JP5568977B2 - Method for recovering manganese from batteries - Google Patents

Description

  The present invention relates to a method for recovering a manganese compound that can be used for producing electrolytic manganese dioxide from a battery.

  From the viewpoint of environmental problems and effective utilization of resources, it is required to collect and reuse used batteries, in particular, primary batteries containing manganese and zinc such as manganese dry batteries and alkaline manganese dry batteries. In particular, there is a strong demand to collect manganese material in dry batteries and reuse it as a raw material for electrolytic manganese dioxide for batteries.

  In order to use manganese in waste dry batteries as a raw material for electrolytic manganese dioxide for batteries, manganese can be used as zinc compounds, carbon rods, electrolytes such as zinc chloride and potassium hydroxide, separators, and can metals (iron, nickel). , Copper) and the like, and it is necessary to recover by reducing the potassium concentration to a level equal to or lower than that of manganese ore.

  Conventionally, the recycling of waste batteries has been performed by extracting valuable metals that dissolve the residue from which iron has been removed by magnetic separation after the waste batteries are heated and calcined. However, in this method, manganese reacts with potassium and iron by heating smoldering to produce a hardly decomposable compound, and manganese and potassium cannot be separated and recovered from this hardly decomposable compound ( Patent Documents 1 and 2).

  In addition, as a method not forming such a hard-to-decompose compound, a recovery method in which it is dissolved in sulfuric acid or hydrochloric acid without carrying out a heat smoldering treatment has been studied. However, these recovery methods have problems such as requiring different treatment steps between the manganese battery and the alkaline manganese battery (Patent Documents 3 and 4). Further, in any of these methods, potassium removal is not sufficient, and recovery is performed. The product could not be used as a raw material for electrolytic manganese dioxide (Patent Documents 5 to 7).

  In addition, a method of recovering manganese dioxide and carbon by treating the contents of a waste dry battery with an acid solution such as hydrochloric acid or sulfuric acid and dissolving and separating impurities such as zinc and potassium has been proposed (Patent Document 8). However, this method cannot recover soluble manganese, and increasing the manganese recovery rate decreases the removal rate of potassium and zinc in the recovered material.

  Thus, in the conventional method for recovering manganese from dry batteries, a low potassium concentration manganese compound that can be used as a raw material for electrolytic manganese dioxide cannot be recovered at a high recovery rate.

Japanese Patent Laid-Open No. 02-187187 Japanese Patent Publication No. 03-006208 Japanese Patent Publication No. 03-031116 Japanese Patent Laid-Open No. 11-191439 JP 61-281467 A JP 04-310280 A JP 2001-256984 A JP2007-012527

  The present invention provides a method capable of recovering a manganese compound that can be used as a raw material for electrolytic manganese dioxide from a battery electrode member-containing material at a high recovery rate.

  As a result of earnest studies on a method of recovering from a dry battery as a manganese compound that can be used as a raw material for electrolytic manganese dioxide, the inventor has specifically dissolved an electrode member content of a battery such as a manganese battery or an alkaline manganese battery. -The process which controls the reprecipitation conditions and can obtain the manganese compound which can be used as a raw material for electrolytic manganese dioxide at a high recovery rate has been found, and the present invention has been completed.

  That is, the present invention is a first step in which a battery electrode member-containing material is treated at 2 ≦ pH ≦ 4 and separated into a solid phase (solid phase 1) and a liquid phase (liquid phase 1), and the obtained liquid phase ( The second step of treating liquid phase 1) with 7 ≦ pH ≦ 9 and further separating it into a solid phase (solid phase 2) and a liquid phase (liquid phase 2), and the resulting liquid phase (liquid phase 2) to pH This is a method for recovering manganese from a battery in which solid phase 1 and / or solid phase 3 is recovered by a third step of treatment at ≧ 10.

  Hereinafter, the recovery method of the present invention will be described in detail.

  The method of the present invention includes a first step of treating a battery electrode member-containing material at 2 ≦ pH ≦ 4 to separate it into a solid phase (solid phase 1) and a liquid phase (liquid phase 1).

