JP6330949B2 - Method for removing phosphorus and / or fluorine, and method for recovering valuable metals - Google Patents

Description

  The present invention relates to a method for removing phosphorus and / or fluorine when recovering valuable metals contained in a dismantled product of a waste lithium ion battery, and a method for recovering valuable metals contained in a dismantled product of a waste lithium ion battery.

  In recent years, lithium ion batteries have become widespread as light-weight and high-power secondary batteries. As a lithium ion battery, a negative electrode material in which a negative electrode active material such as graphite is fixed to a negative electrode substrate made of copper foil in a metal outer can such as aluminum or iron, and a lithium nickel oxide or cobalt on a positive electrode substrate made of aluminum foil Known are positive electrode materials to which a positive electrode active material such as lithium oxide is fixed, separators made of a resin film such as a porous film of polypropylene, an electrolyte containing lithium hexafluorophosphate, an electrolytic solution, and the like.

  One of the major uses of lithium ion batteries is hybrid vehicles and electric vehicles, and along with the life cycle of the vehicles, the mounted lithium ion batteries are expected to be discarded in the future. Many proposals have been made to reuse such used batteries (hereinafter referred to as “waste batteries”) as resources, and as a method of reusing waste batteries, a dry process in which all waste batteries are melted in a high-temperature furnace. And a wet processing method in which a waste battery is dissolved in an aqueous solution by chemicals are proposed.

  In general, the dry processing method enables mass processing at low cost, but there is a problem that the purity of the recovered valuable metal is low, and the valuable metal cannot be reused as a material for a lithium ion battery. On the other hand, in the wet processing method, it is possible to recover high-purity valuable metals, and it is possible to “use elements recovered from waste batteries to manufacture batteries”, which is an ideal resource recycling.

  As an example of the wet processing method, a method shown in Patent Document 1 is known. As shown in the process diagram of FIG. 6, this method includes a cleaning step S41 in which a waste battery disassembled material disassembled from a waste battery is washed with alcohols or water, and an electrolyte and an electrolytic solution are removed. Leaching step S42 for leaching the positive electrode active material peeled off from the positive electrode substrate with an acidic solution in the presence of fixed carbon-containing material to obtain a leaching solution and a leaching residue, and neutralizing the obtained leaching solution And neutralizing step S43 for obtaining a neutralized starch containing aluminum and copper and a neutralized solution, and nickel / cobalt recovery for separating and recovering nickel and cobalt as sulfided starch from the obtained neutralized solution to obtain a sulfided solution A step S44 and a lithium recovery step S45 for separating and recovering the lithium as a solid of lithium carbonate after concentrating the lithium in the obtained sulfurized solution by solvent extraction and back extraction are provided.

  In this method, it replaces with the neutralization process in neutralization process S43, and aluminum and copper are removed as a sulfurized starch by a sulfurization process, or it replaces with the sulfurization process in nickel / cobalt recovery process S44, and nickel and cobalt by neutralization process. Can be separated and recovered as a neutralized starch and the lithium recovery step S45 can be omitted depending on the lithium concentration.

  As described above, in the method shown in Patent Document 1, the electrolyte of the waste lithium ion battery contains lithium hexafluorophosphate and the like in the cleaning step S41 in order to recover high-purity nickel and lithium. It is necessary to remove phosphorus and fluorine reliably by increasing the processing capacity. However, this removal method is not economical because it is necessary to increase the treatment capacity in the wastewater treatment step S46, which is responsible for purification of the cleaning liquid generated in the washing step S41, in order to reliably remove phosphorus and fluorine.

  In addition, in order to reliably remove phosphorus and fluorine in the method shown in Patent Document 1, a method is also known in which a heating step is provided in place of the cleaning step S41 to remove the electrolyte and the like adhering to the waste battery disassembly. Yes. However, while this removal method is suitable for the purpose of reducing the content of phosphorus and fluorine, in order to completely remove phosphorus and fluorine, it is necessary to extremely increase the heating temperature and processing time in the heating process. Is not economical.

  As described above, as a method for recovering valuable metals from a waste battery, various methods for removing phosphorus and fluorine in the waste battery have been studied. However, operation at a lower cost is possible. In addition, a highly efficient method for removing phosphorus and fluorine is desired.

  By the way, also in the technical field of wastewater treatment, methods for removing phosphorus and fluorine in wastewater are being studied. For example, as shown in Patent Document 2 and Patent Document 3, a method is known in which phosphorus and fluorine are simultaneously precipitated using aluminum, and this method requires an aluminum ion source in order to form a precipitate with aluminum. It becomes. However, when this method is applied to a method for recovering valuable metals from waste batteries, valuable metals such as nickel are present in the leachate, so valuable metals are taken into the precipitate in the process of forming a precipitate containing aluminum. There is a problem that valuable metals cannot be selectively recovered.

JP 2007-122885 A JP 2007-190516 A JP 2002-018449 A

  Therefore, the present invention has been proposed in view of such circumstances, and is included in used lithium ion batteries, defective products of lithium ion batteries, and the like (hereinafter referred to as “waste lithium ion batteries”). When recovering valuable metals, phosphorus and fluorine are efficiently immobilized to reduce the contents of phosphorus and fluorine contained in the wastewater, and further, equipment costs and operation associated with removal of phosphorus and fluorine in wastewater treatment It is an object of the present invention to provide a method for removing phosphorus and / or fluorine that reduces costs and realizes cost reduction of operation.

  In addition, when recovering valuable metals contained in waste lithium ion batteries, the present invention recovers valuable metals efficiently by fixing phosphorus and fluorine and selectively separating valuable metals. Another object of the present invention is to provide a valuable metal recovery method capable of improving the rate.

  Furthermore, when recovering valuable metals contained in waste lithium ion batteries, the present invention can achieve both a reduction in the contents of phosphorus and fluorine contained in the waste liquid and an improvement in the recovery rate of valuable metals. Another object is to provide a method for recovering valuable metals.

  The inventors of the present invention have made extensive studies in view of the above-mentioned problems of the prior art. As a result, in the leaching process for recovering valuable metals contained in waste lithium ion batteries, the pH of the acidic solution is adjusted to a predetermined range so that the amount of aluminum eluted in the leachate is higher than the amount of phosphorus and the amount of fluorine. In the subsequent neutralization step, it was found that most of phosphorus and fluorine in the leachate can be removed as neutralized starch by adjusting the pH of the leachate obtained in the leach step to a predetermined range. However, in this removal method, valuable metals are contained in the obtained neutralized starch, and valuable metals are also removed together.

  Therefore, the present inventors selectively separate phosphorus, fluorine and valuable metals in the neutralized starch by providing a re-dissolution step for dissolving the valuable metals in the obtained neutralized starch. The present invention was completed.

