Method for removing Fe3+ and Al3+ from a ternary lithium battery black powder acid leaching solution

Abstract

The application discloses a method for removing Fe 3+ and Al 3+ from a ternary lithium battery black powder acid leaching solution, and belongs to the technical field of lithium battery recycling. The pH of the ternary lithium battery black powder acid leaching solution is adjusted to a range of 3.5-6.5, a solid-phase conversion agent (carbonate and / or hydroxide of Ni, Co, Mn or Li) and an oxidizing agent are added, and the reaction is carried out by being heated to 60-95 DEG C, and then solid-liquid separation is performed, so that the purified solution from which Fe and Al are removed is obtained. The method can control the slow increase of the pH of the system by using the solid-phase conversion agent and combining a special initial pH and temperature environment, so that the generation and growth of Fe(OH)3 / Al(OH)3 crystal nuclei are achieved. Not only can the method achieve the purpose of purifying and removing Fe 3+ and Al 3+ from the ternary lithium battery black powder acid leaching solution and avoiding the loss of useful metal ions, but also the generated Fe(OH)3 / Al(OH)3 crystal has a good crystal form and is easy to filter and separate, so that the subsequent separation process flow is simplified.

Description

Technical Field

[0001] This invention relates to a method for removing Fe from the acid leaching solution of ternary lithium battery black powder. 3+ And Al 3+ This method belongs to the field of waste lithium battery recycling technology. Background Technology

[0002] In addition to the main components such as Ni, Co, Mn, and Li, ternary lithium battery black powder also contains impurities such as Cu, Al, and Fe introduced during the crushing and sorting process of waste batteries. According to the group standard for black powder production from recycled waste lithium batteries (T / ATCRR3302021) and the national standard for recycled black powder for lithium batteries (GB / T 45203-2024), the main components of ternary lithium battery black powder are: Ni + Co 25~45%, Mn 10~20%, and Li 3~6%, while the impurity components are: Cu 1~3%, Al 2~4%, and Fe 0.5~1.0%.

[0003] Wet leaching is the mainstream method for the comprehensive utilization of black powder from ternary lithium batteries. The specific process includes: black powder pulping, acid leaching of the slurry, purification of the leaching solution, and extraction / precipitation separation of Ni, Co, Mn, Li, etc., from the purified solution. After acid leaching of the ternary lithium battery black powder, both the main components and impurities are basically transferred to the leaching solution (referred to as "acid leaching solution"). Ni in the acid leaching solution... 2+ Co 2+ Mn 2+ and Li + It has a high concentration and is a recyclable valuable element, while Cu... 2+ Fe 3+ Al 3+ The concentration is relatively low, and it belongs to the category of coexisting impurity elements, requiring removal through purification technology. Among them, Fe... 3+ And Al 3+ The purification of black powder from ternary lithium batteries has always been a major factor restricting the efficient and comprehensive utilization of this black powder.

[0004] Currently, the Fe in the acid leaching solution of ternary lithium battery black powder 3+ And Al 3+ The purification and removal technologies are all based on the removal of Fe from hydrometallurgical leaching solutions containing heavy metals (such as Zn, Mn, etc.). 3+ The main processes include: the sodium ferruginous iron oxide process, the hydroxide precipitation process, and the goethite process. The sodium ferruginous iron oxide process is the most stable, but it produces the largest amount of slag, which carries Ni, Co, Mn, and Li, resulting in significant losses of valuable components. The hydroxide precipitation process controls the pH value of the leachate to remove Fe... 3+ And Al 3+The iron oxide is converted into Fe(OH)3 and Al(OH)3 for removal. The main problem with this method is that both Fe(OH)3 and Al(OH)3 have poor settling and filterability. In particular, once Fe(OH)3 forms a gel-like substance, liquid-solid separation becomes impossible. The goethite method addresses this by synergistically controlling the temperature (≥90℃) and pH of the reaction system to allow Fe... 3+ And Al 3+ The Fe(OH)3 and Al(OH)3 precipitates initially formed slowly lose a water molecule and are transformed into larger and more stable FeOOH (goethite) and AlOOH (alloyed goethite) phases, which greatly improves the settling and filterability of the precipitate particles. However, this method requires very strict process control and a long time to maintain the high temperature of the solution, resulting in a large amount of water evaporation, which will aggravate the precipitation behavior of Ni, Co, and Mn and lead to the loss of Ni, Co, and Mn.

