KR102130899B1 - A Preparing Method Of Nickel-Cobalt-Manganese Complex Sulfate Solution By Removing Calcium and Silicon Ions Simultaneously In Recycling A Wasted Lithium Secondary Battery Cathode Material - Google Patents

Abstract

The present invention comprises the steps of (a) reducing an anode type lithium secondary battery waste cathode material through a roasting process, (b) leaching and filtering a lithium secondary battery waste cathode material reduced through an roasting process with acid, (c ) (B) selectively hydrolyzing the filtrate separated in step to separate metallic impurities, (d) hydrolyzing the filtrate obtained in step (c) to separate lithium and obtaining a cake, and ( e) A method for preparing a nickel-cobalt-manganese complex sulfate solution comprising the step of leaching and filtering the cake obtained in step (d) with acid.

Description

{A Preparing Method Of Nickel-Cobalt-Manganese Complex Sulfate Solution By Removing Calcium and by removing calcium ions and silicon ions simultaneously in the process of regenerating the waste cathode material of a lithium secondary battery Silicon Ions Simultaneously In Recycling A Wasted Lithium Secondary Battery Cathode Material}

The present invention relates to a method for preparing a nickel-cobalt-manganese complex sulfate solution by simultaneously removing calcium ions and silicon ions in the process of regenerating a waste cathode material of a nickel-cobalt-manganese composite metal oxide of a lithium secondary battery, in more detail In order to remove the nickel-cobalt-manganese composite metal oxide waste cathode material of the lithium secondary battery and prepare the nickel-cobalt-manganese composite sulfate solution, the oxide anode secondary battery waste cathode material is used to remove the calcium ion and silicon ions. It relates to a method of effectively separating and removing calcium ions and silicon ions simultaneously in an acid leaching and hydrolysis process by reduction through a roasting process.

The lithium secondary battery industry is becoming a core technology in various application fields such as smart phones, tablet PCs, electric vehicles, and energy storage devices, so the industrial importance is growing. Lithium secondary batteries, which are mainly applied to portable electronic devices, are being actively researched and developed as concerns about global environment and depletion of fossil fuels are growing, and demand for lithium secondary batteries will increase further as the electric vehicle market expands in the future. Expect.

Defective waste battery scraps generated during the manufacturing process of lithium secondary batteries or waste scraps of lithium secondary batteries that are discarded after use contain useful metals such as nickel, cobalt, and manganese, and have recently developed technologies to recover and recycle these useful resources. This is actively going on.

The nickel-cobalt-manganese composite metal oxide cathode material (hereinafter referred to as'NCM cathode material'), which accounts for more than 60% of the cost of a lithium secondary battery, recycles the waste NCM cathode material, so that the material recovered is It has been reported to have excellent performance, and recently, it has been manufactured and supplied as a ternary (nickel, cobalt, manganese) complex sulfate solution (hereinafter referred to as'NCM complex sulfate solution') that can be recycled simultaneously without separating nickel, cobalt, and manganese, respectively. By doing so, it shows the effect of cost reduction by shortening the process.

Table 1 shows the permissible concentrations of metal impurities allowed in the NCM complex sulfate solution used when preparing the raw material for the precursor of the NCM cathode material of the lithium secondary battery.

ingredient Ni Co Mn Li Mg Ca Zn Cu Fe Na Al Si content
(mg/kg) Content 8~10wt% 300 20 20 One One One 3,000 One 20

Referring to Table 1, it can be confirmed that the concentrations of Ca and Si should be 20 mg/kg or less to be used as a raw material for precursors of NCM cathode materials. Calcium and silicon act as impurities in the NCM complex sulfate solution, and if the concentration of calcium and silicon is high, it can be a factor that degrades the performance of the lithium secondary battery and cannot be used as a precursor raw material for NCM cathode materials.

Table 2 shows the content of metal elements in the raw materials of the waste NCM cathode material of the lithium secondary battery.