  That is, the method for removing phosphorus and / or fluorine according to the present invention for achieving the above-described object is included in a negative electrode material and / or a positive electrode material of a lithium ion battery, and the component member to which phosphorus and / or fluorine is attached. In the phosphorus and / or fluorine removal method for removing phosphorus and / or fluorine when recovering valuable metals, the leachate from which at least the valuable metals, aluminum, phosphorus and / or fluorine contained in the constituent members are leached is neutralized. A neutralization step of obtaining a neutralized starch of aluminum containing phosphorus and / or fluorine, and re-dissolving valuable metals mixed in the neutralized starch from the neutralized starch by re-dissolution using an acidic solution. A dissolution step.

  In addition, the method for recovering valuable metals according to the present invention for achieving the above-described object includes a negative metal and / or a positive electrode material of a lithium ion battery, and the valuable metal contained in a component having phosphorus and / or fluorine attached thereto. In the method for recovering valuable metals, the leaching step of leaching at least valuable metals, aluminum, phosphorus and / or fluorine contained in the constituent member to obtain a leachate, and neutralizing the leachate obtained in the leaching step, A neutralization step for obtaining a neutralized solution containing valuable metals by separating as aluminum neutralized starch containing phosphorus and / or fluorine, and re-dissolving the valuable metals mixed in the neutralized starch using an acidic solution. A re-dissolution step for obtaining a re-dissolution solution containing the separated valuable metal and a recovery step for separating and recovering the valuable metal from the neutralized solution.

  According to the present invention, phosphorus and fluorine can be efficiently fixed and the amount of phosphorus and fluorine requiring wastewater treatment can be reduced, so that the scale of the wastewater treatment facility can be reduced and the wastewater treatment process can The amount of drug used can be suppressed. As a result, the present invention can greatly reduce the equipment cost and the operating cost, and can realize the cost reduction of the operation.

  In addition, according to the present invention, by fixing phosphorus and fluorine and selectively separating valuable metals, the valuable metals are efficiently recovered and the loss of valuable metals recovered from the waste lithium ion battery is greatly increased. Can be reduced. As a result, the present invention can improve the recovery rate of valuable metals.

  Furthermore, according to the present invention, phosphorus and fluorine are immobilized and valuable metals are selectively separated, thereby reducing the contents of phosphorus and fluorine contained in the waste liquid and improving the recovery rate of valuable metals. It can be compatible.

It is process drawing which showed each process for collect | recovering valuable metals from the waste lithium ion battery concerning embodiment of this invention, and showed each process for collect | recovering valuable metals from the waste lithium ion battery in Example 1. It is process drawing. FIG. 6 is a process diagram showing each process for recovering valuable metals from a waste lithium ion battery in Comparative Example 1. It is process drawing which showed each process for collect | recovering valuable metals from the waste lithium ion battery in the comparative example 2. It is the graph which showed the nickel recovery rate in Example 1, the comparative example 1, and the comparative example 2, and the phosphorus ratio sent to a waste water treatment process. It is the graph which showed the nickel recovery rate in Example 1, the comparative example 1, and the comparative example 2, and the fluorine ratio sent to a waste water treatment process. It is process drawing which showed each process for collect | recovering valuable metals from the conventional waste lithium ion battery.

Hereinafter, an embodiment of a method for removing phosphorus and / or fluorine and a method for recovering valuable metals (hereinafter referred to as “the present invention”) according to the present invention will be described below with reference to the process diagram shown in FIG. It explains in detail along an item. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.
1. 1. Outline of the present invention 2. Production process of waste battery disassembly 3. Formulation process 4. Leaching process Neutralization step 6. 6. Re-dissolution process Nickel / cobalt recovery process 8. Lithium recovery process 9. Wastewater treatment process 10. Summary

[1. Outline of the present invention]
The present invention is a method for removing phosphorus and / or fluorine, and a method for recovering valuable metals contained in a waste lithium ion battery to which the removal method is applied by a wet treatment method. More specifically, the method for removing phosphorus and / or fluorine is a method for removing unnecessary phosphorus and / or fluorine when recovering valuable metals contained in the dismantled product of the waste lithium ion battery. In the method for removing phosphorus and / or fluorine, phosphorus and fluorine that require wastewater treatment can be efficiently fixed, and the amount of chemicals consumed in the wastewater treatment step can be reduced.

  The valuable metal recovery method is a method of recovering valuable metals contained in a dismantled product of a waste lithium ion battery. In the method for recovering valuable metals, since the above-described method for removing phosphorus and / or fluorine is applied, phosphorus and fluorine can be immobilized efficiently, and only valuable metals are selectively separated and efficiently. Can be recovered.

Here, the lithium battery includes a lithium primary battery and a lithium ion secondary battery. For example, as a general configuration of a lithium ion secondary battery, a negative electrode active material that is a carbon material such as graphite is fixed to a negative electrode substrate made of copper foil in a metal outer can such as aluminum or iron. Negative electrode material, positive electrode material in which a positive electrode active material which is a lithium metal oxide such as lithium nickelate (LiNiO ₂ ) or lithium cobaltate (LiCoO ₂ ) is fixed to a positive electrode substrate made of aluminum foil, a porous film of polypropylene, etc. Separator made of resin film, electrolyte containing lithium salt such as lithium hexafluorophosphate (LiPF ₆ ), ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, cyclic carbonate, lower chain carbonate, lower fatty acid ester, etc. Known to contain an electrolyte containing an organic solvent. . Further, the lithium primary battery uses manganese oxide or the like for the positive electrode and lithium for the negative electrode.

  Moreover, a waste lithium ion battery is a defective product produced in the manufacturing process of a used or poor quality lithium ion battery or a positive electrode material constituting the battery.

  Hereinafter, a method for recovering valuable metals to which a method for removing phosphorus and / or fluorine is applied will be described in detail with reference to the process diagram shown in FIG. Here, a method for recovering valuable metals will be described. However, as described above, since this method applies a method for removing phosphorus and / or fluorine, phosphorus and / or fluorine are included in the description of the method for recovering valuable metals. Or the description of the fluorine removal method is also included.

[2. Process for dismantling waste battery]
First, in the method for recovering valuable metals, the waste lithium ion battery is heated or washed to remove the electrolyte contained in the waste lithium ion battery. However, in the method for recovering valuable metals, it is dangerous to heat or wash the waste lithium ion battery in a charged state. Therefore, prior to heating or washing, the waste lithium ion battery can be made harmless by discharging it. It is desirable to keep it.

  When the waste lithium ion battery is heated to remove the electrolytic solution, it may be heated at a temperature at which the electrolytic solution contained in the waste lithium ion battery can be removed, and may be heated at 100 ° C. to 500 ° C. Particularly preferred is 150 to 250 ° C. In the method for recovering valuable metals, the electrolyte solution can be easily removed by heating the waste lithium ion battery in this temperature range. Further, in the valuable metal recovery method, it is possible to prevent the electrolytic solution from being mixed as an impurity in a subsequent process by removing the electrolytic solution in advance.

  In the method for recovering valuable metals, it is preferable from the viewpoint of cost to remove the electrolyte contained in the waste lithium ion battery by heating. Further, in the method for recovering valuable metals, by removing the electrolytic solution contained in the waste lithium ion battery by heating, like the conventional method, before the leaching step S12, which will be described later, several stages of cleaning steps with low cost are performed. There is no need to provide.

