Method for recycling lithium and graphite in waste batteries in a full chain integration

Abstract

This disclosure presents a method for the integrated recycling of lithium and graphite from waste batteries, belonging to the field of battery recycling technology. The method includes roasting and water leaching of battery black powder obtained from waste batteries to extract lithium, followed by flotation of the water-leached residue. The flotation process includes: a primary roughing stage using a flotation agent to obtain a roughing foam and a roughing liquid; and at least one secondary cleaning stage of the roughing foam to finally obtain a carbon-containing concentrate. The flotation agent includes a graphite collector, a flocculant, and a foaming agent. This method is simple and easy to implement, effectively recycling lithium and graphite from waste batteries with high recovery rates for both, thus avoiding resource waste.

Description

Technical Field

[0001] This disclosure relates to the field of battery recycling technology, and more specifically, to a method for the integrated recycling of lithium and graphite from waste batteries across the entire supply chain. Background Technology

[0002] With the rapid development of the new energy industry, the price of battery-grade lithium carbonate has risen from nearly 50,000 yuan / ton at the beginning of 2021 to 300,000 yuan / ton in March 2023. During this period, the price once exceeded 550,000 yuan / ton.

[0003] Currently, the recycling processes for spent ternary lithium batteries are mainly divided into dismantling and hydrometallurgical processes, and pyrometallurgical processes. Hydrometallurgical processes primarily involve leaching battery black powder with organic or inorganic acids and reducing agents. The problem is that the lithium recovery rate is generally below 80%, and the graphite produced during this process is treated as hazardous waste, resulting in significant resource waste. Pyrometallurgical processes, on the other hand, suffer from high energy consumption and often fail to recover both lithium and graphite.

[0004] By recycling valuable metals and graphite from used batteries, these components can be returned to the battery itself, achieving full-component recycling and enabling the construction of an "integrated industrial park across the entire supply chain." This can reduce costs, increase efficiency, and avoid resource waste. However, currently, there is no method that can simultaneously and effectively recycle lithium and graphite from used batteries.

[0005] In view of this, this disclosure is hereby made. Summary of the Invention

[0006] The purpose of this disclosure is to provide a method for the integrated recycling of lithium and graphite from waste batteries across the entire supply chain. This method is simple and easy to implement, and can effectively recycle lithium and graphite from waste batteries with high recovery rates for both lithium and graphite, thus avoiding resource waste.

[0007] To achieve the above-mentioned objectives of this disclosure, the following technical solutions may be adopted:

[0008] This disclosure includes a method for recycling lithium and graphite from waste batteries in an integrated, end-to-end manner, comprising the following steps:

[0009] The battery black powder obtained from waste batteries is roasted and extracted by water leaching to extract lithium, and the water leaching residue is floated.

[0010] The flotation process includes: using a flotation agent to perform a roughing process on the water-leached residue to obtain a roughing froth material and a roughing liquid material; and performing at least one cleaning process on the roughing froth material to finally obtain a carbon-containing concentrate.

[0011] Flotation agents include graphite collectors, modifiers, and frothers; modifiers include flocculants.

[0012] In some embodiments of this disclosure, the graphite collector includes at least one of kerosene and diesel oil;

[0013] And / or, the flocculant includes at least one of starch, sodium carboxymethyl cellulose, and dextrin;

[0014] And / or, the foaming agent includes at least one of methyl isobutyl methanol, pine oil and 2-octanol.

[0015] In some embodiments of this disclosure, the amount of graphite collector used is 50 g / t to 500 g / t; and / or, the amount of flocculant used is 500 g / t to 2000 g / t; and / or, the amount of foaming agent used is 50 g / t to 400 g / t.

[0016] In some embodiments of this disclosure, the modifier further includes at least one of a pH adjuster and a stabilizer.

[0017] In some embodiments of this disclosure, the pH adjuster includes at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate, and sodium hydroxide;

[0018] And / or, the stabilizer includes at least one of aluminum sulfate, aluminum nitrate, aluminum chloride, polyaluminum chloride, ferric sulfate, ferric nitrate, ferrous sulfate, ferric chloride, ferrous chloride, magnesium nitrate, magnesium chloride, and magnesium sulfate.

[0019] In some embodiments of this disclosure, the amount of pH adjuster used is 200 g / t to 4000 g / t, and / or the amount of stabilizer used is 200 g / t to 2000 g / t.

[0020] In some embodiments of this disclosure, the number of refining times is n, where n≥2 and is an integer; during the first n-1 refining processes, after each refining process, the n-1th refined foam material and the n-1th refined middlings are obtained respectively; the n-1th refined foam material is used as the raw material to be selected for the nth refining.

[0021] In some embodiments of this disclosure, when n=2, the middlings from the first finest ...

[0022] In some embodiments of this disclosure, when n=2, the ore obtained from the second refining is returned to the first refining process as raw material to be refined.

[0023] In some embodiments of this disclosure, when n≥3, the ore obtained from the (n-1)th refining is returned as raw material to the (n-2)th refining process.

[0024] In some embodiments of this disclosure, the ore obtained from the nth refining process is returned as raw material to the (n-1)th refining process.

[0025] In some embodiments of this disclosure, when middlings ore is returned as raw material to the second refining process, the foam material from the first refining process is combined with the middlings ore from the third refining process for grinding and washing before the second refining process.

[0026] In some embodiments of this disclosure, the scrubbing time is 2 min to 15 min.

[0027] In some embodiments of this disclosure, the selecting agent used in each selection process independently includes a graphite collector and a foaming agent.

[0028] In some embodiments of this disclosure, the graphite collector used in each refining process includes at least one of kerosene and diesel oil;

[0029] And / or, the foaming agent used in each selection process includes at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

[0030] In some embodiments of this disclosure, the amount of graphite collector used in each refining process is 0-150 g / t; and / or, the amount of foaming agent used in each refining process is 0-150 g / t.

[0031] In some embodiments of this disclosure, flotation further includes: scavenging the roughing slurry at least once to finally obtain carbon-containing tailings.