  In the present invention, the battery is mainly a primary battery after discharge, a manganese dry battery, an alkaline manganese dry battery, and a mixture thereof, manganese oxide such as manganese dioxide as a positive electrode mixture, and zinc oxidation such as metallic zinc as a negative electrode. And the electrolytic solution contains a solution mainly composed of an aqueous zinc chloride solution or an aqueous potassium hydroxide solution. Further, these batteries used for manganese recovery (used batteries) do not have to be completely discharged, and may be in different discharge states. Further, the used battery may include a battery that is not discharged or is in a discharged state.

  The battery has members other than the positive electrode, the negative electrode, the electrolytic solution, and a mixed compound thereof, but the battery electrode member-containing material used for the recovery of manganese by the method of the present invention includes a battery jacket, iron / nickel, etc. that are not electrode members It is preferable to remove the outer cans, external terminals, outer parts such as plastics, current collectors, plastics such as separators, and outer members such as papers.

  The electrode member-containing material after the exterior member is removed from the battery is mainly composed of a positive electrode, a negative electrode, an electrolytic solution and a mixture thereof, and is mainly a secondary compound contained in a manganese compound, a zinc compound, a potassium compound, and a positive electrode mixture. It is a mixture containing components (carbon components such as carbon and acetylene black which are conductive materials (hereinafter simply referred to as “carbon components”) and positive electrode additives).

  Since the electrode member-containing materials to be treated by the method of the present invention are obtained from used batteries having different discharge degrees, the compounds contained in the electrode member-containing materials include those in various states. Therefore, the manganese compound and the zinc compound in the electrode member-containing material to be treated by the method of the present invention may be in various reduced / oxidized states, or may be in a mixed compound state. In particular, manganese compounds may be present in a state containing different amounts of zinc ions and potassium ions. Therefore, it is sufficient that the electrode member-containing material is obtained from a used battery, and it is not necessary to further classify the type of battery, such as separation between a manganese battery and an alkaline manganese battery, separation by battery shape, and separation by discharge degree.

  Examples of the method for obtaining the electrode member-containing material in the present invention include a method in which a used battery is pulverized, and the obtained pulverized material is subjected to magnetic separation and wind separation to remove an exterior member. On the other hand, when it is processed by a heating process such as firing or sinter, manganese forms a hardly soluble compound with potassium. Therefore, it is preferable not to perform heat treatment when obtaining the electrode member-containing material.

  The treatment pH in the first step of the present invention is 2 ≦ pH ≦ 4, and preferably 2.5 ≦ pH ≦ 3.5. By setting the treatment pH within this range, components such as potassium and zinc can be separated into the liquid phase (liquid phase 1). When the pH is less than 2 or more than 4, insoluble alum containing potassium and zinc is incorporated into the solid phase (solid phase 1), and the potassium content in the manganese compound in the solid phase (solid phase 1) increases. To do.

  The treatment of the electrode member-containing material at 2 ≦ pH ≦ 4 is not particularly limited as long as it is performed using an aqueous acid solution, but an aqueous sulfuric acid solution is preferably used for the acid solution. Since electrolytic manganese dioxide is produced from a sulfuric acid-manganese sulfate bath, even if the recovered manganese contains sulfate radicals, there is no adverse effect when used as a raw material for electrolytic manganese dioxide. On the other hand, when an acid aqueous solution other than sulfuric acid, for example, a hydrochloric acid aqueous solution is used, a problem of chlorine gas occurs, or the zinc compound is eluted in the second step to be described later due to the mixing of chlorine ions, and the manganese compound is recovered. The zinc concentration tends to be high.

  The acid concentration in the acid aqueous solution is not particularly limited, but if the concentration is too high, a load is easily applied to the processing apparatus such as heat generation during the processing. Therefore, 15 mol% or less can be illustrated as acid concentration of the final acid aqueous solution in the 1st process mentioned later.

