CN116723896A

CN116723896A - A full-chain integrated method for recycling lithium and graphite in used batteries

Info

Publication number: CN116723896A
Application number: CN202380008699.3A
Authority: CN
Inventors: 张鹏; 饶金山; 李海森; 孟志远; 阮丁山; 李长东
Original assignee: Hunan Brunp Recycling Technology Co Ltd; Guangdong Brunp Recycling Technology Co Ltd
Current assignee: Hunan Brunp Recycling Technology Co Ltd; Guangdong Brunp Recycling Technology Co Ltd
Priority date: 2023-04-18
Filing date: 2023-04-18
Publication date: 2023-09-08
Also published as: WO2024216488A1

Abstract

The invention discloses a method for integrally recycling lithium and graphite in waste batteries through a full chain, and belongs to the technical field of battery recycling. Roasting battery black powder obtained from waste batteries, leaching lithium with water, and floating water leaching residues; wherein, the flotation includes: carrying out primary roughing on the water leaching slag by adopting a flotation agent to obtain roughing foam materials and roughing liquid materials; carrying out at least one-time concentration on the roughing foam material to finally obtain carbon-containing concentrate; flotation agents include graphite collectors, flocculants, and frothers. The method is simple and easy to implement, lithium and graphite in the waste batteries can be effectively recycled, the recovery rates of the lithium and the graphite are high, and resource waste is avoided.

Description

Method for integrally recycling lithium and graphite in waste batteries through full chain

Technical Field

The disclosure relates to the technical field of battery recovery, in particular to a method for integrally recovering lithium and graphite in waste batteries through a full chain.

Background

With the rapid development of new energy industry, the price of battery-grade lithium carbonate has increased from 5 ten thousand yuan/ton at the beginning of 2021 to 30 ten thousand yuan/ton in 3 months of 2023, during which the price exceeds 55 ten thousand yuan/ton.

At present, the recovery process of the waste ternary lithium battery is mainly divided into disassembly and hydrometallurgy and pyrometallurgy. The wet metallurgical process mainly comprises leaching battery black powder by adding a reducing agent into organic acid or inorganic acid, and has the problem that the recovery rate of lithium is generally lower than 80 percent, and graphite under the process is treated as hazardous waste, so that a great amount of resource waste is caused. The pyrogenic process has the problems of high energy consumption, failure in recovery of lithium and graphite, and the like.

The valuable metals and the graphite in the waste batteries are recovered, so that the valuable metals and the graphite in the batteries are returned to the battery end again, the full-component recovery is realized, the full-chain integrated industrial garden is built, the cost is reduced, the efficiency is improved, and the resource waste is avoided. However, no method capable of effectively recycling lithium and graphite from waste batteries at the same time is currently known.

In view of this, the present disclosure is specifically proposed.

Disclosure of Invention

The method is simple and easy to implement, can effectively recycle the lithium and the graphite in the waste batteries, has higher recovery rates of the lithium and the graphite, and avoids resource waste.

In order to achieve the above object of the present disclosure, the following technical solutions may be adopted:

The disclosure includes providing a method for integrally recovering lithium and graphite in waste batteries by using a full chain, comprising the following steps:

roasting and leaching lithium from battery black powder obtained from waste batteries, and floating water leaching residues;

wherein, the flotation includes: carrying out primary roughing on the water leaching slag by adopting a flotation agent to obtain roughing foam materials and roughing liquid materials; carrying out at least one-time concentration on the roughing foam material to finally obtain carbon-containing concentrate;

the flotation agent comprises a graphite collector, a regulator and a foaming agent; the conditioning agent includes a flocculant.

In some embodiments of the present disclosure, the graphite collector comprises at least one of kerosene and diesel oil;

and/or the flocculant comprises at least one of starch, sodium carboxymethyl cellulose and dextrin;

and/or the foaming agent comprises at least one of methyl isobutyl carbinol, pinitol oil and sec-octanol.

In some embodiments of the present disclosure, the graphite collector is used in an amount of 50g/t to 500g/t; and/or the flocculant is used in an amount of 500g/t-2000g/t; and/or the amount of the foaming agent is 50g/t-400g/t.

In some embodiments of the present disclosure, the adjusting agent further comprises at least one of a pH adjuster and a stabilizer.

In some embodiments of the present disclosure, the pH adjuster comprises at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate, and sodium hydroxide;

and/or the stabilizer comprises 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.

In some embodiments of the present disclosure, the pH adjustor is used in an amount of 200g/t to 4000g/t, and/or the stabilizer is used in an amount of 200g/t to 2000g/t.

In some embodiments of the present disclosure, the beneficiation number is n times, n being greater than or equal to 2 and being an integer; in the first n-1 times of fine selection process, respectively obtaining the n-1 times of fine selection foam materials and the n-1 times of fine selection middlings after each fine selection; the (n-1) th beneficiation foam is used as a candidate material for the (n-th beneficiation).

In some embodiments of the present disclosure, when n=2, the 1 st beneficiated middlings resulting from the 1 st beneficiation are returned to the rougher process as the feedstock to be beneficiated.

In some embodiments of the present disclosure, when n=2, the 2 nd beneficiated middlings resulting from the 2 nd beneficiation are returned to the 1 st beneficiation process as the feedstock to be beneficiated.

In some embodiments of the present disclosure, when n.gtoreq.3, the (n-1) th beneficiated middlings resulting from the (n-1) th beneficiation are returned to the (n-2) th beneficiation process as a candidate material.

In some embodiments of the present disclosure, the nth beneficiated middlings resulting from the nth beneficiation are returned to the nth beneficiation process as a feedstock to be beneficiated.

In some embodiments of the present disclosure, when beneficiated middlings are returned to the 2 nd beneficiation process as a candidate, the 1 st beneficiation froth is combined with the 3 rd beneficiated middlings for grinding scrubbing prior to the 2 nd beneficiation.

In some embodiments of the present disclosure, the scrubbing time is from 2 minutes to 15 minutes.

In some embodiments of the present disclosure, the beneficiating agent used for each beneficiation independently comprises a graphite collector and a frothing agent.

