A method for regenerating lithium battery waste

Abstract

The invention discloses a regeneration method for lithium battery waste, belongs to the technical field of waste battery regeneration, and mainly relates to a hydrogen reduction roasting method for lithium battery waste, including three-stage reduction roasting; the temperature of the first stage reduction roasting is 450±20℃, the hydrogen flow rate is 10‑15m 3 / h tons of material, the reduction roasting time is 10-20min, the second stage reduction roasting temperature is 530±40℃, and the hydrogen flow rate is 20-30m 3 / h tons of material, the reduction roasting time is 10-40min, the temperature of the third stage reduction roasting is 620±30℃, and the hydrogen flow rate is 25-30m 3 / h tons of material, and the reduction roasting time is 10-30min. After the roasting product is leached, the leachate is further treated to remove impurities and precipitate lithium to prepare a lithium salt product, and the leached residue is subsequently treated to separate and recover nickel and / or cobalt and manganese. The method of the present invention can achieve simple and efficient separation of valuable elements in lithium battery waste.

Description

Technical Field

[0001] The invention belongs to the technical field of recycling waste batteries, and in particular relates to a method for recycling waste lithium batteries. Background Art

[0002] Lithium battery recycling is the top priority of the lithium battery industry cycle. In the recycling process of ternary lithium-ion batteries (NCM, NCA, etc.), since low-valent metal ions are more easily leached, transition metals must first be reduced from a high-valent state to a low-valent state. The current main reduction methods are reduction leaching and solid-phase reduction. The use of wet reducing agents in the reduction leaching process poses wastewater treatment pressure, and solid-phase roasting is easier to implement industrially. Therefore, a solid-phase reduction roasting process is proposed.

[0003] During the solid-phase reduction roasting process, the high-valent nickel, cobalt and manganese metal compounds in the cathode material are reduced to low-valent oxides or metal elements, and then leached out by acid. Solid-phase reduction roasting mainly includes carbon thermal reduction and hydrogen reduction. The former inevitably faces the problem of lithium recovery being neglected or the lithium recovery rate being low. This possible lithium resource shortage crisis can only be avoided when more than 90% of the lithium in waste lithium-ion batteries is recovered. In addition, the carbon thermal reduction roasting process inevitably produces carbon dioxide, which is also contrary to the era background of "carbon integration".

[0004] Therefore, it is necessary to develop a waste battery recycling process that can effectively recycle valuable metals such as cobalt, nickel, and manganese, and can efficiently recycle lithium resources. While pursuing the efficient recovery of valuable metals such as cobalt, nickel, and manganese, lithium can also be effectively extracted. The hydrogen reduction roasting-water leaching process was proposed.

[0005] CN202210814348.9 discloses a method for recycling lithium sulfate, lithium carbonate and lithium hydroxide from ternary lithium batteries, which mixes black powder with sulfuric acid, performs reduction roasting in a high-purity hydrogen atmosphere, and extracts lithium by water leaching of the roasting product, while nickel, cobalt and manganese remain in the slag for subsequent treatment and recovery. However, this process not only requires carbon powder to participate in the reduction reaction, but also 5% of nickel, cobalt and manganese enter the solution in the form of its salt. Therefore, in the subsequent lithium salt preparation process, it is necessary to add additional precipitation impurity removal-UF membrane filtration-anion exchange unit-multi-stage electrodialysis extreme desalination-chelating resin unit and other nickel, cobalt and manganese impurity removal processes to obtain a refined lithium extraction solution that meets the requirements. Although its full-process lithium recovery rate can reach more than 99.9%, and battery-grade lithium salt products can be produced, the use of multiple high-requirement, high-investment and high-operation requirements purification processes makes its overall process complex, difficult to operate, and has a large flow of intermediate materials. And the wastewater treatment is difficult, and there are inevitably many difficulties in the process of industrial application, and it can be expected that the smoothness of production operation is difficult to guarantee.

[0006] CN202210744766.5 discloses a method for recovering positive and negative electrode materials of ternary lithium batteries, which mixes the positive and negative electrode powders of ternary lithium batteries with a reducing agent and an acidulant, and then roasts them in a plasma path with a reducing atmosphere containing hydrogen, and the roasted product is leached with lithium manganese, and the leached solution is precipitated to remove manganese and then carbonized to precipitate lithium to obtain lithium carbonate, while nickel, cobalt and aluminum are prepared into cobalt-doped nickel-based catalysts. Although the process flow of this patent is short, it does not reveal the recovery rate of lithium, the purity and performance of lithium products and catalyst products, and the process effect is difficult to determine; in addition, manganese and lithium enter the solution at the same time, and a large amount of manganese is inevitably caused by the entrainment loss of lithium, and the purity of the lithium solution after manganese removal is difficult to guarantee, and the industrial practicality is not high.

