Method for recovering manganese contained in waste batteries and recovery equipment

Abstract

A high-purity manganese-containing solution is recovered from waste batteries with a high yield. As a method for recovering manganese contained in waste batteries, the following steps are performed in this order: a sorting process of waste batteries; a crushing and sieving process to obtain a separated body from said waste batteries; an acid and oxidizing agent treatment process of said separated body; a first solid-liquid separation process to separate a first leaching residue; an acid and reducing agent treatment process to obtain a second leaching solution from said first leaching residue; a second solid-liquid separation process to separate the second leaching solution; and a manganese extraction process to obtain a manganese ion-containing solution from said second leaching solution; wherein the manganese extraction process includes a predetermined zinc removal process and an iron removal process in no particular order.

Description

Technology Field

[0001] The present invention relates to a method for recovering valuable metals from waste batteries and a recovery facility. In particular, the present invention relates to a method for recovering manganese contained in waste batteries and a recovery facility, wherein, as a valuable metal, manganese (Mn), which is a major valuable component of waste batteries, is separated after treating waste manganese batteries and / or alkaline manganese batteries with an acid and an oxidizing agent, and recovered as high-purity manganese suitable for use in various batteries. Background Technology

[0002] Recently, due to the depletion of metal resources and rising trading prices, it has become necessary to actively recover valuable metals from low-grade raw ore, concentrates, by-products from steel mills, and industrial waste. For example, manganese, one of the valuable metals, is considered an essential metal across various sectors of industry, and there are concerns that future demand will exceed reserves. In particular, steel mills have traditionally consumed large quantities of manganese as a raw material for steelmaking, making the securing of manganese sources a critical issue in the steel industry. Furthermore, with the recent increase in manganese consumption for secondary batteries, including lithium-ion batteries, securing manganese sources has become a serious problem in this secondary battery sector as well.

[0003] Meanwhile, in Japan, a massive amount of batteries are produced and consumed, and are disposed of and destroyed as industrial waste. Some of the batteries (waste batteries) being destroyed as industrial waste contain a high manganese content. For example, manganese batteries and alkaline manganese batteries, which are representative primary batteries, use manganese dioxide (MnO2) as the positive electrode material.

[0004] Therefore, if manganese components can be recovered from these spent batteries with high purity, it is promising in terms of securing a stable source of manganese.

[0005] However, spent batteries contain metallic components such as zinc (Zn) and iron (Fe) in addition to manganese. The former is mainly found in the negative electrode material and electrolyte, while the latter is primarily contained in the battery casing. Therefore, when recovering manganese from spent batteries, it is important to separate metallic components such as zinc and iron from the manganese as much as possible.

[0006] The inventors examined a technology for separating zinc and iron from waste batteries and recovering manganese with high purity, and proposed Patent Document 1, “Method for recovering manganese from waste batteries and recovery facility.” The proposal in Patent Document 1 is a method for obtaining high-purity manganese by performing acid leaching by mixing an acid solution and a reducing agent on a powder obtained by crushing and sieving waste batteries, as shown in FIG. 1, and then precipitating and removing zinc and iron. Prior art literature

[0007] International Publication No. 2021 / 075135 The problem to be solved

[0008] However, the method described in Patent Document 1 had room for further consideration regarding the yield of manganese. Specifically, the powder obtained by crushing and sieving waste batteries contains a large amount of zinc after manganese, and a large amount of zinc is transferred into the leaching solution along with manganese through acid leaching treatment. Subsequently, when the zinc in this leaching solution is precipitated and removed using a sulfide agent, some manganese is mixed in and precipitated (co-precipitated) when the zinc precipitates as a sulfide, thereby reducing the yield of manganese. Furthermore, since sulfide agents are more expensive than general acids or alkalis, there was also a problem in terms of cost when precipitating and removing a large amount of zinc using a sulfide agent.

[0009] The present invention, made in consideration of the above-mentioned problems, aims to provide a method for recovering manganese from waste batteries and a recovery facility capable of recovering manganese contained in waste batteries with high yield as a high-purity manganese-containing solution with very low mixing of zinc and iron.

[0010] In addition, the term "high-purity manganese-containing solution" as used herein refers to a manganese-containing solution in which zinc and iron as impurities in the solution are both below the analytical limit, for example, less than 0.1 mg / L, when analyzed using an analytical method specified in commercial JIS standards. means of solving the problem

[0011] When manganese batteries and / or alkaline manganese batteries are selected from waste batteries, crushed, and sieved, the materials constituting the batteries are separated into solids on the sieve and granular materials below the sieve. Among the materials constituting the batteries, mainly iron-clad packaging materials, zinc cans, brass rods, paper materials, plastics, etc., become foil-like or flake-like solids after crushing and are separated on the sieve. Meanwhile, manganese dioxide (MnO2), carbon (C), zinc chloride (ZnCl2), ammonium chloride (NH4Cl), potassium hydroxide (KOH), or additionally manganese oxyhydroxide (MnO(OH)), zinc hydroxide (Zn(OH)2), manganese hydroxide (Mn(OH)2), zinc oxide (ZnO), etc. generated by discharge, become granular materials and are separated below the sieve. In addition, usually, trace amounts of iron are inevitably mixed into these granular materials.

[0012] The inventors carefully examined a method to selectively remove only zinc in advance by promoting the leaching of zinc while suppressing the dissolution of manganese, in order to increase the yield of manganese. As a result, they recognized that by adding an oxidizing agent when an acid solution is applied to a powder, it is possible to preferentially leach and remove zinc into the leaching solution while suppressing the amount of manganese dissolution (acid-oxidizing agent treatment process).

[0013] Furthermore, the inventors recognized that by applying an acid and a reducing agent to a powder (first leaching residue) in which only the zinc content has been significantly reduced by an acid and oxidizing agent treatment process, and obtaining a leaching solution (second leaching solution) in which manganese, iron, and remaining zinc are further leached, and then selectively precipitating and separating the remaining zinc and iron components from the second leaching solution in a predetermined order, a high-purity manganese solution can be obtained simply and with a high yield, regardless of the order of the precipitation and separation process.

[0014] As a more specific method, Step A, the inventors have confirmed that by performing a sulfide precipitation treatment process in which zinc ions still remaining in the second leaching solution are selectively precipitated as sulfides (zinc-containing sulfides) by reacting a sulfide, such as sodium hydrosulfide (NaHS), with the second leaching solution, and a zinc separation process in which the obtained zinc-containing precipitates are separated, a zinc component can be further removed from the second leaching solution (zinc removal process in Step A), and the zinc ion concentration in the solution remaining after the zinc removal process (third solution) can be easily reduced to less than 0.1 mg / L, which is the analytical limit; and subsequently, by performing an additional oxidation treatment process on the third solution and further separating iron ions as iron-containing precipitates (iron separation process), a high-purity manganese solution can be obtained simply and with a high yield as the solution remaining after the separation of iron components (fourth solution) (iron removal process in Step A).

[0015] In addition, as a specific alternative method, method B, the inventors have confirmed that by oxidizing the second leaching solution, for example, with air, the iron ions contained in the second leaching solution are selectively precipitated, for example, as a hydroxide, thereby preferentially separating only the iron component from the second leaching solution, and the iron ion concentration in the solution remaining after the separation of the iron component (third solution) can be significantly reduced (iron removal process in method B); subsequently, by performing a sulfide precipitation treatment in which a sulfide such as sodium hydrosulfide is applied to the third solution and the remaining zinc ions are further separated as a zinc-containing precipitate, a high-purity manganese solution can be obtained simply and with a high yield as the fourth solution remaining after separation (zinc removal process in method B).

[0016] The inventors will explain the results of experiments (A) and (B) performed according to each of the above steps A and B.

[0017] Experiment (A)

[0018] Manganese batteries and alkaline manganese batteries were separated from waste batteries (separation process), and a crushing and sieving process was additionally performed to obtain a granular body.

[0019] An acid solution and an oxidizing agent were mixed with the obtained powder under the following conditions, and an acid-oxidizing agent treatment process was performed.

[0020] Acid solution: Sulfuric acid (H2SO4) (Volume: 100 mL, Concentration: 1.0 mol / L (approx. 8.7 mass%))

[0021] Oxidizing agent: Sodium hypochlorite (NaClO) aqueous solution

[0022] (Effective chlorine (Cl2) 5.0% or more, amount: 50 mass% relative to acid solution)

[0023] Processing time: 1 hour of stirring

[0024] Solid-to-liquid ratio of powder and acid solution: 100g / L

[0025] Next, the obtained mixture was filtered using a filter paper with a pore size of 1 μm to separate the first leaching solution and the first leaching residue from solid to liquid (first solid-liquid separation process). The concentrations of manganese, zinc, and iron in the separated first leaching residue were quantified by ICP emission spectroscopy. The results of the component analysis before and after the acid and oxidizing agent treatment process are shown in Table 1. After the acid and oxidizing agent treatment process, the zinc concentration in the separated first leaching residue decreased significantly to 3.53 mass%. On the other hand, the manganese concentration in the first leaching residue increased significantly to 58.59 mass% because the addition of an oxidizing agent effectively suppressed the dissolution of the manganese component into the first leaching solution. As a result, the yield of manganese from the powder to the first leaching residue was 99.99%.

[0026]

[0027] In Table 1, it can be seen that in the first leaching residue after the acid-oxidizing agent treatment process, most of the zinc is removed while the manganese contained in the powder is well preserved, but some zinc still remains. Therefore, as described below, if an acid-reducing agent treatment is performed on the first leaching residue separated after the acid-oxidizing agent treatment process by applying an acid solution and a reducing agent to further leach out the remaining zinc components, and then a sulfide precipitation treatment is performed on the obtained second leaching solution, the remaining zinc components can be selectively and sufficiently precipitated as described above. As a result, the removal of zinc components can be performed reliably, easily, and at a low cost while increasing the yield of manganese.

[0028] After the acid and oxidizing agent treatment process, an acid and reducing agent treatment process was performed on the first leaching residue separated, in which an acid solution and a reducing agent were applied. Subsequently, a second solid-liquid separation process was performed by filtering the obtained mixture through a filter paper with a pore size of 1 μm to obtain a second leaching solution and a second leaching residue. In addition, the acid solution used in the acid and reducing agent treatment process was sulfuric acid (concentration: 1.0 mol / L (approx. 8.7 mass%)), the reducing agent was 30% hydrogen peroxide (H2O2) water, and the mixture was stirred for a treatment time of 1 hour. Through this acid and reducing agent treatment process and the second solid-liquid separation process, a second leaching solution containing at least manganese ions, iron ions, and residual zinc ions was obtained.

[0029] The manganese, zinc, and iron concentrations in the obtained second leaching solution were quantitatively analyzed using ICP emission analysis, and the manganese concentration was 31826 mg / L, the zinc concentration was 1919 mg / L, and the iron concentration was 163 mg / L.

[0030] Next, a sulfide precipitation treatment process was carried out in which sodium hydrosulfide was added as a sulfide to the obtained second leaching solution under various conditions. In addition, sodium hydrosulfide was dissolved in distilled water and added in the form of a solution.

[0031] The conditions for the sulfide precipitation treatment were as follows.

