CN113444885A

CN113444885A - Method for preferentially extracting metal lithium from waste ternary lithium ion battery and simultaneously obtaining battery-grade metal salt

Info

Publication number: CN113444885A
Application number: CN202110631918.6A
Authority: CN
Inventors: 郑华均; 潘曜灵; 郑灵霞; 赵浙菲; 甄爱钢; 孔繁振; 凌怊
Original assignee: Zhejiang Tianneng New Material Co ltd; Zhejiang University of Technology ZJUT
Current assignee: Zhejiang Tianneng New Material Co ltd; Zhejiang University of Technology ZJUT
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2021-09-28
Anticipated expiration: 2041-06-07
Also published as: CN113444885B

Abstract

本发明提供了一种从废旧三元锂离子电池中优先提取金属锂以及同时得到电池级金属盐的方法，通过在清洁单一的氢气氛围下焙烧还原废旧电池黑粉，然后采用纯水浸出，达到优先提取金属锂资源的目标，且有效地提高了金属锂的回收率，回收过程中避免产生二氧化碳、二氧化硫等有害有毒废烟气，回收过程清洁环保；并且，采用镍皂有机萃取‑硫酸反萃的逆流萃取法，在萃取过程中避免其他金属杂质进入到溶液中，极大提高了金属盐的纯度，得到电池级硫酸钴、硫酸镍和硫酸锰，方法简单，回收成本低。The invention provides a method for preferentially extracting metal lithium from waste and used ternary lithium ion batteries and obtaining battery-grade metal salts at the same time. The goal of preferentially extracting metal lithium resources, and effectively improve the recovery rate of metal lithium, avoid the production of carbon dioxide, sulfur dioxide and other harmful and toxic waste gas during the recovery process, and the recovery process is clean and environmentally friendly; and, using nickel soap organic extraction-sulfuric acid stripping The countercurrent extraction method of the invention avoids other metal impurities from entering the solution during the extraction process, greatly improves the purity of the metal salt, and obtains battery-grade cobalt sulfate, nickel sulfate and manganese sulfate. The method is simple and the recovery cost is low.

Description

Method for preferentially extracting metal lithium from waste ternary lithium ion battery and simultaneously obtaining battery-grade metal salt

Technical Field

The invention belongs to the field of solid waste recovery and treatment, and particularly relates to a method for recovering high-purity metal resources from waste ternary lithium ion batteries in an environment-friendly, efficient and low-cost manner.

Background

Since the 90 s of the last century, with the innovation of positive electrode materials, negative electrode materials and electrolytes, lithium ion batteries have been commercialized and rapidly widely used in many fields. Particularly, the popularization of new energy automobiles leads the demand of lithium ion batteries to be rapidly increased, and the annual average growth rate reaches 9.4 percent. The metal resources for manufacturing the lithium ion battery, in particular to the scarce metal supply and demand gaps of mineral resources such as lithium, cobalt and the like are enlarged. Therefore, how to recover metal resources from waste lithium ion batteries and reuse the metal resources for manufacturing the lithium ion batteries is an important way for promoting the sustainable development of the lithium ion battery industry.

At present, the recovery of waste lithium ion batteries generally comprises the steps of firstly extracting metal resources such as nickel, cobalt, manganese and the like from black powder containing the metal resources by adopting a wet leaching and extraction technology, then finally extracting lithium metal resources in a carbonate precipitation mode, and leading the metal lithium resources to pass through the long process flow, so that the loss of the metal lithium resources in the recovery process is inevitably caused, and the recovery rate of lithium is obviously reduced; on the other hand, because a large amount of lithium ions exist in the processes of leaching, extraction and back extraction, the purity of nickel and cobalt salts obtained by extraction cannot reach the battery grade standard, and the nickel and cobalt salts are difficult to return to the remanufacturing of the lithium ion battery. Therefore, it is necessary to develop a method for preferentially extracting lithium and simultaneously recovering a battery-grade metal salt.