Sample Ni Co Mn Li Mg Ca Zn Cu Fe Na Al Si A 251,400 132,900 150,800 75,140 111 133 1.2 0.0 5.0 100 5,775 84 B 231,400 131,000 143,300 64,410 155 147 1.4 0.0 132 371 2,397 67 C 50,140 69,770 167,100 29,940 29 950 90 49,870 5,142 2,475 67,510 2,777 D 49,580 71,120 162,000 31,140 18 1,101 78 50,160 4,903 2,536 59,440 2,647 E 51,610 68,660 168,000 30,110 21 1,289 86 51,150 4,809 2,947 63,620 2,284

[Unit: mg/kg]

Referring to Table 2, it can be seen that the content of calcium and silicon in the raw materials of the waste NCM cathode material varies. To prepare a ternary NCM complex sulfate solution having a concentration of calcium and silicon of 20 mg/kg or less, calcium and There is a problem that only the positive electrode material (Samples A and B) having a silicon concentration of about 300 mg/kg or less should be selectively used, and the remaining waste positive electrode material (Samples C, D and E) cannot be recycled.

Patent Nos. 10-1441421 and 10-1392616 describe a method of manufacturing a ternary NCM complex sulfate solution using a lithium secondary battery waste cathode material, but a method of simultaneously removing calcium and silicon ions There is no disclosure.

After repeating this study, a method of simultaneously lowering the concentrations of calcium and silicon ions at the same time in the process of producing a ternary NCM complex sulfate solution by recycling the waste NCM cathode material of a lithium secondary battery was developed and completed the present invention.

1. Registered Patent Publication No. 10-1441421 (2014.09.11.) 2. Registered Patent Publication No. 10-1392616 (2014.04.19.)

In the present invention, the NCM cathode material is purified by roasting and reducing the waste NCM cathode material in the form of an oxide lithium secondary battery that was selectively used because the content of calcium and silicon was high when preparing the NCM complex sulfate solution. It is intended to provide a method for preparing an NCM complex sulfate solution that can be used as a precursor raw material.

One aspect of the present invention for achieving the above object is (a) reducing the lithium secondary battery waste cathode material in the form of oxide through a roasting process, (b) a lithium secondary battery waste cathode material reduced through the roasting process Step of leaching with acid and filtering, (c) selectively hydrolyzing the filtrate separated in step (b) to separate metallic impurities, (d) hydrolyzing the filtrate obtained in step (c) to lithium It may be a method of producing a nickel-cobalt-manganese complex sulfate solution comprising the steps of separating and obtaining a cake and (e) leaching and filtering the cake obtained in step (d) with acid.

In step (a), the roasting process is performed by adding 0.5 mol to 1.0 mol of activated carbon compared to 1 mol of lithium remaining in the waste cathode material of the lithium secondary battery in the form of oxide, and then mixing the mixture at 600°C to 900°C for 60 minutes to 120 This can be done by holding for a minute.

In the step (b), the leaching process is carried out for 180 minutes to 300 minutes at 75°C to 85°C by introducing hydrogen peroxide as a reducing agent in the presence of hydrochloric acid, and the concentration of hydrogen peroxide is adjusted to 10 wt% to 35 wt% to 0.1 to It can be injected in 5 LPM (Liter Per Minute). After the leaching process, the input amount of hydrochloric acid and hydrogen peroxide can be adjusted so that the pH inside the reactor is 0.8 to 1.8.

The step (c) includes a process in which a sodium carbonate aqueous solution having a content of sodium carbonate (Na ₂ CO ₃ ) of 10 wt% to 25 wt% based on the total weight of the sodium carbonate aqueous solution is added to the reaction tank, and the reaction tank has an internal temperature of 45° C. to 75° C. , PH is 4.5 to 5.5, and the stirring speed may be 180 rpm to 220 rpm. In the step (c), the metallic impurities may include one or more selected from the group consisting of aluminum (Al), iron (Fe), magnesium (Mg), calcium (Ca), and silicon (Si).

The step (d) includes a process in which a sodium carbonate aqueous solution having a content of sodium carbonate (Na ₂ CO ₃ ) of 10 wt% to 25 wt% based on the total weight of the sodium carbonate aqueous solution is added to the reaction tank, and the reaction tank has an internal temperature of 45°C to 75°C. , PH is 6.5 to 8.5, and the stirring speed may be 250 rpm to 350 rpm.

Hydrogen peroxide as a reducing agent in the presence of sulfuric acid in step (e) can be introduced into the reaction tank and leached at 50°C to 85°C for 300 to 500 minutes.

According to the present invention, since the cathode material scrap generated during the lithium secondary battery manufacturing process or the waste cathode material of the lithium secondary battery that is discarded after use is used as a starting material, the content of calcium and silicon is not high, so NCM complex sulfate that can be used in the production of NCM precursors Solutions can be prepared.

