JP7107473B1 - Method and equipment for recovering manganese from waste dry batteries - Google Patents

Abstract

Provided is a method for recovering manganese from waste dry batteries, capable of simply recovering a highly pure manganese-containing solution. The present invention comprises a step of sorting waste dry batteries; a crushing and sieving step of obtaining powders from the waste dry batteries; an acid treatment step of the powders; and a first solid-liquid separation for separating a first leaching residue. an acid/reducing agent treatment step of obtaining a second leachate from the first leach residue; a second solid-liquid separation step of separating the second leachate; and manganese to obtain a manganese ion-containing solution from the second leachate. are performed in this order, and the manganese extraction step includes a predetermined zinc removal step and an iron removal step in random order.

Description

TECHNICAL FIELD The present invention relates to a method and equipment for recovering valuable metals from waste dry batteries. In particular, the present invention separates manganese, which is a major valuable component of waste dry batteries, after subjecting waste manganese dry batteries and/or alkaline manganese dry batteries to acid treatment as valuable metals, and separates manganese, which is a main valuable component of waste dry batteries, and has a high purity that can be used for various batteries. The present invention relates to a method and equipment for recovering manganese from waste dry batteries, which can be recovered as manganese.

In recent years, due to the depletion of metal resources and rising transaction prices, it has become necessary to actively recover valuable metals from low-grade ore, concentrates, by-products from steel mills, industrial waste, etc. . For example, manganese, which is one of the valuable metals, is regarded as an essential metal in a wide variety of industrial fields, and there is concern that the demand for manganese will exceed the reserves in the future. In particular, ironworks have conventionally consumed a large amount of manganese as a raw material for steelmaking, and securing manganese sources is an extremely important issue in the ironmaking field. Moreover, in recent years, the consumption of manganese for secondary batteries such as lithium ion batteries has increased, and securing a source of manganese has become a very serious problem in this secondary battery field as well.

On the other hand, in Japan, a huge amount of dry batteries are produced, consumed, disposed of and discarded as industrial waste. Some dry batteries discarded as industrial waste (waste dry batteries) have a high manganese content. For example, manganese dry batteries and alkaline manganese dry batteries, which are typical primary batteries, use manganese dioxide as a positive electrode material and zinc as a negative electrode material. Manganese dry batteries sometimes use zinc chloride as the electrolyte. In addition, iron is used for the outer cylinder of these dry batteries.

Therefore, there is a demand for a technique for recovering the manganese component from these waste dry batteries and reusing it as a raw material for steelmaking. From this point of view, recently, various techniques have been proposed for recovering not only zinc, iron and carbon, but also manganese from waste dry batteries.

For example, in Patent Document 1, manganese batteries and alkaline manganese batteries are sorted from waste dry batteries, crushed and sieved to obtain powders, and the obtained powders are dissolved in dilute hydrochloric acid or dilute sulfuric acid for acid treatment. A method for the recovery of metallurgical raw materials from waste dry batteries has been proposed in which the manganese dioxide and carbon-containing mixtures are separated and recovered. The manganese dioxide and carbon-containing mixture recovered by the technique described in Patent Document 1 can be used as a starting material for ferromanganese production or as a material directly used in a smelting furnace instead of ferromanganese.

Further, Patent Document 2 proposes a technique for separating and recovering manganese dioxide and zinc chloride from waste dry batteries. The technique described in Patent Document 2 is to obtain a material containing a large amount of manganese and zinc from waste dry batteries, wash this material with water, dissolve it in hydrochloric acid, remove insoluble matter (carbon powder, etc.), A mixed aqueous solution of manganese chloride and zinc chloride is prepared, the solution is purified to remove impurities, heated and concentrated, perchloric acid is added to the concentrate and heated to oxidize manganese chloride in the solution to manganese dioxide. After obtaining a solid mixture of manganese dioxide and zinc chloride, water is added to the obtained solid mixture to dissolve zinc chloride, followed by filtration to separate insoluble manganese dioxide and water-soluble zinc chloride. It is a technology to collect. In addition, in the technique described in Patent Document 2, the zinc chloride solution is dissolved in an organic solvent to obtain a purified product of zinc chloride. The point of the technology described in Patent Document 2 is to convert manganese chloride into manganese dioxide with a small amount of perchloric acid, and the manganese dioxide and zinc chloride obtained by the technology described in Patent Document 2 are new. It is said that it can be used for manufacturing manganese dry batteries.

In addition, in Patent Documents 3 to 5, an acid or an acid and a reducing agent are allowed to act on a manganese-containing granular material obtained by pulverizing and sieving waste dry batteries, and ozone is further allowed to act on the obtained manganese solution. A technique is described for recovering manganese, which is a valuable component, from waste dry batteries by precipitating only manganese as an oxide.

More specifically, Patent Document 3 proposes a method for recovering valuable components from waste dry batteries. In the technique described in Patent Document 3, there is a process of sorting out manganese dry batteries and/or alkaline manganese dry batteries from waste dry batteries, and a pulverization/sieving process of crushing and sieving the dry batteries sorted out in the sorting process to obtain granules. and an acid leaching step of mixing the powder obtained in the pulverization and sieving step, an acid solution, and a reducing agent to leach manganese and zinc from the powder, and a leach solution obtained in the acid leaching step. a first solid-liquid separation step for solid-liquid separation of the leachate and the leach residue; and ozone acting on the leachate separated in the first solid-liquid separation step to oxidize and precipitate manganese ions contained in the leachate, Through an ozonation step of obtaining a manganese-containing precipitate and a zinc ion-containing solution, and a second solid-liquid separation step of solid-liquid separation of the manganese-containing precipitate and the zinc ion-containing solution obtained in the ozonation step, sequentially , the manganese component contained in the waste dry battery is recovered as a manganese-containing precipitate. As a result, according to the technique described in Patent Document 3, it is possible to extract high-purity manganese containing extremely little zinc, carbon, or the like from waste dry batteries. In Patent Document 3, an alkali agent is added to a zinc ion-containing solution to perform an alkali precipitation treatment process in which the zinc ions in the zinc ion-containing solution are turned into zinc-containing precipitates, thereby removing the zinc component contained in the waste dry battery. are collecting.

Further, Patent Document 4 proposes a method for separating resources from waste dry batteries. In the technique described in Patent Document 4, there is a process of sorting manganese dry batteries and/or alkaline manganese dry batteries from waste dry batteries, and a pulverization/sieving process of crushing and sieving the dry batteries sorted in the sorting process to obtain granules. an acid leaching step of subjecting the granular material to an acid leaching treatment using an acid solution to obtain a leaching solution leached with manganese and zinc and a leaching residue containing manganese; and a leaching solution and leaching residue obtained in the acid leaching step. a first solid-liquid separation step for solid-liquid separation, and ozone is applied to the leachate separated in the first solid-liquid separation step to oxidize and precipitate the manganese ions contained in the leachate, thereby obtaining a manganese-containing precipitate. and a second solid-liquid separation step for solid-liquid separation of the manganese-containing precipitate obtained in the ozonation step and the zinc ion-containing solution. The manganese component contained in the waste dry battery is separated as a leached residue and a manganese-containing precipitate, and the zinc component contained in the waste dry battery is separated as a zinc ion-containing solution.

Patent Document 5 describes a method for producing high-grade manganese metal. In the technique described in Patent Document 5, an arc melting furnace is charged with a manganese-containing substance, a reducing agent, and a flux, and the manganese-containing substance is reduced by energization and/or reaction heat of the reducing agent, and metal A method for producing high-grade manganese metal, which is manganese. In the technique described in Patent Document 5, as a manganese-containing substance, manganese contained in waste dry batteries is subjected to an acid leaching treatment, and the resulting acid leached solution is subjected to an ozone treatment to precipitate only manganese as an oxide, followed by separation. A manganese-containing material obtained through treatment is used.

In Patent Documents 6 and 7, manganese is recovered by leaching manganese from metal oxides or metal hydroxides using bivalent iron obtained by acting iron-reducing bacteria on trivalent iron. technology is described.

More specifically, Patent Document 6 proposes the following metal recovery method. That is, the technique described in Patent Document 6 is to allow iron-reducing bacteria to act on a group consisting of metal oxides and metal hydroxides, reduce trivalent iron to divalent iron, and convert the resulting bivalent iron into is used to leach metals such as cobalt, nickel, and manganese included in the group consisting of metal oxides and metal hydroxides to produce a leachate and residue, separate the resulting leachate and residue, and obtain the desired It is a method of recovering metals. According to this technology, low-grade metals contained in metal oxides and metal hydroxides can be recovered at high speed and with high efficiency.

Further, Patent Document 7 proposes a manganese recovery method. In the technique described in Patent Document 7, a treatment liquid containing trivalent iron ions is mixed with an object to be treated containing manganese and iron-reducing bacteria to reduce the trivalent iron ions to divalent iron ions. a leaching step of leaching manganese ions from the object to be treated using valence iron ions as a reducing agent; a solid-liquid separation step of separating the obtained leaching solution into solids and liquids; and manganese contained in the separated liquid after the solid-liquid separation step. This technique includes an insolubilization step of oxidizing ions to make them insolubilized, and a step of separating and recovering the obtained manganese component by precipitation. As a result, manganese can be concentrated and recovered at a high concentration rate under relatively moderate conditions, and manganese can be recovered easily and inexpensively from a large amount of material to be treated.

JP 2007-012527 A JP-A-11-191439 WO2015/162902 JP 2015-206077 A JP 2016-156074 A Japanese Patent Application Laid-Open No. 2007-113116 JP 2014-5496 A

However, at present, the recovery of valuable metals from waste dry batteries such as discarded manganese dry batteries and alkaline manganese dry batteries is done by zinc refining manufacturers, or by some electric furnace manufacturers. However, it only recovers part of the iron and carbon contained in the waste batteries. Many of the valuable metals contained in waste dry batteries are not recovered and are sent to landfills or the like as waste materials. This is due to the fact that it is technically difficult to separate various valuable metals contained in waste dry batteries, and that there are still problems such as being economically disadvantageous.

In this regard, Patent Document 2 describes that recovered manganese can be used to manufacture new manganese dry batteries. However, the technique described in Patent Literature 2 has the problem that the procedure is complicated, and that it includes a step such as heating and concentrating that consumes a large amount of energy, which increases the production cost.
Furthermore, all of the manganese recovered from waste dry batteries by the techniques described in the above patent documents other than Patent Document 2 have a problem of low purity as a raw material for secondary battery electrode materials.

When the recovered manganese is used as a raw material for secondary battery electrode materials, its purity is required to be high. This is because the impurities mixed in the electrode material of the secondary battery have a significant effect on the performance of the secondary battery such as the discharge capacity and the repetition characteristics, and cause a significant deterioration in the performance of the secondary battery. . Furthermore, in recent years, it has been found that the presence of impurities mixed in the electrode material of a secondary battery can also cause ignition of the battery due to a short circuit. Therefore, it is required to strictly reduce impurities in manganese used as a raw material for electrode materials of secondary batteries.

