic extractant, wherein the acidic extractant contains the metal-containing liquid from b3), whereby the liquid leaching product and an anode material-rich solid are obtained;
• b5) Separating the liquid leaching product from b4) and the anode material-rich solid from b4).

The processing of the black mass can therefore include a double leaching process.

In this embodiment, the processing of the black mass comprises a double leaching process. In other words, the metal-rich precipitate from b1) is leached (first leaching) and the anode material-containing phase from b1) is leached (second leaching). The process used in b2) for leaching the metal-rich precipitate The acidic leaching agent used is used again for leaching in b4). In other words, the acidic extraction agent consists largely of the metal-containing liquid from b3), whereby the addition of, for example, oxidizing agents, auxiliary materials, etc. for the second leaching should not be excluded. By leaching in b4) (the second leaching), the acidic extraction agent and thus also the metal-containing liquid from b3) are further enriched with metal. At the same time, the anode material in the phase containing the anode material is purified. During the second leaching, the pH value of the acidic extraction agent (containing the metal-containing liquid) increases slightly, so that after completion of the second leaching, copper can be extracted/separated from the liquid leaching product (the metal-rich liquid) from b5) with no or only slight further adjustment of the pH value. The process saves resources and avoids waste. The liquid leaching product can also be referred to as a metal-rich liquid.

The double leaching process can thus be used to obtain a solid rich in anode material from the black mass (in b3) and b5)). The solid rich in anode material can be graphite or a solid rich in graphite. The solid rich in anode material, in particular a solid rich in graphite or graphite, is purified by the process, whereby a quality can be achieved that is suitable for use as a recyclate in batteries or generally in the high-tech industry. The process can therefore be used to obtain a pure solid rich in anode material or a pure solid rich in graphite. The solid rich in anode material from b3) and b5) has an anode material content of between 95% by weight and 99.5% by weight, in particular between 98.0% by weight and 99.5% by weight, based on the total weight of the solid rich in anode material from b3) and b5). In other words, the anode material-rich solid from b3) has an anode material content of between 95 wt.% and 99.5 wt.%, in particular between 98.0 wt.% and 99.5 wt.%, based on the total weight of the anode material-rich solid from b3). In other words, the anode material-rich solid from b5) has an anode material content of between 95 wt.% and 99.5 wt.%, in particular between 98.0 wt.% and 99.5 wt.%, based on the total weight of the anode material-rich solid from b5).

The double leaching process is also gentle, so that the anode material and in particular the graphite retains its morphology. This makes the anode material and in particular the graphite suitable as a recyclate in battery cells or generally in the high-tech industry. The process has the advantage that the morphology of the anode material and in particular the graphite remains essentially unchanged. In particular, graphite retains its spherical shape, its surface structure and its electrochemical properties for use as anode material and for other high-tech applications, e.g. in bipolar plates in electrolysis devices for producing hydrogen.

The double leaching process allows the metallic components to be dissolved from the black mass. The acid solution is enriched with metal and the liquid leaching product (a metal-rich liquid) can be used for the efficient recovery of metal.

The flotation process is particularly effective in extracting the metal-rich precipitate and the anode material-containing phase from the black mass and separating the metal-rich precipitate and the anode material-containing phase. Flotation processes with black mass are known to the expert and are described, for example, by Anna Vanderbruggen et al. in “Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment” (January 2022, Minerals 12 (1 )), which is hereby fully incorporated.

A collector is preferably used in the flotation process. Kerosene is preferably used as a collector. The collector leads to an improved separation of the phase containing the anode material. This increases the yield of recovered anode material and the metal-rich precipitate contains less anode material and is therefore purer. However, the collector also entrains metal from the active material, which is why a gentle and effective subsequent cleaning of the phase containing the anode material and recovery of the metal may be preferable. This cleaning and recovery of the metal can be achieved by the second leaching.

Preferably, a frother is used in the flotation process. Preferably, methylisobutylcarbinol is used as the frother. The frother improves the flotation and contributes to efficient separation.

Preferably, the separation of the metal-containing liquid and the anode material-rich solid in b3) is carried out by filtration.

Preferably, the liquid leaching product from b4) and the anode material-rich solid from b4) in b5) are separated by filtration.

