Apparatus for removing impurities from sulfate solution mixed with Nickel-Cobalt-Manganese and method for removing impurities from the solution using the same

Abstract

The present invention relates to an impurity removal device for an NCM composite, comprising: a primary purifier that removes impurities from black powder containing nickel, cobalt, and manganese to purify it into an aqueous solution containing nickel, cobalt, and manganese (primary NCM aqueous solution); a secondary purifier that purifies the NCM aqueous solution by removing impurities using an organic solvent to separate it into an aqueous solution containing nickel, cobalt, and manganese (secondary NCM aqueous solution) and a solvent containing impurities; a tertiary purifier that precipitates a solid nickel and cobalt solid from the secondary NCM aqueous solution; a diluent that dilutes the precipitated mixture of the tertiary purifier by adding water; and a solid-liquid separator that separates the diluted mixture into solid and liquid phases and then compresses the solid to produce a cake containing nickel and cobalt. Accordingly, the present invention is environmentally friendly as it enhances the potential for resource recycling by efficiently recovering useful substances, such as nickel and cobalt, from waste containing nickel, cobalt, and manganese along with various impurities through the efficient utilization of differences in the loading rate of substances into organic solvents and the precipitation reaction of hydroxides according to pH. Furthermore, the pH, concentration, and composition ratio of the purified material can be adjusted to suit desired conditions.

Description

Technology Field

[0001] The present invention relates to an impurity removal device for NCM composites, wherein the pH, concentration, composition, temperature, density, etc., can be set in various ways through a complex purification device. Background Technology

[0003] A secondary battery refers to a battery that can be recharged upon discharge and used repeatedly; it is also called a rechargeable battery or an accumulator. Since secondary batteries contain many valuable metals and resources compared to general waste electrical appliances, technologies are being developed to recover and recycle useful materials from defective products generated during the manufacturing process or from waste materials after use (see Patent Document 1).

[0004] However, despite active research, there are many difficulties in the post-processing stage due to the high difficulty of the process of removing impurities other than the useful material to be extracted from the secondary battery, and as a result, time and costs increase, leading to a problem of low actual profit. Prior art literature

[0006] Korean Patent Publication No. 10-1621312 B1 (May 16, 2016) The problem to be solved

[0007] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to manufacture substances having various compositions and concentrations by utilizing the differences in precipitation / solubility according to pH and polarity. means of solving the problem

[0009] The impurity removal device for an NCM composite according to the present invention is characterized by the following technical features: a primary purifier that removes impurities from black powder containing nickel, cobalt, and manganese to purify it into an aqueous solution (primary NCM aqueous solution) containing nickel, cobalt, and manganese; a secondary purifier that removes impurities from the NCM aqueous solution using an organic solvent to purify it by separating it into an aqueous solution (secondary NCM aqueous solution) containing nickel, cobalt, and manganese and a solvent containing impurities; a tertiary purifier that precipitates a solid nickel and cobalt solid from the secondary NCM aqueous solution; a diluent that dilutes the precipitated mixture of the tertiary purifier by adding water; and a solid-liquid separator that separates the diluted mixture into solid and liquid phases and then compresses the solid to produce a cake containing nickel and cobalt.

[0010] In addition, the secondary purifier of the present invention is characterized by the technical feature of comprising: a first tank into which the primary NCM aqueous solution, organic solvent, and sodium hydroxide (NaOH) are introduced to separate impurities; a second tank into which sulfuric acid is introduced into the organic solvent discharged from the first tank to concentrate impurities; and a third tank into which sulfuric acid is introduced into the organic solvent discharged from the second tank to purify the organic solvent.

[0011] In addition, the organic solvent of the present invention is characterized by the technical feature that P507 or P204 is mixed with kerosene.

[0012] In addition, the first tank of the present invention is characterized by the technical feature of comprising: an NCM input line for introducing the primary NCM aqueous solution into the first tank; an organic solvent input line for introducing the organic solvent into the first tank; a sodium hydroxide input line for introducing the sodium hydroxide into the first tank; a first organic solvent discharge line for discharging the organic solvent loaded with impurities inside the first tank; and a first aqueous solution discharge line for discharging the secondary NCM aqueous solution inside the first tank.

