Method for removing impurities and extracting manganese from lithium ion battery black powder

Abstract

The present application relates to a kind of lithium ion battery black powder collaborative impurity removal and the method for extracting manganese, belong to lithium battery recycling technical field.The method includes the following steps: acid leaching black powder;Displacement removes copper ion;Oxidation ferrous ion;Hydrolysis removes iron aluminum;Extraction extracts manganese ion;Stripping extracts manganese ion.The present application cooperatively utilizes permanganate ion to oxidize the ferrous ion of high pH hydrolysis into the iron ion of low pH hydrolysis, improves the removal rate of impurity iron metal ion under the condition of not introducing other metal ions.Extra introduced manganese ion will be enriched and recovered by extraction method.The present application finally obtains manganese metal inorganic compound and extraction raffinate rich in nickel, cobalt and lithium valuable metal, is conducive to subsequent further separation operation and simplifies purification step.

Description

Technical Field

[0001] This invention relates to a method for the synergistic removal of impurities from lithium-ion battery black powder and the extraction of manganese, belonging to the field of lithium battery recycling technology. Background Technology

[0002] In recent years, the number of new energy lithium-ion battery vehicles has exploded. The resulting large-scale retirement of lithium-ion batteries will have a significant impact on the ecological environment and human health. Developing efficient strategies for recycling valuable metals from lithium-ion batteries is an important way to address this problem.

[0003] The recycling of spent lithium-ion batteries mainly includes pretreatment, metal enrichment and purification, and product preparation. The pretreatment process includes discharging and disassembling the batteries, crushing and sieving the battery cells, etc. The black powder obtained after pretreatment is rich in active materials, and then valuable metals are recovered through pyrometallurgical or hydrometallurgical processes. Due to the complex internal structure of the batteries, the black powder obtained during the pretreatment process contains impurity metals such as copper, iron, and aluminum. The presence of these impurity metals reduces the purity of the recovered metals such as nickel, cobalt, manganese, and lithium.

[0004] Chinese patent application CN112079369A discloses a pyrometallurgical recovery process for preferential lithium extraction. This invention introduces chlorides such as calcium chloride, zinc chloride, barium chloride, sodium chloride, copper chloride, and potassium chloride to separate lithium from transition metals and impurities (Cu / Al) during roasting. However, this method imposes a purification step on the subsequent extraction of nickel, cobalt, and manganese metals.

[0005] Chinese patent application CN114678617A discloses a method for removing impurities from waste ternary lithium battery black powder using phosphate. This invention uses 1,3-diamino-2-propanol, phthalic anhydride, triethylamine, toluene, hydrazine hydrate, nickel chloride, ethanol, and sulfur dioxide as raw materials, and obtains a metal scavenger through a three-step reaction. However, the numerous raw materials and complex synthesis steps increase the cost of the recycling process. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a method for the synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder. The method introduces a highly oxidizing high-valence manganese salt to remove copper, iron, and aluminum impurities from the acid leaching solution of the black powder; simultaneously, the introduced manganese ions, together with the original manganese ions in the acid leaching solution, can be recovered and extracted again.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows.

[0008] A method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder, the method comprising the following steps: S1. Acid-leached black powder: Lithium-ion battery black powder is leached with acid to obtain an acid leaching solution rich in nickel, cobalt, manganese, lithium organometallic and copper, iron, and aluminum impurity metal ions. S2, copper ion removal by displacement: iron metal is added to the acid leaching solution described in step S1 to carry out a displacement reaction, resulting in an acid leaching solution and sponge copper solid after copper removal; S3, Ferrous oxide: Add a high-valence manganese-based oxidant to the acid leaching solution after copper removal in step S2 to carry out an oxidation reaction, and obtain an acid leaching solution containing iron ions. S4. Hydrolysis to remove iron and aluminum: Add an alkaline compound to the acid leaching solution containing iron ions described in step S3 to carry out a hydrolysis reaction to remove iron and aluminum ions, and obtain an acid leaching solution and iron and aluminum hydrolysis products after removing iron and aluminum. S5. Extraction of manganese ions: Add the extractant saponified by the saponifying agent to the acid leaching solution after removing iron and aluminum in step S4 and extract to obtain a manganese metal complex organic phase and an extract residue rich in nickel and cobalt metal. S6. Back-extraction of manganese ions: Add sulfuric acid aqueous solution to the organic phase of the manganese metal complex described in step S5 for back-extraction to obtain manganese sulfate aqueous solution and back-extraction residue. The manganese sulfate aqueous solution is then evaporated and concentrated to obtain manganese sulfate compound.

