Method and device for producing copper composite material

Abstract

A method and apparatus for producing a copper composite material comprising copper and carbon (e.g., graphite) and having improved processability and / or metal recovery in a method for recycling and / or recovering valuable metals is disclosed. The composite material is a useful intermediate in lithium ion battery recycling.

Description

Technical Field

[0001] A method and apparatus for producing a copper composite material are disclosed, the copper composite material comprising copper and carbon (e.g., graphite), and having improved processability and / or metal recovery rate in a method for recycling and / or recovering valuable metals. The composite material is a useful intermediate in the recycling of lithium-ion batteries. Background Art

[0002] Lithium-ion battery materials are a complex mixture of various elements and compounds. For example, many lithium-ion battery materials contain valuable metals such as lithium, aluminum, copper, nickel, cobalt, and / or manganese. It may be desirable to recover various elements and compounds from lithium-ion battery materials. For example, it may be advantageous to recover lithium, aluminum, copper, nickel, cobalt, and / or manganese. In some battery recycling processes, different process parameters can produce intermediate materials with different compositions and / or properties. Intermediate materials having, for example, advantageous compositions, mechanical properties, surface hydrophilicity, and / or porosity can, for example, have improved processability and / or recovery rate in subsequent downstream processing steps. Such downstream processing steps can be, for example, part of a lithium-ion battery recycling process and / or a more general metal recycling and / or recovery step.

[0003] Therefore, there is a need for materials having improved processability and / or metal recovery rate in subsequent downstream recycling and / or recovery processes. For example, there is a need for intermediate lithium-ion battery recycling materials having, for example, advantageous compositions, mechanical properties, surface hydrophilicity, and / or porosity. In addition, there is a need for improved battery recycling methods for producing such improved intermediate materials. Copper is a very valuable part of waste lithium-ion batteries and thus needs to be recovered during battery recycling.

[0004] EP 3 576 216 A1 discloses a method for recovering valuable materials from lithium-ion batteries, the method comprising a discharging step of discharging the lithium-ion battery; a thermal decomposition step of reducing a lithium compound as a cathode active material to a magnetic oxide by heat-treating the lithium-ion battery after discharging; a crushing step of crushing the lithium-ion battery into fragments of a size suitable for air separation after thermal decomposition, allowing a part of the magnetic oxide to remain in the aluminum foil; a screening step of screening the crushed material to separate the crushed material into an oversized product and an undersized product; an air separation step of separating the oversized product into a heavy product and a light product; and a magnetic separation step of separating and recovering the aluminum foil with magnetic oxide residues as a magnetized material from the light product, and recovering the copper foil as a non-magnetized material from the light product.

[0005] LOMBARDO, Gabriele et al.: “Chemical Transformations in Li-Ion Battery Electrode Materials by Carbothermic Reduction [Chemical Transformations in Li-Ion Battery Electrode Materials by Carbothermic Reduction]”, ACS SUSTAINABLE CHEMISTRY & ENGINEERING [ACS Sustainable Chemistry & Engineering], Vol. 7, No. 16 (2019) pp. 13668-13679, relating to the effect of pyrolysis on the composition of battery cell materials in relation to treatment time and temperature. The waste of Li-ion batteries was pyrolyzed for 30, 60 and 90 min in a nitrogen atmosphere at 400 °C, 500 °C, 600 °C and 700 °C. Treatment of the mixture of the cathode and anode of the NMC Li-ion battery at temperatures between 400 °C and 700 °C triggered carbothermic reduction of the cathode active material and obtained Co, Mn and Ni in lower oxidation states.

[0006] EP 3 702 481 A1 discloses a method for separating copper from an alloy containing copper, nickel and cobalt, which alloy is obtained by dry treatment of waste lithium-ion battery cells. The alloy containing copper, nickel and cobalt is contacted with sulfuric acid in the co-presence of a sulfiding agent, and a solid containing copper and a leachate containing nickel and cobalt are obtained. Summary of the Invention

[0007] Disclosed is a method for producing a copper composite material, which copper composite material contains copper and carbon (such as graphite) and has improved processability and / or metal recovery rate in a method for recycling and / or recovering copper. The method includes heating a lithium-ion battery recycling material to a temperature of 400 °C to 630 °C, while contacting the material with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the material, to obtain a pyrolyzed lithium-ion battery recycling material. The method further includes crushing the lithium-ion battery recycling material before the heating step and / or crushing the pyrolyzed lithium-ion battery recycling material after the heating step, and separating the copper composite material from the crushed and pyrolyzed lithium-ion battery recycling material.