[0032] In some embodiments of this disclosure, the number of scavenging cycles is m, where m ≥ 2 and is an integer; during the first m-1 scavenging cycles, the remaining slurry from the m-1th scavenging cycle and the foamed ore from the m-1th scavenging cycle are obtained after each scavenging cycle; the remaining slurry from the m-1th scavenging cycle is used as the raw material to be scavenged for the mth scavenging cycle.

[0033] In some embodiments of this disclosure, when m=2, the first scavenged froth ore obtained from the first scavenging is returned to the roughing process as raw material to be selected.

[0034] In some embodiments of this disclosure, when m=2, the ore obtained from the second scavenging froth in the second scavenging is returned to the first scavenging process as raw material to be scavenged.

[0035] In some embodiments of this disclosure, when m≥3, the froth ore obtained from the (m-1)th scavenging is returned as raw material to the (m-2)th scavenging process.

[0036] In some embodiments of this disclosure, the froth ore obtained from the m-th scavenging is returned as raw material to the (m-1)-th scavenging process.

[0037] In some embodiments of this disclosure, the scavenging agent used in each scavenging process independently includes a graphite collector and a foaming agent.

[0038] In some embodiments of this disclosure, the graphite collector used in each scavenging process includes at least one of kerosene and diesel oil;

[0039] And / or, the foaming agent used in each scavenging process includes at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

[0040] In some embodiments of this disclosure, the amount of graphite collector used in each scavenging process is 0-150 g / t; and / or, the amount of frother used in each scavenging process is 0-150 g / t.

[0041] In some embodiments of this disclosure, the number of coarse selections is 1, the number of fine selections is 4, and the number of sweep selections is 2.

[0042] In some embodiments of this disclosure, the main sources of battery black powder include lithium-containing cathode materials and graphite-containing anode materials.

[0043] In some embodiments of this disclosure, the sources of battery black powder also include at least one of current collector and battery impurities.

[0044] In some embodiments of this disclosure, the current collector includes copper foil or aluminum foil.

[0045] In some embodiments of this disclosure, the battery black powder contains, by mass percentage, 30%-55% carbon, 3%-7% Li, 10%-35% Ni, 2%-5% Co, 2%-5% Mn, 0.055-1% Cu, 0.05%-1% Al, and 0.05%-1% Fe.

[0046] In some embodiments of this disclosure, the preparation of battery black powder includes discharging, crushing, pyrolyzing and sieving waste batteries.

[0047] In some embodiments of this disclosure, calcination includes at least one of the following features:

[0048] Feature 1: Firing temperature is 400℃-800℃;

[0049] Feature 2: Calcination time is 30 min - 180 min;

[0050] Feature 3: The roasting is carried out in an oxygen-free environment.

[0051] In some embodiments of this disclosure, the anaerobic environment is provided by nitrogen or an inert gas.

[0052] In some embodiments of this disclosure, lithium extraction by water leaching includes a water leaching process, wherein water leaching includes at least one of the following features:

[0053] Feature 1: The solid-liquid ratio during water immersion is 1:3-1:10;

[0054] Feature 2: The water immersion temperature is 25℃-90℃;

[0055] Feature 3: Immersion time is 30-120 minutes;

[0056] Feature 4: Water immersion is carried out under stirring conditions.

[0057] In some embodiments of this disclosure, the stirring speed during the water immersion process is 500 rpm to 2000 rpm.

[0058] In some embodiments of this disclosure, water immersion lithium extraction further includes a lithium extraction process, wherein the lithium extraction method includes evaporating the water immersion liquid obtained from the water immersion process.

[0059] In some embodiments of this disclosure, evaporation is carried out by water bath evaporation.

[0060] In some embodiments of this disclosure, the temperature of the water bath evaporation is 80°C-100°C.

[0061] In some embodiments of this disclosure, the water-leached residue is further dispersed prior to flotation.

[0062] In some embodiments of this disclosure, the dispersion is ultrasonic dispersion.

[0063] In some embodiments of this disclosure, ultrasonic dispersion includes at least one of the following features:

[0064] Feature 1: Ultrasonic dispersion is carried out by mixing water-leached residue with water at a liquid-to-solid ratio of 1:3 to 1:10;

[0065] Feature 2: Ultrasonic stirring intensity is 300rpm-1000rpm;

[0066] Feature 3: The ultrasonic dispersion time is 5 min-20 min.

[0067] In some embodiments of this disclosure, after flotation, the flotation tailings product is further processed.

[0068] Post-treatment includes acid leaching, impurity removal, and extraction.

[0069] This disclosure achieves a high Li leaching rate by roasting and water leaching lithium from battery black powder obtained from waste batteries. The resulting water-leached residue is subjected to a specific flotation process. A frother used in this process increases the amount of foam, which is beneficial for flotation. A flocculant is applied to the water-leached residue to cause flocculation, and then a graphite collector is used to effectively capture the graphite.

[0070] This method is simple and easy to implement, and can effectively recycle lithium and graphite from waste batteries. The recovery rates of both lithium and graphite are high, thus avoiding resource waste. Attached Figure Description

[0071] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 This is an overall flow chart of the integrated, end-to-end recycling method for lithium and graphite from waste batteries provided in this disclosure;

[0073] Figure 2 A flowchart of the flotation process in the integrated, end-to-end recycling method for lithium and graphite from waste batteries provided in this disclosure. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0075] The following is a detailed explanation of the integrated, end-to-end recycling method for lithium and graphite from waste batteries provided in this disclosure.

[0076] Please refer to the above as well. Figure 1 and Figure 2 This disclosure proposes a method for the integrated recycling of lithium and graphite from waste batteries, comprising the following steps: roasting and water leaching lithium from battery black powder obtained from waste batteries, and flotation of the water leaching residue.

[0077] For reference, the main sources of battery black powder may include lithium-containing cathode materials and graphite-containing anode materials.

[0078] For example, lithium-containing cathode materials may include at least one of binary cathode materials, ternary cathode materials, quaternary cathode materials, and more diverse cathode materials.

[0079] In some embodiments, the metallic elements contained in the binary cathode material may, for example but not limited to, be nickel and cobalt; the elements contained in the ternary cathode material may, for example but not limited to, be nickel, cobalt, and manganese; and the elements contained in the quaternary cathode material may, for example but not limited to, be nickel, cobalt, manganese, and aluminum.