[0007] CN202010336862.7 discloses a method for extracting lithium from lithium battery waste at the front end, which first uses a thermal reduction method to cooperate with a decomposition agent to destroy the structure of the positive electrode material, so that lithium exists in the form of a small molecule lithium compound, and elements such as nickel, cobalt, and manganese exist in the form of low-valent oxides; in the cold quenching process and the activation process, the material specific surface area is further increased to increase its activity, and the lithium element is converted into lithium hydroxide with great solubility through oxygen pressure / normal pressure leaching to enter the solution, thereby achieving the purpose of efficient extraction of lithium. Although this method can fully destroy the spatial structure of lithium combined with nickel, cobalt, and manganese materials, so that the lithium element is completely released, in addition to still using conventional carbonaceous reducing agents as solid reducing agents, the entire process needs to rely on high temperature and high pressure, protective atmosphere cold quenching, secondary ball milling activation and other means, and the industrialization requirements are high and the operation and control are difficult.

[0008] In order to overcome the above-mentioned defects of the existing hydrogen reduction process, the applicant proposed a combined recovery method of ternary materials in the preliminary research (CN202311731431.0), which uses a roasting-water immersion fire method wet method combined treatment process to recover the waste ternary materials in a short process. Although this method solves the drawbacks of the existing hydrogen reduction recovery technology to a certain extent, it relies on specific deoxidizing agents, which is not only complicated to operate, but also adds additional preparation processes. There is still room for further optimization in terms of process flow and lithium recovery rate.

[0009] Therefore, how to efficiently, easily industrialize and operate the hydrogen reduction of ternary lithium-ion batteries, reduce the dependence on carbonaceous reducing agents, and fully reduce nickel, cobalt and manganese to low-valent states, especially elemental states, to achieve crystal structure collapse and control the reduction process, so that Li can be fully released from the crystal structure, and then achieve full leaching of lithium and efficient selective separation from nickel, cobalt and manganese, fundamentally avoid the complication of the separation process, and at the same time ensure a high metal recovery rate, and ultimately achieve efficient circulation of valuable resources is a difficulty that needs to be overcome. Summary of the invention

[0010] The object of the present invention is to provide a method for regenerating lithium battery waste to solve at least one aspect of the problems and defects raised in the above background technology.

[0011] A method for regenerating lithium battery waste, characterized in that it comprises the following steps:

[0012] Placing lithium battery waste powder in a roasting furnace, introducing hydrogen-containing gas for reduction roasting to obtain a reduction roasting product, wherein the reduction includes one-stage reduction roasting, two-stage reduction roasting and three-stage reduction roasting;

[0013] The first stage reduction roasting temperature is 450±20℃, and the hydrogen flow rate in the hydrogen-containing gas is 10-15m 3 / h tons of material, reduction roasting time is 10-20min;

[0014] The second stage reduction roasting temperature is 530±40℃, and the hydrogen flow rate in the hydrogen-containing gas is 20-30m 3 / h tons of material, the reduction roasting time is 20-40min;

[0015] The temperature of the three-stage reduction roasting is 620±30℃, and the hydrogen flow rate of the hydrogen-containing gas is 25-30m 3 / h tons of material, the reduction roasting time is 10-30min.

[0016] Furthermore, the temperature of the first stage reduction roasting is 450±15°C, and the hydrogen flow rate of the hydrogen-containing gas is 12-15m 3 / h tons of material, the reduction roasting time is 11-15min;

[0017] The temperature of the second stage reduction roasting is 530±30℃, and the hydrogen flow rate of the hydrogen-containing gas is 20-30m 3 / h tons of material, reduction roasting time is 25-35min;

[0018] The temperature of the three-stage reduction roasting is 620±20℃, and the hydrogen flow rate of the hydrogen-containing gas is 25-30m 3 / h tons of material, the reduction roasting time is 15-25min.

[0019] Furthermore, the calcination process is enhanced by applying an external field, wherein the external field includes a magnetic field and / or a microwave field.