[0032] Second extract: 100mL

[0033] Type of sulfide: Sodium hydrosulfide

[0034] Amount of sulfide added: 1 to 3 equivalents as sulfur (S) relative to dissolved zinc

[0035] pH of the second leaching solution during the reaction: 0.5–5

[0036] pH adjuster: 3M sulfuric acid or 100g / L sodium hydroxide (NaOH)

[0037] Treatment time: Stirring for 0.5 hours after addition of sodium hydrosulfide

[0038] Then, after the sulfide precipitation treatment, solid-liquid separation was performed by suction filtration using a filter paper with a pore size of 1 μm (zinc separation process), and the components (zinc, iron, manganese) of the separated third solution were quantitatively analyzed using ICP emission analysis. Since most of the zinc had been removed in the prior acid and oxidizing agent treatment process, no clogging of the filter paper was observed during the zinc separation process, allowing for easy solid-liquid separation. In addition, the obtained analysis values ​​were corrected for the effect of dilution caused by the addition of sodium hydrosulfide solution and a pH adjuster. The obtained results are shown in Figure 5.

[0039] From FIG. 5(a), it can be seen that when the amount of sulfide added is 1 equivalent (sodium hydrosulfide: 1 equivalent), the precipitation of zinc is removed, but it is incomplete as it exceeds the analytical limit (0.1 mg / L), and also that the final zinc removal rate is not stable when the pH of the second leaching solution is increased.

[0040] Meanwhile, as shown in FIG. 5(b), when the amount of sulfide added is 2 equivalents (sodium hydrosulfide: 2 equivalents), the removal of zinc precipitate is significant. In particular, under conditions where the pH of the second leaching solution is 3 or higher, it can be seen that zinc is removed until the zinc concentration in the third solution after the zinc removal process (sulfide precipitation treatment process and zinc separation process) falls below the analytical limit (0.1 mg / L). Furthermore, when the amount of sulfide added as shown in FIG. 5(c) is 3 equivalents (sodium hydrosulfide: 3 equivalents), a similar trend is observed as in the case of 2 equivalents. In particular, when the pH of the second leaching solution is 3 or higher, the zinc concentration falls below the analytical limit (0.1 mg / L), and the removal of zinc precipitate is significant.

[0041] In addition, as shown in Fig. 5, it can be seen that the precipitation of iron is also removed by the zinc removal process. As shown in Fig. 5(b), when the amount of sulfide added is 2 equivalents (sodium hydrosulfide: 2 equivalents), iron is precipitated and removed under conditions where the pH of the second leaching solution is 3 or higher, and when the pH is about 5, the iron concentration is reduced to about 1 mg / L. Under these conditions shown in Fig. 5(b), some manganese is also precipitated due to the increase in pH, but in this invention, the first leaching residue, which maintains a high manganese content through an acid and oxidizing agent treatment process, is used. Therefore, the manganese concentration in the third solution, which was previously reduced to about 19,000 mg / L, could be suppressed to about 25,000 mg / L.

[0042] In addition, it can be seen that iron is precipitated and removed even when the amount of sulfide added as shown in Fig. 5(c) is 3 equivalents (sodium hydrosulfide: 3 equivalents), showing a similar trend as when it is 2 equivalents. As shown in Fig. 5(c), it can be seen that the precipitation and removal of iron is particularly significant when the pH of the second leaching solution is 5, and it is removed until it reaches about 0.5 mg / L. In Fig. 5(c), when the pH is 5, some manganese is also precipitated due to the increase in pH, but in this invention, the first leaching residue, which maintains a high manganese content through an acid and oxidizing agent treatment process, is used. Therefore, the manganese concentration in the third solution, which was previously reduced to about 15,000 mg / L, could be suppressed to about 23,000 mg / L.

[0043] As described above regarding Experiment (A), using the first leaching residue obtained by treating the powder with an acid-oxidizing agent is advantageous for increasing the yield of finally recovered manganese because a large amount of zinc is removed while manganese is retained. Furthermore, the amount of zinc-containing precipitate is reduced by the zinc removal process on the second leaching solution containing manganese ions, iron ions, and remaining zinc ions obtained by performing an acid-reducing agent treatment process. Consequently, the co-precipitation of manganese during zinc precipitation can be suppressed, and troubles such as clogging of the filter paper during zinc separation can be avoided, allowing the zinc component to be precipitated and separated without interruption down to below the analytical limit. Additionally, there are cases where some iron is precipitated along with zinc. If the iron concentration has been precipitated and removed to a certain extent, it is also conceivable to end the treatment at this stage. However, in order to remove iron to a greater degree, an iron removal process (oxidation treatment process and iron separation process) was additionally carried out to precipitate iron ions contained in the third solution separated after the zinc removal process as iron-containing precipitates such as hydroxides.

[0044] Experiment (B)

[0045] According to the same method as in Experiment (A), an acid-reducing agent treatment was performed on the first leaching residue obtained through a screening process, a crushing and sieving process, an acid-oxidizing agent treatment process, and a first solid-liquid separation process by applying an acid solution and a reducing agent, thereby obtaining a second leaching solution and a second leaching residue. The manganese, zinc, and iron concentrations in the separated second leaching solution were measured by ICP emission analysis, and the manganese concentration was 31826 mg / L, the zinc concentration was 1919 mg / L, and the iron concentration was 163 mg / L.

[0046] Next, air aeration was performed on the obtained second leachate as an oxidation treatment (oxidation treatment process). The conditions for air aeration were as follows.

[0047] Injection rate: (Equal volume to the second leaching liquid) / min

[0048] Aeration time: 30 minutes

[0049] pH of the second leaching solution during the reaction: 4–6

[0050] pH adjuster: 3M sulfuric acid or 100g / L sodium hydroxide

[0051] Here, the injection rate and aeration time are within the range of normal practical conditions (injection rate: 0.1 to 1 times the amount of solution / min, aeration time: 15 to 60 minutes).

[0052] Then, the entire volume of the second leaching solution after air aeration was separated into solid and liquid phases by suction filtration using a filter paper with a pore size of 1 μm (iron separation process), and the component concentrations (zinc, iron, manganese) of the separated third solution were measured using ICP emission analysis. Additionally, the effects of dilution by a pH adjuster were corrected for the obtained measurements. The results obtained are shown in Fig. 6. Since almost no precipitation of manganese and zinc was observed due to the oxidation treatment process, Fig. 6 shows only the iron concentration in the third solution after the iron removal process (oxidation treatment process and iron separation process).

[0053] From Fig. 6, it can be seen that iron is selectively precipitated and removed in the second leaching solution at pH: 4 to 6. Additionally, although not shown, manganese and zinc hardly precipitate in this pH range, and at pH: 6, although zinc was slightly precipitated and removed, the amount was small, approximately 10 to 20 mg / L. When the second leaching solution is at pH: 5 or 6, the precipitation and removal of iron proceeds significantly, and the iron concentration is reduced to below 0.1 mg / L. Thus, the iron concentration could be significantly reduced simply by performing air aeration, an inexpensive oxidation treatment, on the second leaching solution.

[0054] In Fig. 6, air aeration (oxidation treatment) was performed on the second leaching solution adjusted to pH: 5 to reduce the iron concentration to less than 0.1 mg / L, and a third solution obtained by performing an iron separation process by solid-liquid separation was additionally subjected to a sulfide precipitation treatment process under various conditions.

[0055] The conditions for the sulfide precipitation treatment were as follows.

[0056] Solution 3: 100mL

[0057] Type of sulfide: Sodium hydrosulfide

[0058] Amount of sulfide added: 1 to 3 equivalents as sulfur relative to dissolved zinc

[0059] pH of the third solution during the reaction: 0.5–5

[0060] pH adjuster: 3M sulfuric acid or 100g / L sodium hydroxide

[0061] Treatment time: Stirring for 0.5 hours after addition of sodium hydrosulfide

[0062] After the above-described sulfide precipitation treatment process, solid-liquid separation was performed by suction filtration using a filter paper with a pore size of 1 μm (zinc separation process), and the components of the separated fourth solution were analyzed by ICP emission analysis. Since most of the zinc had been removed in the acid and oxidizing agent treatment process beforehand, no clogging of the filter paper was detected during the zinc separation process, allowing for easy solid-liquid separation.

[0063] As a result, when the amount of sulfide added was 1 equivalent (sodium hydrosulfide: 1 equivalent), the precipitation of zinc was removed, but it was incomplete as it exceeded the analytical limit (0.1 mg / L), and also, the final zinc removal rate was not stable when the pH of the third solution was increased.

[0064] Meanwhile, when the amount of added sulfide is 2 equivalents (sodium hydrosulfide: 2 equivalents), the removal of zinc precipitation becomes significant, and in particular, under conditions where the pH of the third solution is 3 or higher, zinc concentration in the fourth solution after the zinc removal process is precipitated and removed until it is less than the analytical limit (0.1 mg / L).

[0065] In addition, even when the amount of added sulfide was 3 equivalents (sodium hydrosulfide: 3 equivalents), it showed a similar trend as when it was 2 equivalents, and the removal of zinc precipitate was significant. Furthermore, even when the amount of added sulfide was 3 equivalents (sodium hydrosulfide: 3 equivalents) and the pH of the third solution was about 5, since the first leaching residue, which maintained a high manganese content through an acid and oxidizing agent treatment process, was used, the manganese concentration in the fourth solution, which had previously been reduced to about 16,000 mg / L, could be suppressed to about 22,000 mg / L.

[0066] As described above regarding experiment (B), if the first leaching residue obtained by performing an acid-oxidizing agent treatment process on the powder is used, a large amount of zinc is removed while manganese is retained, which is advantageous for increasing the yield of manganese recovered at the end. In addition, if an oxidation treatment is first performed on the second leaching solution containing manganese ions, iron ions, and remaining zinc ions obtained by performing an acid-reducing agent treatment process, the solution can be prepared in which most of the iron components are precipitated and separated by simply performing an oxidation treatment such as air aeration (iron removal process). Then, if a sulfide precipitation treatment process is performed by applying a sulfide to the separated third solution, the amount of zinc-containing precipitate is reduced, so co-precipitation of manganese during zinc precipitation can be suppressed, and troubles such as clogging of the filter paper during zinc separation can be avoided, allowing the zinc components to be precipitated and removed to below the analytical limit without interruption (zinc removal process).

[0067] As such, according to experiments (A) and (B), by using a first leaching residue in which most of the zinc in the separated particles has been removed in advance during the acid / oxidizing agent treatment process as a pretreatment process, zinc and iron can be reliably and easily precipitated and separated together regardless of the process order of the zinc removal process and the iron removal process, and it was recognized that a high-purity manganese-containing solution with a high manganese yield can be produced.

[0068] The present invention was completed by further examining the findings based on this understanding. That is, the gist of the present invention is as follows.

[0069] (1) A sorting process for sorting one or both of manganese batteries and alkaline manganese batteries from waste batteries, and

[0070] A crushing and sieving process to obtain a separated body by crushing and sieving one or both of the manganese batteries and alkaline manganese batteries selected in the above sorting process, and

[0071] An acid and oxidizing agent treatment process in which an acid solution and an oxidizing agent are mixed with the powder obtained from the crushing and sieving process to obtain a first leaching solution and a first leaching residue, and

[0072] A first solid-liquid separation process for separating the first leaching solution and the first leaching residue obtained from the above acid-oxidizing agent treatment process, and

[0073] An acid-reducing agent treatment process for obtaining a second leaching solution and a second leaching residue by mixing an acid solution and a reducing agent with the first leaching residue separated in the first solid-liquid separation process, and

[0074] A second solid-liquid separation process for separating the second leaching liquid and the second leaching residue obtained from the acid-reducing agent treatment process, and

[0075] A manganese extraction process for obtaining a solution containing manganese ions by removing zinc ions and iron ions from the second leaching solution separated in the second solid-liquid separation process, among the zinc ions, iron ions, and manganese ions contained in the second leaching solution.