[0013] In addition, the technical feature is that the second tank comprises: a sulfuric acid input line for introducing sulfuric acid into the second tank; a second organic solvent discharge line for discharging an organic solvent loaded with impurities from the second tank; and a second aqueous solution discharge line for discharging an aqueous sulfuric acid solution in which nickel and cobalt have been recovered from the organic solvent of the second tank.

[0014] In addition, the technical feature is that the third tank comprises: a sulfuric acid injection line for introducing sulfuric acid into the third tank; a third organic solvent discharge line for discharging an organic solvent from which impurities have been removed from the third tank; and a wastewater discharge line for discharging wastewater from which impurities have been recovered from the organic solvent of the third tank.

[0015] In addition, the technical feature of the above primary purifier is that sulfuric acid, water, and hydrogen peroxide are added to the black powder to dissolve the waste, and then sodium hydroxide is added to solidify the impurities, and the solid is removed to form the above primary NCM aqueous solution.

[0016] A method for removing impurities from an NCM composite according to the present invention comprises: a step of primary purification by removing impurities from black powder containing nickel, cobalt, and manganese to obtain an aqueous solution containing nickel, cobalt, and manganese (primary NCM aqueous solution); a step of secondary purification by removing impurities from the NCM aqueous solution using an organic solvent to separate it into an aqueous solution containing nickel, cobalt, and manganese (secondary NCM aqueous solution) and a solvent containing impurities; a step of precipitating a solid nickel and cobalt solid from the secondary NCM aqueous solution; a step of diluting the precipitated mixture from the precipitation step by adding water; and a step of separating the diluted mixture into solid and liquid and then compressing the solid to produce a cake containing nickel and cobalt, wherein the secondary purification step comprises: a step of separating impurities by adding the primary NCM aqueous solution, an organic solvent, and sodium hydroxide (NaOH) to a first tank; and a step of concentrating impurities by adding the organic solvent discharged from the first tank and sulfuric acid to a second tank. and includes the step of purifying the organic solvent by introducing the organic solvent discharged from the second tank and sulfuric acid into the third tank. Effects of the invention

[0018] This invention is eco-friendly as it enhances resource recycling potential by efficiently utilizing the difference in loading rates of substances into organic solvents according to pH and the precipitation reaction of hydroxides to efficiently recover useful substances such as nickel and cobalt from waste containing nickel, cobalt, and manganese along with various impurities.

[0019] In addition, the pH, concentration, and composition ratio of the purified product can be adjusted to suit desired conditions. Brief explanation of the drawing

[0021] FIG. 1 is a schematic diagram illustrating the process of removing impurities using an impurity removal device for an NCM composite according to the present invention. FIG. 2 is a conceptual diagram illustrating a secondary purifier according to the present invention. Figure 3 is a graph showing the correlation between pH and loading rates of P204. Figure 4 is a graph showing the correlation between pH and loading rates of P507. FIG. 5 is a conceptual diagram illustrating a solid-liquid separator (filter press) according to the present invention. Specific details for implementing the invention

[0022] The present invention will be described in detail below with reference to the attached drawings. Since the present invention is susceptible to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed forms, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0023] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "composing" are intended to indicate the presence of the features, steps, components, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, steps, components, or combinations thereof.

[0024] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains.

[0025] FIG. 1 is a schematic diagram illustrating the process of removing impurities using an impurity removal device for an NCM composite according to the present invention.

[0026] The present invention relates to an impurity removal device for an NCM composite, specifically comprising: a first purifier (200) that removes impurities (110) from a black powder (100) containing nickel, cobalt, and manganese as shown in FIG. 1 to purify it into an aqueous solution (first NCM aqueous solution) containing nickel, cobalt, and manganese; a second purifier (300) that uses an organic solvent to remove impurities from the first NCM aqueous solution to separate it into an aqueous solution (second NCM aqueous solution) containing nickel, cobalt, and manganese and a solvent containing impurities; a third purifier (400) that precipitates a solid nickel and cobalt solid from the second NCM aqueous solution; a diluent (500) that dilutes the precipitation mixture of the third purifier (300) by adding water; and a solid-liquid separator (600) that separates the diluted mixture from the solid and liquid and then compresses the solid to produce a cake (140) containing nickel and cobalt.

