Method for preparing secondary battery material from black mass

Abstract

Embodiments of the present disclosure relate to a method for preparing a secondary battery material from black mass. The method for preparing a secondary battery material from black mass, according to one embodiment, comprises: a firing step of firing black mass; a pre-extraction step of dissolving, in water, the black mass fired in the firing step, thereby separating same into a lithium solution and a cake; a first evaporation concentration step of evaporating and concentrating the lithium solution produced in the pre-extraction step, thereby preparing a lithium carbonate crystal; a leaching step of leaching the cake separated out in the pre-extraction step; a first purification step of removing copper and aluminum from the leaching solution produced by means of the leaching step; a post-extraction step of neutralizing the solution obtained from the first purification step, thereby separating same into a lithium solution and a cake (NCM cake) comprising Ni, Co and Mn; and a transfer step of transferring, to a lithium hydroxide preparation step, the lithium carbonate crystal produced by means of the first evaporation concentration step and the lithium solution separated out by means of the post-extraction step.

Description

Method for manufacturing secondary battery materials from black mass

[0001] The present invention relates to a method for manufacturing secondary battery materials of lithium and secondary battery precursor raw materials (nickel (Ni), cobalt (Co), manganese (Mn)) from black mass recovered from secondary battery scrap.

[0002] Research is ongoing to recover lithium contained in black mass recovered from secondary battery scrap. These methods include pre-extraction, where the black mass is subjected to reduction and calcination to transform lithium peroxide into lithium carbonate, which is then distributed and extracted in a lithium aqueous solution. The post-extraction method involves leaching the black mass with a complex sulfate solution and separating and extracting the lithium in a subsequent process.

[0003] The pre-extraction method involves reducing and calcining black mass in a nitrogen atmosphere to reduce the lithium contained in the black mass to lithium carbonate, which is then recovered through a water leaching process. This allows for the recovery of high-purity lithium carbonate with very low impurity concentrations. However, due to the limited lithium reduction rate, the lithium recovery rate is limited to approximately 85%.

[0004] The post-extraction method, which involves extracting black mass with a complex sulfate solution and then separating lithium, simplifies the process. However, due to the high waste rate of lithium caused by process byproducts generated during the various impurity removal processes, the lithium recovery rate remains at around 80%.

[0005] Additionally, there is a problem that the amount of auxiliary materials such as hydrogen peroxide added when extracting black mass in a sulfuric acid solution differs by more than twice depending on whether the black mass is calcined or not.

[0006] The present invention aims to solve problems associated with the process of pre-extracting and post-extracting lithium from black mass, and to improve the recovery rate of lithium and secondary battery precursor metals.

[0007] In order to solve these problems, a method for manufacturing a secondary battery material from black mass according to an embodiment of the present invention comprises: a firing process (S10) for firing black mass; a pre-extraction process (S20) for dissolving the fired black mass from the firing process (S10) in water and separating it into a lithium (Li) solution and a cake; a first evaporation and concentration process (S30) for producing lithium carbonate (Li2CO3) crystals by evaporating and concentrating the lithium (Li) solution produced in the pre-extraction process (S20); a leaching process (S40) for leaching the cake separated from the pre-extraction process (S20); a first pre-extraction process (S50) for removing copper and aluminum from the leaching solution produced by the pre-extraction process (S40); a post-extraction process (S60) for neutralizing the solution from the first pre-extraction process (S50) and separating it into a lithium (Li) solution and a cake (NCM cake) containing Ni, Co, and Mn; and a second pre-extraction process (S30) for separating the lithium (Li) solution and the cake containing Ni, Co, and Mn. It includes a transport process for transporting the generated lithium carbonate (Li2CO3) crystals and the lithium (Li) solution separated by the above-mentioned extraction process (S60) to a lithium hydroxide (LiOH) manufacturing process.