  Further, when the waste lithium ion battery is washed to remove the electrolytic solution, alcohol or water is used. In the method for recovering valuable metals, it is preferable to use alcohols such as ethanol and methanol, or a mixture of these alcohols. In general, carbonates are known to be insoluble in water, but carbonates used as an electrolyte include ethylene carbonate. Since ethylene carbonate is arbitrarily dissolved in water, and other organic components contained in the electrolytic solution have some solubility in water, the electrolytic solution can be washed with water.

  In the method for recovering valuable metals, if the washing is not enough to remove the electrolyte, the waste lithium ion battery and the alcohol or water are separated after the first washing is completed, It is preferable to add new alcohols or water and repeat the same washing operation as the first time a plurality of times. However, in the method for recovering valuable metals, it is not economical if the number of times of cleaning is too large, and therefore it is preferable that the cleaning be performed 10 times or less.

  In the method for recovering valuable metals, the electrolytic solution contained in the waste lithium ion battery is removed by washing, so that several steps of washing steps with low cost are performed before the leaching step S12 described later, as in the conventional method. There is no need to provide a small-scale cleaning process.

  Next, in the method of recovering valuable metals, the heated or washed waste lithium ion battery is disassembled into constituent members such as a negative electrode material, a positive electrode material, and a separator using a crusher, a crusher, etc. Get. Further, in the valuable metal recovery method, after the outer can of the waste lithium ion battery is cut and disassembled into various components to obtain a waste battery disassembly, for example, one side of the waste battery disassembly becomes 30 mm square or less. Similarly, you may cut | disconnect a waste battery disassembled thing.

  In the method for recovering valuable metals, it is easy to prepare the predetermined element contained in the waste battery disassembled material at a predetermined ratio in the preparation step S11 described later by cutting the waste battery disassembled material to an appropriate size. Become. Moreover, in the method for recovering valuable metals, the content of phosphorus and fluorine contained in the waste water is controlled by preparing the predetermined elements contained in the dismantled waste battery at a predetermined ratio, and the waste water treatment step The amount of phosphorus and fluorine provided to S17 can be reduced.

In the method of recovering valuable metals, the positive electrode material separated and disassembled from the waste lithium ion battery is made of aluminum foil made of a positive electrode substrate, LiNiO ₂ that is a positive electrode active material, etc. It may be further separated into a lithium transition metal mixed oxide. That is, in the method for recovering valuable metals, the positive electrode active material is fixed to the aluminum foil even after the dismantled waste battery is produced, but the positive electrode active material is put into an acidic solution and stirred to obtain the positive electrode active material. And the aluminum foil can be separated in a solid state. This seems to be because the positive electrode active material is peeled off from the aluminum foil when the aluminum foil is eluted in a small amount.

  In the valuable metal recovery method, the obtained aluminum foil can be used as an aluminum ion source in the neutralization step S13 described later. In the method for recovering valuable metals, the aluminum foil that is the waste battery disassembly can be used as an aluminum ion source, so that it is not necessary to separately prepare aluminum as the aluminum ion source.

[3. Formulation process]
Next, as shown in FIG. 1, in the method for recovering valuable metals, the prepared dismantled product is prepared by preparing the predetermined elements contained in the dismantled waste battery separated and dismantled from the waste lithium ion battery at a predetermined ratio. Is obtained (preparation step S11). Here, the predetermined elements contained in the waste battery disassembly are aluminum, phosphorus, and fluorine. That is, the compounded dismantled product means an assembly of a plurality of dismantled waste battery materials that are selected so that aluminum, phosphorus, and fluorine contained in the waste battery disassembled material have a predetermined ratio.

  Here, the predetermined ratio of aluminum, phosphorus and fluorine in the blending step S11 is a ratio in which the amount of phosphorus is not more than the amount of aluminum and the amount of fluorine is not more than 6 times the amount of aluminum. It is.

  Specifically, in the blending step S <b> 11, it is preferable to adjust the ratio of phosphorus contained in the blended product to be in the range of 0 to 100 with respect to the aluminum amount 100. In the neutralization step S13 to be described later, the precipitation amount of phosphorus is determined by the following formula (1). When the phosphorus amount exceeds 100% with respect to the aluminum amount, that is, when phosphorus is excessively present with respect to aluminum. Excess phosphorus is not preferable because the reaction of the following formula (1) does not proceed in the direction of the arrow and cannot be removed as a neutralized starch.

2H ₃ PO ₄ + Al ₂ (SO ₄ ) ₃ +6 NaOH
→ 2AlPO ₄ ↓ + 3Na ₂ SO ₄ + 6H ₂ O (1)

  In the blending step S11, the proportion of fluorine contained in the blended product is adjusted so that it is preferably 6 times or less, more preferably 3 times or less of the amount of aluminum. In the neutralization step S13, which will be described later, the precipitation amount of fluorine is determined by the following formula (2), and when the fluorine amount exceeds three times the aluminum amount or when the sodium concentration is high under the reaction conditions with high sodium concentration, If the amount of fluorine exceeds 6 times that of aluminum, that is, if fluorine exists excessively relative to aluminum, the reaction of the following formula (2) does not proceed in the direction of the arrow, and fluorine can be removed as a neutralized starch. It is not preferable because it cannot be done.

₂ × HF + Al ₂ (SO ₄ ) ₃ + 2 × NaOH
→ 2Na _(x-3) AlF _x ↓ + 3Na ₂ SO ₄ + 2xH ₂ O (2)
(However, x in the formula (2) is 3 ≦ x ≦ 6.)

  In the blending step S11, when x in the above formula (2) is less than 3 (x <3), almost all of the fluorine is consumed according to the reaction formula of the above formula (2).

  In the blending step S11, the ratio of aluminum, phosphorus and fluorine contained in the dismantled waste battery is set so that the amount of phosphorus is not more than the amount of aluminum and the amount of fluorine is not more than 6 times the amount of aluminum. Blend to obtain a blended product.

  However, since the recovered waste lithium ion batteries have different quality depending on the brand, packing, use condition, etc., it is difficult to keep the production conditions for dismantling the waste batteries constant. In addition, since the elements and their contents contained in the waste battery disassembly vary depending on the components, the contents of aluminum, phosphorus and fluorine contained in the waste battery disassembly are measured in advance when preparing the preparation disassembly. It is necessary to keep it.

  Therefore, in the blending step S11, a waste battery disassembled material obtained by pulverizing a waste lithium ion battery using a crusher, a crusher or the like is used, and the composition of the waste battery disassembled material is analyzed for each lot. In the blending step S11, a blended and disassembled product can be produced based on the obtained analysis result so that aluminum, phosphorus and fluorine are in a predetermined ratio.

  However, since it is very difficult to analyze directly from the waste battery disassembly, in the blending step S11, the composition of the leachate obtained by immersing the waste battery disassembly in an acidic solution is analyzed for each lot. On the basis of the analysis results obtained, it is preferable to prepare the prepared and disassembled product so that aluminum, phosphorus and fluorine are in a predetermined ratio.