[0080] Furthermore, the sources of the aforementioned battery black powder may also include at least one of current collector and battery impurities.

[0081] The current collector may include, for example, copper foil or aluminum foil. Battery impurities may include, for example, iron filings.

[0082] For reference, by mass percentage, the fixed carbon content in battery black powder can be 30%-55% (e.g., 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, or 55%, etc.), the Li content can be 3%-7% (e.g., 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, or 7%, etc.), the Ni content can be 10%-35% (e.g., 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, or 35%, etc.), and the Co content can be 2%-5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%). The following are the possible values ​​for the content of Fe: 4.5% or 5%, Mn content can be 2%-5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%), Cu content can be 0.055-1% (e.g., 0.055%, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 0.8% or 1%), Al content can be 0.05%-1% (e.g., 0.05%, 0.08%, 0.1%, 0.2%, 0.5%, 0.8% or 1%), and Fe content can be 0.05%-1% (e.g., 0.05%, 0.08%, 0.1%, 0.2%, 0.5%, 0.8% or 1%).

[0083] It should be noted that, depending on the usage of waste batteries, the chemical composition and content of the battery black powder obtained from them are not limited to the above range and can be determined on a case-by-case basis.

[0084] In some alternative embodiments, the preparation of battery black powder may include discharging, crushing, pyrolyzing and sieving waste batteries.

[0085] The above-mentioned discharge, fragmentation, and pyrolysis can all be carried out using conventional methods, which will not be elaborated on here.

[0086] For reference, the roasting temperature during the roasting process can be 400℃-800℃, such as 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃ or 800℃, or any other value within the range of 400℃-800℃.

[0087] The roasting time can be 30min-180min, such as 30min, 50min, 80min, 100min, 120min, 150min or 180min, or any other value within the range of 30min-180min.

[0088] In some specific alternative embodiments, the calcination temperature can be 500°C and the calcination time can be 180 min.

[0089] In some preferred embodiments, calcination is carried out in an anaerobic environment. The anaerobic environment can be provided by nitrogen or an inert gas (such as argon or helium).

[0090] It should be noted that this disclosure does not use any additives during the calcination process. The battery black powder is directly calcined in an oxygen-free environment, which does not introduce other impurity ions, thus facilitating subsequent impurity removal. In addition, the calcination treatment can remove binders (such as PVDF) in the positive electrode active material, greatly improving the difference in surface floatability between the positive and negative electrode active materials, which is beneficial for flotation separation of the positive and negative electrode materials.

[0091] For reference, water leaching lithium extraction includes a water leaching process, in which the solid-liquid ratio can be 1:3 to 1:10, such as 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, or any other value within the range of 1:3 to 1:10.

[0092] The water immersion temperature can be between 25℃ and 90℃, such as 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, or 90℃, or any other value within the range of 25℃ to 90℃. In some further optional embodiments, the water immersion temperature is 25℃ to 90℃.

[0093] The immersion time can be 30min-120min, such as 30min, 50min, 80min, 100min or 120min, or any other value within the range of 30min-120min.

[0094] In some preferred embodiments, water immersion is carried out under stirring conditions to improve the immersion effect and thus increase the lithium leaching rate.

[0095] For example, the stirring speed during the water immersion process can be 500rpm-2000rpm, such as 500rpm, 800rpm, 1000rpm, 1200rpm, 1500rpm, 1800rpm or 2000rpm.

[0096] It should be noted that the above water immersion process can be carried out only once, or it can be repeated multiple times as needed.

[0097] In some specific optional embodiments, the water immersion solid-liquid ratio can be 1:5, the water immersion temperature can be 80°C, the water immersion time can be 60 min, the stirring speed can be 1500 rpm, and the number of water immersions can be 2.

[0098] As mentioned above, the water immersion process uses high stirring intensity and high temperature, which on the one hand helps to improve the lithium leaching rate, and on the other hand, the surface of the positive and negative electrode active materials is exposed more completely under high stirring intensity, which helps to further increase the surface difference of the positive and negative electrode materials.

[0099] Furthermore, water leaching lithium extraction also includes a lithium extraction process, which involves evaporating the water leaching solution obtained from the water leaching process, or evaporation to precipitate lithium.

[0100] For example, evaporation can be carried out by water bath evaporation.

[0101] The temperature for water bath evaporation can be between 80℃ and 100℃, such as 80℃, 85℃, 90℃, 95℃, or 100℃, until the water is completely evaporated.

[0102] In some specific alternative implementations, the water bath evaporation temperature is 90°C.

[0103] As mentioned above, high-purity lithium-containing materials can be directly obtained by water leaching, with a recovery rate exceeding 80%. The remaining lithium is then processed through a flotation process and subsequently subjected to acid leaching, resulting in a final lithium recovery rate of ≥93% for the entire process.

[0104] In this disclosure, the water-leached residue can be dispersed before flotation.

[0105] For reference, the dispersion form can be ultrasonic dispersion.

[0106] In some embodiments, ultrasonic dispersion can be performed by mixing water-impregnated residue with water at a liquid-to-solid ratio of 1:3 to 1:10 (e.g., 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10).

[0107] The ultrasonic stirring intensity can be 300rpm-1000rpm, such as 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm or 1000rpm, or any other value within the range of 300rpm-1000rpm.

[0108] The ultrasonic dispersion time can be 5 min to 20 min, such as 5 min, 8 min, 10 min, 12 min, 15 min, 18 min or 20 min, or any other value within the range of 5 min to 20 min.

[0109] In some specific alternative embodiments, the solid-liquid ratio corresponding to ultrasonic dispersion can be 1:5, the stirring intensity can be 500 rpm, and the dispersion time can be 10 min.

[0110] Dispersing the water-leached residue before flotation makes it easier to separate graphite in subsequent flotation.

[0111] In this disclosure, flotation can be performed in a flotation machine.

[0112] For reference, flotation includes: using a flotation agent to perform a roughing process on water-leached residue to obtain a roughing froth material and a roughing liquid material; and performing at least one cleaning process on the roughing froth material to finally obtain a carbon-containing concentrate.

[0113] The flotation agents used in the roughing process may include graphite collectors, modifiers, and frothers; modifiers include flocculants.