[0008] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention comprises: a phosphate precipitation process (S70) in which phosphoric acid (H3PO4) and sodium hydroxide (NaOH) are added to the lithium (Li) solution separated by the secondary extraction process (S60) to produce a lithium phosphate (Li3PO4) cake; a sulfate manufacturing process (S80) in which lithium carbonate (Li2CO3) crystals produced by the first evaporation and concentration process (S30) and the lithium phosphate (Li3PO4) cake of the phosphate precipitation process (S70) are dissolved with sulfuric acid to produce a lithium sulfate (Li2SO4) solution; a carbonate precipitation process (S90) in which sodium carbonate (Na2CO3) is added to the lithium sulfate (Li2SO4) produced in the sulfate manufacturing process (S80) to precipitate lithium carbonate (Li2CO3); and calcium oxide (CaO) and water are added to the lithium carbonate (Li2CO3). It further includes a lithium hydroxide (LiOH) solution manufacturing process (S100) for manufacturing a lithium hydroxide (LiOH) solution and a second evaporation and concentration process (S110) for evaporating and concentrating the lithium hydroxide (LiOH) solution produced in the hydroxide salt manufacturing process (S100).

[0009] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention further includes a weak acid leaching process (S120) for dissolving the NCM cake produced in the secondary extraction process (S60) with sulfuric acid to produce a solution (NCM solution) containing Ni, Co, and Mn, a second precipitation process (S130) for removing impurities from the NCM solution produced in the weak acid leaching process (S120), and a process (S140) for transporting the NCM solution that has undergone the second precipitation process (S130) to, for example, a factory or facility that produces precursor raw materials.

[0010] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention further includes a process of removing residual sodium salt by repulping the NCM cake produced in the above-described extraction process (S60) at least twice.

[0011] The above first separating process (S50) includes a process of removing copper (Cu) by adding sodium hydrogen sulfide (NaHS) and removing aluminum (Al) by adding sodium hydroxide (NaOH).

[0012] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention further includes a process of evaporating and concentrating the lithium sulfate (Li2SO4) solution produced in the sulfate manufacturing process (S80) to separate it into lithium sulfate (Li2SO4) crystals and a phosphoric acid (H3PO4) filtrate.

[0013] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention further includes a repulping process for removing residual sodium salt from the lithium carbonate (Li2CO3) cake produced in the carbonate precipitation process (S90).

[0014] A method for manufacturing a secondary battery material from black mass according to one embodiment of the present invention further includes a process of removing impurities by adding aluminum sulfate (Al2(SO4)3) to a solution in the sulfate manufacturing process (S80).

[0015] According to the present invention, a high-yield process utilizing black mass recovered from secondary batteries can achieve a lithium (Li) recovery rate of 92% or higher, and a recovery rate of nickel (Ni), cobalt (Co), and manganese (Mn), which are secondary battery raw materials, can achieve a recovery rate of 95% or higher. Furthermore, recycling a large amount of battery byproducts can have the effect of reducing environmental pollution.

[0016] According to the present invention, there is an effect of reducing the amount of raw materials used during sulfuric acid leaching through a process of reduction calcination for lithium pre-extraction.

[0017] According to the present invention, by controlling the number of times and pH of the semen process, impurities can be removed to a concentration for producing a high-purity NCM complex sulfate solution.

[0018] According to the present invention, by combining a dry process, which is a pre-extraction process, and a wet process, which is a post-extraction process, the recovery rate of valuable metals such as nickel (Ni), cobalt (Co), and manganese (Mn) can be improved, and lithium (Li) can be effectively separated from black mass.

[0019] According to the present invention, a process for recovering lithium from a lithium (Li) solution of a post-extraction process having a high impurity content and a process for recovering lithium carbonate (Li2CO3) from a lithium (Li) solution of a pre-extraction process having a relatively low impurity content by evaporation and concentration are separated and operated as separate purification processes, thereby reducing lithium loss in the lithium purification process and saving processing costs.

[0020] Figure 1 is a process diagram for transporting lithium (Li), manufactured through a pre-extraction process and a post-extraction process from black mass, to a lithium hydroxide (LiOH) manufacturing process.