[0027] Black powder (100) is a powder made by crushing secondary battery waste, and contains nickel (Ni), cobalt (Co), and manganese (Mn) as main components, and also contains impurities such as aluminum (Al), iron (Fe), and copper (Cu).

[0028] The primary purifier (200) is configured to primarily purify impurities from black powder (100). Specifically, the primary purifier (200) first dissolves the black powder (100) by adding sulfuric acid (H2SO4), water (H2O), and hydrogen peroxide (H2O2) to the crushed black powder (100). At this time, 60 to 90% sulfuric acid can be used, and it is preferable to adjust the pH to a level of 0.5 to 1. Then, by adding sodium hydroxide (NaOH), the pH is raised to 4.0 to 6.0 (most preferably 5.0) to solidify some of the impurities in the black powder aqueous solution. Finally, the solidified impurities (110) are removed, leaving only the primary NCM aqueous solution. The primary NCM aqueous solution is transferred to the secondary purifier (300).

[0029] FIG. 2 is a conceptual diagram illustrating a secondary purifier according to the present invention, FIG. 3 is a graph showing the correlation between the pH-loading rate of P204, and FIG. 4 is a graph showing the correlation between the pH-loading rate of P507.

[0030] The secondary purifier (300) is a device for secondary purifying a primary NCM aqueous solution from which impurities (110) have been primarily removed in the primary purifier (200), and separates / purifies necessary substances and unnecessary substances by utilizing the property of separation between the aqueous solution and the organic solvent. The secondary purifier (300) is composed of a device including a mixer such as a mixer-settler and a precipitator, and can separate impurities and useful substances by utilizing the phase difference between polar and non-polar solvents.

[0031] The secondary purifier (300) is basically composed of a single mixer-settler and can perform secondary purification of the primary NCM aqueous solution, and furthermore, can perform additional extraction / purification from the separated material after purification. In the latter case, the secondary purifier (300) includes a first tank (310) into which the primary NCM aqueous solution, organic solvent, and sodium hydroxide (NaOH) are introduced to separate impurities; a second tank (320) into which sulfuric acid is introduced into the organic solvent discharged from the first tank (310) to concentrate impurities; and a third tank (330) into which sulfuric acid is introduced into the organic solvent discharged from the second tank (320) to purify the organic solvent.

[0032] The first tank (310) includes an NCM input line (311) for introducing the first NCM aqueous solution into the first tank (310); an organic solvent input line (312) for introducing the organic solvent into the first tank (310); a sodium hydroxide input line (313) for introducing the sodium hydroxide into the first tank (310); a first organic solvent discharge line (314) for discharging the organic solvent loaded with impurities inside the first tank (310); and a first aqueous solution discharge line (316) for discharging the second NCM aqueous solution, which is an aqueous solution inside the first tank (310).

[0033] In the first tank (310), the primary NCM aqueous solution is introduced through the NCM input line (311), and then the organic solvent and sodium hydroxide are introduced through the organic solvent input line (312) and the sodium hydroxide input line (313). At this time, the organic solvent refers to kerosene used as a solvent and mixed with P507 or P204. As shown in FIG. 4, the type and amount of material loaded into the solvent of P507 varies depending on the pH, and the same applies to P204 (see FIG. 3). For example, in the case of P204, it can be seen that most of the iron (Fe), zinc (Zn), and calcium (Ca) are loaded at pH 2.0. The organic solvent loaded with impurities is discharged through the first organic solvent discharge line (314). Subsequently, when additional P204 solvent is added and sodium hydroxide is also added, causing the pH to increase, the loading rate of aluminum (Al), copper (Cu), and manganese (Mn) ions in the organic solvent increases rapidly. However, it can be seen that when the pH exceeds 2, the loading rate of cobalt (Co) also increases; in this case, cobalt can be removed from the organic solvent with sulfuric acid by lowering the pH by adding 5% or less of sulfuric acid in the cleaning tank (315). In the case of P507, if used after the cobalt (Co) has been removed, impurities other than nickel (Ni) can be efficiently removed (at a pH level of about 5.0).

