WO2023238447A1 - Recovery method and recovery facility for manganese contained in waste dry battery - Google Patents

Abstract

According to the present invention, a high-purity manganese-containing solution is recovered with high yield from a waste dry battery.　In this recovery method for manganese contained in a waste dry battery, the following steps are performed in the stated order: a selection step in which manganese dry batteries and/or alkaline manganese dry batteries are selected from waste dry batteries; a crushing and screening step in which crushing and screening are performed to obtain granules; an acid leaching step in which a leachate that contains manganese ions, zinc ions, and iron ions is obtained; a solid/liquid separation step in which the leachate and other leaching residue are separated from one another; and a manganese extraction step in which a solution that contains manganese ions is obtained. The manganese extraction step includes, in no particular order: a zinc removal step that includes a sulfide precipitation processing step and a zinc separation step; and an iron removal step that includes an oxidation processing step and an iron separation step. In the zinc separation step, a sulfurizing agent is made to act so that the change in pH following addition of the sulfurizing agent is +1 or less.

Description

Recovery method and recovery equipment for manganese contained in waste dry batteries

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 main valuable component of the waste dry battery, after treating the waste manganese dry battery and/or alkaline manganese dry battery with an acid and an oxidizing agent. The present invention also relates to a method and equipment for recovering manganese contained in waste dry batteries, which can be recovered as high-purity manganese that can be used for various batteries.

In recent years, due to the depletion of metal resources and the rise in transaction prices, it has become necessary to actively recover valuable metals from low-grade raw ores, concentrates, steel mill by-products, industrial waste, etc. For example, manganese, which is one of the valuable metals, is considered an essential metal in a wide variety of industrial fields, and there are concerns that its demand will exceed reserves in the future. Steelworks consume large amounts of manganese as a raw material for steelmaking, and securing manganese sources is an extremely important issue in the steelmaking field. Furthermore, in recent years, the consumption of manganese for secondary batteries such as lithium ion batteries has increased, and securing a manganese source has become an extremely serious problem in the field of secondary batteries as well.

On the other hand, in Japan, huge amounts of dry batteries are produced, consumed, and disposed of and discarded as industrial waste. Some dry batteries (used dry batteries) that are discarded as industrial waste 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.

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

However, in addition to manganese, waste batteries also contain metal components such as zinc and iron. Zinc is mainly contained in the negative electrode material and electrolyte. Iron is mainly contained in the outer cylindrical part of the dry battery. Therefore, when recovering manganese from waste dry batteries, it is important to separate metal components such as zinc and iron from manganese as much as possible.

The inventors studied a technology for separating zinc and iron from waste dry batteries and recovering manganese with high purity, and proposed Patent Document 1, "Manganese recovery method and recovery equipment from waste dry batteries." As shown in Figure 1, the proposal in Patent Document 1 is to perform acid leaching by mixing an acid solution and a reducing agent with the powder obtained by crushing and sieving waste dry batteries, and then precipitate and remove zinc and iron. This is a method to obtain highly pure manganese.

However, in order to remove zinc in the method shown in Patent Document 1, it is necessary to add an excess of the sulfiding agent relative to the amount of zinc ions in the liquid. Therefore, it was necessary to measure the amount of zinc in the solution in advance, and it became clear that the operation was complicated. Further, the surplus sulfurizing agent (the sulfurizing agent that did not react with zinc) may react with protons (H ⁺ ) in the water to generate undesirable hydrogen sulfide gas.

By the way, as a method for suppressing the generation of hydrogen sulfide gas by reacting a sulfurizing agent with heavy metal ions in a solution in just the right amount, there is a method disclosed in Patent Document 2, for example. Patent Document 2 describes that a hydrogen sulfide gas monitor is installed in a heavy metal wastewater treatment device, and a sulfiding agent is added to maintain a state in which hydrogen sulfide gas starts to be generated from the wastewater.

International Publication No. 2021/075135 International Publication No. 2003/020647

The method of Patent Document 1 requires equipment to detoxify hydrogen sulfide gas (scrubber, etc.), and has the problem of increasing equipment investment.

In the method of Patent Document 2, a time lag occurs between the generation of hydrogen sulfide gas and the detection by the gas monitor. Therefore, the problem was that it was difficult to precisely control the amount of sulfurizing agent added. Furthermore, depending on the shape of the reaction tank or the piping of the exhaust system, there is a possibility that a "gas pool" with a locally high concentration of hydrogen sulfide may form. If the amount of sulfiding agent added was determined based on the hydrogen sulfide concentration, there was a risk that the amount to be added would be lower than the originally necessary amount if a gas pocket was formed, and there was a risk that metals would not be removed sufficiently.

The present invention has been made in view of the above problems, and allows the manganese contained in waste dry batteries to be recovered with high yield as a high-purity manganese-containing solution with extremely low levels of zinc and iron contamination, and without the use of sulfurizing agents. The purpose of the present invention is to provide a method and equipment for recovering manganese from waste dry batteries, which reacts with zinc ions in a solution in just the right amount and suppresses the generation of hydrogen sulfide gas.

Here, "high purity manganese-containing solution" means that the impurities zinc (Zn) and iron (Fe) in the solution are both within the analysis limit when analyzed using the analysis method specified in the commonly used JIS standard. 0.1 mg/L, such as less than 0.1 mg/L.

When manganese dry batteries and/or alkaline manganese dry batteries are sorted from waste dry batteries, crushed and sieved, the materials constituting the dry batteries are separated into solids on the sieve and powder particles below the sieve. Among the materials constituting dry batteries, mainly iron shell packaging materials, zinc cans, brass rods, paper materials, plastics, etc. are crushed into foil-like or flake-like solids, which are separated on a sieve. On the other hand, manganese dioxide, carbon, zinc chloride, ammonium chloride, potassium hydroxide, or MnO(OH), Zn(OH) ₂ , Mn(OH) ₂ , ZnO, etc. generated by electric discharge become powder and granules and fall under the sieve. separated into Here, normally, a trace amount of iron is inevitably mixed into the powder or granular material.

In order to achieve the above-mentioned objective, the present inventors have intensively studied an impurity separation means that is effective for recovering manganese contained in waste dry batteries as a highly pure manganese-containing solution with few impurities. In particular, the present inventors have investigated how to remove unintended components (impurities) from the powder obtained by sorting one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries, and further crushing and sieving them. We seriously considered whether to remove it. In addition, the present inventors have conducted extensive studies on a method for adding just the right amount of sulfurizing agent needed to remove zinc, which is contained in the zinc in the second largest amount after manganese.

As a result, the present inventors obtained a leachate in which iron and remaining manganese and zinc were leached out by applying an acid and a reducing agent to the granular material. The idea was to add the agent only while the pH change of the exudate was below +1. As a result, we have come up with the idea that it is possible to selectively precipitate the zinc ions remaining in the leachate as sulfides (zinc-containing sulfides) while adding just the right amount of sulfiding agent (sulfide precipitation treatment step). Furthermore, the present inventors have discovered that the zinc component can be further removed from the leachate by performing a zinc separation step in which the obtained zinc-containing precipitate is separated. The present inventors have also discovered that the zinc ion concentration in the solution left after the zinc removal step can be easily reduced to less than 0.1 mg/L, which is the analytical limit.

In the sulfide precipitation treatment process, the following reactions occur. The case where the sulfiding agent is NaHS will be explained as an example.

Case 1: Zinc ion molar equivalent ≧ sulfurizing agent molar equivalent (sulfurizing agent insufficient to equal amount)
NaHS → Na ⁺ + HS ^- (1)
HS ^- →H ⁺ + S ^2-... (2)
Zn ²⁺ + S ^2- →ZnS↓・・・(3)
In formula (2), since protons (H ⁺ ) are generated, the pH of the leachate is lowered by adding the sulfurizing agent.

Case 2: Zinc ion molar equivalent < sulfurizing agent molar equivalent (sulfurizing agent excess)
NaHS→Na ⁺ + HS ^-・・・(4)
HS ^- + _H2O → _H2S ↑+OH ^-... (5)
In formula (5), since hydroxide ions (OH ⁻ ) are generated, the pH of the leachate increases by adding the sulfurizing agent, and hydrogen sulfide is generated.

That is, by adding the sulfurizing agent only while the pH change of the leachate when the sulfurizing agent is added is +1 or less, it is possible to add just the right amount of sulfurizing agent and suppress the generation of hydrogen sulfide.

As Procedure A2, which is a more specific embodiment, the present inventors performed the following steps. First, a sulfurizing agent such as sodium hydrosulfide, NaHS, was applied to the leachate only while the pH change of the leachate was +1 or less. As a result, a sulfide precipitation treatment step is performed in which zinc ions remaining in the leachate are selectively precipitated as sulfides (zinc-containing sulfides). Then, by performing a zinc separation step of separating the obtained zinc-containing precipitate, the zinc component can be further removed from the leachate (zinc removal step in procedure A2). It was confirmed that these steps could easily reduce the zinc ion concentration in the solution left after the zinc removal step to less than the analytical limit of 0.1 mg/L. In addition, if this solution is then further subjected to an oxidation treatment process and the iron ions are further separated as iron-containing precipitates (iron separation process), a high-purity manganese solution can be easily prepared as the solution remaining after the iron component is separated. It was also confirmed that it could be obtained with a high yield (iron removal step in procedure A2).