[0114] The graphite collector may, by way of example but not limitation, include at least one of kerosene and diesel oil. The flocculant may, by way of example but not limitation, include at least one of starch (preferably soluble starch, such as corn starch), sodium carboxymethyl cellulose, and dextrin. The foaming agent may, by way of example but not limitation, include at least one of methyl isobutyl methanol (MIBC), pine oil, and 2-octanol.

[0115] In some implementations, during the roughing process, the amount of graphite collector can be 50 g / t to 500 g / t, such as 50 g / t, 80 g / t, 100 g / t, 150 g / t, 200 g / t, 250 g / t, 300 g / t, 350 g / t, 400 g / t, 450 g / t, or 500 g / t, or any other value within the range of 50 g / t to 500 g / t.

[0116] If the amount of graphite collector used is less than 50 g / t, it is not conducive to the quality of graphite products and the recovery rate is low; if it is more than 500 g / t, it is not conducive to the fixed carbon content of graphite products.

[0117] During the roughing process, the amount of flocculant used can be 500g / t-2000g / t, such as 500g / t, 800g / t, 1000g / t, 1200g / t, 1500g / t, 1800g / t or 2000g / t, or any other value within the range of 500g / t-2000g / t.

[0118] If the amount of flocculant used is less than 500g / t, it will be detrimental to the quality of graphite products; if it is more than 2000g / t, it will result in a lower graphite recovery rate.

[0119] During the roughing process, the amount of foaming agent can be 50g / t-400g / t, such as 50g / t, 100g / t, 150g / t, 200g / t, 250g / t, 300g / t, 350g / t or 400g / t, or any other value within the range of 50g / t-400g / t.

[0120] If the amount of foaming agent is less than 50g / t, it will be detrimental to the recovery rate of graphite products; if it is more than 400g / t, it will be detrimental to the quality of graphite products.

[0121] Furthermore, the modifiers used in the roughing process may also include at least one of pH adjusters and stabilizers.

[0122] The pH adjuster may, by way of example but not by way of limitation, include at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate and sodium hydroxide.

[0123] Stabilizers may, by way of example but not by way of limitation, include at least one of aluminum sulfate, aluminum nitrate, aluminum chloride, polyaluminum chloride, ferric sulfate, ferric nitrate, ferrous sulfate, ferric chloride, ferrous chloride, magnesium nitrate, magnesium chloride, and magnesium sulfate.

[0124] In some implementations, during the roughing process, the amount of pH adjuster can be 200 g / t to 4000 g / t, such as 200 g / t, 500 g / t, 800 g / t, 1000 g / t, 1500 g / t, 2000 g / t, 2500 g / t, 3000 g / t, 3500 g / t, or 4000 g / t, or any other value within the range of 200 g / t to 4000 g / t.

[0125] If the amount of pH adjuster is less than 200g / t, it will be detrimental to the quality of graphite products; if it is more than 4000g / t, it will be detrimental to the quality of graphite products.

[0126] During the roughing process, the amount of stabilizer can be 200g / t-2000g / t, such as 200g / t, 500g / t, 800g / t, 1000g / t, 1200g / t, 1500g / t, 1800g / t or 2000g / t, or any other value within the range of 200g / t-2000g / t.

[0127] If the amount of stabilizer is less than 200g / t, it will be detrimental to the recovery rate of graphite products; if it is more than 2000g / t, it will be detrimental to the quality of graphite products.

[0128] In some specific optional embodiments, the graphite collector used in the roughing process is kerosene, the flocculant is starch, the foaming agent is MIBC, the pH adjuster is calcium oxide, and the stabilizer is aluminum sulfate; wherein, the amount of kerosene is 212 g / t, the amount of starch is 1500 g / t, the amount of MIBC is 174 g / t, the amount of calcium oxide is 2000 g / t, and the amount of aluminum sulfate is 1000 g / t.

[0129] Continuing from the above, the principle of the roughing process includes: the frother used increases the amount of foam, which is beneficial for flotation; the flocculant used acts on the water-leached residue (such as cobalt-manganese products) to cause flocculation, and then the graphite is effectively captured by the graphite collector. The pH adjuster used can work with the flocculant to improve the flocculation effect, and the stabilizer used can increase the foam half-life, increase the foam stabilizer, and reduce the amount of frother used.

[0130] Furthermore, the foam material obtained from the coarse selection is further refined.

[0131] The preset selection count is n times, where n ≥ 2 and is an integer. For example, n can be 1, 2, 3, 4 or more.

[0132] In the first n-1 refining processes, each refining process yields the n-1th refined foam material and the n-1th refined middlings; the n-1th refined foam material is used as the raw material to be refined in the nth refining process (i.e., the next refining process).

[0133] When n=2, the middlings from the first refining process can be returned to the roughing process as raw material. Furthermore, the middlings from the second refining process can be returned to the first refining process as raw material.

[0134] When n≥3, the middlings from the (n-1)th refining process can be returned as raw material to the (n-2)th refining process. Furthermore, the middlings from the nth refining process can also be returned as raw material to the (n-1)th refining process.

[0135] By using a closed-circuit cleaning method, that is, the middlings obtained from the cleaning process are not discharged externally, the recovery rate can be improved.

[0136] In some implementations, when middlings from the first refining process are returned as raw materials to the second refining process, the middlings from the first refining process are combined with the middlings from the third refining process (i.e., the middlings from the third refining process) before the second refining process is carried out for grinding and washing.

[0137] The scrubbing time can be, for example, 2 min to 15 min, such as 2 min, 5 min, 8 min, 10 min, 12 min, or 15 min. In some specific alternative embodiments, the scrubbing time can be 5 min.

[0138] Grinding and scrubbing can be carried out in equipment such as vertical mills or ball mills.

[0139] Grinding and scrubbing can create a fresh surface for graphite, which helps to increase the fixed carbon content of graphite products.

[0140] In this disclosure, the selecting agents used in each selection process may independently include a graphite collector and a foaming agent.