  In the first step, after the electrode member-containing material is treated at 2 ≦ pH ≦ 4, the solid phase (solid phase 1) and the liquid phase (liquid phase 1) are separated, and the solid phase (solid phase 1) is recovered. Thereby, an insoluble manganese compound and a carbon component can be separated and recovered as a solid phase (solid phase 1) and potassium and zinc as a liquid phase (liquid phase 1).

  When the electrode member-containing material is treated in the first step of the present invention, it is preferable to add water to the residue mixture to make a slurry before adding the aqueous acid solution. When an acid aqueous solution is directly added to the electrode member-containing material, a rapid and local pH drop occurs, and thus manganese in the electrode member-containing material easily forms a hardly decomposable compound with potassium. Water added to the electrode member-containing material is not particularly limited as long as it does not substantially contain metal impurities. Although the density | concentration of an electrode member containing material slurry will not be restrict | limited especially if an electrode member containing material disperse | distributes, 550 g / L or less can be illustrated as an electrode member containing material slurry density | concentration after adding water.

  In the first step of the present invention, the pH is preferably adjusted by adjusting the amount of the acid aqueous solution and the acid concentration. By adjusting the pH with an acid aqueous solution, it is possible to prevent contamination from impurities derived from the pH adjuster.

  Although there is no restriction | limiting in the processing amount of the electrode member containing material in the 1st process of this invention, 100-500 g / L can be illustrated as an electrode member containing material density | concentration in the slurry after pH adjustment. When the concentration of the electrode member-containing material is less than 100 g / L, the recovery efficiency tends to be remarkably lowered, and when it exceeds 500 g / L, the treatment time tends to be long.

  The treatment temperature in the first step of the present invention is not particularly limited as long as the zinc compound and potassium in the electrode member-containing material are eluted, but for example, 20 to 60 ° C is preferable, and 40 to 60 ° C is particularly preferable. Moreover, 0.5 to 5 hours can be mentioned as processing time.

  The separation and recovery method of the solid phase in the first step of the present invention is not limited as long as the treatment pH can be separated into a solid phase and a liquid phase after sufficient treatment at 2 ≦ pH ≦ 4. It can be exemplified that the solid phase 1) and the filtrate (liquid phase 1) are separated and recovered.

  Since the liquid phase 1 obtained in the first step contains a soluble manganese compound, zinc, and potassium, manganese can be further separated and recovered by the following treatment.

  In the present invention, zinc and the like in the liquid phase 1 and manganese are further separated by a second step in which the liquid phase (liquid phase 1) obtained in the first step is further treated at 7 ≦ pH ≦ 9.

  The treatment pH in the second step of the present invention is 7 ≦ pH ≦ 9, preferably 8 ≦ pH ≦ 9. By setting the treatment pH within this range, manganese and potassium can be separated into the liquid phase 2 and zinc can be separated into the solid phase 2 as an insoluble compound.

  The method for adjusting the pH in the second step of the present invention is to adjust the pH using a solution containing no alkaline earth metal such as calcium and potassium, such as aqueous ammonia, aqueous sodium hydroxide, aqueous sodium carbonate, etc. It is preferable. In particular, it is preferable to adjust the pH using aqueous ammonia because there is no contamination of metal cations. When a solution containing an alkaline earth metal is used for pH adjustment, such as a calcium hydroxide aqueous solution, a calcium carbonate aqueous solution or a potassium hydroxide aqueous solution, the alkaline earth metal or potassium is likely to be mixed into the liquid phase, and separation from manganese is possible. It tends to be difficult.

  The treatment temperature in the second step of the present invention is not particularly limited as long as the precipitation of zinc into the solid phase proceeds, and for example, 20 to 60 ° C is preferable, and 40 to 60 ° C is particularly preferable. Moreover, 0.5 to 5 hours can be mentioned as processing time.

  The method for separating and recovering the liquid phase in the second step of the present invention is not limited as long as it can be separated into a solid phase (solid phase 2) and a liquid phase (liquid phase 2) after sufficiently treating the treatment pH at 7 ≦ pH ≦ 9. Without separation, the filtrate can be separated and recovered as the liquid phase 2 by a normal filtration method.