[0008] Also disclosed is a device for producing a copper composite material. The device includes at least two crushing devices, a pyrolysis device and at least one separation device, and the at least one separation device is configured to separate the copper composite material from the crushed and pyrolyzed lithium-ion battery recycling material.

[0009] In addition, the use of the copper composite material in recovering copper from lithium-ion batteries is provided.

[0010] Definitions

[0011] As used herein, the term "composite material" refers to a material that comprises two or more different components.

[0012] As used herein, the term "lithium-ion battery recycling material" refers to a material that comprises a lithium-ion battery or battery waste that contains a copper foil coated with carbon (e.g., graphite coated on the surface of a copper foil).

[0013] The term "pulverizing" is used herein to describe any mechanical treatment of a material in or by any suitable pulverizing device. Examples of suitable pulverizing devices include shredders (such as 4-axis shredders, 2-axis shredders, and 1-axis shredders) and / or mills (such as ball mills, cutting mills, jet mills, and impact mills (especially rotor impact mills)).

[0014] The term "separating device" is used herein to refer to any kind of device suitable for separating battery material particles into different fractions. Examples of suitable separating devices include screening / sieving devices, such as vibrating sieves or drum sieves, zigzag classifiers, separating tables, air jigs, fluidized bed separators, vortex separators, electrostatic separators, magnetic separators, and any combination thereof. Detailed Description

[0015] Copper composite material

[0016] The copper composite material of the present disclosure comprises copper and carbon (e.g., graphite). In some embodiments, the copper composite material comprises 0.1 to 20 wt.-% carbon based on the total weight of the copper composite material. In some embodiments, the copper composite material comprises 0.5 to 15 wt.-%, such as 1 to 5 wt.-%, carbon based on the total weight of the copper composite material.

[0017] In some embodiments, the copper composite material of the present disclosure comprises 80 wt.-% to 99.9 wt.-%, such as 85.0 to 95.5 wt.-%, such as 88.0 wt.-% to 93 wt.-% copper based on the total weight of the copper composite material.

[0018] In some embodiments, the copper composite material of the present disclosure comprises 0.04 wt.-% to 2.0 wt.-%, such as 0.05 to 1.0 wt.-% lithium based on the total weight of the copper composite material.

[0019] In some embodiments, the copper composite material of the present disclosure comprises 0.001 wt.-% to 3.0 wt.-%, such as 0.003 wt.-% to 0.08 wt.-% nickel based on the total weight of the copper composite material.

[0020] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 0.08 wt.-%, such as from 0.002 wt.-% to 0.004 wt.-%, of chromium based on the total weight of the copper composite material.

[0021] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 0.01 wt.-%, such as from 0.001 to 0.006 wt.-%, of iron based on the total weight of the copper composite material.

[0022] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 1.0 wt.-%, such as from 0.03 wt.-% to 0.15 wt.-%, of cobalt based on the total weight of the copper composite material.

[0023] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 0.5 wt.-%, such as from 0.14 wt.-% to 0.25 wt.-%, of manganese based on the total weight of the copper composite material.

[0024] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 2.0 wt.-%, such as from 0.38 wt.-% to 0.75 wt.-%, of aluminum based on the total weight of the copper composite material.

[0025] In some embodiments, the copper composite material of the present disclosure comprises from 0.001 wt.-% to 0.005 wt.-%, such as from 0.001 wt.-% to 0.002 wt.-%, of magnesium based on the total weight of the copper composite material.

[0026] In some embodiments, the copper composite material of the present disclosure takes the form of a plurality of individual particles. In some embodiments, the particle size of the copper composite material measured by sieve analysis according to DIN 66165 is not greater than 500 μm, such as not greater than 250 μm.