Furthermore, as another specific embodiment of Procedure B, the present inventors performed the following steps. First, by oxidizing the leachate with air, for example, iron ions contained in the leachate are selectively precipitated as, for example, hydroxide, and only iron components are preferentially separated from the leachate. It was confirmed that the iron ion concentration in the solution left after the separation of iron components could be significantly reduced (iron removal step in procedure B). Thereafter, this solution is subjected to a sulfide precipitation treatment in which a sulfurizing agent such as sodium hydrosulfide (NaHS) is applied only while the pH change of the leachate is below +1, whereby the remaining zinc ions are further separated as a zinc-containing precipitate. Ta. This confirmed that a highly pure manganese solution could be easily obtained with a high yield as the solution left after separation (zinc removal step in procedure B).

The results of experiment (A1), experiment (A2), and experiment (B) conducted by the present inventors according to each of the above procedures will be explained.

(Experiment (A1))
Manganese dry batteries and alkaline manganese dry batteries were sorted out from the waste dry batteries (sorting step), and then subjected to a crushing and sieving step to obtain powder.

The obtained powder was subjected to an acid leaching treatment in which an acid solution and a hydrogen peroxide solution H ₂ O ₂ were mixed as a reducing agent to leach manganese, zinc, and iron from the powder (acid leaching). process). Here, the acid concentration of the acid solution in the acid leaching step is sulfuric acid concentration: 2N (mass% concentration approximately 9.0%), the amount of hydrogen peroxide H ₂ O ₂ added is 45 g/L, and the acid leaching treatment time is The stirring process was performed for 1 hour. Through this acid leaching process, a mixture of a leaching solution containing at least manganese ions, zinc ions, and iron ions and other leaching residues was obtained.

After the acid leaching step, the resulting mixture was suction-filtered through a filter paper with a pore size of 1 μm, and the leachate and the leaching residue were solid-liquid separated (solid-liquid separation step). When the manganese concentration, zinc concentration, and iron concentration in the separated leachate were measured by ICP emission spectrometry, the manganese concentration was 30,000 mg/L, the zinc concentration was 16,500 mg/L, and the iron concentration was 380 mg/L.

Next, the obtained leachate was subjected to a sulfide precipitation treatment step in which sodium hydrosulfide, NaHS, was added as a sulfurizing agent under various conditions. Here, 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.
Leachate: 100mL
Type of sulfurizing agent: Sodium hydrosulfide (NaHS)
Addition amount of sulfurizing agent: 1 to 3 equivalents of sulfur to dissolved zinc pH of leachate during reaction: 0.5 to 5
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide Treatment time: 0.5 hour stirring after addition of sodium hydrosulfide

After the sulfide precipitation treatment, solid-liquid separation is performed by suction filtration through a filter paper with a pore size of 1 μm (zinc separation step), and the components (zinc, iron, manganese) of the separated second solution are quantified by ICP emission spectrometry. Analyzed. Here, the obtained analytical values were corrected for the influence of dilution by the addition of sodium hydrosulfide solution and pH adjuster. Figures 5A-5C show the results obtained.

From FIG. 5A, when the amount of the sulfiding agent added is 1 equivalent (NaHS: 1 equivalent), although zinc precipitation is removed, it exceeds the analytical limit (0.1 mg/L) and is incomplete. Furthermore, it can be seen that the final Zn removal rate is not stable when the pH of the leachate is increased.

On the other hand, as shown in FIG. 5B, when the amount of the sulfurizing agent added was 2 equivalents (NaHS: 2 equivalents), the precipitation and removal of zinc became remarkable. In particular, under conditions where the pH of the leachate is 3 or more, the zinc concentration in the second solution after the zinc removal process (sulfide precipitation treatment process and zinc separation process) becomes less than the analytical limit (0.1 mg/L). You can see that it has been removed. Furthermore, even when the amount of sulfiding agent added is 3 equivalents (NaHS: 3 equivalents) as shown in Figure 5C, the same tendency as in the case of 2 equivalents is shown, and especially when the pH of the leachate is 3 or more, the zinc concentration is It was below the analysis limit (0.1 mg/L), and the removal of zinc by precipitation was significant.

Here, from FIGS. 5A to 5C, it can be seen that iron precipitation is also removed in the zinc removal process. As shown in Figure 5B, when the amount of the sulfiding agent added is 2 equivalents (NaHS: 2 equivalents), iron is precipitated and removed under the condition that the pH of the leachate is 3 or more, and when the pH is about 5, Fe is removed. It can be seen that the concentration is reduced to about 1 mg/L. Under these conditions shown in FIG. 5B, although not shown, the manganese concentration also began to decrease to about 24,000 mg/L. In other words, it can be seen that under conditions where the amount of sulfiding agent added is 2 equivalents and the pH is 3 or higher, a portion of manganese is also precipitated and removed at the same time as zinc and iron.

Furthermore, it can be seen that even when the amount of the sulfiding agent added is 3 equivalents (NaHS: 3 equivalents) as shown in FIG. 5C, iron is precipitated and removed with the same tendency as in the case of 2 equivalents. As shown in FIG. 5C, it can be seen that when the pH of the leachate is 5, the precipitation and removal of iron becomes particularly remarkable, and iron is removed until it becomes less than 0.1 mg/L. However, although not shown in the figure, when the pH was 5 in FIG. 5C, the manganese concentration decreased significantly, and more than 30% of manganese was precipitated and removed. In other words, it can be seen that under conditions where the amount of sulfurizing agent added is 3 equivalents and the pH exceeds 3, not only zinc is removed, but also iron and manganese are precipitated in larger amounts than when the amount of sulfurizing agent added is 2 equivalents. .

As described above regarding experiment (A1), according to the sulfide precipitation treatment step for the leachate containing manganese ions, iron ions, and zinc ions, the zinc component can be precipitated and separated to a level below the analytical limit. However, during this experiment, a rotten egg odor suggesting the generation of hydrogen sulfide gas was observed. When the hydrogen sulfide gas concentration was measured, it was found to be 3.1 ppm at maximum. This concentration exceeds the control concentration (1 ppm) for hydrogen sulfide, and improvements are required. Therefore, in experiment (A2), the relationship between the amount of sulfurizing agent added and the concentration of hydrogen sulfide was investigated, and a method of controlling the amount of sulfurizing agent added while minimizing the amount of hydrogen sulfide gas generated was studied.

(Experiment (A2))
According to the same method as in Experiment (A1), the manganese concentration, zinc concentration, and iron concentration in the leachate separated by the solid-liquid separation step were measured by ICP emission spectrometry. The manganese concentration was 30,000 mg/L, the zinc concentration was 16,500 mg/L, and the iron concentration was 380 mg/L.

Next, sodium hydroxide was added to the obtained leachate to adjust the pH to 4, and then a sulfiding agent was added in an amount of 0.1 equivalent to zinc, and the pH and hydrogen sulfide concentration were measured. The control pH was set to 4, and when the pH was lower than the control pH, 100 g/L sodium hydroxide aqueous solution was added, and when the pH was higher than the control pH, 3M sulfuric acid was added, and the pH became 4. After checking, the sulfiding agent was added.

Figure 6 shows the correlation between the amount of sulfurizing agent added, pH, and hydrogen sulfide concentration. When the amount of the sulfurizing agent added was 1 equivalent or less, the pH decreased after the addition of the sulfurizing agent, and the hydrogen sulfide gas concentration was 0. On the other hand, when the amount of the sulfurizing agent added exceeds 1 equivalent, the pH increased after the addition of the sulfurizing agent, and as the amount added increased, the hydrogen sulfide gas concentration increased. That is, it was considered possible to determine the end point of the sulfide precipitation reaction by observing the pH change after addition of the sulfurizing agent.

As a result of measuring the zinc concentration in the second solution when the amount of sulfurizing agent added was 1.1 equivalent, it was found that zinc was reduced to below the analysis limit (0.1 mg/L). At this time, the hydrogen sulfide gas concentration was 0.05 ppm, which was found to be lower than the controlled concentration of hydrogen sulfide (1 ppm). Therefore, compared to experiment (A1), it was found that the amount of hydrogen sulfide gas generated could be suppressed and zinc could be removed under safer treatment conditions.

As described above regarding experiment (A2), according to the sulfide precipitation treatment process for the leachate containing manganese ions, iron ions, and zinc ions, the zinc component can be precipitated and separated to a level below the analytical limit. . In addition, some iron (Fe) may also precipitate together with zinc (Zn). If the iron (Fe) concentration has been precipitated and removed to a certain extent, it is possible to terminate the treatment at this stage. However, in order to remove iron to a higher degree, an iron removal step (oxidation treatment step and process) was further applied.