In a preferred embodiment, the liquid leaching product (the metal-rich liquid) from b5) has a pH in the range 0.0 to 1.5. In other words, the second leaching partially neutralizes the metal-containing liquid from b3) and the extremely acidic leaching agent contained therein from the first leaching. The partial neutralization saves chemicals in the further process by saving on reagents for adjusting the pH and reduces the amount of aqueous waste.

The increased pH caused by the second leaching allows the recovery of copper from the liquid leaching product (the metal-rich liquid) from b5) with no or only a slight increase in pH. The recovery of other metals (in particular selected from lithium, nickel, manganese, cobalt, iron and aluminium) is possible after a slight further adjustment of the pH. Since no or only a slight further adjustment of the pH is required, chemicals are saved and the amount of aqueous waste is reduced.

In a preferred embodiment, the acidic leaching agent and the extraction agent contain an oxidizing agent. The oxidizing agent supports the dissolution of the metallic components of the black mass and improves the yield of the process. The oxidizing agent preferably comprises hydrogen peroxide. The concentration of hydrogen peroxide in the acidic leaching agent in b2) and in the extraction agent in b4) is preferably 0.1 vol.% to 10 vol.% based on the total volume of the respective agent.

Preferably, the leaching agent and the extracting agent contain at least one inorganic acid. Preferably, the at least one acid is selected from hydrogen chloride and sulphuric acid, preferably sulphuric acid.

Preferably, the pH of the acidic leaching agent in b2) is ≤0.0. A particularly suitable range for the pH of the acidic leaching agent in b2) is between -1.5 and 0.0.

In one embodiment, the concentration of acid in the acidic leaching agent in b2) is 0.5 mol/L to 4 mol/L.

Preferably, the metal-containing liquid from b3) and the acidic extractant have a pH value <1.0. A particularly suitable range for the pH value of the metal-containing liquid from b3) and the acidic extractant is -0.5 to 0.5.

Preferably, the temperature in b2) (leaching of the metal-rich precipitate) is between 30 °C and 80 °C.

Preferably, the reaction time in b2) (leaching of the metal-rich precipitate) is 60 minutes to 180 minutes.

Preferably, the temperature in b4) (leaching of the phase containing the anode material) is between 30 °C and 60 °C.

Preferably, the reaction time in b4) (leaching of the anode material-containing phase) is 30 minutes to 120 minutes.

Preferably, the ratio (mass to volume) of metal-rich precipitate to acidic leaching agent when leaching the metal-rich precipitate in b2) is 1:5 to 1:15. In other words, 5 liters to 15 liters of acidic leaching agent are used per kilogram of metal-rich precipitate.

Providing the black mass

In one embodiment, the method comprises providing a lithium-ion battery cell and recovering the black mass from the lithium-ion battery cell prior to providing the black mass. Obtaining the black mass comprises comminution of the lithium-ion battery cell. Comminution of the lithium-ion battery cell preferably results in black mass having an average particle size in the range of 125 µm to 1.5 mm.

To remove organic binder and organic electrolyte components, the lithium-ion battery cell and/or the cathode and anode material can be thermally treated at 480 °C - 650 °C, preferably 480 °C - 600 °C.

In one embodiment, the method comprises thermally treating the lithium-ion battery cell and subsequently comminuting the lithium-ion battery cell prior to providing the black mass.

In one embodiment, the method comprises, prior to providing the black mass, comminution of the lithium-ion battery cell under protective gas and subsequent thermal treatment of the components of the comminuted lithium-ion battery cell.

In one embodiment, the method comprises comminuting the lithium-ion battery cell prior to providing the black mass using water (water shredder technology) and subsequent thermal treatment of the components of the shredded lithium-ion battery cell.

In one embodiment, the method comprises removing the current-conducting foils after the thermal treatment. The removal is carried out by common mechanical processing steps such as sieving.

recycled product

The invention also relates to a recycling product containing a raw material selected from anode material, graphite, copper, lithium, nickel, manganese, cobalt, iron and aluminum, wherein the recycling product is obtainable by a process according to the invention.

Due to the process according to the invention, the recycled product has a high degree of purity.

drawings

• 1 ein erfindungsgemäßes Verfahren mit Doppellaugungsverfahren, Zementation und Fällung von Aluminium, insbesondere von Aluminiumphosphat;
• 2 ein erfindungsgemäßes Verfahren mit Zementation und Fällung von Aluminium, insbesondere Aluminiumphosphat;
• 3 ein erfindungsgemäßes Verfahren mit Zementation, aber ohne Fällung von Aluminium, insbesondere Aluminiumphosphat;
• 4 ein erfindungsgemäßes Verfahren mit Fällung von Aluminium, insbesondere Aluminiumphosphat, aber ohne Zementation.