[0027] Method for preparing copper composite material

[0028] The present disclosure provides a method for preparing a copper composite material. The method comprises:

[0029] a) providing a lithium-ion battery recycling material, which comprises a copper foil having graphite coated on the surface of the copper foil;

[0030] b) heating the lithium-ion battery recycling material to a temperature of 400 °C to 630 °C while contacting the lithium-ion battery recycling material with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the lithium-ion battery recycling material to obtain a pyrolyzed lithium-ion battery recycling material;

[0031] c) Crushing the lithium-ion battery recycling material before step b) and / or crushing the pyrolyzed lithium-ion battery recycling material after step b) to produce a fine fraction consisting of particles having a particle size of <500 μm;

[0032] d) Separating the copper composite material from the fine fraction of the crushed and pyrolyzed lithium-ion battery recycling material consisting of particles having a particle size of <500 μm.

[0033] The method of the present specification involves heating the lithium-ion battery recycling material to a temperature of 400°C to 630°C while contacting the lithium-ion battery recycling material with an inert gas and with a reducing gas in-situ generated by the thermal decomposition of the lithium-ion battery recycling material.

[0034] In some embodiments, the method of the present disclosure includes providing the lithium-ion battery recycling material at a first temperature; heating the lithium-ion battery recycling material at a second temperature ranging from 400°C to 630°C, such as 520°C to 630°C, such as 550°C to 600°C; contacting the lithium-ion battery recycling material with an inert gas and with a reducing gas in-situ generated by the thermal decomposition of the lithium-ion battery recycling material to obtain a pyrolyzed lithium-ion battery recycling material; and optionally cooling the pyrolyzed lithium-ion battery recycling material to a third temperature ranging from 10°C to 100°C, such as 20°C to 70°C.

[0035] In some embodiments, the method of the present disclosure includes providing the lithium-ion battery recycling material at a first temperature. In some embodiments of the method, the first temperature ranges from -50°C to 50°C, for example, -10°C to 40°C, for example 0°C to 30°C. In a specific embodiment, the first temperature is the ambient temperature.

[0036] In some embodiments, the method of the present disclosure includes heating the lithium-ion battery recycling material at a second temperature ranging from 400°C to 630°C, such as 520°C to 630°C. In some embodiments of the method, the second temperature ranges from 530°C to 600°C. In further embodiments, the second temperature ranges from 550°C to 580°C.

[0037] In some embodiments of the method, the heating step includes a temperature ramp from the first temperature to the second temperature over a period of 10 minutes to 2 hours. In some embodiments of the method, the heating step includes a temperature ramp from the first temperature to the second temperature over a period of 30 minutes to 1 hour.

[0038] In some embodiments, the temperature ramp has an average rate of temperature increase of at least 5 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 10 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 15 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 20 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase of at least 25 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase of up to 50 K / minute.

[0039] In some embodiments, the temperature ramp has an average rate of temperature increase in the range of 5 K / minute to 50 K / minute. In some embodiments, the temperature ramp has an average rate of temperature increase in the range of 10 K / minute to 50 K / minute.

[0040] In some embodiments of the method, the heating step includes a dwell at a second temperature for a period of time in the range of 0 minutes to 1 hour, such as 10 minutes to 45 minutes, or 15 minutes to 30 minutes.

[0041] In some embodiments of the method, the heating step includes a dwell at one or more intermediate temperatures in the range from a first temperature to a second temperature.

[0042] In some embodiments, the method of the present disclosure includes: providing a lithium-ion battery recycling material at a first temperature in the range of -50 °C to 50 °C; heating the lithium-ion battery recycling material at a second temperature in the range of 520 °C to 600 °C; wherein the heating step includes a temperature ramp from the first temperature to the second temperature over a period of time in the range of 10 minutes to 1 hour; a dwell at the second temperature for a time in the range of 0 minutes to 1 hour; and optionally, cooling the material to a third temperature in the range of 50 °C to 70 °C.

[0043] In some embodiments, the method of the present disclosure includes contacting a lithium-ion battery recycling material with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the lithium-ion battery recycling material to obtain a pyrolyzed lithium-ion battery recycling material.