(Experiment (B))
According to the same method as in experiment (A2), the manganese concentration, zinc concentration, and iron concentration in the leachate separated by the solid-liquid separation step were measured by ICP emission spectrometry. The manganese concentration was 30,000 mg/L, the zinc concentration was 16,500 mg/L, and the iron concentration was 380 mg/L.

Then, the obtained leachate was subjected to air aeration as an oxidation treatment (oxidation treatment step). The conditions for air aeration were as follows.
Blow amount: (same volume as leachate amount)/min Aeration time: 30 minutes pH of leachate during reaction: 4 to 6
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide

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

Then, the entire amount of leachate after air aeration is suction 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 determined by ICP emission spectrometry. was measured. Here, the obtained measured values were corrected for the influence of dilution with the pH adjuster. Figure 7 shows the results obtained. Since almost no precipitation of manganese and zinc was observed during the oxidation process, FIG. 7 shows only the iron concentration in the solution after the iron removal process (oxidation process and iron separation process).

From FIG. 7, it can be seen that Fe (iron) is selectively precipitated and removed when the leachate has a pH of 4 to 6. Although not shown in the figure, 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 10 to 20 mg/L. . When the pH of the leachate is 5 or 6, the precipitation and removal of iron progresses significantly, and the iron concentration is reduced to below 0.1 mg/L. In this way, the iron concentration could be significantly reduced simply by subjecting the leachate to air aeration, which is an inexpensive oxidation treatment.

In Figure 7, the leachate adjusted to pH: 5 is subjected to air aeration (oxidation treatment) to reduce the iron concentration to less than 0.1 mg/L, and the solution obtained by performing an iron separation process by solid-liquid separation. On the other hand, a sulfide precipitation treatment step was further performed under various conditions.

The conditions for the sulfide precipitation treatment were as follows.
Third solution: 100mL
Type of sulfurizing agent: Sodium hydrosulfide (NaHS)
Amount of sulfiding agent added: 1.1 equivalents of sulfur to dissolved zinc (same as experiment (A2))
pH of third solution during reaction: 4
pH adjuster: 3M sulfuric acid or 100g/L sodium hydroxide Treatment time: 0.5 hour stirring after addition of sodium hydrosulfide

After the above-described sulfide precipitation treatment step, solid-liquid separation was performed by suction filtration through a filter paper with a pore size of 1 μm (zinc separation step), and the components of the separated fourth solution were analyzed by ICP emission spectrometry.

As a result of measuring the zinc concentration in the fourth solution, it was found that zinc was reduced to below the analysis limit (0.1 mg/L). At this time, the hydrogen sulfide gas concentration was 0.2 ppm, which was found to be lower than the controlled concentration of hydrogen sulfide (1 ppm). Therefore, it was found that zinc could be removed to below the analysis limit while suppressing the amount of hydrogen sulfide gas generated.

Regarding experiment (B), as described above, a simple oxidation treatment called air aeration is applied to the leachate in which manganese, zinc, and iron have entered, which is obtained by mixing the powder of waste dry batteries with an acid solution and a reducing agent. By doing so, it is possible to obtain a solution in which most of the iron components are precipitated and separated and removed (iron removal step). Then, if a sulfide precipitation treatment step is performed in which a sulfurizing agent is applied to the separated fourth solution, the amount of zinc-containing precipitate is reduced, so that the zinc component can be precipitated and removed below the analysis limit ( zinc removal process).

In this way, according to experiments (A2) and (B), both zinc and iron could be reliably and easily precipitated and separated and removed by going through the zinc removal process and iron removal process, regardless of the order of the processes. A highly pure manganese-containing solution can be produced. Furthermore, it has been found that zinc can be removed while suppressing the amount of hydrogen sulfide gas generated by adding the sulfurizing agent only while the pH change is +1 or less when adding the sulfurizing agent in the zinc removal process.

The present invention has been completed through further study based on this knowledge. That is, the gist of the present invention is as follows.

(1) A sorting step of sorting one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing and sieving step for obtaining powder and granular material by crushing and sieving one or both of the manganese dry batteries and alkaline manganese dry batteries sorted in the sorting step;
Acid leaching to obtain a leachate containing manganese ions, zinc ions, and iron ions contained in the powder by mixing an acid solution and a reducing agent with the powder obtained in the crushing and sieving step. process and
a solid-liquid separation step of separating the leachate obtained in the acid leaching step from other leaching residue;
a manganese extraction step of removing the zinc ions and iron ions from the leachate separated in the solid-liquid separation step to obtain a solution containing the manganese ions;
in this order,
The manganese extraction step is
a zinc removal step including a sulfide precipitation treatment step of causing a sulfiding agent to act on the zinc ions to precipitate the zinc ions; and a zinc separation step of separating the obtained zinc-containing precipitate;
an iron removal step including an oxidation treatment step of oxidizing the iron ions to precipitate the iron ions, and an iron separation step of separating the obtained iron-containing precipitate;
In no particular order,
A method for recovering manganese contained in waste dry batteries, in which a sulfurizing agent is applied only while the pH change after addition of the sulfurizing agent is +1 or less in the zinc separation step.

(2) In (1), the manganese extraction step is performed in the order of the zinc removal step and the iron removal step,
In the zinc removal step, after performing a sulfide precipitation treatment in which a sulfiding agent is applied to the leachate to precipitate zinc ions in the leachate, the zinc-containing precipitate and manganese ions obtained in the sulfide precipitation treatment step are removed. and a first solution containing iron ions are subjected to solid-liquid separation,
In the iron removal step, the first solution obtained in the zinc removal step is subjected to an oxidation treatment to precipitate iron ions in the first solution, and then the iron-containing solution obtained in the oxidation treatment step is 1. A method for recovering manganese contained in waste dry batteries, the method comprising solid-liquid separation of a second solution containing manganese ions.

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

(4) In (2) or (3), in the oxidation treatment step, air aeration is performed on the first solution containing manganese ions and iron ions, or an oxidizing agent is further added to the first solution. and adjusting the pH of the first solution to be 3 or more and 7 or less.

(5) In (1), 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, after performing an oxidation treatment step of oxidizing the leachate to precipitate iron ions in the leachate, the obtained iron-containing precipitate and a third solution containing manganese ions and zinc ions are combined. An iron separation process is applied to solid-liquid separation,
In the zinc removal step, a sulfide precipitation treatment step is performed in which the third solution obtained in the iron removal step is treated with a sulfurizing agent to precipitate zinc ions in the third solution, and then the obtained zinc A method for recovering manganese contained in waste dry batteries, which includes performing a zinc separation step of solid-liquid separation of a contained precipitate and a fourth solution containing manganese ions.

(6) In (5), in the sulfide precipitation treatment step, the third solution containing manganese ions and zinc ions is adjusted to have a pH of 2 or more and 6 or less. Collection method.

(7) In (5) or (6), in the sulfide precipitation treatment step, the leachate is aerated with air, and the leachate is adjusted to have a pH of 3 or more and 7 or less. How to recover the manganese contained.

(8) In any one of (1) to (7), the acid solution in the acid leaching step is dilute sulfuric acid with a mass % concentration of 1.4% to 45% or a mass % concentration of 1% to 14%. A method for recovering manganese contained in waste dry batteries, characterized by using dilute hydrochloric acid.

(9) In any one of (1) to (8), the waste dry battery is characterized in that the solid-liquid ratio between the powder and granular material in the acid leaching step and the acid leaching step is 50 g/L or more. How to recover the manganese contained.

(10) In any one of (1) to (9), the reducing agent in the acid leaching step is any one of hydrogen peroxide, sodium sulfide, sodium bisulfite, sodium thiosulfate, and iron sulfate. A method for recovering manganese contained in waste dry batteries.

(11) In any one of (1) to (10), the sulfiding agent used in the sulfide precipitation treatment step is any one of sodium bisulfide, sodium sulfide, and hydrogen sulfide. , a method for recovering manganese contained in waste dry batteries.

(12) A sorting device that sorts one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing device in which one or both of the manganese dry batteries and alkaline manganese dry batteries sorted by the sorting device is charged and subjected to crushing treatment to obtain a crushed product;
a sieving device that performs a sieving process on the crushed material obtained by the crushing device to obtain a granular material;
The powder obtained by the sieving device is mixed with an acid solution and a reducing agent to leach out the manganese, zinc and iron contained in the powder, resulting in manganese ions, zinc an acid treatment tank for obtaining a leachate containing ions and iron ions;
a solid-liquid separator that separates the leachate and leach residue obtained in the acid treatment tank;
A manganese extraction device group that removes the zinc ions and iron ions from the leachate separated by the solid-liquid separator to obtain a solution containing the manganese ions;
in this order,
The manganese extraction device group is
A sulfide precipitation treatment tank that causes a sulfurization agent to act on the zinc ions to precipitate the zinc ions, a sulfide addition device that controls the amount of sulfurization agent treated according to a pH change in the sulfide precipitation treatment tank, and the obtained A zinc removal equipment group including a zinc separation equipment for solid-liquid separation of zinc-containing precipitates;
An iron removal device group including an oxidation treatment tank that oxidizes the iron ions and precipitates the iron ions, and an iron separation device that separates the obtained iron-containing precipitate into solid and liquid;
Equipment for recovering manganese contained in waste dry batteries, including in no particular order.