In some embodiments of the present disclosure, the graphite collector used in each beneficiation process comprises at least one of kerosene and diesel;

and/or the foaming agent used in each beneficiation process comprises at least one of methyl isobutyl carbinol, pinitol oil, and sec-octanol.

In some embodiments of the present disclosure, the amount of graphite collector used in each beneficiation process is 0-150g/t; and/or the amount of foaming agent used per beneficiation process is 0-150g/t.

In some embodiments of the present disclosure, the flotation further comprises: and (3) scavenging the roughing slurry at least once to finally obtain the carbon-containing tailings.

In some embodiments of the present disclosure, the number of sweeps is m times, m is greater than or equal to 2 and is an integer; in the first m-1 scavenging process, m-1 scavenging residual slurry and m-1 scavenging foam middling are respectively obtained after each scavenging; and taking the m-1 th scavenging residual slurry as a raw material to be selected for the m-th scavenging.

In some embodiments of the present disclosure, when m=2, the 1 st scavenger foam middlings resulting from the 1 st scavenger are returned to the rougher process as the raw material to be selected.

In some embodiments of the present disclosure, when m=2, the 2 nd scavenger foam middlings resulting from the 2 nd scavenger are returned to the 1 st scavenger process as the raw material to be selected.

In some embodiments of the present disclosure, when m is greater than or equal to 3, the m-1 th scavenger foam middling obtained from the m-1 th scavenger is returned to the m-2 th scavenger process as a raw material to be selected.

In some embodiments of the present disclosure, the mth scavenger foam middlings resulting from the mth scavenger are returned to the mth-1 scavenger process as the feedstock to be selected.

In some embodiments of the present disclosure, the scavenger used for each scavenger independently includes a graphite collector and a frother.

In some embodiments of the present disclosure, the graphite collector used in each scavenging process comprises at least one of kerosene and diesel;

And/or the foaming agent used in each scavenging process comprises at least one of methyl isobutyl carbinol, pinitol oil and sec-octanol.

In some embodiments of the present disclosure, the amount of graphite collector used per sweep is 0-150g/t; and/or the amount of foaming agent used in each scavenging process is 0-150g/t.

In some embodiments of the present disclosure, the roughing number is 1, the refining number is 4, and the scavenging number is 2.

In some embodiments of the present disclosure, the primary sources of battery black powder include a positive electrode material comprising lithium and a negative electrode material comprising graphite.

In some embodiments of the present disclosure, the source of battery black powder further comprises at least one of a current collector and battery impurities.

In some embodiments of the present disclosure, the current collector comprises copper foil or aluminum foil.

In some embodiments of the present disclosure, the battery black powder has a fixed carbon content of 30% -55%, a Li content of 3% -7%, a Ni content of 10% -35%, a Co content of 2% -5%, a Mn content of 2% -5%, a Cu content of 0.055-1%, an Al content of 0.05% -1%, and a Fe content of 0.05% -1% by mass%.

In some embodiments of the present disclosure, the preparation of the battery black powder includes: discharging, crushing, cracking and screening the waste batteries.

In some embodiments of the present disclosure, firing includes at least one of the following features:

characteristic one: the roasting temperature is 400-800 ℃;

and the second characteristic is: roasting for 30-180 min;

and (3) the following characteristics: the calcination is performed in an oxygen-free environment.

In some embodiments of the present disclosure, the anaerobic environment is provided by nitrogen or an inert gas.

In some embodiments of the present disclosure, leaching lithium with water includes a water leaching process, the water leaching including at least one of the following features:

characteristic one: the solid-liquid ratio of water immersion is 1:3-1:10;

and the second characteristic is: the temperature of water immersion is 25-90 ℃;

and (3) the following characteristics: the water immersion time is 30min-120min;

and four characteristics: the water immersion is carried out under stirring.

In some embodiments of the present disclosure, the agitation speed during water immersion is 500rpm to 2000rpm.

In some embodiments of the present disclosure, the water leaching of lithium further comprises a lithium extraction process, the lithium extraction mode comprising evaporating a water leaching solution obtained from the water leaching process.

In some embodiments of the present disclosure, the evaporation is performed by means of water bath evaporation.

In some embodiments of the present disclosure, the temperature of the water bath evaporation is 80 ℃ to 100 ℃.

In some embodiments of the present disclosure, prior to flotation, dispersing the water leaching residue is further included.

In some embodiments of the present disclosure, the dispersion form is ultrasonic dispersion.

In some embodiments of the present disclosure, the ultrasonic dispersion includes at least one of the following features:

characteristic one: the ultrasonic dispersion is carried out after water leaching slag and water are mixed according to the liquid-solid ratio of 1:3-1:10;

and the second characteristic is: the ultrasonic stirring intensity is 300rpm-1000rpm;

and (3) the following characteristics: the ultrasonic dispersion time is 5min-20min.

In some embodiments of the present disclosure, after flotation, further comprising post-treating the flotation tailings product;

the post-treatment comprises acid leaching, impurity removal and extraction.

The method obtains higher Li leaching rate by roasting and leaching the battery black powder obtained from the waste batteries. The foaming agent used in the flotation process can increase the foam amount by carrying out a specific flotation process on the obtained water leaching slag, so that the flotation is facilitated; the flocculant can act on the water leaching slag to flocculate the water leaching slag, and then the graphite is effectively captured by the graphite collector.

The method is simple and easy to implement, lithium and graphite in the waste batteries can be effectively recycled, the recovery rates of the lithium and the graphite are high, and resource waste is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present disclosure and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is an overall flow chart of a method for full chain integrated recovery of lithium and graphite from spent batteries provided by the present disclosure;

fig. 2 is a flow chart of a flotation process in the method for full chain integrated recovery of lithium and graphite in waste batteries provided by the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The method for integrally recycling lithium and graphite in waste batteries by using the full chain provided by the disclosure is specifically described below.

Referring to fig. 1 and 2, the disclosure provides a method for integrally recovering lithium and graphite in waste batteries by using a full chain, comprising the following steps: roasting and leaching lithium from battery black powder obtained from waste batteries, and floating water leaching residues.