[0044] In some embodiments, the flow rate of the inert gas is in the range of 100 to 300 Sm 3 / h, such as 150 to 250 Sm 3 , such as 200 Sm 3 / h (standard cubic meters per hour).

[0045] In some embodiments, the inert gas comprises at least one gas selected from argon (Ar), nitrogen (N 2 ), helium (He), and mixtures thereof.

[0046] In some embodiments, the reducing gas comprises at least one gas selected from the group consisting of hydrocarbons, hydrogen (H 2 ), carbon monoxide (CO), and mixtures thereof.

[0047] In some embodiments of the method, the reducing gas comprises: 5 vol% to 70 vol% of C 1 to C 10 hydrocarbons, 5 vol% to 95 vol% of carbon dioxide (CO 2 ), 0.1 vol% to 10 vol% of carbon monoxide (CO), and 0.1 vol% to 15 vol% of H 2 ; where each vol% is based on the total volume of the reducing gas, and the vol% of C 1 to C 10 hydrocarbons plus the vol% of CO 2 plus the vol% of H 2 is less than or equal to 100%.

[0048] In some embodiments of the method, the reducing gas comprises: 5 vol% to 70 vol% of C 1 to C 10 hydrocarbons, 5 vol% to 45 vol% of C 1 to C 10 oxohydrocarbons, and 0.1 vol% to 15 vol% of H 2 ; where each vol% is based on the total volume of the reducing gas, and the vol% of C 1 to C 10 hydrocarbons plus the vol% of C 1 to C 10 oxohydrocarbons plus the vol% of H 2 is less than or equal to 100%.

[0049] In some embodiments of the method, the heating step is carried out in a rotary kiln. In some embodiments of the method, the kiln is filled with 5% to 20% of the total volume of the kiln, such as 7% to 16%, such as 9% to 12% of the lithium-ion battery recycling material.

[0050] In some embodiments of the method, at least one screw conveyor is used to feed the lithium-ion battery recycling material into the kiln.

[0051] In some embodiments of the method, the kiln rotates at 0.5 to 3 rpm. In some embodiments of the method, the kiln rotates at 1.4 to 2.6 rpm. In some embodiments of the method, the kiln rotates at 1.8 to 2.2 rpm.

[0052] In some embodiments of the method, an overpressure is maintained in the kiln during operation to prevent air from entering the kiln.

[0053] In some embodiments of the method, hot gas passes through the kiln in the same direction as the process material (cocurrent flow). In some embodiments of the method, the lithium-ion battery recycling material and the inert gas are fed into the rotary kiln in cocurrent flow. The cocurrent flow ensures that no dust escapes from the upper end of the kiln.

[0054] In some embodiments of the method, the rotary kiln is heated by external heating elements using electricity. In some embodiments of the method, the kiln comprises a number of heating zones. In some embodiments of the method, each heating zone operates at a temperature in the range of 520 °C to 600 °C.

[0055] The method of the present disclosure includes at least one step involving comminuting the lithium-ion battery recycling material. In some embodiments, the method includes comminuting the lithium-ion battery recycling material before the heating step. In some embodiments, the method includes comminuting the pyrolyzed lithium-ion battery recycling material after the heating step. In some embodiments, the method includes comminuting the lithium-ion battery recycling material before the heating step and comminuting the pyrolyzed lithium-ion battery recycling material after the heating step.

[0056] In some embodiments of the method, comminuting the lithium-ion battery recycling material or the pyrolyzed lithium-ion battery recycling material comprises the following steps:

[0057] I. Feeding the material into a first comminution device (e.g., a 2-shaft shredder) and comminuting the material, for example, at a tip speed in the range of 0.9 m / s to 1.1 m / s to obtain first particles having a maximum diameter of 50 mm or less;

[0058] II. Feeding the first particles obtained in step I) into a second comminution device (e.g., a single-shaft shredder) and comminuting the first particles, for example, at a tip speed in the range of 3 m / s to 5 m / s to obtain second particles having a maximum diameter of 20 mm or less;

[0059] III. Feeding the second particles obtained in step II) into a first separation device (e.g., a vibrating sieve or a drum sieve) to remove a first fine fraction consisting of particles having a size of <500 μm from the second particles;

[0060] IV. Feeding the second particles obtained in step III) into a third comminution device (e.g., a rotor impact mill) and comminuting the second particles, for example, at a tip speed in the range of 40 m / s to 60 m / s to generate a second fine fraction consisting of particles having a size of <500 μm;

[0061] V. Combining the first fine fraction and the second fine fraction.