However, with the conventional techniques described above, it is extremely difficult to recover manganese components from waste dry batteries easily, at low cost, and with high purity. Therefore, manganese in waste dry batteries has not been effectively recycled in the conventional technology.

The present invention has been made in view of the above-described problems of the prior art, and the manganese contained in waste dry batteries can be easily converted into a highly pure manganese-containing solution with extremely low contamination of impurities such as zinc, iron, and carbon. It is an object of the present invention to provide a recoverable method and equipment for recovering manganese from waste dry batteries.
The term "high-purity manganese-containing solution" as used here means that zinc (Zn) and iron (Fe) are present as impurities in the solution, both of which A manganese-containing solution that is below the analytical limit, eg, below 0.1 mg/L.

Manganese dry batteries and/or alkaline manganese dry batteries are sorted out from the waste dry batteries, crushed and sieved, and the materials constituting the dry battery are separated into solid matter on the sieve and powder particles under the sieve. Among the materials that make up the dry battery, mainly steel packaging materials, zinc cans, brass rods, paper materials, plastics, etc. are crushed into foil-like or flake-like solids and separated on a sieve. On the other hand, manganese dioxide, carbon, zinc chloride, ammonium chloride, caustic potash, and further MnO(OH), Zn(OH) ₂ , Mn(OH) ₂ , ZnO, etc. generated by electrical discharge become powders and particles, and are sieved. separated. In addition, usually, a very small amount of iron is inevitably mixed in the powder.

In order to achieve the above-described object, the present inventors diligently studied means for separating impurities that are effective for recovering manganese contained in waste dry batteries as a highly pure manganese-containing solution with few impurities. In particular, the present inventors sorted out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries, and further crushed and sieved them to obtain unintended components (impurities) from the granules obtained. , especially zinc, which is the second most abundant material after manganese, was thoroughly investigated.

As a result, the present inventors obtained a leachate in which iron and residual manganese and zinc were leached out by reacting an acid and a reducing agent on the granules, and then added sodium hydrosulfide NaHS or the like to the leachate. A sulfide precipitation treatment step in which zinc ions remaining in the leachate are first selectively precipitated as sulfides (zinc-containing sulfides) by the action of sulfides, and zinc separation in which the obtained zinc-containing precipitates are separated. It has been found that the zinc component can be further removed from the leachate by applying the steps of (1) and (2). The inventors have also found that the zinc ion concentration in the solution left after the zinc removal step can be easily reduced to less than the analytical limit of 0.1 mg/L.

However, since zinc is contained second only to manganese in granules, a large amount of zinc is dissolved in the leachate obtained by the above method. Here, when a sulfide such as sodium hydrosulfide is allowed to act on the leachate to precipitate zinc, a large amount of fine zinc sulfide precipitates as zinc-containing precipitates. It was newly found that this large amount of fine sediment easily clogs filter paper, filter cloth, etc., and the subsequent solid-liquid separation is difficult. Therefore, the present inventors considered that a pretreatment step is necessary to reduce the amount of zinc-containing precipitates as much as possible, that is, to remove a considerable amount of zinc in the granules prior to obtaining the leachate. .

As an example of the pretreatment process, the inventors of the present invention have attempted to heat the powder to about 1000° C. in an inert atmosphere to volatilize and remove zinc. However, it has been found that there is a risk that the zinc volatilized from the granules cools in the exhaust system and solidifies again, clogging the exhaust system. In order to avoid clogging, it was necessary to constantly heat the exhaust system to over 420°C, the melting point of zinc, and such a pretreatment process was considered uneconomical.

Next, as another example of the pretreatment process, the present inventors attempted an acid treatment process in which manganese and zinc are separated by utilizing the difference in acid solubility between manganese and zinc. The acid treatment step was performed by immersing the granules in 2N sulfuric acid (mass% concentration: about 8.7%) at 25°C for 1 hour. FIG. 4 shows the X-ray diffraction data of the granular material before the acid treatment process and the granular material (first leaching residue) separated after the acid treatment process. After the acid treatment step, the zinc oxide diffraction peak disappeared, while the manganese dioxide peak was newly detected. From this result, it is considered that zinc and manganese in the powder react with acid according to the following reaction formulas (1) and (2) in the acid treatment step.
ZnO + 2H ⁺ → Zn ²⁺ + H ₂ O (1)
_{ZnMn2O4 +} 4H ^+- > ^Zn2++ Mn2 ⁺⁺ MnO2 ₊ 2H2O ( ₂ )
From reaction formulas (1) and (2), it can be seen that zinc contained in the granules is easily dissolved in the acid treatment step, while manganese is only partially dissolved. That is, the present inventors have found that zinc contained in the granular material can be preferentially removed to the leachate (first leachate) in advance by subjecting the granular material to an acid treatment step as a pretreatment step.
Then, the present inventors further leached out iron and remaining manganese and zinc by allowing an acid and a reducing agent to act on the granules (first leaching residue) in which the amount of zinc was reduced by the acid treatment step. After obtaining the leachate (second leachate), if the remaining zinc component and iron component are selectively precipitated and separated from the second leachate according to a predetermined procedure, regardless of the order of the precipitation and separation steps, However, the inventors have found that a highly pure manganese solution can be obtained simply and inexpensively.

As procedure A, which is a more specific embodiment, the present inventors reacted the second leachate with a sulfide such as sodium hydrosulfide NaHS to sulfide the zinc ions still remaining in the second leachate. zinc component can be further removed from the second leachate by performing a sulfide precipitation treatment step of selectively precipitating as a substance (zinc-containing sulfide) and a zinc separation step of separating the obtained zinc-containing precipitate. It was found (zinc removal step in procedure A). The present inventors have also found that the zinc ion concentration in the solution (third solution) left after the zinc removal step can be easily reduced to less than the analytical limit of 0.1 mg/L. In addition, the present inventors also found that by adjusting the amount of sulfide to act, the concentration of sulfide ions, the pH of the second leachate, etc., it is possible to better separate the remaining zinc component from the second leachate. rice field.
Then, the third solution from which zinc has been separated until it becomes less than the analytical limit is further subjected to an oxidation treatment step, and if iron ions are further separated as iron-containing precipitates (iron separation step), the iron component is left after separation. It was found that a high-purity manganese solution can be obtained easily and inexpensively as a solution (fourth solution) (iron removal step in procedure A).

Further, as procedure B, which is another specific embodiment, the present inventors oxidized the second leachate with, for example, air to convert iron ions contained in the second leachate into, for example, hydroxides. It was found that the concentration of iron ions in the solution (third solution) left after separation of the iron component (third solution) can be significantly reduced while selectively precipitating and preferentially separating only the iron component from the second leachate ( Iron removal step in procedure B). In addition, the present inventors also found that by adjusting the pH and the like of the second leachate, it is possible to separate only the iron component from the second leachate better.
Then, the third solution from which the iron component has been separated is subjected to a sulfide precipitation treatment in which a sulfide such as sodium hydrosulfide NaHS is acted on, and the remaining zinc ions are further separated as a zinc-containing precipitate. , it was found that a high-purity manganese solution can be obtained easily and inexpensively as the fourth solution left after separation (zinc removal step in procedure B).

First, the results of experiments (A) and (B) conducted by the present inventors according to the above procedures A and B, respectively, will be described.

Experiment (A)
Manganese dry batteries and alkaline manganese dry batteries were sorted out from the waste dry batteries (sorting step), and further subjected to crushing and sieving steps to obtain granules.
The obtained granules were mixed with an acid solution under the following conditions to carry out an acid treatment step.
Acid solution: 100 mL of sulfuric acid
Sulfuric acid concentration: 1.0 mol/L (mass% concentration about 8.7%)
Acid leaching treatment time: 1 hour (stirring treatment)
Solid-liquid ratio of powder and acid solution: 100g/L
Next, the resulting mixture was filtered through a filter paper with a pore size of 1 μm to separate the first leaching liquid and the first leaching residue from solid-liquid (first solid-liquid separation step). The concentrations of manganese, zinc and iron in the separated first leaching residue were quantified by ICP emission spectroscopy. Table 1 shows the results of component analysis before and after the acid treatment step. The zinc concentration in the first leach residue separated after the acid treatment step was significantly reduced to 1.45 mass %.

From Table 1, it can be seen that although most of the zinc contained in the powder is removed by the acid treatment step, some zinc still remains. Therefore, the first leach residue separated after the acid treatment step is subjected to an acid/reducing agent treatment in which an acid solution and a reducing agent act to further leach the remaining zinc component, and the second leachate obtained is sulfide precipitation treatment, it is possible to selectively and sufficiently precipitate the remaining zinc component as will be detailed later. As a result, the inventors have come to realize that the zinc component can be removed reliably, easily, and inexpensively.

In other words, the first leaching residue separated after the acid treatment step was subjected to an acid/reducing agent treatment step in which an acid solution and a reducing agent are allowed to act. After that, the obtained mixture was subjected to a second solid-liquid separation step of filtering through a filter paper having a pore size of 1 μm to obtain a second leachate and a second leach residue. The acid concentration of the acid solution used in the acid/reducing agent treatment process is sulfuric acid concentration: 1.0 mol / L (mass% concentration about 8.7%), the reducing agent is 30% hydrogen peroxide water, and the acid leaching treatment time is Stirring treatment was performed for 1 hour. A second leachate containing at least manganese ions, zinc ions and iron ions was obtained by the acid/reducing agent treatment step and the second solid-liquid separation step.
Quantitative analysis of the manganese, zinc, and iron concentrations in the obtained second leachate by ICP emission spectrometry revealed a manganese concentration of 22,435 mg/L, a zinc concentration of 535 mg/L, and an iron concentration of 112 mg/L. rice field.

Then, the obtained second leachate was subjected to a sulfide precipitation treatment step in which sodium hydrosulfide NaHS was added as a sulfide under various conditions. Sodium hydrosulfide (NaHS) was dissolved in distilled water and added in the form of a solution.
The conditions for the sulfide precipitation treatment were as follows.
2nd leachate: 100mL
Sulfide type: sodium hydrosulfide (NaHS)
Addition amount of sulfide: 1 to 3 equivalents as sulfur to dissolved zinc pH of second leachate during reaction: 0.5 to 5
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide Treatment time: 0.5 hours after adding sodium hydrosulfide (stirring treatment)
After the sulfide precipitation treatment, suction filtration is performed with a filter paper with a pore size of 1 μm to perform solid-liquid separation (zinc separation process), and the components (zinc, iron, manganese) of the separated third solution are quantified by ICP emission spectrometry. analyzed. In the zinc separation step, clogging of the filter paper was not observed at all, and solid-liquid separation could be easily performed. The analytical values obtained were corrected for the effects of dilution due to the addition of sodium hydrosulfide solution and pH adjuster. The results obtained are shown in FIG. Manganese analysis results are not shown in FIG.

