Method for deeply defluorinating and efficiently leaching nickel, cobalt, manganese and lithium from ternary lithium battery waste

Abstract

The invention belongs to the technical field of resource recycling of waste lithium ion batteries, and relates to a method for deeply defluorinating and efficiently leaching nickel, cobalt, manganese and lithium from ternary lithium battery waste, which comprises the following steps: roasting ternary lithium battery powder; mixing the roasted powder with recycled mother liquor, water and acid liquor to carry out slurrying reaction, after the reaction is finished, carrying out solid-liquid separation to obtain a filter cake and mother liquor, and recycling the mother liquor for next slurrying reaction; carrying out heat treatment on the filter cake under an aerobic condition to obtain a solid; and adding water into the solid, stirring, leaching, and carrying out solid-liquid separation to obtain a leachate and carbon-containing tailings. According to the method, the complicated fluorine removal and acid regulation steps in the traditional process are simplified, the whole process is simpler, and the economic benefit is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of waste lithium-ion battery resource recycling technology, and relates to a method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste. Background Technology

[0002] With the rapid development of the new energy vehicle industry, a large number of ternary lithium-ion batteries are entering their end-of-life period, and their recycling is of great significance for resource recycling and environmental protection.

[0003] Currently, the mainstream recycling process involves recovering valuable nickel, cobalt, manganese, and lithium metals from battery cathode powder using hydrometallurgical techniques. However, waste ternary lithium battery powder typically contains a relatively high fluorine content of approximately 0.5% to 1.5%, primarily derived from the decomposition of electrolytes such as LiPF6 and cathode binders such as PVDF. During traditional acid leaching, a large amount of fluorine enters the solution, inevitably leading to the co-precipitation loss of some valuable metals like nickel, cobalt, and manganese during subsequent impurity removal processes using calcium salt precipitation. This reduces metal recovery rates and increases processing costs. Furthermore, traditional acid leaching requires the addition of large amounts of reducing agents such as hydrogen peroxide to reduce high-valence cobalt and manganese, resulting in high auxiliary material consumption. The leachate also has extremely high acidity, with a pH less than 1, necessitating significant amounts of alkali for pH adjustment during subsequent neutralization and impurity removal. This results in a lengthy process, high reagent costs, and poor economic efficiency.

[0004] Therefore, developing a new process that can pre-de-fluorinate deeply and achieve efficient and low-carbon leaching of nickel, cobalt, manganese, and lithium is crucial for improving the economic efficiency and environmental friendliness of ternary battery recycling. Summary of the Invention To address the shortcomings of existing technologies, this invention provides a method for deep defluorination and efficient leaching of nickel-cobalt-manganese lithium from ternary lithium battery waste.

[0005] The method for deep defluorination and efficient leaching of nickel-cobalt-manganese-lithium from ternary lithium battery waste provided by the present invention includes: (1) Calcining the ternary lithium battery powder; (2) The roasted powder is mixed with recycled mother liquor, water and acid to carry out a slurry reaction. After the reaction is completed, filter cake and mother liquor are obtained by solid-liquid separation. The mother liquor is reused for the next slurry reaction. (3) The filter cake is heat-treated under aerobic conditions to obtain a solid; (4) Add water to the solid and stir to leach, and obtain leachate and carbon-containing tailings by solid-liquid separation.

[0006] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the roasting temperature is 400~600℃ and the roasting time is 1~3 hours.

[0007] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the temperature of the slurry reaction is 80~100℃ and the reaction time is 2~6 hours.

[0008] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese, and lithium from ternary lithium battery waste, the acid solution is hydrochloric acid or sulfuric acid.

[0009] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the acid solution is concentrated sulfuric acid, and the concentration after mixing with recycled mother liquor and water is 2.0~4.0 mol / L.

[0010] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the amount of concentrated sulfuric acid added is 110% to 150% of the mass of the roasted powder.

[0011] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the heat treatment temperature is 200~400℃ and the duration is 2~4 hours.

[0012] In the above-mentioned method for deep defluorination and efficient leaching of nickel-cobalt-manganese-lithium from ternary lithium battery waste, the solid-liquid ratio of the solid to the water is 1 g: (2~3 mL).