[0062] The first and second fine fractions are each composed of particles having a size of <500 μm. In other words, all the particles of the first and second fine fractions will each pass through a sieve having a sieve aperture width of 500 μm.

[0063] In some embodiments, step V involves screening the first and second fine fractions through a sieve having a sieve aperture width of no more than 500 μm (e.g., 250 μm or less). In some embodiments, the particles remaining on the sieve are washed with water to remove the residual fine fractions adhering to the particles remaining on the sieve.

[0064] In some embodiments, separating the copper composite material from the shredded and pyrolyzed lithium-ion battery recycling material involves feeding the pyrolyzed lithium-ion battery recycling material into a separation device that is suitable for separating a mixture of particles into different fractions that exhibit differences in at least one physical property (e.g., having different densities, different wettabilities, or different magnetic properties). Examples of suitable separation devices include zigzag classifiers, shaking tables, air jigs, fluidized bed separators, vortex separators, electrostatic separators, magnetic separators, and any combination thereof.

[0065] In some embodiments, the shredding device and the separation device used in this method are explosion-proof. In some embodiments, the shredding device and the separation device used in this method operate under a nitrogen blanket. Due to the concentration of graphite in the dry anode waste, it is necessary to prevent dust explosions in this method.

[0066] Lithium-ion battery recycling material

[0067] Lithium-ion batteries can be disassembled, punched, milled (e.g., in a hammer mill, rotor mill), and / or shredded (e.g., in an industrial shredder). The active materials of the battery electrodes can be obtained through such mechanical processing. Light fractions (such as the housing parts made of organic plastics and aluminum foil or copper foil) can be removed, for example, by forced air flow, air separation, classification, or screening.

[0068] Lithium-ion batteries including wet battery cells need to be fully discharged before shredding them, otherwise there is a risk of fire inside the shredder. The further deactivation of wet battery cells is affected by the removal of highly flammable solvents and the oxidation of highly reactive Li present in the anode.

[0069] Battery waste can originate from, for example, waste batteries or production waste such as defective materials. In some embodiments, the material is obtained from mechanically processed battery waste, for example, from battery waste processed in a hammer mill, rotor mill, or industrial shredder.

[0070] A relatively large portion of battery waste (such as the housing, wiring, and electrode carrier film) can be mechanically separated so that the corresponding materials can be excluded from the battery materials used in the disclosed method. In some embodiments, the separation is accomplished by manual or automated sorting. For example, magnetic fractions can be separated via a vortex separator by magnetic separation of non-magnetic metals. Other techniques can include jigs and air tables.

[0071] In some embodiments, the lithium-ion battery recycling material contains nickel, cobalt, manganese, copper, aluminum, iron, phosphorus, or a combination thereof.

[0072] In some embodiments of the method, the provided lithium-ion battery recycling material contains copper foil and carbon (e.g., graphite coated thereon) and is obtained by a method including: shredding the battery material and drying the shredded battery material.

[0073] In some embodiments, the method for recycling lithium-ion battery materials includes mechanically pulverizing at least one selected from lithium-ion batteries, lithium-ion battery waste, lithium-ion battery production waste, lithium-ion battery cell production waste, lithium-ion cathode active materials, and combinations thereof.

[0074] In some embodiments, the lithium-ion battery recycling material contains 1 wt.-% to 11 wt.-% of copper, such as 2 to 10 wt.-% of copper, such as 4 to 8 wt.-% of copper in the form of copper foil in the zero oxidation state, and 5 wt.-% to 32 wt.-% of carbon, such as 13 to 29 wt.-% of carbon, such as 22 to 26 wt.-% of carbon; where each wt.-% is based on the total weight of the lithium-ion battery recycling material.