Chinese patent CN106129511A discloses a method for comprehensively recovering valuable metals from waste lithium ion battery materials, which mainly comprises the steps of mixing a waste lithium ion battery anode material with a reducing agent, carrying out reduction roasting treatment at the temperature of 500-750 ℃, and firstly adopting CO as a roasting product₂Immersing in carbonized water to obtain aqueous solution of lithium bicarbonate for preparing Li₂CO₃And (5) producing the product. Although the method realizes the preferential extraction of lithium metal, the Li is obtained because the anode material of the waste lithium ion battery inevitably contains impurities of other elements such as aluminum and the like₂CO₃The product is crude lithium carbonate, and a solid reducing agent is introduced, so that the leaching residue amount is increased.

The chinese patent application No. cn202010724526.x discloses a method for preparing lithium carbonate by using waste lithium ion batteries and battery-grade lithium carbonate, which comprises the steps of reducing and roasting powder of the waste lithium ion batteries by using natural gas, adding water for leaching and filtering, and then sequentially precipitating by using sulfuric acid and sodium carbonate to obtain lithium carbonate. Although the aim of preferentially extracting lithium is fulfilled, the lithium is roasted in the natural gas atmosphere, a large amount of carbon dioxide is generated in the roasting process, the incompletely-reacted natural gas can be directly discharged to the air after being treated, the graphite carbon in the black powder of the waste battery is not fully utilized, and the environment is not protected; in addition, there is no clear scheme for the subsequent purification of manganese, nickel and cobalt.

Chinese patent application CN 109935922A discloses a method for recovering valuable metals from waste lithium ion battery materials, which comprises the steps of mixing a waste lithium ion battery positive electrode material with low-valent sulfates such as sulfur and sulfide, carrying out vulcanization roasting treatment at the temperature of 300-900 ℃, leaching roasted products by water to obtain a lithium salt aqueous solution, further preparing a lithium carbonate product, leaching water leaching slag by adopting oxidation acid leaching or direct acid leaching to leach valuable elements such as nickel, cobalt, manganese and the like, and purifying and extracting leachate to obtain corresponding cobalt salt, nickel salt and the like. The method has the problems that sulfide is adopted for roasting, and the roasted flue gas contains a large amount of toxic and harmful gases such as sulfur dioxide or sulfur trioxide and needs further purification treatment; meanwhile, the recovery rate of the lithium salt is low, and the purity of other metals such as nickel-cobalt-manganese salt solution cannot reach the battery grade standard, so that the lithium salt is difficult to be directly used for remanufacturing the ternary lithium ion battery anode material.

Disclosure of Invention

The invention aims to provide a clean, low-carbon emission and high-recovery-rate recovery method for preferentially extracting metal lithium resources from waste ternary lithium ion batteries, and the recovered manganese sulfate, cobalt sulfate and nickel sulfate metal salts reach the battery-level standard established by technical innovation strategy alliance of the recovery environmental protection industry, and can be directly recycled for remanufacturing the lithium ion batteries.

The innovation of the invention is mainly as follows:

firstly, the metal lithium resource can be preferentially extracted at low cost by adopting low-temperature roasting in a hydrogen atmosphere, the recovery rate of the lithium resource is improved, and the influence of the recovery process on the environment is reduced;

second is R₂the-Ni structure is a soap-converting organic extractant, and a countercurrent extraction method is adopted to clarify the order of extracting metal resources, so that high-purity manganese sulfate and battery-grade cobalt sulfate and nickel sulfate are obtained.

The technical scheme of the invention is as follows:

a method for preferentially extracting metallic lithium from a waste ternary lithium ion battery and simultaneously obtaining battery-grade metal salt, comprising the following steps:

step 1: calcination with hydrogen

The method comprises the steps of carrying out overdischarge, disassembly and crushing, screening, carbonizing furnace roasting and multistage sorting on a waste ternary lithium ion battery to obtain black powder containing lithium, manganese, nickel and cobalt metal resources and graphite carbon, and carrying out reduction roasting on the black powder at the temperature of 500-700 ℃ for 2-4 hours under the hydrogen atmosphere of 0.02-0.2 MPa to obtain reduced powder;

step 2: preferential extraction of lithium

Adding the reduced powder obtained in the step 1 into pure water, uniformly dispersing, performing filter pressing to obtain filter residue and filtrate, and performing reduced pressure concentration and crystallization on the filtrate to obtain lithium hydroxide monohydrate;