[0020] Furthermore, the external field is a uniform magnetic field and / or a microwave field, wherein the magnetic field intensity is 100-600 mT and the microwave power is 1.0-5.0 kW.

[0021] Furthermore, the external field is a variable magnetic field and / or a variable microwave field, wherein the magnetic field strengths of the first, second and third stages of reduction roasting are 400-600mT, 300-500mT, 500-700mT, respectively, and the microwave powers are 1.0-1.5kW, 1.8-2.5kW, 3.0-5.0kW, respectively.

[0022] Furthermore, the magnetic field intensities of the first, second and third stage reduction roasting are 450-600mT, 300-450mT and 550-650mT respectively, and the microwave powers are 1.2-1.5kW, 2.0-2.5kW and 3.5-5.0kW respectively.

[0023] Furthermore, a magnetic field with an intensity of 100-600 mT is applied during the second-stage reduction roasting and / or a microwave field with a power of 1.0-5.0 kW is applied during the third-stage reduction roasting.

[0024] Furthermore, the lithium battery waste contains at least one of nickel, cobalt, and manganese; and / or the lithium battery waste powder includes waste powder that has been or has not been pretreated, and the pretreatment includes oxidation treatment; the oxidation treatment includes oxidative roasting, the roasting temperature is 450-600°C, and the roasting time is 0.5-2h.

[0025] Furthermore, the hydrogen-containing gas is hydrogen or a mixture of hydrogen and an inert gas, the hydrogen concentration in the hydrogen-containing gas is 50v%-100v%, and the inert gas is nitrogen and / or helium.

[0026] Furthermore, it also includes a reducing product leaching step, wherein the pH value of the reducing product leaching solution is 7±0.5, the solid-liquid ratio is 1:5-20, the leaching temperature is 10-100°C, and the leaching time is 0.5-2h.

[0027] Furthermore, the leachate can be subjected to impurity removal and lithium precipitation to prepare lithium salt products, and the leached residue can be subsequently separated and recovered from nickel, cobalt and / or manganese and / or aluminum.

[0028] The lithium content in the lithium ion battery waste of the present invention is ≥3.50% (mass percentage, the same below), and / or nickel ≥3.0%, and / or cobalt ≥3%, and / or manganese ≥3.0%, and / or aluminum content ≥0.2%. The lithium battery waste powder includes positive electrode powder, positive and negative electrode mixed powder, mixed powder of two or more battery wastes, etc. The lithium battery material includes lithium nickel cobalt manganese oxide, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium nickel manganese oxide, nickel cobalt aluminum oxide, etc.

[0029] Beneficial Effects

[0030] This application conducts an in-depth study on the hydrogen reduction roasting process, analyzes the hydrogen reduction reaction process from the microscopic reaction level, explores the characteristics of the hydrogen reduction process stages and proposes a targeted stage-controlled parameter roasting process, thereby obtaining the process of the present invention.

[0031] The present invention adopts staged heating and roasting in a hydrogen-containing gas atmosphere, and controls parameters such as the roasting temperature, hydrogen flow rate, and roasting time in each stage and the coordination between the parameters, preferably using microwave and / or magnetic field to strengthen the control of the coordinated reduction roasting parameters, so as to achieve precise control of the hydrogen reduction process of the waste lithium ion battery, thereby achieving controlled and efficient selective reduction of high-valent compounds in the waste lithium ion battery, while achieving full conversion and release of lithium ions, thereby achieving full separation from lithium elements, significantly improving the selective leaching effect of lithium, and finally achieving efficient and selective leaching of lithium ions, effectively improving the lithium recovery rate while significantly shortening the roasting time and reducing the roasting temperature, effectively saving energy and reducing consumption, and laying a solid foundation for simplification of the roasting process of waste lithium battery materials and post-process separation and purification.

[0032] Through the process of the present invention, lithium, nickel, cobalt and / or manganese in waste lithium-ion batteries are efficiently, controllably and fully reduced, and the reaction temperature is low, the time is short, and the strengthening means are easy to implement and control. Neutral leaching is combined to effectively ensure that non-lithium elements are fully retained in the slag phase, greatly simplifying the subsequent wet impurity separation process, avoiding the use of expensive reagents while reducing the amount of various reagents and the resulting wet impurity removal and three waste treatment problems, fundamentally saving energy, reducing emissions and increasing efficiency, and having outstanding industrial advantages. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0034] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] The mass fraction of lithium in the following embodiments and comparative examples of lithium-ion battery waste is 4.89%, the mass fraction of nickel is 33.27%, the mass fraction of manganese is 3.86%, the mass fraction of cobalt is 4.20%, and the mass fraction of aluminum is 1.31%.