For reference, the main sources of battery black powder may include a positive electrode material containing lithium and a negative electrode material containing graphite.

For example, the lithium-containing cathode material may include at least one of a binary cathode material, a ternary cathode material, a quaternary cathode material, and a more complex cathode material.

In some embodiments, the metallic elements contained in the binary positive electrode material may be, by way of example and not limitation, nickel and cobalt; the elements contained in the ternary positive electrode material may be, by way of example and not limitation, nickel, cobalt, manganese; the elements contained in the quaternary positive electrode material may be, by way of example and not limitation, nickel, cobalt, manganese, and aluminum.

Further, the source of the battery black powder may further include at least one of a current collector and battery impurities.

The current collector may include, for example, copper foil or aluminum foil. The battery impurities may include, for example, scrap iron or the like.

As a reference, the fixed carbon content in the battery black powder may be 30% -55% (e.g., 30%, 32%, 35%,. 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, etc.), the Li content may be 3% -7% (e.g., 3%, 3.5%, 4%, 4.5%, 5.5%, 6%, 6.5%, 7%, etc.), the Ni content may be 10% -35% (e.g., 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc.), the Co content may be 2% -5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, etc.), the Mn content may be 2% -5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, etc.), the Cu content may be 0.055-1% (e.g., 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, or 35%, etc.), the Co content may be 2% -5% (e.8%, 0.05%, 0% or 5%, etc.), the Mn content may be 2% -5% (e.0.05%, 0.05%, 0% or 0.05%, 0% or 1% or 0% of the like).

The chemical composition and content of the battery black powder obtained from the waste batteries are not limited to the above ranges, and may be determined as appropriate.

In some alternative embodiments, the preparation of the battery black powder may include: discharging, crushing, cracking and screening the waste batteries.

The above-mentioned discharging, crushing and cracking can be performed in a conventional manner, and will not be described in detail herein.

As a reference, in the firing process, the firing temperature may be 400℃to 800℃such as 400℃to 450℃to 500℃to 550℃to 600℃to 650℃to 700℃to 750℃or 800℃or any other value within the range of 400℃to 800 ℃.

The calcination time may be 30min-180min, such as 30min, 50min, 80min, 100min, 120min, 150min or 180min, or any other value within 30min-180 min.

In some specific alternative embodiments, the firing temperature may be 500 ℃ and the firing time may be 180 minutes.

In some preferred embodiments, the firing is performed in an oxygen-free environment. The oxygen-free environment may be provided by nitrogen or an inert gas such as argon or helium, etc.

It should be noted that, in the roasting process, no additive is adopted, and the battery black powder is directly roasted in an oxygen-free environment, so that other impurity ions are not introduced, and the subsequent impurity removal is facilitated. In addition, through roasting treatment, a binder (such as PVDF) in the positive electrode active material can be removed, so that the difference of the surface floatability of the positive electrode active material and the negative electrode active material is greatly improved, and the flotation separation of the positive electrode material and the negative electrode material is facilitated.

For reference, leaching lithium by water includes a water leaching process, wherein the solid-to-liquid ratio of the water leaching process can be 1:3-1:10, such as 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, and the like, and can be any other value in the range of 1:3-1:10.

The water immersion temperature may be 25℃to 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 alternative embodiments, the temperature of the water immersion is from 25 ℃ to 90 ℃.

The water immersion time can be 30min-120min, such as 30min, 50min, 80min, 100min or 120min, or any other value within 30min-120 min.

In some preferred embodiments, the water leaching is performed under stirring conditions to enhance the leaching effect and facilitate the enhancement of the leaching rate of lithium.

Illustratively, the agitation speed during the water immersion may be 500rpm-2000rpm, such as 500rpm, 800rpm, 1000rpm, 1200rpm, 1500rpm, 1800rpm, 2000rpm, or the like.

The above-mentioned water immersion process may be performed only 1 time, or may be repeated as many times as necessary.

In some specific alternative embodiments, the water to solid ratio may be 1:5, the water soak temperature may be 80 ℃, the water soak time may be 60 minutes, the stirring speed may be 1500rpm, and the water soak times may be 2 times.

On the one hand, the leaching rate of lithium is improved by adopting higher stirring intensity and higher temperature in the water leaching process, and on the other hand, the surface exposure of the anode and cathode active materials is more complete under high-intensity stirring, so that the surface difference of the anode and cathode materials is further increased.

Further, the water leaching lithium extraction process also comprises a lithium extraction process, wherein the lithium extraction mode comprises evaporating water leaching liquid obtained in the water leaching process, and can be also understood as evaporating and precipitating lithium.

For example, the evaporation may be performed by evaporation in a water bath.

The water bath evaporation temperature may be 80-100deg.C, such as 80deg.C, 85deg.C, 90deg.C, 95deg.C or 100deg.C. Until the evaporation of the water is complete.

In some specific alternative embodiments, the temperature of the water bath evaporation is 90 ℃.

On the support, the lithium is leached by water, so that the lithium-containing material with high purity can be directly obtained, and the recovery rate is more than 80%. The rest lithium enters the subsequent acid leaching process through the flotation process, and the recovery rate of the lithium in the final whole process is more than or equal to 93 percent.

In the present disclosure, the water leaching residue may also be dispersed prior to flotation.

For reference, the dispersion form may be ultrasonic dispersion.

In some embodiments, ultrasonic dispersion may be performed after mixing the water-soaked slag with water in 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, etc.).

The intensity of ultrasonic agitation may be 300rpm to 1000rpm, such as 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm, 1000rpm, or the like, and may be any other value within the range of 300rpm to 1000 rpm.

The ultrasonic dispersion time can be 5min-20min, such as 5min, 8min, 10min, 12min, 15min, 18min or 20min, or any other value within 5min-20 min.

In some specific alternative embodiments, the ultrasonic dispersion may have a solids to liquid ratio of 1:5, the agitation intensity may be 500rpm, and the dispersion time may be 10 minutes.

The dispersion of the water leaching slag before flotation is more beneficial to the subsequent flotation and graphite separation.