In addition, since the content of calcium and silicon is too high (the concentration of Ca or Si is greater than 300 mg/kg), it is possible to recycle and use the waste cathode material of a secondary battery that cannot be recycled and thus contributes to stable supply and demand of materials.

1 is a process diagram of manufacturing a NCM complex sulfate solution using a waste cathode material of a conventional lithium secondary battery.
Figure 2 is a process diagram for producing a NCM composite sulfate solution using a waste cathode material of a lithium secondary battery according to an aspect of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

The present invention is an acid leaching and hydrolysis process by reducing the waste NCM positive electrode material in the form of oxide through a roasting process in order to remove calcium ions and silicon ions when regenerating the waste cathode material of a lithium secondary battery to produce an NCM complex sulfate solution. It relates to a method for effectively separating and removing calcium ions and silicon ions simultaneously.

Figure 2 shows a process diagram for producing an NCM composite sulfate solution that can be used as a precursor for the NCM cathode material using the NCM waste cathode material of a lithium secondary battery according to an aspect of the present invention.

Referring to Figure 2, one aspect of the present invention, (a) lithium secondary battery waste cathode material is roasted to reduce and reduce (S10), (b) by leaching the raw material reduced in step (a) with acid Filtration (S20), (c) selectively hydrolyzing the filtrate separated in step (b) to separate metallic impurities (S30), (d) hydrolyzing the filtrate generated in step (c) By separating the lithium and obtaining a cake (S40) and (e) including the step (S50) of leaching and filtering the cake obtained in step (d) with acid, lithium secondary battery waste cathode material is regenerated by It may be a method of preparing a nickel-cobalt-manganese complex sulfate solution. Hereinafter, it demonstrates in order of a process.

First, the waste NCM cathode material of the lithium secondary battery in the form of oxide may be reduced through a roasting process (a) (S10).

In general, in order to improve the performance of the lithium secondary battery, in the process of manufacturing the NCM positive electrode material, firing, metal oxide input, binder addition, etc. are made, so that the NCM positive electrode material may contain valuable metals and impurities in various oxide forms. This may act as an obstacle in recovering valuable metals by recycling the waste NCM cathode material. In order to remove these disturbing factors, by mixing the pickled-treated activated carbon and performing roasting at a high temperature, the binder added during the production of the cathode material can be removed, and the metal material in the form of oxide bound to oxygen can be reduced. This process is a roasting process.

The roasting process may be performed after mixing the waste cathode material and the carbon material. As the carbon material, a carbon-based powder may be used, and specifically, activated carbon pickled using hydrochloric acid or sulfuric acid may be used. The pickling-treated activated carbon powder has high reactivity with lithium, thereby maximizing the reduction of metallic materials.

Since the lithium secondary battery waste cathode material contains 0.5 mol of carbon compared to 1 mol of lithium, it is preferable to add 0.5 mol to 1.0 mol of 1 mol of lithium to the pickled treated carbon.

The roasting process may be performed by heating at a heating rate of 10° C./min at 600° C. to 900° C. for 60 minutes to 120 minutes (isothermal section). The higher the temperature, the faster the decomposition of the binder can be promoted.

The roasting process can be carried out in a nitrogen atmosphere. The flow rate of nitrogen gas may be 0.1 to 1,000 LPM (Liter Per Minute). After the roasting process (isothermal section) is over, the kiln can be cooled for 300 to 400 minutes. In this cooling section, it is not necessary to maintain a nitrogen atmosphere.

In the roasting process, a non-rotary or rotary kiln can be used, but the use of a rotary kiln is preferable because it can accelerate the roasting reaction.

The reaction scheme in the roasting process is as follows.

2LiMeO ₂ + 2C → Li ₂ CO ₃ + 2Me + CO

Here, Me = Ni, Co, Mn.

Referring to the above reaction formula, it can be confirmed that carbon is converted to carbon monoxide by combining with oxygen present in the anode material in the form of oxide, and at the same time, lithium is converted to lithium carbonate, and nickel, cobalt, and manganese are reduced to metal.

As the waste cathode material, lithium cobalt oxide (LiCoO2), lithium nickel cobalt manganese oxide (LiNiCoMnO2), lithium nickel cobalt aluminum oxide (LiCoAlO2), lithium manganese oxide (LiMnO2) and lithium iron phosphate (LiFePO4) alone or in combination thereof Can be used.