[0076] Perform in this order,

[0077] The above manganese extraction process,

[0078] A zinc removal process comprising a sulfide precipitation treatment process for precipitating the zinc ions by reacting a sulfide with the zinc ions, and additionally, a zinc separation process for separating the obtained zinc-containing precipitate;

[0079] An iron removal process comprising an oxidation treatment process for oxidizing the iron ions to precipitate the iron ions, and additionally, an iron separation process for separating the obtained iron-containing precipitate;

[0080] A method for recovering manganese contained in waste batteries, including in no particular order.

[0081] (2) The oxidizing agent in the above acid-oxidizing agent treatment process is any one of sodium hypochlorite solution, oxygen, ozone, or potassium permanganate solution, the recovery method described in (1).

[0082] (3) The acid solution in the above acid / oxidizing agent treatment process is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less, as described in (1) or (2) for recovery.

[0083] (4) A recovery method described in any one of (1) to (3), wherein the solid-liquid ratio of the powder and the acid solution in the above acid-oxidizing agent treatment process is 50 g / L or more.

[0084] (5) A recovery method described in any one of (1) to (4), wherein the acid solution in the above acid-reducing agent treatment process is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less.

[0085] (6) A recovery method described in any one of claims (1) to (5), wherein the reducing agent in the above acid-reducing agent treatment process is one of hydrogen peroxide, sodium sulfide, sodium bisulfite, sodium thiosulfate, and iron sulfate.

[0086] (7) The above manganese extraction process is carried out in the order of the above zinc removal process, followed by the above iron removal process, and

[0087] In the above zinc removal process, a sulfide precipitation treatment process is performed in which a sulfide is applied to the second leaching solution to precipitate zinc ions in the second leaching solution, and then a zinc separation process is performed to separate the obtained zinc-containing precipitate from a third solution containing manganese ions and iron ions.

[0088] A recovery method described in any one of claims (1) to (6), wherein in the above iron removal process, an oxidation treatment process is performed to oxidize the third solution obtained from the above zinc removal process to precipitate iron ions in the third solution, and then an iron separation process is performed to separate the obtained iron-containing precipitate and the fourth solution containing manganese ions from solid to liquid.

[0089] (8) In the above sulfide precipitation treatment process, the recovery method described in (7) adjusts the pH of the second leaching solution to 2 or higher and 6 or lower.

[0090] (9) In the above oxidation treatment process, the recovery method described in (7) or (8) involves air aeration of the third solution containing manganese ions and iron ions, or additionally adding an oxidizing agent to the third solution and adjusting the pH of the third solution to 3 or higher and 7 or lower.

[0091] (10) The above manganese extraction process is carried out in the order of the above iron removal process, followed by the above zinc removal process, and

[0092] In the above iron removal process, after performing an oxidation treatment process to oxidize the second leaching solution to precipitate iron ions in the second leaching solution, an iron separation process is performed to separate the obtained iron-containing precipitate from a third solution containing manganese ions and zinc ions.

[0093] A recovery method described in any one of claims (1) to (6), wherein in the above zinc removal process, a sulfide precipitation treatment process is performed to precipitate zinc ions in the third solution obtained from the above iron removal process by reacting a sulfide with the third solution, and then a zinc separation process is performed to separate the obtained zinc-containing precipitate and the fourth solution containing manganese ions from solid to liquid.

[0094] (11) A recovery method described in (10) in which, in the above sulfide precipitation treatment process, the third solution containing manganese ions and zinc ions is adjusted to a pH of 2 or higher and 6 or lower.

[0095] (12) In the above oxidation treatment process, the second leaching solution is air-aerated, and the second leaching solution is adjusted to a pH of 3 or higher and 7 or lower, as described in (10) or (11).

[0096] (13) A recovery method described in any one of (1) to (12), wherein the sulfide used in the above sulfide precipitation treatment process is one of sodium hydrosulfide, sodium sulfide, or hydrogen sulfide.

[0097] (14) A sorting device for sorting one or both of manganese batteries and alkaline manganese batteries from waste batteries, and

[0098] A crushing device that loads one or both of the manganese batteries and alkaline manganese batteries selected by the sorting device and performs a crushing process to obtain a crushed product, and

[0099] A sieving device that obtains a granular body by performing sieving treatment on the crushed product obtained from the crushing device, and

[0100] An acid-oxidizing agent treatment tank for applying an acid solution and an oxidizing agent to the powder obtained from the above-mentioned sieve separation device, and

[0101] A first solid-liquid separation device for separating the first leaching liquid and the first leaching residue obtained from the above acid-oxidizing agent treatment tank, and

[0102] An acid-reducing agent treatment tank for applying an acid solution and a reducing agent to the first leaching residue separated in the first solid-liquid separation device, and

[0103] A second solid-liquid separation device for separating the second leaching liquid and the second leaching residue obtained from the acid-reducing agent treatment tank above, and

[0104] A group of manganese extraction devices that, from the second leaching liquid separated in the second solid-liquid separation device, remove zinc ions and iron ions among the zinc ions, iron ions, and manganese ions contained in the second leaching liquid, and obtain a solution containing manganese ions.

[0105] Prepare in this order,

[0106] The above group of manganese extraction devices,

[0107] A group of zinc removal devices comprising a sulfide precipitation treatment tank that precipitates the zinc ions by reacting the zinc ions with a sulfide, and additionally, a zinc separation device that separates solids and liquids from the obtained zinc-containing precipitate;

[0108] A group of iron removal devices comprising an oxidation treatment tank that oxidizes the iron ions to precipitate the iron ions, and additionally, an iron separation device that separates the obtained iron-containing precipitate from solid to liquid;

[0109] A recovery facility for manganese contained in waste batteries, including in no particular order. Effects of the invention

[0110] According to the present invention, manganese, a valuable component contained in waste batteries, can be separated from zinc and iron components with high precision and ease, and high-purity manganese, which can be used as a raw material for secondary battery electrodes, can be recovered at a low cost with a high yield, thereby exhibiting special industrial effects. Brief explanation of the drawing

[0111] Figure 1 is a flowchart illustrating the manganese recovery process shown in Patent Document 1. Figure 2 is a flowchart illustrating the process of the manganese recovery method of the present invention. FIG. 3 is a flowchart illustrating one embodiment (sequence A) of the method for recovering manganese according to the present invention. FIG. 4 is a flowchart illustrating another embodiment (sequence B) of the method for recovering manganese of the present invention. Figure 5 is a graph showing the effect of the amount of sulfide added ((a) sodium hydrosulfide: 1 equivalent, (b) sodium hydrosulfide: 2 equivalents, (c) sodium hydrosulfide: 3 equivalents) and pH conditions on the removal of precipitates of zinc, iron, and manganese in the sulfide precipitation treatment process according to the flow of Figure 3. Figure 6 is a graph showing the effect of pH on the removal of iron precipitates in an oxidation treatment process according to the flow of Figure 4. FIG. 7 is a schematic diagram illustrating one embodiment (configuration A) of the manganese recovery facility of the present invention. FIG. 8 is a schematic diagram illustrating another embodiment (configuration B) of the manganese recovery facility of the present invention. Figure 9 is a graph showing the effect of the amount of oxidizing agent added on the leaching removal of manganese and zinc in the acid and oxidizing agent treatment process. Specific details for implementing the invention

[0112] (Form for carrying out the invention)

[0113] The present invention relates to a method for recovering manganese and a recovery facility for separating the manganese component, which is a valuable component contained in a waste battery, from the zinc and iron components also contained in the waste battery, and recovering it with a high yield as a high-purity manganese-containing solution, with respect to waste batteries. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments represent suitable examples of the present invention, and the present invention is not limited in any way by these examples.

[0114] (Manganese recovery method)

[0115] As shown in FIG. 2, the manganese recovery method of the present invention comprises, in order, a screening process, a crushing and sieving process, an acid and oxidizing agent treatment process, a first solid-liquid separation process, an acid and reducing agent treatment process, a second solid-liquid separation process, and a manganese extraction process. In addition, the manganese extraction process includes a predetermined zinc removal process and an iron removal process in no particular order.

[0116] By following the above-described process, the recovery method of the present invention can reliably and conveniently remove components other than manganese contained in waste batteries in sequence. As a result, according to the recovery method of the present invention, the manganese component can be easily recovered with a high yield and with a high purity sufficient to be used as a raw material for secondary battery electrode materials using waste batteries. The recovery method of the present invention can be suitably carried out using the manganese recovery facility described below.

[0117] sorting process

[0118] It is common for waste batteries to be collected in a mixed form containing various types of batteries. Therefore, in the present invention, one or both (manganese batteries and / or alkaline manganese batteries) are separated from the collected waste batteries. In order to efficiently extract the manganese component in a subsequent process, only manganese batteries may be separated, only alkaline manganese batteries may be separated, or both manganese batteries and alkaline manganese batteries may be separated. Any method may be used as the separation method, such as manual separation or mechanical separation using a separation device.

[0119] Crushing and sieving processes

[0120] Next, the manganese batteries and / or alkaline manganese batteries selected in the screening process are crushed. The purpose of crushing is to exclude, as much as possible, materials containing components other than manganese, zinc, and carbon from the constituent materials of the manganese batteries and / or alkaline manganese batteries selected in the screening process.

[0121] When these waste batteries are crushed, packaging materials (iron, plastic, paper, etc.), zinc cans which are negative electrode materials for manganese batteries, and brass rods which are current collectors for alkaline manganese batteries become thin or flat solids. Meanwhile, manganese dioxide which is the positive electrode material, carbon rods which are current collectors for manganese batteries, zinc powder which is the negative electrode material for alkaline manganese batteries, compounds such as manganese oxyhydroxide, zinc hydroxide, manganese hydroxide, and zinc oxide generated by discharge, and various electrolytes become finer particles than the thin or flat solids.

[0122] Typically, a crushing device is used to crush waste batteries. The type of crushing device is not particularly limited, but, for example, it is desirable to have a type that allows solid materials, such as packaging materials constituting the battery, to be easily separated from granular materials after crushing. Examples of such crushing devices include a two-axis rotary crushing device.

[0123] The mesh size of the sieve used for sieving the above-mentioned crushed material (sieving between the thin or flake-shaped solid material and the granular material) is generally preferably 1 mm or more, preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 3 mm or less. The mesh size of the sieve is preferably about 1 to 20 mm, more preferably about 1 to 10 mm, and even more preferably about 1 to 3 mm. If the mesh size of the sieve is above the lower limit, a larger amount of granular material containing manganese components can be secured. In addition, if the mesh size of the sieve is below the upper limit, solid material containing components other than manganese can be further excluded, allowing subsequent processes to be carried out more efficiently.