  In the blending step S11, by preparing a disassembled product so that aluminum, phosphorus and fluorine are in a predetermined ratio, unnecessary phosphorus and fluorine are efficiently removed in the subsequent step, and the amount of these removals is reduced. Can be controlled. Moreover, in the preparation step S11, lithium, fluorine and fluorine are reliably removed as aluminum precipitates by preparing a preparation and disassembly so that aluminum, phosphorus and fluorine are in a predetermined ratio. Only valuable metals such as nickel and cobalt can be selectively recovered.

  The aluminum contained in the waste battery disassembly is derived from the aluminum foil that is the positive electrode substrate, and the phosphorus and fluorine contained in the waste battery disassembly are lithium nickel oxide and lithium cobaltate that are the positive electrode active materials. It is derived from. In the blending step S11, since the aluminum foil can be used as an aluminum ion source, it is not necessary to separately prepare aluminum as the aluminum ion source.

[4. Leaching process]
Next, as shown in FIG. 1, in the valuable metal recovery method, the blended and dismantled product obtained in the blending step S11 is immersed in an acidic solution to obtain a leachate and a leach residue (leaching step S12). Specifically, this leaching reaction proceeds as shown in the following reaction formula (3). Here, the positive electrode active material is shown as LiNiO ₂ , but is not limited thereto.

6LiNiO ₂ + 2Al + 12H ₂ SO ₄
→ 3Li ₂ SO ₄ + 6NiSO ₄ + Al ₂ (SO ₄ ) ₃ + 12H ₂ O (3)

  In the leaching step S12, solid-liquid separation is performed after the leaching reaction is completed. In the leaching step S12, lithium, nickel, valuable metals such as cobalt, aluminum, and a small amount of impurity elements such as copper, phosphorus, and fluorine are leached into the leaching solution depending on the composition of the positive electrode active material. In the leaching step S12, the separated liquid component is a leaching solution containing valuable metals and impurities, and the solid component is a leaching residue containing impurities such as copper, carbon, and resin.

  Here, as the acidic solution used in the leaching step S12, organic acids can be used in addition to mineral acids such as sulfuric acid, nitric acid, and hydrochloric acid. In the leaching step S12, it is preferable to use sulfuric acid industrially in consideration of cost, work environment, and further recovery of valuable metals from the leaching solution in the subsequent step.

  In the leaching step S12, it is preferable to appropriately adjust the usage amount of the acidic solution to such an extent that the prepared and disassembled product can flow in the acidic solution. Therefore, in the leaching step S12, water or the redissolved solution obtained in the redissolving step S14 described later may be used as part of the acidic solution. In the leaching step S12, by using a re-dissolved liquid containing valuable metals, there is an effect of adding valuable metals that have not been recovered to the leachate obtained in the leaching step S12. In the subsequent nickel / cobalt recovery step S15, It can be recovered.

  The pH of the acidic solution used in the leaching step S12 is preferably at least 2.0 or less, and more preferably controlled to pH 0.5 to pH 1.5 in consideration of reactivity. In the leaching step S12, the pH increases as the dissolution reaction of the prepared and disassembled product proceeds. Therefore, it is preferable to supplement the acidic solution during the reaction and maintain the pH at 0.5 to 1.5.

  In the leaching step S12, the aluminum foil derived from the positive electrode substrate peeled off from the positive electrode material is eluted as aluminum ions in the leaching solution by immersing the prepared and disassembled product in an acidic solution. In the leaching step S12, this aluminum ion can be used as an aluminum ion source in the neutralization step S13 described later without supplementing aluminum from the outside.

  In the leaching step S12, the obtained leachate is analyzed, and the ratio of aluminum, phosphorus and fluorine contained in the leachate is such that the amount of phosphorus is less than the amount of aluminum and the amount of fluorine is the amount of aluminum. You may confirm whether it is 6 times or less. In the leaching step S12, based on the analysis result, a neutralization step S13 described later is performed so that the amount of phosphorus in the leachate is less than the amount of aluminum and the amount of fluorine is less than 6 times the amount of aluminum. The amount of the leachate used in the above may be adjusted as appropriate by increasing or decreasing the amount of the leachate or mixing with other leachate.

[5. Neutralization process]
Next, as shown in FIG. 1, in the valuable metal recovery method, a neutralizing agent is added to the leachate obtained in the leaching step S12 to neutralize it, and unnecessary phosphorus and fluorine are separated and removed as neutralized starch. To obtain a neutralized solution (neutralization step S13). More specifically, in the neutralization step S13, when a neutralizing agent is added to the leachate, precipitates of aluminum and copper containing phosphorus and fluorine are formed in the leachate, and after the formation of the precipitates is completed, the solids are formed. Separate the liquid. In the neutralization step S13, the separated liquid component is a neutralized solution containing valuable metals such as lithium, nickel, cobalt, and the solid component is a neutralized starch of aluminum or copper containing phosphorus or fluorine. It is. Although details will be described later, in the neutralization step S13, a precipitate containing aluminum and phosphorus, a precipitate containing aluminum and fluorine, a precipitate containing copper, and the like are obtained as the neutralized starch.

  However, in the neutralization step S13, since a small amount of valuable metals such as lithium, nickel, cobalt and the like is mixed in the neutralized starch, the valuable metals were obtained by re-dissolving in the re-dissolution step S14 described later. By using the re-dissolved liquid in the leaching step S12, valuable metals can be reliably recovered.

  The valuable metal contained in the neutralized solution or neutralized starch is derived from the positive electrode active material, aluminum contained in the neutralized starch is an aluminum foil as a positive electrode substrate, copper is a negative electrode substrate, phosphorus and fluorine are electrolytes. Derived from each. Further, in the neutralization step S13, the aluminum ion source derived from the aluminum foil leached in the leaching solution in the leaching step S12 can be used as the aluminum ion source necessary for producing the neutralized starch. There is no need to prepare aluminum separately.

  Moreover, in neutralization process S13, common neutralizing agents, such as soda ash, slaked lime, sodium hydroxide, can be used, These neutralizing agents are cheap and easy to handle.

  In the neutralization step S13, the leachate obtained in the leaching step S12 is preferably adjusted to pH 3.0 to pH 5.5 by adding a neutralizing agent. In the neutralization step S13, unnecessary phosphorus and fluorine can be separated and recovered as neutralized starch by adjusting the pH of the leachate to 3.0 to 5.5 with a neutralizing agent.

  For example, in the production of neutralized starch containing aluminum and phosphorus or fluorine, the following reaction occurs. That is, in the neutralization step S13, the reaction represented by the following formula (4) to the following formula (6) occurs, and at the same time, aluminum hydroxide is precipitated, and phosphorus and fluorine are also precipitated as an aluminum salt.