[0005] Hydroxide precipitation is a widely used method in the industry for removing Fe. 3+ And Al 3+ Technology that improves the settling and filterability of Fe(OH)3 and Al(OH)3 or generates other precipitated particles with better settling properties is a method for removing Fe from the leachate of ternary lithium battery black powder. 3+ And Al 3+ Technical challenges urgently need to be addressed. Meanwhile, improvements in the sedimentation and filterability of Fe(OH)3 and Al(OH)3 can reduce the entrainment or co-precipitation of Ni, Co, and Mn, thereby improving the economics of recycling ternary lithium battery black powder. Summary of the Invention

[0006] To address the existing method of removing Fe from the acid leaching solution of ternary lithium battery black powder... 3+ And Al 3+ The present invention aims to provide a method for removing Fe from the acid leaching solution of ternary lithium battery black powder. 3+ And Al 3+ This method, using a solid-phase conversion agent combined with a specific initial pH and temperature environment, can achieve the generation and growth of Fe(OH)3 / Al(OH)3 crystal nuclei by controlling the slow increase of the system pH. This method not only achieves the Fe... 3+ And Al 3+ The purpose of purification and removal is to avoid the loss of useful metal ions due to entrainment. Moreover, the generated Fe(OH)3 / Al(OH)3 crystals have a good crystal form, are easy to filter and separate, and simplify the subsequent separation process.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a method for removing Fe from the acid leaching solution of ternary lithium battery black powder. 3+ And Al 3+The method involves adjusting the pH of the acid leaching solution of ternary lithium battery black powder to the range of 3.5 to 6.5, adding a solid-phase conversion agent and an oxidant, and heating the solution to 60 to 95°C for reaction. After solid-liquid separation, a purified solution free of iron and aluminum is obtained. The solid-phase conversion agent includes at least one carbonate and / or hydroxide of Ni, Co, Mn, and Li.

[0008] The present invention provides a method for removing Fe from the acid leaching solution of ternary lithium battery black powder. 3+ And Al 3+ The method has Fe 3+ And Al 3+ It has good removal effect, and Ni, Co, Mn, Li, etc. are easily separated due to low metal loss and good impurity filtration performance. Conventional hydroxide precipitation methods, whether adding soluble liquid alkali (such as ammonia, sodium hydroxide, or potassium hydroxide) or alkaline soluble salts (such as sodium carbonate / potassium / ammonium, sodium bicarbonate / potassium / ammonium, etc.), cannot avoid the phenomenon of large pH fluctuations and local high alkalinity concentration of the precipitant. According to the crystallization kinetics of precipitation reaction, when a metastable state is formed in the precipitation reaction system, a large number of Fe(OH)3 and Al(OH)3 crystal nuclei will be generated in a very short time, which will then explosively produce extremely small Fe(OH)3 and Al(OH)3 particles, resulting in poor sedimentation and filtration of Fe(OH)3 and Al(OH)3, making liquid-solid separation difficult. The theoretical basis for the above phenomenon is that the K of Fe(OH)3 and Al(OH)3... SP 1.1×10 -36 and 1.3×10 -33 According to the quantitative analysis criteria for complete precipitation, the ion concentration is ≤10. -5 mol / L indicates complete precipitation. That is, after the precipitation reaction reaches its endpoint, the residual Fe in the system... 3+ And Al 3+ The concentrations were ≤0.56 mg / L and 0.27 mg / L, respectively; via Fe 3+ / Al 3+ Ksp calculations for hydroxide precipitation show that, in Fe... 3+ And Al 3+ At concentrations of 0.56 mg / L and 0.27 mg / L, Fe 3+ And Al 3+ The OH groups required to form Fe(OH)3 and Al(OH)3 - The concentrations were 1.69 × 10⁻⁶. -11 mol / L and 5.07×10 -10 mol / L; obviously such a low concentration of OH -Simply adjusting the feeding rate of the alkali solution or increasing the stirring intensity of the reaction system is insufficient to achieve this. Theoretically, a low concentration of OH- can be achieved by infinitely diluting the alkali solution. - This would cause the reaction system to expand rapidly, greatly diluting the Ni. 2+ Co 2+ Mn 2+ and Li + The concentration of such concentrations is meaningless in actual production.