the mass ratio of the reduction powder to the pure water is 1: 3-5;

the treatment effect of the steps 1-2 is as follows: the black powder is roasted, so that the metal lithium resource exists in the form of lithium oxide, and the lithium hydroxide is obtained by adding pure water to dissolve the metal lithium resource, and the recovery rate of the lithium resource reaches over 96 percent; meanwhile, reducing the metal manganese, cobalt and nickel into divalent metal ions for subsequent recovery;

and step 3: sulfuric acid leaching

Dissolving the filter residue obtained in the step 2 by using sulfuric acid to obtain a leaching solution, and controlling the pH value of the leaching solution to be 1.5-2;

the concentration of the sulfuric acid is 98 wt%, and the mass ratio of the filter residue to the sulfuric acid is 1: 5-6;

and 4, step 4: p204 extraction of impurities

Mixing the leachate obtained in the step 3 with a soap-conversion organic extractant P204, and controlling the volume ratio of an organic phase to a water phase to be 2-4: 1 (preferably 3: 1), extracting by using a counter-current extraction method (extracting impurity metal calcium, copper, zinc and aluminum ions and a small amount of metal manganese ions in the leachate into an organic phase), and collecting raffinate;

260# solvent oil is added into the soap-conversion organic extractant P204, and the volume of the P204 accounts for 20-30%;

the extraction stage number is 8-10 stages during extraction, and the pH of the water phase at the outlet of the extraction section is controlled to be 2.5-2.8;

washing the extracted organic phase by 0.5mol/L sulfuric acid, and washing for 12-13 levels; then, carrying out back extraction on the loaded organic P204 by using 2.0mol/L sulfuric acid, wherein the number of the back extraction stages is 6, so as to obtain a mixed solution of aluminum sulfate, calcium sulfate, copper sulfate, zinc sulfate and manganese sulfate; the no-load organic is recycled after being subjected to 3-level reverse iron and 2-level water washing;

the processing effect of the step 4 is as follows: in the extraction process, the impurities of calcium, aluminum, copper and zinc ions in the water phase are all extracted into the organic phase, so that the metal impurities are removed, and the subsequent processes are ensured to obtain battery-grade manganese sulfate, cobalt sulfate and nickel sulfate;

and 5: extraction of high purity manganese salt

Mixing the raffinate obtained in the step 4 with a soap-conversion organic extractant P204, and controlling the volume ratio of an organic phase to a water phase to be 2-4: 1 (preferably 3: 1), extracting by adopting a counter-current extraction method (completely extracting metal manganese ions in the raffinate in the step 4 into an organic phase), and collecting the raffinate;

the extraction stage number is 9-10 stages during extraction, and the pH of the water phase at the outlet of the extraction section is controlled to be 2.5-3.3;

washing the extracted organic phase by 0.5mol/L sulfuric acid, and washing for 12-13 levels; carrying out back extraction on the loaded organic P204 by using 2.2-2.3 mol/L sulfuric acid, wherein the number of the back extraction stages is 6, so as to obtain a high-purity manganese sulfate solution, and standing, deoiling, fine filtering, evaporating and crystallizing the high-purity manganese sulfate solution to obtain battery-grade manganese sulfate; the no-load organic is recycled after being subjected to 3-level reverse iron and 2-level water washing;

the processing effect of the step 5 is as follows: through the back extraction process, manganese ions completely enter the water phase, so that a high-purity manganese sulfate solution is obtained, and after the evaporation crystallization process, the product purity can reach more than 99%;

step 6: cobalt salt for extracting battery grade standard

Mixing the raffinate obtained in the step 5 with a soap-conversion organic extractant P507, and controlling the volume ratio of an organic phase to a water phase to be 2-4: 1 (preferably 3: 1), extracting by adopting a counter-current extraction method (extracting metal cobalt ions in the raffinate in the step 5 into an organic phase), and collecting the raffinate;

