JP4388091B2 - Noble metal recovery method from Co, Ni, Mn containing battery - Google Patents

Description

The present invention relates to a method for recovering valuable metals from a Co, Ni, Mn-containing lithium battery case. Co, Ni, Mn-containing lithium battery is a slurry material consisting of a ternary Li metal salt and a solvent such as carbon, N-methyl-2-pyrrolidone, polyvinyl alcohol, etc., and is generated in the lithium secondary battery manufacturing process. It is a trap. The treatment of lithium metal oxide containing valuable metals in these battery cells is important from the viewpoint of valuable metal recovery.

  Patent Document 1: Japanese Patent Application Laid-Open No. 6-251805 discloses that a lithium secondary battery was not yet developed in 1993 at the time of filing, but was prepared for recycling of a lithium secondary battery prior to development. is there. In this method, a used lithium battery is cut with a water jet, and a solid separated from the liquid by filtration is sorted into a separator, a current collector, and a positive electrode material. They explain that they can be melted or crushed and reused depending on the material. In addition, various metals such as Ni, Co, Ti, Fe, V, Mn, Mo.Cr, W are listed as the metal of the metal oxide used as the positive electrode material, but all of these metals are used. Rather than being Co, the most common metal at present is Co.

  Patent Document 2: Japanese Patent Laid-Open No. 2006-331707 proposes a lithium battery recycling method consisting of many stages, and mechanically separates the wound body, the positive electrode, the negative electrode, and the separator before and after the recovery of the positive electrode material. Then, the positive electrode is immersed in an aqueous nitric acid solution to separate the positive electrode base material (aluminum) and the positive electrode active material, and the positive electrode active material is immersed in a hydrochloric acid solution to dissolve, and the solution is filtered to remove metal ions such as Li and Ni. A mixed solution is obtained. Next, each metal is recovered from the mixed solution by using techniques such as ion exchange, electrolysis, and precipitation separation.

  Patent Document 3: Japanese Patent No. 3450684 is an application in 1997 in which a lithium secondary battery was to be mounted on various electronic devices. From a positive electrode active material of a used lithium battery, Mo, Co, Ni , Proposes a method for recovering Sn. Specifically, a used lithium battery is roasted together with an iron case without being disassembled, pulverized into the roasted product; primary magnetic selection; and nonmagnetic material is subjected to secondary magnetic selection.

  Recently, technological development has been carried out in which a lithium acid metal salt containing almost equal amounts of Co, Ni and Mn is used as a positive electrode active material. For example, Patent Document 4: Japanese Unexamined Patent Application Publication No. 2007-48692 discloses that manganese dioxide, cobalt oxide, nickel oxide, and lithium carbonate have a Ni: Mn: Co ratio of 1: 1: 1, and Li: (Ni, Mn, Co ) Weigh so that the ratio is 1.06: 1, mix these compounds with the polyvinyl alcohol solution, and then granulate, dry and calcine. This calcined ternary metal Li double oxide is mixed with a binder and a solvent to prepare a slurry-like positive electrode active material.

The positive electrode active material of the nickel-hydride battery is nickel oxyhydroxide (NiOOH), not the lithium acid metal that is the positive electrode active material of the lithium battery. Regarding such a method for recovering a metal from a nickel-hydride battery, Japanese Patent Application Laid-Open No. 10-510878 proposes the following method. That is, (1) crushing a waste battery with a shredder; (2) separating Fe and Ni by magnetically selecting the obtained scrap; (3) dissolving a nonmagnetic material with sulfuric acid; (4) adjusting pH (5) Zn, Cd, Mn, and Al are extracted by extracting the filtrate from which Fe has been separated by filtration with an organic solvent.
JP-A-6-251805 JP 2006-331707 A Japanese Patent No. 3450684 JP 2007-48692 A Japanese National Patent Publication No. 10-510878 "Resources and Materials", 1997,12, Vol.113, Special issue on recycling, page 941 Lecture, Modern Metallurgy, Refinement 2, Nonferrous Metal Smelting, July 10, 1982, Japan Institute of Metals, pp. 240-241

Battery recycling includes a method of recycling the battery as it is as in Patent Documents 3 and 5, and a method of disassembling and collecting the battery into respective constituent members or materials as proposed in Patent Documents 1 and 2. The present invention is a method for recycling a slurry-like battery case generated from a battery manufacturing process, and does not belong to any of these methods.
An object of the present invention is to provide a method for recovering valuable metals from a ternary Li metal salt contained in a battery case of a lithium battery.