[0021] Figure 2 is a process diagram for manufacturing high-purity lithium hydroxide (LiOH).

[0022] Figure 3 is a process diagram for manufacturing a high-purity NCM (Ni, Co, Mn) solution.

[0023] Hereinafter, the present invention will be described with reference to the drawings.

[0024] Figure 1 is a process diagram for transporting lithium (Li), manufactured through a pre-extraction process and a post-extraction process from black mass, to a lithium hydroxide (LiOH) manufacturing process.

[0025] Firing process (S10)

[0026] This is a process of reducing and calcining black mass in a nitrogen (N2) atmosphere at 800-900℃ for 1-3 hours. The reaction formula within the furnace is as follows (Equation 1).

[0027] 2Li(NCM)O2+ 2CO → Li2CO3+ NCM + (NCM)O + CO2... (Equation 1)

[0028] By calcining black mass in an inert nitrogen atmosphere, lithium (Li) can be converted into a form that can be dissolved in water. During the reduction calcination process of black mass for lithium pre-extraction, some high-oxide compounds (Me2O3, Me=Ni, Co, Mn) are reduced to low-oxide compounds (MeO, Me=Ni, Co, Mn), reducing the amount of auxiliary materials (H2O2, hydrogen peroxide) used during sulfuric acid leaching.

[0029] Pre-extraction process (S20)

[0030] In the calcination process (S10), water is added to the calcined black mass that has been reduced and calcined, and lithium (Li) is extracted and separated at 20 to 30°C for 1 to 3 hours, thereby producing a lithium carbonate (Li2CO3) solution. More than 65% of the total lithium (Li) from the reduced and calcined black mass can be separated using water.

[0031] Through the pre-extraction process (S20), the operating costs and raw material costs of the subsequent process, the phosphate precipitation process (S70), can be reduced, the mixing of impurities into the high-purity lithium hydroxide (LiOH) manufacturing process can be minimized, and the processing costs of the lithium hydroxide (LiOH) manufacturing process can be reduced.

[0032] First evaporation and concentration process (S30)

[0033] This is a process for manufacturing lithium carbonate (Li2CO3) crystals by evaporating and concentrating the residue from the above pre-extraction process (S20).

[0034] Leaching process (S40)

[0035] This is a process in which lithium is pre-extracted in the above pre-extraction process (S20) and the resulting cake is reduced and leached with sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) at 80 to 85°C for 8 hours. The reaction formula is as follows.

[0036] MeO + H2SO4→ MeSO4+ H2O [Me=Ni / Co / Mn] ... (Equation 2)

[0037] Me2O3+ 2H2SO4+ H2O2→ 2MeSO4+ 2H2O + O2... (Equation 3)

[0038] Me + H2SO4→ MeSO4+ H2[Me=Ni / Co / Mn] ... (Equation 4)

[0039] When nickel (Ni), cobalt (Co), and manganese (Mn) are leached from a cake from which lithium (Li) has been pre-extracted through a pre-extraction process (S20), the amount of raw materials used can be minimized and stable process management in a continuous process is possible.

[0040] First regular process (S50)

[0041] This is a primary precipitation process designed to remove impurities such as copper (Cu), aluminum (Al), and silicon (Si) from the leaching solution (sulfate solution) produced in the leaching process (S40) through a simple precipitation reaction, in contrast to solvent extraction, which requires complex equipment configuration, environmental risks, and high processing costs, thereby improving the efficiency of impurity removal.

[0042] The copper (Cu) removal process is a process in which sodium bisulfide (NaHS) is added (1.2 eq) and reacted at 60-80℃ for 4 hours to precipitate out Cu in the solution as CuS. The reaction equation is as follows (Formula 5). Here, the unit eq means equivalent weight, which means a certain amount allocated to each element or compound based on the quantitative relationship of substances in a chemical reaction.