[0036] Example 1

[0037] The battery waste powder was placed in a roasting furnace, and hydrogen was introduced to exhaust the tail gas in the kiln. The hydrogen introduction was stopped, and the roasting furnace was started to heat up (the heating rate was selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge was controlled to be ≤10°C, the same below). After the temperature was raised to 430°C, microwaves were applied and hydrogen was introduced for roasting for 15 minutes, wherein the microwave power was 1.1kW and the hydrogen flow rate was 10m 3 / h tons of material, and then the temperature was raised to 500℃, the microwave power was adjusted to 2.0kW, the hydrogen flow rate was 20m 3 / h tons of material, roast for 30 minutes, then heat to 610℃, adjust the microwave power to 5.0kW, and the hydrogen flow rate to 25m 3 / h tons of material, after roasting for 15 minutes, stop applying microwaves and gas introduction, cool to below 100°C under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:10 g / mL, react at 25°C for 1.5 hours, and separate the solid and liquid to obtain leaching residue and leaching phase. The lithium leaching rate is 97.31%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by subsequent treatments such as magnetic separation.

[0038] Example 2

[0039] The battery waste powder is placed in a roasting furnace, and a nitrogen + hydrogen mixture (hydrogen content 75%, the same below) is introduced. After exhausting the tail gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 450°C, microwaves are applied and the above hydrogen-containing gas is introduced, wherein the microwave power is 1.0kW and the hydrogen flow rate is 12m 3 / h tons of material, roasted for 10 minutes, and then heated to 530℃, adjusted the microwave power to 1.8kW, and the hydrogen flow rate to 22m 3 / h tons of material, roasted for 25 minutes, then heated to 590℃, adjusted the microwave power to 4.0kW, and the hydrogen flow rate to 25m 3 / h tons of material, after roasting for 20 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:10g / mL, and reacted at 30℃ for 1h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 97.56%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0040] Example 3

[0041] The battery waste powder is placed in a roasting furnace, and a hydrogen + helium mixed gas (hydrogen content 90%, the same below) is introduced. After exhausting the tail gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 460°C, microwaves are applied and the above hydrogen-containing gas is introduced, wherein the microwave power is 1.2kW and the hydrogen flow rate is 13m 3 / h tons of material, roasted for 12 minutes, and then heated to 510℃, adjusted the microwave power to 2.2kW, and the hydrogen flow rate to 25m 3 / h tons of material, roasted for 35 minutes, and then heated to 600℃, the microwave power was adjusted to 4.5kW and the hydrogen flow rate was 30m 3 / h tons of material, after roasting for 30 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:15g / mL, and reacted at 35℃ for 1h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 97.70%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0042] Example 4

[0043] The battery waste powder is placed in a roasting furnace, and hydrogen + nitrogen (hydrogen content 80%, the same below) is introduced. After exhausting the tail gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After heating to 440°C, microwaves are applied and the above hydrogen-containing gas is introduced, wherein the microwave power is 1.5kW and the hydrogen flow rate is 11m 3 / h tons of material, roasted for 20 minutes, and then heated to 550 ° C, adjusted the microwave power to 2.1kW, the hydrogen flow rate to 28m 3 / h tons of material, roasted for 20 minutes, and then heated to 630℃, the microwave power was adjusted to 3.5kW, roasted for 25 minutes, and cooled to below 100℃ in the furnace atmosphere. The cooled roasted product was mixed with water to leach lithium, with a solid-liquid ratio of 1:8g / mL, reacted at 40℃ for 0.5h, and then filtered to obtain leaching residue and leaching phase. The lithium leaching rate was 97.55%, and nickel, cobalt, manganese, and aluminum all entered the leaching residue, which could be separated and recovered by magnetic separation and other treatments.