The present invention relates to a lithium acid metal salt, except that Co, Ni and Mn ternary metal salts
A lithium acid, and each content of Co, Ni and Mn is 10 to 12% by mass-
(Hereinafter referred to as “ternary Li metal salt”), carbon, and solvent.
The discharged slurry-like lithium battery cell is stirred and leached at room temperature with a hydrochloric acid solution having a concentration of 250 g / l or more , or heated and leached with a sulfuric acid solution having a concentration of 200 g / l or more, and Mn, Co and
100% Ni was leached, and for the obtained leachate, Mn and Co were respectively extracted with solvent, and Co, Ni, Mn
The present invention proposes a method for recovering valuable metals from Co, Ni, Mn-containing battery tanks, characterized in that a solution containing each metal is generated and the metals are recovered from these solutions.

  The battery soot is a slurry-like material composed of a ternary Li metal salt and a solvent such as carbon, N-methyl-2-pyrrolidone, polyvinyl alcohol, etc., and should be generated during the lithium secondary battery manufacturing process. The metal composition is 10-12 mass% Co, 10-12 mass% Ni, 10-12 mass% Mn.

The inventors of the present invention have leached a battery of ternary Li metal salt under the following conditions, and as a result, have confirmed that sulfuric acid and hydrochloric acid are effective for leaching all of the ternary metal.
(B) Battery jar: as described in paragraph 0005; 200 g.
(B) Leachate: various acids with concentrations shown in Table 1; capacity 2000 mL.
(C) Leaching time: 4h-8h
(D) Temperature: Heated to room temperature or 70-80 ° C.
(E) Stirring: Yes.
The test results are shown in Table 1.

Regarding the leaching of ternary Li metal salts, the following can be seen.
(1) If stirring and leaching for 8 hours while heating at 70 to 80 ° C, 100% leaching of Co, Ni and Mn is possible even with 200g / l sulfuric acid aqueous solution. Leaching is possible even at temperatures above 80 ° C, but evaporative sulfuric acid purification equipment is required. Furthermore, in the case of 300 g / l sulfuric acid aqueous solution, a similar leaching rate can be achieved by performing sulfuric acid leaching for 8 hours at 65 to 75 ° C.
(2) In the leaching only with stirring, the leaching rate is 100% for both Co, Ni and Mn if the hydrochloric acid solution has a concentration of 250 g / l or more.

As described above, when sulfuric acid aqueous solution with a concentration of 200 g / l or more is heated and leached,
100% leaching rate can be achieved.
Next, for leaching only with stirring, a leaching rate of 100% can be achieved with a hydrochloric acid aqueous solution having a concentration of 250 g / l or more.
In the present invention, the leaching rate is set to 100% because it is defined in consideration of an error in weighing, and it is ± 1% when the battery case is normally recycled 100 tons or more in monthly production. The leachate generated as a result of leaching contains ternary metal ions, and the residue is mainly composed of carbon in an organic or inorganic state. Such carbon is sparingly soluble in sulfuric acid and hydrochloric acid and remains as a solid, but since carbon and the like are not worth collecting, the residue after leaching is discarded.
Stirring can be performed by any means such as a rotating blade so that the slurry-like battery can be uniformly dispersed in the leachate.

  In recovering Co, Ni, and Mn contained in the liquid after leaching, Ni is separated by solvent extraction of the two types of metals, Mn and Co. As an extractant for extracting these solvents, for example, Non-Patent Document 1: Resources and Materials, 1997, 12, Vol. 113, “Recycling Special Feature”, page 941, page 1, known acidic extractant Can be used.

  It is preferable to use D2EHPA manufactured by LANXESS as the Mn extractant and PC-88A manufactured by Daihachi Chemical Co., Ltd. as the Co extractant. D2EHPA is di-2-ethylhexyl phosphoric acid and is a Mn extractant known in Non-Patent Document 1. PC-88A is a 2-ethylhexyl 2-ethylhexylphosphonate system, and its information is available at http: //www/daihachi-chem.co.jp/sehin/pdf/kinz.pdf.