[0009] The key to this invention lies in first strictly adjusting the pH of the acid leaching solution of ternary lithium battery black powder to a certain weakly acidic range, and then adding a solid-phase conversion agent that can slowly dissolve in a weakly acidic environment and at a suitable temperature, thereby uniformly and slowly releasing a low concentration of OH. - To neutralize the H in the acid leaching solution + This causes the pH in the acid leaching solution to gradually increase, thereby precipitating Fe in the acid leaching solution. 3+ And Al 3+ And low concentrations of slowly increasing OH - This ensures a minimal nucleation rate for Fe(OH)3 and Al(OH)3, preventing the explosive growth of fine Fe(OH)3 and Al(OH)3 crystal nuclei. It promotes particle growth, effectively improving the settling and filterability of Fe(OH)3 and Al(OH)3 precipitates, and can also inhibit Ni... 2+ Co 2+ Mn 2+ and Li + Losses occur when Fe(OH)3 and Al(OH)3 crystals enter the reaction system. Simultaneously, the solid-phase conversion agent coexisting in the reaction system can promptly neutralize Fe. 3+ And Al 3+ The formation of Fe(OH)3 and Al(OH)3 precipitates releases H. + This keeps the pH of the reaction system constant at Fe 3+ And Al 3+ The precipitation reaches the required range. This synergistic process, coupled with "neutralization / precipitation-reneutralization / reprecipitation," avoids the back dissolution of Fe(OH)3 and Al(OH)3, and also ensures that Fe... 3+ And Al 3+ It has a deep purification effect.

[0010] The key technical guiding principle of this invention lies in the fact that although the solid-phase conversion agent is poorly soluble or only slightly soluble in water, it can slowly release extremely low concentrations of OH through ionization or hydrolysis. -Because the solid-phase conversion agent is sparingly or only slightly soluble in water, it remains in solid form throughout the entire impurity removal process, effectively neutralizing the H₂ released from the formation of Fe(OH)₃ and Al(OH)₃. + This method avoids the drawbacks of the dropwise addition of liquid alkali or alkaline solution to form hydroxide precipitation, which has large pH fluctuations and locally high alkalinity of the precipitant. It maintains the pH value of the reaction system within a reasonable and constant range, allowing the following reactions to continue:

[0011] ① MeCO3(s) + H2O ≒ Me 2+ +CO2+2OH - (MeCO3 represents a sparingly soluble or slightly soluble carbonate in water, where Me is one or more of Ni, Co, Mn, and Li, and its hydrolysis reaction produces trace amounts of OH.) - );

[0012] ② MeCO 3(S) ≒Me 2+ +CO3 2- (The micro-ionization process of MeCO3);

[0013] ③ CO3 2- +H₂O≒HCO₃ - +OH - (CO3) 2- (hydrolysis process)

[0014] ④ HCO3 - +H₂O≒H₂CO₃+OH - (HCO3) - (hydrolysis process)

[0015] ⑤ Me(OH)2(s)≒Me 2+ +2OH - (Me(OH)2 represents a hydroxide that is sparingly or slightly soluble in water, where Me is one or more of Ni, Co, and Mn, and it ionizes to produce trace amounts of OH-) - );

[0016] ⑥ Fe 3+ / Al 3+ +3OH - ≒Fe(OH)3 / Al(OH)3(s)(Fe 3+ / Al 3+ (Direct precipitation process);

[0017] ⑦ Fe 3+ / Al 3+ +3H₂O≒Fe(OH)₃ / Al(OH)₃(s)+3H + (Fe) 3+ / Al3+ (Hydrolysis and precipitation process)

[0018] ⑧ MeCO3+2H + ≒Me 2+ +H2O+CO2 (MeCO3 neutralizes Fe) 3+ / Al 3+ The precipitation process generates trace amounts of H. + );

[0019] ⑨ Me(OH)2+2H + ≒Me 2+ +2H₂O (Me(OH)₂ neutralizes Fe) 3+ / Al 3+ The precipitation process generates trace amounts of H. + );

[0020] Combining the above reactions, we get:

[0021] ⑩ 2Fe 3+ / Al 3+ +3MeCO3+3H2O≒2Fe(OH)3 / Al(OH)3↓+3CO2+3Me 2+ ;