[0009] Further, in step S1, at 20-100℃, sulfuric acid with a concentration of 0.5M-4M and hydrogen peroxide with a mass fraction of 5%-70% are added to the lithium-ion battery black powder. The positive electrode material of the lithium-ion battery is a nickel-cobalt-manganese ternary material. The solid-liquid ratio of the black powder to sulfuric acid and hydrogen peroxide is 1 / 8-1 / 20, and the volume ratio of sulfuric acid to hydrogen peroxide is 2 / 1-10 / 1. The mixture is stirred and reacted for 0.5h-6h. After the reaction is completed, the solid and liquid are separated to obtain an acid leaching solution rich in nickel-cobalt-manganese-lithium organometallic and copper, iron and aluminum impurity metal ions.

[0010] Further, in step S2, iron metal is added to the acid leaching solution described in step S1 at a solid-liquid ratio of 1 / 50-1 / 1000, and the reaction is stirred at 20-50 degrees Celsius for 0.5-6 hours. After the reaction is completed, the solid and liquid are separated to obtain the copper-free acid leaching solution and sponge copper solid.

[0011] Furthermore, in step S2, the ferrous metal is one or more of iron powder, iron filings, iron slag, iron blocks, and iron rods. Typical but non-limiting examples of combinations include: combinations of iron powder and iron filings, combinations of iron slag and iron blocks, and combinations of iron blocks and iron rods.

[0012] Further, in step S3, a high-valence manganese-based oxidant is added to the acid leaching solution after copper removal in step S2 at a solid-liquid ratio of 1 / 200-1 / 5000, and the reaction is stirred at a temperature of 20-50°C for 0.5-6 hours. After the reaction is completed, an acid leaching solution containing iron ions is obtained.

[0013] Further, in step S3, the high-valent manganese-based oxidant is potassium permanganate and / or sodium permanganate.

[0014] Further, in step S4, an alkaline compound is added to the iron-containing acid leaching solution described in step S3 to adjust the pH to 3.5-6.5. The solution is stirred at 20-70°C for 0.5-24 hours to co-precipitate and remove iron and aluminum ions. After the reaction is completed, the iron and aluminum removed acid leaching solution and iron and aluminum hydrolysis products are obtained.

[0015] Furthermore, in step S4, the alkaline compound is one or more of sodium hydroxide, sodium carbonate, ammonia, and ammonium carbonate. Typical but non-limiting examples of combinations include: combinations of sodium hydroxide and sodium carbonate, combinations of sodium hydroxide and ammonia, or combinations of sodium carbonate, sodium bicarbonate, and ammonium carbonate, etc.

[0016] Further, in step S5, an extractant saponified by a saponifying agent is added to the acid leaching solution after iron and aluminum removal in step S4. The extractant is P204 and sulfonated kerosene, with a volume ratio of P204 to sulfonated kerosene of 1 / 2 to 1 / 10 and a saponification rate of 15% to 30%. The mixture is uniformly mixed at 20-40°C for 5 min to 120 min, and after standing and separating, a manganese metal complex organic phase and a nickel-cobalt metal-rich extract residue are obtained.

[0017] Furthermore, in step S5, the saponifying agent is sodium hydroxide.

[0018] Furthermore, in step S5, the volume ratio of the saponified extractant to the acid leaching solution after iron and aluminum removal is 1 / 4 to 4 / 1.

[0019] Further, in step S6, sulfuric acid aqueous solution is added to the organic phase of the manganese metal complex described in step S5, and the mixture is uniformly mixed at 20-40°C for 5 min-120 min. After standing and separating, manganese sulfate aqueous solution and back-extraction residue are obtained. The manganese sulfate aqueous solution is then evaporated and concentrated to obtain manganese sulfate compound.