  In the third step of the present invention, the liquid phase 2 obtained in the second step is treated at pH ≧ 10, and then the solid phase (solid phase 3) is recovered. Thereby, manganese contained in the liquid phase 2 obtained in the second step can be separated and recovered from potassium.

  In the present invention, the liquid phase 2 obtained in the second step is treated at pH ≧ 10 to perform the third step to obtain the solid phase 3 having manganese. When the treatment pH in the third step is pH <10, manganese tends to remain in the liquid phase (liquid phase 3), and the recovery rate of manganese to the solid phase (solid phase 3) decreases.

  The method of adjusting the pH in the third step of the present invention is preferably adjusted with an aqueous solution containing no alkaline earth metal such as calcium or potassium, such as aqueous ammonia, sodium hydroxide, sodium carbonate, etc. It is preferable to adjust the pH with aqueous ammonia containing no cation. When a solution containing an alkaline earth metal or potassium, for example, an aqueous calcium hydroxide solution, an aqueous calcium carbonate solution, or an aqueous potassium hydroxide solution is used for pH adjustment, these are likely to be mixed into the solid phase 3.

  The treatment temperature in the third step of the present invention is not particularly limited as long as the precipitation of manganese into the solid phase proceeds. For example, 20 to 60 ° C is preferable, and 40 to 60 ° C is particularly preferable. Moreover, 0.5 to 5 hours can be mentioned as processing time.

  In the third step of the present invention, it is preferable to perform the treatment by adding an oxidizing agent. By adding an oxidizing agent, precipitation of manganese on the solid phase 3 is promoted, and the recovery rate of manganese can be increased. The oxidizing agent to be used is not particularly limited as long as it does not contain any metal element other than manganese. However, since the oxidizing agent itself can be recovered in the solid phase, manganese oxide is particularly preferable, and further manganese dioxide. Is preferred. In addition, when an oxidizing agent is added in the first step and the second step, zinc is easily taken into manganese. Therefore, it is preferable not to add an oxidizing agent except in the third step.

  In the third step of the present invention, the liquid phase (liquid phase 3) and the solid phase (solid phase 3) are separated into the solid phase 3 and the liquid phase 3 after sufficiently treating with a treatment pH of pH ≧ 10. There is no limitation as long as phase 3 can be recovered, and the filtration residue can be separated and recovered as solid phase 3 by a normal filtration method.

  In the method of the present invention, the solid phase 1 and / or the solid phase 3 obtained in the first step and the third step are recovered. The recovered solid phase 1 and / or solid phase 3 can be appropriately dried and reused as a raw material for electrolytic manganese dioxide.

  In the method of the present invention, the manganese recovery rate is high, and the removal rate of zinc and potassium is high. Therefore, 90% or more, preferably 95% or more of manganese contained in the electrode member-containing material can be recovered. Moreover, 90% or more, preferably 95% or more of zinc and potassium contained in the electrode member-containing material can be removed.

  In the method of the present invention, carbon can be recovered in addition to manganese. The carbon recovery rate is preferably 90% or more, particularly 95% or more of the carbon content of the electrode member-containing material. The recovered carbon content is contained in a manganese compound, and can be used as a reducing agent when the same treatment as manganese ore is performed as a raw material for electrolytic manganese dioxide.

  The manganese compound recovered by the method of the present invention has a potassium concentration of 1% by weight or less, preferably 0.8% by weight or less, based on the metal element in the manganese compound. When the potassium concentration in the manganese compound exceeds 1% by weight, it is used simultaneously with manganese ore (potassium concentration with respect to all metal elements in the ore: 1.2% by weight to 2.0% by weight) to produce electrolytic manganese dioxide. It becomes difficult.

  The manganese compound recovered by the method of the present invention preferably has a total content of potassium and zinc of 5% by weight or less, preferably 4% by weight or less, based on the total amount of metal elements in the manganese compound. Particularly preferred. If the total content of potassium and zinc is 5% by weight or less, it can be used as an electrolytic manganese dioxide raw material together with manganese ore without further impurity treatment operations such as zinc removal with hydrogen sulfide.