Al ₂ (SO ₄ ) ₃ + 6NaOH
→ 2Al (OH) ₃ ↓ + 3Na ₂ SO ₄ (4)
2H ₃ PO ₄ + Al ₂ (SO ₄ ) ₃ +6 NaOH
→ 2AlPO ₄ ↓ + 3Na ₂ SO ₄ + 6H ₂ O (5)
₂ × HF + Al ₂ (SO ₄ ) ₃ + 2 × NaOH
→ 2Na _(x-3) AlF _x ↓ + 3Na ₂ SO ₄ + 2xH ₂ O (6)
(However, x in the formula (6) is 3 ≦ x ≦ 6.)

  In the neutralization step S13, it is possible to precipitate phosphorus and fluorine together with aluminum by setting the pH of the leachate to 3.0 or more by adding a neutralizing agent, but when the pH of the leachate becomes less than 3.0, aluminum At the same time, phosphorus and fluorine cannot be separated and recovered as neutralized starch. In addition, in the neutralization step S13, the pH of the leachate can be set to 5.5 or less, so that precipitation of valuable metals such as lithium, nickel, cobalt and the like can be suppressed, but when the pH of the leachate exceeds 5.5, Since valuable metals precipitate simultaneously and are contained in the neutralized starch, it is not preferable.

  The neutralized starch in the neutralization step S13 is mainly composed of aluminum and has a coprecipitation effect. At pH 5.5, valuable metals that are not originally precipitated also precipitate in small amounts. Therefore, in order to reduce this loss, it is effective to add a valuable metal recovery step (remelting step S14 described later).

[6. Remelting process]
Next, as shown in FIG. 1, in the method for recovering valuable metals, an acidic solution is added to the neutralized starch obtained in the neutralization step S13, and valuable metals such as nickel and cobalt mixed in the neutralized starch are obtained. The metal is selectively separated and recovered as a re-dissolved liquid to obtain a re-dissolved residue containing unnecessary components (re-dissolving step S14). In the re-dissolution process S14, the dissolution reaction of a specific valuable metal in an acidic solution proceeds as shown in the following formula (7).

Ni (OH) ₂ + H ₂ SO ₄ → NiSO ₄ + 2H ₂ O (7)

  Here, examples of the acidic solution used in the redissolving step S14 include organic acids in addition to mineral acids such as sulfuric acid, nitric acid, and hydrochloric acid. In the re-dissolution step S14, it is preferable to use sulfuric acid industrially in consideration of cost, work environment, and the like.

  More specifically, in the re-dissolution step S14, when an acidic solution is added to the neutralized starch, valuable metals such as nickel and cobalt are dissolved in the acidic solution, and thereafter, solid-liquid separation is performed. In the re-dissolution step S14, the separated liquid component is a re-dissolution liquid containing valuable metals, and the solid component is a re-dissolution residue containing aluminum, copper, phosphorus, fluorine and the like. Therefore, in the re-dissolution step S14, most of phosphorus and fluorine in the neutralized starch can be removed as a re-dissolution residue without containing valuable metals such as lithium, nickel and cobalt.

  In the redissolving step S14, it is desirable to appropriately adjust the mixing ratio of the neutralized starch and the acidic solution so that the pH of the redissolved solution is maintained in the range of 2.0 to 5.0. This is because when the pH of the redissolved solution is less than 2.0, most of the neutralized starch, for example, aluminum precipitate, is redissolved. This is because the amount of is extremely reduced.

  In the redissolving step S14, it is desirable to avoid the formation of an extremely low pH region around the neutralized starch. Specifically, the neutralized starch was added to the re-dissolved solution of pH 2.0 to pH 5.0, and “the pH of the re-dissolved solution at the addition position was set by dropping the neutralized starch and dropping the acid from above. When the pH is no longer fluctuated from 2.0 to 5.0 even after stirring, the operation is terminated.

  Further, in the valuable metal recovery method, the obtained redissolved solution is used as an acidic solution in the leaching step S12, and the operation of reducing the valuable metal recovery loss in the neutralization step S13 can be repeated as appropriate.

  In this way, in the re-dissolution step S14, valuable metals such as lithium, nickel, and cobalt are leached into the acidic solution to obtain a re-dissolution solution, and the re-dissolution solution is used in the leaching step S12. Valuable metals that could not be recovered in step S13, that is, removed as neutralized starch can be reliably recovered. In addition, since the valuable metal contained in the redissolved solution has a low concentration, there is no possibility that the valuable metal concentration will be saturated even if used in the leaching step S12. Thus, valuable metals can be efficiently recovered without performing other recovery processes.

[7. Nickel / cobalt recovery process]
Next, as shown in FIG. 1, in the valuable metal recovery method, the sulfide liquid is separated and recovered from the neutralized liquid obtained in the neutralization step S13 to obtain a sulfide liquid (nickel / cobalt recovery step S15). More specifically, in the nickel / cobalt recovery step S15, a neutralizing agent is further added to the neutralizing solution obtained in the neutralizing step S13 while adding a sulfurizing agent, and the pH is adjusted to 2.0 to 4.0. To obtain a sulfurized starch containing nickel and cobalt and a sulfurized liquid containing lithium.

  Here, in the nickel / cobalt recovery step S15, a sulfurizing agent such as hydrogen sulfide or sodium hydrosulfide (sodium hydrogen sulfide) can be used, and in the same manner as in the neutralization step S13, soda ash, slaked lime, water A general neutralizing agent such as sodium oxide can be used.

  Specifically, in the nickel / cobalt recovery step S15, nickel ions and cobalt ions contained in the neutralized solution obtained through the neutralization step S13 become sulfided starch by a sulfurization reaction with a sulfurizing agent. For example, when nickel ions are contained in the neutralizing solution, a sulfurized starch is formed by a sulfurization reaction according to the following formula (8) or formula (9).

Ni ²⁺ + NaHS → NiS + H ⁺ + Na ⁺ (8)
Ni ²⁺ + Na ₂ S → NiS + 2Na ⁺ (9)

  The addition amount of the sulfiding agent in the nickel / cobalt recovery step S15 is, for example, 1.0 to 1.5 equivalents with respect to the content of nickel or cobalt in the neutralized solution. However, in actual operation, it may be difficult to accurately and quickly analyze the concentration of nickel and cobalt in the neutralization solution. It is more preferable to add the sulfiding agent until the potential (ORP: Oxidation-reduction Potential, hereinafter referred to as “ORP”) does not change.

  For example, when sodium sulfide is added as a sulfiding agent, the ORP value (silver-silver chloride electrode standard) of the saturated sodium sulfide solution is about -400 mV, so that the ORP value can be stably maintained. It is preferable to add. However, since sodium sulfide in the actual neutralized solution is not saturated, the ORP is stabilized on the positive side from -400 mV depending on the concentration. As a result, in the nickel / cobalt recovery step S15, nickel and cobalt leached into the neutralizing solution can be reliably sulfided, and these valuable metals can be recovered at a high recovery rate.

  In the nickel / cobalt recovery step S15, when the pH of the neutralization solution is less than 2.0, nickel and cobalt cannot be separated as sulfide starch, and the pH of the neutralization solution exceeds 4.0. This is uneconomical in that impurities are mixed into the starch and the amount of neutralizing agent used is increased.