In the present disclosure, flotation may be performed in a flotation machine.

As a reference ground, flotation includes: carrying out primary roughing on the water leaching slag by adopting a flotation agent to obtain roughing foam materials and roughing liquid materials; and (3) carrying out concentration on the roughing foam material at least once to finally obtain the carbon-containing concentrate.

The flotation agents used in the rougher process may include graphite collectors, conditioning agents, and frothers; the conditioning agent includes a flocculant.

The graphite collector may include, by way of example and not limitation, at least one of kerosene and diesel fuel. The flocculant may include, by way of example and not limitation, at least one of starch (preferably soluble starch, such as corn starch, etc.), sodium carboxymethyl cellulose, and dextrin. The foaming agent may include, by way of example and not limitation, at least one of methyl isobutyl carbinol (MIBC), pinitol oil, and sec-octanol.

In some embodiments, the amount of graphite collector used in the roughing process may be 50g/t to 500g/t, such as 50g/t, 80g/t, 100g/t, 150g/t, 200g/t, 250g/t, 300g/t, 350g/t, 400g/t, 450g/t, 500g/t, etc., and may be any other value in the range of 50g/t to 500 g/t.

If the dosage of the graphite collecting agent is lower than 50g/t, the quality of graphite products is not facilitated, and the recovery rate is low; if the content is higher than 500g/t, the carbon content of the graphite product is not easy to fix.

In the roughing process, the flocculant can be used in an amount of 500g/t-2000g/t, such as 500g/t, 800g/t, 1000g/t, 1200g/t, 1500g/t, 1800g/t or 2000g/t, etc., and can also be used in any other value within the range of 500g/t-2000 g/t.

If the dosage of the flocculant is lower than 500g/t, the quality of the graphite product is not facilitated; if the concentration is higher than 2000g/t, the recovery rate of graphite is low.

The amount of the foaming agent used in the roughing process may be 50g/t to 400g/t, such as 50g/t, 100g/t, 150g/t, 200g/t, 250g/t, 300g/t, 350g/t or 400g/t, etc., and may be any other value within the range of 50g/t to 400 g/t.

If the consumption of the foaming agent is lower than 50g/t, the recovery rate of the graphite product is not facilitated; if the content is higher than 400g/t, the quality of the graphite product is not good.

Further, the regulator used in the roughing process may further include at least one of a pH regulator and a stabilizer.

The pH adjustor can include, by way of example and not limitation, at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate, and sodium hydroxide.

The stabilizer may include, by way of example and not limitation, 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.

In some embodiments, the pH adjustor can be used in an amount of 200g/t to 4000g/t, such as 200g/t, 500g/t, 800g/t, 1000g/t, 1500g/t, 2000g/t, 2500g/t, 3000g/t, 3500g/t, 4000g/t, etc., or any other value in the range of 200g/t to 4000g/t during roughing.

If the dosage of the pH regulator is lower than 200g/t, the quality of the graphite product is not facilitated; if the ratio is higher than 4000g/t, the quality of the graphite product is not good.

The amount of the stabilizer used in the roughing process may be 200g/t-2000g/t, such as 200g/t, 500g/t, 800g/t, 1000g/t, 1200g/t, 1500g/t, 1800g/t, 2000g/t, etc., or any other value within the range of 200g/t-2000 g/t.

If the dosage of the stabilizer is lower than 200g/t, the recovery rate of the graphite product is not facilitated; if the content is higher than 2000g/t, the quality of the graphite product is not good.

In some specific alternative embodiments, the graphite collector used in the roughing process is kerosene, the flocculant is starch, the foamer is MIBC, the pH regulator is calcium oxide, and the stabilizer is aluminum sulfate; wherein, the dosage of kerosene is 212g/t, the dosage of starch is 1500g/t, the dosage of MIBC is 174g/t, the dosage of calcium oxide is 2000g/t, and the dosage of aluminum sulfate is 1000g/t.

On the basis, the principle of the roughing process comprises: the foaming agent can increase the foam quantity, which is beneficial to flotation; the flocculant can act on water leaching slag (such as cobalt-manganese product) to flocculate the slag, and graphite is effectively captured by a graphite collector. The pH regulator can be matched with flocculant to improve flocculation effect, the stabilizer can increase foam half-life, the foam stabilizer is increased, and the consumption of foaming agent is reduced.

Further, the foam obtained by the rough concentration is carefully selected.

The preset number of beneficiation is n times, n is more than or equal to 2 and is an integer, for example, n can be 1, or can be 2, 3, 4 or more.

In the first n-1 times of fine selection process, respectively obtaining the n-1 times of fine selection foam materials and the n-1 times of fine selection middlings after each fine selection; the (n-1) th beneficiation foam is used as a candidate material for the (n) (i.e., next beneficiation).

When n=2, the 1 st beneficiated middlings obtained from the 1 st beneficiation can also be returned to the roughing process as the raw materials to be beneficiated. Further, the 2 nd concentrating middlings obtained by the 2 nd concentrating can be used as raw materials to be selected and returned to the 1 st concentrating process.

When n is more than or equal to 3, the (n-1) th beneficiated middling obtained by the (n-1) th beneficiation can be used as a raw material to be beneficiated and returned to the (n-2) th beneficiation process. Further, the selected middlings obtained in the nth selection can be used as raw materials to be selected and returned to the nth-1 selection process.

The recovery rate can be improved by adopting a closed-circuit concentration mode for concentration, namely, middlings obtained by concentration are not discharged.

In some embodiments, when the beneficiated middlings are returned to the 2 nd beneficiation process as the candidate material, the 1 st beneficiation froth is combined with the 3 rd beneficiated middlings (i.e., the 3 rd beneficiated middlings resulting from the 3 rd beneficiation) prior to performing the 2 nd beneficiation.

The scrubbing time may be, for example, 2min-15min, such as 2min, 5min, 8min, 10min, 12min, 15min, etc. In some specific alternative embodiments, the scrubbing time may be 5 minutes.

The grinding and scrubbing can be performed in a vertical mill or a ball mill.