[0044] Example 5

[0045] The battery waste powder was placed in a roasting furnace and heated to 450°C (the heating rate was selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the charge was controlled to be ≤10°C, the same below), roasted in an air atmosphere for 1 hour, and then hydrogen was introduced to exhaust the exhaust gas in the kiln, and microwaves were applied to continue to introduce hydrogen for 15 minutes, wherein the microwave power was 1.5kW and the hydrogen flow rate was 15m3 / h tons of material, and then the temperature is raised to 490℃, the microwave power is adjusted to 2.5kW, the hydrogen flow rate is 25m 3 / h tons of material, roasted for 35 minutes, and then heated to 620℃, the microwave power was adjusted to 3.0kW and the hydrogen flow rate was 30m 3 / h tons of material, after roasting for 15 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:8g / mL, and reacted at 40℃ for 0.5h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 98.29%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0046] Example 6

[0047] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and then the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 430℃, hydrogen is introduced for roasting for 15 minutes, with the hydrogen flow rate of 10m 3 / h tons of material, and then raise the temperature to 500℃ and adjust the hydrogen flow rate to 20m 3 / h tons of material, roast for 30 minutes, then heat to 610℃, adjust the hydrogen flow rate to 25m 3 / h tons of material, after roasting for 15 minutes, stop the gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:12g / mL, react at 25℃ for 1.5h, and separate the solid and liquid to obtain leaching residue and leaching phase. The lithium leaching rate is 93.51%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0048] Example 7

[0049] The battery waste powder is placed in a roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and then the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 430°C, microwaves are applied and hydrogen is introduced for roasting for 15 minutes, wherein the microwave power is 2.5kW and the hydrogen flow rate is 10m 3 / h tons of material, and then raise the temperature to 500℃ and adjust the hydrogen flow rate to 20m 3 / h tons of material, roast for 30 minutes, then heat to 610℃, adjust the hydrogen flow rate to 25m 3 / h tons of material, after roasting for 15 minutes, stop applying microwaves and gas introduction, cool to below 100°C under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:10 g / mL, react at 25°C for 1.5 hours, and separate the solid and liquid to obtain leaching residue and leaching phase. The lithium leaching rate is 95.89%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by subsequent treatments such as magnetic separation.

[0050] Example 8

[0051] The battery waste powder is placed in a roasting furnace, and hydrogen is introduced to exhaust the tail gas in the kiln. The hydrogen introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 450°C, a magnetic field is applied and hydrogen is introduced for roasting for 10 minutes, wherein the magnetic field intensity is 450mT and the hydrogen flow rate is 10m 3 / h tons of material, and then raise the temperature to 550℃, adjust the hydrogen flow rate to 20m 3 / h tons of material, magnetic field strength 350mT, roasting for 30min, then heating to 590℃, adjusting the hydrogen flow rate to 25m 3 / h tons of material, magnetic field intensity of 550mT, after roasting for 20min, stop applying the magnetic field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:6g / mL, react at 50℃ for 1h, and separate the solid and liquid to obtain leaching residue and leaching phase, the lithium leaching rate is 96.65%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0052] Example 9

[0053] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 440℃, a magnetic field is applied and hydrogen is introduced for roasting for 10 minutes, wherein the magnetic field intensity is 400mT and the hydrogen flow rate is 11m 3 / h tons of material, and then raise the temperature to 500℃ and adjust the hydrogen flow rate to 22m 3 / h tons of material, magnetic field strength 300mT, roasting for 25min, then heating to 615℃, adjusting the hydrogen flow rate to 24m 3 / h tons of material, magnetic field intensity is 600mT, after roasting for 20min, stop applying magnetic field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:8g / mL, react at 35℃ for 45min, solid-liquid separation, and obtain leaching residue and leaching phase, the lithium leaching rate is 96.31%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0054] Example 10

[0055] The battery waste powder is placed in a roasting furnace, and hydrogen + nitrogen (hydrogen content 75%, the same below) is introduced. After exhausting the tail gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 470°C, a magnetic field is applied and the above hydrogen-containing gas is introduced, wherein the magnetic field intensity is 500mT and the hydrogen flow rate is 15m 3 / h tons of material, roasted for 15 minutes, and then heated to 545℃, adjusted the magnetic field strength to 400mT, and the hydrogen flow rate to 25m 3 / h tons of material, roasted for 35 minutes, and then heated to 620℃, adjusted the magnetic field strength to 550mT, and the hydrogen flow rate to 28m 3 / h tons of material, after roasting for 15 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:10g / mL, and reacted at 35℃ for 1h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 96.70%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0056] Embodiment 11