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

FIG. 1 is a flowchart for explaining the manganese recovery process shown in Patent Document 1. FIG. 2 is a flowchart illustrating the steps of the manganese recovery method of the present invention. FIG. 3 is a flowchart illustrating an embodiment (procedure A2) of the manganese recovery method of the present invention. FIG. 4 is a flowchart illustrating another embodiment (procedure B) of the manganese recovery method of the present invention. FIG. 5A is a graph showing the influence of the amount of sulfiding agent added (NaHS: 1 equivalent) and pH conditions on the precipitation removal of zinc, iron, and manganese in the sulfide precipitation treatment step according to the flow of FIG. 3. FIG. 5B is a graph showing the influence of the amount of sulfiding agent added (NaHS: 2 equivalents) and pH conditions on the precipitation removal of zinc, iron, and manganese in the sulfide precipitation treatment step according to the flow of FIG. 3. FIG. 5C is a graph showing the influence of the amount of sulfiding agent added (NaHS: 3 equivalents) and pH conditions on the precipitation removal of zinc, iron, and manganese in the sulfide precipitation treatment step according to the flow of FIG. 3. FIG. 6 is a graph showing the correlation between the amount of sulfurizing agent added, pH, and hydrogen sulfide gas concentration. FIG. 7 is a graph showing the influence of pH on iron precipitation removal in the oxidation treatment step according to the flow of FIG. 4. FIG. 8 is a schematic diagram illustrating an embodiment (configuration A2) of the manganese recovery equipment of the present invention. FIG. 9 is a schematic diagram illustrating another embodiment (configuration B) of the manganese recovery equipment of the present invention.

The present invention targets waste dry batteries, and separates the manganese component, which is a valuable component contained in waste dry batteries, from the zinc and iron components, which are also contained in waste dry batteries, and recovers it as a high-purity manganese-containing solution with a high yield. A method and equipment for recovering manganese. Embodiments of the present invention will be specifically described below with reference to the drawings. The following embodiments show preferred examples of the present invention, and the present invention is not limited to these examples in any way.

(Manganese recovery method)
As shown in FIG. 2, the manganese recovery method of the present invention includes, in order, a sorting step, a crushing/sieving step, an acid leaching step, a solid-liquid separation step, and a manganese extraction step. Moreover, the manganese extraction step includes a predetermined zinc removal step and iron removal step in random order. The manganese recovery method of the present invention may follow the flow shown in FIG. 3 or the flow shown in FIG. 4 depending on the order of the zinc removal step and the iron removal step.

By following the above-mentioned predetermined steps in the recovery method of the present invention, components other than manganese contained in waste dry batteries can be sequentially, reliably and easily removed. As a result, according to the recovery method of the present invention, it is possible to easily recover the manganese component from waste dry batteries with a high purity and high yield that can be used as a raw material for secondary battery electrode materials. . The recovery method of the present invention can be suitably carried out using manganese recovery equipment, which will be described later.

(Sorting process)
Waste dry batteries are generally collected in the form of a mixture of various types of dry batteries. For this reason, 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 selected from recovered waste dry batteries. In order to efficiently extract the manganese component in a later process, 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 may be used, such as manual sorting or mechanical sorting using a sorting device.

(Crushing/sieving process)
Next, the manganese dry batteries and/or alkaline manganese dry batteries selected in the sorting process are subjected to a crushing process. The purpose of crushing is to eliminate 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 sorting process. A crushed product is obtained by the crushing treatment.

When these waste dry batteries are crushed, packaging materials (iron, plastic, paper, etc.), zinc cans that are the negative electrode material of manganese dry batteries, and brass rods that are the current collectors of alkaline manganese dry batteries are solid materials in the form of foil or flakes. becomes. On the other hand, manganese dioxide, which is a positive electrode material, and carbon rods, which are current collectors in manganese dry batteries, are powder particles that are finer than foil-like or flake-like solids. Similarly, zinc powder, which is the negative electrode material of alkaline manganese dry batteries, compounds such as MnO(OH), Zn(OH) ₂ , Mn(OH) ₂ , ZnO, etc. produced by discharge, and various electrolytes are used in the form of foils or flakes. The powder becomes finer than the solid material.

A crushing device is usually used to crush waste dry batteries. The type of crushing device is not particularly limited, and for example, it is preferable to use a type that can effectively separate the solid matter such as the packaging material constituting the dry cell battery from the powder after crushing. An example of such a crushing device is a two-shaft rotary type crushing device.

The opening of the sieve used for the above-mentioned sieving of the crushed material (sieving between foil-like or flaky solids and granular material) is preferably 1 mm or more, preferably 20 mm or less, and 10 mm or less. More preferably, it is 3 mm or less. The opening of the sieve is preferably about 1 to 20 mm, more preferably about 1 to 10 mm, and even more preferably about 1 to 3 mm. If the mesh opening of the sieve is equal to or larger than the above lower limit, more powder and granules containing a manganese component can be secured. Moreover, if the opening of the sieve is below the above upper limit, solids containing unintended components other than manganese can be further removed, and subsequent steps can be carried out more efficiently.

Therefore, if waste dry batteries are crushed and then sieved using the sieve with the above-mentioned openings, large solids such as packaging materials will be removed from the waste dry batteries, and powder particles that mainly contain carbon as well as manganese and zinc components will be removed. You can get the body efficiently.

In this way, the powder obtained through the crushing and sieving process is a mixture of main constituent materials of manganese dry batteries and/or alkaline manganese dry batteries. The main constituent materials are manganese dioxide, carbon, zinc chloride or ammonium chloride, caustic potash, and furthermore, MnO(OH), Zn(OH) ₂ , Mn(OH) ₂ , ZnO, etc. generated by electric discharge. Here, iron components are usually mixed into the powder or granules.

(Acid leaching process)
In the acid leaching step, an acid solution and a reducing agent are mixed with the powder obtained in the crushing and sieving step, and the powder is subjected to the acid leaching step. Through this acid leaching step, a leaching solution is obtained in which mainly manganese components, zinc components, and further iron components are leached from the powder into the acid solution. Here, the carbon component remains as a solid leaching residue.

The acid used in the acid solution may be a general acid, such as sulfuric acid, nitric acid, hydrochloric acid, or other acids. Although it can be selected as appropriate depending on price and purpose, in consideration of cost and ease of procurement, it is preferable to use sulfuric acid or hydrochloric acid as the acid solution.

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

When using hydrochloric acid, it is preferable to use dilute hydrochloric acid having a hydrochloric acid concentration of 1% or more and 14% or less in mass % concentration. More specifically, the hydrochloric acid concentration is preferably 1% or more, more preferably 2% or more, preferably 14% or less, and more preferably 8% or less. More preferably, the hydrochloric acid is dilute hydrochloric acid with a concentration of 2% or more and 8% or less.

Any commercially available sulfuric acid or hydrochloric acid can be used, but the cost of the acid solution can be reduced by diluting industrial or industrial waste acid with few harmful metal components. Moreover, the "mass % concentration" here is the value obtained by dividing the mass of the acid in the acid solution by the mass of the entire acid solution multiplied by 100.

Here, no matter which acid solution is used, the acid concentration required for leaching the zinc component depends on the solid-liquid ratio of the powder and the acid solution, the amount of the powder, and the zinc content in the powder. , it varies depending on the form of zinc in the powder, etc. Therefore, it is preferable to determine the optimal acid concentration by conducting a preliminary experiment assuming an actual machine in advance.

In the acid leaching step of the present invention, an acid solution and a reducing agent are mixed with the powder. The reason for adding the reducing agent is to almost completely leach out the manganese component contained in the powder. The forms of manganese contained in the granular material are expected to be MnO ₂ , Mn ₂ O ₃ , MnO(OH), Mn ₃ O ₄ , Mn(OH) ₂ and the like. Of these, it is thought that only part of Mn(OH) ₂ and Mn ₃ O ₄ is dissolved by acid alone. It is believed that MnO ₂ hardly dissolves in acid. Manganese dissolves in acid when it has a valence of 2. In order to dissolve manganese with a valence of 3, 4, etc. in an acid, it takes a valence of 2. It is necessary to give back. Therefore, a reducing agent is required as a substance that supplies electrons for reduction. Here, the amount of the reducing agent added is not particularly limited, but it depends on the form of manganese contained in the powder, so about 5 to 200 g/L of the acid solution is sufficient.