  Even if a heavy metal element other than manganese is contained, the manganese compound recovered by the method of the present invention can be removed during the treatment of manganese ore in the usual electrolytic manganese dioxide production process. Therefore, there is no problem even if the recovered manganese compound contains heavy metal elements such as iron, nickel and titanium, but the content is preferably 1% by weight or less.

  The manganese compound recovered by the method of the present invention has a low impurity content, particularly a potassium content, and the contained potassium does not produce manganese and a hardly decomposable compound. Therefore, the manganese compound recovered by the method of the present invention can be treated in the same manner as manganese ore as a raw material for electrolytic manganese dioxide, and can be applied as it is to conventional electrolytic manganese dioxide production processes. Further, the recovered manganese compound can be mixed with manganese ore as a raw material for electrolytic manganese dioxide, in addition to being used alone.

  By the method of the present invention, a manganese compound having a potassium concentration of 1% by weight or less can be recovered from a used battery at a high recovery rate.

Schematic of the manganese recovery method of the present invention

  Hereinafter, the present invention will be described in more detail based on examples.

  In Examples and Comparative Examples, the electrode member-containing material obtained by pulverizing batteries such as used manganese dry batteries and alkaline manganese dry batteries and removing the exterior members and the like was used. Table 1 shows the compositions of the electrode member-containing materials used in the examples and comparative examples. In addition, metal components other than those shown in Table 1 were below the detection limit.

(Quantitative determination of potassium, manganese and zinc)
The solid phase obtained in each treatment step was dissolved in a solution of 10% hydrogen peroxide in a 2 mol% aqueous sulfuric acid solution, and then filtered to collect the filtrate. The collected filtrate was subjected to quantitative chemical analysis of each element using an atomic absorption method. The liquid phase obtained in each treatment step was directly subjected to quantitative chemical analysis of each element using an atomic absorption method.
(Quantitative carbon)
The solid phase obtained in the first step was dissolved in a solution of 10% hydrogen peroxide in a 2 mol% sulfuric acid aqueous solution, and then filtered to collect the filtration residue. The amount of carbon was quantified by measuring the weight of the collected filtration residue.

Example 1
(First step)
100 g of the electrode member-containing material was dispersed in 300 ml of pure water to obtain a slurry of the electrode member-containing material. The slurry was heated to 40 ° C. with stirring, and a 10 mol% sulfuric acid aqueous solution was added to maintain pH = 4 while maintaining the temperature. While maintaining the temperature at 40 ° C. and pH = 4, the mixture was stirred for 1 hour and treated. After the treatment, filtration was performed using 5C filter paper to separate into a sulfuric acid aqueous solution (liquid phase 1) and a filtration residue (solid phase 1). The results are shown in Table 2. The obtained solid phase 1 was a mixture mainly composed of a manganese compound and carbon.

(Second step)
The sulfuric acid aqueous solution (liquid phase 1) obtained in the first step was further heated and maintained at 40 ° C., and ammonia water was added dropwise until pH = 7. The mixture was stirred for 1 hour while maintaining pH = 7. Thereafter, the resulting precipitate was filtered with 5C filter paper to separate an aqueous sulfuric acid solution (liquid phase 2) and a filtration residue (solid phase 2). The results are shown in Table 3. The obtained solid phase 2 mainly contains zinc of the liquid phase 1 obtained in the first step, and the liquid phase 2 mainly contains manganese and potassium in the liquid phase 1 obtained in the first step. Contained.

(Third process)
Aqueous ammonia was added to the aqueous sulfuric acid solution (liquid phase 2) obtained in the second step so as to maintain pH = 10, and the mixture was stirred at 40 ° C. for 1 hour for treatment. After the treatment, the resulting precipitate was filtered through 5C filter paper, and separated into a sulfuric acid aqueous solution (liquid phase 3) and a filtration residue (solid phase 3). The results are shown in Table 4. The obtained solid phase 3 contained manganese in the liquid phase 2 obtained in the second step.