[0124] Therefore, after crushing the waste batteries, if they are sieved using the aforementioned mesh size sieve, large solid materials such as packaging materials are removed from the waste batteries, and a powder containing carbon, mainly manganese and zinc components, can be efficiently obtained.

[0125] Thus, the powder obtained through the crushing and sieving process is a powder mixed with manganese dioxide, carbon, zinc chloride or ammonium chloride, potassium hydroxide, and furthermore, manganese oxyhydroxide, zinc hydroxide, manganese hydroxide, zinc oxide, etc. generated by discharge, which are the main constituent materials of manganese batteries and / or alkaline manganese batteries. In addition, iron components are inevitably incorporated into this powder.

[0126] Acid and Oxidizing Agent Treatment Process

[0127] The acid and oxidizing agent treatment process is an important process that characterizes the recovery method of the present invention. In the acid and oxidizing agent treatment process, an acid solution and an oxidizing agent are mixed with the powder obtained through the crushing and sieving process. By acting an oxidizing agent in addition to the acid solution, the hydration of manganese in the powder is increased, thereby preventing manganese from leaching into the first leaching solution while allowing mainly only the zinc in the powder to be leached into the first leaching solution. As a result, a first leaching residue with a high manganese content and significantly reduced zinc content can be obtained, which is advantageous for increasing the manganese yield.

[0128] The acid used in the acid solution for the acid and oxidizing agent treatment process may be a general acid, and sulfuric acid, nitric acid (HNO3), hydrochloric acid (HCl), or other acids may be used. Although the choice can be made appropriately depending on the price or purpose, it is preferable to use sulfuric acid or hydrochloric acid as the acid solution when considering factors such as cost and ease of procurement.

[0129] When using sulfuric acid, it is preferable to use dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less. More specifically, the sulfuric acid concentration is preferably 1.4% or more, more preferably 2% or more, even more preferably 5% or more, preferably 45% or less, more preferably 30% or less, and even more preferably 25% or less. The sulfuric acid is more preferably dilute sulfuric acid with a concentration of 2% or more and 30% or less, and even more preferably dilute sulfuric acid with a concentration of 5% or more and 25% or less.

[0130] When using hydrochloric acid, it is preferable to use dilute hydrochloric acid with a mass concentration of 1% or more and 14% or less. More specifically, the hydrochloric acid concentration is preferably 1% or more, more preferably 2% or more, more preferably 14% or less, and more preferably 8% or less. It is more preferable that the hydrochloric acid be dilute hydrochloric acid with a concentration of 2% or more and 8% or less.

[0131] If the concentration of the acid solution in the acid and oxidizing agent treatment process does not meet the above lower limit, it is difficult to sufficiently leach the zinc components in the separated particles using the first leaching solution, and a large amount of fine zinc-containing precipitates is likely to be generated in the subsequent zinc removal process. As a result, manganese is prone to co-precipitation during the zinc separation process, which becomes a factor in the reduction of manganese yield. Furthermore, the zinc-containing precipitates cause clogging of the mesh of filter paper, filter cloth, etc., making it difficult to easily remove the zinc components. On the other hand, if the concentration of the acid solution in the acid and oxidizing agent treatment process exceeds the above upper limit, even the manganese intended for recovery is prone to being excessively leached using the first leaching solution, making it difficult to finally obtain a high-concentration manganese-containing solution with a high yield.

[0132] Any commercially available sulfuric acid or hydrochloric acid can be used, but the cost of the acid solution can be reduced by using diluted industrial acid or waste acid with low levels of hazardous metal components. In addition, the “mass% concentration” here is the value obtained by dividing the mass of the acid in the acid solution by the total mass of the acid solution and multiplying the result by 100.

[0133] Furthermore, regardless of which acid solution is used, the acid concentration required for the leaching of zinc components varies depending on the solid-to-liquid ratio of the powder to the acid solution, the amount of the powder, the zinc content in the powder, and the form of zinc in the powder. Therefore, it is desirable to determine the optimal acid concentration by conducting preliminary experiments that anticipate actual conditions.

[0134] The oxidizing agent used in the acid-oxidizing agent treatment process is added to suppress the dissolution of manganese. The type of oxidizing agent is not specifically defined, and general oxidizing agents may be used. However, oxidizing agents containing heavy metals other than manganese, such as potassium dichromate (K2Cr2O7), may cause the heavy metal components to remain as impurities in the manganese. Therefore, it is preferable to use an oxidizing agent that does not contain heavy metals other than manganese, such as sodium hypochlorite solution, oxygen (O2), ozone (O3), or potassium permanganate (KMnO4) solution, and it is more preferable to use a sodium hypochlorite solution from the perspective of the cost and oxidizing power of the oxidizing agent. In addition, hydrogen peroxide is unsuitable because it acts as a reducing agent in this system.

[0135] When the oxidizing agent is a gas such as oxygen or ozone, the oxidizing agent can be added by blowing it into the acid solution. The amount of oxidizing agent blown in can be, for example, 0.25 to 3 times the volume of the acid solution (e.g., 25 to 300 mL / min of oxidizing agent per 100 mL of acid solution), and is finally determined through preliminary experiments.

[0136] In the acid and oxidizing agent treatment process, the solid-to-liquid ratio (powder (g) / acid solution (L)) of the powder and acid solution is preferably 50 g / L or higher, more preferably 100 g / L or higher, and preferably 500 g / L or lower. If the solid-to-liquid ratio does not meet the above lower limit, the size of the reaction vessel required to treat the powder increases, thereby increasing equipment costs. Furthermore, if the acid solution becomes excessive relative to the powder, it becomes easy for the target component, manganese, to leach into the first leaching solution. On the other hand, if the solid-to-liquid ratio exceeds the above upper limit, the viscosity of the mixture of the powder and acid solution increases, making it difficult to stir sufficiently. Additionally, if the acid solution becomes insufficient relative to the powder, it becomes difficult for the acid solution to sufficiently leach zinc into the first leaching solution, making it difficult to efficiently remove zinc components from the powder.

[0137] The above suitable solid-liquid ratio does not matter whether the oxidizing agent being mixed is a liquid such as sodium hypochlorite solution and potassium permanganate solution, or a gas such as oxygen and ozone.

[0138] For example, when the oxidizing agent is a liquid such as sodium hypochlorite, the amount of oxidizing agent added in the acid-oxidizing agent treatment process is preferably 20 mass% or more and 50 mass% or more with respect to the acid solution, from the perspective of incorporating manganese components into the first leaching residue in a high yield. In addition, the effective chlorine concentration of the sodium hypochlorite used is preferably 5% or more. The stirring temperature in the acid-oxidizing agent treatment process is not particularly limited, but is typically 0 to 100°C, and the stirring time is preferably 30 minutes or more and preferably 120 minutes or less. This is because if the stirring time is less than 30 minutes, there is a risk that the reaction will not be completed, and if it exceeds 2 hours, it becomes difficult for the reaction to proceed further.

[0139] For example, when the oxidizing agent is a gas such as oxygen and ozone, the amount of oxidizing agent blown in is preferably 0.25 times or more the volume of the acid solution, and preferably 3 times or less. The stirring temperature and stirring time are the same as those for the liquid oxidizing agent described above.

[0140] 1st solid-liquid separation process

[0141] In the first solid-liquid separation process, the first leaching solution and the first leaching residue obtained from the acid and oxidizing agent treatment process are separated into solid and liquid phases. The separated first leaching solution typically contains mainly leached zinc ions, and may additionally contain manganese ions and iron ions that are partially dissolved along with zinc. However, in the present invention, since the dissolution of manganese is suppressed by the addition of an oxidizing agent, the manganese content in the first leaching solution is controlled to be lower than in the conventional method. Meanwhile, the separated solid first leaching residue mainly contains manganese and iron, and residual zinc. In the present invention, since the dissolution of manganese is suppressed by the addition of an oxidizing agent, the manganese content in the first leaching residue is controlled to be higher than in the conventional method, and can achieve more than 50 mass%, and furthermore 55 mass% or more, as shown in Table 1, for example.

[0142] The means for solid-liquid separation are not particularly limited. For the solid-liquid separation process, it is preferable to use a means selected from commercially available methods, such as gravity sedimentation, filtration, centrifugation, filter press, membrane separation, etc.

[0143] Acid and reducing agent treatment process

[0144] In the acid-reducing agent treatment process, an acid solution and a reducing agent are mixed with the first leaching residue obtained through the acid-oxidizing agent treatment process and the first solid-liquid separation process, and the manganese component contained in the first leaching residue is almost completely leached into the second leaching solution obtained in the next process. Since the first leaching residue that has undergone the acid-oxidizing agent treatment process contains manganese in a high yield, it is easy to increase the yield of manganese in the second leaching solution obtained using the first leaching residue.

[0145] Here, "almost completely" in this specification refers to a state in which, when a residue sample (in this case, the second leaching residue) after a certain process is measured according to an analytical method specified in commercial JIS standards, the amount of the target component (in this case, manganese) is less than the analytical limit, for example, less than 0.1 mg / L.

[0146] The acid solution in the acid-reducing agent treatment process is added in combination with the reducing agent primarily to further leach the zinc component remaining in the first leaching residue, while also leaching the manganese component. The acid used in the acid solution may be a general acid and can be adapted to suit the type and conditions of the acid in the aforementioned acid-oxidizing agent treatment process.

[0147] If the concentration of the acid solution in the acid-reducing agent treatment process does not meet the aforementioned lower limit, it is difficult to sufficiently leach the manganese components in the first leaching residue into the second leaching solution, and the manganese recovery rate (yield) is likely to decrease. On the other hand, if the concentration of the acid solution in the acid-reducing agent treatment process exceeds the aforementioned upper limit, the amount of alkali agent required for pH adjustment in the subsequent process increases, raising concerns about increased costs.

[0148] In addition, regarding the zinc components remaining in the first leaching residue after the acid and oxidizing agent treatment process, they are almost completely dissolved (leached) as the acid concentration is increased, regardless of the presence or absence of a reducing agent.

[0149] In addition, from the perspective of improving the efficiency of acid-reducing agent treatment, it is desirable to set the solid-liquid ratio of the first leaching residue to the acid solution (first leaching residue (g) / acid solution (L)) in the acid-reducing agent treatment process to 50 g / L or higher. On the other hand, if the solid-liquid ratio exceeds 800 g / L, the viscosity increases, which may cause handling problems or worsen the yield during the solid-liquid separation process. For this reason, it is desirable to keep the solid-liquid ratio at 800 g / L or lower. Furthermore, regarding the treatment temperature (atmosphere temperature, acid solution temperature, etc.) for the acid-reducing agent treatment, sufficient effect can be obtained even at room temperature (around 15 to 25°C), but heating may also be performed. The heating temperature can be, for example, 60 to 80°C. If heating is performed, an improvement in reaction efficiency can be expected as the temperature is increased within the range where the treatment solution does not boil. The treatment time for acid and reducing agent treatment is preferably 5 minutes or more, and preferably 6 hours or less.