The fresh surface of the graphite can be produced by grinding and scrubbing, which is beneficial to improving the fixed carbon content of the graphite product.

In the present disclosure, the beneficiating agent used for each beneficiation can independently comprise a graphite collector and a frothing agent.

The graphite collector used in each beneficiation process can comprise at least one of kerosene and diesel fuel by way of example and not limitation. The foaming agent used in each beneficiation process can include, by way of example and not limitation, at least one of methyl isobutyl carbinol, pinitol oil, and sec-octanol.

In some embodiments, the amount of graphite collector used in each beneficiation process can be in the range of 0-150g/t, such as 0g/t, 5g/t, 10g/t, 20g/t, 50g/t, 80g/t, 100g/t, 120g/t, 150g/t, etc., as well as any other value in the range of 0-150 g/t.

The amount of foaming agent used in each beneficiation process may be 0-150g/t, such as 0g/t, 5g/t, 10g/t, 20g/t, 50g/t, 80g/t, 100g/t, 120g/t, 150g/t, etc., or any other value in the range of 0-150 g/t.

In some particular alternative embodiments, the graphite collector used in each beneficiation process may be kerosene and the frother may be MIBC. Taking 4 times of selection as an example, the dosage of kerosene used in the 1 st time of selection can be 53g/t, and the dosage of MIBC can be 58g/t; the amount of kerosene used for the 2 nd selection can be 53g/t, and the amount of MIBC can be 58g/t; the amount of kerosene used for the 3 rd selection can be 53g/t, and the amount of MIBC can be 29g/t; the amount of kerosene used for the 4 th beneficiation may be 26.5g/t and the amount of MIBC may be 0g/t.

Further, the flotation may further include: and (3) scavenging the roughing slurry at least once to finally obtain the carbon-containing tailings.

The preset number of times of scavenging is m times, m is more than or equal to 2 and is an integer, for example, m can be 1, or can be 2, 3, 4 or more.

In the first m-1 scavenging process, m-1 scavenging residual slurry and m-1 scavenging foam middling are respectively obtained after each scavenging; and taking the m-1 th scavenging residual slurry as a raw material to be selected for the m-th scavenging (namely, the next scavenging).

When m=2, the 1 st scavenging foam middlings obtained by 1 st scavenging can be returned to the roughing process as the raw materials to be selected. Further, the foam middlings of the 2 nd scavenging obtained by the 2 nd scavenging can be used as the raw materials to be selected and returned to the 1 st scavenging process.

When m is more than or equal to 3, the m-1 th scavenging foam middling obtained by m-1 th scavenging can be used as a raw material to be selected and returned to the m-2 th scavenging process. Further, the m-th scavenging foam middling obtained by m-th scavenging can be used as a raw material to be selected and returned to the m-1-th scavenging process.

In the present disclosure, the scavenger used for each scavenger may independently include a graphite collector and a foaming agent.

The graphite collector used in each sweep process may include, by way of example and not limitation, at least one of kerosene and diesel fuel. The foaming agent used in each of the scavenging processes may include, by way of example and not limitation, at least one of methyl isobutyl carbinol, pinitol oil, and sec-octanol.

In some embodiments, the amount of graphite collector used in each sweep may be from 0 to 150g/t, such as 0g/t, 5g/t, 10g/t, 20g/t, 50g/t, 80g/t, 100g/t, 120g/t, 150g/t, etc., and may be any other value in the range of from 0 to 150 g/t.

The amount of foaming agent used in each scavenging process may be 0-150g/t, such as 0g/t, 5g/t, 10g/t, 20g/t, 50g/t, 80g/t, 100g/t, 120g/t, 150g/t, etc., or any other value in the range of 0-150 g/t.

If the dosage of the graphite collecting agent used in each scavenging process is higher than 150g/t, the quality of graphite products is not facilitated; if the consumption of the foaming agent used in each scavenging process is higher than 150g/t, the quality of the graphite product is not good.

In some particular alternative embodiments, the graphite collector used in each sweep may be kerosene and the frother may be MIBC. Taking 2 times of scavenging as an example, the dosage of kerosene used in the 1 st scavenging can be 106g/t, and the dosage of MIBC can be 58g/t; the amount of kerosene used for the 2 nd sweep may be 53g/t and the amount of MIBC may be 58g/t.

In some specific alternative embodiments of the present disclosure, the roughing number is 1, the beneficiating number is 4, and the scavenging number is 2, i.e., the corresponding flotation process is a "one roughing four fine two sweep" process.

On the way, the flotation process adopts a flocculation flotation process, and the flotation effect of separating graphite by flotation is further improved by adding a medicament to act on water leaching residues (such as cobalt-manganese products) to flocculate and inhibit floatability of the water leaching residues. The stabilizing agent is added during flotation, so that the stabilizing agent has a certain stabilizing effect on flotation foam, the half life of the foam can be increased, and the dosage of the graphite collector and the foaming agent can be reduced.

Further, after flotation, the flotation tailings product may also be subjected to post-treatment, such as for example acid leaching, impurity removal, extraction and the like.

It should be noted that, the specific processing procedures and conditions related to the above post-processing may refer to corresponding conventional operations, and are not described herein in detail.

The features and capabilities of the present disclosure are described in further detail below in connection with the examples.

Example 1

Referring to fig. 1 and 2, the embodiment provides a method for integrally recycling lithium and graphite in waste batteries by using a full chain, which comprises the following steps:

s1: and discharging, crushing, cracking and screening the waste ternary lithium batteries to obtain battery black powder (namely ore feeding).

The battery black powder comprises a nickel cobalt lithium manganate ternary positive electrode material, a graphite negative electrode material and a current collector which are copper foil and aluminum foil, and battery impurities (scrap iron).

In the battery black powder, the fixed carbon content is 44.10%, the Li content is 4.04%, the Ni content is 26.80%, the Co content is 3.39%, the Mn content is 2.56%, the Cu content is 0.11%, the Al content is 0.10% and the Fe content is 0.10% by mass percent.

S2: and roasting the battery black powder in an oxygen-free environment.