  The filtration residue (solid phase 1) obtained in the first step and the filtration residue (solid phase 3) obtained in the third step were combined and recovered to obtain a manganese compound. The results are shown in Table 5. It was confirmed that the manganese compound having a low potassium concentration can be recovered at a high recovery rate by the method of the present invention.

Example 2
Manganese recovery was carried out in the same manner as in Example 1 except that the treatment pH of the first step was pH = 2, the treatment pH of the second step was pH = 9, and the treatment pH of the third step was pH = 11. went. The results are shown in Tables 2-5.

Example 3
Example except that the treatment pH of the first step was pH = 3, the temperature was 60 ° C., the treatment pH of the second step was pH = 8, the temperature was 60 ° C., the treatment pH of the third step was pH = 10, and the temperature was 60 ° C. Manganese recovery was carried out in the same manner as in No. 1. The results are shown in Tables 2-5.

Example 4
Example 3 except that 5 g of manganese dioxide (Mn content: 3.01 g, Zn content: 0 g, K content: 0.02 g) was added as an oxidizing agent to the filtrate obtained in the second step in the third step. Manganese recovery was carried out in the same manner as in No. 1. The results are shown in Tables 2-5.

Comparative Example 1
The treatment was performed in the same manner as in Example 1 except that the treatment pH of the first step was pH = 6, the treatment pH of the second step was pH = 6.5, and the treatment pH of the third step was pH = 9. Manganese recovery was performed. The results are shown in Tables 2-5.

Comparative Example 2
Example 1 except that the treatment pH in the first step was pH = 1, the temperature was 60 ° C., the treatment pH in the second step was pH = 9, the temperature was 60 ° C., the treatment pH in the third step was pH = 11, and the temperature was 60 ° C. Manganese recovery was carried out in the same manner as in No. 1. The results are shown in Tables 2-5.

Comparative Example 3
Example except that the treatment pH of the first step was pH = 5, the temperature was 60 ° C., the treatment pH of the second step was pH = 6, the temperature was 60 ° C., the treatment pH of the third step was pH = 9, and the temperature was 60 ° C. Manganese recovery was carried out in the same manner as in No. 1. The results are shown in Tables 2-5.

  By the method of the present invention, the manganese component in the used battery can be separated from potassium, zinc and the like and recovered at a high recovery rate. The recovered manganese compound can be used alone or as a mixture with manganese ore as a raw material for electrolytic manganese dioxide, and can be directly applied to existing processing equipment.

Claims (4)

Manganese oxide in the positive electrode mixture, zinc oxide in the negative electrode, and battery electrode member content containing a solution containing zinc chloride aqueous solution or potassium hydroxide aqueous solution as the main component in the electrolyte A first step of heating to 40 to 60 ° C., adding an aqueous sulfuric acid solution, and treating with 2 ≦ pH ≦ 4 to separate into a solid phase (solid phase 1) and a liquid phase (liquid phase 1), The obtained liquid phase (liquid phase 1) is maintained at 40 to 60 ° C., ammonia water is added to liquid phase 1 and treated with 7 ≦ pH ≦ 9, and further solid phase (solid phase 2) and liquid phase The second step of separating into (Liquid Phase 2), and further maintaining the obtained liquid phase (Liquid Phase 2) at 40-60 ° C., adding ammonia water to Liquid Phase 2, and treating with pH ≧ 10 The solid phase 1 and / or the solid phase 3 is recovered by the third step of making a solid phase (solid phase 3) comprising a manganese compound by Manganese method for recovering from the pond. In recovering the solid (solid phase 3) after treatment with pH ≧ 10, The method of claim 1, characterized in that treating with an oxidizing agent added. The method of claim 2 , wherein the oxidizing agent is manganese dioxide. The recovery method according to any one of claims 1 to 3 , wherein the manganese compound has a potassium concentration of 1% by weight or less.

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