[0150] The reducing agent is primarily added to effectively leach manganese components with valencies that are difficult to dissolve in acid, such as trivalent and tetravalent compounds, contained in the first leaching residue, and various commercially available reducing agents can be applied. Suitable examples of reducing agents include hydrogen peroxide, sodium sulfide (Na2S·9H2O), sodium bisulfite (NaHSO3), sodium thiosulfate (Na2S2O3), and iron sulfate (FeSO4·7H2O). Sulfur-based reducing agents may generate corrosive gases such as sulfur dioxide (SO2) and hydrogen sulfide (H2S), so caution is required from the perspective of safety. From this perspective, it is more preferable to use hydrogen peroxide as the reducing agent.

[0151] In addition, the amount of reducing agent added (g) is not specifically limited as it depends on the form of manganese contained in the first leaching residue, but it is sufficient to have about 1 to 500 g / L per acid solution (L).

[0152] Second high-liquid separation process

[0153] In the second solid-liquid separation process, the second leaching solution and the second leaching residue obtained from the acid-reducing agent treatment process are separated into solid and liquid phases. The separated second leaching solution contains manganese ions, iron ions, and residual zinc ions. Meanwhile, the separated solid second leaching residue is the result of residual carbon. Accordingly, the carbon can be separated from the manganese, zinc, and iron components contained in the first leaching residue and the separated powder.

[0154] The means for solid-liquid separation are not particularly limited. For the solid-liquid separation process, it is preferable to use a means selected from commercially available methods, such as gravity sedimentation, filtration, centrifugation, filter press, membrane separation, etc.

[0155] Manganese extraction process

[0156] It is necessary to perform a manganese extraction process to remove zinc ions and iron ions from the second leaching solution separated in the second solid-liquid separation process, and to obtain a high-purity solution containing manganese ions (manganese-containing solution). Specifically, the manganese extraction process includes a predetermined zinc removal process and an iron removal process in no particular order. More specifically, the zinc removal process included in the manganese extraction process includes a sulfide precipitation treatment process that precipitates zinc ions by reacting a sulfide with zinc ions, and a zinc separation process that separates the obtained zinc-containing precipitate. Additionally, the iron removal process included in the manganese extraction process includes an oxidation treatment process that precipitates iron ions by oxidizing iron ions, and an iron separation process that separates the obtained iron-containing precipitate.

[0157] In this way, in the manganese extraction process, zinc ions and iron ions are selectively precipitated, respectively, and by reliably removing zinc ions and iron ions from the second leaching solution, the target component, manganese, can finally be easily recovered with high purity and high yield.

[0158] In the manganese extraction process, a zinc removal process that preferentially precipitates and removes zinc ions may be performed first (Step A), or an iron removal process that preferentially precipitates and removes iron ions may be performed first (Step B). From the perspective of making the process easier to simplify, it is preferable to perform the iron removal process first (Step B).

[0159] In step A, first, a mixture of a zinc-containing precipitate and a third solution containing manganese ions and iron ions is obtained from the second leaching solution, and then these are separated. Also, in step B, first, a mixture of an iron-containing precipitate and a third solution containing manganese ions and zinc ions is obtained from the second leaching solution, and then these are separated. Steps A and B are described in detail below.

[0160] Zinc removal process (sequence A)

[0161] In the zinc removal process of sequence (A), a sulfide precipitation treatment process is first performed on the solid-liquid separated second leaching solution. In this sulfide precipitation treatment process, a sulfide is applied to the second leaching solution to precipitate the zinc ions, which are mainly the remaining ions among those contained in the second leaching solution, as zinc sulfide, making them removable from the second leaching solution. Through this treatment, a mixture of a third solution containing manganese ions and iron ions and a zinc-containing precipitate is obtained from the second leaching solution.

[0162] The second leaching solution separated in the second solid-liquid separation process contains manganese ions, iron ions, and additionally remaining zinc ions, and when a sulfide is applied to the second leaching solution, the included divalent metal ions are sulfide ions (S 2- It reacts with ) to form a sulfide and precipitates. The ease of this sulfide precipitation is due to the solubility product K SP It depends on. The solubility product of manganese, zinc, and iron sulfides is shown below.

[0163] MnS: KSP = 2.5 × 10 －10

[0164] ZnS: K SP = 1.6 × 10 －24

[0165] FeS: K SP = 6.3×10 －18

[0166] (Lange, NA: Lange's Handbook of Chemistry. Thirteenth edition 1985)

[0167] Solubility product K SP As the value of is smaller, it is easier to form sulfides, so among manganese, zinc, and iron, zinc is the most likely to form sulfides. Therefore, when a sulfide is applied to a second leaching solution containing ions of manganese, zinc, and iron, zinc can be selectively precipitated as a sulfide. Furthermore, by adjusting the concentration of sulfide ions and the pH of the second leaching solution, the concentration of zinc ions in the second leaching solution can be easily reduced to below the analytical limit (0.1 mg / L).

[0168] Here, as described above, if the second leaching solution contains a large amount of zinc ions, a large amount of fine zinc-containing precipitate is generated by the sulfide precipitation treatment process, which promotes the co-precipitation of manganese and tends to lower the final manganese yield. Furthermore, during the subsequent solid-liquid separation, the filter cloth and the like are prone to clogging, making the zinc separation process difficult. However, in the present invention, in the acid / oxidizing agent treatment process preceding the sulfide precipitation treatment process, most of the zinc components in the separated particles are removed in advance while the manganese components are retained, so the co-precipitation of manganese can be effectively avoided and the final manganese yield can be increased. In addition, the quantity and quality of the zinc-containing precipitate can be controlled, allowing the zinc separation process described later to be performed simply and efficiently.

[0169] Suitable examples of sulfides to be reacted include sodium hydrosulfide, sodium sulfide (NaS), and hydrogen sulfide. Additionally, since hydrogen sulfide is a gas, it needs to be aerated. Therefore, sodium hydrosulfide and sodium sulfide are more preferred as sulfides to be reacted.

[0170] It is preferable that the amount of sulfide to be applied be 1.1 equivalents or more and 5 equivalents or less as sulfur relative to molten zinc. The amount of sulfide is preferably 1.1 equivalents or more relative to molten zinc, more preferably 2 equivalents or more, preferably 5 equivalents or less, more preferably 3 equivalents or less, and even more preferably less than 3 equivalents. If the amount of sulfide is above the above lower limit, zinc ions can be precipitated more effectively. Furthermore, if the amount of sulfide is below the above lower limit, it is easier to suppress the unintended precipitation of manganese ions, and it is possible to prevent the amount of sulfide to be applied from becoming excessive and thus economically disadvantageous.

[0171] In addition, when the sulfide is applied, if the pH of the second leaching solution is excessively low (less than 2), the precipitation of zinc is likely to be insufficient; on the other hand, if it is higher than 6, the amount of manganese precipitated increases, leading to a significant reduction in the amount of manganese that can be recovered, manganese loss proceeds, and the manganese yield is likely to decrease. From this perspective, the pH of the second leaching solution in the sulfide precipitation treatment process is preferably 2 or higher, more preferably 3 or higher, preferably 6 or lower, more preferably 5 or lower, and even more preferably less than 5. The pH of the second leaching solution is preferably pH 2 or higher and 6 or lower, more preferably pH 2 or higher and 5 or lower, even more preferably pH 3 or higher and 5 or lower, and even more preferably pH 3 or higher and less than 5.

[0172] Next, in the zinc removal process of sequence (A), the mixture obtained from the aforementioned sulfide precipitation treatment process is separated into a third solution and a zinc-containing precipitate to remove the zinc component.

[0173] More specifically, a third solution containing manganese ions and iron ions obtained from a sulfide precipitation treatment process is separated from a zinc-containing precipitate in which the remaining zinc sulfide is precipitated. Accordingly, the zinc component can be easily separated from the mixture after the sulfide precipitation treatment process, thereby obtaining a third solution containing manganese ions and iron ions. The separation means is not particularly limited and may follow the solid-liquid separation process described above. If the generated zinc-containing precipitate is large or fine, co-precipitation of manganese may occur, or troubles such as clogging of the filter cloth may easily occur during zinc separation. However, in the present invention, since the manganese component is retained while most of the zinc component in the separated particles is removed in advance during the acid / oxidizing agent treatment process, co-precipitation of manganese can be effectively avoided, thereby increasing the final manganese yield. Furthermore, by suppressing the amount and fineness of the zinc-containing precipitate, the zinc separation process can be performed simply and efficiently.

[0174] In addition, in the above-described sulfide precipitation treatment, some of the iron may be precipitated and removed from the solution. In this case, if the iron is removed to a concentration below a preset iron concentration, it is conceivable to end the treatment at this stage. However, in step (A), in order to obtain high-purity manganese by further separating and removing iron components, the iron removal process described below is additionally performed.

[0175] Iron removal process (sequence A)

[0176] In step (A), following the zinc removal process described above, an iron removal process is carried out. In the iron removal process in step (A), first, an oxidation treatment process is performed on a third solution containing manganese ions and iron ions obtained from the preceding zinc removal process, and the iron ions in the third solution are converted into an iron-containing precipitate, thereby enabling the separation and removal of iron components. Through this treatment, a mixture of a fourth solution (manganese-containing solution) containing manganese ions in high purity and an iron-containing precipitate is obtained from the third solution.

[0177] As for the oxidation treatment method, it is acceptable to use the oxidation treatment method described in step (B) below, which includes a suitable pH for the third solution. Here, the fact that the iron components in the third solution cannot be completely separated and removed when air aeration is performed under practical conditions on the third solution obtained through the sulfide precipitation treatment process is that the sulfide added during the sulfide precipitation treatment process acts as a reducing agent in this process. It is believed that this is because the oxygen supplied by the air aeration is consumed by this reducing agent, and depending on the amount of air aeration, the amount of oxygen becomes insufficient, leaving residual iron components that cannot be separated and removed in the solution after treatment. Furthermore, if air aeration is continued, the sulfide becomes sulfate ions, and eventually, the solution becomes an oxidizing atmosphere, causing the iron components to precipitate. However, this method is not practical because the aeration time becomes long.

[0178] Therefore, in the oxidation treatment process of sequence (A), it is desirable to add an additional oxidizing agent as a final oxidation treatment after air aeration. It is desirable to adjust the amount of oxidizing agent added so that the oxidation-reduction potential (vs. SHE) is 550 mV or higher by measuring the oxidation-reduction potential. Suitable examples of oxidizing agents include hydrogen peroxide and potassium permanganate.

[0179] In addition, if an oxidation treatment process is performed after the zinc removal process and after being left for an appropriate period, the iron component can be sufficiently precipitated by air aeration alone without the need for a final oxidation treatment. This is thought to be due to the fact that hydrogen sulfide, a reducing substance in the third solution generated during the preceding sulfide precipitation treatment process, is released into the air, making the third solution more susceptible to oxidation—that is, making it easier for the redox potential to rise. The appropriate period mentioned here cannot be stated uniformly as it varies depending on the storage conditions, such as whether it is a closed or open system, but it is estimated to be from a few days to about one week.

[0180] And, in the iron removal process of sequence (A), the mixture obtained from the aforementioned oxidation treatment process is separated into a fourth solution and an iron-containing precipitate to remove the iron component. In this way, a high-purity manganese-containing solution (fourth solution) can be recovered.

[0181] The separation means is not particularly limited and may follow the aforementioned high-value separation process.