  The temperature of the sulfurization reaction in the nickel / cobalt recovery step S15 is not particularly limited, but is 0 ° C. to 90 ° C., preferably about 25 ° C.

  As described above, in the nickel / cobalt recovery step S15, nickel and cobalt contained in the positive electrode active material of the waste lithium ion battery are recovered as nickel sulfide and cobalt sulfide (sulfurized starch) by sulfurization reaction. be able to. In the nickel / cobalt recovery step S15, the obtained sulfided starch is a sulfided starch not contaminated by phosphorus or fluorine because phosphorus and fluorine are removed in the previous step. Therefore, in the nickel / cobalt recovery step S15, valuable metals such as nickel and cobalt can be recovered from the waste lithium ion battery with high purity and a high recovery rate.

[8. Lithium recovery process]
Next, as shown in FIG. 1, in the valuable metal recovery method, after concentrating the lithium in the sulfidation liquid obtained in the nickel / cobalt recovery step S15 by solvent extraction and back extraction, the lithium is converted into a lithium carbonate solid. Separated and recovered (lithium recovery step S16).

  In the method for recovering valuable metals of the waste lithium ion battery, the lithium recovery step S16 may be performed as necessary, and the lithium recovery step S16 can be omitted as appropriate.

[9. Wastewater treatment process]
Next, as shown in FIG. 1, in the valuable metal recovery method, the final liquid after the lithium is extracted in the lithium recovery step S16 is processed (drainage processing step S17). More specifically, in the waste water treatment step S17, the final solution obtained by extracting lithium from the sulfide liquid obtained in the nickel / cobalt recovery step S15 can be treated by a normal method. Further, in the waste water treatment step S17, when not passing through the lithium recovery step S16, the sulfide liquid obtained in the nickel / cobalt recovery step S15 can be processed by a normal method.

  In the wastewater treatment step S17, phosphorus and fluorine that require wastewater treatment in the above-described final solution and sulfide solution are removed in the neutralization step S13 and the re-dissolution step S14, and are almost contained in the final solution and sulfide solution. Therefore, the scale of the wastewater treatment facility can be reduced and the amount of the chemical used in the wastewater treatment step S17 can be suppressed.

  In actual operation, it is necessary to adjust the amount of phosphorus and fluorine flowing into the wastewater treatment step S17 in accordance with the capacity of the wastewater treatment facility. Specifically, in the blending step S11, the amounts of aluminum, phosphorus and fluorine contained in the blended product are adjusted, and in the neutralization step S13, the pH value of the leachate added with the neutralizing agent is finely adjusted. In the adjustment and re-dissolution step S14, it is conceivable to finely adjust the pH value of the acidic solution added to the neutralized starch and to adjust the amount of the neutralized starch to be re-dissolved.

[10. Summary]
As described above, the valuable metal recovery method to which the phosphorus and / or fluorine removal method is applied, as shown in FIG. 1, a leaching step S12 in which a waste battery disassembly is immersed in an acidic solution to obtain a leaching solution; Neutralizing step S13 to neutralize the leachate and separate and remove phosphorus and / or fluorine together with aluminum as a neutralized starch to obtain a neutralized solution, and re-dissolve valuable metals from the neutralized starch by adding an acidic solution And a re-dissolution step S14 for separating and recovering, and a nickel / cobalt recovery step S15 for separating and recovering valuable metals from the neutralized liquid.

  Therefore, in the method for removing phosphorus and / or fluorine included in the method for recovering valuable metals, in the leaching step S12, neutralization step S13 and remelting step S14, unnecessary phosphorus and fluorine are efficiently removed using aluminum. Can be removed.

  In the method for removing phosphorus and / or fluorine, in the wastewater treatment step S17, when the final solution obtained by extracting lithium from the sulfide liquid obtained in the nickel / cobalt recovery step S15 or the lithium recovery step S16 is not used. The sulfur / fluorine contained in the nickel / cobalt recovery step S15 contains almost no phosphorus or fluorine.

  Thereby, in the removal method of phosphorus and / or fluorine, it becomes possible to reduce the scale of the wastewater treatment facility responsible for the purification of the above-described final liquid or sulfidized liquid, and the amount of chemicals consumed in the wastewater treatment step S17 is reduced. Cost reduction can be achieved.

  Further, in the valuable metal recovery method, in the preparation step S11, aluminum, phosphorus and fluorine contained in the waste battery disassembled material separated and disassembled from the waste lithium ion battery are such that the amount of phosphorus is less than the amount of aluminum and the amount of fluorine. The compounded and dismantled product is obtained by blending so that the amount of the material is 6 times or less of the amount of aluminum.

  In the valuable metal recovery method, in the neutralization step S13 and the remelting step S14, the amount of waste battery dismantled is appropriately adjusted so that the amount of phosphorus and the amount of fluorine correspond to the processing capacity of each step. be able to.

  As a result, in the phosphorus and / or fluorine removal method included in the valuable metal recovery method, it is possible to control the amount of phosphorus and fluorine that need to be processed in each step in the neutralization step S13 and the re-dissolution step S14. Thereby, in the removal method of phosphorus and / or fluorine, the amount of phosphorus and the amount of fluorine can be stably processed within a range corresponding to the scale of each processing facility.

  Further, in the valuable metal recovery method, when recovering the valuable metal from the neutralized solution or the sulfidizing solution in the nickel / cobalt recovery step S15 or the lithium recovery step S16, the amount of phosphorus and fluorine contained therein is minimized. can do. Thereby, in the valuable metal recovery method, valuable metals with high concentration and high quality can be recovered.

  In the valuable metal recovery method, in the re-dissolution step S14, a re-dissolution solution is prepared from the neutralized starch obtained in the neutralization step S13, and the obtained re-dissolution solution is used as an acidic solution in the leaching step S12. can do.

  As a result, in the valuable metal recovery method, the valuable metal contained in the re-dissolved liquid, which was not recovered in the neutralization step S13, is returned to the leaching step S12, followed by the neutralization step S13, and then the nickel / cobalt recovery step S15. And can be recovered in the lithium recovery step S16. Thereby, in the valuable metal recovery method, the loss of the valuable metal recovered from the waste lithium ion battery can be reduced, and the recovery rate of the valuable metal can be improved.

  Furthermore, in the valuable metal recovery method, the obtained aluminum foil can be used as an aluminum ion source in the neutralization step S13. As a result, in the valuable metal recovery method, the aluminum foil, which is a waste battery dismantled product, can be used as an aluminum ion source, so there is no need to separately prepare aluminum as the aluminum ion source, and the cost can be reduced. it can. Aluminum not only precipitates phosphorus and fluorine in the neutralization step S13, but also reduces the positive electrode active material in the leaching step S12 and assists leaching, greatly contributing to the cost reduction of the valuable metal recovery method. ing.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example and each comparative example, this invention is not limited to these.