From FIG. 5(a), when the amount of sulfide added is 1 equivalent (NaHS: 1 equivalent), zinc precipitation is removed, but the analysis limit (0.1 mg / L) is exceeded and is incomplete. Moreover, it can be seen that the final removal rate of Zn is not stable when the pH of the second leachate is increased.
On the other hand, as shown in FIG. 5(b), when the added amount of sulfide is 2 equivalents (NaHS: 2 equivalents), precipitation and removal of zinc become remarkable. In particular, under the condition that the pH of the second leachate is 3 or higher, the zinc concentration in the third solution after the zinc removal step (sulfide precipitation treatment step and zinc separation step) is below the analytical limit (0.1 mg/L). It can be seen that up to . In addition, even when the amount of sulfide added shown in FIG. At that time, the zinc concentration was below the analytical limit (0.1 mg/L), and zinc precipitate removal was remarkable.

In addition, from FIG. 5, it turns out that iron precipitation removal is also performed by the zinc removal process. As shown in FIG. 5(b), when the amount of sulfide added is 2 equivalents (NaHS: 2 equivalents), iron is precipitated and removed under the condition that the pH of the second leachate is 3 or more, and the pH is 5. It can be seen that the Fe concentration is reduced to about 1 mg/L in the case of about 1 mg/L. Under the conditions shown in FIG. 5(b), although not shown, the manganese concentration also began to decrease to about 19000 mg/L. In other words, under the condition that the added amount of sulfide is 2 equivalents and the pH of the second leachate is 3 or more, it can be seen that manganese is partially precipitated and removed from the second leachate together with zinc and iron.

Moreover, even when the amount of sulfide added shown in FIG. 5(c) is 3 equivalents (NaHS: 3 equivalents), iron is precipitated and removed with the same tendency as in the case of 2 equivalents. As shown in FIG. 5(c), when the pH of the second leachate is 5, the removal of the precipitated iron is particularly remarkable, and it can be seen that iron is removed to about 0.5 mg/L. Although not shown, when the pH was 5 in FIG. 5(c), the manganese concentration decreased remarkably, and 30% or more of manganese was precipitated and removed. That is, at a sulfide loading of 3 equivalents and a second leachate pH greater than 3, in addition to removing zinc, iron and manganese also precipitate in greater amounts than at a sulfide loading of 2 equivalents. It can be seen that

As described above for experiment (A), manganese ions, zinc ions, and manganese ions, zinc ions, and According to the step of removing zinc from the second leachate containing iron ions, troubles such as clogging of filter paper during zinc separation can be avoided, and the zinc component can be smoothly precipitated, separated and removed to below the analytical limit. In addition, iron (Fe) may partially precipitate along with zinc (Zn). If the iron (Fe) concentration has been precipitated and removed to some extent, the treatment may be terminated at this stage. However, in order to remove iron to a higher degree, the present inventors proposed an iron removal step ( It was realized that an additional oxidation treatment step and an iron separation step) had to be applied.

Experiment (B)
According to the same method as in Experiment (A), the first leaching residue obtained through the sorting process, the crushing/sieving process, the acid treatment process, and the first solid-liquid separation process is treated with an acid solution and a reducing agent. After treatment with a reducing agent, a second leachate and a second leach residue were obtained. Manganese concentration, zinc concentration and iron concentration in the separated second leachate were measured by ICP emission spectrometry, and the manganese concentration was 22435 mg/L, the zinc concentration was 535 mg/L, and the iron concentration was 112 mg/L.

Next, the obtained second leachate was subjected to air aeration as oxidation treatment (oxidation treatment step). The air aeration conditions were as follows.
Blowing amount: (same volume as second leachate)/min Aeration time: 30 minutes pH of second leachate during reaction: 4-6
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide Blowing rate and aeration time are set according to normal practical conditions : 15 to 60 minutes).
Then, the entire amount of the second leachate after air aeration is sucked and filtered through a filter paper with a pore size of 1 μm to separate solid and liquid (iron separation step), and the component concentration (zinc, iron, manganese) of the separated third solution is measured by ICP emission. Measured by an analytical method. The obtained measured values were corrected for the influence of dilution with a pH adjuster. The results obtained are shown in FIG. Since precipitation of manganese and zinc due to the oxidation treatment process was hardly confirmed, FIG. 6 shows only the iron concentration in the third solution after the iron removal process (oxidation treatment process and iron separation process).

It can be seen from FIG. 6 that Fe (iron) is selectively removed by precipitation when the pH of the second leachate is 4-6. Although not shown, manganese and zinc hardly precipitated in this pH range, and although zinc was slightly precipitated and removed at pH: 6, the amount was as small as about 10 to 20 mg/L. When the pH of the second leaching solution was 5 or 6, iron precipitation removal progressed remarkably, and the iron concentration decreased to below 0.1 mg/L. In this way, the inventors have found that the iron concentration can be significantly reduced simply by subjecting the second leachate to air aeration, which is an inexpensive oxidation treatment.

In FIG. 6, the second leachate adjusted to pH: 5 was subjected to air aeration (oxidation treatment) to reduce the iron concentration to less than 0.1 mg / L, and the second leachate obtained by performing the iron separation process by solid-liquid separation The three solutions were further subjected to a sulfide precipitation treatment process under various conditions.
The conditions for the sulfide precipitation treatment were as follows.
Third solution: 100 mL
Sulfide type: sodium hydrosulfide (NaHS)
Addition amount of sulfide: 1 to 3 equivalents as sulfur to dissolved zinc pH of third solution during reaction: 0.5 to 5
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide Treatment time: 0.5 hours after adding sodium hydrosulfide (stirring treatment)
After the above-described sulfide precipitation treatment step, suction filtration was performed with a filter paper having a pore size of 1 μm to perform solid-liquid separation (zinc separation step), and the components of the separated fourth solution were analyzed by ICP emission spectrometry. In the zinc separation step, clogging of the filter paper was not observed at all, and solid-liquid separation could be easily performed.

As a result, when the amount of sulfide added is 1 equivalent (NaHS: 1 equivalent), zinc precipitation is removed, but it is incomplete because it exceeds the analytical limit (0.1 mg / L). It was found that the final Zn removal rate was not stable when the pH of the solution was increased.
On the other hand, when the amount of sulfide added is 2 equivalents (NaHS: 2 equivalents), zinc precipitate removal becomes remarkable. It was found that the concentration of zinc in the solution was precipitated and removed until it fell below the analytical limit (0.1 mg/L).
Further, it was found that even when the amount of sulfide added is 3 equivalents (NaHS: 3 equivalents), the same tendency as in the case of 2 equivalents is exhibited, and precipitation of zinc is remarkably removed. When the amount of sulfide added was 3 equivalents (NaHS: 3 equivalents), when the pH of the third solution was about 5, the removal of precipitated manganese tended to increase.

As described above for experiment (B), manganese ions, zinc ions, and manganese ions, zinc ions, and If the second leachate containing iron ions is first subjected to oxidation treatment, it is possible to obtain a solution in which most of the iron components are precipitated, separated and removed (iron removal process). Then, if the separated third solution is subjected to a sulfide precipitation treatment step in which sulfide acts on it, troubles such as filter paper clogging during zinc separation can be avoided, and the zinc component can be reduced to below the analysis limit without delay. can be precipitated and removed (zinc removal step).

Thus, according to Experiments (A) and (B), if the first leaching residue obtained by removing most of the zinc in the granules in advance by the acid treatment step as the pretreatment step is used, the zinc removal step and It has been found that both zinc and iron can be reliably and simply precipitated, separated and removed, and a highly pure manganese-containing solution can be efficiently produced regardless of the order of the iron removal step.

The present invention has been completed by further studies based on such findings. That is, the gist of the present invention is as follows.
(1) a sorting step of sorting out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing and sieving step of crushing and sieving one or both of the manganese dry battery and the alkaline manganese dry battery selected in the sorting step to obtain powders;
an acid treatment step of mixing an acid solution with the granular material obtained in the crushing and sieving step to obtain a first leachate and a first leach residue;
a first solid-liquid separation step of separating the first leachate obtained in the acid treatment step and the first leach residue;
an acid/reducing agent treatment step of mixing the first leaching residue separated in the first solid-liquid separation step with an acid solution and a reducing agent to obtain a second leaching solution and a second leaching residue;
a second solid-liquid separation step of separating the second leachate obtained in the acid/reducing agent treatment step and the second leach residue;
Of the zinc ions, iron ions, and manganese ions contained in the second leachate, the zinc ions and iron ions are removed from the second leachate separated in the second solid-liquid separation step, and the manganese a manganese extraction step of obtaining a solution containing ions;
A method for recovering manganese from waste batteries by applying in this order,
The manganese extraction step is
a zinc removal step including a sulfide precipitation treatment step of reacting the zinc ions with sulfide to precipitate the zinc ions, and a zinc separation step of separating the obtained zinc-containing precipitate;
an iron removal step comprising an oxidation treatment step of oxidizing the iron ions to precipitate the iron ions, and an iron separation step of separating the resulting iron-containing precipitate;
A method for recovering manganese from waste dry batteries, comprising obtaining a manganese-containing solution by including in random order.

(2) In the above (1), wherein the acid solution in the acid treatment step is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. A method for recovering manganese from waste dry batteries described.

(3) Manganese from waste dry batteries according to (1) or (2), wherein the solid-liquid ratio between the powder and the acid solution in the acid treatment step is 50 g/L or more. collection method.

(4) The acid solution in the acid/reducing agent treatment step is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. A method for recovering manganese from waste dry batteries according to any one of 1) to (3).

(5) The reducing agent in the acid/reducing agent treatment step is any one of hydrogen peroxide, sodium sulfide, sodium hydrogen sulfite, sodium thiosulfate, and iron sulfate. (4) A method for recovering manganese from waste dry batteries according to any one of (4).

(6) the manganese extraction step is performed in the order of the zinc removal step and then the iron removal step;
In the zinc removal step, the second leachate is subjected to a sulfide precipitation treatment step of causing sulfide to act on the second leachate to precipitate zinc ions in the second leachate. Performing a zinc separation step for solid-liquid separation from the third solution containing ions,
In the iron-removing step, after performing an oxidation treatment step of oxidizing the third solution obtained in the zinc-removing step to precipitate iron ions in the third solution, the resulting iron-containing precipitate and manganese The method for recovering manganese from waste dry batteries according to any one of the above (1) to (5), characterized by performing an iron separation step of solid-liquid separation from the fourth solution containing ions.

(7) The method for recovering manganese from waste dry batteries according to (6) above, wherein in the sulfide precipitation treatment step, the pH of the second leachate is adjusted to pH 2 or more and 6 or less.

(8) In the oxidation treatment step, the third solution containing manganese ions and iron ions is aerated with air, or an oxidizing agent is added to the third solution, and the third solution is The method for recovering manganese from waste dry batteries according to (6) or (7) above, wherein the pH is adjusted to 3 or more and 7 or less.