260# solvent oil is added into the soap-conversion organic extractant P507, and the volume of the P507 accounts for 20-30%;

the extraction stage number is 10-11 stages during extraction, and the pH of an outlet water phase of the extraction section is controlled to be 4.0-4.5;

washing the extracted organic phase by 0.5mol/L sulfuric acid, and washing for 14-15 grades; then, carrying out back extraction on the loaded organic P507 by using 2.4mol/L sulfuric acid, wherein the number of the back extraction stage is 6, so as to obtain a high-purity cobalt sulfate solution, and standing, deoiling, fine filtering, evaporating and crystallizing the high-purity cobalt sulfate solution to obtain battery-grade cobalt sulfate; the no-load organic is recycled after being subjected to 3-level reverse iron and 2-level water washing;

the processing effect of the step 6 is as follows: in the extraction process, cobalt ions in the water phase are all extracted into an organic phase; in the back extraction process, cobalt ions are completely dissolved back into a water phase, so that a high-purity cobalt sulfate solution is obtained; the battery-grade cobalt sulfate is obtained after the high-purity cobalt sulfate solution is subjected to subsequent treatment, and the mass fraction of metal cobalt in the product can reach more than 20.5%;

and 7: extraction of battery grade standard nickel salts

And (3) mixing the raffinate obtained in the step (6) with a soap-converting organic extractant Cyanex272, and controlling the volume ratio of an organic phase to a water phase to be 2-4: 1 (preferably 3: 1), extracting by adopting a countercurrent extraction method (extracting all impurity metal magnesium ions in the raffinate in the step 6 into an organic phase), collecting the raffinate, standing the raffinate, removing oil, finely filtering, evaporating and crystallizing to obtain battery-grade nickel sulfate;

260# solvent oil is added into a soap-converting organic extractant Cyanex272, and the volume of the Cyanex272 accounts for 20-30%;

the extraction stage number is 8-9 stages during extraction, and the pH of the water phase at the outlet of the extraction section is controlled to be 5.0-5.5;

washing the extracted organic phase by 0.5mol/L sulfuric acid, and washing for 6 grades; then carrying out back extraction on the loaded organic Cyanex272 by using 2mol/L sulfuric acid, wherein the number of the back extraction stages is 6; the no-load organic is recycled after being subjected to 3-level reverse iron and 2-level water washing;

the processing effect of the step 7 is as follows: in the extraction process, magnesium ions in the water phase are all extracted to an organic phase to obtain a high-purity nickel sulfate solution, the high-purity nickel sulfate solution is subjected to subsequent treatment to obtain battery-grade nickel sulfate, and the mass fraction of metal nickel in the product can reach more than 22.1%.

Step 4, step 5 and step of the invention6 and 7, the structure of the soap-converting organic extractant used is R₂Ni, the method adopted is to saponify the organic extractant with liquid alkali and then to convert the nickel sulfate into soap. The saponification grade number of P204 is 2 grades, and the soap conversion grade number of nickel sulfate is 6 grades; the saponification grade of P507 is 2 grades, and the soap conversion grade of nickel sulfate is 6 grades; CY-272 saponification grade is 3 grades, and nickel sulfate is converted into soap grade 6. Extraction with a soap-converting organic extractant avoids mixing metallic Na ions into the aqueous phase.

The method for preferentially extracting the metal lithium from the black powder of the waste ternary lithium ion battery and simultaneously obtaining the high-purity metal manganese, cobalt and nickel salts has the beneficial effects that:

firstly, the black powder of the waste battery is roasted and reduced in a clean and single hydrogen atmosphere, and then pure water is adopted for leaching, so that the aim of preferentially extracting the metal lithium resource is achieved, the recovery rate of the metal lithium is effectively improved, harmful and toxic waste flue gas such as carbon dioxide, sulfur dioxide and the like is avoided in the recovery process, and the recovery process is clean and environment-friendly;

and secondly, a countercurrent extraction method of nickel soap organic extraction-sulfuric acid back extraction is adopted, other metal impurities are prevented from entering a solution in the extraction process, the purity of metal salt is greatly improved, and the battery-grade sulfate is obtained through subsequent processes of standing, oil removal, fine filtration and the like, so that the method is simple and the recovery cost is low.

Drawings

FIG. 1: the invention relates to a process flow chart.

Detailed Description

The invention is further described below by means of specific examples, without the scope of protection of the invention being limited thereto.