Next, the roasting product obtained after the roasting process is separated by removing lithium through a water leaching process, and the residue is dried to obtain a solid. Specifically, by immersing in H ₂ O at 60° C. to 90° C. and stirring for 60 minutes to 120 minutes, lithium acting as an impurity can be separated and removed when preparing an NCM complex sulfate solution. The solid/liquid concentration ratio is 100 g to 150 g, and the pH at this time can be maintained at a level of 10-11.

Lithium, which has existed in the form of lithium carbonate, may be separated by being leached with a leach solution through a water leaching process. The leached and separated lithium can be used to prepare lithium carbonate, which is a cathode precursor, by various other methods.

The reaction scheme in the water leaching process is as follows.

① Li ₂ O(S) + H ₂ O → 2LiOH(ℓ)·H ₂ O

② Li ₂ CO ₃ (S) + H ₂ O → Li ₂ CO ₃ (ℓ)H ₂ O

The solid material may include a reduced metal, that is, a valuable metal of nickel, cobalt, or manganese, and in addition, impurities such as magnesium, iron, aluminum, sodium, calcium, silicon, and lithium.

Next, after leaching the solid with acid, the filtrate can be filtered to obtain a filtrate (primary acid leaching) (b) (S20).

In step (b), hydrogen peroxide is introduced into the reaction vessel in the presence of hydrochloric acid to perform a leaching process at 75°C to 85°C for 180 minutes to 300 minutes. After leaching, the input amounts of hydrochloric acid and hydrogen peroxide can be adjusted, respectively, so that the pH inside the reactor is 0.8 to 1.8.

In the process of manufacturing a cathode material for a lithium secondary battery, in order to maintain or improve the battery characteristics, a complicated process such as a calcination process, the addition of carbon and other metal oxides, and a thermal fusion after the addition of a binder is performed. It has chemical resistance, which can act as an inhibitor in the recovery of valuable metals with acid. In order to remove the chemical resistance, the leaching efficiency can be maximized by adjusting the concentration and input speed of hydrogen peroxide. In the acid leaching process, hydrogen peroxide not only acts as a reducing agent to reduce metals, but also acts as an oxidizing agent to decompose organic compounds such as binders having chemical resistance. In the process of acid leaching, the concentration of hydrogen peroxide can be adjusted to 10 wt% to 35 wt% and added to 0.1 to 5 LPM (Liter Per Minute) to increase the recovery rate of valuable metals. In addition, the input of hydrogen peroxide must be performed at a constant rate of hydrogen peroxide at a constant concentration throughout the acid leaching process to recover valuable metals with high efficiency.

The filtrate may include target components such as nickel, cobalt, and manganese, and impurity components such as iron, aluminum, magnesium, calcium, and silicon. In the case of the reduced cathode waste material, iron and aluminum may be present in the form of FeCl ₃ and AlCl ₃ by reacting with hydrochloric acid. For reference, in the case of an oxide-type waste cathode material, iron and aluminum react with hydrochloric acid and may exist in the form of FeCl ₂ and AlCl ₂ .

Next, the metallic impurities may be separated by selectively hydrolyzing the filtrate separated in the step (b) (c) (S30).

The separated filtrate includes target components such as nickel, cobalt, and manganese, and impurity components such as iron, aluminum, calcium, and silicon. In this process, the impurity components can be separated and removed through selective hydrolysis.

Step (c), the content of sodium carbonate (Na ₂ CO ₃ ) The sodium carbonate aqueous solution of 10 wt% to 25 wt% based on the total weight of the aqueous solution of sodium carbonate may include a process of introducing into the reaction vessel. At this time, the temperature inside the reactor is 45°C to 75°C, the pH is 4.5 to 5.5, and the stirring speed may be 180 to 220 rpm.

During step (c), at least one of aluminum (Al), iron (Fe), magnesium (Mg), calcium (Ca) and silicon (Si), which are metallic impurities, is selectively hydrolyzed to precipitate in the form of hydroxide, and precipitates The silver can be separated off by filtration.