(9) the manganese extraction step is performed in the order of the iron removal step and then the zinc removal step;
In the iron removal step, the second leachate is subjected to an oxidation treatment step of oxidizing the second leachate to precipitate iron ions in the second leachate. 3 subjected to an iron separation process for solid-liquid separation from the solution,
In the zinc removal step, the third solution obtained in the iron removal step is subjected to a sulfide precipitation treatment step of causing sulfide to act on the third solution to precipitate zinc ions in the third solution. The method for recovering manganese from waste dry batteries according to any one of the above (1) to (5), characterized in that a zinc separation step is performed for solid-liquid separation of the contained precipitate and the fourth solution containing manganese ions. .

(10) In the sulfide precipitation treatment step, the pH of the third solution containing manganese ions and zinc ions is adjusted to 2 or more and 6 or less, from the waste dry battery according to (9). Manganese recovery method.

(11) The above (9) or (10), wherein in the oxidation treatment step, the second leachate is aerated with air, and the pH of the second leachate is adjusted to 3 or more and 7 or less. The method for recovering manganese from waste dry batteries according to 1.

(12) Any one of (1) to (11) above, wherein the sulfide used in the sulfide precipitation treatment step is any one of sodium hydrosulfide, sodium sulfide, and hydrogen sulfide. A method for recovering manganese from waste dry batteries described.

(13) a sorting device for sorting out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing device for obtaining a crushed product by inserting one or both of the manganese dry batteries and alkaline manganese dry batteries sorted by the sorting device and subjecting them to crushing treatment;
a sieving device for obtaining powder by sieving the crushed material obtained by the crushing device;
an acid treatment tank for acid-treating the granular material obtained by the sieving device;
a first solid-liquid separator for separating the first leachate obtained in the acid treatment tank from the first leach residue;
an acid/reducing agent treatment tank in which an acid solution and a reducing agent are applied to the first leaching residue separated by the first solid-liquid separation device;
a second solid-liquid separator for separating the second leachate obtained in the acid/reducing agent treatment tank from the second leach residue;
Of the zinc ions, iron ions, and manganese ions contained in the second leachate, the zinc ions and iron ions are removed from the second leachate separated by the second solid-liquid separator, and the manganese a group of manganese extractors for obtaining a solution containing ions;
Manganese recovery equipment from waste dry batteries, comprising in this order,
The manganese extraction device group
a group of zinc removal devices including a sulfide precipitation treatment tank for causing sulfide to act on the zinc ions to precipitate the zinc ions;
an iron removal device group including an oxidation treatment tank for oxidizing the iron ions to precipitate the iron ions, and an iron separation device for solid-liquid separation of the obtained iron-containing precipitate;
Manganese recovery equipment from waste dry batteries, characterized in that a manganese-containing solution is obtained by including in random order.

According to the present invention, the manganese component, which is a valuable component contained in waste dry batteries, can be separated from the carbon component, zinc component, and iron component with high accuracy and ease, and the manganese component can be used as a raw material for secondary battery electrode materials. High-purity manganese can be recovered at a high yield and at a low cost, and has a remarkable industrial effect.

BRIEF DESCRIPTION OF THE DRAWINGS It is a flow explaining the process of the manganese recovery method of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a flow explaining one Embodiment (procedure A) of the manganese recovery method of this invention. It is a flow explaining other embodiment (procedure B) of the manganese recovery method of this invention. It is the X-ray diffraction data of the granular material before and after the acid treatment process. Sulfide addition amount ((a) NaHS: 1 equivalent, (b) NaHS: 2 equivalents, (c) NaHS: 3 equivalents on zinc and iron precipitation removal in the sulfide precipitation treatment process according to the flow of FIG. 2 ) and pH conditions. FIG. 4 is a graph showing the effect of pH on the removal of iron precipitates in the oxidation treatment process according to the flow of FIG. 3. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining one Embodiment (structure A) of the manganese recovery equipment of this invention. FIG. 3 is a schematic diagram illustrating another embodiment (configuration B) of the manganese recovery facility of the present invention;

The present invention is directed to waste dry batteries, and the manganese component, which is a valuable component contained in waste dry batteries, is separated from the carbon component, zinc component, and iron component contained together in the waste dry battery, and is easily prepared as a highly pure manganese-containing solution. It is a method and equipment for recovering manganese from waste dry batteries. Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The following embodiments show preferred examples of the present invention, and the present invention is not limited by these examples.

(Manganese recovery method)
Manganese recovery method of the present invention, as shown in FIG. and a manganese extraction step. Also, the manganese extraction process includes a predetermined zinc removal process and an iron removal process in random order.
When the manganese recovery method of the present invention follows the predetermined steps described above, components other than manganese contained in waste dry batteries can be sequentially and reliably and easily removed. As a result, according to the method for recovering manganese of the present invention, the manganese component can be easily recovered from waste dry batteries in such a high purity that it can be used as a raw material for secondary battery electrode materials. The manganese recovery method of the present invention can be suitably carried out using a manganese recovery facility to be described later.

Sorting process Waste dry batteries are generally collected in a form in which various kinds of dry batteries are mixed. Therefore, in the present invention, one or both of manganese dry batteries and alkaline manganese dry batteries (manganese dry batteries and/or alkaline manganese dry batteries) are sorted out of collected waste dry batteries. In order to efficiently extract the manganese component in a later step, only manganese dry batteries may be sorted, only alkaline manganese dry batteries may be sorted, or both manganese dry batteries and alkaline manganese dry batteries may be sorted. . As a sorting method, any method such as manual sorting or mechanical sorting using a sorting device may be used.

Crushing/Sieving Process Next, the manganese dry batteries and/or alkaline manganese dry batteries screened in the screening process are crushed. The purpose of crushing is to remove as much as possible materials containing components other than manganese, zinc and carbon from the constituent materials of the manganese dry battery and/or alkaline manganese dry battery selected in the screening process.
When these waste dry batteries are crushed, packaging materials (iron, plastic, paper, etc.), zinc cans, which are the anode material for manganese dry batteries, and brass rods, which are current collectors for alkaline manganese dry batteries, are turned into foil-like or flake-like solids. become things. On the other hand, manganese dioxide, which is a positive electrode material, carbon rods, which are current collectors for manganese dry batteries, zinc powder, which is a negative electrode material for alkaline manganese dry batteries, and MnO(OH), Zn(OH) ₂ and Mn(OH) generated by discharge _2. Compounds such as ZnO, and various electrolytic solutions become finer particles than foil-like or flake-like solids.

A crushing device is usually used to crush waste dry batteries. The type of the crushing device is not particularly limited, and for example, it is preferable to use a type that can separate solids such as packaging materials constituting the dry battery from granules after crushing. As such a crushing device, for example, a twin-shaft rotary crushing device is exemplified.
The mesh size of the sieve used for sieving the crushed material (sieving between foil-like or flake-like solids and powder) is preferably 1 mm or more, preferably 20 mm or less, and 10 mm or less. More preferably, 3 mm or less is even more preferable. The mesh size of the sieve is preferably about 1 to 20 mm, more preferably about 1 to 10 mm, even more preferably about 1 to 3 mm. If the mesh opening of the sieve is at least the above lower limit, a larger amount of powder containing a manganese component can be secured. In addition, if the sieve opening is equal to or less than the above upper limit, solid matter containing unintended components other than manganese can be further removed, and subsequent steps can be performed more efficiently.

Therefore, if waste dry batteries are crushed and then sieved using the above-mentioned sieve with mesh openings, large solids such as packaging materials are removed from the waste dry batteries, and powder grains mainly containing carbon along with manganese and zinc components are removed. body can be obtained efficiently.
Thus, the granules obtained through the crushing and sieving process are the main constituent materials of manganese dry batteries and / or alkaline manganese dry batteries, manganese dioxide, carbon, zinc chloride or ammonium chloride, caustic potash, and further, It is a mixture of powders such as MnO(OH), Zn(OH) ₂ , Mn(OH) ₂ and ZnO generated by discharge. In addition, usually, an iron component is inevitably mixed in the powder.

Acid treatment step In the acid treatment step, the granules obtained through the crushing and sieving step are mixed with an acid solution (acid solution for the acid treatment step), and zinc in the granules is mainly added to the first leachate. Leaching and obtaining a first leach residue with reduced zinc content.

The acid used in the acid solution in the acid treatment step may be a common acid, and sulfuric acid, nitric acid, hydrochloric acid or other acids may be used. Although it can be appropriately selected depending on the price and purpose, it is preferable to use sulfuric acid or hydrochloric acid as the acid solution in consideration of cost, ease of procurement, and the like.
When sulfuric acid is used, it is preferable to use dilute sulfuric acid with a sulfuric acid concentration of 1.4% or more and 45% or less by mass. More specifically, the sulfuric acid concentration is preferably 1.4% or higher, more preferably 2% or higher, even more preferably 5% or higher, preferably 45% or lower, more preferably 30% or lower, and even more preferably 25% or lower. The sulfuric acid is more preferably dilute sulfuric acid with a concentration of 2% or more and 30% or less, and more preferably dilute sulfuric acid with a concentration of 5% or more and 25% or less.
When hydrochloric acid is used, it is preferable to use dilute hydrochloric acid with a hydrochloric acid concentration of 1% or more and 14% or less by mass. More specifically, the hydrochloric acid concentration is preferably 1% or higher, more preferably 2% or higher, preferably 14% or lower, and more preferably 8% or lower. Hydrochloric acid is more preferably dilute hydrochloric acid with a concentration of 2% or more and 8% or less.
If the concentration of the acid solution in the acid treatment step is less than the above lower limit, the zinc component in the granules will not be sufficiently leached into the first leaching solution, and a large amount of fine zinc-containing precipitates will be formed in the subsequent zinc removal step. easy to generate. As a result, zinc-containing precipitates clog filter paper, filter cloth, etc. in the zinc separation step, making it difficult to simply remove the zinc component. On the other hand, if the concentration of the acid solution in the acid treatment step exceeds the above upper limit, even manganese, which is the purpose of recovery, is likely to be excessively leached into the first leachate, making it difficult to finally obtain a manganese-containing solution of high concentration.

Any commercially available sulfuric acid or hydrochloric acid can be used, but the cost of the acid solution can be reduced by using diluted waste acid for industrial use or containing less harmful metal components. Also, the "mass % concentration" herein is a value obtained by dividing the mass of the acid in the acid solution by the mass of the entire solution and multiplying by 100.

In addition, when using any acid solution, the acid concentration required for leaching the zinc component depends on the solid-liquid ratio between the powder and the acid solution, the amount of the powder, the content of zinc in the powder, It varies depending on the form of zinc in the granules. Therefore, it is preferable to determine the optimum acid concentration by performing a preliminary experiment assuming an actual machine in advance.