[0020] Furthermore, in step S6, the concentration of the sulfuric acid aqueous solution is 1.5-4M.

[0021] Further, in step S6, the volume ratio of the sulfuric acid aqueous solution to the manganese metal complex organic phase is 1 / 4 to 4 / 1.

[0022] Beneficial effects (1) This invention provides a method for the synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder. Different removal methods are designed based on the characteristics of different impurity metals. For copper ions hydrolyzed at higher pH, iron displacement reaction is preferentially used for removal; for Fe present in the acid leaching system... 2+ and Fe 3+ And the Fe newly introduced due to the substitution reaction 2+ Using high-valence manganese ion salts as oxidants, Fe2+ hydrolyzed at high pH is decomposed. 2+Ion oxidation to Fe hydrolyzed at low pH 3+ Ions, with Al 3+ The ions are removed by co-precipitation. The manganese ions introduced in this purification step, together with the manganese ions in the acid leaching solution, can be preferentially extracted by the P204 extractant, thereby separating them from the nickel, cobalt, and lithium metal ions.

[0023] (2) This invention provides a method for the synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder. Compared with the traditional wet impurity removal and recovery process, this invention introduces high-valence manganese ion salts as oxidants, thereby improving the removal rate of impurity metal ions. The additionally introduced manganese ions will be enriched and recovered through extraction methods.

[0024] (3) This invention provides a method for the synergistic removal of impurities from lithium-ion battery black powder and the extraction of manganese. The final product is an inorganic compound of manganese metal and an extract liquid rich in nickel, cobalt and lithium, which is beneficial for subsequent separation operations and simplifies the purification steps. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method described in this invention. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments.

[0027] Example 1 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The positive electrode material of the battery is NCM 523. The preparation method includes the following steps: S1. Add 4.0 L of 1.5 M sulfuric acid solution to 500 g of lithium-ion battery black powder, then slowly add 0.5 L of 25% hydrogen peroxide solution dropwise. Stir vigorously at 85 degrees Celsius for 3 hours. After the reaction is completed, separate the solid and liquid to obtain the acid leaching solution.

[0028] S2, add 20 g of iron powder to the acid leaching solution obtained in step S1, stir vigorously at 45 degrees Celsius for 2 hours. After the reaction is completed, separate the solid and liquid to obtain copper-free acid leaching solution and sponge copper.

[0029] S3. Add 4g of KMnO4 to the copper-free acid leaching solution obtained in step S2, and stir vigorously at 20 degrees Celsius for 1 hour. After the reaction is completed, an acid leaching solution containing iron ions is obtained.

[0030] S4. Add 15% NaOH solution to the iron-containing acid leaching solution obtained in step S3, adjust the pH to 4.0, and stir vigorously at 20 degrees Celsius for 12 hours. After the reaction is completed, separate the solid and liquid to obtain the purified acid leaching solution and iron-aluminum hydroxide precipitate.

[0031] S5, add an extractant to the acid leaching solution after impurity removal described in step S4, wherein the volume ratio of P204 to sulfonated kerosene in the extractant is 1 / 4; the extractant is saponified with sodium hydroxide, and the saponification rate is 20%; the volume ratio of extractant to acid leaching solution is 1 / 1; then mix uniformly at 30 degrees Celsius for 60 minutes, let stand to separate the layers, and separate the manganese metal complex organic phase and the extract residue rich in nickel and cobalt metal.

[0032] S6. Add a back-extraction agent to the manganese metal complex organic phase described in step S5. The back-extraction agent is a 1.5M sulfuric acid aqueous solution, and the volume ratio of the back-extraction agent to the manganese organic phase is 1 / 1. Then, mix uniformly at 30 degrees Celsius for 60 minutes, allow to stand and separate into layers, and separate to obtain a manganese sulfate aqueous solution and the back-extraction residue. The manganese sulfate aqueous solution is then evaporated and concentrated to obtain a manganese sulfate compound.

[0033] Example 2 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between the preparation method and that in Example 1 is that the concentration of sulfuric acid in step S1 is 3M and the concentration of hydrogen peroxide is 25%, while all other conditions are the same as in Example 1.