[0057] The battery waste powder is placed in a roasting furnace, and hydrogen + nitrogen (hydrogen content 90%, the same below) is introduced. After exhausting the tail gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After the temperature is raised to 435°C, a magnetic field is applied and the above hydrogen-containing gas is introduced, wherein the magnetic field intensity is 600mT and the hydrogen flow rate is 15m 3 / h tons of material, roasted for 20 minutes, and then heated to 560℃, adjusted the magnetic field strength to 450mT, and the hydrogen flow rate to 24m 3 / h tons of material, roasted for 40 minutes, and then heated to 650℃, adjusted the magnetic field strength to 700mT, and the hydrogen flow rate to 25m 3 / h tons of material, after roasting for 10 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:5g / mL, and reacted at 40℃ for 1.5h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 96.55%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0058] Example 12

[0059] The battery waste powder is placed in a roasting furnace, heated to 460°C in an air atmosphere and roasted for 45 minutes (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the charge is controlled to be ≤10°C, the same below), and a magnetic field is applied after hydrogen is introduced to exhaust the exhaust gas in the kiln. The magnetic field intensity is 550mT and the hydrogen flow rate is 13m 3 / h tons of material, roasted for 15 minutes, and then heated to 530℃, adjusted the magnetic field strength to 500mT, and the hydrogen flow rate to 30m 3 / h tons of material, roasted for 25 minutes, and then heated to 630℃, adjusted the magnetic field strength to 650mT, and the hydrogen flow rate to 30m 3 / h tons of material, after roasting for 20 minutes, cool to below 100℃ in furnace atmosphere. The cooled roasted product is mixed with water to leach lithium, with a solid-liquid ratio of 1:15g / mL, and reacted at 45℃ for 1h, then filtered to obtain leaching residue and leaching phase, with a lithium leaching rate of 96.98%, and nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments.

[0060] Example 13

[0061] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 440℃, a magnetic field is applied and hydrogen is introduced for roasting for 10 minutes, wherein the magnetic field intensity is 500mT and the hydrogen flow rate is 11m 3 / h tons of material, and then raise the temperature to 500℃ and adjust the hydrogen flow rate to 22m 3 / h tons of material, roast for 25 minutes, then heat to 615℃, adjust the hydrogen flow rate to 24m 3 / h tons of material, after roasting for 20 minutes, stop applying the magnetic field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:8g / mL, react at 35℃ for 45 minutes, and separate the solid and liquid to obtain leaching residue and leaching phase, with a lithium leaching rate of 94.96%. Nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0062] Embodiment 14

[0063] The battery waste powder is placed in a roasting furnace, and hydrogen is introduced to exhaust the tail gas in the kiln, and then the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the charge is controlled to be ≤10°C, the same below). After the temperature is raised to 450°C, a magnetic field and microwaves are applied and hydrogen is introduced for roasting for 10 minutes, wherein the magnetic field intensity is 550mT, the microwave power is 1.2kW, and the hydrogen flow rate is 13m 3 / h tons of material, and then raise the temperature to 540℃, adjust the hydrogen flow rate to 23m 3 / h tons of material, microwave power is 1.8kW, magnetic field strength is 350mT, roasting for 30min, then heating to 600℃, adjusting the hydrogen flow rate to 30m 3 / h tons of material, the magnetic field intensity is 600mT, the microwave power is 4.5kW, after roasting for 10min, stop applying the magnetic field, microwave field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:6g / mL, react at 45℃ for 30min, and separate the solid and liquid to obtain leaching residue and leaching phase, the lithium leaching rate is 98.16%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0064] Embodiment 15

[0065] The battery waste powder is placed in a roasting furnace, and hydrogen is introduced to exhaust the tail gas in the kiln, and then the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the charge is controlled to be ≤10°C, the same below). After the temperature is raised to 460°C, hydrogen is introduced and a magnetic field and microwave roasting are applied for 15 minutes, wherein the magnetic field intensity is 450mT, the microwave power is 1.1kW, and the hydrogen flow rate is 15m 3 / h tons of material, and then raise the temperature to 550℃ and adjust the hydrogen flow rate to 25m 3 / h tons of material, microwave power is 2.2kW, magnetic field strength is 400mT, roasting for 25min, then heating to 615℃, adjusting hydrogen flow rate to 28m 3 / h tons of material, the magnetic field intensity is 550mT, the microwave power is 3.5kW, after roasting for 30min, stop applying the magnetic field, microwave field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:12g / mL, react at 35℃ for 60min, and separate the solid and liquid to obtain leaching residue and leaching phase, the lithium leaching rate is 99.04%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0066] Example 16