[0013] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the temperature at which water is added and stirred in the solid is 60~80℃.

[0014] In the above-mentioned method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste, the fluoride ion concentration in the leachate is less than 0.05 g / L and the pH value is greater than 2.0.

[0015] Compared with existing technologies, the method of deep defluorination and efficient leaching of nickel, cobalt, manganese, and lithium from ternary lithium battery waste of the present invention has the following beneficial effects: (1) Deep defluorination: Through the two-stage defluorination process of "slurrying + heat treatment", this invention achieves deep removal of fluorine >99%, and the fluorine concentration in the final leachate can be controlled below 0.05 g / L, which greatly reduces the burden of subsequent solution defluorination and the risk of metal loss. (2) High efficiency leaching and high recovery rate: The comprehensive recovery rate of nickel, cobalt, manganese and lithium in this invention is greater than 99%, and the metal recovery effect is good. (3) Significantly reduced auxiliary material consumption: Since fluoride is removed in advance and the acidity of the leaching stage of this invention is low (pH>2), the amount of neutralizing agents such as NaOH and Na2CO3 required for subsequent impurity removal processes is greatly reduced. At the same time, the use of large amounts of reducing agents such as hydrogen peroxide is avoided, reducing reagent costs and operational hazards.

[0016] (4) Green recycling: The mother liquor after the pulping reaction in this invention can be recycled, which reduces wastewater discharge and improves the economy and environmental protection of the process. (5) Short process flow and low cost: This invention simplifies the complex defluorination and acid adjustment steps in the traditional process, making the overall process simpler and significantly improving economic benefits. Attached Figure Description Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention.

[0017] Figure 1 This is a process flow diagram of the method for deep defluorination and efficient leaching of nickel, cobalt, manganese and lithium from ternary lithium battery waste according to the present invention. Detailed Implementation

[0018] To fully understand the purpose, features, and effects of this invention, the following detailed embodiments are provided. Except as described below, the process methods of this invention employ conventional methods or apparatus in the art. Unless otherwise specified, the terms and expressions used below have the meanings commonly understood by those skilled in the art.

[0019] The technical approach adopted in this invention is as follows: Addressing the problems of severe interference from fluorine impurities, low recovery rates of valuable metals, and high reagent consumption in existing ternary lithium battery recycling processes, this invention proposes a multi-step coupled technology approach of "deep defluorination followed by gentle leaching." Its core lies in achieving deep removal and conversion of fluorine before leaching through a combination of processes: "low-temperature roasting—slurry acid treatment—medium-temperature heat treatment—water leaching." This invention overcomes the limitations of traditional leaching followed by defluorination processes, avoiding metal co-precipitation losses during defluorination. Simultaneously, due to the reduced acidity of the leaching system, the amount of reducing agent and neutralizing alkali used is significantly reduced, resulting in high metal recovery rates, low reagent costs, and a green recycling effect.

[0020] Specifically, the method for deep defluorination and efficient leaching of nickel-cobalt-manganese lithium from ternary lithium battery waste provided by the present invention includes: (1) Pretreatment roasting The ternary lithium battery powder was calcined.

[0021] In some preferred embodiments, the present invention calcines the ternary lithium battery powder at 400~600°C for 1~3 hours to remove organic matter and initially destroy the structure of fluorine-containing substances.

[0022] In some optional embodiments, the roasting temperature is 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, 590℃, or 600℃, or any value between any two of the above values; the roasting time is 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours, or any value between any two of the above values.

[0023] In practice, when the roasting temperature is below 400℃, it is difficult to effectively remove organic matter and initially destroy the structure of fluorine-containing substances; when the roasting temperature is above 600℃, the phase structure of the material may change. When the roasting time is less than 1 hour, it is difficult to effectively remove organic matter; when the roasting time is more than 3 hours, it results in energy waste.

[0024] More preferably, the calcination temperature of the ternary lithium battery powder is 400~500℃; the calcination time is 2~3 hours.

[0025] (2) Slurry reaction The calcined powder is mixed with recycled mother liquor, water and acid to carry out a slurry reaction. After the reaction is completed, the filter cake and mother liquor are obtained by solid-liquid separation. The mother liquor is reused for the next slurry reaction.