[0034] Example 3 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between the preparation method and that in Embodiment 1 is that, except for the addition of 40g of iron slag in step S2, all other conditions are the same as in Embodiment 1.

[0035] Example 4 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between this embodiment and embodiment 3 is that, except for step S2 which involves stirring and reacting at 20 degrees Celsius for 5 hours, all other conditions are the same as in embodiment 3.

[0036] Example 5 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder acid leaching solution. The only difference between this embodiment and Embodiment 1 is that, except for the addition of 4g NaMnO4 in step S3 and vigorous stirring at 40 degrees Celsius for 3 hours, all other conditions are the same as in Embodiment 1.

[0037] Example 6 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between this embodiment and Embodiment 1 is that, except for step S4 where the pH is adjusted to 5.5 and the reaction is carried out with vigorous stirring at 30 degrees Celsius for 6 hours, all other conditions are the same as in Embodiment 1.

[0038] Example 7 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between the preparation method and that of Example 1 is that, except that in step S5, the volume ratio of P204 to sulfonated kerosene in the extractant is 1 / 6, and the extractant is saponified with sodium hydroxide with a saponification rate of 30%, all other conditions are the same as in Example 1.

[0039] Example 8 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between this embodiment and embodiment 7 is that, except for step S5 where the volume ratio of extractant to acid leaching solution is 1 / 2, all other conditions are the same as in embodiment 7.

[0040] Example 9 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between this embodiment and Embodiment 1 is that, except that the back-extraction agent in step S6 is a 3.0 M sulfuric acid aqueous solution and the volume ratio of the back-extraction agent to the manganese organic phase is 1 / 3, all other conditions are the same as in Embodiment 1.

[0041] Example 10 This embodiment provides a method for the synergistic removal of impurities and extraction of manganese metal from lithium-ion battery black powder using acid leaching solution. The only difference between this embodiment and embodiment 9 is that, except for the uniform mixing at 40 degrees Celsius for 20 minutes after step S6, all other conditions are the same as in embodiment 9.

[0042] Comparative Example 1 In this comparative example, the method is the same as in Example 1 except that step S3 is not performed.

[0043] Comparative Example 2 In this comparative example, the method is the same as in Example 1, except that the saponification rate in step S5 is 8%.

[0044] The extracts rich in nickel and cobalt metals obtained from Examples 1-10 and Comparative Examples 1-2 (labeled as L) and manganese sulfate (labeled as S) were analyzed by ICP to determine the content of copper, iron, and aluminum impurities. The results are shown in Table 1 below. Table 1

[0045] As can be seen from Table 1: (1) As can be seen from Examples 1-11, the method for removing impurities from lithium-ion battery black powder and extracting manganese metal provided by the present invention can obtain manganese sulfate and extraction residue with low copper, iron and aluminum impurity content, which is beneficial for subsequent separation and recovery of high-purity nickel, cobalt and lithium valuable metals.

[0046] (2) As can be seen from Example 1 and Comparative Example 1, the high-valence manganese ion oxidation step is the key step in the removal of impurity iron, and it will also affect the subsequent removal of aluminum ions.

[0047] (3) As can be seen from Example 1 and Comparative Example 2, the saponification rate is a relatively important parameter in the extraction of manganese metal by the extraction method. If the saponification rate is too low, the manganese will not be completely extracted, resulting in residual manganese in the extraction liquid.

[0048] In summary, the invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered to be within the protection scope of this invention.