[0067] The battery waste powder is placed in a roasting furnace, and hydrogen-containing gas (85% hydrogen + 15% nitrogen, the same below) is introduced. After exhausting the exhaust gas in the kiln, the gas introduction is stopped, and the roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10°C, the same below). After heating to 470°C, a magnetic field and microwave are applied and hydrogen is introduced for roasting for 12 minutes, wherein the magnetic field intensity is 600mT, the microwave power is 1.5kW, and the hydrogen flow rate is 12m 3 / h tons of material, and then raise the temperature to 560℃, adjust the hydrogen flow rate to 30m 3 / h tons of material, microwave power is 2.5kW, magnetic field strength is 370mT, roasting for 40min, then heating to 645℃, adjusting magnetic field strength to 700mT, microwave power is 5.0kW, after roasting for 15min, stop applying magnetic field, microwave field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:15g / mL, react at 40℃ for 60min, solid-liquid separation, and leaching residue and leaching phase are obtained, the lithium leaching rate is 99.56%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0068] Embodiment 17

[0069] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and the gas introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 440℃, hydrogen is introduced for roasting for 10 minutes, and the hydrogen flow rate is 15m 3 / h tons of material, and then raise the temperature to 570℃, adjust the hydrogen flow rate to 22m 3 / h tons of material, apply 600mT magnetic field, roast for 25min, stop applying magnetic field, raise temperature to 650℃, adjust hydrogen flow rate to 30m 3 / h tons of material, applying microwave power of 5.0kW, after roasting for 20min, stop applying microwave field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:10g / mL, react at 45℃ for 60min, and separate the solid and liquid to obtain leaching residue and leaching phase, the lithium leaching rate is 95.91%, nickel, cobalt, manganese and aluminum all enter the leaching residue, which can be separated and recovered by magnetic separation and other treatments later.

[0070] Comparative Example 1

[0071] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 550℃, hydrogen is introduced for roasting for 60 minutes, with the hydrogen flow rate of 20m 3 / h tons of material, and then cooled to below 100°C in furnace atmosphere, and then mixed the cooled calcined product with water to leach lithium, wherein the solid-liquid ratio was 1:10 g / mL, and the reaction was carried out at 25°C for 1.5 hours. After solid-liquid separation, leaching residue and leaching phase were obtained, and the lithium leaching rate was 89.33%.

[0072] Comparative Example 2

[0073] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and then the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature reaches 300℃, hydrogen is introduced for roasting for 15 minutes, and the hydrogen flow rate is 20m 3 / h tons of material, and then heated to 430℃ and roasted for 30min, and then heated to 550℃ and roasted for 15min, then stopped gas introduction, cooled to below 100℃ under furnace atmosphere, and then mixed the cooled calcined product with water to leach lithium, wherein the solid-liquid ratio was 1:10g / mL, reacted at 25℃ for 1.5h, and separated the solid and liquid to obtain leached residue and leached phase, with a lithium leaching rate of 75.36%.

[0074] Comparative Example 3

[0075] The battery waste powder was placed in a roasting furnace, and hydrogen was introduced to exhaust the tail gas in the kiln. The hydrogen introduction was stopped, and the roasting furnace was started to heat up (the heating rate was selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge was controlled to be ≤10°C, the same below). After the temperature was raised to 430°C, microwaves were applied and hydrogen was introduced for roasting for 45 minutes, wherein the microwave power was 1.1kW and the hydrogen flow rate was 10m 3 / h tons of material, and then the temperature is raised to 610℃, the microwave power is adjusted to 5kW, the hydrogen flow rate is 25m 3 / h tons of material, after roasting for 15 minutes, stop applying microwaves and gas introduction, cool to below 100°C in furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:10 g / mL, react at 25°C for 1.5 hours, and separate the solid and liquid to obtain leaching residue and leaching phase, with a lithium leaching rate of 85.56%.

[0076] Comparative Example 4

[0077] The battery waste powder is placed in the roasting furnace, hydrogen is introduced to exhaust the tail gas in the kiln, and the hydrogen introduction is stopped. The roasting furnace is started to heat up (the heating rate is selected according to the heating power and processing capacity of the roasting furnace, and the overall temperature difference of the furnace charge is controlled to be ≤10℃, the same below). After the temperature is raised to 440℃, a magnetic field is applied and hydrogen is introduced for roasting for 10 minutes, wherein the magnetic field intensity is 400mT and the hydrogen flow rate is 11m 3 / h tons of material, and then raise the temperature to 500℃ and adjust the hydrogen flow rate to 22m 3 / h tons of material, magnetic field intensity of 300mT, after roasting for 45min, stop applying magnetic field and gas introduction, cool to below 100℃ under furnace atmosphere, and then mix the cooled roasted product with water to leach lithium, wherein the solid-liquid ratio is 1:8g / mL, react at 35℃ for 45min, and separate the solid and liquid to obtain leaching residue and leaching phase, with a lithium leaching rate of 87.12%.