[0043] 2CuSO4+ 2NaHS → 2CuS↓ + Na2SO4+ H2SO4... (Equation 5)

[0044] The de-aluminum (Al) process is a process in which sodium hydroxide (NaOH) is added (pH 4.0) and reacted at 70 to 85°C for 8 hours to precipitate and remove aluminum (Al) as Al(OH)3. The reaction formula is as follows (Equation 6).

[0045] Al2(SO4)3+ 6NaOH → 2Al(OH)3↓ + 3Na2SO4... (Equation 6)

[0046] In the process of aluminum (Al) precipitating as Al(OH)3, some of the Fe and Si are coprecipitated and removed.

[0047] Pepper extraction process (S60)

[0048] This is a process in which the filtrate of the first extraction process (S50) is neutralized (pH 10 to 12) with sodium hydroxide (NaOH) and reacted at 70 to 85°C for 4 hours to precipitate and recover nickel (Ni), cobalt (Co), and manganese (Mn), and lithium (Li) is distributed and separated in the filtrate. In the subsequent extraction process (S60), the precipitation rate of nickel (Ni), cobalt (Co), and manganese (Mn) is 99.9% or more.

[0049] The filtered NCM cake is repulped twice or more to remove residual sodium salts. The sodium (Na) content in the cake is reduced from 3.43% to 0.4%.

[0050] Figure 2 is a process diagram for manufacturing high-purity lithium hydroxide (LiOH).

[0051] The high-purity lithium hydroxide (LiOH) manufacturing process comprises the steps of adding sulfuric acid to lithium carbonate (Li2CO3) recovered through the aforementioned pre-extraction process (S20) and first evaporation and concentration process (S30), and lithium phosphate (Li3PO4) precipitated from the lithium solution separated and recovered through the post-extraction process (S60) to manufacture lithium sulfate (Li2SO4), adding sodium carbonate (Na2CO3) to lithium sulfate to manufacture lithium carbonate (Li2CO3), and then adding calcium oxide (CaO) to lithium carbonate (Li2CO3) to manufacture and evaporate and concentrate a lithium hydroxide (LiOH) solution, which is a process for manufacturing high-purity lithium carbonate (Li2CO3) and high-purity lithium hydroxide (LiOH·H2O) with excellent lithium recovery rates. The specific high-purity lithium hydroxide (LiOH) manufacturing process is as follows.

[0052] First evaporation and concentration process (S30)

[0053] As described above, this is a process for manufacturing lithium carbonate (Li2CO3) crystals by evaporating and concentrating the residue from the pre-extraction process (S20).

[0054] Phosphate precipitation process (S70)

[0055] This is a process to recover lithium (Li) by precipitating it in the form of lithium phosphate (Li3PO4) by adding phosphoric acid (H3PO4) (1.2 eq) to the lithium (Li) solution generated in the secondary extraction process (S60) and reacting it at 70-85°C for 2 hours. Sodium hydroxide (NaOH) is added to neutralize it to pH 10.0-12.0, and the reaction formula is as follows.

[0056] 3Li2SO4+ 2H3PO4→ 2Li3PO4↓ + 3H2SO4... (Equation 7)

[0057] Li2CO3+ H3PO4→ Li3PO4↓ + H2O + CO2... (Equation 8)

[0058] H2SO4+ 2NaOH → Na2SO4+ 2H2O ... (Equation 9)

[0059] Lithium phosphate (Li3PO4) has a lower solubility than lithium carbonate (Li2CO3), so the lithium (Li) precipitation recovery rate (94.0%) is high (the solubility of lithium phosphate (Li3PO4) is Li 0.07 g / L, 25°C, and the solubility of lithium carbonate (Li2CO3) is Li 2.4 g / L, 25°C). The concentration of lithium (Li) in the filtrate of the phosphate precipitation process (S70) is 0.1 g / L, and the lithium loss is 6.0%.