Example 1
In Example 1, the waste lithium ion battery was heat-treated until the electrolyte solution disappeared, and then crushed and sieved, and separated from the positive electrode active material such as lithium nickelate and lithium cobaltate separated from the positive electrode substrate, and the negative electrode substrate. A negative electrode active material such as graphite, a positive electrode substrate that is an aluminum foil, a negative electrode substrate that is a copper foil, a separator portion made of a resin film such as a porous film of polypropylene, and the like were collected and used as raw materials.

  Next, in Example 1, as shown in FIG. 1, 30 g of the raw material (waste battery disassembled material) obtained by the above-described method was placed in 300 mL of water, and while maintaining the liquid temperature at 80 ° C. in a water bath, 64 % Sulfuric acid was added to adjust the pH to 1.0 (leaching step S12). In the leaching step S12, hydrogen was generated by leaching the metallic aluminum component contained in the raw material. In the leaching step S12, 64% sulfuric acid was intermittently supplied to maintain pH 1.0 while physically defoaming by stirring so that bubbles do not adhere to the raw material. In the leaching step S12, even when the supply of sulfuric acid is stopped, it is determined that the leaching is completed when the pH remains 1.0, and the slurry after the reaction is filtered with a filter paper (5C) to separate into a leachate and a leach residue. .

  In the leaching step S12, the nickel concentration in the obtained leachate is 14 g / L, the phosphorus concentration is 0.73 g / L, the fluorine concentration is 2.83 g / L, and the aluminum concentration is 2.7 g / L. Met. Therefore, in the leaching step S12, it was confirmed that the amount of phosphorus in the leachate was less than the amount of aluminum and the amount of fluorine was less than 6 times the amount of aluminum.

  Next, in Example 1, as shown in FIG. 1, 8 mol / L sodium hydroxide was added little by little to 294 mL of the leachate obtained in the leaching step S12 to obtain a slurry (neutralization). Step S13). In neutralization process S13, the obtained slurry was filtered with the filter paper (5C), and it isolate | separated into the neutralization liquid and the neutralization starch.

  In the neutralization step S13, the obtained neutralization solution is 294 mL in the same amount as the used leachate, the nickel concentration in the neutralization solution is 10 g / L, and the phosphorus concentration is 0.008 g / L, The fluorine concentration was 0.5 g / L. In addition, in the neutralization step S13, the dry weight of the obtained neutralized starch is 36 g, and the quality is 2.7% for nickel, 0.59% for phosphorus, and 1.9% for fluorine. Met.

  Next, in Example 1, as shown in FIG. 1, 18 g of the neutralized starch obtained in the neutralization step S13 is taken into 140 mL of water, and 64% sulfuric acid is added to the pH of 4.0 while stirring. This was added to obtain a slurry (remelting step S14). In the re-dissolution step S14, the obtained slurry was filtered with a filter paper (5C), and separated into a re-dissolution residue and a re-dissolution liquid. The dry weight of the obtained redissolved residue was 9.8 g, and the nickel quality was 1.2%. The obtained redissolved solution was 138 mL, and the nickel concentration was 2.7 g / L. This redissolved solution was mixed with the acidic solution in the leaching step S12.

  In Example 1, the amount of nickel contained in the remelted residue relative to the amount of nickel in the leachate obtained in the leaching step S12 is calculated from the amount of nickel contained in the remelted residue obtained in the remelted step S14. 0.7%. Moreover, it is 94.3% when the nickel amount contained in the neutralization liquid and the re-dissolution liquid is calculated from this nickel amount.

  Next, in Example 1, as shown in FIG. 1, 100 mL was taken from the neutralized liquid obtained by neutralization process S13, and operation of sulfidation was performed (nickel * cobalt recovery process S15).

  In the nickel / cobalt recovery step S15, as shown in FIG. 1, while supplying a 25% sodium hydrosulfide solution at a rate of 0.8 mL / min to 100 mL of the neutralization solution obtained in the neutralization step S13, pH 3.0 8 mol / L sodium hydroxide solution was added to maintain Next, in the nickel / cobalt recovery step S15, when ORP (silver-silver chloride electrode reference) reached −270 mV, the sulfidation was terminated and separated into a sulfidizing solution and a sulfided starch by a filter paper (5C).

  In the nickel / cobalt recovery step S15, the obtained sulfide solution was 110 mL, the phosphorus concentration in the sulfide solution was 0.005 g / L, and the fluorine concentration was 0.39 g / L.

  In the nickel / cobalt recovery step S15, nickel contained in the neutralized solution and the redissolved solution can be recovered. The amount of nickel that can be recovered in the nickel / cobalt recovery step S15 was 94.3% with respect to the amount of nickel in the leachate obtained in the leaching step S12.

(Comparative Example 1)
In Comparative Example 1, as shown in FIG. 2, a neutralized starch and a neutralized liquid were obtained in the same manner as in Example 1 through the leaching step S21 and in the neutralizing step S22. In Comparative Example 1, the contents of nickel, phosphorus, fluorine, and aluminum contained in the leaching solution obtained in the leaching step S21 are the contents of each substance contained in the leaching solution obtained in the leaching step S12 of Example 1. Is the same as the amount. Moreover, in Comparative Example 1, the content of each substance contained in the neutralized solution and neutralized starch obtained in the neutralization step S22 is the same as the neutralized solution obtained in the neutralization step S13 of Example 1 and the medium. It is the same as the content of each substance contained in the Japanese starch.

  In Comparative Example 1, calculating the amount of nickel contained in the neutralized starch relative to the amount of nickel in the leachate obtained in the leaching step S21 from the amount of nickel contained in the neutralized starch obtained in the neutralization step S22. 23.6%. Also. When the amount of nickel contained in the neutralizing solution was calculated from this amount of nickel, it was 76.4%.

  In Comparative Example 1, as shown in FIG. 2, since the re-dissolution step S14 in Example 1 is not performed, nickel, which is a valuable metal, is recovered only from the neutralization solution obtained in the neutralization step S22. be able to. In Comparative Example 1, as shown in FIG. 2, phosphorus and fluorine are recovered as a neutralized starch obtained in the neutralization step S22 instead of the redissolved residue obtained in the redissolution step S14 of Example 1. be able to.

  Next, in Comparative Example 1, as shown in FIG. 2, 100 mL was taken from the neutralized solution obtained in the neutralization step S22 and the sulfidation operation was performed (nickel / cobalt recovery step S23).

  In the nickel / cobalt recovery step S23, as shown in FIG. 2, while supplying a 25% sodium hydrosulfide solution at 0.8 mL / min to 100 mL of the neutralization solution obtained in the neutralization step S22, the pH of 3.0 is set. An 8 mol / L sodium hydroxide solution was added to maintain. Next, in the nickel / cobalt recovery step S23, when the ORP (silver-silver chloride electrode standard) reached −270 mV, the sulfidation was terminated, and the resultant was separated into a sulfidizing solution and a sulfided starch by a filter paper (5C). In the nickel / cobalt recovery step S23, the obtained sulfide solution was in 110 mL, the concentration of phosphorus contained in the sulfide solution was 0.005 g / L, and the fluorine concentration was 0.39 g / L.