[0022] And / or ⑪ 2Fe 3+ / Al 3+ +3Me(OH)2≒2Fe(OH)3 / Al(OH)3↓+3Me 2+ ;

[0023] As can be seen from the above reaction equations: on the one hand, this method involves the reaction of MeCO3 / Me(OH)2 with H... + The reaction consumes Fe. 3+ / Al 3+ H produced by hydrolysis precipitation + This inhibited the continuous decrease in system pH caused by reaction ⑦, ensuring the continuous generation of Fe(OH)3 / Al(OH)3 and effectively regulating the growth rate of Fe(OH)3 / Al(OH)3 crystals. On the other hand, the solid-phase conversion agents MeCO3 and / or Me(OH)2 can provide attachment sites for the generated Fe(OH)3 / Al(OH)3 crystals, which is also conducive to the growth of newly formed Fe(OH)3 / Al(OH)3 crystals, thereby improving the settling and filterability of Fe(OH)3 / Al(OH)3 precipitates.

[0024] The solid-phase conversion agents used in this invention are, for example, manganese carbonate, cobalt carbonate, nickel carbonate, lithium carbonate, manganese hydroxide, nickel hydroxide, and cobalt hydroxide. These solid-phase conversion agents do not introduce new impurity elements and are relatively stable in a weakly acidic environment, enabling the slow release of OH-. - The purpose.

[0025] As a preferred embodiment, the pH of the ternary lithium battery black powder acid leaching solution is adjusted to the range of 4.0 to 4.5.

[0026] As a preferred embodiment, the amount of solid-phase conversion agent added to the acid leaching solution of ternary lithium battery black powder is 10~35 g / L. When the amount of solid-phase conversion agent is too low, it is difficult to achieve Fe... 3+ And Al 3+ The purpose of deep purification is that if the amount of solid-phase conversion agent is too high, it will react with Fe. 3+ And Al 3+ The solid-phase conversion agent is added to the precipitate residue together, which increases the application cost. As a preferred solution, the amount of solid-phase conversion agent added to the acid leaching solution of ternary lithium battery black powder is 15~30g / L.

[0027] As a preferred embodiment, the solid-phase conversion agent is added in multiple batches. More preferably, it is added in 3 to 5 batches. Adding it in multiple batches or slowly ensures the pH stability of the system.

[0028] As a preferred embodiment, the oxidant includes at least one of the following: hydrogen peroxide, thiosulfate, ozone, peroxyanionate, oxygen, and air. As a more preferred embodiment, the amount of oxidant used is 1.0 to 3.0 times the theoretical amount, wherein the theoretical amount is measured as the molar amount of oxidant required to completely convert divalent ferrous ions to trivalent ferric ions. To ensure a better oxidation effect and to avoid introducing impurities, the oxidant is further preferably at least one of hydrogen peroxide, ozone, oxygen, and air. The amount of oxidant used is further preferably 1.2 to 2.0 times the theoretical amount.

[0029] As a preferred embodiment, the reaction conditions are: temperature 75~85℃ and time 1.0~10.0 hours. As a more preferred embodiment, the reaction time is 3.0~5.0 hours. Within the preferred temperature range, not only can the dissolution rate of the solid-phase conversion agent be guaranteed, but the crystallization properties of Fe(OH)3 / Al(OH)3 can also be improved, resulting in better crystals. Furthermore, the grain size of Fe(OH)3 / Al(OH)3 can be controlled by adjusting the reaction time.

[0030] The initial pH of the ternary lithium battery black powder acid leaching solution of the present invention can be adjusted by using common water-soluble inorganic alkalis, such as ammonia, sodium hydroxide or potassium hydroxide, or alkaline soluble salts (such as sodium carbonate / potassium / ammonium, sodium bicarbonate / potassium / ammonium, etc.) or a combination of at least two of these alkaline substances.