[0182] Iron removal process (sequence B)

[0183] Next, in the iron removal process of sequence (B), an oxidation treatment is first performed on the second leaching solution obtained from the solid-liquid separation process. In this oxidation treatment, the second leaching solution is oxidized to precipitate iron ions among the ions contained in the second leaching solution as iron-containing precipitates, thereby enabling the removal of iron components from the second leaching solution. Through this treatment, a mixture of a third solution containing manganese ions and zinc ions and iron-containing precipitates is obtained from the second leaching solution.

[0184] As for the oxidation treatment method, commercial oxidation treatment methods may be applied, but in this embodiment, air aeration alone, which is a low-cost oxidation treatment method, is sufficient. From an economic perspective, it is preferable to use normal practical conditions for air aeration (air intake amount: (0.1 times to 1 times the amount of leachate) / min, aeration time: 15 to 60 minutes). In addition, as a final oxidation, a treatment involving the addition of an oxidizing agent may be added.

[0185] In addition, it is preferable to perform the oxidation treatment by adjusting the pH of the second leaching solution using a pH adjusting agent. If the pH of the second leaching solution is excessively low, such as less than 3, it is difficult for the iron component to precipitate. On the other hand, if the pH of the second leaching solution is excessively high, such as exceeding 7, the manganese component is also likely to precipitate at the same time. For this reason, it is preferable to adjust the second leaching solution to a pH range of 3 to 7. More preferably, the second leaching solution has a pH of 5 or higher, more preferably a pH of 6 or lower, and even more preferably a pH of 5 to 6. Accordingly, it is possible to make the iron component from the second leaching solution capable of precipitating and separating it while suppressing the precipitation of manganese, and furthermore, a high-purity manganese-containing solution with low impurity content can be obtained in a high yield.

[0186] Next, in the iron removal process of sequence (B), the mixture obtained from the aforementioned oxidation treatment process is separated into a third solution containing manganese ions and zinc ions, and an iron-containing precipitate that may mainly contain iron hydroxide. Accordingly, the iron component can be easily separated and removed from the mixture after the oxidation treatment process, thereby obtaining a third solution containing manganese and zinc components.

[0187] The separation means is not particularly limited and may follow the aforementioned high-value separation process.

[0188] Zinc removal process (sequence B)

[0189] In step (B), a zinc removal process is carried out following the aforementioned iron removal process. In the zinc removal process in step (B), a sulfide is applied to the third solution obtained from the preceding iron removal process, and the zinc ions among the ions in the third solution are mainly precipitated as zinc sulfide, thereby enabling the removal of the remaining zinc components from the third solution. Through this treatment, a mixture of a fourth solution (manganese-containing solution) containing manganese ions in high purity and a zinc-containing precipitate is obtained from the third solution.

[0190] The third solution separated in the preceding iron removal process contains manganese ions and residual zinc ions, and when a sulfide is applied to the third solution, the zinc component is selectively precipitated as a sulfide according to the same mechanism as the sulfide precipitation treatment process of the aforementioned sequence (A). Furthermore, by adjusting the amount of added sulfide, the concentration of sulfide ions, and the pH of the third solution, the concentration of zinc ions in the third solution can be easily reduced to below the analytical limit (0.1 mg / L).

[0191] The type of sulfide and the suitable pH of the third solution may be in accordance with the type of sulfide suitable and the pH of the second leaching solution in the sulfide precipitation treatment of the aforementioned sequence (A). The pH of the third solution is particularly preferably pH: 4.

[0192] In addition, the amount of sulfide to be actuated is preferably 1.1 equivalents or more as sulfur relative to molten zinc, more preferably 2 equivalents or more, and preferably 5 equivalents or less. When the amount of sulfide to be actuated is less than 1.1 equivalents, the removal of zinc precipitates proceeds but is incomplete, and the final removal rate is not stable. When the amount of sulfide to be actuated is 2 equivalents or more, the removal of zinc precipitates becomes significant. In addition, when the amount of sulfide to be actuated exceeds 5 equivalents, the amount of sulfide to be actuated becomes excessive, and manganese may also be removed by precipitation.

[0193] And, in the zinc removal process of step (B), the mixture obtained from the aforementioned sulfide precipitation treatment process is separated into a fourth solution and a zinc-containing precipitate in which zinc sulfide is precipitated, thereby removing the zinc component. In this way, the remaining zinc component is also removed, and a high-purity solution containing only manganese components can be recovered easily and with high yield.

[0194] As described above, if the third solution contains a large amount of zinc ions, a large amount of fine zinc-containing precipitate is generated by the sulfide precipitation treatment process, which promotes the co-precipitation of manganese and tends to lower the final manganese yield. Furthermore, during the subsequent solid-liquid separation, the filter cloth and the like are prone to clogging, making the zinc separation process difficult. However, in the present invention, in the acid / oxidizing agent treatment process preceding the sulfide precipitation treatment process, most of the zinc components in the separated particles are removed in advance while the manganese components are retained, thereby effectively avoiding the co-precipitation of manganese and increasing the final manganese yield. Additionally, the quantity and quality of the zinc-containing precipitate can be controlled, allowing the zinc separation process to be performed simply and efficiently.

[0195] The separation means is not particularly limited and may follow the aforementioned high-value separation process.

[0196] By sequentially passing through each of the above processes, carbon, zinc, and iron components other than manganese components contained in waste batteries can be almost completely separated and removed, allowing for the recovery of a high-purity manganese-containing solution with high yield, in which zinc and iron components are reduced to levels below the analytical limit.

[0197] In addition, the obtained manganese-containing solution may be used for various purposes as a high-purity manganese hydroxide by, for example, alkaline precipitation. In addition, the obtained manganese-containing solution may be used as a material for secondary battery electrodes by mixing it with other metals such as nickel (Ni) and then performing alkaline precipitation treatment.

[0198] (Manganese recovery facility)

[0199] Next, the manganese recovery facility of the present invention will be described. The recovery facility of the present invention is equipped with, in order, a sorting device, a crushing device, a sieving device, an acid / oxidizing agent treatment tank, a first solid-liquid separation device, an acid / reducing agent treatment tank, a second solid-liquid separation device, and a manganese extraction device group, and has the same features and effects as the manganese recovery method of the present invention. In addition, the manganese extraction device group includes a predetermined zinc removal device group and an iron removal device group in no particular order.

[0200] In addition, the manganese recovery facility of the present invention can be suitably used, for example, when carrying out the manganese recovery method of the present invention.

[0201] Configuration A

[0202] As one aspect of the recovery facility of the present invention, a configuration (A) capable of suitably implementing the aforementioned sequence (A) is shown in FIG. 7. As schematically shown in FIG. 7, the recovery facility may be equipped with a sorting device (10), a crushing device (20a), a sieve device (20b), an acid / oxidizing agent treatment tank (30), a first solid-liquid separation device (40), an acid / reducing agent treatment tank (50), a second solid-liquid separation device (60), a sulfide precipitation treatment tank (70), a zinc separation device (80), an oxidation treatment tank (90), an iron separation device (100), and a manganese-containing solution recovery tank (150) in this order from upstream to downstream. Here, the sulfide precipitation treatment tank (70) and the zinc separation device (80) constitute a zinc removal device group, and the oxidation treatment tank (90) and the iron separation device (100) constitute an iron removal device group. Additionally, the zinc removal device group and the iron removal device group constitute a manganese extraction device group.

[0203] In the sorting device (10), one or both of the manganese batteries and alkaline manganese batteries are sorted from the waste batteries. The type of sorting device is not specifically limited, and a device that distinguishes using shape or radiation, etc., can be suitably exemplified. In addition, the sorting of waste batteries may be performed manually.

[0204] The crushing device (20a) can be any conventional crusher, but it is preferable to use a two-axis rotary crusher.

[0205] It is preferable that the sieve device (20b) be equipped with a sieve having a mesh spacing of 1 mm or more and 20 mm or less. The mesh spacing of the sieve device (20b) is generally preferably 1 mm or more, preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 3 mm or less, for the same reasons as previously stated regarding the manganese recovery method.

[0206] The acid / oxidizing agent treatment tank (30) and the acid / reducing agent treatment tank (50) are preferably general stirring tanks equipped with a stirrer in the tank to carry out the leaching reaction by mixing the powder, the acid solution, and the oxidizing agent, and the first leaching residue, the acid solution, and the reducing agent, respectively. When using a gas such as oxygen and ozone as the oxidizing agent, it is preferable to additionally provide an aeration facility to circulate the oxidizing agent within the tank.

[0207] The sulfide precipitation treatment tank (70) is preferably a general stirring tank equipped with a stirrer in the tank to perform sulfide treatment by applying sulfide to the second leaching solution. Additionally, it is preferable to further provide a pH adjustment device capable of adjusting the pH of the second leaching solution by adding a pH adjusting agent.

[0208] In addition, the oxidation treatment tank (90) is preferably a general stirring tank equipped with a stirrer in the tank to perform oxidation treatment on the third solution. In addition, it is preferable to further provide a pH adjustment device capable of adjusting the pH of the third solution by adding a pH adjusting agent.

[0209] The first solid-liquid separation device (40), the second solid-liquid separation device (60), the zinc separation device (80), and the iron separation device (100) may all utilize devices selected from, for example, gravity sedimentation separation devices, filtration devices, centrifugal separation devices, filter press devices, membrane separation devices, etc. Additionally, it is preferable that each separation device be equipped with a recovery tank (110, 120, 130, 140) capable of recovering solid-liquid separated sediment, etc.

[0210] It is preferable that the manganese-containing solution recovery tank (150) be configured to be a tank capable of recovering the manganese-containing solution (4th solution) separated from solids in the iron separation device (100), storing it, and freely discharging it.

[0211] Configuration B

[0212] In addition, as another aspect of the recovery facility of the present invention, a configuration (B) capable of suitably implementing the aforementioned sequence (B) is shown in FIG. 8. As schematically shown in FIG. 8, the recovery facility may be equipped with a sorting device (10), a crushing device (20a), a sieve device (20b), an acid / oxidizing agent treatment tank (30), a first solid-liquid separation device (40), an acid / reducing agent treatment device (50), a second solid-liquid separation device (60), an oxidation treatment tank (71), an iron separation device (81), a sulfide precipitation treatment tank (91), a zinc separation device (101), and a manganese-containing solution recovery tank (150) in this order from upstream to downstream. Here, the oxidation treatment tank (71) and the iron separation device (81) constitute an iron removal device group, and the sulfide precipitation treatment tank (91) and the zinc separation device (101) constitute a zinc removal device group. Additionally, the iron removal device group and the zinc removal device group constitute a manganese extraction device group.

[0213] Here, the sorting device (10), crushing device (20a), sieving device (20b), acid / oxidizing agent treatment tank (30), first solid-liquid separation device (40), acid / reducing agent treatment tank (50), second solid-liquid separation device (60), iron separation device (81), zinc separation device (101), recovery tank (110, 120, 130, 140), and manganese-containing solution recovery tank (150) are all as described above for configuration A.

[0214] The oxidation treatment tank (71) is preferably a general stirring tank equipped with a stirrer in the tank to perform oxidation treatment on the second leaching solution. Additionally, it is preferable to further provide a pH adjustment device capable of adjusting the pH of the second leaching solution by adding a pH adjusting agent.

[0215] In addition, the sulfide precipitation treatment tank (91) is preferably a general stirring tank equipped with a stirrer in the tank to perform sulfide precipitation treatment in which the sulfide acts on the third solution. In addition, it is preferable to further provide a pH adjustment device capable of adjusting the pH of the third solution by adding a pH adjusting agent.