[0075] Copper composite material production equipment

[0076] The present disclosure also provides an apparatus for producing a copper composite material. The apparatus includes at least two pulverizing devices, a pyrolysis device, and at least one separation device configured to separate the copper composite material from the pulverized and pyrolyzed lithium-ion battery recycling material.

[0077] In some embodiments, the at least two pulverizing devices include a combination of a first pulverizing device (e.g., a 2-shaft shredder) and a second pulverizing device (e.g., a single-shaft shredder) disposed downstream of the first pulverizing device. In some embodiments, the at least two pulverizing devices further include a third pulverizing device (e.g., a rotor impact mill) disposed downstream of the second pulverizing device.

[0078] In some embodiments, the first comminution device is configured to operate at a tip speed in the range of 0.9 m / s to 1.1 m / s. In some embodiments, the first comminution device is configured to produce particles having a maximum diameter of 50 mm or less.

[0079] In some embodiments, the second comminution device is configured to operate at a tip speed in the range of 3 m / s to 5 m / s. In some embodiments, the second comminution device is configured to produce particles having a maximum diameter of 20 mm or less.

[0080] In some embodiments, the third comminution device is configured to operate at a tip speed in the range of 40 m / s to 60 m / s. In some embodiments, the first comminution device is configured to produce particles having a maximum diameter of 500 μm or less.

[0081] The maximum particle size can be easily determined using a perforated plate or sieve having an appropriate hole size or mesh width, such as a perforated plate with holes of 50 mm diameter, a perforated plate with holes of 20 mm diameter, and a sieve with a mesh size of 500 μm. All particles must pass through the corresponding perforated plate or sieve.

[0082] The apparatus for producing a copper composite material according to the present disclosure includes a pyrolysis device that heats a lithium-ion battery recycling material to a temperature in the range of 400 °C to 630 °C while bringing the lithium-ion battery recycling material into contact with an inert gas and a reducing gas in-situ generated by the thermal decomposition of the lithium-ion battery recycling material. In some embodiments, the pyrolysis device includes a supply line for supplying an inert gas and / or a reducing gas to the pyrolysis space of the pyrolysis device. In some embodiments, the pyrolysis device includes an oven, such as an electric oven.

[0083] In some embodiments, the pyrolysis device includes a rotary kiln. The rotary kiln is a cylindrical tube that is slightly inclined with respect to the horizontal plane and slowly rotates about its longitudinal axis. The process raw material is fed into the upper end of the cylinder. As the kiln rotates, the material gradually moves downward towards the lower end and may undergo a certain degree of agitation and mixing.

[0084] In some embodiments, the kiln has a length in the range of 12 to 18 m. In some embodiments, the kiln has a length in the range of 15 to 17 m. The kiln length refers to the length of the heating zone of the kiln. Additional elements will make the entire kiln slightly longer. In some embodiments, the inner diameter of the cylindrical tube is in the range of 1.5 m to 2.2 m, such as 1.7 m to 1.9 m.

[0085] In some embodiments, the rotary kiln is characterized by an external heating element that uses electricity. In some embodiments, the kiln includes a number of heating zones. In some embodiments, each heating zone is configured to operate at a temperature in the range of 400 °C to 650 °C, such as 520 °C to 600 °C. In some embodiments, a thermoelectric element is provided in each heating zone for measuring the temperature in the corresponding zone. In one embodiment, each heating zone has a length of 0.5 m to 6 m, such as 1 m to 4 m, such as 1.5 m to 3 m.

[0086] In some embodiments, the kiln is connected at its lower end with a material discharge hood and a conduit for the exhaust gases, and is characterized by being hermetically sealed at both ends of the kiln. Installation equipment is provided to eliminate hydrocarbons from the exhaust gas stream of the kiln before venting the exhaust into the atmosphere.

[0087] Uses of copper composite material

[0088] This disclosure also provides the use of the composite material in the recovery of copper from lithium-ion batteries. Due to the high copper content of the copper composite material of this disclosure, it can be directly used in the production of copper anodes for the electrolytic refining (electrolytic deposition) of copper. Due to its residual carbon content, the copper composite material of this disclosure can be advantageously used in a smelting reduction process, such as in an electric oven.