It shows

• 1 a process according to the invention with double leaching, cementation and precipitation of aluminium, in particular aluminium phosphate;
• 2 a process according to the invention with cementation and precipitation of aluminium, in particular aluminium phosphate;
• 3 a process according to the invention with cementation but without precipitation of aluminium, in particular aluminium phosphate;
• 4 a process according to the invention with precipitation of aluminium, in particular aluminium phosphate, but without cementation.

embodiment

The invention is described below using an embodiment with reference to the drawings, in particular 1 , further illustrated.

Exemplary provision of the black mass

First, black mass 10 is obtained from NMC lithium-ion batteries and LFP lithium-ion batteries. The batteries contain graphite as anode material. The lithium-ion batteries are used lithium-ion batteries (also known as end-of-life, EoL) and production waste from lithium-ion battery production. The lithium-ion batteries are deeply discharged and dismantled down to the module or cell level.

The lithium-ion battery cells and lithium-ion battery modules are crushed under nitrogen (N ₂ ) to an average particle size of approx. 150 µm. This is followed by thermal treatment at 480 °C - 600 °C to remove organic binder and electrolyte components. An alternative would be direct thermal pretreatment (also known as pyrolysis) of the battery cells at a temperature between 480 °C - 600 °C and subsequent crushing. Another alternative would be to crush the battery cells using water and then thermally treat the crushed fraction at 480 °C - 600 °C.

After the thermal treatment, the conductive foils and any remaining housing residues are removed by sieving.

What remains is black mass 10.

Exemplary preparation of the black mass 10

The processing of the black mass 10 includes leaching 14 with an acidic leaching agent to obtain liquid leaching product 18.

The following is based on reference to 1 A double leaching process is described for the preparation of the black mass 10. However, it is also possible to digest (prepare) the liquid leaching product 18 by another leaching process, see 2-4 .

In this example of a double leaching process, the black mass 10 is treated by flotation 11, whereby the black mass 10 is placed in water and mixed with additives such as kerosene as a collector and methylisobutylcarbinol as a foaming agent. A foam product containing graphite is then produced using compressed air. With optimized management, a graphite purity of 80% to 90% can be achieved here, with a quality of at least 75% being achieved. The metallic components fall to the bottom during flotation 11 and are called tailings.

The graphite-containing foam product (anode material-containing phase 13) and the tailings (metal-rich precipitate 12) are then leached separately.

First, the tailings fraction (metal-rich precipitate 12) is subjected to leaching with acidic leaching agent 14. Here, a leaching agent with inorganic acid (sulphuric acid or Hydrochloric acid) and a pH value of -1.5 to 0.0. In addition, 35% H ₂ O ₂ is added to the suspension. The hydrogen peroxide makes up 5% by volume of the total solution. The ratio (mass to volume) of metal-rich precipitate 12 to acidic leaching agent is approximately 1:6.

The leaching time in this embodiment is approximately 150 minutes. The temperature in this embodiment is 30 °C to 80 °C. The suspension is constantly stirred. Acid is consumed during the process, so that the pH value remains acidic after completion and is between -0.5 and 0.5.

After the leaching time has elapsed, the suspension is filtered using standard filter technology and separated into solids and liquids enriched with metal ions (metal-containing liquid 15). The solid is an enriched graphite product (anode material-rich solid 16) that is suitable for further processing. The metal-containing liquid 15, which contains metal ions and has an acidic pH value, is used as a leaching agent (acidic extractant) in the leaching 17 of the graphite-containing foam product.

The foam product 13 containing the anode material is mixed with the leaching agent from the first leaching (enriched with metal ions and with an acidic pH value; i.e. the metal-containing liquid 15) and leached. The reduced acid concentration is optimal for treating the enriched graphite fraction gently, which enables the morphology to be preserved. The leaching time is approx. 100 minutes at a temperature of 30 °C to 60 °C. In addition, 35% H ₂ O ₂ is added to the suspension. The hydrogen peroxide makes up approx. 5% by volume of the total solution. The suspension is kept under constant stirring.