The method for recovering the metal from the solution after extraction can be carried out as described below, or can be sold as an auxiliary material in a known wet refining process.
About Co: Electrolytic extraction of Co chloride.
About Mn: Electrolytic extraction of Mn sulfate
About Ni: Ni electrolysis method by chlorine leaching.

  As another method for recovering the metal, a method can be employed in which the metal salt is precipitated by neutralizing a sulfuric acid acidic solution, which is a back-extracted solution after solvent extraction, and recovered as a solid content by filtration. . Subsequently, the metal salt can be sold to a metal refining company as a metal raw material. Alternatively, when the concentration of the metal salt is concentrated several times the concentration in the solution after solvent extraction and then recovered by electrowinning, it is possible to recycle consistently from the recovery of the battery to the metal regeneration. Electrolytic extraction of Ni, Co, and Mn is, for example, Non-Patent Document 2: Lecture / Modern Metallurgy, Refining Edition 2, Nonferrous Metal Smelting, published on July 10, 1982, Japan Institute of Metals, pp. 240-241 It can be performed under the conditions described.

Next, a method for solvent extraction of Mn and Co with DE2HPA and PC-88A, respectively, will be specifically described with reference to FIG.
Extraction of Mn
DE2HPA kerosene (kerosene) mixture (solvent A) and Co-Ni-Mn solution (ie, leached solution, see Fig. 1), sight flow and mixing in a separatory tank with a stirrer for solvent extraction. Add caustic soda to adjust pH to 2-3.
Thereafter, extraction with a solvent is further performed, so that only Co—Ni remains in the solution. In the opposite direction to the solution, the solvent A becomes Extract 3, Extract 2, and Extract 1 (countercurrent multistage extraction), the Co concentration gradually decreases, and then Co is washed with 10 g / l H ₂ SO _4. (Wash 1).
Subsequently, back extraction is performed with a 50 g / l sulfuric acid aqueous solution to concentrate Mn in the sulfuric acid aqueous solution (“Mn solution”). Back extraction is performed in two stages, and solvent A is reused in extraction 3. Caustic soda is added to the Mn solution for neutralization, and the neutralized liquid and precipitate are filtered to recover Mn as Mn (OH) ₂ . The washing solution is added to the Co-Ni-Mn solution before extraction.

It differs from Mn extraction in that the extractant for Co is PC-88A, and the other processing flow is the same as in FIG. Accordingly, the “Co-Ni-Mn solution”, “Mn solution”, and “Co-Ni solution” in FIG. 1 replace “Co-Ni solution”, “Co solution”, and “Ni solution”, respectively.

Table 2 shows the general ranges of the Co, Ni, and Mn concentrations obtained by the solvent extraction described above and the concentrations in the examples. Metals can be recovered as Mn (OH) ₂ , Co (OH) ₂ , and NiCO ₃ by neutralization, respectively.

From the above, preferred embodiments of the present invention are as follows.
(1) A method of extracting Mn and Co with an acidic solvent.
(2) A method of precipitating Mn, Co, Ni by adjusting the pH of the solution after back extraction, and separating the metal as a solid content by filtration.
(3) The method according to item (2), wherein the solid metal is redissolved in the electrolytic solution and electrolytically collected.

(1) Since the ternary Li metal salt cathode active material can be recycled in a slurry state, no energy is required to solidify the waste lithium battery case. further,
Since the ternary metallic Li salt in the slurry is in the form of fine particles, the contact area with the leachate is large and the leaching efficiency is high.
(2) All of Co, Ni and Mn can be leached. On the other hand, carbon other than this becomes a residue and is separated from the above three kinds of metals. Since the solvent extraction is performed only twice, the process does not become long.
(3) Since diluted sulfuric acid or diluted hydrochloric acid is used, the burden on the environment is small.
(4) Li dissolves in the leachate, but it can be separated from the metal by solid-liquid separation (it remains in the liquid after Ni is precipitated from the Ni solution). Li is present in the Ni solution after separation of Mn and Co in the solvent extraction, but after precipitation of Ni, Li remains in the filtrate and is separated. Alternatively, when the Ni solution is concentrated for the electrolytic solution, solvent extraction is performed.
Remains in the solution without extraction and is separated. In any case, Li is separated.
(5) Using a Co-based compound as a positive electrode active material of a battery of an electronic device,
It is quite possible that both new ternary Li metal salts will continue to be on the market. In this case, the lithium battery case includes a Co battery. Thus, even if the number of types of batteries increases, it is possible to recover valuable metals by performing acid leaching according to the present invention and then performing solvent extraction.