[0141] The graphite collector used in each refining process may, by way of example but not limitation, include at least one of kerosene and diesel oil. The foaming agent used in each refining process may, by way of example but not limitation, include at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

[0142] In some implementations, the amount of graphite collector used in each refining process can be 0-150 g / t, such as 0 g / t, 5 g / t, 10 g / t, 20 g / t, 50 g / t, 80 g / t, 100 g / t, 120 g / t or 150 g / t, or any other value within the range of 0-150 g / t.

[0143] The amount of foaming agent used in each selection process can be 0-150g / t, such as 0g / t, 5g / t, 10g / t, 20g / t, 50g / t, 80g / t, 100g / t, 120g / t or 150g / t, or any other value within the range of 0-150g / t.

[0144] In some specific optional embodiments, the graphite collector used in each purification process can be kerosene, and the foaming agent can be MIBC. Taking a purification process of 4 times as an example, the amount of kerosene used in the first purification can be 53 g / t, and the amount of MIBC can be 58 g / t; the amount of kerosene used in the second purification can be 53 g / t, and the amount of MIBC can be 58 g / t; the amount of kerosene used in the third purification can be 53 g / t, and the amount of MIBC can be 29 g / t; the amount of kerosene used in the fourth purification can be 26.5 g / t, and the amount of MIBC can be 0 g / t.

[0145] Furthermore, flotation may also include: scavenging the roughing slurry at least once to finally obtain carbon-containing tailings.

[0146] The preset number of scans is m, where m ≥ 2 and is an integer. For example, m can be 1, 2, 3, 4 or more.

[0147] In the first m-1 scavenging processes, after each scavenging, the remaining slurry from the m-1th scavenging and the middlings from the m-1th scavenging froth are obtained respectively; the remaining slurry from the m-1th scavenging is used as raw material to be screened for the mth scavenging (i.e. the next scavenging).

[0148] When m=2, the middlings from the first scavenging process can be returned to the roughing process as raw material. Furthermore, the middlings from the second scavenging process can be returned to the first scavenging process as raw material.

[0149] When m≥3, the middlings ore from the (m-1)th scavenging process can be returned as raw material to the (m-2)th scavenging process. Furthermore, the middlings ore from the mth scavenging process can also be returned as raw material to the (m-1)th scavenging process.

[0150] In this disclosure, the scavenging agent used in each scavenging process may independently include a graphite collector and a foaming agent.

[0151] The graphite collector used in each scavenging process may, by way of example but not limitation, include at least one of kerosene and diesel oil. The frother used in each scavenging process may, by way of example but not limitation, include at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

[0152] In some implementations, the amount of graphite collector used in each scavenging process can be 0-150 g / t, such as 0 g / t, 5 g / t, 10 g / t, 20 g / t, 50 g / t, 80 g / t, 100 g / t, 120 g / t or 150 g / t, or any other value within the range of 0-150 g / t.

[0153] The amount of frother used in each scavenging process can be 0-150 g / t, such as 0 g / t, 5 g / t, 10 g / t, 20 g / t, 50 g / t, 80 g / t, 100 g / t, 120 g / t or 150 g / t, or any other value within the range of 0-150 g / t.

[0154] If the amount of graphite collector used in each scavenging process exceeds 150 g / t, it will be detrimental to the quality of graphite products; if the amount of frother used in each scavenging process exceeds 150 g / t, it will be detrimental to the quality of graphite products.

[0155] In some specific optional embodiments, the graphite collector used in each scavenging process can be kerosene, and the frother can be MIBC. Taking two scavenging cycles as an example, the amount of kerosene used in the first scavenging cycle can be 106 g / t, and the amount of MIBC can be 58 g / t; the amount of kerosene used in the second scavenging cycle can be 53 g / t, and the amount of MIBC can be 58 g / t.

[0156] In some specific optional embodiments of this disclosure, the number of coarse flotation cycles is 1, the number of fine flotation cycles is 4, and the number of sweep flotation cycles is 2, that is, the corresponding flotation process is a "one coarse, four fine, two sweep" process.

[0157] Continuing from the above, the flotation process disclosed herein employs a flocculation flotation technique. By adding reagents to the water-leached residue (such as cobalt-manganese products), flocculation is achieved, and its floatability is inhibited, further improving the flotation separation efficiency of graphite. The addition of stabilizers during flotation has a certain stabilizing effect on the flotation foam, increasing the foam's half-life and reducing the amount of graphite collector and frother required.

[0158] Furthermore, after flotation, the flotation tailings products can be further processed, such as acid leaching, impurity removal, and extraction.

[0159] It should be noted that the specific processing procedures and conditions involved in the above post-processing can be referred to the corresponding routine operations, and will not be elaborated on here.

[0160] The features and performance of this disclosure will be further described in detail below with reference to embodiments.

[0161] Example 1

[0162] Please refer to the above as well. Figure 1 and Figure 2 This embodiment provides a method for the integrated recycling of lithium and graphite from waste batteries across the entire supply chain, including the following steps:

[0163] S1: Discharge, crush, pyrolyze, and screen waste ternary lithium batteries to obtain battery black powder (i.e., feed).

[0164] The sources of the black powder in this battery include lithium nickel cobalt manganese oxide ternary cathode material, graphite anode material, current collectors consisting of copper and aluminum foil, and battery impurities (iron filings).

[0165] By mass percentage, the battery black powder contains 44.10% fixed carbon, 4.04% Li, 26.80% Ni, 3.39% Co, 2.56% Mn, 0.11% Cu, 0.10% Al, and 0.10% Fe.

[0166] S2: The battery black powder is roasted in an oxygen-free environment.

[0167] The anaerobic environment was provided by nitrogen, the calcination temperature was 550℃, and the calcination time was 180min.

[0168] S3: Place the roasted material into a container for water immersion. The water immersion conditions are: solid-liquid ratio of 1:5, water temperature of 80℃, stirring speed of 1500rpm, water immersion time of 60min, and water immersion twice.

[0169] S4 Evaporation and Lithium Deposition: The water-immersed solution is concentrated by water bath evaporation. The water bath is heated until the water is completely evaporated.

[0170] S5: Ultrasonic dispersion: Filter the material obtained in S4, put the filtered water-soaked residue into a container, add pure water to make the liquid-to-solid ratio 1:10, stir at 500 rpm, and ultrasonically disperse for 10 min.