[0060] Preferably, a process (dephosphorusization (P) process) to remove P (0.5 g / l) may be required to purify the filtrate from the phosphate precipitation process (S70). The dephosphorization process can be carried out at 50 to 70°C and pH 5.5 to 6.5 for 4 hours. The reaction formula is as follows.

[0061] Al2(SO4)3+ 2H3PO4→ 2AlPO4+ 3H2SO4... (Equation 10)

[0062] Sulfate manufacturing process (S80)

[0063] This is a process for producing a lithium sulfate (Li2SO4) solution (Li 35 g / l) by leaching a cake containing lithium phosphate (Li3PO4) produced in a phosphate precipitation process (S70) and lithium carbonate (Li2CO3) crystals produced in a first evaporation and concentration process (S30) into sulfuric acid. The temperature is 60 to 80°C, the reaction time is 2 hours, and the pH is 2.0 or lower. The reaction formula is as follows.

[0064] 2Li3PO4+ 3H2SO4→ 3Li2SO4+ 2H3PO4... (Equation 11)

[0065] Li2CO3+ H2SO4→ Li2SO4+ H2O + CO2... (Equation 12)

[0066] The solution (lithium carbonate (Li2CO3) solution) manufactured from the lithium (Li) pre-extraction process (S20) is evaporated and concentrated, and the recovered lithium carbonate (Li2CO3) is fed into the sulfate manufacturing process (S80).

[0067] Since the above lithium carbonate (Li2CO3) does not go through the phosphate precipitation process (S70), the amount of phosphoric acid (H3PO4) and sodium hydroxide (NaOH) used is reduced by more than 40%, and the loss of lithium (Li) distributed as a filtrate of the phosphate precipitation process (S70) is greatly reduced.

[0068] Preferably, the lithium sulfate (Li2SO4) solution produced in the above sulfate production process (S80) can be separated into lithium sulfate (Li2SO4) crystals and a phosphoric acid (H3PO4) filtrate by evaporation and concentration. The phosphoric acid (H3PO4) filtrate can be recycled to the phosphate precipitation process (S70) and used as a lithium precipitation by-product. The evaporation condensate generated in the above evaporation and concentration process can be recycled as a process solution for the lithium (Li) pre-extraction process. Through this, the amount of waste liquid generated outside the system can be reduced and the amount of fresh water introduced into the system can be reduced.

[0069] Carbonate precipitation process (S90)

[0070] This is a process of adding sodium carbonate (Na2CO3) to lithium sulfate (Li2SO4) manufactured in the sulfate manufacturing process (S80) and reacting it at 80-85℃ for 4 hours to precipitate lithium carbonate (Li2CO3). The reaction formula is as follows.

[0071] Li2SO4+ Na2CO3→ Li2CO3↓ + Na2SO4... (Equation 13)

[0072] Preferably, a repulping process may be performed to remove residual sodium (Na) salts from the cake of the carbonate precipitation process (S90). Repulping is performed at 80°C (Li 1.6 g / L) to minimize lithium (Li) loss. The filtrate (Li 1.6 g / L) of the carbonate precipitation process (S90) is recycled to the phosphate precipitation process (S70).

[0073] Preferably, before precipitating lithium carbonate (Li2CO3), impurities (P, Fe, etc.) in the solution of the sulfate manufacturing process (S80) can be removed through a dephosphorization (P) process. By adding aluminum sulfate (Al2(SO4)3) to the solution manufactured in the sulfate manufacturing process (S80) to adjust the pH to 5.0 to 6.0 and reacting at 50 to 70°C for 4 hours, most of the phosphorus (P) can be removed through precipitation, and iron (Fe) and other impurities can also be removed through coprecipitation. The reaction formula is as follows.

[0074] Al2(SO4)3+ 2H3PO4→ 2AlPO4+ 3H2SO4... (Equation 14)

[0075] Hydroxide salt manufacturing process (S100)

[0076] This is a process of converting a lithium carbonate (Li2CO3) cake manufactured in a carbonate precipitation process (S90) into a lithium hydroxide (LiOH) solution by adding calcium oxide (CaO) and water and reacting at 70-80°C for 2 hours. The reaction formula is as follows.