[0089] Examples

[0090] Elemental analysis

[0091] This section describes an analytical method for quantitatively determining the composition of the copper composite material of this disclosure.

[0092] Metal content

[0093] Elemental analysis is carried out using a combination of acid digestion and alkaline borate fusion digestion and analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) on an inductively coupled plasma optical emission spectrometer (e.g., Agilent 5110 ICP-OES, Agilent Technologies Germany GmbH&Co.KG, Waldbronn 76337, Germany).

[0094] An aliquot (e.g., about 0.2 g) of the sample material is weighed into a volumetric flask and dissolved in 30 ml of HCl with gentle heating. After cooling, the insoluble residue is filtered out and incinerated in a Pt crucible above an open flame together with the filter paper. Subsequently, the residue is calcined in a muffle furnace at about 600 °C and then combined with 1.0 g of K 2 CO 3 -Na 2 CO 3 / Na 2 B 4 O 7 The flux mixture (4:1) was mixed and melted over an open flame until a clear melt was obtained. After cooling, the melt cake was dissolved in deionized (DI) water under gentle heating, and 12 ml of HCl was added. Finally, this solution was added to the initial filtered solution in a volumetric flask and made up to its final volume with DI water. Each sample was prepared in triplicate. A blank sample was prepared in a similar manner.

[0095] The digestion solution was analyzed by using externally calibrated inductively coupled plasma - optical emission spectrometry (ICP - OES). For some samples, the digestion solution could be diluted before analysis, for example, diluted to suit the concentration and calibration range of the corresponding analyte.

[0096] Carbon content

[0097] The carbon content was determined by performing elemental analysis in an automatic analyzer (vario EL Cube, Elementar Analysensysteme GmbH, Langenselbold, Germany 63505). The sample (2 - 3 mg) was weighed into a tin capsule. Using copper oxide as a combustion catalyst, the capsule with the sample was burned in a helium / oxygen atmosphere at approximately 1100 °C. After separating the combustion gases by chromatography, the carbon was determined as CO 2 and detected and quantified by measuring the thermal conductivity using a TCD.

[0098] Examples

[0099] The intermediate lithium - ion battery recycling material containing the cathode active material was fed into a 2 - axis shredder and shredded at a tip speed of 1 m / s to obtain first particles with a maximum diameter of 50 mm or less. The obtained first particles were fed into a single - axis grinder and shredded at a tip speed of 4 m / s to obtain second particles with a maximum diameter of 20 mm or less. The first fine fraction with a particle size of <500 μm was separated from the second particles in a vibrating sieve. Subsequently, the second particles were fed into a rotor impact mill and shredded at a tip speed of 50 m / s to generate a second fine fraction with a particle size of <500 μm. The first fine fraction and the second fine fraction were combined to obtain the shredded lithium - ion battery recycling material.

[0100] Feed the shredded lithium-ion battery recycling material into a rotary kiln. The temperature in the rotary kiln ramps up from room temperature to 540 °C over a 50-minute period. The shredded lithium-ion battery recycling material is held at 540 °C for 10 minutes. Contact the material with an inert gas and a reducing gas in-situ generated by the thermal decomposition of the shredded lithium-ion battery recycling material to obtain a shredded and pyrolyzed lithium-ion battery recycling material containing the copper composite material disclosed herein.

[0101] Separate the copper composite material from the shredded and pyrolyzed lithium-ion battery recycling material using a wind jigger. Conduct elemental analysis on the obtained copper composite material. Perform the determination in triplicate for each element. The composition of the copper composite material is given as follows:

[0102]

[0103] The copper composite material has a particle size of <500 μm and is suitable for producing copper anodes through a reduction smelting process in an electric oven.