As the reducing agent, any of various commonly used reducing agents can be used. Examples of the reducing agent include hydrogen peroxide _H2O2 , sodium sulfide _{Na2S.9H2O ,} sodium hydrogensulfite _{NaHSO3 , sodium} thiosulfate _{Na2S2O3 ,} and iron sulfate _{FeSO4.7H2O .} . Here, the sulfur-based reducing agent may generate corrosive gases such as sulfur dioxide gas and hydrogen sulfide gas, so care must be taken from the viewpoint of safety and the like. From this point of view, it is preferable that the reducing agent is hydrogen peroxide H ₂ O ₂ .

Here, as for the zinc component contained in the powder, if the acid concentration is increased regardless of the presence or absence of a reducing agent, almost the entire amount will be dissolved (leached).

In addition, from the perspective of improving the efficiency of acid leaching treatment, the solid-liquid ratio between the powder and acid solution (powder (g)/acid solution (L)) in the acid leaching process is set to 50 g/L or more. It is preferable. On the other hand, if the solid-liquid ratio exceeds 800 g/L, the viscosity may increase and handling problems may occur, or the yield during the solid-liquid separation step may deteriorate. For this reason, the solid-liquid ratio is preferably 800 g/L or less. Although sufficient effects can be obtained at room temperature (around 15 to 25° C.) for the acid leaching treatment (atmospheric temperature, acid solution temperature, etc.), heating may be performed. The heating temperature can be, for example, 60 to 80°C. If heating is performed, the reaction efficiency can be expected to improve as the temperature is raised within a range where the processing solution does not boil. The treatment time of the acid leaching treatment is preferably 5 minutes or more, and preferably 6 hours or less.

(Solid-liquid separation process)
In the solid-liquid separation step, the leachate obtained in the acid leaching step and the leaching residue are solid-liquid separated. The separated leachate contains manganese ions, zinc ions and iron ions. On the other hand, the separated solid leaching residue is primarily a result of residual carbon. Thereby, the manganese component, zinc component, and iron component contained in the powder and granules can be separated from carbon.

The solid-liquid separation means is not particularly limited. For the solid-liquid separation step, it is preferable to use commonly used means such as gravity sedimentation, filtration, centrifugation, filter press, membrane separation, and the like.

(Manganese extraction process)
In the present invention, it is necessary to perform a manganese extraction step in which zinc ions and iron ions are removed from the leachate separated in the solid-liquid separation step to obtain a solution containing manganese ions (manganese-containing solution) with high purity. . Specifically, the manganese extraction step includes a predetermined zinc removal step and 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 a sulfurizing agent is applied to zinc ions to precipitate them, and a zinc separation step in which the obtained 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 them, and an iron separation step of separating the obtained iron-containing precipitate.

In this way, in the manganese extraction process, zinc ions and iron ions are selectively precipitated, respectively, and by reliably removing zinc ions and iron ions from the leachate, the target component, manganese component, can be obtained with high purity. Moreover, it can be easily recovered with a high yield.

In the manganese extraction step, a zinc removal step in which zinc ions are preferentially precipitated and removed may be performed first (procedure A2), or an iron removal step in which iron ions are preferentially precipitated and removed may be performed first (procedure B). ). From the viewpoint of simplifying the process, it is preferable to perform the iron removal process first (procedure B).

In step A2, first, a mixture of a zinc-containing precipitate and a first solution containing manganese ions and iron ions is obtained from the leachate, and then these are separated. In step B, first, a mixture of an iron-containing precipitate and a third solution containing manganese ions and zinc ions is obtained from the leachate, and then these are separated. Details of procedure A2 and procedure B will be explained below.

(Zinc removal process (procedure A2))
In the zinc removal step in step (A2), the solid-liquid separated leachate is first subjected to a sulfide precipitation treatment step. In this sulfide precipitation treatment step, a sulfiding agent is applied to the leachate to precipitate mainly remaining zinc ions among the ions contained in the leachate as zinc sulfide, which can be removed from the leachate. By this treatment, a mixture of a first solution containing manganese ions and iron ions and a zinc-containing precipitate is obtained from the leachate.

The leachate separated in the solid-liquid separation process contains manganese ions, iron ions, and residual zinc ions. When a sulfurizing agent is applied to the leachate, the divalent metal ions contained in the leachate are converted into sulfide ions S. ^2- to produce and precipitate sulfide. The ease with which sulfides precipitate depends on the solubility product _KSP . The solubility products of manganese, zinc, and iron sulfides are shown below.
MnS:K _SP =2.5×10 ^-10
ZnS:K _SP =1.6×10 ^-24
FeS:K _SP =6.3×10 ^-18
(Lange, N.A.: Lange's Handbook of Chemistry. Thirteenth edition 1985)

The smaller the value of the solubility product _KSP , the easier it is to form sulfides, so that among manganese, zinc, and iron, zinc (Zn) is the most likely to form sulfides. Therefore, when a sulfurizing agent is applied to a leachate containing manganese, zinc, and iron ions, zinc (Zn) can be selectively precipitated as sulfide. By adjusting the concentration of sulfide ions and the pH of the leachate, the concentration of zinc ions in the leachate can be easily reduced to below the analysis limit (0.1 mg/L).

As mentioned above, if the leachate contains a large amount of zinc ions, a large amount of fine zinc-containing precipitate will be generated in the sulfide precipitation treatment process, which will promote co-precipitation of manganese and produce the final Easily reduces manganese yield. Further, during the subsequent solid-liquid separation, filter cloths etc. are likely to become clogged, making the zinc separation process difficult. However, in the present invention, in the acid/oxidizing agent treatment step prior to the sulfide precipitation treatment step, most of the zinc components in the powder and granules are removed in advance while retaining the manganese component, so coprecipitation of manganese is improved. can be avoided to increase the final manganese yield. Further, the quantity and quality of the zinc-containing precipitate can be controlled, and the zinc separation step described below can be performed simply and efficiently.

Suitable examples of the sulfurizing agent to be used include sodium hydrosulfide (NaHS), sodium sulfide (NaS), and hydrogen sulfide ( _H2S ). Here, since hydrogen sulfide is a gas, it is necessary to aerate it. Therefore, as the sulfurizing agent to be used, sodium hydrosulfide and sodium sulfide are more preferable.

The sulfurizing agent is added only when the pH change after addition of the sulfurizing agent is +1 or less, more preferably +0.5 or less. Here, the pH shift is defined as (pH shift) = (pH after addition of the sulfurizing agent) - (pH before adding the sulfurizing agent). By adding the sulfurizing agent only while the pH change is below +1, zinc ions can be precipitated better, while unintended precipitation of manganese ions can be more easily suppressed, and the amount of sulfurizing agent that is applied may be excessive, causing sulfurization. Generating a large amount of hydrogen gas can be prevented.

In addition, if the pH of the leachate when the sulfurizing agent is applied is too low (less than 2), precipitation of zinc tends to be insufficient, whereas if it is too high (higher than 6), the amount of manganese precipitated increases, reducing the amount of manganese that can be recovered. The reduction is significant, manganese loss progresses, and manganese yield tends to decrease. From this viewpoint, the pH of the leachate in the sulfide precipitation treatment step is preferably 2 or more, more preferably 3 or more, preferably 6 or less, more preferably 5 or less, and even more preferably less than 5. The pH of the leachate 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, even more preferably 3 or more and less than 5.

Subsequently, in the zinc removal step in step (A2), the mixture obtained in the above-described sulfide precipitation treatment step is separated into a first solution and a zinc-containing precipitate, and the zinc component is removed.

More specifically, the first solution containing manganese ions and iron ions obtained in the sulfide precipitation treatment step is separated from the zinc-containing precipitate in which residual zinc sulfide is precipitated. Thereby, the zinc component can be easily separated from the mixture after the sulfide precipitation treatment step, and the first solution containing manganese ions and iron ions can be obtained. The separation means is not particularly limited, and may follow the solid-liquid separation process described above. If the generated zinc-containing precipitate is large or fine, troubles such as coprecipitation of manganese and clogging of filter cloth during zinc separation are likely to occur. In the present invention, in the acid/oxidizing agent treatment process, most of the zinc components in the powder are removed in advance while retaining the manganese components, so coprecipitation of manganese is effectively avoided and the final step of manganese is It can increase retention. Moreover, the amount and fineness of zinc-containing precipitates can be suppressed, and the zinc separation process can be performed simply and efficiently.

Here, in the above-described sulfide precipitation treatment, part of the iron (Fe) component may be precipitated and removed from the solution. In this case, if the iron content has been removed to a level below a preset iron component concentration, it is possible to terminate the process at this stage. However, in step (A2), an iron removal step to be described later is further performed in order to further separate and remove the iron component to obtain a highly pure manganese component.

(Iron removal process (procedure A2))
In step (A2), following the zinc removal step described above, an iron removal step is performed. In the iron removal step in step (A2), first, the first 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 first solution are converted into iron-containing precipitates. As a material, it makes it possible to separate and remove iron components. Through this treatment, a mixture of a second solution (manganese-containing solution) containing highly purified manganese ions and an iron-containing precipitate is obtained from the first solution.