Ternary Li metal salt- containing slurry (Co 11 %, Ni 11%, Mn 11%, simply below
Leaching and solvent extraction were performed per 100 kg of “slurry” . In the test described below, the extraction time was 10 minutes with stirring, the back extraction time was 10 minutes with stirring, and the washing was performed with 10 minutes of stirring.
(1) Leaching
The slurry was put into 1000 L of 300 g / l sulfuric acid aqueous solution and stirred for 4 hours while heating at 70-80 ° C.,
Subsequent filtration left 10 kg of residue in the dried state. The metal concentration in the 1000 L filtrate was as shown in the following table, and 100% leaching was achieved.

(2) Mn extraction The filtrate was neutralized with a 25% NaOH solution, and Mn was subjected to solvent extraction. The solution after neutralization was 1290L. The solvent extractant was 1290 L of LANXESS D2EHPA kerosene solution, which was stirred with the neutralized solution and adjusted to pH = 2.5 with a 25% NaOH solution (O / A ratio = 1/1). As a result of solvent extraction, 1290 L of Mn extract and 1340 L of Co—Ni solution were obtained. The Mn extract (containing a little Co) is washed with 10 g / l H ₂ SO ₄ , followed by back extraction with a 50 g / l sulfuric acid aqueous solution to concentrate Mn in the sulfuric acid aqueous solution (Mn solution). Co-Ni solution 1290L (metal concentration is shown in Table 4) and Mn solution 250L (metal concentration is shown in Table 5) were obtained.

The Co and Ni solutions shown in Table 4 were subjected to solvent extraction of Co. The solvent extractant was 1290 L of Daisuke Chemical Co., Ltd. PC-88A kerosene solution, which was stirred with the neutralized solution and adjusted to pH = 4.2 with 25% NaOH solution (O / A ratio = 1/1 / 1). As a result of solvent extraction, Co extract 1340L and Ni solution 1390L were obtained. The Co extract (containing a little Ni) is washed with 10 g / l H ₂ SO ₄ , followed by back extraction with a 50 g / l sulfuric acid aqueous solution to concentrate Co in the sulfuric acid aqueous solution (Co solution). Ni solution 1390L (metal concentration is shown in Table 6) and Co solution 250L (metal concentration is shown in Table 7) were obtained.

    As shown above, Mn, Co, and Ni could all be separated. Although an example of sulfuric acid leaching has been described, since the entire amount of metal can be leached even by hydrochloric acid leaching, subsequent solvent extraction has the same result.

Previously, there was no recycling method for battery cages using ternary Li metal salt as the positive electrode active material, so they were stored in warehouses. However, if the battery cages were leached with sulfuric acid or hydrochloric acid according to the method of the present invention, valuable metals were recovered. Is possible. In addition, since the solvent extraction method is employed in the method of the present invention, for example, even if a Co-based positive electrode active material is mixed in the battery case, valuable metals can be recovered without problems, so that the recycling business can be easily developed. is there.

It is a flowchart which shows the solvent extraction process of Mn.

Claims (3)

Lithium acid metal salt-except for Co, Ni and Mn ternary metal salts and lithium
An acid, and each content of Co, Ni and Mn is 10 to 12% by mass; and carbon;
A slurry-like lithium battery tank made of a solvent and discharged in the lithium battery manufacturing process ,
Stir and leach at room temperature with a hydrochloric acid solution with a concentration of 250 g / l or more , or heat and stir and leach with a sulfuric acid solution with a concentration of 200 g / l or more to leach 100% of Mn, Co and Ni. It was per leachate,
Mn and Co are each solvent-extracted to produce a solution containing each of Co, Ni, and Mn metals,
Valuable money from Co, Ni, Mn-containing battery cages characterized by recovering the metal from these solutions
How to recover the genus . Co, Ni, Mn Co, according to claim 1, characterized in that Co, Ni, Mn is precipitated by adjusting the pH of the solution containing each metal of Co, Ni, Mn, and recovered as a solid by filtration. A method for recovering valuable metals from Ni, Mn-containing batteries. The solid matter is redissolved in an electrolytic solution and collected by electrolysis.
A method for recovering valuable metals from a Co, Ni, Mn-containing battery container according to claim 2 .

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