[0077] Li2CO3(s) + CaO(s) + H2O → 2LiOH(aq) + CaCO3(s) ... (Equation 15)

[0078] The conversion rate to lithium hydroxide (LiOH) is more than 95% under conditions where the concentration of lithium (Li) in the solution is up to 10 g / L.

[0079] Preferably, the hydroxide salt manufacturing process (S100) can be performed twice.

[0080] Preferably, a repulping process can be performed to recover lithium (Li) contained in the calcium carbonate (CaCO3) residue produced in the hydroxide salt manufacturing process (S100).

[0081] Second evaporation and concentration process (S110)

[0082] This is a process for manufacturing LiOH·H2O products by evaporating and concentrating the lithium hydroxide (LiOH) solution manufactured in the hydroxide salt manufacturing process (S100) in a nitrogen (N2) atmosphere. The total yield of lithium (Li) up to the LiOH·H2O manufacturing process is over 92%.

[0083] Figure 3 is a process diagram for manufacturing a high-purity NCM (Ni, Co, Mn) solution, and relates to a process for manufacturing an NCM solution by leaching and purifying the cake produced in the secondary extraction process (S60) with sulfuric acid.

[0084] In the first stage of the purification process (S50), the pH is gradually increased to pH 4 to primarily remove impurities, and then in the second stage of the purification process (S130), the pH is adjusted to 5 to remove impurities to a concentration suitable for producing a high-purity NCM complex sulfate solution. The residue from the second stage of the purification process (S130) can be reused in the leaching process (S40), thereby minimizing the distribution of valuable metals (Ni, Co, Mn, and Li) as process byproducts and increasing the recovery rate. The specific process is as follows.

[0085] Mild acid leaching process (S120)

[0086] In the secondary extraction process (S60), the NCM cake from which lithium (Li) is separated is leached with sulfuric acid (H2SO4) (pH 1.5-2.5) at 60-80°C for 4 hours. A small amount of reducing agent can be added to improve the dissolution rate of the NCM cake, and hydrogen peroxide (H2O2) is used as the reducing agent.

[0087] Second regular process (S130)

[0088] This is a secondary purification process to remove copper (Cu) and aluminum (Al) contained in the NCM solution manufactured by the above-mentioned weak acid leaching process (S120) to less than 5 mg / L each. The de-coppering process involves adding 1.2 eq of sodium bisulfide (NaHS) and reacting at 60-80°C for 4 hours. The de-aluminum process involves reacting at pH 4.0-5.5 and temperature 70-85°C for 8 hours.

[0089] NCM solution delivery process (S140)

[0090] The NCM solution from which copper and aluminum have been removed through the second fixed process (S130) is sent to a factory or facility that produces precursor raw materials, for example, and manufactured according to composition.

[0091] Example

[0092] In this example, LiOH·H2O products and NCM solutions were manufactured through the aforementioned processes. Detailed conditions for each process are as follows.

[0093] Firing process (S10) - Firing was performed for 2 hours at a kiln temperature of 900℃ in a nitrogen (N2) atmosphere.

[0094] Pre-extraction process (S20) - Water at 25°C was added to the calcined black mass that was reduced and calcined in the calcination process (S10), and leaching was performed for 2 hours.

[0095] First evaporation and concentration process (S30) - The residue from the pre-extraction process (S20) was evaporated and concentrated.

[0096] Leaching process (S40) - In the pre-extraction process (S20), lithium was pre-extracted, and sulfuric acid and 60% hydrogen peroxide (H2O2) were added to the resulting cake, and leaching was performed at a temperature of 80℃ for 8 hours based on a nickel (Ni) concentration of 100 g / L and a final pH of 3.0 in the filtrate. The amount of hydrogen peroxide (H2O2) added was 5 wt% of the cake raw material.