<Removal of iron and aluminum>

In the case of the reduced cathode waste material, iron and aluminum present in the form of FeCl ₃ and AlCl ₃ react with sodium carbonate to form precipitates of Fe(OH) ₃ and Al(OH) _3, which have a pH of 5.5 or higher. Maintaining can happen. For example, Al(OH) ₃ can be precipitated when the pH is 5.5 or higher. However, if the pH is 5.5 or higher, it is necessary to maintain a low pH because the main valuable metals nickel, cobalt, manganese, such as loss rate higher than 5.5, such a problem by introducing a large amount of hydrogen peroxide in the leachate in the form of an AlCl ₃ AlCl ₂ It can be solved by converting to. That is, when the form of aluminum present in the leach solution is changed from AlCl ₃ to AlCl ₂ , aluminum can be removed at pH 4.8 to 5.2. As a result, it is possible to reduce the loss of valuable metals and also remove aluminum as an impurity.

For reference, in the case of an oxide-type waste cathode material, iron and aluminum present in the form of FeCl ₂ and AlCl ₂ react with sodium carbonate to form precipitates of Fe(OH) ₂ and Al(OH) _2. It can happen below. For example, Al(OH) ₂ may precipitate at pH 4.5-5.5 upon selective hydrolysis.

<Calcium and silicon removal>

In the case of an oxide-type waste cathode material, calcium and silicon are not removed below a standard value even when the pH is 5.5 or higher during selective hydrolysis, whereas in the case of a waste cathode material that is reduced, calcium and silicon are not present even when the pH is 5.0 or less during selective hydrolysis. It can be removed below 20mg/kg, which is a standard that can be used as an NCM complex sulfate solution. In the case of selective hydrolysis, if the pH is 5.5 or more, it is economical to maintain the pH at 5.0 or less because valuable metals such as nickel, cobalt, and manganese increase.

Next, the filtrate obtained in step (c) is hydrolyzed to separate lithium and a cake can be obtained (continuous hydrolysis) (d) (S40).

Step (d), the content of sodium carbonate (Na ₂ CO ₃ ) The sodium carbonate aqueous solution of 10 wt% to 25 wt% based on the total weight of the aqueous sodium carbonate solution may include a step of introducing into the reaction vessel. At this time, the temperature inside the reactor is 45°C to 75°C, the pH is 6.5 to 8.5, and the stirring speed may be 250 to 350 rpm.

In inducing the hydrolysis reaction, sodium carbonate is quantitatively reacted with lithium, nickel, cobalt, and manganese by adding sodium carbonate to the filtrate at a temperature higher than room temperature, preferably 45° C. to 75° C. while stirring the filtrate at 250 rpm to 350 rpm. By doing so, the metal component can be precipitated and separated as a carbonate.

Lithium remaining as an impurity is converted to solubilized lithium carbonate (Li ₂ CO ₃ (ℓ)), and nickel, cobalt, and manganese are precipitated nickel carbonate (NiCO ₃ (s)) and cobalt carbonate (CoCO ₃ (s)) , Converted to manganese carbonate (MnCO ₃ (s)), and lithium can be obtained by separating nickel, cobalt, and manganese into a hydroxide cake.

In addition, magnesium, Mg, iron, Fe, and aluminum introduced in the process of separating and recovering the waste cathode material are added to the waste cathode material for the purpose of improving battery characteristics in addition to the valuable metals of nickel, cobalt, and manganese. Al), silicon (Si) and other metallic impurities may be present. The metallic impurities can be removed by a significant amount through the selective hydrolysis of step (b), but some impurities such as calcium (Ca), magnesium (Mg), silicon (Si), etc. are practically difficult to completely remove.

Additionally, the step (d) may further include a step of leaching the cake obtained with a sulfuric acid solution (secondary acid leaching) (e) (S50).

The metal carbonate cake obtained in step (d) is put in a sulfuric acid solution and re-leaching is performed at 50°C to 85°C for 300 minutes to 500 minutes to prepare a complex sulfate solution that can be used for preparing a positive electrode active material precursor.

The nickel-cobalt-manganese complex sulfate solution thus obtained may be further suitably mixed with one or more of nickel sulfate, cobalt sulfate, and manganese sulfate to adjust the composition of nickel, cobalt, and manganese as desired.

The present invention will be described in more detail through the following examples. However, the present invention is not limited to the embodiments.

1. Preparation and roasting of lithium secondary battery waste cathode material

As a lithium secondary battery waste cathode material, 523 compositions (molar ratio of nickel, comalt, and manganese of 5:2:3) among ternary cathode materials of nickel, cobalt, and manganese were prepared. After removing impurities by pickling with 1% hydrochloric acid as a carbon material, an activated carbon powder dried at 105°C was prepared.