Example 1

Step 1: the black powder of the waste battery is obtained after the waste ternary lithium ion battery is subjected to overdischarge, disassembly and crushing, screening, carbonization furnace roasting and multistage separation. The contents of metal nickel, cobalt, manganese and lithium in the black powder of the waste battery are respectively 32.73, 7.50, 16.99 and 6.54 percent, and impurities such as aluminum, calcium, magnesium, copper and the like also exist in the black powder.

And (3) roasting the black powder for 2.8 hours at 550 ℃ in a hydrogen atmosphere, and controlling the pressure of hydrogen in the rotary kiln to be 0.02MPa to obtain the reduced powder.

Step 2: and (3) adding the reduced powder obtained in the step (1) into pure water, fully stirring, and carrying out filter pressing to obtain filter residue and a lithium hydroxide solution, wherein 92% of metal lithium is leached into the solution.

And step 3: and (3) dissolving the filter residue obtained in the step (2) by using sulfuric acid with the concentration of 98 percent to obtain a leaching solution with the pH value of 1.5.

And 4, step 4: and (3) fully mixing the leachate obtained in the step (3) with a nickel soap organic extractant P204, mixing the organic extractant P204 with No. 260 solvent oil in a ratio of 25%, controlling the extraction stage number to be 9 stages, controlling the volume ratio of an organic phase to a water phase to be 3:1, controlling the pH value of the water phase at the outlet of the extraction stage to be 2.8, and performing countercurrent extraction on the organic phase and the water phase. Washing the organic phase obtained after extraction with 0.5mol/L sulfuric acid, wherein the washing stage number is 13 stages, and then back-extracting the loaded organic P204 with 2.0mol/L sulfuric acid to obtain a mixed solution of manganese sulfate, calcium sulfate, copper sulfate, zinc sulfate and aluminum sulfate, wherein the back-extraction stage number is 6 stages. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing.

And 5: and (3) fully mixing the raffinate obtained in the step (4) with a nickel soap organic extractant P204, mixing the organic extractant P204 with No. 260 solvent oil in a ratio of 25%, controlling the extraction stage number to be 9 stages, controlling the volume ratio of an organic phase to an aqueous phase to be 3:1, controlling the pH value of the aqueous phase at the outlet of the extraction stage to be 2.8, and performing countercurrent extraction on the organic phase and the aqueous phase. Washing the organic phase obtained after extraction with 0.5mol/L sulfuric acid, wherein the washing stage number is 13 stages, and then back-extracting the loaded organic P204 with 2.2mol/L sulfuric acid to obtain a manganese sulfate solution, wherein the back-extraction stage number is 6 stages. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing. Standing the manganese sulfate solution, removing oil, finely filtering, and evaporating and crystallizing to obtain the battery-grade manganese sulfate. The manganese content in the obtained manganese sulfate is 32.3 percent, and the contents of impurities such as cobalt, nickel, magnesium and calcium are respectively 0.0032 percent, 0.0041 percent, 0.0054 percent and 0.0088 percent, which reach the standard of HG/T4823-.

Step 6: mixing the raffinate in the step 5 with a nickel soap organic extractant P507, mixing the organic extractant with No. 260 solvent oil according to 25 percent of the P507, controlling the extraction stage number to be 11 stages, controlling the volume ratio of an organic phase to a water phase to be 3:1, controlling the pH value of the water phase at the outlet of the extraction stage to be 4.0, and carrying out countercurrent extraction on the organic phase and the water phase. Washing the extracted organic phase with 0.5mol/L sulfuric acid, wherein the washing grade is 15 grades, and then back-extracting the loaded organic P507 with 2.4mol/L sulfuric acid to obtain a cobalt sulfate solution, wherein the back-extraction grade is 7 grades. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing. The battery-grade cobalt sulfate solution is obtained after standing, oil removal and fine filtration of the cobalt sulfate solution, wherein the cobalt content in the chemical components is 115.72g/L, and the contents of impurities such as manganese, nickel, magnesium and calcium are respectively 0.0058, 0.0145, 0.0023 and 0.0022g/L, and reach the standard of T/ATCRR 10-2020.