[0216] In addition, in the present invention, the structure, etc., of the various devices, reaction tanks, and recovery tanks constituting the recovery facility is not considered as long as they possess the respective functions described above.

[0217] Examples

[0218] The present invention will be further described below based on examples. Furthermore, the following examples represent suitable illustrative examples of the present invention and do not limit the invention in any way. Additionally, the following examples may be implemented with modifications within a scope suitable for the spirit of the present invention, and such modifications are also included within the technical scope of the present invention.

[0219] (Example 1)

[0220] Production of granules

[0221] A sorting process for separating manganese batteries and alkaline manganese batteries from waste batteries, and a crushing and sieving process for crushing the sorted waste batteries and sieving them through a sieve with a mesh size of 2.8 mm to obtain waste battery granules were performed to obtain waste battery granules. The main chemical components of the obtained granules (before the acid and oxidizing agent treatment process) are shown in Table 1. In addition, the obtained granules contain oxygen derived from oxides or hydroxides, a small amount of hydrogen, and moisture, in addition to the elements shown in Table 1.

[0222] Here, since the results of the chemical composition of the powder before the acid-oxidizing agent treatment process were the same in Experiment (A) and Example 1, both results are listed together in Table 1.

[0223] Acid and Oxidizing Agent Treatment Process

[0224] The obtained powder was introduced into an acid and oxidizing agent treatment tank (30) and an acid and oxidizing agent treatment process was carried out. In the acid and oxidizing agent treatment process, 300 mL of acid solution and 80 mL of sodium hypochlorite solution as an oxidizing agent were mixed with 30 g of powder to leach mainly zinc components from the powder. The acid concentration of the acid solution was set to sulfuric acid concentration: 2N (approx. 8.7 mass%). In addition, the acid leaching treatment time was set to 1 hour, and the acid leaching treatment was performed by stirring. In this case, the solid-liquid ratio, which is the ratio of powder to acid solution, was 100 g / L, and the amount of oxidizing agent added was 26.7 mass% of the amount of acid solution added.

[0225] 1st solid-liquid separation process

[0226] After the acid and oxidizing agent treatment process, the mixture of the first leaching liquid and the first leaching residue obtained was loaded into the first solid-liquid separation device (40) and separated by filtering with a pore size of 1 μm. The manganese concentration, zinc concentration, and iron concentration (mass%) in the obtained first leaching residue were quantified by ICP emission analysis. The yield of manganese from the powder to the first leaching residue was high at 99.99%. The results are shown in Table 1.

[0227] Here, since the results of the chemical composition in the first leaching residue after the acid-oxidizing agent treatment process were identical in the aforementioned experiment (A) and Example 1, both results are listed together in Table 1.

[0228] Acid and reducing agent treatment process

[0229] The first leaching residue obtained from the first solid-liquid separation process, 2N (approx. 8.7 mass%) sulfuric acid as an acid solution, and 30% hydrogen peroxide as a reducing agent were introduced into an acid-reducing agent treatment tank (50), and stirring treatment was performed for 1 hour. The solid-liquid ratio (first leaching residue / acid solution) was set to 50 g / L.

[0230] Second high-liquid separation process

[0231] The mixture of the obtained second leaching solution and the second leaching residue was loaded into a second solid-liquid separation device (60) and separated by filtering with a filter paper having a pore size of 1 μm. The manganese concentration, zinc concentration, and iron concentration (mg / L) in the second leaching solution obtained after the second solid-liquid separation process were quantified by ICP emission analysis. The obtained results are shown as "second leaching solution after the second solid-liquid separation process" in Table 2.

[0232] Preparation of the third solution (zinc removal process)

[0233] Next, the second leaching solution obtained by the second solid-liquid separation process was loaded into a sulfide precipitation treatment tank (70), and a sulfide precipitation treatment process was performed to react the sulfide with the zinc component still remaining in the second leaching solution. In the sulfide precipitation treatment process, sodium hydrosulfide was added to the second leaching solution as a sulfide in an amount of 2 equivalents as sulfur relative to the dissolved zinc. In addition, sodium hydrosulfide was added in the form of a solution dissolved in distilled water. In addition, the pH of the second leaching solution during the sulfide precipitation treatment was adjusted to 4 using a pH adjusting solution (3M sulfuric acid or 100g / L sodium hydroxide). In addition, the treatment time for the sulfide precipitation treatment was set to 30 minutes and the treatment was performed by stirring.

[0234] The mixture after the above-described sulfide precipitation treatment process was loaded into a zinc separation device (80), and a zinc separation process was performed to separate solids and liquids by suction filtration with a filter paper having a pore size of 1 μm, thereby separating it into a third solution and a zinc-containing precipitate. Here, the filtration time, which took about 35 minutes in a conventional zinc separation process, was shortened to about 15 minutes in the zinc separation process of this embodiment, in which an acid / oxidizing agent treatment process was performed on the separated particles beforehand. Then, the components of the obtained third solution were quantitatively analyzed by ICP emission analysis. In addition, the amounts of sodium hydrosulfide solution and pH adjuster added were recorded, and the effect of dilution by these solutions was corrected from the analysis values. The obtained results are listed together as "third solution after zinc removal process" in Table 2.

[0235] Preparation of the 4th solution (iron removal process)

[0236] Next, the third solution obtained through the zinc removal process was loaded into an oxidation treatment tank (90) and an oxidation treatment process was performed to carry out an oxidation reaction. In the oxidation treatment process, as an oxidation treatment, air aeration was first performed on the obtained third solution. The air aeration conditions were set as: blowing amount: (volume equal to the amount of the third solution) / min, and aeration time: 30 minutes. After air aeration, the components contained in the intermediate solution, which was filtered by suction with a pore size of 1 μm filter paper, were quantitatively analyzed using the above method. The obtained results are listed together as "Intermediate Solution after Oxidation Treatment" in Table 2.

[0237] Next, as a further oxidation treatment, a direct oxidizing agent was added to the third solution after the air aeration. When adding the oxidizing agent, a pH adjusting solution (3M sulfuric acid or 100g / L sodium hydroxide) was added to adjust the pH of the third solution to 5, and then about 8 to 16 mL of hydrogen peroxide was added as the oxidizing agent so that the redox potential was 550 mV or higher. In this way, the iron component in the third solution was precipitated as iron hydroxide and made removable. In addition, the treatment time with the oxidizing agent was set to 30 minutes.

[0238] The mixture after the oxidation treatment process by air aeration and the addition of an oxidizing agent was loaded into an iron separation device (100), and the mixture was filtered by suction with a filter paper with a pore size of 1 μm to perform an iron separation process in which the solid and liquid were separated into a manganese-containing solution (4th solution) and an iron-containing precipitate.

[0239] For the obtained fourth solution, the components contained therein were quantitatively analyzed using the above method. In addition, the amounts of hydrogen peroxide and pH adjuster added were recorded, and the effect of dilution by these solutions was corrected from the analysis values. The obtained results are listed together in Table 2 as "Fourth Solution after Iron Removal Process." The yield of manganese in the obtained fourth solution (manganese ion-containing solution) was 99%.

[0240]

[0241] From Table 2, it can be seen that according to Step A, which is one embodiment of the manganese recovery method of the present invention, zinc and iron components other than the manganese component contained in the waste battery can be easily separated and removed to an analysis limit (0.1 mg / L) or less. Thus, according to the present invention, it can be seen that the manganese component contained in the waste battery can be recovered easily, efficiently, and with a high yield using a high-purity manganese ion-containing solution.

[0242] (Example 2)

[0243] A powder was prepared in the same manner as in Example 1, and a powder with the composition shown in Table 1 was obtained. In addition, as in Example 1, an acid / oxidizing agent treatment process, a first solid-liquid separation process, an acid / reducing agent treatment process, and a second solid-liquid separation process were performed, and as a result, the content (mg / L) of each component of manganese, zinc, and iron in the second leaching solution after the second solid-liquid separation process was as shown in Table 3.

[0244] Next, as in Example 1, the preparation of the third solution (zinc removal process) was carried out, and the components of the third solution after the zinc removal process were as shown in Table 3. In addition, the filtration time, which took about 35 minutes in the conventional zinc separation process, was shortened to about 25 minutes in the zinc separation process of this example, in which an acid and oxidizing agent treatment process was performed on the separated particles beforehand.

[0245] Next, the third solution obtained through the zinc separation process was left at room temperature for one week, then loaded into an oxidation treatment tank (90) and subjected to an oxidation treatment process to perform an oxidation reaction. In the oxidation treatment process, only air aeration was performed as an oxidation treatment on the third solution after leaving it. The conditions for air aeration were set as: blowing amount: (volume equal to the amount of the third solution) / min, and aeration time: 30 minutes. After performing air aeration, the manganese-containing solution (fourth solution) that was suction-filtered with a pore size of 1 μm was quantitatively analyzed for the contained components using the above method. The results obtained are listed together as "Fourth solution after iron removal process" in Table 3. The yield of manganese in the obtained fourth solution (manganese ion-containing solution) exceeded 99%.

[0246]

[0247] From Table 3, it can be seen that in Step A, which is an embodiment of the manganese recovery method of the present invention, if an oxidation treatment process is performed on the third solution separated by sulfide precipitation treatment after allowing it to stand for an appropriate period, the iron component can be sufficiently separated and removed as a precipitate even with oxidation treatment by air aeration alone. As a result, the manganese component could be recovered with a high yield.

[0248] (Example 3)

[0249] A powder was prepared in the same manner as in Example 1, and a powder with the composition shown in Table 1 was obtained. In addition, an acid / oxidizing agent treatment process, a first solid-liquid separation process, an acid / reducing agent treatment process, and a second solid-liquid separation process were performed in the same manner as in Example 1. As a result, the content (mg / L) of each component of manganese, zinc, and iron in the second leaching solution after the second solid-liquid separation process was as shown in Table 4.

[0250] Preparation of the third solution (iron removal process)

[0251] Next, an oxidation treatment process was performed on the second leachate separated in the second solid-liquid separation process. In the oxidation treatment process, air aeration was performed on the obtained second leachate to generate iron hydroxide from the iron components contained in the second leachate and to make it possible to separate and remove the iron components from the second leachate as iron-containing precipitates. The conditions for air aeration were set as: blowing rate: (volume mL equal to the volume of the second leachate) / min, and aeration time: 30 minutes. In addition, when performing the oxidation treatment, the pH of the second leachate was adjusted to 5 using a pH adjusting agent (3M sulfuric acid or 100g / L sodium hydroxide).

[0252] After oxidation treatment, the third solution and the iron-containing precipitate were separated into the third solution and the iron-containing precipitate by suction filtration using a filter paper with a pore size of 1 μm (iron separation process). Then, the components (manganese, zinc, and iron) contained in the third solution obtained from the iron removal process were quantitatively analyzed by ICP emission analysis. In addition, the amount of pH adjuster added was recorded, and the effect of dilution by the pH adjuster on the measured values ​​was corrected. The concentrations (mg / L) of each component of manganese, zinc, and iron in the obtained third solution are listed together as "Third Solution after Iron Removal Process" in Table 4.