[0026] This invention achieves deep removal of fluoride by subjecting the calcined powder to a slurry reaction in an acidic environment.

[0027] In some preferred embodiments, the filter cake is washed again, and the washing liquid is reused in the next slurry reaction.

[0028] In some preferred embodiments, the temperature of the pulping reaction is 80-100°C, and the reaction time is 2-6 hours. Optionally, the temperature of the pulping reaction is 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, or 100°C, or any value between any two of the above values; the reaction time is 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours, or any value between any two of the above values.

[0029] In practice, it has been found that when the temperature of the slurry reaction is below 80℃, the reaction rate slows down and a longer reaction time is required; when the temperature of the slurry reaction is above 100℃, a high-pressure vessel is required. When the duration of the slurry reaction is less than 2 hours, it is difficult for the reaction to occur fully; when the duration of the slurry reaction is more than 6 hours, it results in energy waste.

[0030] More preferably, the temperature of the pulping reaction is 85~95℃; and the duration of the pulping reaction is 4~6 hours.

[0031] In some preferred embodiments, the acid is hydrochloric acid or sulfuric acid, and more preferably concentrated sulfuric acid.

[0032] Concentrated sulfuric acid is a high-concentration sulfuric acid solution commonly found in commercial or laboratory settings, with a concentration range of 95% to 98%.

[0033] The concentration of concentrated sulfuric acid, after mixing with recycled mother liquor and water, is 2.0~4.0 mol / L. The amounts of mother liquor and water added are calculated according to the target concentration control range of sulfuric acid.

[0034] In practice, when the concentration of sulfuric acid is less than 2.0 mol / L, it makes it difficult to effectively remove fluoride at the downstream end; when the concentration of sulfuric acid is greater than 4.0 mol / L, it results in the waste of sulfuric acid.

[0035] In some preferred embodiments, the amount of sulfuric acid added is 110% to 150% of the mass of the calcined powder. Optionally, the amount of sulfuric acid added is 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, or 150% of the mass of the calcined powder, or any value between any two of the above values.

[0036] In practice, it has been found that when the amount of sulfuric acid added is less than 110% of the mass of the roasted powder, it is difficult to achieve a full reaction with the oxides in the material; when the amount of sulfuric acid added is greater than 150% of the mass of the roasted powder, it results in a waste of sulfuric acid.

[0037] (3) Heat treatment The filter cake is heat-treated under aerobic conditions to obtain a solid.

[0038] This invention achieves deep defluorination before leaching valuable metals by heat-treating the filter cake under aerobic conditions, converting residual fluoride in the filter cake into a gaseous form and removing it through tail gas absorption.

[0039] In some preferred embodiments, the aerobic condition is in the air.

[0040] In some preferred embodiments, the filter cake is heat-treated under aerobic conditions at a temperature of 200-400°C for 2-4 hours.

[0041] In some optional embodiments, the heat treatment temperature is 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C, or any value between any two of the above values; the heat treatment duration is 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours, or any value between any two of the above values.

[0042] In practice, it has been found that when the heat treatment temperature is below 200℃, it is difficult to effectively remove fluorine; when the heat treatment temperature is above 400℃, it results in energy waste. When the heat treatment time is less than 2 hours, it is difficult to effectively remove fluorine; when the heat treatment time is more than 4 hours, it results in energy waste.

[0043] More preferably, the filter cake is heat-treated under aerobic conditions at a temperature of 200~350℃ for 2~3.5 hours. Under these conditions, the fluoride removal efficiency can be ensured to be over 99%, and the energy consumption is economical.

[0044] (4) Dissolution and leaching Water is added to the solid and stirred for leaching. The leachate and carbon-containing tailings are obtained by solid-liquid separation.

[0045] The leachate is a low-acidity leachate rich in nickel, cobalt, manganese and lithium, with a fluoride ion concentration of less than 0.05 g / L and a pH value greater than 2.0.

[0046] In some preferred embodiments, during the leaching process, the solid-liquid ratio of the solid to the water is 1 g:(2~3 mL), and the temperature is 60~80°C, thereby fully leaching the valuable metals in the solid into the solution.