1 kg of the waste cathode material and 1 mole of carbon compared to 1 mole of lithium present in the waste cathode material were mixed into a rotary kiln to maintain a temperature of 800° C. and a roasting process was performed in a nitrogen atmosphere for 60 minutes.

Lithium, which was present in the form of oxide in the waste cathode material, was converted to lithium carbonate by introducing and reducing carbon, and valuable metals such as nickel, cobalt, and manganese, and iron, aluminum, calcium, and silicon, which act as impurities, from oxides It was reduced to a metallic material.

2. Water leaching

In the water leaching process, 500 g of the roasted NCM waste cathode material was immersed in 4,000 ml distilled water, and then stirred at 80° C. for 2 hours to separate lithium. Lithium present in the form of lithium carbonate acts as an impurity in the production of NCM complex sulfate, so it is separated by leaching with a leach solution through water leaching, and the remaining residue is dried to obtain a solid.

In Table 3, the components using the high-frequency inductively coupled plasma (ICP-MS) after the water leaching process for the waste cathode material (A) that has not undergone the roasting process and the waste cathode material (B) that has undergone the roasting process The results were analyzed.

division Ni Co Mn Li Mg Ca Fe Na Al Si A 251,400 96,240 180,000 64,420 108 460 220 847 3,141 680 B 341,000 148,500 137,200 11,110 273 830 4,388 3,317 3,849 1,154

[Unit: mg/kg]

3. Acid leaching

150 g of the waste cathode material reduced through the roasting process was placed in a Pyrex 2 L reactor filled with 400 ml of pure water, and 455 ml of hydrochloric acid corresponding to 1 mol was slowly added while stirring at 300 rpm. After the reaction temperature was added to hydrochloric acid, the temperature rose to 50°C by self-exothermic reaction, and then maintained at 85±10°C using a hot plate. The reaction tank was placed on a hot plate to adjust the temperature. The reaction time was maintained for 180 minutes to perform leaching.

After the introduction of hydrochloric acid, hydrogen peroxide, a reducing agent, was constantly added at a rate of 1 ml/min for 100 minutes. In order to increase the leaching efficiency as hydrogen peroxide, 60 ml of pure water was added to 40 ml of 35 wt% hydrogen peroxide, and a total amount of 100 ml was used. After completion of the reaction, the pH was measured to be 1.20.

Table 4 shows the results of the component analysis of the leachate (AA) obtained by acid leaching of the waste cathode material not subjected to the roasting process and the leachate (BB) obtained by acid leaching of the waste cathode material after the roasting process.

division Ni Co Mn Li Mg Ca Fe Na Al Si AA 23,300 8,830 17,240 5,694 9 27 20 84 295 32 BB 25,920 11,750 10,920 839 25 32 350 150 305 55

[Unit: mg/kg]

4. Selective hydrolysis

The hydrochloric acid leachate was placed in a 2 L Pyrex reaction tank and the temperature was maintained at 50±5° C., 42 ml of 15 wt% sodium carbonate aqueous solution, 1.3 times the equivalent of impurities (aluminum, iron), was slowly added and maintained for 30 minutes, followed by filtration. The residue was washed with pure water to obtain 900 ml of a filtrate including the washing liquid. At this time, the pH was adjusted to 5.0.

After the acidic leaching of the lithium secondary battery waste cathode material (hydrochloric acid and hydrogen peroxide), metal impurities such as Ca and Si as well as Al and Fe were separated and removed through selective hydrolysis (pH 5.0 adjustment), followed by filtration to prepare a filtrate. .

Table 5 shows the filtrate (AAA) obtained after acid leaching and selective hydrolysis of the waste cathode material not subjected to the roasting process and the filtrate (BBB) obtained after acid leaching and selective hydrolysis of the waste cathode material after the roasting process. Component analysis results are shown.

division Ni Co Mn Li Mg Ca Fe Na Al Si AAA 22,270 8,830 16,930 5,420 9 25 0 1,340 0 26 BBB 24,780 11,170 10,730 799 9 8 0 3,370 0 8

[Unit: mg/kg]

Table 6 summarizes the results of the analysis.

division Raw material before roasting process (reduction) Raw material after roasting process (reduction) Acid leach
[mg/kg] After selective hydrolysis
[mg/kg] Removal rate [%] Acid leach
[mg/kg] After selective hydrolysis
[mg/kg] Removal rate [%] Al 295 0 100 305 0 100 Fe 20 0 100 350 0 100 Ca 27 25 11.1 32 8 75.9 Si 32 26 15.6 55 8 85.3