The solid-liquid ratio (particle (g)/acid solution (L)) between the powder and the acid solution in the acid treatment step is preferably 50 g/L or more, more preferably 100 g/L or more, and 500 g/L or less. preferable. If the solid-liquid ratio is less than the above lower limit, the size of the reaction vessel required for treating the powder becomes large, resulting in increased facility costs. In addition, the amount of the acid solution becomes excessive with respect to the granules, and even manganese, which is the target component, tends to leach out into the first leachate. On the other hand, if the solid-liquid ratio exceeds the above upper limit, the viscosity of the mixture of the powder and the acid solution increases, making it difficult to sufficiently stir the mixture. In addition, the amount of the acid solution is too small for the granules, making it difficult for the acid solution to sufficiently leach zinc into the first leaching solution, making it difficult to efficiently remove the zinc component from the granules.

The temperature at which the powder is immersed in the acid solution in the acid treatment step can be arbitrarily set within a range in which the water in the acid solution does not solidify or boil. can be done.
The stirring time of the granules in the acid solution in the acid treatment step is preferably 15 minutes or more, and preferably 2 hours or less. If the stirring time is less than 15 minutes, the zinc component may not be sufficiently leached. Further, even if the stirring time is extended beyond 2 hours, the zinc leaching rate does not change, and the productivity may be inferior.
The stirring speed of the granules in the acid solution in the acid treatment step is not particularly limited, and can be arbitrarily set within a range in which the liquid flows.

First Solid-Liquid Separation Step In the first solid-liquid separation step, the first leachate obtained in the acid treatment step and the first leach residue are subjected to solid-liquid separation. The separated first leachate usually contains leached zinc ions and may further contain manganese ions and iron ions partially dissolved in the acid treatment step along with the zinc. On the other hand, the separated solid first leach residue mainly contains manganese and iron, and residual zinc.
The solid-liquid separation means is not particularly limited. For the solid-liquid separation step, it is preferable to use a commonly used means such as gravity sedimentation, filtration, centrifugation, filter press, membrane separation, and the like.

Acid/reducing agent treatment step In the acid/reducing agent treatment step, an acid solution (an acid solution for the acid/reducing agent treatment step) and A reducing agent is mixed, and the manganese component contained in the first leaching residue is almost completely leached into the second leaching solution obtained in the next step.
Here, the term "almost completely" as used herein means that the target component is (in this case manganese) is below the analytical limit, for example below 0.1 mg/L.

The acid solution in the acid/reducing agent treatment step is mainly added for leaching manganese components while further leaching zinc components still remaining in the first leaching residue. The acid used in the acid solution may be a common acid, and can suitably follow the acid type and conditions in the acid treatment step described above.
If the concentration of the acid solution in the acid/reducing agent treatment step is less than the lower limit described above, the manganese component in the first leach residue is difficult to sufficiently leach into the second leach solution, and the manganese recovery rate tends to decrease. On the other hand, if the concentration of the acid solution in the acid/reducing agent treatment step exceeds the above-described upper limit, the amount of alkali chemicals required for pH adjustment in the subsequent steps increases, and there is a concern that costs will increase.
Note that the zinc component remaining in the first leaching residue after the acid treatment process is almost completely dissolved (leached out) by increasing the acid concentration regardless of the presence or absence of the reducing agent.

In addition, from the viewpoint of improving the efficiency of the acid/reducing agent treatment, the solid-liquid ratio of the first leaching residue and the acid solution in the acid/reducing agent treatment process (first leaching residue (g)/acid solution (L)) is preferably 50 g/L or more. On the other hand, when the solid-liquid ratio exceeds 800 g/L, there is a possibility that the viscosity will rise and handling problems will occur, or the yield will deteriorate during the solid-liquid separation step. Therefore, the solid-liquid ratio is preferably 800 g/L or less. As for the treatment temperature (ambient temperature, acid solution temperature, etc.) of the acid/reducing agent treatment, a sufficient effect can be obtained even at room temperature (around 15 to 25° C.), but heating may be performed. The heating temperature can be, for example, 60-80°C. If heating is performed, the reaction efficiency can be expected to improve as the temperature is raised within a range in which the treatment solution does not boil. The processing time of the acid/reducing agent treatment is preferably 5 minutes or longer, and preferably 6 hours or shorter.

The reducing agent is mainly added to reduce the manganese component having a valence that is difficult to dissolve in acid such as trivalent or tetravalent contained in the first leaching residue, and is added for good leaching. can be applied. Hydrogen peroxide _{H2O2 ,} sodium sulfide _Na2S.9H2O , sodium hydrogen sulfite _{NaHSO3 ,} sodium _{thiosulfate Na2S2O3} , iron _{sulfate FeSO4.7H2O are} preferred as reducing agents. I can give an example. A sulfur-based reducing agent may generate corrosive gases such as sulfurous acid gas and hydrogen sulfide gas, and caution is required from the viewpoint of safety. From this point of view, the reducing agent is more preferably hydrogen peroxide H ₂ O ₂ .
The amount (g) of the reducing agent added depends on the form of manganese contained in the first leaching residue, so it is not particularly limited, but it is sufficient if it is about 1 to 500 g/L with respect to the acid solution (L). be.

Second Solid-Liquid Separation Step In the second solid-liquid separation step, the second leachate obtained in the acid/reducing agent treatment step and the second leach residue are subjected to solid-liquid separation. The separated second leachate contains manganese ions, iron ions, and residual zinc ions. On the other hand, the separated solid secondary leach residue is primarily the result of residual carbon. As a result, carbon can be separated from the manganese component, zinc component, and iron component contained in the granules, followed by the first leaching residue.
The solid-liquid separation means is not particularly limited. For the solid-liquid separation step, it is preferable to use a commonly used means such as gravity sedimentation, filtration, centrifugation, filter press, membrane separation, and the like.

Manganese Extraction Step A manganese extraction step of removing zinc ions and iron ions from the second leachate separated in the second solid-liquid separation step to obtain a highly pure solution containing manganese ions (manganese-containing solution). There is a need to do. Specifically, the manganese extraction step includes a given zinc removal step and an iron removal step in random order. More specifically, the zinc removal step included in the manganese extraction step includes a sulfide precipitation treatment step in which zinc ions are reacted with sulfide to precipitate zinc ions, and a zinc separation step in which the resulting zinc-containing precipitate is separated. including. Further, the iron removal step included in the manganese extraction step includes an oxidation treatment step of oxidizing iron ions to precipitate iron ions, and an iron separation step of separating the obtained iron-containing precipitate.
In this way, in the manganese extraction step, zinc ions and iron ions are selectively precipitated, respectively, and the zinc ions and iron ions are reliably removed from the second leachate. It is highly pure and can be easily recovered.

The manganese extraction step may be preceded by a zinc removal step comprising a sulfide precipitation treatment step that preferentially precipitates zinc ions and a zinc separation step (procedure A), or an oxidation step that preferentially precipitates iron ions. An iron removal step including a treatment step and an iron separation step may be performed first (Procedure B). From the viewpoint of facilitating simplification of the process, it is preferable to perform the iron removal process first (procedure B).
Procedure A first obtains a mixture of a zinc-containing precipitate and a third solution containing manganese and iron ions from the second leachate and then separates them. Also, in procedure B, first, a mixture of the iron-containing precipitate and the third solution containing manganese ions and zinc ions is obtained from the second leachate, and then these are separated. Procedures A and B will be described in detail below.

Zinc removal step (procedure A)
In the zinc removal step in procedure (A), the second leachate that has undergone solid-liquid separation is first subjected to a sulfide precipitation treatment step. In this sulfide precipitation treatment step, sulfide is caused to act on the second leachate to precipitate zinc ions that mainly remain among the ions contained in the second leachate as zinc sulfide, making it removable from the second leachate. . This treatment yields a mixture of a third solution containing manganese ions and iron ions and a zinc-containing precipitate from the second leachate.

The second leachate separated in the second solid-liquid separation step contains manganese ions, iron ions, and residual zinc ions. The ions react with the sulfide ion S ^2- to form and precipitate sulfide. The susceptibility to precipitation of this sulfide depends on the solubility product _KSP . The solubility products of manganese, zinc and iron sulfides are shown below.
MnS: _Ksp = 2.5 x 10 ^-10
ZnS: _Ksp = 1.6 × 10 ^-24
FeS: _KSP = 6.3 × 10 ^-18
(Lange, NA: Lange's Handbook of Chemistry. Thirteenth edition 1985)
The smaller the value of the solubility product _KSP , the easier it is to form sulfides. Therefore, among manganese, zinc, and iron, zinc (Zn) is the easiest to form sulfides. Therefore, when sulfide is caused to act on the second leachate containing ions of manganese, zinc and iron, zinc (Zn) can be selectively precipitated as sulfide. By adjusting the concentration of sulfide ions and the pH of the second leachate, the zinc ion concentration in the second leachate can be easily reduced below the analytical limit (0.1 mg/L).
Here, as described above, if the second leachate contains a large amount of zinc ions, a large amount of fine zinc-containing precipitates will be generated by the sulfide precipitation treatment step, so the filter cloth, etc., will be removed during the subsequent solid-liquid separation. Clogging is likely to occur, making the zinc separation process difficult. However, in the present invention, since most of the zinc component in the powder is removed in advance in the acid treatment step prior to the sulfide precipitation treatment step, the quantity and quality of the zinc-containing precipitate generated in the sulfide precipitation treatment step are reduced. can be controlled, and the zinc separation step, which will be described later, can be performed simply and efficiently.

Suitable sulfides to be acted on include sodium hydrosulfide NaHS, sodium sulfide NaS, and hydrogen sulfide _H2S . Since hydrogen sulfide is a gas, it must be aerated. Therefore, sodium hydrosulfide and sodium sulfide are more preferable as the sulfide to act.

The amount of sulfide to act is preferably 1.1 equivalents or more and 5 equivalents or less as sulfur S to dissolved zinc. The amount of sulfide is preferably 1.1 equivalents or more, more preferably 2 equivalents or more, preferably 5 equivalents or less, more preferably 3 equivalents or less, and still more preferably less than 3 equivalents as sulfur S relative to dissolved zinc. If the amount of sulfide is at least the above lower limit, zinc ions can be more favorably precipitated. Further, if the amount of sulfide is equal to or less than the above lower limit, it is easier to suppress unintended precipitation of manganese ions, and it is possible to prevent an excessive amount of sulfide to act from becoming economically disadvantageous.

In addition, if the pH of the second leaching solution when the sulfide is applied is too low, less than 2, the precipitation of zinc tends to be insufficient. The reduction in the amount is remarkable, manganese loss progresses, and the manganese yield tends to decrease. From this point of view, the pH of the second leachate in the sulfide precipitation treatment step 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 2 or more and 6 or less, more preferably 2 or more and 5 or less, even more preferably 3 or more and 5 or less, and still more preferably 3 or more and less than 5.