The anaerobic environment is provided by nitrogen, the roasting temperature is 550 ℃, and the roasting time is 180min.

S3: placing the roasted material into a container for water leaching under the following conditions: the solid-liquid ratio is 1:5, the water temperature is 80 ℃, the stirring rotation speed is 1500rpm, the water immersion time is 60min, and the water immersion times are 2 times.

S4, evaporating and precipitating lithium: and (3) evaporating and concentrating the lithium carbonate in a water bath for the water leaching solution, and heating in the water bath until the water evaporation is complete.

S5: and (3) ultrasonic dispersion: filtering the material obtained in the step S4, putting the filtered water leaching residues into a container, adding pure water until the liquid-solid ratio is 1:10, stirring intensity is 500rpm, and ultrasonic dispersion time is 10min.

S6: flotation operation: the ultrasonic dispersed materials are added into a flotation machine, and the flotation adopts a 'one coarse four fine two sweep' closed-circuit flow.

The coarse-dressing foam obtained by the coarse dressing is subjected to 1 st dressing to obtain 1 st dressing foam and 1 st dressing middling (marked as middling 3). The middlings 3 are used as raw materials to be selected and returned to the roughing process.

The 1 st beneficiated froth is subjected to a 2 nd beneficiation process to obtain a 2 nd beneficiated froth and a 2 nd beneficiated middlings (designated middlings 4). The middling 4 is returned to the 1 st concentration process as a raw material to be selected.

The 2 nd beneficiation froth was subjected to a 3 rd beneficiation process to obtain a 3 rd beneficiation froth and a 3 rd beneficiation middlings (denoted middlings 5). Middling 5 is used as a raw material to be selected and returned to the 2 nd carefully selecting process and the 1 st carefully selecting foam material of a new round are ground and scrubbed for 5min in a vertical mill.

The 3 rd beneficiation froth was subjected to a 4 th beneficiation process to obtain concentrate and a 4 th beneficiation middling (designated middling 6). The middling 6 is used as a raw material to be selected and returned to the 3 rd concentration process.

And (3) carrying out 1 st scavenging on the roughing liquid material obtained by roughing to obtain 1 st scavenging foam middling (marked as middling 2) and 1 st scavenging residual slurry. The middling 2 is used as a raw material to be selected and returned to the roughing process.

The remaining slurry from the 1 st scavenging process was subjected to the 2 nd scavenging process to obtain tailings and the 2 nd scavenging foam middlings (noted middling 1). Middling 1 is used as a raw material to be selected and returned to the 1 st scavenging process.

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

The beneficiating agents used for each beneficiation include graphite collectors (kerosene) and frothers (MIBC, optional). Wherein, the dosage of kerosene used in the 1 st selection is 53g/t, and the dosage of MIBC is 58g/t; the amount of kerosene used for the 2 nd carefully selecting is 53g/t, and the amount of MIBC is 58g/t; the amount of kerosene used for the 3 rd selection is 53g/t, and the amount of MIBC is 29g/t; the amount of kerosene used for the 4 th beneficiation was 26.5g/t and the amount of MIBC was 0g/t.

The scavenger used for each scavenger includes a graphite collector (kerosene) and a foaming agent (MIBC). Wherein, the dosage of kerosene used in the 1 st scavenging is 106g/t, and the dosage of MIBC is 58g/t; the amount of kerosene used in the 2 nd sweep was 53g/t and the amount of MIBC was 58g/t.

S7: and (3) carrying out acid leaching, impurity removal and extraction on the tailings and a reducing agent together, and extracting nickel, cobalt and manganese and the rest lithium to obtain a qualified nickel, cobalt, manganese and lithium product.

Example 2

The difference between this example and example 1 is that in S2, the baking temperature is 450 ℃.

Example 3

This example differs from example 1 in that in S3 the water immersion temperature is 25 ℃.

Example 4

The difference between this example and example 1 is that in S3, the stirring speed of the water immersion was 500rpm.

Example 5

The difference between this example and example 1 is that in S6, a stabilizer (aluminum sulfate) was not added during the roughing.

Example 6

The difference between this example and example 1 is that in S6, the amount of kerosene and MIBC used in the roughing process is reduced, specifically, the amount of kerosene is 106g/t and the amount of MIBC is 116g/t.

Example 7

This example differs from example 1 in that no pH adjuster (calcium oxide) was added during the roughing in S6.

Example 8

The difference between this example and example 1 is that step S5 is not performed, i.e. no ultrasonic dispersion is performed before flotation, and the water leaching residue is directly subjected to flotation.

Example 9

This example differs from example 1 in that in S6, no stabilizer (aluminum sulfate) or pH adjuster (calcium oxide) was added during the roughing.

Example 10

The difference between this example and example 1 is that in S6, the flotation agent used in the roughing process comprises a pH regulator (calcium carbonate and calcium hydroxide in a mass ratio of 1:1, 200 g/t), a stabilizer (ferric chloride, 200 g/t), a flocculant (sodium carboxymethyl cellulose, 500 g/t), a graphite collector (diesel oil, 50 g/t), and a foaming agent (pinitol oil, 50 g/t).

The amount of diesel oil used for each selection is 10g/t, and the amount of pine oil used for each selection is 10g/t.

The consumption of diesel oil used in each scavenging is 10g/t, and the consumption of pine oil used in each scavenging is 10g/t.

Example 11

The difference between this example and example 1 is that in S6, the flotation agent used in the roughing process comprises a pH regulator (sodium carbonate and sodium hydroxide in a mass ratio of 1:1, 4000 g/t), a stabilizer (magnesium nitrate, 2000 g/t), a flocculant (dextrin, 2000 g/t), a graphite collector (kerosene, 500 g/t), and a frother (sec-octanol, 400 g/t).

The amount of kerosene used per beneficiation was 150g/t and the amount of sec-octanol used per beneficiation was 150g/t.

The amount of kerosene used for each sweep was 150g/t, and the amount of octanol used for each sweep was 150g/t.

Example 12

The difference between this example and example 1 is that the number of selections in S6 is 2.

Example 13

The difference between this example and example 1 is that the number of selections in S6 is 3.