[Unit: mg/kg]

Referring to Table 6, in the case of the waste cathode material that has not been subjected to the roasting process, the concentrations of calcium and silicon after the hydrolysis process are 24 mg/kg and 27 mg/kg, respectively, exceeding the impurity acceptance criteria of the NCM complex sulfate solution, 20 mg/kg. , In the case of the waste cathode material that has undergone the roasting process, the concentrations of calcium and silicon after the hydrolysis process are 7.7 mg/kg and 8.1 mg/kg, respectively, which is less than 20 mg/kg, which is an impurity limit for the NCM complex sulfate solution. .

5. Continuous hydrolysis and preparation of NCM complex sulfate solution

20 wt% aqueous sodium carbonate solution was added to the filtrate based on the total weight of the aqueous sodium carbonate solution. The temperature of the reaction tank was maintained at 60° C., the pH was 7, and the stirring speed was maintained at 350 rpm, to obtain an aqueous solution containing lithium and a hydroxide cake containing nickel, cobalt, and manganese. The cake was placed in a sulfuric acid solution and leached at 70° C. for 400 minutes to prepare a nickel-cobalt-manganese complex sulfate solution.

Table 7 shows the results of component analysis for the composite sulfate solution prepared using the waste cathode material not subjected to the roasting process according to the process flow, and Table 8 shows the composite sulfate prepared using the waste cathode material subjected to the roasting process. The results of the component analysis for the solution are shown according to the flow of the process.

division Raw material before roasting process (reduction) Raw material before reduction 1st hydrochloric acid leaching Selective hydrolysis Continuous hydrolysis Pickling/washing Secondary sulfuric acid leaching Ni 251,400 23,300 22,270 37,860 34,710 45,550 Co 96,240 8,830 8,830 14,390 13,230 17,548 Mn 180,000 17,240 16,930 28,870 26,370 31,801 Li 62,240 5,694 5,420 104 76 96 Mg 108 9 9 11 8 11 Ca 460 27 25 25 24 24 An 2 2 0 0 0 0 Cu 0 0 0 0 0 0 Fe 220 20 0 0 0 0 Na 847 84 1,340 3,250 623 797 Al 3,141 25 0 0 0 0 Si 680 32 26 24 24 26

[Unit: mg/kg]

division Raw material after roasting process (reduction) Raw material after reduction 1st hydrochloric acid leaching Selective hydrolysis Continuous hydrolysis Pickling/washing Secondary sulfuric acid leaching Ni 341,000 25,920 24,780 41,850 38,335 50,570 Co 148,500 11,750 11,170 18,865 17,286 23,352 Mn 137,200 10,920 10,730 18,121 16,621 20,138 Li 11,110 839 799 95 64 83 Mg 273 25 9 8 9 9 Ca 830 32 8 9 7 8 An 22 0 0 0 0 0 Cu 162 0 0 0 0 0 Fe 4,388 350 0 0 0 0 Na 3,317 150 3,370 4,315 738 850 Al 3,849 305 0 0 0 0 Si 1,154 55 8 8 8 9

[Unit: mg/kg]

Referring to Tables 7 and 8, when the roasting process was not performed, the concentrations of calcium and silicon exceeded the allowable concentrations of the metal impurities allowed in the NCM complex sulfate solution, but when the roasting process was performed, the concentrations of the metal impurities were within the allowable concentration range. Can be confirmed.

From the above results, it can be confirmed that when the waste cathode material reduced through the roasting process was used, calcium and silicon could be effectively removed in the selective hydrolysis process, and thus, a complex sulfate solution meeting the acceptance criteria could be prepared. On the other hand, when using a waste cathode material in the form of an oxide that has not been subjected to a roasting process, it was confirmed that calcium and silicon could not be effectively removed in the hydrolysis process, and that a complex sulfate solution meeting the acceptance criteria could not be prepared.

The terminology used in the present invention is for describing specific embodiments, and is not intended to limit the present invention. Singular expressions should be considered to include plural meanings, unless the context is clear. The terms “include” or “have” mean that there are features, numbers, steps, actions, elements, or combinations thereof described in the specification, and are not intended to exclude them. The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Accordingly, various forms of substitution, modification, and modification will be possible by those skilled in the art without departing from the technical spirit of the present invention as set forth in the claims, and it should be considered that this also belongs to the scope of the present invention. something to do.