[0034] The aqueous solution, i.e., the secondary NCM aqueous solution, from which impurities have been removed through an organic solvent in the first tank (310), can be discharged through the first aqueous solution discharge line (316) and stored in the storage tank (317). The aqueous solution is then transferred to the third purifier (400).

[0035] The second tank (320) is a device for additionally separating impurities and useful substances from an aqueous solution or solvent remaining after the primary recovery of useful substances such as nickel and cobalt in the first tank (310). As shown in FIG. 2, the second tank (320) includes a sulfuric acid input line (322) for introducing sulfuric acid into the second tank (320); a second organic solvent discharge line (324) for discharging an organic solvent loaded with impurities from the second tank (320); and a second aqueous solution discharge line (326) for discharging an aqueous sulfuric acid solution in which nickel and cobalt have been recovered from the organic solvent of the second tank (320).

[0036] The sulfuric acid introduced from the second tank (320) can be used to extract useful substances (nickel, cobalt, etc.) contained in the organic solvent into an aqueous solution using 1 to 5% sulfuric acid. The aqueous solution from which nickel and cobalt have been recovered from the second tank (320) is discharged through the second aqueous solution discharge line (326) and can be sent to the third purifier (400). The organic solvent containing impurities is then transferred to the third tank (330) through the second organic solvent discharge line (324).

[0037] The third tank (330) is a device for separating and disposing of organic solvent, from which impurities have been finally purified within the second purifier (300), and wastewater containing a large amount of impurities. Specifically, the third tank (330) includes a sulfuric acid injection line (332) for introducing sulfuric acid into the third tank (330); a third organic solvent discharge line (334) for discharging organic solvent from which impurities have been removed from the third tank (330); and a wastewater discharge line (336) for discharging wastewater (120) from which impurities have been recovered from the organic solvent of the third tank (330).

[0038] 20 to 40% sulfuric acid is injected into the sulfuric acid injection line (332) of the third tank (330) to recover most of the impurities contained in the organic solvent into an aqueous solution, and this wastewater (120) is discharged through the wastewater discharge line (336). On the other hand, the organic solvent of the third tank (330) can be reused as impurities are removed.

[0039] The third purifier (400) introduces sodium hydroxide into the second NCM aqueous solution discharged from the second purifier (300) to raise the pH to a level of 10 to 12, thereby precipitating (solidifying) nickel and cobalt, and the sodium remains in an aqueous solution state.

[0040] The diluent (500) dilutes the solid-liquid mixture discharged from the third purifier (400) by adding an excess amount of water.

[0041] FIG. 3 is a conceptual diagram illustrating a solid-liquid separator (filter press) according to the present invention.

[0042] The solid-liquid separator (600) separates the solid nickel and cobalt cake (140) and the liquid from the mixture diluted in the diluter (500) using a filter press, thereby treating the liquid as wastewater (130). Finally, nickel and cobalt cake (140) is produced from the solid-liquid separator (600).

[0043] As an additional step, the solid cake (140) can be redissolved using sulfuric acid to convert it into a liquid form, and then adjusted according to requirements, such as various pH, concentration, and composition ratios. For example, even if the ratio of nickel, cobalt, and manganese is required in various ways, such as 9:0.5:0.5, 8:1:1, or 6:2:2, recovery can be performed accordingly. In addition, conditions for strictly removing only specific impurities are also possible.

[0044] The method for removing impurities from an NCM composite according to the present invention can efficiently remove impurities such as aluminum, iron, and copper contained in the NCM composite by using an impurity removal device for an NCM composite as described above. Explanation of the symbols

[0046] 100: Black powder 110: Wastewater 120: Wastewater 130: Wastewater 140: Cake 200: Primary purifier 300: Secondary purifier 310: 1st Tank 311: NCM input line 312: Organic solvent input line 313: Sodium hydroxide injection line 314: 1st Organic Solvent Discharge Line 315: Cleaning tank 316: First aqueous solution discharge line 317: Storage tank 320: 2nd Tank 322: Sulfuric acid injection line 324: 2nd Organic Solvent Discharge Line 326: Second aqueous solution discharge line 330: 3rd Tank 332: Sulfuric acid injection line 334: 3rd Organic Solvent Discharge Line 336: Wastewater discharge line 400: 3rd purifier 500: Diluent 600: High-liquid separator