After the leaching time has elapsed, the suspension is filtered using standard filter technology and the anode material-rich solid 16 and the liquid, which is even more enriched with metal ions (liquid leaching product 18), are separated. The solid is a graphite product with a purity of ≥ 98.0% (anode material-rich solid 16). The graphite has retained its morphology and is therefore suitable as a recyclate for use in new battery technology. Alternatively, another high-tech industry can be selected. The highly metal-enriched residual leaching solution (liquid leaching product 18) has a pH value between 0.0 and 1.5 after treatment. Other metals, in particular lithium, cobalt, nickel, manganese, aluminum and copper, can be obtained from the highly metal-enriched residual leaching solution (the liquid leaching product 18), whereby according to the invention copper and/or aluminum are first removed.

According to the invention, both the precipitation of copper by cementation 19 and the subsequent precipitation of aluminum 23 by addition of basic phosphate can be carried out on the liquid leaching product 18. However, according to the invention, only the cementation 19 (see 3 ) or only the precipitation of aluminium 23 (see 4 ).

Exemplary cementation 19 for separating copper

In a stirred reactor, cementation 19 is carried out on the highly metal-enriched residual leaching solution (the liquid leaching product 18).

For this purpose, powder of elemental aluminum 20 is added to the liquid leaching product 18 at between 25 °C and 40 °C and the pH is adjusted to approx. 2.0 by adding sodium hydroxide 21. For every 1.0 gram of copper in the liquid leaching product, approx. 0.4 g to 0.7 g of elemental aluminum 20 are added. Elemental copper 22 precipitates and forms a copper-containing precipitate. Aluminum dissolves. The reaction is terminated after approx. 4 hours.

The copper-containing precipitate 22 and the liquid leaching product freed from copper are separated from each other by filtration.

Precipitation of aluminum 23 by addition of alkaline phosphate

The reaction takes place in a stirred reactor. Alkaline phosphate 24 in the form of a 10% aqueous solution of Na ₃ PO ₄ is added to the liquid leaching product 18 or the liquid leaching product freed of copper. Approximately 13 g to 16 g of Na ₃ PO ₄ *12H ₂ O are added per 1 gram of aluminum. This increases the pH to approx. pH 4 and aluminum, particularly aluminum phosphate 25, precipitates, forming an aluminum-containing precipitate. Iron, particularly iron phosphate 26, also precipitates. The pH is controlled by adding an alkali metal hydroxide and/or sulfuric acid.

The aluminium-containing precipitate with aluminium phosphate 25 and the liquid leaching product, which is now free of aluminium and possibly also of copper, are separated by filtration. The aluminium-containing precipitate is washed with dilute acid 27, which preferably has a pH value between 3.5 and 4.4. whereby a washing solution 28 is obtained. Metals such as lithium, nickel, manganese and cobalt can subsequently be recovered from the washing solution 28.

mining of other metals

Metals such as lithium, nickel, manganese and cobalt are subsequently recovered from the liquid leaching product, which has been largely freed of copper and/or aluminum, and the washing solution 28, which is largely free of copper and/or aluminum. To recover the additional metal selected from lithium, nickel, manganese and cobalt, the pH value of the liquid leaching product, which has been largely freed of copper and/or aluminum, is increased to approximately pH 10 to pH 11.

By increasing the pH value to approximately pH 10 to pH 11, precipitation 29 of nickel, manganese and cobalt 30 occurs. Nickel, manganese and cobalt 30 can subsequently be separated and recovered. Lithium 31 remains in solution and can be precipitated separately.

By selectively separating copper, aluminium and, if necessary, iron, one or more other metals can be obtained in high purity and yield.

list of reference symbols

10

black mass

11

flotation process

12

metal-rich precipitation

13

phase containing anode material

14

lye with acidic leaching agent

15

metal-containing liquid

16

Anode material-rich solid

17

alkalis with acidic extractant

18

Liquid leaching product

19

cementation

20

elemental aluminum

21

sodium hydroxide

22

Elemental copper

23

precipitation of aluminum

24

alkaline phosphate

25

aluminum phosphate

26

iron phosphate

27

diluted acid

28

washing solution

29

precipitation of nickel, manganese and cobalt

30

nickel, manganese and cobalt

31

lithium

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited non-patent literature

• by Anna Vanderbruggen et al. in “Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment” (January 2022, Minerals 12 (1 [0042]

Claims (15)