Claims (11)

(A) reducing the anode material of the lithium secondary battery in the form of oxide through a roasting process;
(b) leaching and filtering the waste cathode material of the lithium secondary battery reduced through the roasting process with acid; And
(c) separating the metallic impurities by selectively hydrolyzing the filtrate separated in the step (b);
In the step (a), the content of calcium and silicon in the waste cathode material of the lithium secondary battery of the oxide form is more than 300mg/kg, and after the step (c), the content of calcium and silicon in the filtrate is 20mg/ A method of producing a nickel-cobalt-manganese complex sulfate solution by regenerating a waste cathode material of a lithium secondary battery of less than kg.
According to claim 1,
In step (a), the roasting process,
It is performed by adding and mixing 0.5 mol to 1.0 mol of activated carbon compared to 1 mol of lithium remaining in the oxide-type lithium secondary battery waste cathode material, and then maintaining the mixture at 600°C to 900°C for 60 to 120 minutes, Method for producing a nickel-cobalt-manganese complex sulfate solution by regenerating a lithium secondary battery waste cathode material.
According to claim 1,
In step (b), the leaching process,
Method for preparing a nickel-cobalt-manganese complex sulfate solution by regenerating a waste cathode material of a lithium secondary battery, which is performed for 180 minutes to 300 minutes at 75°C to 85°C by introducing hydrogen peroxide as a reducing agent in the presence of hydrochloric acid.
According to claim 3,
Method of preparing a nickel-cobalt-manganese complex sulfate solution by regenerating a waste cathode material of a lithium secondary battery by adjusting the concentration of the hydrogen peroxide to 10 wt% to 35 wt% and adding it in 0.1 to 5 LPM (Liter Per Minute).
According to claim 4,
A method of producing a nickel-cobalt-manganese complex sulfate solution by regenerating the waste cathode material of a lithium secondary battery, wherein the input amounts of the hydrochloric acid and the hydrogen peroxide are respectively adjusted such that the pH inside the reaction tank is 0.8 to 1.8 after the leaching process.
According to claim 1,
Step (c) comprises the step of adding a sodium carbonate aqueous solution having a content of sodium carbonate (Na ₂ CO ₃ ) of 10 wt% to 25 wt% based on the total weight of the aqueous sodium carbonate solution in a reaction tank, by regenerating the waste cathode material of a lithium secondary battery. Method for preparing a nickel-cobalt-manganese complex sulfate solution.
The method of claim 6,
The reaction tank has an internal temperature of 45°C to 75°C, a pH of 4.5 to 5.5, and a stirring speed of 180rpm to 220rpm, a method of producing a nickel-cobalt-manganese composite sulfate solution by regenerating a lithium secondary battery waste cathode material.
According to claim 1,
In the step (c), the metallic impurities include at least one selected from the group consisting of aluminum (Al), iron (Fe), magnesium (Mg), calcium (Ca), and silicon (Si), lithium secondary Method for producing a nickel-cobalt-manganese complex sulfate solution by recycling the battery waste cathode material.
According to claim 1,
(d) further comprising hydrolyzing the filtrate obtained in step (c) to separate lithium and obtaining a cake,
In the step (d), the process of adding a sodium carbonate aqueous solution having a content of sodium carbonate (Na ₂ CO ₃ ) of 10 wt% to 25 wt% based on the total weight of the aqueous sodium carbonate solution in a reaction tank is used to regenerate the waste cathode material of a lithium secondary battery. Method for preparing a nickel-cobalt-manganese complex sulfate solution.
The method of claim 9,
The reaction tank, the internal temperature is 45 ℃ to 75 ℃, pH is 6.5 to 8.5, characterized in that the stirring rate is 250rpm to 350rpm, nickel-cobalt-manganese composite sulfate solution by regenerating the lithium secondary battery waste cathode material How to manufacture.
The method of claim 9,
(e) further comprising the step of leaching and filtering the cake obtained in step (d) with acid,
In the step (e), a nickel-cobalt-manganese complex sulfate solution is regenerated by regenerating the waste cathode material of a lithium secondary battery, which is introduced into a reaction tank in the presence of sulfuric acid as a reducing agent and leached at 50°C to 85°C for 300 to 500 minutes. How to manufacture.

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