And 7: and (3) mixing the raffinate obtained in the step (6) with a soap-converting organic extractant Cyanex272, mixing the organic extractant with No. 260 solvent oil in an amount of 25 percent of CY-272, controlling the extraction stage number to be 9 stages, controlling the volume ratio of an organic phase to an aqueous phase to be 3:1, controlling the pH value of the aqueous phase at the outlet of the extraction stage to be 5.2, and performing countercurrent extraction on the organic phase and the aqueous phase. And standing, deoiling and fine filtering the raffinate, and evaporating to obtain the battery-grade nickel sulfate solution. The nickel content in the obtained nickel sulfate is 120.98g/L, the contents of impurities of manganese, cobalt, magnesium and calcium are respectively 0.86 ppm, 17.65 ppm, 2.31 ppm and 1.10ppm, and the standard of T/ATCRR 12-2020 is reached.

Loading an organic extractant, washing 7 grades, performing 2mol/L sulfuric acid back extraction to obtain a magnesium sulfate solution, wherein the number of back extraction stages is 6 grades, and performing 3-grade iron back washing and 2-grade water washing on the magnesium sulfate solution to recycle the organic extractant.

Example 2

And (3) roasting the black powder for 3 hours at 570 ℃ under the hydrogen atmosphere, and controlling the pressure of hydrogen in the rotary kiln to be 0.03MPa to obtain the reduced powder.

Step 2: and (3) adding the reduced powder obtained in the step (1) into pure water, fully stirring, and carrying out filter pressing to obtain filter residue and a lithium hydroxide solution, wherein 94% of metal lithium is leached into the solution.

And step 3: and (3) dissolving the filter residue obtained in the step (2) by using sulfuric acid with the concentration of 98 percent to obtain a leaching solution with the pH value of 1.7.

And 4, step 4: and (3) fully mixing the leachate obtained in the step (3) with a nickel soap organic extractant P204, mixing the organic extractant P204 with No. 260 solvent oil in a ratio of 25%, controlling the extraction stage number to be 10 stages, controlling the volume ratio of an organic phase to a water phase to be 3:1, controlling the pH value of the water phase at the outlet of the extraction stage to be 2.7, and performing countercurrent extraction on the organic phase and the water phase. Washing the organic phase obtained after extraction with 0.5mol/L sulfuric acid, wherein the washing stage number is 13 stages, and then back-extracting the loaded organic P204 with 2.0mol/L sulfuric acid to obtain a mixed solution of manganese sulfate, calcium sulfate, copper sulfate, zinc sulfate and aluminum sulfate, wherein the back-extraction stage number is 6 stages. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing.

And 5: and (3) fully mixing the raffinate obtained in the step (4) with a nickel soap organic extractant P204, mixing the organic extractant P204 with No. 260 solvent oil in a ratio of 25%, controlling the extraction stage number to be 9 stages, controlling the volume ratio of an organic phase to an aqueous phase to be 3:1, controlling the pH value of the aqueous phase at the outlet of the extraction stage to be 2.9, and performing countercurrent extraction on the organic phase and the aqueous phase. Washing the organic phase obtained after extraction with 0.5mol/L sulfuric acid, wherein the washing stage number is 12, and then back-extracting the loaded organic P204 with 2.2mol/L sulfuric acid to obtain a manganese sulfate solution, wherein the back-extraction stage number is 6. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing. Standing the manganese sulfate solution, removing oil, finely filtering, and evaporating and crystallizing to obtain the battery-grade manganese sulfate. The manganese in the obtained manganese sulfate is 32.8 percent, and the contents of impurities such as cobalt, nickel, magnesium and calcium are respectively 0.0042 percent, 0.0039 percent, 0.0074 percent and 0.0079 percent, which reach the standard of HG/T4823-.