Example 14

The difference between this embodiment and embodiment 1 is that in S6, the number of times of the scavenging is 1.

Example 15

The difference between this example and example 1 is that in S2, the baking temperature is 800 ℃.

Comparative example 1

This comparative example differs from example 1 in that no flocculant (starch) was added during the roughing in S6.

Comparative example 2

This comparative example differs from example 1 in that in S6, no flocculant (starch) or pH adjuster (calcium oxide) was added during the roughing.

Comparative example 3

This comparative example differs from example 1 in that in S6, no flocculant (starch) or stabilizer (aluminum sulfate) was added during the roughing.

Comparative example 4

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

Comparative example 5

The comparative example differs from example 1 in that the amount of kerosene used in the roughing process was 600g/t.

Comparative example 6

The difference between this comparative example and example 1 is that the MIBC was used in an amount of 20g/t during the roughing process.

Comparative example 7

The difference between this comparative example and example 1 is that the MIBC was used in an amount of 450g/t during the roughing process.

Comparative example 8

The difference between this comparative example and example 1 is that the amount of corn starch used in the roughing process was 400g/t.

Comparative example 9

The difference between this comparative example and example 1 is that the amount of corn starch used in the roughing process was 2400g/t.

Comparative example 10

The comparative example differs from example 1 in that the amount of calcium oxide used in the roughing process was 150g/t.

Comparative example 11

The comparative example differs from example 1 in that the amount of calcium oxide used during the roughing process was 4200g/t.

Comparative example 12

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

Comparative example 13

The difference between this comparative example and example 1 is that the amount of kerosene used per beneficiation is 0g/t.

Comparative example 14

The difference between this comparative example and example 1 is that the amount of kerosene used for each beneficiation is 200g/t.

Comparative example 15

The difference between this comparative example and example 1 is that the amount of MIBC used per beneficiation is 0g/t.

Comparative example 16

The difference between this comparative example and example 1 is that the amount of MIBC used per beneficiation is 200g/t.

Comparative example 17

The comparative example differs from example 1 in that the amount of kerosene used per sweep was 0g/t.

Comparative example 18

The comparative example differs from example 1 in that the amount of kerosene used per sweep was 200g/t.

Comparative example 19

The difference between this comparative example and example 1 is that the amount of MIBC used per sweep is 0g/t.

Comparative example 20

The difference between this comparative example and example 1 is that the amount of MIBC used per sweep is 200g/t.

Comparative example 21

The comparative example differs from example 1 in that in S2, the firing temperature was 300 ℃.

Comparative example 22

The comparative example differs from example 1 in that in S2, the firing temperature was 1000 ℃.

Test examples

The following tests were carried out on the above examples and comparative examples:

(1) the raw material (battery black powder) and the contents of Li in the leachate and the leaching residue obtained in each leaching process were tested to obtain the corresponding leaching rates, and the results are shown in table 1.

(2) The content of fixed carbon in tailings and concentrates obtained in the ore feeding (battery black powder) and flotation process was tested to obtain corresponding recovery rates, and the results are shown in table 2.

Table 1 results of water immersion test

Table 2 flotation test results

As can be seen from table 1, the method provided by the present disclosure can effectively extract Li, and the Li leaching rate is higher. From table 2, it can be seen that the method provided by the present disclosure can effectively recover graphite, the graphite recovery rate is high, and the fixed carbon content in the recovered graphite product is high.

In summary, the method for integrally recycling lithium and graphite in the waste batteries through the full chain is simple and easy, lithium and graphite in the waste batteries can be effectively recycled, the recovery rates of lithium and graphite are high, and resource waste is avoided.

The foregoing is merely a preferred embodiment of the present disclosure, and is not intended to limit the present disclosure, so that various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Industrial applicability

The method for integrally recycling the lithium and the graphite in the waste battery through the full chain is simple and easy, the lithium and the graphite in the waste battery can be effectively recycled, the recycling rates of the lithium and the graphite are both high, the fixed carbon content of the recycled graphite is high, and resource waste is avoided.

Claims

1. A full-chain integrated method for recycling lithium and graphite in used batteries, which is characterized by including the following steps:

The battery black powder obtained from used batteries is roasted and lithium is extracted with water, and the water leaching residue is flotated;

Among them, flotation includes: using a flotation agent to conduct a rough selection of the water leaching residue to obtain a rough selection foam material and a rough selection slurry; performing at least one selection of the rough selection foam material to finally obtain a carbonaceous material. concentrate;

The flotation agent includes graphite collector, regulator and foaming agent; the regulator includes flocculant.

2. The method according to claim 1, characterized in that the graphite collector includes at least one of kerosene and diesel;

And/or, the flocculant includes at least one of starch, sodium carboxymethylcellulose and dextrin;

And/or, the foaming agent includes at least one of methyl isobutyl carbinol, pine alcohol oil and sec-octanol.

3. The method according to claim 1 or 2, characterized in that the dosage of the graphite collector is 50g/t-500g/t; and/or the dosage of the flocculant is 500g/t-2000g /t; and/or, the dosage of the foaming agent is 50g/t-400g/t.

4. The method according to any one of claims 1 to 3, characterized in that the adjusting agent further includes at least one of a pH adjusting agent and a stabilizing agent.

5. The method according to claim 4, wherein the pH adjuster includes at least one of calcium oxide, calcium carbonate, calcium hydroxide, sodium carbonate and sodium hydroxide;

And/or, the stabilizer includes 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 at least one of them.

6. The method according to claim 4 or 5, characterized in that the dosage of the pH regulator is 200g/t-4000g/t, and/or the dosage of the stabilizer is 200g/t-2000g/ t.

7. The method according to any one of claims 1-6, characterized in that the number of selections is n times, n≥2 and is an integer; in the first n-1 selection processes, after each selection The n-1th selected foam material and the n-1th selected medium ore are respectively obtained; the n-1th selected foam material is used as the raw material to be selected for the n-th selection.

8. The method according to claim 7, characterized in that when n=2, the first-time concentrated ore obtained in the first-time concentration is returned to the roughing process as the raw material to be selected.