Claims

1. A method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder, characterized in that: The method steps include: S1. The lithium-ion battery black powder is leached with acid to obtain an acid leaching solution rich in nickel, cobalt, manganese, lithium organometallic and copper, iron and aluminum impurity metal ions. S2. Add iron metal to the acid leaching solution described in step S1 to carry out a displacement reaction, and obtain the acid leaching solution after copper removal and sponge copper solid. S3. Add a high-valence manganese-based oxidant to the copper-removed acid leaching solution described in step S2 to carry out an oxidation reaction, thereby obtaining an acid leaching solution containing iron ions. S4. Add an alkaline compound to the acid leaching solution containing iron ions described in step S3 to carry out a hydrolysis reaction to remove iron and aluminum ions, and obtain an acid leaching solution and iron and aluminum hydrolysis products after iron and aluminum removal. S5. Add the saponified extractant to the acid leaching solution after removing iron and aluminum as described in step S4 and extract to obtain a manganese metal complex organic phase and an extract residue rich in nickel and cobalt metal. S6. Add sulfuric acid aqueous solution to the organic phase of the manganese metal complex described in step S5 for back-extraction to obtain manganese sulfate aqueous solution and back-extraction residue. The manganese sulfate aqueous solution is then evaporated and concentrated to obtain manganese sulfate compound.

2. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S1, sulfuric acid with a concentration of 0.5M-4M and hydrogen peroxide with a mass fraction of 5%-70% are added to lithium-ion battery black powder at 20-100℃. The positive electrode material of the lithium-ion battery is a nickel-cobalt-manganese ternary material. The solid-liquid ratio of black powder to sulfuric acid and hydrogen peroxide is 1 / 8-1 / 20, and the volume ratio of sulfuric acid to hydrogen peroxide is 2 / 1-10 / 1. The reaction is stirred for 0.5h-6h. After the reaction is completed, the solid and liquid are separated to obtain an acid leaching solution rich in nickel-cobalt-manganese-lithium organometallic and copper, iron and aluminum impurity metal ions.

3. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S2, iron metal is added to the acid leaching solution described in step S1 at a solid-liquid ratio of 1 / 50 to 1 / 1000. The mixture is stirred and reacted at 20-50 degrees Celsius for 0.5-6 hours. After the reaction is completed, the solid and liquid are separated to obtain the copper-free acid leaching solution and sponge copper solid.

4. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 3, characterized in that: The ferrous metal is one or more of the following: iron powder, iron filings, iron slag, iron blocks, and iron rods.

5. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S3, a high-valence manganese-based oxidant is added to the acid leaching solution after copper removal in step S2 at a solid-liquid ratio of 1 / 200-1 / 5000. The reaction is stirred at 20-50°C for 0.5-6 hours. After the reaction is completed, an acid leaching solution containing iron ions is obtained. In step S3, the high-valence manganese-based oxidant is potassium permanganate and / or sodium permanganate.

6. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S4, an alkaline compound is added to the iron-containing acid leaching solution described in step S3 to adjust the pH to 3.5-6.

5. The solution is stirred at 20-70°C for 0.5-24 hours to co-precipitate and remove iron and aluminum ions. After the reaction is completed, an acid leaching solution and iron and aluminum hydrolysis products are obtained after iron and aluminum removal. The alkaline compound is one or more of sodium hydroxide, sodium carbonate, ammonia, and ammonium carbonate.

7. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S5, an extractant saponified by a saponifying agent is added to the acid leaching solution after iron and aluminum removal in step S4. The extractant is P204 and sulfonated kerosene, with a volume ratio of 1 / 2 to 1 / 10 and a saponification rate of 15% to 30%. The mixture is uniformly mixed at 20-40°C for 5 min to 120 min. After standing and separating, a manganese metal complex organic phase and a residual extract rich in nickel and cobalt metal are obtained.

8. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 7, characterized in that: In step S5, the saponifying agent is sodium hydroxide; the volume ratio of the saponified extractant to the acid leaching solution after iron and aluminum removal is 1 / 4 to 4 / 1.

9. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S6, sulfuric acid aqueous solution is added to the organic phase of the manganese metal complex described in step S5, and the mixture is uniformly mixed at 20-40°C for 5 min-120 min. After standing and separating, manganese sulfate aqueous solution and back-extraction residue are obtained. The manganese sulfate aqueous solution is then evaporated and concentrated to obtain manganese sulfate compound.

10. The method for synergistic removal of impurities and extraction of manganese from lithium-ion battery black powder as described in claim 1, characterized in that: In step S6, the concentration of the sulfuric acid aqueous solution is 1.5-4M; The volume ratio of the sulfuric acid aqueous solution to the manganese metal complex organic phase is 1 / 4 to 4 / 1.

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