[0047] In some preferred embodiments, the carbonaceous tailings are washed once, thereby recovering the valuable metals remaining in the carbonaceous tailings and improving the recovery rate of valuable metals.

[0048] Example The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments, unless otherwise specified, were performed according to conventional methods and conditions. The raw materials used in the following embodiments were all commercially available.

[0049] Example 1 Take 500g of ternary lithium battery powder and place it in a muffle furnace. Calcinate at 500℃ for 2 hours, then cool and remove. Take 100g of the calcined powder and place it in a reactor. Add 440mL of recycled mother liquor (water can be used instead for the first use), add 160g of water, and then add 130% (by weight of the powder) of 98% sulfuric acid. Stir the mixture evenly at room temperature, then heat to 90℃ and maintain the temperature while stirring for 4 hours. After the reaction, perform solid-liquid separation to obtain approximately 260g of filter cake and 425mL of mother liquor, with the mother liquor reserved for recycling. Place the obtained filter cake in a high-temperature furnace and heat-treat at 300℃ for 3 hours in an air atmosphere. Cool and remove. Take 100g of the heat-treated solid and add 250mL of deionized water. Stir and dissolve at 70℃ for 1 hour, then perform solid-liquid separation. Obtain a leachate rich in nickel, cobalt, manganese, and lithium, and carbonaceous tailings.

[0050] The final leachate concentration was 0.04 g / L, with an overall fluoride removal rate of 99.2%. The leaching rates for nickel, cobalt, manganese, and lithium were all above 99.5%. The pH of the leachate was 2.1. Comparative example: Traditional acid leaching process Take 100g of the same 500g ternary lithium battery powder, without the pretreatment of this invention, add 300mL of water to slurry; then add 130g of 98% sulfuric acid, leach at 90℃, and add 50mL of 30% hydrogen peroxide as a reducing agent, react for 4 hours. After the reaction is complete, separate the solid and liquid.

[0051] Testing revealed that the fluoride ion concentration in the leachate was as high as 1.8 g / L, and the leaching rates of nickel, cobalt, and manganese were below 95%. Therefore, subsequent defluorination is necessary, requiring the addition of large amounts of lime, resulting in significant losses due to the co-precipitation of nickel, cobalt, and manganese. Furthermore, the pH of the leachate is <0.5, meaning that subsequent neutralization and impurity removal processes will consume even more alkali. The above comparison shows that the method of the present invention has significant advantages in defluorination efficiency and comprehensive recovery benefits.

[0052] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0053] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0054] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for deep defluorination and efficient leaching of nickel-cobalt-manganese lithium from ternary lithium battery waste, characterized in that, include: (1) Calcining the ternary lithium battery powder; (2) The roasted powder is mixed with recycled mother liquor, water and acid to carry out a slurry reaction. After the reaction is completed, filter cake and mother liquor are obtained by solid-liquid separation. The mother liquor is reused for the next slurry reaction. (3) The filter cake is heat-treated under aerobic conditions to obtain a solid; (4) Add water to the solid and stir to leach, and obtain leachate and carbon-containing tailings by solid-liquid separation.

2. The method according to claim 1, characterized in that, The roasting temperature is 400~600℃, and the roasting time is 1~3 hours.

3. The method according to claim 1, characterized in that, The temperature of the pulping reaction is 80~100℃, and the reaction time is 2~6 hours.

4. The method according to claim 1, characterized in that, The acid solution is hydrochloric acid or sulfuric acid.

5. The method according to claim 1, characterized in that, The acid solution is concentrated sulfuric acid, and its concentration after mixing with recycled mother liquor and water is 2.0~4.0 mol / L.

6. The method according to claim 5, characterized in that, The amount of concentrated sulfuric acid added is 110% to 150% of the mass of the calcined powder.

7. The method according to claim 1, characterized in that, The heat treatment is performed at a temperature of 200~400℃ for 2~4 hours.

8. The method according to claim 1, characterized in that, The solid-liquid ratio of the solid to the water is 1 g: (2~3 mL).

9. The method according to claim 1, characterized in that, The temperature at which water is added to the solid and stirred is 60~80℃.

10. The method according to claim 1, characterized in that, The leachate has a fluoride ion concentration of less than 0.05 g / L and a pH value greater than 2.0.

Images