[0031] The method for removing iron and aluminum from the acid leaching solution of ternary lithium battery black powder according to the present invention includes the following steps:

[0032] 1) Add a certain amount of pH adjuster to the acid leaching solution to adjust the pH value of the solution to the range of 3.5~6.5, and label the resulting solution as solution A;

[0033] 2) Add the solid phase conversion agent to solution A in 3 to 5 portions at a concentration of 10 to 35 g / L, stir well, and obtain slurry solution B containing solid phase conversion agent;

[0034] 3) Oxidize Fe 2+ to Fe 3+ Add 1.0 to 3.0 times the theoretical dosage of oxidant to slurry solution B, stir and react, so that Fe 2+ All oxidized to Fe 3+ The slurry solution C is obtained;

[0035] 4) Raise the temperature of the slurry C to 60~95℃, stir and react for 1.0~10.0 hours, then separate the liquid and solid to obtain the Fe-removed product. 3+ And Al 3+ Purification liquid.

[0036] Compared to existing conventional hydroxide precipitation methods for removing Fe from acid leaching solutions 3+ And Al 3+ The technical solution of this invention has the following significant advantages:

[0037] 1) By using a sparingly soluble or slightly soluble "solid-phase conversion agent" in the reaction system, the pH value of the reaction system is kept constant, thus ensuring the Fe concentration in the purified solution is maintained. 3+ And Al 3+ The concentration can easily reach the technical specifications, thus completing the Fe... 3+ And Al 3+ Highly efficient and stable removal.

[0038] 2) Through the micro-ionization or micro-hydrolysis process of the "solid-phase conversion agent", low concentrations of OH can be released slowly and continuously in a controllable manner. - This reduces the nucleation rate of Fe(OH)3 and Al(OH)3, which is beneficial to their grain growth and solves the problem of difficult liquid-solid separation of iron and aluminum slag.

[0039] 3) By using a "solid-phase conversion agent" in the reaction system, the pH of the system can be stably maintained between 4.0 and 5.5 during the isothermal reaction process, ensuring the Fe... 3+ And Al 3+ Complete precipitation of Fe was achieved. 3+ And Al 3+ It has a removal efficiency of no less than 99%, and can also inhibit the loss of Ni, Co, Mn, Li and other substances by entering Fe(OH)3 and Al(OH)3.

[0040] 4) Based on the characteristic that "solid phase conversion agent" is poorly soluble or slightly soluble in water, its addition process will not cause the problem of excessive local alkalinity in the reaction system. It is simple to operate and highly controllable. Detailed Implementation

[0041] The following examples are intended to further illustrate the present invention, and not to limit the scope of protection of the claims of the present invention.

[0042] Example 1

[0043] Take 4.0 L of acid leaching solution, first add 100 mL of 5% sodium hydroxide solution to adjust the pH to 4.31, then add 80 g of manganese carbonate, stir well, and then add 20 mL of hydrogen peroxide solution dropwise until Fe... 2+ All oxidized to Fe 3+ The temperature was raised to 80℃, and the reaction was stirred for 4.0 h, while monitoring the pH changes of the reaction system. Subsequently, liquid-solid separation was performed to obtain 3900 mL of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0044] Example 2

[0045] The amount of manganese carbonate was adjusted to 60g, and other operating procedures and reagent consumption were the same as in Example 1, finally yielding 3920mL of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0046] Example 3

[0047] Replace 80g of manganese carbonate with 80g of nickel carbonate. All other operations and reagent consumption remained the same as in Example 1, resulting in 3850mL of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0048] Example 4

[0049] Take 4.0 L of acid leaching solution, add 60 mL of 10% sodium hydroxide solution to adjust the pH to 4.22, then add 110 g of manganese hydroxide, stir well, and then bubble air in to remove Fe. 2+ All oxidized to Fe 3+The temperature was then raised to 85℃, and the reaction was stirred for 3.0 h, while monitoring the pH changes of the reaction system. Subsequently, liquid-solid separation was performed to obtain 3.9 L of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0050] Example 5

[0051] Take 4.0 L of acid leaching solution, add 300 mL of 10% sodium carbonate solution to adjust the pH to 4.29, then add 110 g of nickel hydroxide, and then bubble air in to remove Fe. 2+ All oxidized to Fe 3+ The temperature was raised to 90℃, and the reaction was stirred for 6.0 h, while monitoring the pH changes of the reaction system. Subsequently, liquid-solid separation was performed to obtain 4.2 L of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0052] Comparative Example 1

[0053] Without adding any solid-phase conversion agent, the reaction temperature was 80℃. The pH value of the reaction system was adjusted by continuously adding 5% sodium hydroxide solution. During the addition of sodium hydroxide solution, the pH fluctuation and the liquid-solid separation rate at the reaction endpoint were carefully observed. The operation process and monitoring items were the same as in Example 1.