Claims

Claim 1 A primary purifier that removes impurities from black powder containing nickel, cobalt, and manganese to purify it into an aqueous solution containing nickel, cobalt, and manganese (primary NCM aqueous solution); a secondary purifier that purifies by removing impurities from the NCM aqueous solution using an organic solvent and sodium hydroxide (NaOH) to separate it into an aqueous solution containing nickel, cobalt, and manganese (secondary NCM aqueous solution) and a solvent containing impurities; a tertiary purifier that precipitates a solid nickel and cobalt solid from the secondary NCM aqueous solution; and a diluent that dilutes the precipitated mixture of the tertiary purifier by adding water. An impurity removal device for an NCM composite, comprising a solid-liquid separator that separates the diluted mixture and then compresses the solid to produce a cake containing nickel and cobalt, wherein the secondary purifier comprises: a first tank into which the primary NCM aqueous solution, an organic solvent, and sodium hydroxide (NaOH) are introduced to separate impurities; a second tank into which sulfuric acid is introduced into the organic solvent discharged from the first tank to concentrate impurities; and a third tank into which sulfuric acid is introduced into the organic solvent discharged from the second tank to purify the organic solvent. Claim 2 delete Claim 3 An impurity removal device for an NCM complex according to claim 1, wherein the organic solvent is kerosene mixed with P507 or P204. Claim 4 An impurity removal device for an NCM composite according to claim 1, wherein the first tank comprises: an NCM input line for introducing the primary NCM aqueous solution into the first tank; an organic solvent input line for introducing the organic solvent into the first tank; a sodium hydroxide input line for introducing the sodium hydroxide into the first tank; a first organic solvent discharge line for discharging the organic solvent loaded with impurities inside the first tank; and a first aqueous solution discharge line for discharging the secondary NCM aqueous solution inside the first tank. Claim 5 In claim 4, the impurity removal device for an NCM composite comprises: a sulfuric acid injection line for introducing sulfuric acid into the second tank; a second organic solvent discharge line for discharging an organic solvent loaded with impurities from the second tank; and a second aqueous solution discharge line for discharging an aqueous sulfuric acid solution in which nickel and cobalt have been recovered from the organic solvent of the second tank. Claim 6 An impurity removal device for an NCM composite according to claim 1, wherein the third tank comprises: a sulfuric acid injection line for introducing sulfuric acid into the third tank; a third organic solvent discharge line for discharging an organic solvent from which impurities have been removed from the third tank; and a wastewater discharge line for discharging wastewater from which impurities have been recovered from the organic solvent of the third tank. Claim 7 An impurity removal device for an NCM composite according to claim 1, wherein the primary purifier dissolves the black powder by administering sulfuric acid, water, and hydrogen peroxide to the black powder, then adds sodium hydroxide to solidify the impurities, and then removes the solids to form the primary NCM aqueous solution. Claim 8 A step of primary purification by removing impurities from black powder containing nickel, cobalt, and manganese to obtain an aqueous solution containing nickel, cobalt, and manganese (primary NCM aqueous solution); a step of secondary purification by removing impurities from the NCM aqueous solution using an organic solvent to separate it into an aqueous solution containing nickel, cobalt, and manganese (secondary NCM aqueous solution) and a solvent containing impurities; a step of precipitating a solid nickel and cobalt solid form from the secondary NCM aqueous solution; a step of diluting the precipitated mixture from the precipitation step by adding water; and a step of separating the diluted mixture into solid and liquid and then compressing the solid to produce a cake containing nickel and cobalt, wherein the secondary purification step comprises: a step of separating impurities by adding the primary NCM aqueous solution, an organic solvent, and sodium hydroxide (NaOH) to a first tank; and a step of concentrating impurities by adding the organic solvent discharged from the first tank and sulfuric acid to a second tank. A method for removing impurities from an NCM complex, comprising the step of purifying the organic solvent by introducing the organic solvent discharged from the second tank and sulfuric acid into the third tank.

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