Step 6: mixing the raffinate in the step 5 with a nickel soap organic extractant P507, mixing the organic extractant with No. 260 solvent oil according to 25 percent of the P507, controlling the extraction stage number to be 11 stages, controlling the volume ratio of an organic phase to a water phase to be 3:1, controlling the pH value of the water phase at the outlet of the extraction stage to be 4.2, and carrying out countercurrent extraction on the organic phase and the water phase. Washing the extracted organic phase with 0.5mol/L sulfuric acid, wherein the washing grade is 14 grades, and then back-extracting the loaded organic P507 with 2.4mol/L sulfuric acid to obtain a cobalt sulfate solution, wherein the back-extraction grade is 6 grades. And the unloaded organic is recycled after being subjected to 3-level reverse iron and 2-level water washing. The battery-grade cobalt sulfate solution is obtained after standing, oil removal and fine filtration of the cobalt sulfate solution, wherein the cobalt content in the chemical components is 117.43g/L, the contents of impurities such as manganese, nickel, magnesium and calcium are respectively 0.0050, 0.0054, 0.0015 and 0.0015g/L, and the standard of T/ATCRR10-2020 is reached.

And 7: and (3) mixing the raffinate obtained in the step (6) with a soap-converting organic extractant Cyanex272, mixing the organic extractant with No. 260 solvent oil in an amount of 25 percent of CY-272, controlling the extraction stage number to be 10 stages, controlling the volume ratio of an organic phase to an aqueous phase to be 3:1, controlling the pH value of the aqueous phase at the outlet of the extraction stage to be 5.1, and performing countercurrent extraction on the organic phase and the aqueous phase. And standing, deoiling and fine filtering the raffinate, and evaporating to obtain the battery-grade nickel sulfate solution. The nickel content in the obtained nickel sulfate is 119.39g/L, the contents of impurities of manganese, cobalt, magnesium and calcium are respectively 1.35 ppm, 12.69 ppm, 0.27 ppm and 0.64ppm, and the standard of T/ATCRR 12-2020 is reached.

Claims

1. a method for preferentially extracting metal lithium and obtaining battery-grade metal salt simultaneously from waste and old ternary lithium ion batteries, it is characterized in that, described method comprises the steps:

Step 1: Hydrogen Roasting

The waste ternary lithium-ion battery is discharged, disassembled and broken, screened, roasted in a carbonization furnace and multi-stage sorted to obtain a black powder containing lithium, manganese, nickel, cobalt metal resources and graphitic carbon. Under 0.2MPa hydrogen atmosphere, reduce and bake at 500～700℃ for 2～4h to obtain reduced powder;

Step 2: Priority lithium extraction

The reduced powder obtained in step 1 is added to pure water to disperse uniformly, and pressure-filtered to obtain filter residue and filtrate, and the filtrate is concentrated under reduced pressure and crystallized to obtain lithium hydroxide monohydrate;

Step 3: leaching and extracting impurities

Dissolve the filter residue obtained in step 2 with 98wt% sulfuric acid to obtain a leaching solution; mix the leaching solution with a soap-turning organic extractant P204, and use countercurrent extraction to extract impurity metal calcium, copper, zinc and aluminum ions into the organic phase to remove, and collect the raffinate ;

Step 4: Extract Manganese, Cobalt, Nickel

The metal resources in the raffinate of step 3 are extracted according to the order of manganese-cobalt-nickel by using a soap-turning organic extractant, and by countercurrent extraction, high-purity manganese sulfate, battery-grade cobalt sulfate and nickel sulfate are respectively obtained.

2. the method for preferentially extracting metallic lithium and simultaneously obtaining battery-grade metal salt from waste and old ternary lithium ion battery as claimed in claim 1, it is characterized in that, the method for extracting manganese, cobalt, nickel is:

Step a: Extraction of high-purity manganese salts

The raffinate collected after leaching and impurity extraction is mixed with the soap-turning organic extractant P204, the volume ratio of the organic phase and the water phase is controlled to be 2-4:1, and the countercurrent extraction method is used for extraction to collect the raffinate;

The extracted organic phase is first washed with 0.5mol/L sulfuric acid, and then back-extracted with 2.2-2.3mol/L sulfuric acid to obtain a manganese sulfate solution. ;

Step b: Extraction of battery-grade standard cobalt salts

The raffinate of step a is mixed with the soap-turning organic extractant P507, the volume ratio of the organic phase and the water phase is controlled to be 2-4:1, the countercurrent extraction method is used for extraction, and the raffinate is collected;

The extracted organic phase is first washed with 0.5mol/L sulfuric acid, and then back-extracted with 2.4mol/L sulfuric acid to obtain a cobalt sulfate solution.