[0054] Experimental phenomena and results: ① During the dropwise addition of sodium hydroxide solution, the pH value reached a maximum of 7.27, exhibiting a significant localized over-alkalinity phenomenon, causing Ni... 2+ Co 2+ Precipitation (the phenomenon of forming a large amount of blue precipitate) and Li + The entrainment loss; however, during the reaction process, if sodium hydroxide solution is not added in time, the H+ released from Fe(OH)3 and Al(OH)3 cannot be neutralized in time. + The system pH value decreased to 3.01, which is unfavorable for Fe. 3+ And Al 3+ ① Deep removal. ② The filtration rate is very slow, the iron-aluminum slag has a high water content, and the filtrate volume is only 3450 mL. ③ Table 2 shows that the Al in this comparative example... 3+ The removal rate was only 79.61%, far lower than the purification effect after the addition of solid phase conversion agent.

[0055] Comparative Example 2

[0056] Take 4.0 L of acid leaching solution, add 15 mL of 32% sodium hydroxide solution to adjust the pH to 4.15, then add 30 g of manganese carbonate, stir well, and then add 20 mL of hydrogen peroxide solution dropwise until Fe... 2+ All oxidized to Fe 3+ The temperature was then raised to 85℃, and the reaction was stirred for 4.5 hours. Liquid-solid separation followed, yielding 3850 mL of purified solution. The composition of the acid leaching solution and the purified solution, as well as the pH changes during the isothermal reaction, are shown in Table 1. (Fe...) 3+ And Al 3+ The removal rates are shown in Table 2.

[0057] Experimental phenomena and results: Liquid-solid separation was relatively easy. However, due to insufficient solid-phase conversion agent dosage, the pH at the reaction endpoint was low, and Fe... 3+ And Al 3+ The purification effect was not ideal, Fe 3+ And Al 3+ Although the removal rate was better than that of Comparative Example 1, it was still lower than that of Example 1.

[0058] Table 1: Component Test Results and pH Monitoring Results of Acid Leaching Solution and Purification Solution

[0059]

[0060] Table 2: Al of Examples 1-5 and Comparative Examples 1-2 3+ and Fe 3+ Purification effect

[0061]

Claims

1. A method for removing Fe from the acid leaching solution of ternary lithium battery black powder 3+ and Al 3+ The method is characterized by: The pH of the acid leaching solution of ternary lithium battery black powder is adjusted to the range of 3.5 to 6.

5. After adding solid phase conversion agent and oxidant and heating to 60 to 95°C for reaction, solid-liquid separation is performed to obtain a purified solution with iron and aluminum removed. The solid phase conversion agent includes at least one carbonate and / or hydroxide of Ni, Co, Mn and Li.

2. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 1 3+ and Al 3+ The method is characterized by: The pH of the ternary lithium battery black powder acid leaching solution is adjusted to the range of 4.0~4.

5.

3. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 1 3+ and Al 3+ The method is characterized by: The amount of solid-phase conversion agent added to the acid leaching solution of ternary lithium battery black powder is 10~35g / L.

4. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 3 3+ and Al 3+ The method is characterized by: The amount of solid-phase conversion agent added to the acid leaching solution of ternary lithium battery black powder is 15~30g / L.

5. A method for removing Fe from acid leaching solution of ternary lithium battery black powder according to claim 1, 3 or 4 3+ and Al 3+ The method is characterized by: The solid-phase conversion agent is added in multiple batches.

6. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 1 3+ and Al 3+ The method is characterized by: The oxidant includes at least one of the following: hydrogen peroxide, thiosulfate, ozone, peroxy acid salt, oxygen, and air. The amount of oxidant used is 1.0 to 3.0 times the theoretical amount, wherein the theoretical amount is measured as the molar amount of oxidant required to completely convert divalent ferrous ions into trivalent ferric ions.

7. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 1 3+ and Al 3+ The method is characterized by: The reaction conditions are: temperature 75~85℃, time 1.0~10.0 hours.

8. The method for removing Fe from the acid leaching solution of ternary lithium battery black powder according to claim 1 3+ and Al 3+ The method is characterized by: The reaction time is 3.0 to 5.0 hours.

Images