Subsequently, in the zinc removal step in procedure (A), the mixture obtained in the above-described sulfide precipitation treatment step is separated into the third solution and the zinc-containing precipitate to remove the zinc component.
More specifically, the third solution containing manganese ions and iron ions obtained in the sulfide precipitation treatment step is separated from the zinc-containing precipitate, which is mainly the remaining zinc sulfide. As a result, the zinc component can be easily separated from the mixture after the sulfide precipitation treatment step, and a third solution containing manganese ions and iron ions can be obtained. Separation means is not particularly limited, and may follow the solid-liquid separation process described above. If the zinc-containing precipitate formed is large or fine, troubles such as clogging of the filter cloth are likely to occur during zinc separation. Since it is removed, the amount and refinement of the zinc-containing precipitate can be suppressed, and the zinc separation step can be performed simply and efficiently.
In addition, in the sulfide precipitation treatment described above, part of the iron (Fe) content may be precipitated and removed from the solution. In this case, if the iron content is removed below the preset iron component concentration, the treatment may be finished at this stage. However, in procedure (A), an iron removal step, which will be described later, is further performed in order to further separate and remove the iron component to obtain a high-purity manganese component.

Iron removal step (procedure A)
In procedure (A), following the zinc removal step described above, an iron removal step is performed. In the iron removal step in the procedure (A), first, the third solution containing manganese ions and iron ions obtained in the previous zinc removal step is subjected to an oxidation treatment step, and the iron ions in the third solution are converted to iron-containing As a precipitate, the iron component can be separated and removed. By this treatment, a mixture of the fourth solution (manganese-containing solution) containing highly pure manganese ions and the iron-containing precipitate is obtained from the third solution.

As the oxidation treatment method, it is sufficient to follow the oxidation treatment method in the procedure (B) described later, including the suitable pH of the third solution. Here, if the third solution obtained through the sulfide precipitation treatment step is subjected to air aeration under practical conditions, the iron component in the third solution may not be completely separated and removed. This is because the sulfide added in the sulfide precipitation process acts as a reducing agent in this step. It is believed that this reducing agent consumes the oxygen supplied by air aeration, and depending on the amount of air aeration, the amount of oxygen becomes insufficient, and iron that cannot be separated and removed remains in the solution after treatment. If air aeration is continued, the sulfide will become sulfate ions, and finally the solution will become an oxidizing atmosphere, and the iron component will also precipitate. However, this method requires a long aeration time and is not practical.

Therefore, in the oxidation treatment step of procedure (A), it is preferable to add an oxidizing agent as a finishing oxidation treatment after air aeration. The amount of the oxidizing agent to be added is preferably adjusted so that the oxidation-reduction potential (vs. SHE) is measured and the oxidation-reduction potential is 550 mV or more. Suitable oxidizing agents include hydrogen peroxide and potassium permanganate.

After performing the zinc removal step, if the oxidation treatment step is performed after leaving it for an appropriate period of time, the iron component can be sufficiently precipitated only by air aeration without performing the final oxidation treatment. This is because hydrogen sulfide, which is a reducing substance in the third solution generated in the sulfide precipitation treatment step in the previous stage, is diffused into the air, and the third solution is easily oxidized, that is, the redox potential is easily increased. It is thought that this is due to the fact that The proper period here is different depending on the storage conditions such as whether it is a closed system or an open system.

Then, in the iron removal step in procedure (A), the mixture obtained in the oxidation treatment step described above is separated into the fourth solution and the iron-containing precipitate to remove the iron component. Thus, a highly pure manganese-containing solution (fourth solution) can be recovered.
Separation means is not particularly limited, and may follow the solid-liquid separation process described above.

Iron removal step (procedure B)
Next, in the iron removal step in procedure (B), the second leachate obtained in the solid-liquid separation step is first subjected to an oxidation treatment. In this oxidation treatment, the second leachate is oxidized to precipitate iron ions among the ions contained in the second leachate as iron-containing precipitates, so that the iron component can first be removed from the second leachate. This treatment yields a mixture of a third solution containing manganese and zinc ions and an iron-containing precipitate from the second leachate.

As the oxidation treatment method, a commonly used oxidation treatment method can be applied, but in the present embodiment, only air aeration, which is an inexpensive oxidation treatment method, is sufficient. As for the air aeration conditions, it is economical to use normal practical conditions (blowing volume: (0.1 to 1 volume of leachate volume)/minute, aeration time: 15 to 60 minutes). from the point of view. As the finishing oxidation, a process of adding an oxidizing agent may be added.

The oxidation treatment is preferably carried out by adjusting the pH of the second leachate using a pH adjuster. If the pH of the second leachate is too low, i.e. less than 3, the iron component will be difficult to precipitate. On the other hand, if the pH of the second leachate exceeds 7 and is too high, the manganese component also tends to precipitate at the same time. Therefore, it is preferable to adjust the second leaching solution to a pH range of 3-7. The second leaching solution preferably has a pH of 5 or higher, more preferably a pH of 6 or lower, and still more preferably a pH of around 5 to 6. As a result, the iron component can be precipitated, separated and removed from the second leachate, and a high-purity manganese-containing solution containing few impurities can be obtained.

Subsequently, in the iron removal step in procedure (B), the mixture obtained in the oxidation treatment step described above is combined with a third solution containing manganese ions and zinc ions and an iron-containing precipitate that may mainly contain iron hydroxide. separate into Thereby, the iron component can be easily separated and removed from the mixture after the oxidation treatment step, and the third solution containing the manganese component and the zinc component can be obtained.
Separation means is not particularly limited, and may follow the solid-liquid separation process described above.

Zinc removal step (procedure B)
In procedure (B), following the iron removal step described above, a zinc removal step is performed. In the step of removing zinc in procedure (B), the third solution obtained in the previous step of removing iron is reacted with sulfide, and among the ions in the third solution, mainly zinc ions are precipitated as zinc sulfide, and residual the zinc component to be removed from the third solution. By this treatment, a mixture of the fourth solution (manganese-containing solution) containing manganese ions with high purity and the zinc-containing precipitate is obtained from the third solution.

The third solution separated in the previous iron removal step contains manganese ions and residual zinc ions, and when sulfide is applied to the third solution, the sulfide precipitation treatment step of procedure (A) described above Zinc components are selectively precipitated as sulfides following a similar mechanism. Then, by adjusting the amount of sulfide added, the concentration of sulfide ions, and the pH of the third solution, the zinc ion concentration in the third solution can be easily reduced below the analytical limit (0.1 mg/L). can be done.
The type of sulfide and the preferred pH of the third solution may follow the preferred type of sulfide and the pH of the second leachate in the sulfide precipitation treatment of procedure (A) described above. The pH of the third solution is particularly preferably pH:4.
The amount of sulfide to be acted is preferably 1.1 equivalents or more, more preferably 2 equivalents or more, and preferably 5 equivalents or less as sulfur S to dissolved zinc. If the amount of sulfide to be acted is less than 1.1 equivalents, zinc precipitate removal is progressing but incomplete, and the final removal rate is not stable. If the amount of sulfide to be acted is 2 equivalents or more, precipitation removal of zinc becomes remarkable. Moreover, when the amount of sulfide to be acted exceeds 5 equivalents, the amount of sulfide to be acted becomes excessive, and manganese may also precipitate and be removed.

Then, in the zinc removing step in the procedure (B), the mixture obtained in the above-described sulfide precipitation treatment step is separated into the fourth solution and the zinc-containing precipitate, which is mainly zinc sulfide precipitated, and the zinc component to remove In this way, the remaining zinc component can also be removed, and a highly pure solution containing only the manganese component can be easily recovered.
Here, as described above, if the third solution contains a large amount of zinc ions, a large amount of fine zinc-containing precipitates are generated by the sulfide precipitation treatment step, so the filter cloth or the like is used during the subsequent solid-liquid separation. Clogging is likely to occur, making the zinc separation process difficult. However, in the present invention, since most of the zinc component in the powder is removed in advance in the acid treatment step prior to the sulfide precipitation treatment step, the quantity and quality of the zinc-containing precipitate generated in the sulfide precipitation treatment step are reduced. can be controlled, and the zinc separation step can be performed simply and efficiently.
Separation means is not particularly limited, and may follow the solid-liquid separation process described above.

By sequentially going through the above steps, the carbon, zinc, and iron components other than the manganese component contained in the waste dry battery can be almost completely separated and removed. It can be recovered as a pure manganese-containing solution with a high yield.
The obtained manganese-containing solution may be used for various purposes as a high-purity manganese hydroxide by, for example, alkali precipitation. Also, the obtained manganese-containing solution may be mixed with another metal such as Ni and then subjected to an alkali precipitation treatment or the like, and used as a material for a secondary battery electrode material.

(manganese recovery facility)
Next, the manganese recovery equipment of the present invention will be described. The manganese recovery equipment of the present invention includes a sorting device, a crushing device, a sieving device, an acid treatment tank, a first solid-liquid separation device, an acid/reducing agent treatment tank, a second solid-liquid separation device, and a group of manganese extraction devices. and have the same features and effects as the manganese recovery method of the present invention. Also, the group of manganese extraction devices includes a group of predetermined zinc removal devices and a group of iron removal devices in random order.
And the manganese recovery equipment of this invention can be suitably utilized, for example, when implementing the manganese recovery method of this invention.

Configuration A
As one aspect of the recovery equipment of the present invention, FIG. 7 shows a configuration (A) capable of suitably performing the above procedure (A). As schematically shown in FIG. 7, the recovery equipment includes a sorting device 10, a crushing device 20a, a sieving device 20b, an acid treatment tank 30, a first solid-liquid separation device 40, and an acid/reducing agent. A 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, They can be provided in this order from upstream to downstream. Here, the sulfide precipitation treatment tank 70 and the zinc separator 80 constitute a group of zinc removal equipment, and the oxidation treatment tank 90 and the iron separation equipment 100 constitute a group of iron removal equipment. In addition, the group of zinc removal devices and the group of iron removal devices constitute the group of manganese extraction devices.

The sorting device 10 sorts out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries. The type of sorting device is not particularly limited, and a device that sorts by using shape, radiation, or the like can be preferably exemplified. It should be noted that sorting of waste dry batteries may be carried out manually.
As the crushing device 20a, any ordinary crusher can be applied, but a twin-shaft rotary crusher is preferable.
The sieving device 20b is preferably equipped with a sieve with an opening of 1 mm or more and 20 mm or less. The mesh size of the sieving device 20b is preferably about 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 reason as described above for the manganese recovery method.

The acid treatment tank 30 and the acid/reducing agent treatment tank 50 mix the granules and the acid solution and the first leaching residue with the acid solution and the reducing agent, respectively, to advance the leaching reaction. It is preferable to use a general stirring tank equipped with a stirrer in the tank.

The sulfide sedimentation treatment tank 70 is preferably a general stirring tank equipped with a stirrer in order to subject the second leachate to a sulfide treatment in which sulfide acts on the second leachate.
Further, the oxidation treatment tank 90 is preferably a general stirring tank equipped with a stirrer in order to oxidize the third solution.