[0097] First Separation Process (S50) - 1.2 eq of 30% sodium bisulfide (NaHS) was added to the leaching solution prepared in the leaching process (S40), and the copper (Cu) removal process was performed at 70°C for 4 hours. Thereafter, sodium hydroxide (NaOH) was added (pH 4.0), and the aluminum (Al) removal process was performed at 85°C for 8 hours.

[0098] Second extraction process (S60) - Sodium hydroxide (NaOH) was added to the filtrate of the first semen process (S50) to adjust the pH to 11.0, and the separation process was performed at a temperature of 85℃ for 4 hours.

[0099] Phosphate precipitation process (S70) - 1.2 eq of 85% phosphoric acid (H3PO4) was added to the lithium (Li) solution generated in the post-extraction process (S60), and sodium hydroxide (NaOH) was added to adjust the pH to 11.0. The precipitation process was performed for 2 hours at 70°C. In addition, 1.5 eq of aluminum sulfate (Al2(SO4)3) was added to purify the filtrate generated in the precipitation process, and the dephosphorization (P) process was performed for 4 hours at pH 6.0 and 60°C.

[0100] Sulfate Manufacturing Process (S80) - 1.1 eq of sulfuric acid was added to a cake containing lithium phosphate (Li3PO4) produced in a phosphate precipitation process (S70) and lithium carbonate (Li2CO3) crystals produced in a first evaporation and concentration process (S30) based on a lithium (Li) concentration of 35 g / L, and the process was performed for 2 hours under pH<2.0 conditions. In addition, the lithium sulfate (Li2SO4) solution produced in the sulfate manufacturing process (S80) was evaporated and concentrated to separate lithium sulfate (Li2SO4) crystals and a phosphoric acid (H3PO4) filtrate.

[0101] Carbonate precipitation process (S90) - 1.2 eq of sodium carbonate (Na2CO3) was added to lithium sulfate (Li2SO4) produced in the sulfate production process (S80), and the precipitation process was performed at a temperature of 85℃ for 4 hours.

[0102] In the lithium carbonate (Li2CO3) cake manufactured in the carbonate precipitation process (S90), 1.05 eq of calcium oxide (CaO) and water were added, and the process was performed at a temperature of 70°C for 2 hours.

[0103] Second evaporation and concentration process (S110) - The lithium hydroxide (LiOH) solution manufactured in the hydroxide salt manufacturing process (S100) was evaporated and concentrated in a nitrogen (N2) atmosphere.

[0104] Mild acid leaching process (S120) - In the secondary extraction process (S60), 1.0 eq of sulfuric acid (H2SO4) and 60% hydrogen peroxide (H2O2) were added to the NCM cake from which lithium (Li) was separated, and the leaching process was performed in an amount of 5 wt% of the NCM cake.

[0105] Second Separation Process (S130) - 1.2 eq of 30% sodium bisulfide (NaHS) was added to the NCM solution manufactured by the weak acid leaching process (S120), and a copper (Cu) removal process was performed at 60°C for 4 hours. Thereafter, sodium hydroxide (NaOH) was added to adjust the pH to 5.0, and a aluminum (Al) removal process was performed at 85°C for 8 hours.

[0106] As a result of performing the process according to this example, lithium hydroxide (LiOH) corresponding to 92% of the amount of lithium (Li) contained in black mass could be recovered, which is a higher recovery rate than the lithium recovery rate (85%) through the conventional pre-extraction method and the lithium recovery rate (80%) through the post-extraction method.

[0107] In addition, as a result of performing the process according to this example, 95% of nickel (Ni), cobalt (Co), and manganese (Mn) contained in the black mass could be recovered.

[0108] While the present invention has been described in connection with certain embodiments herein, it should be understood that various modifications and variations can be made without departing from the spirit and scope of the invention, as understood by those skilled in the art. Furthermore, such modifications and variations are intended to fall within the scope of the claims appended to this specification.