As for the oxidation treatment method, the oxidation treatment method in step (B) described below, including the appropriate pH of the first solution, may be followed. Here, if the first solution obtained through the sulfide precipitation treatment step is subjected to air aeration under practical conditions, the iron component in the first solution may not be completely separated and removed. This is because the sulfurizing agent added in the sulfide precipitation treatment process acts as a reducing agent in this process. This is considered to be because the 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 content that cannot be separated and removed remains in the solution after treatment. If air aeration is continued, the sulfiding agent becomes sulfate ions, and eventually the solution becomes an oxidizing atmosphere, and iron components 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 perform air aeration and then further add an oxidizing agent as a final oxidation treatment. The amount of the oxidizing agent added is preferably adjusted by measuring the redox potential (vs. SHE) so that the redox potential is 550 mV or more. Preferred examples of the oxidizing agent include hydrogen peroxide and potassium permanganate.

Here, if the zinc removal step is followed by an oxidation treatment step after being left for an appropriate period of time, the iron component can be sufficiently precipitated by air aeration alone, without performing a final oxidation treatment. This is because hydrogen sulfide, which is a reducing substance in the first solution generated in the previous sulfide precipitation treatment step, is dissipated into the air, making the first solution more likely to be oxidized, that is, the redox potential is more likely to increase. This is thought to be due to the fact that The appropriate period here cannot be definitively stated because it varies depending on the storage conditions, such as whether it is in a closed system or an open system, but it is estimated to be about a few days to a week.

Then, in the iron removal step in step (A2), the mixture obtained in the above-described oxidation treatment step is separated into a second solution and an iron-containing precipitate, and the iron component is removed. In this way, a highly pure manganese-containing solution (second solution) can be recovered.

The separation means is not particularly limited and may follow the solid-liquid separation process described above.

(Iron removal process (procedure B))
Next, in the iron removal step in step (B), the leachate obtained in the solid-liquid separation step is first subjected to an oxidation treatment. In this oxidation treatment, the leachate is oxidized to precipitate iron ions among the ions contained in the leachate as an iron-containing precipitate, thereby making it possible to remove iron components from the leachate. This treatment yields a mixture of a third solution containing manganese and zinc ions and an iron-containing precipitate from the leachate.

As the oxidation treatment method, a commonly used oxidation treatment method can be applied, but in this embodiment, only air aeration, which is an inexpensive oxidation treatment method, is sufficient. The air aeration conditions should be the usual practical conditions (injection amount: (0.1 times to 1 times the amount of leachate)/min, aeration time: 15 to 60 minutes). Preferable from an economical point of view. Here, a process of adding an oxidizing agent may be added as final oxidation.

Here, the oxidation treatment is preferably performed by adjusting the pH of the leachate using a pH adjuster. If the pH of the leachate is too low, less than 3, it is difficult for the iron component to precipitate. On the other hand, if the pH of the leachate is too high, exceeding 7, the manganese component also tends to precipitate at the same time. For this reason, it is preferable to adjust the pH of the leachate to a range of 3 to 7. The pH of the leachate is more preferably 5 or more, more preferably 6 or less, and even more preferably around pH 5 to pH 6. As a result, the iron component can be precipitated and separated and removed from the leachate while suppressing the precipitation of manganese, and as a result, a high-purity manganese-containing solution with few impurities can be obtained at a high yield.

Subsequently, in the iron removal step in step (B), the mixture obtained in the oxidation treatment step described above is treated 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.

The separation means is not particularly limited and may follow the solid-liquid separation process described above.

(Zinc removal process (procedure B))
In step (B), following the iron removal step described above, a zinc removal step is performed. In the zinc removal step in step (B), a sulfiding agent is applied to the third solution obtained in the previous iron removal step, and among the ions in the third solution, mainly zinc ions are precipitated as zinc sulfide and remain. Allowing the zinc component to be removed from the third solution. Through this treatment, a mixture of a fourth solution (manganese-containing solution) containing highly purified manganese ions and a 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 a sulfiding agent is applied to the third solution, the sulfide precipitation treatment step of step (A2) described above is carried out. Following a similar mechanism, zinc components selectively precipitate as sulfides. Then, by adjusting the amount of sulfiding agent added, the concentration of sulfide ions, and the pH of the third solution, the concentration of zinc ions in the third solution can be easily reduced to below the analytical limit (0.1 mg/L). be able to.

The type of sulfurizing agent and the suitable pH of the third solution may be determined according to the type of sulfurizing agent and the pH of the leachate suitable for the sulfide precipitation treatment in step (A2) described above. The pH of the third solution is particularly preferably pH:4.

The sulfurizing agent is added only when the pH change after addition of the sulfurizing agent is +1 or less, more preferably +0.5 or less. Here, the pH shift is defined as (pH shift) = (pH after addition of the sulfurizing agent) - (pH before adding the sulfurizing agent). By adding the sulfurizing agent only while the pH change is below +1, zinc ions can be precipitated better, while unintended precipitation of manganese ions can be more easily suppressed, and the amount of sulfurizing agent that is applied may be excessive, causing sulfurization. Generating a large amount of hydrogen gas can be prevented.

In the zinc removal step in step (B), the mixture obtained in the sulfide precipitation treatment step described above is separated into a fourth solution and a zinc-containing precipitate in which zinc sulfide is precipitated, and the zinc component is removed. 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 with a high yield.

As mentioned above, if the third solution contains a large amount of zinc ions, a large amount of fine zinc-containing precipitates will be generated in the sulfide precipitation treatment process, which will promote co-precipitation of manganese and produce the final manganese. It is easy to reduce the yield. Further, during the subsequent solid-liquid separation, filter cloths etc. are likely to become clogged, making the zinc separation process difficult. However, in the present invention, in the acid/oxidizing agent treatment step prior to the sulfide precipitation treatment step, most of the zinc components in the powder and granules are removed in advance while retaining the manganese component, so coprecipitation of manganese is improved. can be avoided to increase the final manganese yield. Moreover, the quantity and quality of the zinc-containing precipitate can be controlled, and the zinc separation process can be performed simply and efficiently.

The separation means is not particularly limited and may follow the solid-liquid separation process described above.

By going through each of the above steps in sequence, carbon components other than manganese components, zinc components, and iron components contained in waste dry batteries can be almost completely separated and removed. It can be recovered with a high yield as a pure manganese-containing solution.

Here, the obtained manganese-containing solution may be used for various purposes as a highly pure manganese hydroxide by, for example, alkali precipitation. Further, the obtained manganese-containing solution may be mixed with other metals such as Ni, subjected to an alkali precipitation treatment, etc., and used as a material for a secondary battery electrode material.

(Manganese recovery equipment)
Next, the manganese recovery equipment of the present invention will be explained. The recovery equipment of the present invention includes, in order, a sorting device, a crushing device, a sieving device, an acid treatment tank, a solid-liquid separation device, and a group of manganese extraction devices, and has the same characteristics and effects as the manganese recovery method of the present invention. Further, the manganese extraction device group includes a predetermined zinc removal device group and iron removal device group in random order.

The manganese recovery equipment of the present invention can be suitably used, for example, when implementing the manganese recovery method of the present invention.

(Configuration A2)
As one aspect of the recovery equipment of the present invention, FIG. 8 shows a configuration (A2) that can suitably implement the above-described procedure (A2). 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 solid-liquid separation device 40, and a sulfide precipitation treatment tank 50. , a pH meter 60, a zinc separation device 70, an oxidation treatment tank 80, an iron separation device 90, and a manganese-containing solution recovery tank 140, which can be provided in this order from upstream to downstream. Here, the sulfide precipitation treatment tank 50, the pH meter 60, and the zinc separation device 70 constitute a zinc removal device group, and the oxidation treatment tank 80 and the iron separation device 90 constitute an iron removal device group. Further, the zinc removal device group and the iron removal device group constitute a manganese extraction device group.

The sorting device 10 sorts 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 suitable examples include devices that sort using shape, radiation, or the like. Here, the waste dry batteries may be sorted manually.

Although any ordinary crusher can be used as the crusher 20a, it is preferable to use a two-axis rotating type crusher.

The sieving device 20b is preferably equipped with a sieve with an opening of 1 mm or more and 20 mm or less. The opening of the sieving device 20b is preferably 1 mm or more, preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 3 mm or less, for the same reason as described above regarding the manganese recovery method.

The acid treatment tank 30 is a general stirring tank equipped with a stirrer in order to mix the powder, the acid solution, and the oxidizing agent, as well as the leaching residue, the acid solution, and the reducing agent to advance the leaching reaction. It is preferable to use a tank. When using a reducing agent, it is preferable to further include equipment for adding the reducing agent into the tank.

The sulfide precipitation treatment tank 50 is preferably a general stirring tank equipped with a stirrer in order to perform a sulfurizing agent treatment in which a sulfurizing agent is applied to the leachate. Additionally, a pH meter 60 is provided for controlling the amount of sulfurizing agent added while monitoring the pH change. Furthermore, it is preferable to further include a pH adjusting device capable of adjusting the pH of the leachate by adding a pH adjusting agent.