Each of the first solid-liquid separator 40, the second solid-liquid separator 60, the zinc separator 80, and the iron separator 100 can be, for example, a gravity sedimentation separator, a filtration device, a centrifugal separator, a filter press, a membrane A device selected from separation devices and the like can be used. In addition, it is preferable to equip each separation apparatus with recovery tanks 110, 120, 130, and 140 capable of recovering sediments and the like that have undergone solid-liquid separation.
Here, since the zinc-containing precipitate has very poor filterability, the conventional zinc separator, which was required to handle a large amount of zinc-containing precipitate, settled the zinc-containing precipitate once in the gravity sedimentation separator. After that, the supernatant had to be filtered. This is because if a conventional zinc separation device is not equipped with a gravity sedimentation device, the zinc-containing sedimentation filtration efficiency will be poor and the filtration time will be lengthy. On the other hand, in the zinc separation device 80 of the recovery facility of one embodiment of the present invention, the amount of zinc-containing precipitate generated as described above can be significantly reduced. Equipment can be significantly simplified. Furthermore, the conventional zinc separator that filters the supernatant liquid has the drawback that the recovery amount of the filtrate is reduced, resulting in a decrease in the yield of the manganese component. On the other hand, in the zinc separation device 80 used in one embodiment of the present invention, it is possible to directly filter the zinc-containing precipitate from the solid-liquid mixture after the sulfide precipitation treatment step, so the yield of the manganese component is reduced. It is advantageous to raise it further.
The manganese-containing solution recovery tank 150 is preferably a tank configured so that the manganese-containing solution (fourth solution) that has been solid-liquid separated by the iron separator 100 can be recovered, stored, and discharged.

Configuration B
Further, as another aspect of the recovery equipment of the present invention, FIG. 8 shows a configuration (B) capable of suitably performing the above procedure (B). As schematically shown in FIG. 8, the recovery equipment includes a sorting device 10, a crushing device 20a, a sieving device 20b, an acid treatment tank 30, a first solid-liquid separation device 40, and an acid/reducing agent. The treatment device 50, the second solid-liquid separation device 60, the oxidation treatment tank 71, the iron separation device 81, the sulfide precipitation treatment tank 91, the zinc separation device 101, and the manganese-containing solution recovery tank 150, They can be provided in this order from upstream to downstream. Here, the oxidation treatment tank 71 and the iron separation apparatus 81 constitute an iron removal apparatus group, and the sulfide precipitation treatment tank 91 and the zinc separation apparatus 101 constitute a zinc removal apparatus group. In addition, the group of iron removal devices and the group of zinc removal devices constitute the group of manganese extraction devices.

Here, the sorting device 10, the crushing device 20a, the sieving device 20b, the acid treatment tank 30, the first solid-liquid separation device 40, the acid/reducing agent treatment tank 50, the second solid-liquid separation device 60, the iron separation device 81, zinc separator 101, recovery tanks 110, 120, 130, 140, and manganese-containing solution recovery tank 150 are all as described above for configuration A.
In particular, in the zinc separation device 101 of the recovery facility of another embodiment of the present invention, as described above for the zinc separation device 80, the filtration equipment is significantly simplified compared to the conventional technology, such as not including a gravity sedimentation separation device. can be Furthermore, as described above for the zinc separation device 80, it is possible to directly filter the zinc-containing precipitate from the solid-liquid mixture after the sulfide precipitation treatment step, so the yield of the manganese component is improved compared to the conventional technology. It is advantageous to raise it further.
The oxidation treatment tank 71 is preferably a general stirring tank equipped with a stirrer in order to oxidize the second leachate.
Further, the sulfide precipitation treatment tank 91 is preferably a general stirring tank equipped with a stirrer in order to perform the sulfide precipitation treatment in which sulfide acts on the third solution.
In the present invention, the various devices, reaction tanks, and recovery tanks that make up the recovery equipment may have any structure as long as they have the respective functions described above.

The present invention will be further described below based on examples. In addition, the following examples show a preferable example of the present invention, and do not limit the present invention in any way. In addition, the following examples can be modified within the scope of the present invention, and such aspects are also included in the technical scope of the present invention.

(Example 1)
Production of granules A sorting process for sorting out manganese dry batteries and alkaline manganese dry batteries from waste dry batteries, crushing the sorted waste dry batteries, sieving them with a sieve with an opening of 2.8 mm, and obtaining granules of waste dry batteries. A sieving step was performed to obtain a waste dry battery powder. Table 1 shows the main chemical components of the obtained granules (before the acid treatment step). In addition to the elements shown in Table 1, the obtained granules contain oxygen, a small amount of hydrogen and moisture derived from oxides or hydroxides.
Here, since the results of the chemical components in the granular material before the acid treatment step were the same between Experiment (A) and Example 1, both results are shown in Table 1.

Acid Treatment Step The powdery particles thus obtained were put into an acid treatment tank 30 and subjected to an acid treatment step. In the acid treatment step, 30 g of the powder was mixed with 300 mL of an acid solution to leach out mainly the zinc component from the powder. The acid concentration of the acid solution was sulfuric acid concentration: 2N (concentration in mass %: about 8.7%). The acid leaching treatment time (stirring time) was 1 hour, and the acid leaching treatment was performed with stirring at room temperature. In this case, the solid-liquid ratio, which is the ratio of the powder and the acid solution, was 100 g/L.

First Solid-Liquid Separation Step After the acid treatment step, the obtained mixture of the first leachate and the first leach residue is charged into the first solid-liquid separator 40 and filtered through a filter paper with a pore size of 1 μm to solidify. Liquid separation occurred. The manganese concentration, zinc concentration, and iron concentration (% by mass) in the obtained first leaching residue were quantified by ICP emission spectrometry. The results are also shown in Table 1.
Here, both the results of Experiment (A) and Example 1 are listed in Table 1 because the results of the chemical components in the first leaching residue after the acid treatment step were the same.

Acid/reducing agent treatment process The first leaching residue obtained in the first solid-liquid separation process, 2N (mass% concentration of about 8.7%) sulfuric acid as an acid solution, and 30% hydrogen peroxide water as a reducing agent. was put into the acid/reducing agent treatment tank 50 and stirred for 1 hour. The solid-liquid ratio (first leaching residue/acid solution) was 50 g/L.

Second Solid-Liquid Separation Step The obtained mixture of the second leachate and the second leach residue was charged into the second solid-liquid separator 60 and filtered through a filter paper with a pore size of 1 μm for solid-liquid separation. The manganese concentration, zinc concentration, and iron concentration (mg/L) in the second leachate obtained after the second solid-liquid separation step were quantified by ICP emission spectrometry. The obtained results are shown in the column of "Second leachate after second solid-liquid separation step" in Table 2.

Preparation of the third solution (zinc removal step)
Next, the second leachate obtained by the second solid-liquid separation step is charged into the sulfide precipitation treatment tank 70, and a sulfide precipitation treatment is performed in which sulfide acts on the zinc component still remaining in the second leachate. did the process. In the sulfide precipitation treatment step, sodium hydrosulfide NaHS as a sulfide was added to the second leachate so that the amount of sulfur S would be 2 equivalents with respect to the dissolved zinc. Note that sodium hydrosulfide was added in the form of a solution dissolved in distilled water. Also, the pH of the second leachate during the sulfide precipitation treatment was adjusted to 4 with a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide). The sulfide precipitation treatment was performed for 30 minutes with stirring.

The mixture after the above-mentioned sulfide precipitation treatment step is charged into the zinc separation device 80, subjected to a zinc separation step of performing solid-liquid separation by suction filtration with a filter paper having a pore size of 1 μm, and separated into a third solution and a zinc-containing precipitate. did. Here, the filtration time, which took about 35 minutes in the conventional zinc separation process, was shortened to about 20 minutes in the zinc separation process of the present embodiment, in which the granular material was previously subjected to the acid treatment process. Then, the components of the obtained third solution were quantitatively analyzed by ICP emission spectrometry. The amounts of sodium hydrosulfide solution and pH adjuster added were recorded, and the influence of dilution with these solutions was corrected from the analytical values. The obtained results are also shown in the column of "third solution after zinc removal step" in Table 2.

Preparation of fourth solution (iron removal step)
Next, the third solution obtained through the zinc removal step was charged into the oxidation treatment tank 90 and subjected to an oxidation treatment step of performing an oxidation reaction. In the oxidation treatment step, as the oxidation treatment, first, the obtained third solution was subjected to air aeration. The conditions for air aeration were blowing amount: (the same volume as the amount of the third solution)/minute, and aeration time: 30 minutes. After air aeration, the intermediate solution was suction-filtered through a filter paper with a pore size of 1 μm, and the contained components were quantitatively analyzed by the above method. The obtained results are also shown in the column of "intermediate solution after oxidation treatment" in Table 2.

Then, as a further oxidation treatment, an oxidizing agent was immediately added to the third solution after the air aeration. In the addition of the oxidizing agent, after adjusting the pH of the third solution by adding a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide), hydrogen peroxide solution is added as an oxidizing agent. About 8 to 16 mL was added so that the reduction potential was 550 mV or higher. In this way, the iron component in the third solution was precipitated as iron hydroxide and made removable. The treatment time with the oxidizing agent was 30 minutes.

The mixture after the oxidation treatment step by air aeration and addition of an oxidizing agent is charged into the iron separation device 100, suction filtered through a filter paper with a pore size of 1 μm, and solid-liquid separated into a manganese-containing solution (fourth solution) and an iron-containing precipitate. An iron separation process was applied.
The components contained in the obtained fourth solution were quantitatively analyzed by the above method. The amounts of hydrogen peroxide solution and pH adjuster added were recorded, and the influence of dilution with these solutions was corrected from the analytical values. The obtained results are also shown in the column of "fourth solution after iron removal step" in Table 2.

From Table 2, according to procedure A, which is one embodiment of the manganese recovery method of the present invention, the zinc component and iron component other than the manganese component contained in the waste dry battery can be easily reduced to below the analysis limit (0.1 mg / L). can be separated and removed. As described above, according to the present invention, the manganese component contained in waste dry batteries can be easily and efficiently recovered as a solution containing high-purity manganese ions.

(Example 2)
Granules were produced in the same manner as in Example 1, and the granules having the composition shown in Table 1 were obtained. In addition, when the acid treatment step, the first solid-liquid separation step, the acid/reducing agent treatment step and the second solid-liquid separation step were performed in the same manner as in Example 1, the second solid-liquid separation step after the second solid-liquid separation step Table 3 shows the content (mg/L) of manganese, zinc and iron in the leachate.

Next, a third solution was prepared (zinc removal step) in the same manner as in Example 1. Table 3 shows the components in the third solution after the zinc removal step. The filtration time, which took about 35 minutes in the conventional zinc separation process, was shortened to about 20 minutes in the zinc separation process of the present embodiment, in which the granular material was previously subjected to the acid treatment process.