[0253] Preparation of Solution 4 (Zinc Removal Process)

[0254] Next, a sulfide precipitation treatment process was carried out by reacting a sulfide with the third solution separated in the iron separation process, primarily to precipitate the zinc ions still remaining in the third solution as zinc sulfide (zinc-containing precipitate) so that they could be separated and removed from the third solution. The sulfide used was sodium hydrosulfide, and it was added in an amount of 2 equivalents as sulfur relative to the dissolved zinc. In addition, sodium hydrosulfide was added in the form of a solution dissolved in distilled water. Furthermore, the pH of the third solution during the sulfide precipitation treatment was adjusted to 4 using a pH adjusting solution (3M sulfuric acid or 100g / L sodium hydroxide). In addition, the treatment time for the sulfide precipitation treatment was set to 30 minutes and the treatment was performed with stirring.

[0255] The mixture after the sulfide precipitation treatment was separated into a manganese-containing solution (Solution 4) and a zinc-containing precipitate by suction filtration using a filter paper with a pore size of 1 μm (zinc separation process). The filtration time, which took about 35 minutes in a conventional zinc separation process, was shortened to about 25 minutes in the zinc separation process of this example, in which an acid and oxidizing agent treatment process was performed on the separated particles beforehand. Then, the components of the Solution 4 obtained after separation were quantitatively analyzed by ICP emission analysis. In addition, the amounts of sodium hydrosulfide solution and pH adjuster added were recorded, and the effect of dilution by these solutions was corrected from the measured values. The obtained results are listed together as "Solution 4 after zinc removal process" in Table 4. The yield of manganese in the obtained Solution 4 (manganese ion-containing solution) was 95%.

[0256]

[0257] From Table 4, it can be seen that according to Step B, which is an embodiment of the manganese recovery method of the present invention, zinc and iron components other than manganese components contained in waste batteries can be easily separated and removed to an analysis limit (0.1 mg / L) or less. Thus, according to the present invention, manganese components contained in waste batteries can be recovered easily and efficiently, and with a high yield, using a high-purity manganese ion-containing solution.

[0258] (Example 4)

[0259] The production of the powder was carried out in the same manner as in Example 1. The obtained powder was introduced into an acid-oxidizing agent treatment tank (30), and the amount of sodium hypochlorite added as an oxidizing agent was varied during the acid-oxidizing agent treatment process. Specifically, 300 mL of acid solution and 0 to 200 mL of sodium hypochlorite solution were mixed with 30 g of the powder, and the zinc component was mainly leached from the powder. Other conditions were the same as in Example 1. In this case, the solid-liquid ratio of the powder to the acid solution was 100 g / L, and the amount of oxidizing agent added was 0 to 66.7 mass% of the amount of acid solution added.

[0260] Next, the mixture of the obtained first leaching solution and the first leaching residue was loaded into a first solid-liquid separation device (40) and separated into solid and liquid by filtering with a filter paper having a pore size of 1 μm. The manganese concentration and zinc concentration (mg / L) in the obtained first leaching solution were quantified by ICP emission analysis. The results are shown in FIG. 9.

[0261] It was found that by adding 60 mL (20 mass% relative to the amount of acid solution added) or more of the sodium hypochlorite solution, the amount of manganese dissolved in the first leaching solution could be significantly reduced to about 1 / 5 compared to the case where no sodium hypochlorite solution was added (0 mass% relative to the amount of acid solution added). In addition, it was found that by adding 150 mL (50 mass% relative to the amount of acid solution added) or more of the sodium hypochlorite solution, the amount of manganese dissolved in the first leaching solution could be suppressed to less than 1 mg / L, making it possible to increase the yield of manganese components from the powder to the first leaching residue to 99.99%. Meanwhile, as shown in Fig. 9, zinc was dissolved in the first leaching solution at a concentration of about 20,000 mg / L regardless of the amount of sodium hypochlorite solution added. Accordingly, it was found that it is desirable to control the amount of sodium hypochlorite solution added as an oxidizing agent to 60 mL (20 mass% relative to the amount of acid solution added) or more, and more desirable to control it to 150 mL (50 mass% relative to the amount of acid solution added), and accordingly, it is possible to selectively remove zinc components while securing manganese components in the first leaching residue in high yield, and thus recover manganese components in high yield. Explanation of the symbols

[0262] 10: Sorting device 20a: Crushing device 20b: Sieve separation device 30: Acid and Oxidizing Agent Treatment Tank 40: First solid-liquid separation device 50: Acid-reducing agent treatment tank 60: Second high-liquid separation device 70: Sulfide precipitation treatment tank (Composition A) 71: Oxidation treatment tank (Component B) 80: Zinc separator (Configuration A) 81: Iron separator (Component B) 90: Oxidation treatment tank (Component A) 91: Sulfide precipitation treatment tank (Composition B) 100: Iron separator (Component A) 101: Zinc separator (Component B) 110: Recovery Team 120: Recovery Team 130: Recovery Team 140: Recovery Team 150: Manganese-containing solution recovery tank

Claims

Claim 1 A sorting process for sorting one or both of manganese batteries and alkaline manganese batteries from waste batteries; a crushing and sieving process for crushing and sieving one or both of the manganese batteries and alkaline manganese batteries sorted in the sorting process to obtain a powdered body; an acid and oxidizing agent treatment process for mixing an acid solution and an oxidizing agent with the powdered body obtained in the crushing and sieving process to obtain a first leaching liquid and a first leaching residue; a first solid-liquid separation process for separating the first leaching liquid and the first leaching residue obtained in the acid and oxidizing agent treatment process; an acid and reducing agent treatment process for mixing an acid solution and a reducing agent with the first leaching residue separated in the first solid-liquid separation process to obtain a second leaching liquid and a second leaching residue; a second solid-liquid separation process for separating the second leaching liquid and the second leaching residue obtained in the acid and reducing agent treatment process; and the second A method for recovering manganese contained in waste batteries, wherein the manganese extraction process is carried out in this order to remove zinc ions and iron ions from among zinc ions, iron ions, and manganese ions contained in the second leaching solution, and to obtain a solution containing manganese ions, wherein the manganese extraction process comprises: a zinc removal process including a sulfide precipitation treatment process in which a sulfide is applied to the zinc ions to precipitate the zinc ions, and additionally, a zinc separation process for separating the obtained zinc-containing precipitate; and an iron removal process including an oxidation treatment process in which the iron ions are oxidized to precipitate the iron ions, and additionally, an iron separation process for separating the obtained iron-containing precipitate; in no particular order. Claim 2 A recovery method according to claim 1, wherein the oxidizing agent in the acid-oxidizing agent treatment process is any one of sodium hypochlorite solution, oxygen, ozone, and potassium permanganate solution. Claim 3 A recovery method according to claim 1 or 2, wherein the acid solution in the acid / oxidizing agent treatment process is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. Claim 4 A recovery method according to claim 1 or 2, wherein the solid-liquid ratio of the separated powder and the acid solution in the acid-oxidizing agent treatment process is 50 g / L or more. Claim 5 A recovery method according to claim 1 or 2, wherein the acid solution in the acid-reducing agent treatment process is a dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less, or a dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. Claim 6 A recovery method according to claim 1 or 2, wherein the reducing agent in the acid-reducing agent treatment process is any one of hydrogen peroxide, sodium sulfide, sodium bisulfite, sodium thiosulfate, and iron sulfate. Claim 7 A recovery method according to claim 1 or 2, wherein the manganese extraction process is performed in the order of the zinc removal process and then the iron removal process, wherein in the zinc removal process, a sulfide precipitation treatment process is performed to precipitate zinc ions in the second leaching solution by reacting a sulfide with the second leaching solution, and then a zinc separation process is performed to separate the obtained zinc-containing precipitate from a third solution containing manganese ions and iron ions from the solid-liquid phase, and in the iron removal process, an oxidation treatment process is performed to oxidize the third solution obtained in the zinc removal process to precipitate iron ions in the third solution, and then an iron separation process is performed to separate the obtained iron-containing precipitate from a fourth solution containing manganese ions from the solid-liquid phase. Claim 8 In claim 7, a recovery method in which, in the sulfide precipitation treatment process, the second leaching solution is adjusted to a pH of 2 or higher and 6 or lower. Claim 9 A recovery method according to claim 7, wherein in the oxidation treatment process, air aeration is performed on a third solution containing manganese ions and iron ions, or additionally an oxidizing agent is added to the third solution, and the pH of the third solution is adjusted to 3 or higher and 7 or lower. Claim 10 A recovery method according to claim 1 or 2, wherein the manganese extraction process is performed in the order of the iron removal process and then the zinc removal process, wherein in the iron removal process, an oxidation treatment process is performed to oxidize the second leaching solution and precipitate the iron ions in the second leaching solution, and then an iron separation process is performed to separate the obtained iron-containing precipitate from a third solution containing manganese ions and zinc ions from the solid-liquid phase, and in the zinc removal process, a sulfide precipitation treatment process is performed to react the third solution obtained in the iron removal process with a sulfide to precipitate the zinc ions in the third solution, and then a zinc separation process is performed to separate the obtained zinc-containing precipitate from a fourth solution containing manganese ions from the solid-liquid phase. Claim 11 In claim 10, a recovery method in which, in the above-mentioned sulfide precipitation treatment process, a third solution containing manganese ions and zinc ions is adjusted to a pH of 2 or higher and 6 or lower. Claim 12 A recovery method according to claim 10, wherein in the oxidation treatment process above, air aeration is performed on the second leachate, and the pH of the second leachate is adjusted to 3 or higher and 7 or lower. Claim 13 A recovery method according to claim 1 or 2, wherein the sulfide used in the sulfide precipitation treatment process is any one of sodium hydrosulfide, sodium sulfide, and hydrogen sulfide. Claim 14 A sorting device for sorting one or both of manganese batteries and alkaline manganese batteries from waste batteries; a crushing device for loading one or both of the manganese batteries and alkaline manganese batteries sorted by the sorting device and performing crushing treatment to obtain a crushed product; a sieving device for performing sieving treatment on the crushed product obtained by the crushing device to obtain a separated product; an acid-oxidizing agent treatment tank for applying an acid solution and an oxidizing agent to the separated product obtained by the sieving device; a first solid-liquid separation device for separating a first leaching liquid and a first leaching residue obtained from the acid-oxidizing agent treatment tank; an acid-reducing agent treatment tank for applying an acid solution and a reducing agent to the first leaching residue separated by the first solid-liquid separation device; a second solid-liquid separation device for separating a second leaching liquid and a second leaching residue obtained from the acid-reducing agent treatment tank; and zinc ions, iron ions, and manganese ions contained in the second leaching liquid from the second leaching liquid separated by the second solid-liquid separation device A recovery facility for manganese contained in waste batteries, comprising, in this order, a group of manganese extraction devices for removing zinc ions and iron ions and obtaining a solution containing manganese ions, wherein the group of manganese extraction devices comprises a zinc removal device group including a sulfide precipitation treatment tank for precipitating zinc ions by reacting a sulfide with the zinc ions and additionally, a zinc separation device for separating solid and liquid from the obtained zinc-containing precipitate; and an iron removal device group including an oxidation treatment tank for precipitating iron ions by oxidizing the iron ions and additionally, an iron separation device for separating solid and liquid from the obtained iron-containing precipitate; in no particular order.

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