A method of recovering a metal from a black mass, the method comprising: a) providing the black mass; and b) processing the black mass, wherein processing the black mass uses an acidic leaching agent and wherein a liquid leachate is obtained, wherein the liquid leachate contains copper and/or aluminum; and c) adding an elemental metal to the liquid leachate to precipitate elemental copper, thereby forming a copper-containing precipitate, and separating the copper-containing precipitate and the liquid leachate; and/or d) adding an alkaline phosphate to the liquid leachate to precipitate aluminum, thereby forming an aluminum-containing precipitate, and separating the aluminum-containing precipitate and the liquid leachate. Procedure at least after claim 1 , characterized in that the method comprises: a) providing the black mass; and b) processing the black mass, wherein an acidic leaching agent is used in processing the black mass and wherein a liquid leach product is obtained, wherein the liquid leach product contains copper and aluminum; and c) adding an elemental metal to the liquid leach product from b) to precipitate elemental copper, thereby forming a copper-containing precipitate, and separating the copper-containing precipitate and the liquid leach product; and d) adding an alkaline phosphate to the liquid leach product from c) to precipitate aluminum, thereby forming an aluminum-containing precipitate, and separating the aluminum-containing precipitate and the liquid leach product. Process according to at least one of the preceding claims, characterized in that the pH of the liquid leaching product for step c) is increased to between 1.8 and 2.4, preferably by adding an alkali metal hydroxide. Process according to at least one of the preceding claims, characterized in that the pH of the liquid leaching product is adjusted to between 3.5 and 4.4 during step d). Method according to at least one of the preceding claims, characterized in that the elemental metal is selected from elemental aluminum, elemental iron and mixtures thereof, wherein the elemental metal preferably comprises elemental aluminum. Process according to at least one of the preceding claims, characterized in that the elemental metal is aluminum and in step c) for precipitating copper, 0.4 g to 0.7 g of elemental aluminum are added per 1.0 gram of copper in the liquid leaching product. Process according to at least one of the preceding claims, characterized in that the alkaline phosphate is added as an aqueous solution. Process according to at least one of the preceding claims, characterized in that the alkaline phosphate comprises a tertiary phosphate, preferably Na ₃ PO ₄ , preferably wherein 5 g to 7 g Na ₃ PO ₄ or 13 g to 16 g Na ₃ PO ₄ *12H ₂ O are added per 1 gram of aluminum for the precipitation of aluminum in step d). Process according to at least one of the preceding claims, characterized in that the temperature of the liquid leaching product during the precipitation of elemental copper in step c) is between 25 °C and 60 °C, preferably between 25 °C and 40 °C. Method according to at least one of the preceding claims, characterized in that step c) for precipitating elemental copper is carried out over a period of time from 180 minutes to 360 minutes, more preferably from 180 minutes to 300 minutes. Method according to at least one of the preceding claims, characterized in that step d) is carried out at > 40°C and/or over a period of > 60 minutes. Process according to at least one of the preceding claims, characterized in that the precipitation of elemental copper in step c) and/or the precipitation of aluminum in step d) takes place in a stirred reactor. Method according to at least one of the preceding claims, characterized in that the method comprises recovering a further metal selected from lithium, nickel, manganese and cobalt from the liquid leaching product from c) or from d), wherein for recovering the further metal selected from lithium, nickel, manganese and cobalt, an adjustment of the pH value of the liquid leaching product from c) or d) to > 9, preferably to pH 10 to pH 11. Method according to at least one of the preceding claims, characterized in that the processing of the black mass comprises: b1) carrying out a flotation process with the black mass, whereby a metal-rich precipitate and a phase containing anode material are obtained and the metal-rich precipitate and the phase containing anode material are separated from one another; b2) leaching the metal-rich precipitate with the acidic leaching agent, whereby a metal-containing liquid and a solid containing anode material are obtained; b3) separating the metal-containing liquid and the solid containing anode material; b4) leaching the phase containing anode material from b1) with an acidic extractant, whereby the acidic extractant contains the metal-containing liquid from b3), whereby the liquid leaching product and a solid containing anode material are obtained; b5) separating the liquid leaching product from b4) and the solid containing anode material from b4). Recycling product containing a raw material selected from anode material, copper, lithium, nickel, manganese, cobalt, iron and aluminium, wherein the recycling product is produced by a process according to at least one of the Claims 1 - 14 is available.

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