Next, the third solution obtained through the zinc separation step was left at room temperature for one week and then charged into the oxidation treatment tank 90 to carry out the oxidation treatment step of performing an oxidation reaction. In the oxidation treatment step, the third solution after standing was only subjected to air aeration as oxidation treatment. The conditions for air aeration were blowing amount: (the same volume as the amount of the third solution)/minute, and aeration time: 30 minutes. After air aeration, the manganese-containing solution (fourth solution) was subjected to suction filtration through a filter paper with a pore size of 1 μm, and the contained components were quantitatively analyzed by the above method. The obtained results are also shown in the column of "Fourth solution after iron removal step" in Table 3.

From Table 3, in Procedure A, which is one embodiment of the manganese recovery method of the present invention, if the third solution separated by sulfide precipitation treatment is allowed to stand for an appropriate period of time and then subjected to an oxidation treatment step, , it can be seen that the iron component can be sufficiently separated and removed as a precipitate even by oxidation treatment only by air aeration.

(Example 3)
Granules were produced in the same manner as in Example 1, and the granules having the composition shown in Table 1 were obtained. In addition, when the acid treatment step, the first solid-liquid separation step, the acid/reducing agent treatment step and the second solid-liquid separation step were performed in the same manner as in Example 1, the second solid-liquid separation step after the second solid-liquid separation step Table 4 shows the content (mg/L) of manganese, zinc and iron in the leachate.

Preparation of the third solution (iron removal step)
Next, the second leachate separated in the second solid-liquid separation step was subjected to an oxidation treatment step. In the oxidation treatment step, the obtained second leachate is subjected to air aeration to generate iron hydroxide from the iron component contained in the second leachate, and the iron component can be separated and removed from the second leachate as an iron-containing precipitate. state. The air aeration conditions were blowing amount: (the same volume as the amount of the second leachate, mL)/minute, and aeration time: 30 minutes. Before the oxidation treatment, the pH of the second leachate was adjusted to 5 using a pH adjuster (3M sulfuric acid or 100 g/L sodium hydroxide).

After the oxidation treatment, the third solution and the iron-containing precipitate were suction filtered through a filter paper with a pore size of 1 μm to separate the third solution and the iron-containing precipitate (iron separation step). Then, the components (Mn, Zn, Fe) contained in the third solution obtained in the iron removal step were quantitatively analyzed by ICP emission spectrometry. The amount of pH adjuster added was recorded, and the measured value was corrected for the influence of dilution by the pH adjuster. The concentration (mg/L) of each component of manganese, zinc and iron in the obtained third solution is also shown in the column of "third solution after iron removal step" in Table 4.

Preparation of fourth solution (zinc removal step)
Next, sulfide is caused to act on the third solution separated in the iron separation step, mainly zinc ions still remaining in the third solution are precipitated as zinc sulfide (zinc-containing precipitate), and separated from the third solution. A sulfide precipitation treatment step was performed to make it removable. The sulfide used was sodium hydrosulfide NaHS, which was added in an amount of 2 equivalents as sulfur S to dissolved zinc. Note that sodium hydrosulfide was added in the form of a solution dissolved in distilled water. Further, the pH of the third solution during the sulfide precipitation treatment was adjusted to 4 with a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide). The sulfide precipitation treatment was performed for 30 minutes with stirring.

After the sulfide precipitation treatment, the mixture was suction-filtered through a filter paper with a pore size of 1 μm to separate into a manganese-containing solution (fourth solution) and a zinc-containing precipitate (zinc separation step). Filtration time, which used to take about 35 minutes in the conventional zinc separation process, was shortened to about 20 minutes in the zinc separation process of the present embodiment, in which the granular material was previously subjected to an acid treatment process. Then, the components of the fourth solution obtained after the separation were quantitatively analyzed by ICP emission spectrometry. The amounts of sodium hydrosulfide solution and pH adjuster added were recorded, and the measured values were corrected for the effects of dilution with these solutions. The obtained results are also shown in the column of "fourth solution after zinc removal step" in Table 4.

From Table 4, according to Procedure B, which is one embodiment of the manganese recovery method of the present invention, zinc and iron components other than manganese components contained in waste dry batteries can be easily reduced to below the analysis limit (0.1 mg / L). It can be seen that they can be separated and removed. As described above, according to the present invention, the manganese component contained in waste dry batteries can be easily and efficiently recovered as a highly pure manganese ion-containing solution with a high yield.

10 Sorting device 20a Crushing device 20b Screening device 30 Acid treatment tank 40 First solid-liquid separation device 50 Acid/reducing agent treatment tank 60 Second solid-liquid separation device 70 Sulfide precipitation treatment tank (configuration A)
71 oxidation treatment tank (configuration B)
80 zinc separator (configuration A)
81 iron separator (configuration B)
90 oxidation treatment tank (configuration A)
91 sulfide sedimentation treatment tank (configuration B)
100 iron separator (configuration A)
101 zinc separator (configuration B)
110 recovery tank 120 recovery tank 130 recovery tank 140 recovery tank 150 manganese-containing solution recovery tank

Claims (13)

A sorting step of sorting out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing and sieving step of crushing and sieving one or both of the manganese dry battery and the alkaline manganese dry battery selected in the sorting step to obtain powders;
an acid treatment step of mixing an acid solution with the granular material obtained in the crushing and sieving step to obtain a first leachate and a first leach residue;
a first solid-liquid separation step of separating the first leachate obtained in the acid treatment step and the first leach residue;
an acid/reducing agent treatment step of mixing the first leaching residue separated in the first solid-liquid separation step with an acid solution and a reducing agent to obtain a second leaching solution and a second leaching residue;
a second solid-liquid separation step of separating the second leachate obtained in the acid/reducing agent treatment step and the second leach residue;
Of the zinc ions, iron ions, and manganese ions contained in the second leachate, the zinc ions and iron ions are removed from the second leachate separated in the second solid-liquid separation step, and the manganese a manganese extraction step of obtaining a solution containing ions;
A method for recovering manganese from waste batteries by applying in this order,
The manganese extraction step is
a zinc removal step including a sulfide precipitation treatment step of reacting the zinc ions with sulfide to precipitate the zinc ions, and a zinc separation step of separating the obtained zinc-containing precipitate;
an iron removal step comprising an oxidation treatment step of oxidizing the iron ions to precipitate the iron ions, and an iron separation step of separating the resulting iron-containing precipitate;
A method for recovering manganese from waste dry batteries, comprising obtaining a manganese-containing solution by including in random order. The waste dry battery according to claim 1, wherein the acid solution in the acid treatment step is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. method for recovering manganese from 3. The method for recovering manganese from waste dry batteries according to claim 1, wherein the solid-liquid ratio of said powder and said acid solution in said acid treatment step is 50 g/L or more. Claims 1 to 3, wherein the acid solution in the acid/reducing agent treatment step is dilute sulfuric acid with a mass% concentration of 1.4% or more and 45% or less or dilute hydrochloric acid with a mass% concentration of 1% or more and 14% or less. The method for recovering manganese from waste dry batteries according to any one of 1. 5. The reducing agent in the acid/reducing agent treatment step is any one of hydrogen peroxide, sodium sulfide, sodium hydrogen sulfite, sodium thiosulfate, and iron sulfate, according to any one of claims 1 to 4. 1. A method for recovering manganese from a waste dry battery according to item 1. The manganese extraction step is performed in the order of the zinc removal step and then the iron removal step,
In the zinc removal step, the second leachate is subjected to a sulfide precipitation treatment step of causing sulfide to act on the second leachate to precipitate zinc ions in the second leachate. Performing a zinc separation step for solid-liquid separation from the third solution containing ions,
In the iron-removing step, after performing an oxidation treatment step of oxidizing the third solution obtained in the zinc-removing step to precipitate iron ions in the third solution, the resulting iron-containing precipitate and manganese 6. The method for recovering manganese from waste dry batteries according to any one of claims 1 to 5, wherein an iron separation step of solid-liquid separation from the fourth solution containing ions is performed. 7. The method for recovering manganese from waste dry batteries according to claim 6, wherein in said sulfide precipitation treatment step, said second leachate is adjusted to a pH of 2 or more and 6 or less. In the oxidation treatment step, the third solution containing manganese ions and iron ions is aerated with air, or an oxidizing agent is added to the third solution, and the third solution is adjusted to pH:3. 8. The method for recovering manganese from waste dry batteries according to claim 6 or 7, wherein the adjustment is made to 7 or less. The manganese extraction step is performed in the order of the iron removal step and then the zinc removal step,
In the iron removal step, the second leachate is subjected to an oxidation treatment step of oxidizing the second leachate to precipitate iron ions in the second leachate. 3 subjected to an iron separation process for solid-liquid separation from the solution,
In the zinc removal step, the third solution obtained in the iron removal step is subjected to a sulfide precipitation treatment step of causing sulfide to act on the third solution to precipitate zinc ions in the third solution. 6. The method for recovering manganese from waste dry batteries according to any one of claims 1 to 5, characterized by performing a zinc separation step of solid-liquid separation of the contained precipitate and the fourth solution containing manganese ions. 10. The method for recovering manganese from waste dry batteries according to claim 9, wherein in said sulfide precipitation treatment step, said third solution containing manganese ions and zinc ions is adjusted to a pH of 2 or more and 6 or less. 11. The waste dry battery according to claim 9 or 10, wherein in the oxidation treatment step, the second leachate is aerated with air, and the pH of the second leachate is adjusted to 3 or more and 7 or less. of manganese recovery method. The waste dry battery according to any one of claims 1 to 11, wherein the sulfide used in the sulfide precipitation treatment step is any one of sodium hydrosulfide, sodium sulfide, and hydrogen sulfide. method for recovering manganese from a sorting device for sorting out one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing device for obtaining a crushed product by inserting one or both of the manganese dry batteries and alkaline manganese dry batteries sorted by the sorting device and subjecting them to crushing treatment;
a sieving device for obtaining powder by sieving the crushed material obtained by the crushing device;
an acid treatment tank for acid-treating the granular material obtained by the sieving device;
a first solid-liquid separator for separating the first leachate obtained in the acid treatment tank from the first leach residue;
an acid/reducing agent treatment tank in which an acid solution and a reducing agent are applied to the first leaching residue separated by the first solid-liquid separation device;
a second solid-liquid separator for separating the second leachate obtained in the acid/reducing agent treatment tank from the second leach residue;
Of the zinc ions, iron ions, and manganese ions contained in the second leachate, the zinc ions and iron ions are removed from the second leachate separated by the second solid-liquid separator, and the manganese a group of manganese extractors for obtaining a solution containing ions;
Manganese recovery equipment from waste dry batteries, comprising in this order,
The manganese extraction device group
a group of zinc removal devices including a sulfide precipitation treatment tank for causing sulfide to act on the zinc ions to precipitate the zinc ions;
an iron removal device group including an oxidation treatment tank for oxidizing the iron ions to precipitate the iron ions, and an iron separation device for solid-liquid separation of the obtained iron-containing precipitate;
Manganese recovery equipment from waste dry batteries, characterized in that a manganese-containing solution is obtained by including in random order.

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