Step c: Extraction of battery-grade nickel salts

The raffinate of step b is mixed with the soap-turning organic extractant Cyanex272, the volume ratio of the organic phase and the water phase is controlled to be 2 to 4:1, the extraction is carried out by a countercurrent extraction method, the raffinate is collected, and the raffinate is allowed to stand and remove. After oil, fine filtration and evaporative crystallization, battery grade nickel sulfate is obtained.

3. the method for preferentially extracting metal lithium and obtaining battery-grade metal salt simultaneously from waste and old ternary lithium ion battery as claimed in claim 2, it is characterized in that, in step a, transfer soap organic extractant P204 to be added with 260# solvent Oil, P204 volume accounts for 20 to 30%.

4. the method for preferentially extracting metallic lithium from waste ternary lithium ion battery as claimed in claim 2 and obtaining battery-grade metal salt simultaneously, it is characterized in that, in step a: the extraction order number is 9～10 grades during extraction, control The pH of the aqueous phase at the outlet of the extraction section is 2.5-3.3; the organic phase after extraction is first washed with 0.5mol/L sulfuric acid, and washed for grades 12-13; The number is 6 grades to obtain manganese sulfate solution, which is left standing, degreasing, fine filtration and evaporative crystallization to obtain high-purity manganese sulfate; no-load organics are reused after 3 grades of anti-iron and 2 grades of water washing.

5. the method for preferentially extracting metallic lithium from waste ternary lithium ion battery as claimed in claim 2 and obtaining the method for battery-grade metal salt simultaneously, it is characterized in that, in step b, in the soap organic extractant P507, 260# solvent is added Oil, P507 accounts for 20 to 30% of the volume.

6. the method for preferentially extracting metallic lithium from waste ternary lithium ion batteries and simultaneously obtaining battery-grade metal salts as claimed in claim 2, is characterized in that, in step b: during extraction, the number of extraction stages is 10～11, and the control The pH of the water phase at the outlet of the extraction section is 4.0 to 4.5; the organic phase after extraction is first washed with 0.5 mol/L sulfuric acid for 14 to 15 grades; Grade 6, a cobalt sulfate solution is obtained, which is left standing, degreasing, fine filtration, and evaporated and crystallized to obtain battery-grade cobalt sulfate; no-load organics are reused after 3-stage anti-iron and 2-stage water washing.

7. the method for preferentially extracting metal lithium and obtaining battery-grade metal salt simultaneously from waste and old ternary lithium ion battery as claimed in claim 2, it is characterized in that, in step c, is added with 260# solvent in the soap organic extractant Cyanex272 Oil, Cyanex272 accounts for 20 to 30% by volume.

8. the method for preferentially extracting metallic lithium from waste ternary lithium ion battery as claimed in claim 2 and obtaining battery-grade metal salt simultaneously, it is characterized in that, in step c: the number of extraction stages is 8～9 grades during extraction, control The pH of the water phase at the outlet of the extraction section is 5.0-5.5; the organic phase after extraction is first washed with 0.5mol/L sulfuric acid, and washed for 6 stages; The no-load organic is reused after 3-level anti-iron and 2-level water washing.

9. the method for preferentially extracting metallic lithium from waste ternary lithium ion battery as claimed in claim 1 and obtaining battery grade metal salt simultaneously, it is characterized in that, in step 3, is added with 260# solvent in the soap organic extractant P204 Oil, P204 volume accounts for 20 to 30%.

10. The method for preferentially extracting metal lithium from waste ternary lithium-ion batteries and simultaneously obtaining battery-grade metal salts as claimed in claim 1, wherein in step 3: the number of extraction stages during extraction is 8 to 10, and the control The pH of the water phase at the outlet of the extraction section is 2.5 to 2.8; the organic phase after extraction is first washed with 0.5 mol/L sulfuric acid for 12 to 13 grades; Grade 6, a mixed solution of aluminum sulfate, calcium sulfate, copper sulfate, and zinc sulfate is obtained; no-load organics are reused after being washed with level 3 anti-iron and level 2 water.