Further, the oxidation treatment tank 80 is preferably a general stirring tank equipped with a stirrer in order to perform the oxidation treatment on the first solution. Moreover, it is preferable to further include a pH adjusting device capable of adjusting the pH of the first solution by adding a pH adjusting agent.

For each of the solid-liquid separator 40, the zinc separator 70, and the iron separator 90, a device selected from a gravity sedimentation separator, a filtration device, a centrifugal separator, a filter press device, a membrane separator, etc. can be used. . Here, it is preferable that each separation device includes recovery tanks 110, 120, and 130 that can recover the solid-liquid separated precipitate and the like.

It is preferable that the manganese-containing solution recovery tank 140 is a tank that can collect and store the manganese-containing solution separated into solid and liquid by the iron separator 90 and can be freely discharged.

(Configuration B)
Moreover, as another aspect of the recovery equipment of the present invention, FIG. 9 shows a configuration (B) that can suitably implement the above-mentioned procedure (B). As schematically shown in FIG. 9, the recovery equipment includes a sorting device 10, a crushing device 20a, a sieving device 20b, an acid treatment tank 30, a solid-liquid separation device 40, an oxidation treatment tank 51, and a The separation device 61, the sulfide precipitation treatment tank 71, the pH meter 81, the zinc separation device 91, and the manganese-containing solution recovery tank 140 can be provided in this order from upstream to downstream. Here, the oxidation treatment tank 51 and the iron separation device 61 constitute an iron removal device group, and the sulfide precipitation treatment tank 71, the pH meter 81, and the zinc separation device 91 constitute a zinc removal device group. Further, the iron removal device group and the zinc removal device group constitute a manganese extraction device group.

Here, a sorting device 10, a crushing device 20a, a sieving device 20b, an acid treatment tank 30, a solid-liquid separation device 40, an iron separation device 61, a zinc separation device 91, recovery tanks 110, 121, 131, a manganese-containing solution recovery tank 140 are all as described above for configuration A2. Here, the iron separator 61, the zinc separator 91, and the recovery tanks 121 and 131 correspond to the iron separator 90, the zinc separator 70, and the recovery tanks 130 and 120 of configuration A2, respectively.

The oxidation treatment tank 51 is preferably a general stirring tank equipped with a stirrer in order to perform oxidation treatment on the leachate. Moreover, it is preferable to further include a pH adjusting device capable of adjusting the pH of the exudate by adding a pH adjusting agent.

Further, the sulfide precipitation treatment tank 71 is preferably a general stirring tank equipped with a stirrer in order to perform the sulfide precipitation treatment in which a sulfurizing agent is applied to the third solution. Additionally, a pH meter 81 is provided for controlling the amount of sulfurizing agent added while monitoring the pH change. Furthermore, it is preferable to further include a pH adjusting device capable of adjusting the pH of the third solution by adding a pH adjusting agent.

Here, in this embodiment, the structures of the various devices, reaction vessels, and recovery vessels constituting the recovery facility are not limited as long as they have the respective functions described above.

Examples will be described below. Here, the following example shows a preferred example of the present invention, and is not intended to limit the invention in any way. Further, the following embodiments may be modified and implemented within the scope of the spirit of the present invention, and such embodiments are also included within the technical scope of the present invention.

(Example 1)
(Preparation of granular material)
A granular material of waste dry batteries was obtained through a sorting step of sorting out manganese dry batteries and alkaline manganese dry batteries from waste dry batteries, and by crushing the sorted waste dry batteries and sieving through a sieve with an opening of 2.8 mm. Table 1 shows the composition of the obtained powder. Here, the obtained powder contains, in addition to the elements shown in Table 1, oxygen derived from the oxide or hydroxide and some hydrogen.

(Preparation of leachate)
50 g of the obtained granular material was mixed with 500 mL of an acid solution and 22.5 g of hydrogen peroxide H ₂ O ₂ as a reducing agent, and an acid leaching treatment was performed to leach manganese, zinc, and iron from the granular material. It was done. The acid concentration of the acid solution was sulfuric acid concentration: 2N (mass% concentration: about 9.0%). Here, the acid leaching treatment time was 1 hour, and the acid leaching treatment was a stirring treatment. In this case, the solid-liquid ratio, which is the ratio between the powder and the acid solution, is 100 g/L, and the amount of reducing agent added to the acid solution is 45 g/L.

(Solid-liquid separation process)
After the acid treatment step, the mixture of the obtained leachate and leach residue was filtered through a filter paper with a pore size of 1 μm to perform solid-liquid separation. The manganese concentration, zinc concentration, and iron concentration (mg/L) in the obtained leachate were determined by ICP emission spectrometry. Table 2 shows the quantitative results. Here, the manganese leaching rate is determined by determining the mass of manganese in the leachate based on the obtained analysis value and calculating the ratio of the mass in the leachate to the mass in the powder (in terms of each element). It was found to be approximately 95%.

(Preparation of first solution (zinc removal process))
Next, the leachate obtained from the solid-liquid separation step was added to sodium bisulfide, NaHS, as a sulfiding agent. The sulfurizing agent was added so that the pH change after adding the sulfurizing agent was within +1. Further, the pH of the leachate during the sulfide precipitation treatment was adjusted to 4 using a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide). Further, the treatment time for the sulfide precipitation treatment was 30 minutes, and the treatment was performed with stirring.

The mixture after the above-described sulfide precipitation treatment step was suction filtered through a filter paper with a pore size of 1 μm to separate the first solution and the zinc-containing precipitate (zinc separation step). Then, the components of the obtained first solution were quantitatively analyzed by ICP emission spectrometry. Here, the amounts of sodium bisulfide solution and pH adjuster added were recorded and the effects of dilution with these solutions were corrected from the analytical values. In Table 2, the obtained results are also listed as "first solution after zinc removal step".

(Preparation of second solution (iron removal process))
The first solution obtained through the zinc removal step was then subjected to air aeration as an oxidation treatment. The conditions for air aeration were that the blowing amount was (same volume as the first solution amount)/min and the aeration time was 30 minutes. After air aeration, the intermediate solution was suction-filtered through a filter paper with a pore size of 1 μm, and the components contained therein were quantitatively analyzed using the above method. In Table 2, the obtained results are also listed as "intermediate solution after oxidation treatment".

Then, as a further oxidation treatment, an oxidizing agent was immediately added to the first solution after the air aeration. In the addition of the oxidizing agent, the pH of the first solution was adjusted to 5 by adding a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide), and then adding hydrogen peroxide as the oxidizing agent. It was added so that the reduction potential was 550 mV or more. In this way, the iron component in the first solution was precipitated as iron hydroxide, and became ready for removal. Here, the treatment time with the oxidizing agent was 30 minutes.

After the oxidation treatment step by air aeration and addition of an oxidizing agent, the mixture was suction-filtered through a filter paper with a pore size of 1 μm, and an iron separation step was performed in which solid-liquid separation was performed into a manganese-containing solution (second solution) and an iron-containing precipitate. .

The components contained in the obtained second solution were quantitatively analyzed using the above method. Here, the amounts of hydrogen peroxide solution and pH adjuster added were recorded, and the analytical values were corrected for the effects of dilution with these solutions. In Table 2, the obtained results are also listed as "second solution after iron removal step".

From Table 2, according to procedure A2, which is an embodiment of the manganese recovery method of the present invention, zinc components and iron components other than manganese components contained in waste dry batteries can be reduced to below the analysis limit (0.1 mg/L). It can be seen that it can be easily separated and removed. As described above, it can be seen that according to the present invention, the manganese component contained in waste dry batteries can be easily and efficiently recovered as a high-purity manganese ion-containing solution with a high yield.

(Example 2)
A granular material was prepared in the same manner as in Example 1, and a granular material having the composition shown in Table 1 was obtained. Furthermore, when a leachate was prepared in the same manner as in Example 1, the contents (mg/L) of each component of manganese, zinc, and iron in the leachate after the solid-liquid separation step were as shown in Table 3. Here, the manganese leaching rate determined in the same manner as in Example 1 was about 95%.

Next, a first solution was prepared (zinc removal step) in the same manner as in Example 1, and the components in the first solution after the zinc removal step were as shown in Table 3.

Next, the first solution obtained through the zinc separation step was left to stand at room temperature for one week, and then an oxidation treatment step was performed. In the oxidation treatment process, only air aeration was performed. The air aeration conditions were as follows: blowing amount: (same volume as the third solution amount)/min, and aeration time: 30 minutes. After air aeration, the manganese-containing solution (second solution) was suction-filtered through a filter paper with a pore size of 1 μm, and the components contained therein were quantitatively analyzed using the above method. In Table 3, the obtained results are also listed as "second solution after iron removal step".