[0171] S6: Flotation operation: The ultrasonically dispersed material is added to the flotation machine, and the flotation adopts a closed-loop process of "one roughing, four cleaning, and two scavenging".

[0172] The roughed foam material obtained from the roughing process is subjected to the first cleaning process to obtain the first cleaned foam material and the first cleaned middlings (denoted as middlings 3). Middlings 3 is returned to the roughing process as raw material to be processed.

[0173] The first-selected foam material is subjected to a second-selection process to obtain the second-selected foam material and the second-selected middlings (denoted as middlings 4). Middlings 4 is returned to the first-selection process as raw material to be selected.

[0174] The second-selected foam material is subjected to a third-selection process to obtain the third-selected foam material and the third-selected middlings (denoted as middlings 5). Middlings 5 ​​is returned as raw material to the second-selection process and ground and scrubbed with the first-selected foam material in a vertical mill for 5 minutes.

[0175] The foam material from the third refining process is subjected to a fourth refining process to obtain concentrate and middlings from the fourth refining process (denoted as middlings 6). Middlings 6 is returned to the third refining process as raw material to be refined.

[0176] The roughing liquid obtained from the roughing process is subjected to the first scavenging process to obtain the first scavenged froth middlings (denoted as middlings 2) and the remaining slurry from the first scavenging process. Middlings 2 is returned to the roughing process as raw material to be processed.

[0177] The remaining slurry from the first scavenging process is subjected to a second scavenging process to obtain tailings and middlings from the second scavenging process (denoted as middlings 1). Middlings 1 is returned to the first scavenging process as raw material to be processed.

[0178] The flotation agents used in the roughing process include pH adjuster (calcium oxide, 2000 g / t), stabilizer (aluminum sulfate, 1000 g / t), flocculant (corn starch, 1500 g / t), graphite collector (kerosene, 212 g / t), and frother (MIBC, 174 g / t).

[0179] The refining agents used in each refining process include a graphite collector (kerosene) and a foaming agent (MIBC, optional). Specifically, the amount of kerosene used in the first refining process is 53 g / t, and the amount of MIBC used is 58 g / t; the amount of kerosene used in the second refining process is 53 g / t, and the amount of MIBC used is 58 g / t; the amount of kerosene used in the third refining process is 53 g / t, and the amount of MIBC used is 29 g / t; and the amount of kerosene used in the fourth refining process is 26.5 g / t, and the amount of MIBC used is 0 g / t.

[0180] The scavenging agents used in each scavenging process include graphite collector (kerosene) and frother (MIBC). Specifically, the amount of kerosene used in the first scavenging process is 106 g / t, and the amount of MIBC used is 58 g / t; the amount of kerosene used in the second scavenging process is 53 g / t, and the amount of MIBC used is 58 g / t.

[0181] S7: The tailings are acid-leached together with a reducing agent to remove impurities and extract nickel, cobalt, manganese and the remaining lithium to obtain qualified nickel, cobalt, manganese and lithium products.

[0182] Example 2

[0183] The difference between this embodiment and Embodiment 1 is that in S2, the calcination temperature is 450°C.

[0184] Example 3

[0185] The difference between this embodiment and embodiment 1 is that in S3, the water immersion temperature is 25°C.

[0186] Example 4

[0187] The difference between this embodiment and embodiment 1 is that in S3, the stirring speed during water immersion is 500 rpm.

[0188] Example 5

[0189] The difference between this embodiment and Embodiment 1 is that, in S6, no stabilizer (aluminum sulfate) was added during the roughing process.

[0190] Example 6

[0191] The difference between this embodiment and embodiment 1 is that in S6, the amount of kerosene and MIBC used in the roughing process is reduced. Specifically, the amount of kerosene used is 106 g / t and the amount of MIBC used is 116 g / t.

[0192] Example 7

[0193] The difference between this embodiment and Embodiment 1 is that in S6, no pH adjuster (calcium oxide) was added during the coarse selection.

[0194] Example 8

[0195] The difference between this embodiment and Embodiment 1 is that step S5 was not performed, that is, ultrasonic dispersion was not performed before flotation, and the water-leached residue was directly subjected to flotation.

[0196] Example 9

[0197] The difference between this embodiment and Embodiment 1 is that, in S6, no stabilizer (aluminum sulfate) and pH adjuster (calcium oxide) were added during the roughing process.

[0198] Example 10

[0199] The difference between this embodiment and Embodiment 1 is that, in S6, the flotation agents used in the roughing process include pH adjuster (calcium carbonate and calcium hydroxide, with a mass ratio of 1:1, 200 g / t), stabilizer (ferric chloride, 200 g / t), flocculant (sodium carboxymethyl cellulose, 500 g / t), graphite collector (diesel oil, 50 g / t), and foaming agent (pine oil, 50 g / t).

[0200] The amount of diesel fuel used in each refining process is 10g / t, and the amount of pine oil used in each refining process is 10g / t.

[0201] The amount of diesel fuel used in each scavenging process is 10g / t, and the amount of pine oil used in each scavenging process is also 10g / t.

[0202] Example 11

[0203] The difference between this embodiment and Embodiment 1 is that, in S6, the flotation agents used in the roughing process include pH adjuster (sodium carbonate and sodium hydroxide, with a mass ratio of 1:1, 4000 g / t), stabilizer (magnesium nitrate, 2000 g / t), flocculant (dextrin, 2000 g / t), graphite collector (kerosene, 500 g / t), and foaming agent (2-octanol, 400 g / t).

[0204] The amount of kerosene used in each refining process is 150g / t, and the amount of 2-octanol used in each refining process is also 150g / t.

[0205] The amount of kerosene used in each scavenging process is 150g / t, and the amount of 2-octanol used in each scavenging process is also 150g / t.

[0206] Example 12

[0207] The difference between this embodiment and embodiment 1 is that in S6, the selection is performed twice.

[0208] Example 13

[0209] The difference between this embodiment and embodiment 1 is that in S6, the selection is performed 3 times.

[0210] Example 14

[0211] The difference between this embodiment and embodiment 1 is that in S6, the number of scans is 1.

[0212] Example 15

[0213] The difference between this embodiment and Embodiment 1 is that in S2, the calcination temperature is 800℃.