Claims

1. A method for preparing a copper composite material, the method comprising a) providing a lithium-ion battery recycling material comprising a copper foil having graphite coated on the surface thereof; b) heating the lithium-ion battery recycling material to a temperature of 400 °C to 630 °C while contacting the lithium-ion battery recycling material with an inert gas and with a reducing gas in-situ generated by thermal decomposition of the lithium-ion battery recycling material to obtain a pyrolyzed lithium-ion battery recycling material; c) pulverizing the lithium-ion battery recycling material before step b) and / or pulverizing the pyrolyzed lithium-ion battery recycling material after step b) to produce a fine fraction consisting of particles having a particle size of <500 μm; d) separating the copper composite material from the pulverized and pyrolyzed lithium-ion battery recycling material fine fraction consisting of particles having a particle size of <500 μm.

2. The method according to claim 1, wherein step c) comprises the following steps: I. feeding the material to a first pulverizing device and pulverizing the material to obtain first particles having a maximum diameter of 50 mm or less; II. feeding the first particles obtained in step I) to a second pulverizing device and pulverizing the first particles to obtain second particles having a maximum diameter of 20 mm or less; III. feeding the second particles obtained in step II) to a first separating device to remove a first fine fraction consisting of particles having a size of <500 μm from the second particles; IV. feeding the second particles obtained in step III) to a third pulverizing device and pulverizing the second particles to produce a second fine fraction consisting of particles having a size of <500 μm; V. combining the first fine fraction and the second fine fraction.

3. The method according to claim 1 or 2, wherein step d) involves separating the copper composite material from the pulverized and pyrolyzed lithium-ion battery recycling material fine fraction consisting of particles having a particle size of <500 μm based on density differences.

4. The method according to any one of claims 1 to 3, wherein the lithium-ion battery material comprises at least one selected from the group consisting of lithium-ion batteries, lithium-ion battery waste, lithium-ion battery production waste, lithium-ion battery cell production waste, lithium-ion cathode active materials, and combinations thereof.

5. The method according to any one of claims 1 to 4, wherein the lithium-ion battery recycling material contains nickel, cobalt, manganese, copper, aluminum, iron, phosphorus, or a combination thereof.

6. The method according to any one of claims 1 to 5, wherein the lithium-ion battery recycling material contains 1 wt.-% to 11 wt.-% of copper in the form of a copper foil in the zero oxidation state and 5 wt.-% to 32 wt.-% of carbon; where each wt.-% is based on the total weight of the lithium-ion battery recycling material.

7. The method according to any one of claims 1 to 6, wherein the copper composite material contains 80 wt.-% to 99.9 wt.-% of copper and 0.1 wt.-% to 20 wt.-% of carbon based on the total weight of the copper composite material.

8. The method according to any one of claims 1 to 6, Among them, the copper composite material contains 0.04 wt.-% to 1.0 wt.-% of lithium, and / or 0.001 wt.-% to 0.08 wt.-% of nickel, and / or 0.001 wt.-% to 0.08 wt.-% of chromium, and / or 0.001 wt.-% to 0.15 wt.-% of cobalt, and / or 0.001 wt.-% to 0.006 wt.-% of iron, and / or 0.001 wt.-% to 0.25 wt.-% of manganese, and / or 0.001 wt.-% to 0.75 wt.-% of aluminum, and / or 0.001 wt.-% to 0.002 wt.-% of magnesium, based on the total weight of the copper composite material.

9. An apparatus for producing a copper composite material as claimed in any one of claims 1 to 8, the apparatus comprising at least two comminution devices, a pyrolysis device, and at least one separation device, the at least one separation device being configured to separate the copper composite material from shredded and pyrolyzed lithium-ion battery recycling material having a particle size of <500 μm.

10. The apparatus according to claim 9, wherein, the at least two comminution devices comprise a combination of a 2-axis shredder and a single-axis shredder arranged downstream of the 2-axis shredder.

11. The apparatus according to claim 10, which further comprises a rotor impact mill arranged downstream of the 2-axis shredder.

12. The apparatus according to any one of claims 9 to 11, wherein, the pyrolysis device comprises a rotary kiln.

13. The apparatus according to claim 12, wherein, the rotary kiln is characterized by an external heating element using electricity.

14. The apparatus according to any one of claims 9 to 13, wherein, the separation device comprises a zigzag classifier, a shaking table separator, a wind jigger, a fluidized bed separator, a vortex separator, or a combination thereof.

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