From Table 3, it can be seen that if the first solution separated by the sulfide precipitation treatment is subjected to the oxidation treatment step after being allowed to stand for an appropriate period of time in step A2, the iron content will be sufficient even with the oxidation treatment by air aeration alone. It can be seen that this can be separated and removed as a precipitate. As a result, we were able to recover manganese components at a high yield.

(Example 3)
A granular material was prepared in the same manner as in Example 1, and a granular material having the composition shown in Table 1 was obtained. Further, when an acid treatment step was performed in the same manner as in Example 1, the contents (mg/L) of each component of manganese, zinc, and iron in the leachate after the solid-liquid separation step were as shown in Table 4.

(Preparation of third solution (iron removal process))
Next, the leachate separated in the solid-liquid separation process was subjected to an oxidation treatment process. In the oxidation treatment step, the obtained leachate was aerated with air to generate iron hydroxide from the iron component contained in the leachate, and the iron component was made into a state where it could be separated and removed from the leachate as an iron-containing precipitate. The air aeration conditions were as follows: blowing amount: (same volume as leachate amount) mL/min, aeration time: 30 minutes. Here, in performing the oxidation treatment, the leachate was adjusted to pH: 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. Here, the amount of pH adjuster added was recorded, and the influence of dilution by the pH adjuster on the measured values was corrected. In Table 4, the concentrations (mg/L) of each component of manganese, zinc, and iron in the obtained first solution are also listed as "third solution after iron removal step".

(Preparation of fourth solution (zinc removal process))
Next, a sulfiding agent was applied to the third solution separated in the iron separation process, and the zinc ions remaining in the third solution were mainly precipitated as zinc sulfide (zinc-containing precipitate). . Then, a sulfide precipitation treatment step was performed to make it possible to separate and remove it from the third solution. The sulfurizing agent used was sodium hydrosulfide, NaHS, and was added so that the pH change after addition of the sulfurizing agent was within +1. Here, 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 using a pH adjusting solution (3M sulfuric acid or 100 g/L sodium hydroxide). Further, the treatment time for the sulfide precipitation treatment was 30 minutes, and the treatment was performed with stirring.

The mixture after the sulfide precipitation treatment was suction filtered through a filter paper with a pore size of 1 μm, and a treatment was performed to separate it into a manganese-containing solution (second solution) and a zinc-containing precipitate (zinc separation step). Then, the components of the fourth solution obtained after separation were quantitatively analyzed by ICP emission spectrometry. Here, the amounts of sodium bisulfide solution and pH adjuster added were recorded, and the measured values were corrected for the effects of dilution with these solutions. In Table 4, the obtained results are also listed as "4th solution after zinc removal step". The yield of Mn in the obtained fourth solution (solution containing manganese ions) was 95%.

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

10 sorting device 20a crushing device 20b sieving device 30 acid treatment tank 40 solid-liquid separation device 50 sulfide precipitation treatment tank 51 oxidation treatment tank 60 pH meter 61 iron separation device 70 zinc separation device 71 sulfide precipitation treatment tank 80 oxidation treatment tank 81 pH meter 90 Iron separation device 91 Zinc separation device 110 Recovery tank 120 Recovery tank 121 Recovery tank 130 Recovery tank 131 Recovery tank 140 Manganese-containing solution recovery tank

Claims (12)

a sorting step of sorting one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing and sieving step for obtaining powder and granular material by crushing and sieving one or both of the manganese dry batteries and alkaline manganese dry batteries sorted in the sorting step;
Acid leaching to obtain a leachate containing manganese ions, zinc ions, and iron ions contained in the powder by mixing an acid solution and a reducing agent with the powder obtained in the crushing and sieving step. process and
a solid-liquid separation step of separating the leachate obtained in the acid leaching step from other leaching residue;
a manganese extraction step of removing the zinc ions and iron ions from the leachate separated in the solid-liquid separation step to obtain a solution containing the manganese ions;
in this order,
The manganese extraction step is
a zinc removal step including a sulfide precipitation treatment step of causing a sulfiding agent to act on the zinc ions to precipitate the zinc ions; and a zinc separation step of separating the obtained zinc-containing precipitate;
an iron removal step including an oxidation treatment step of oxidizing the iron ions to precipitate the iron ions, and an iron separation step of separating the obtained iron-containing precipitate;
In no particular order,
A method for recovering manganese contained in waste dry batteries, in which a sulfurizing agent is applied only while the pH change after addition of the sulfurizing agent is +1 or less in the zinc separation step. The manganese extraction step is performed in the order of the zinc removal step and the iron removal step,
In the zinc removal step, after performing a sulfide precipitation treatment in which a sulfiding agent is applied to the leachate to precipitate zinc ions in the leachate, the zinc-containing precipitate and manganese ions obtained in the sulfide precipitation treatment step are removed. and a first solution containing iron ions are subjected to solid-liquid separation,
In the iron removal step, the first solution obtained in the zinc removal step is subjected to an oxidation treatment to precipitate iron ions in the first solution, and then the iron-containing solution obtained in the oxidation treatment step is 2. The method for recovering manganese contained in waste dry batteries according to claim 1, characterized by performing solid-liquid separation between the manganese and the second solution containing manganese ions. The method for recovering manganese contained in waste dry batteries according to claim 2, wherein in the sulfide precipitation treatment step, the pH of the leachate is adjusted to be 2 or more and 6 or less. In the oxidation treatment step, the first solution containing manganese ions and iron ions is aerated with air, or an oxidizing agent is further added to the first solution, and the first solution has a pH of 3 or more. The method for recovering manganese contained in waste dry batteries according to claim 2 or 3, wherein the manganese content is adjusted to be 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, after performing an oxidation treatment step of oxidizing the leachate to precipitate iron ions in the leachate, the obtained iron-containing precipitate and a third solution containing manganese ions and zinc ions are combined. An iron separation process is applied to solid-liquid separation,
In the zinc removal step, a sulfide precipitation treatment step is performed in which the third solution obtained in the iron removal step is treated with a sulfurizing agent to precipitate zinc ions in the third solution, and then the obtained zinc 2. The method for recovering manganese contained in waste dry batteries according to claim 1, which comprises performing a zinc separation step of solid-liquid separation of the contained precipitate and the fourth solution containing manganese ions. The method for recovering manganese contained in waste dry batteries according to claim 5, wherein in the sulfide precipitation treatment step, the third solution containing manganese ions and zinc ions is adjusted to have a pH of 2 or more and 6 or less. . The manganese contained in the waste dry battery according to claim 5 or 6, wherein in the sulfide precipitation treatment step, the leachate is aerated with air and the pH of the leachate is adjusted to be 3 or more and 7 or less. collection method. Claims 1 to 3, wherein the acid solution in the acid leaching step is dilute sulfuric acid with a mass % concentration of 1.4% to 45% or dilute hydrochloric acid with a mass % concentration of 1% to 14%. A method for recovering manganese contained in a waste dry battery according to any one of the items. Contained in the waste dry battery according to any one of claims 1 to 3, wherein the solid-liquid ratio between the powder and granular material in the acid leaching step and the acid leaching step is 50 g / L or more. How to recover manganese. According to any one of claims 1 to 3, the reducing agent in the acid leaching step is any one of hydrogen peroxide, sodium sulfide, sodium bisulfite, sodium thiosulfate, and iron sulfate. A method for recovering manganese contained in waste dry batteries. The waste according to any one of claims 1 to 3, wherein the sulfurizing agent used in the sulfide precipitation treatment step is any one of sodium bisulfide, sodium sulfide, and hydrogen sulfide. A method for recovering manganese contained in dry batteries. A sorting device that sorts one or both of manganese dry batteries and alkaline manganese dry batteries from waste dry batteries;
A crushing device in which one or both of the manganese dry batteries and alkaline manganese dry batteries sorted by the sorting device is charged and subjected to crushing treatment to obtain a crushed product;
a sieving device that performs a sieving process on the crushed material obtained by the crushing device to obtain a granular material;
The powder obtained by the sieving device is mixed with an acid solution and a reducing agent to leach out the manganese, zinc and iron contained in the powder, resulting in manganese ions, zinc an acid treatment tank for obtaining a leachate containing ions and iron ions;
a solid-liquid separator that separates the leachate and leach residue obtained in the acid treatment tank;
A manganese extraction device group that removes the zinc ions and iron ions from the leachate separated by the solid-liquid separator to obtain a solution containing the manganese ions;
in this order,
The manganese extraction device group is
A sulfide precipitation treatment tank that causes a sulfurization agent to act on the zinc ions to precipitate the zinc ions, a sulfide addition device that controls the amount of sulfurization agent treated according to a pH change in the sulfide precipitation treatment tank, and the obtained A zinc removal equipment group including a zinc separation equipment for solid-liquid separation of zinc-containing precipitates;
An iron removal device group including an oxidation treatment tank that oxidizes the iron ions and precipitates the iron ions, and an iron separation device that separates the obtained iron-containing precipitate into solid and liquid;
Equipment for recovering manganese contained in waste dry batteries, including in no particular order.

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