[0078] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0079] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for regenerating lithium battery waste, characterized in that: The following steps are involved: Placing lithium battery waste powder in a roasting furnace, introducing hydrogen-containing gas for reduction roasting to obtain a reduction roasting product, wherein the reduction includes one-stage reduction roasting, two-stage reduction roasting and three-stage reduction roasting; The first stage reduction roasting temperature is 450±20℃, and the hydrogen flow rate in the hydrogen-containing gas is 10-15m 3 / h tons of material, reduction roasting time is 10-20min; The second stage reduction roasting temperature is 530±40℃, and the hydrogen flow rate in the hydrogen-containing gas is 20-30m 3 / h tons of material, the reduction roasting time is 20-40min; The temperature of the three-stage reduction roasting is 620±30℃, and the hydrogen flow rate of the hydrogen-containing gas is 25-30m 3 / h tons of material, reduction roasting time is 10-30min; The lithium battery waste contains at least one of nickel, cobalt and manganese; The method further comprises a reduction roasting product leaching step.

2. The method for regenerating lithium battery waste according to claim 1, characterized in that: The temperature of the first stage reduction roasting is 450±15℃, and the hydrogen flow rate of the hydrogen-containing gas is 12-15m 3 / h tons of material, reduction roasting time is 11-15min; The temperature of the second stage reduction roasting is 530±30℃, and the hydrogen flow rate of the hydrogen-containing gas is 20-30m 3 / h tons of material, reduction roasting time is 25-35min; The temperature of the three-stage reduction roasting is 620±20℃, and the hydrogen flow rate of the hydrogen-containing gas is 25-30m 3 / h tons of material, the reduction roasting time is 15-25min.

3. The method for regenerating lithium battery waste according to claim 1 or 2, characterized in that: The calcination process is enhanced by applying an external field, wherein the external field includes a magnetic field and / or a microwave field.

4. The method for regenerating lithium battery waste according to claim 3, characterized in that: The external field is a uniform magnetic field and / or a microwave field, wherein the magnetic field intensity is 100-600 mT and the microwave power is 1.0-5.0 kW.

5. The method for regenerating lithium battery waste according to claim 3, characterized in that: The external field is a variable magnetic field and / or a variable microwave field, wherein the magnetic field strengths of the first, second and third stages of reduction roasting are 400-600mT, 300-500mT and 500-700mT respectively, and the microwave powers are 1.0-1.5kW, 1.8-2.5kW and 3.0-5.0kW respectively.

6. The method for regenerating lithium battery waste according to claim 5, characterized in that: The magnetic field intensities of the first, second and third stage reduction roasting are 450-600mT, 300-450mT and 550-650mT respectively, and the microwave powers are 1.2-1.5kW, 2.0-2.5kW and 3.5-5.0kW respectively.

7. The method for regenerating lithium battery waste according to claim 3, characterized in that: A magnetic field with an intensity of 100-600 mT is applied in the second reduction stage and / or a microwave field with a power of 1.0-5.0 kW is applied in the third reduction stage.

8. The method for regenerating lithium battery waste according to claim 3, characterized in that: The lithium battery waste powder includes waste powder that has been or has not been pretreated, the pretreatment includes oxidation treatment; the oxidation treatment includes oxidative roasting, the roasting temperature is 450-600° C., and the roasting time is 0.5-2h.

9. The method for regenerating lithium battery waste according to any one of claims 1-2, characterized in that: The hydrogen-containing gas is hydrogen or a mixture of hydrogen and an inert gas, the hydrogen concentration in the hydrogen-containing gas is 50v%-100v%, and the inert gas is nitrogen and / or helium.

10. The method for regenerating lithium battery waste according to claim 9, characterized in that: The pH value of the leaching solution is 7±0.5, the solid-liquid ratio is 1:5-20, the leaching temperature is 10-100°C, and the leaching time is 0.5-2h.