[0214] Comparative Example 1

[0215] The difference between this comparative example and Example 1 is that no flocculant (starch) was added during the coarse selection in S6.

[0216] Comparative Example 2

[0217] The difference between this comparative example and Example 1 is that, in S6, no flocculant (starch) and pH adjuster (calcium oxide) were added during the roughing process.

[0218] Comparative Example 3

[0219] The difference between this comparative example and Example 1 is that, in S6, no flocculant (starch) and stabilizer (aluminum sulfate) were added during the roughing process.

[0220] Comparative Example 4

[0221] The difference between this comparative example and Example 1 is that the amount of kerosene used in the roughing process is 100g / t.

[0222] Comparative Example 5

[0223] The difference between this comparative example and Example 1 is that the amount of kerosene used in the roughing process is 600g / t.

[0224] Comparative Example 6

[0225] The difference between this comparative example and Example 1 is that the amount of MIBC used in the roughing process is 20 g / t.

[0226] Comparative Example 7

[0227] The difference between this comparative example and Example 1 is that the amount of MIBC used in the roughing process is 450 g / t.

[0228] Comparative Example 8

[0229] The difference between this comparative example and Example 1 is that the amount of corn starch used in the coarse selection process is 400g / t.

[0230] Comparative Example 9

[0231] The difference between this comparative example and Example 1 is that the amount of corn starch used in the coarse selection process is 2400 g / t.

[0232] Comparative Example 10

[0233] The difference between this comparative example and Example 1 is that the amount of calcium oxide used in the roughing process is 150 g / t.

[0234] Comparative Example 11

[0235] The difference between this comparative example and Example 1 is that the amount of calcium oxide used in the roughing process is 4200 g / t.

[0236] Comparative Example 12

[0237] The difference between this comparative example and Example 1 is that the amount of aluminum sulfate used in the roughing process is 2400 g / t.

[0238] Comparative Example 13

[0239] The difference between this comparative example and Example 1 is that the amount of kerosene used in each refining process is 0 g / t.

[0240] Comparative Example 14

[0241] The difference between this comparative example and Example 1 is that the amount of kerosene used in each refining process is 200g / t.

[0242] Comparative Example 15

[0243] The difference between this comparative example and Example 1 is that the amount of MIBC used in each selection is 0 g / t.

[0244] Comparative Example 16

[0245] The difference between this comparative example and Example 1 is that the amount of MIBC used in each selection is 200g / t.

[0246] Comparative Example 17

[0247] The difference between this comparative example and Example 1 is that the amount of kerosene used in each scavenging is 0 g / t.

[0248] Comparative Example 18

[0249] The difference between this comparative example and Example 1 is that the amount of kerosene used in each scavenging is 200g / t.

[0250] Comparative Example 19

[0251] The difference between this comparative example and Example 1 is that the amount of MIBC used in each sweep is 0 g / t.

[0252] Comparative Example 20

[0253] The difference between this comparative example and Example 1 is that the amount of MIBC used in each sweep is 200 g / t.

[0254] Comparative Example 21

[0255] The difference between this comparative example and Example 1 is that in S2, the calcination temperature is 300°C.

[0256] Comparative Example 22

[0257] The difference between this comparative example and Example 1 is that in S2, the calcination temperature is 1000°C.

[0258] Test case

[0259] The above embodiments and comparative examples were subjected to the following tests:

[0260] ① The content of Li in the raw material (battery black powder) and the leachate and leaching residue obtained in each leaching process was tested to obtain the corresponding leaching rate. The results are shown in Table 1.

[0261] ② The content of fixed carbon in the feed (battery black powder) and the tailings and concentrate obtained from the flotation process was tested, and the corresponding recovery rate was obtained. The results are shown in Table 2.

[0262] Table 1 Results of water immersion test

[0263]

[0264]

[0265] Table 2 Flotation Test Results

[0266]

[0267]

[0268]

[0269]

[0270] As shown in Table 1, the method provided in this disclosure can effectively extract Li, and the Li leaching rate is high. As shown in Table 2, the method provided in this disclosure can effectively recover graphite, with a high graphite recovery rate, and the recovered graphite product has a high fixed carbon content.

[0271] In summary, the integrated whole-chain recycling method for lithium and graphite in waste batteries provided in this disclosure is simple and easy to implement, and can effectively recycle lithium and graphite in waste batteries with high recovery rates for both lithium and graphite, thus avoiding resource waste.

[0272] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

[0273] Industrial applicability

[0274] The method for recycling lithium and graphite from waste batteries through a complete integrated recycling chain provided in this disclosure is simple and easy to implement. It can effectively recycle lithium and graphite from waste batteries with high recovery rates for both lithium and graphite, and the recovered graphite has a high fixed carbon content, thus avoiding resource waste.

Claims

1. A method for the integrated recycling of lithium and graphite from waste batteries across the entire supply chain, characterized in that, Includes the following steps: The battery black powder obtained from waste batteries is roasted and extracted by water leaching to extract lithium, and the water leaching residue is floated. The water immersion temperature is 25℃-90℃; the water immersion is carried out under stirring conditions; the stirring speed during the water immersion process is 500rpm-2000rpm; Flotation includes: using a flotation agent to perform a roughing process on the water-leached residue to obtain a roughing froth and a roughing slurry; and performing at least one cleaning process on the roughing froth to finally obtain a carbon-containing concentrate. The flotation agent consists of a graphite collector, a modifier, and a frother; the modifier consists of a flocculant, a pH adjuster, and a stabilizer. The graphite collector is selected from at least one of kerosene and diesel oil; the flocculant is selected from at least one of starch, sodium carboxymethyl cellulose, and dextrin; the foaming agent is selected from at least one of methyl isobutyl methanol, pine oil, and 2-octanol; the pH adjuster is selected from at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate, and sodium hydroxide; and the stabilizer is selected from at least one of aluminum sulfate, aluminum nitrate, aluminum chloride, polyaluminum chloride, ferric sulfate, ferric nitrate, ferrous sulfate, ferric chloride, ferrous chloride, magnesium nitrate, magnesium chloride, and magnesium sulfate. The dosage of the graphite collector is 50 g / t-500 g / t; the dosage of the flocculant is 500 g / t-2000 g / t; the dosage of the foaming agent is 50 g / t-400 g / t; the dosage of the pH adjuster is 200 g / t-4000 g / t; and the dosage of the stabilizer is 200 g / t-2000 g / t.