9. The method according to claim 7 or 8, characterized in that when n=2, the second concentration of medium ore obtained in the second concentration is returned to the first concentration process as the raw material to be selected. .

10. The method according to claim 7, characterized in that when n ≥ 3, the n-1th concentrated ore obtained from the n-1th concentration is returned to the n-2th mine as the raw material to be selected. sub-selection process.

11. The method according to claim 7 or 10, characterized in that the n-th fine ore obtained from the n-th fine selection is returned to the n-1 th fine selection process as the raw material to be selected.

12. The method according to claim 9 or 10, characterized in that when there is a finely selected medium ore as a raw material to be selected and returned to the second beneficiation process, the first beneficiation process is carried out before the second beneficiation. The second selected foam material is combined with the third selected medium ore for grinding and scrubbing.

13. The method according to claim 12, characterized in that the scrubbing time is 2min-15min.

14. The method according to any one of claims 1 to 13, characterized in that the concentrating agent used in each concentrating process independently includes graphite collector and foaming agent.

15. The method according to claim 14, characterized in that the graphite collector used in each beneficiation process includes at least one of kerosene and diesel;

And/or, the foaming agent used in each selection process includes at least one of methyl isobutyl carbinol, pine alcohol oil and sec-octanol.

16. The method according to claim 14 or 15, characterized in that the amount of graphite collector used in each selection process is 0-150g/t; and/or the foaming agent used in each selection process is The dosage of agent is 0-150g/t.

17. The method according to any one of claims 1 to 16, characterized in that flotation further includes: sweeping the roughing slurry at least once to finally obtain carbon-containing tailings.

18. The method according to claim 17, characterized in that the number of sweeps is m times, m≥2 and is an integer; during the first m-1 sweeps, the m-th sweep is obtained after each sweep. The remaining slurry from the 1st sweep and the m-1th sweep are used to select the foamed ore; the remaining slurry from the m-1th sweep is used as the raw material to be selected for the m-th sweep.

19. The method according to claim 18, characterized in that when m=2, the foamed medium ore obtained in the first sweep is returned to the roughing process as the raw material to be selected.

20. The method according to claim 18 or 19, characterized in that when m=2, the second sweeping foam medium ore obtained in the second sweeping is returned to the first sweeping as raw material to be selected. process.

21. The method according to claim 18, characterized in that when m ≥ 3, the m-1th sweeping foam medium ore obtained from the m-1th sweeping is returned to the m-th as the raw material to be selected. 2 scanning processes.

22. The method according to claim 18 or 21, characterized in that the m-th sweeping foam medium ore obtained by the m-th sweeping is returned to the m-1th sweeping process as a raw material to be selected.

23. The method according to any one of claims 17 to 22, characterized in that the sweeping agent used for each sweep independently includes a graphite collector and a foaming agent.

24. The method according to claim 23, characterized in that the graphite collector used in each sweeping process includes at least one of kerosene and diesel;

And/or, the foaming agent used in each sweeping process includes at least one of methyl isobutyl carbinol, pine alcohol oil and sec-octanol.

25. The method according to claim 23 or 24, characterized in that the amount of graphite collector used in each sweeping process is 0-150g/t; and/or the foaming agent used in each sweeping process The dosage of agent is 0-150g/t.

26. The method according to any one of claims 17 to 25, characterized in that the number of rough selections is one, the number of selections is four, and the number of sweeps is two.

27. The method according to any one of claims 1 to 26, wherein the main source of battery black powder includes lithium-containing positive electrode materials and graphite-containing negative electrode materials.

28. The method of claim 27, wherein the source of battery black powder further includes at least one of a current collector and battery impurities.

29. The method of claim 28, wherein the current collector includes copper foil or aluminum foil.

30. The method according to any one of claims 1-29, characterized in that, in terms of mass percentage, the fixed carbon content in the battery black powder is 30%-55% and the Li content is 3%-7%. , Ni content is 10%-35%, Co content is 2%-5%, Mn content is 2%-5%, Cu content is 0.055-1%, Al content is 0.05%-1% and Fe content is 0.05% -1%.

31. The method according to any one of claims 1 to 30, characterized in that the preparation of battery black powder includes: discharging, crushing, cracking and screening used batteries.

32. The method of any one of claims 1-31, wherein roasting includes at least one of the following features:

Feature 1: Roasting temperature is 400℃-800℃;

Feature 2: Roasting time is 30min-180min;

Feature 3: Roasting is carried out in an oxygen-free environment.

33. The method of claim 32, wherein the oxygen-free environment is provided by nitrogen or an inert gas.

34. The method according to any one of claims 1 to 33, characterized in that water leaching lithium includes a water leaching process, and water leaching includes at least one of the following characteristics:

Feature 1: The solid-liquid ratio of water immersion is 1:3-1:10;

Feature 2: The temperature of water immersion is 25℃-90℃;

Feature 3: The water immersion time is 30min-120min;

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

35. The method according to claim 34, characterized in that the stirring speed during the water immersion process is 500rpm-2000rpm.

36. The method according to claim 34 or 35, characterized in that water leaching lithium further includes a lithium extraction process, and the lithium extraction method includes evaporating the water leaching liquid obtained by the water leaching process.

37. The method according to claim 36, characterized in that evaporation is carried out by water bath evaporation.

38. The method according to claim 37, characterized in that the temperature of water bath evaporation is 80°C-100°C.

39. The method according to any one of claims 1 to 38, characterized in that, before flotation, it further includes dispersing the water leaching residue.

40. The method of claim 39, wherein the dispersion form is ultrasonic dispersion.

41. The method of claim 40, wherein the ultrasonic dispersion includes at least one of the following characteristics:

Feature 1: Ultrasonic dispersion is carried out after mixing the water leaching residue and water at a liquid-to-solid ratio of 1:3-1:10;

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

Feature 3: Ultrasonic dispersion time is 5min-20min.

42. The method according to any one of claims 1 to 41, characterized in that, after flotation, it also includes post-processing the flotation tailings product;

Post-processing includes acid leaching, impurity removal and extraction.