  In the nickel / cobalt recovery step S23, nickel contained in the neutralization solution can be recovered. The amount of nickel that can be recovered in the nickel / cobalt recovery step S23 was 76.4% with respect to the amount of nickel in the leachate obtained in the leaching step S21. Therefore, when the recoverable nickel recovery rate was compared between Example 1 and Comparative Example 1, it was found that Example 1 was 17.9% higher than Comparative Example 1.

  Further, as is apparent from the results of FIGS. 4 and 5, in Comparative Example 1, although the phosphorus concentration and fluorine concentration in the sulfidizing liquid for wastewater treatment can be reduced to the same extent as in Example 1, the nickel recovery rate Is lower than Example 1. On the other hand, in Example 1, the recovery rate of nickel is high, and the phosphorous concentration and the fluorine concentration in the sulfidizing liquid for wastewater treatment can be reduced. Therefore, in Example 1, it can be said that the improvement of the recovery rate of valuable metals and the reduction of the contents of phosphorus and fluorine contained in the waste liquid can both be achieved.

(Comparative Example 2)
In Comparative Example 2, as shown in FIG. 3, in the leaching step S31, a leachate was obtained in the same manner as in Example 1. In Comparative Example 2, the contents of nickel, phosphorus, fluorine, and aluminum contained in the leaching solution obtained in the leaching step S31 are the contents of each substance contained in the leaching solution obtained in the leaching step S12 of Example 1. Is the same as the amount. In Comparative Example 2, since nickel is recovered from the leachate obtained in the leaching step S31 in the nickel / cobalt recovery step S32 described later, the amount of nickel that can be recovered in the nickel / cobalt recovery step S32 is obtained in the leaching step S31. It was 100% with respect to the amount of nickel in the obtained leachate.

  Next, in Comparative Example 2, the sulfiding operation was performed without passing through the neutralization step S13 in Example 1 (nickel / cobalt recovery step S32).

  In the nickel / cobalt recovery step S32, as shown in FIG. 3, the pH 3.0 is maintained while supplying 25% sodium hydrosulfide solution at 0.8 mL / min to 220 mL of the leachate obtained in the leaching step S31. 8 mol / L sodium hydroxide solution was added. Next, in the nickel / cobalt recovery step S32, when ORP (silver-silver chloride electrode standard) reached −270 mV, the sulfidation was terminated and separated into a sulfidizing solution and a sulfided starch by a filter paper (5C). In the nickel / cobalt recovery step S32, the obtained sulfurized solution was 240 mL, the phosphorus concentration contained in the sulfided solution was 0.43 g / L, and the fluorine concentration was 2.2 g / L.

  When the phosphorus concentration in the sulfidizing solution sent to each waste water treatment step was compared between Example 1 and Comparative Example 2, it was found that Example 1 was 0.425 g / L less than Comparative Example 2. Therefore, in Example 1, it turns out that the phosphorus density | concentration in the sulfide liquid which performs waste water treatment can be reduced, and it is thought that the equipment cost of waste water treatment can be reduced by this.

  Moreover, when the fluorine concentration in the sulfidizing liquid sent to each waste water treatment process was compared between Example 1 and Comparative Example 2, it was found that Example 1 was 1.81 g / L less than Comparative Example 2. Therefore, in Example 1, it turns out that the fluorine density | concentration in the sulfide liquid which performs waste water treatment can be reduced, and it is thought that the equipment cost of waste water treatment can be reduced by this.

  Further, as apparent from the results of FIGS. 4 and 5, in Comparative Example 2, although the nickel recovery rate is high, the phosphorus concentration and the fluorine concentration in the sulfidizing liquid for waste water treatment cannot be reduced. On the other hand, in Example 1, the recovery rate of nickel is high, and the phosphorous concentration and the fluorine concentration in the sulfidizing liquid for wastewater treatment can be reduced. Therefore, in Example 1, it can be said that the improvement of the recovery rate of valuable metals and the reduction of the contents of phosphorus and fluorine contained in the waste liquid can both be achieved.

Claims (11)

Phosphorus and / or fluorine removal method for removing phosphorus and / or fluorine when recovering valuable metal contained in a component member which is a negative electrode material and / or positive electrode material of lithium ion battery and to which phosphorus and / or fluorine is adhered In
Neutralizing the leachate from which at least the valuable metal, aluminum, phosphorus and / or fluorine contained in the constituent member has been leached to obtain a neutralized starch of aluminum containing phosphorus and / or fluorine; and
A method for removing phosphorus and / or fluorine, comprising a re-dissolution step of re-dissolving valuable metals mixed in the neutralized starch using an acidic solution and separating the valuable metal from the neutralized starch. In the neutralization step, the leachate is neutralized at pH 3.0 to pH 5.5,
The method for removing phosphorus and / or fluorine according to claim 1, wherein in the re-dissolution step, the valuable metal is separated into a liquid having a pH of 2.0 to 5.0.   3. The method for removing phosphorus and / or fluorine according to claim 1, wherein the constituent members are prepared so that aluminum, phosphorus and fluorine are in a predetermined ratio.   The amount of phosphorus (mole) is less than the amount of aluminum (mole) and the amount of fluorine (mole) is less than 6 times the amount of aluminum (mole). 4. The method for removing phosphorus and / or fluorine according to 3. In the method for recovering a valuable metal, which is a negative electrode material and / or a positive electrode material of a lithium ion battery and recovers a valuable metal contained in a constituent member to which phosphorus and / or fluorine is attached,
A leaching step of leaching at least a valuable metal, aluminum, phosphorus and / or fluorine contained in the constituent member to obtain a leaching solution;
Neutralizing the leachate obtained in the leaching step and separating it as a neutralized starch of aluminum containing phosphorus and / or fluorine to obtain a neutralized solution containing valuable metals;
A re-dissolution step of re-dissolving the valuable metal mixed in the neutralized starch using an acidic solution to separate the valuable metal from the neutralized starch, and obtaining a re-dissolved solution containing the separated valuable metal;
And a recovery step of separating and recovering the valuable metal from the neutralized solution.   6. The valuable metal recovery method according to claim 5, wherein the redissolved solution is used as an acidic solution in the leaching step. In the neutralization step, the leachate is neutralized at pH 3.0 to pH 5.5,
The method for recovering a valuable metal according to claim 5 or 6, wherein in the re-dissolution step, the valuable metal is separated into a liquid having a pH of 2.0 to 5.0.   The method for recovering a valuable metal according to any one of claims 5 to 7, wherein the constituent members are prepared so that aluminum, phosphorus, and fluorine are in a predetermined ratio.   The amount of phosphorus (mole) is less than the amount of aluminum (mole) and the amount of fluorine (mole) is less than 6 times the amount of aluminum (mole). The method for recovering valuable metals according to 8.   The valuable metal recovery method according to any one of claims 5 to 9, wherein a heated component is used in the leaching step.   The valuable metal recovery method according to any one of claims 5 to 9, wherein the leaching step uses a structural member washed with alcohol or water.

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