Claims

1. Firing process for sintering black mass (S10); A pre-extraction process (S20) in which the calcined black mass calcined from the above calcination process (S10) is leached with water to separate it into a lithium (Li) solution and a cake; A first evaporation and concentration process (S30) for producing lithium carbonate (Li2CO3) crystals by evaporating and concentrating the lithium (Li) solution produced in the above pre-extraction process (S20); An leaching process (S40) for leaching the cake separated in the above pre-extraction process (S20); A first leaching process (S50) for removing copper and aluminum from the leaching solution produced by the above leaching process (S40); A post-extraction process (S60) in which the solution from the first fixed-liquid process (S50) is neutralized and separated into a lithium (Li) solution and a cake (NCM cake) containing Ni, Co, and Mn; and A method for manufacturing a secondary battery material from black mass, comprising a transfer process for transferring lithium carbonate (Li2CO3) crystals produced by the first evaporation and concentration process (S30) and lithium (Li) solution produced by the second extraction process (S60) to a lithium hydroxide (LiOH) manufacturing process.

2. In paragraph 1, A phosphate precipitation process (S70) in which phosphoric acid (H3PO4) and sodium hydroxide (NaOH) are added to the lithium (Li) solution produced by the above-mentioned extraction process (S60) to produce a lithium phosphate (Li3PO4) cake; A sulfate production process (S80) in which lithium carbonate (Li2CO3) crystals produced by the first evaporation and concentration process (S30) and the lithium phosphate (Li3PO4) cake of the phosphate precipitation process (S70) are leached with sulfuric acid to produce a lithium sulfate (Li2SO4) solution; A carbonate precipitation process (S90) in which sodium carbonate (Na2CO3) is added to lithium sulfate (Li2SO4) produced in the above sulfate manufacturing process (S80) to precipitate lithium carbonate (Li2CO3); A lithium hydroxide salt manufacturing process (S100) for manufacturing a lithium hydroxide (LiOH) solution by adding calcium oxide (CaO) and water to the above lithium carbonate (Li2CO3); and A method for manufacturing a secondary battery material from black mass, comprising a second evaporation and concentration process (S110) for evaporating and concentrating a lithium hydroxide (LiOH) solution produced in the above hydroxide salt manufacturing process (S100).

3. In paragraph 1 or 2, A weak acid leaching process (S120) for producing a solution (NCM solution) containing Ni, Co, and Mn by leaching the NCM cake produced in the above-mentioned extraction process (S60) with sulfuric acid; A second distillation process (S130) for removing impurities from the NCM solution produced in the above weak acid leaching process (S120); A method for manufacturing a secondary battery material from black mass, further comprising a step (S140) of sending the NCM solution that has undergone the second regular process (S130) to a factory that produces precursor raw materials.

4. In paragraph 3, A method for manufacturing a secondary battery material from black mass, further comprising a process of removing residual sodium salt by repulping the NCM cake produced in the above-mentioned extraction process (S60) at least twice.

5. In paragraph 1 or 2, The above first fixed process (S50) is a method for manufacturing a secondary battery material from black mass, which includes a process of removing copper (Cu) by adding sodium hydrogen sulfide (NaHS) and removing aluminum (Al) by adding sodium hydroxide (NaOH).

6. In paragraph 2, A method for manufacturing a secondary battery material from black mass, further comprising a process of evaporating and concentrating the lithium sulfate (Li2SO4) solution produced in the above sulfate manufacturing process (S80) to separate it into lithium sulfate (Li2SO4) crystals and a phosphoric acid (H3PO4) filtrate.

7. In paragraph 2, A method for manufacturing a secondary battery material from black mass, further comprising a repulping process for removing residual sodium salt from the lithium carbonate (Li2CO3) cake produced in the above carbonate precipitation process (S90).

8. In paragraph 2, A method for manufacturing a secondary battery material from black mass, further comprising a step of removing impurities by adding aluminum sulfate (Al2(SO4)3) to the solution in the above sulfate manufacturing process (S80).