2. The method according to claim 1, characterized in that, The number of selections is n, where n≥2 and is an integer; during the first n-1 selections, each selection yields the n-1th selected foam material and the n-1th selected middlings; the n-1th selected foam material is used as the raw material to be selected for the nth selection.

3. The method according to claim 2, characterized in that, When n=2, the middlings from the first finest ...

4. The method according to claim 3, characterized in that, When n=2, the ore obtained from the second refining process is returned to the first refining process as raw material to be refined.

5. The method according to claim 2, characterized in that, When n≥3, the ore obtained from the (n-1)th refining process is returned as raw material to the (n-2)th refining process.

6. The method according to claim 2, characterized in that, The ore obtained from the nth refining process is returned as raw material to the (n-1)th refining process.

7. The method according to claim 4 or 5, characterized in that, When selected middlings are returned to the second selection process as raw materials, the foam material from the first selection and the middlings from the third selection are combined and ground and scrubbed before the second selection.

8. The method according to claim 7, characterized in that, The wiping time is 2-15 minutes.

9. The method according to claim 1, characterized in that, Each selection process uses separate selection agents, including graphite collectors and foaming agents.

10. The method according to claim 9, characterized in that, The graphite collector used in each refining process includes at least one of kerosene and diesel oil; And / or, the foaming agent used in each selection process includes at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

11. The method according to claim 9 or 10, characterized in that, The amount of graphite collector used in each beneficiation process is 0-150 g / t; and / or, the amount of foaming agent used in each beneficiation process is 0-150 g / t.

12. The method according to claim 1, characterized in that, Flotation also includes: scavenging the roughing slurry at least once to finally obtain carbon-containing tailings.

13. The method according to claim 12, characterized in that, The number of scavenging operations is m, where m ≥ 2 and is an integer; during the first m-1 scavenging operations, the remaining slurry from the m-1th scavenging operation and the ore in the foam from the m-1th scavenging operation are obtained after each scavenging operation; the remaining slurry from the m-1th scavenging operation is used as the raw material to be selected for the mth scavenging operation.

14. The method according to claim 13, characterized in that, When m=2, the first scavenged froth ore obtained from the first scavenging is returned to the roughing process as raw material to be selected.

15. The method according to claim 13 or 14, characterized in that, When m=2, the ore from the second scavenging froth obtained from the second scavenging is returned to the first scavenging process as raw material to be selected.

16. The method according to claim 13, characterized in that, When m≥3, the froth ore obtained from the (m-1)th scavenging is returned as raw material to the (m-2)th scavenging process.

17. The method according to claim 13 or 16, characterized in that, The froth middlings obtained from the m-th scavenging is returned as raw material to the (m-1)-th scavenging process.

18. The method according to claim 12, characterized in that, Each scavenging process uses a separate scavenging agent consisting of a graphite collector and a foaming agent.

19. The method according to claim 18, characterized in that, The graphite collector used in each scavenging process includes at least one of kerosene and diesel oil; And / or, the foaming agent used in each scavenging process includes at least one of methyl isobutyl methanol, pine oil, and 2-octanol.

20. The method according to claim 18 or 19, characterized in that, The amount of graphite collector used in each scavenging process is 0-150 g / t; and / or, the amount of frother used in each scavenging process is 0-150 g / t.

21. The method according to claim 12, characterized in that, The number of coarse selections is 1, the number of fine selections is 4, and the number of sweep selections is 2.

22. The method according to claim 1, characterized in that, The main sources of the battery black powder include lithium-containing cathode materials and graphite-containing anode materials.

23. The method according to claim 22, characterized in that, The sources of the battery black powder also include at least one of current collectors and battery impurities.

24. The method according to claim 23, characterized in that, The current collector includes copper foil or aluminum foil.

25. The method according to claim 1, characterized in that, By mass percentage, the battery black powder contains 30%-55% carbon, 3%-7% Li, 10%-35% Ni, 2%-5% Co, 2%-5% Mn, 0.055-1% Cu, 0.05%-1% Al, and 0.05%-1% Fe.

26. The method according to claim 1, characterized in that, The preparation of the battery black powder includes: discharging, crushing, pyrolyzing and screening waste batteries.

27. The method according to claim 1, characterized in that, Calcination includes at least one of the following characteristics: Feature 1: Firing temperature is 400℃-800℃; Feature 2: Calcination time is 30 min - 180 min; Feature 3: The roasting is carried out in an oxygen-free environment.

28. The method according to claim 27, characterized in that, An oxygen-free environment is provided by nitrogen or an inert gas.

29. The method according to claim 1, characterized in that, Lithium extraction by water leaching includes a water leaching process, which includes at least one of the following characteristics: Feature 1: The solid-liquid ratio during water immersion is 1:3-1:10; Feature 2: The immersion time is 30-120 minutes.

30. The method according to claim 29, characterized in that, Lithium extraction by water leaching also includes a lithium extraction process, which involves evaporating the leaching solution obtained from the water leaching process.

31. The method according to claim 30, characterized in that, Evaporation is carried out using a water bath evaporation method.

32. The method according to claim 31, characterized in that, The temperature for water bath evaporation is 80℃-100℃.

33. The method according to claim 1, characterized in that, Prior to flotation, the water-leached residue is dispersed.

34. The method according to claim 33, characterized in that, The dispersion method is ultrasonic dispersion.

35. The method according to claim 34, characterized in that, Ultrasonic dispersion includes at least one of the following characteristics: Feature 1: Ultrasonic dispersion is carried out by mixing the water-impregnated residue with water at a liquid-to-solid ratio of 1:3 to 1:10; Feature 2: Ultrasonic stirring intensity is 300rpm-1000rpm; Feature 3: The ultrasonic dispersion time is 5 min-20 min.

36. The method according to claim 1, characterized in that, Following flotation, the process also includes post-processing of the flotation tailings products; Post-treatment includes acid leaching, impurity removal, and extraction.

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