Valuable metal recovery methods

Abstract

To provide a valuable metal recovery method capable of efficiently and stably recovering a valuable metal composed of cobalt and / or nickel from a feed solution containing at least one of cobalt and nickel and containing copper.SOLUTION: A valuable metal recovery method for recovering a valuable metal composed of at least one of cobalt and nickel from a feed solution containing at least one of cobalt and nickel and containing copper, the method comprising an ion adsorption step S01 for bringing the feed solution into contact with a chelate resin having a bispicolylamine group to adsorb metals in the feed solution onto the chelate resin, and a cobalt and nickel elution step S02 for eluting at least one of the cobalt and nickel adsorbed onto the chelate resin by using a sulfuric acid solution, the ion adsorption step S01 and the cobalt and nickel elution step S02 being repeatedly performed, and further comprising a copper elution step S04 for eluting copper adsorbed onto the chelate resin by using an aqueous ammonia solution according to the amount of copper adsorbed onto the chelate resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for recovering valuable metals, which recovers valuable metals consisting of at least one of cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also containing copper. [Background technology]

[0002] Valuable metals such as cobalt and nickel are contained in the leachate of nickel laterite ore, the raffinate obtained after copper is extracted from the leachate of copper ore, and waste liquids generated during the treatment of printed circuit boards, waste batteries, etc. These leachates, raffinates, and waste liquids also contain impurities such as iron, copper, and zinc in addition to cobalt and nickel. As a method for recovering cobalt and nickel from the above-mentioned leachate and waste liquid, an ion adsorption method using a chelating resin is used.

[0003] In the ion adsorption method, as described in Patent Document 1 and Non-Patent Documents 1 and 2, for example, a solution containing the metal is brought into contact with a chelating resin to adsorb the metal onto the chelating resin, and then an eluent such as an acid is passed through the chelating resin to elute the adsorbed metal. The chelating resin from which the adsorbed metal has been eluted is then reused to treat the solution.

[0004] Patent Document 1 describes a method for recovering cobalt and nickel by leaching copper ore and extracting copper ions with a solvent, followed by pretreatment of the raffinate solution by adjusting the pH and reducing iron (III) ions, and then selectively extracting copper and then cobalt and nickel using a chelating resin (ion exchange resin), and then eluting the cobalt and nickel from the chelating resin with sulfuric acid.

[0005] Non-Patent Document 1 describes a method for separating and recovering copper from a printed circuit board leachate containing a large amount of copper by adsorbing copper ions using a chelating resin having bispicolylamine groups and eluting them with sulfuric acid. Non-Patent Document 2 describes the relationship between the elution rates of the metals and the concentrations of the eluents obtained by eluting nickel with sulfuric acid and copper with an aqueous ammonia solution from a chelating resin having bispicolylamine groups to which nickel and copper have been adsorbed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2011 / 100442 [Non-patent literature]

[0007] [Non-Patent Document 1] Neto, IFF, et al., “A simple and nearly-closed cycle process for recycling copper with high purity from end life printed circuit boards” (Separation and Purification Technology, 2016), Vol. 164, 19-27. [Non-patent document 2] Ulloa, L., et al., “Split regeneration of chelating resins for the selective recovery of nickel and copper”(Separation and Purification Technology, 2020), Vol. 253, 117516. Summary of the Invention [Problem to be solved by the invention]

[0008] In Patent Document 1, the cobalt and nickel are adsorbed onto a chelating resin after an appropriate pretreatment of the element mixture solution. The cobalt is eluted by eluting the chelating resin with low-concentration sulfuric acid, and the nickel is eluted by eluting with high-concentration sulfuric acid. However, with this method, the copper adsorbed within the chelating resin is not completely eluted, but accumulates and concentrates, which can lead to a decrease in the performance of the chelating resin due to its occupancy of the ion adsorption capacity.

[0009] In Non-Patent Document 1, chelating resin is regenerated using sulfuric acid, but since the target is printed circuit board leachate containing a high concentration of copper, a high concentration (32% by mass) of sulfuric acid is required as an eluent for copper ions, and the amount of sulfuric acid used per amount of resin is also large, which increases the processing cost.

[0010] Non-Patent Document 2 reports that, after examining the concentration conditions of the eluent, the highest elution rate was obtained when 18% by mass of sulfuric acid and 3.4% by mass of aqueous ammonia were used in combination, but even under those conditions, the elution rates of nickel and copper were less than 66%. Furthermore, it reports that the nickel adsorption rate decreases when adsorption and resin regeneration are repeated, and it is presumed that the performance of the chelating resin decreases due to the accumulation and concentration of copper ions within the resin, occupying the ion adsorption capacity.

[0011] As mentioned above, the solution treatment method using a chelating resin with bispicolylamine groups is suitable for recovering cobalt and nickel. However, when copper is present in the solution, the copper ions are preferentially adsorbed onto the resin, and are not efficiently eluted by passing sulfuric acid through the resin. This has led to a problem in that the ion adsorption capacity of the resin loaded in the column decreases, as shown in Patent Document 1 and Non-Patent Document 2.

[0012] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for recovering valuable metals that can efficiently and stably recover valuable metals consisting of cobalt and nickel from a raw solution that contains at least one of cobalt and nickel and also contains copper. [Means for solving the problem]

[0013] In order to solve the above-mentioned problems, a method for recovering valuable metals according to a first aspect of the present invention is a method for recovering valuable metals consisting of at least one of cobalt and nickel from a raw solution that contains at least one of cobalt and nickel and also contains copper, the method comprising: an ion adsorption step in which the raw solution is brought into contact with a chelating resin having bispicolylamine groups to adsorb the metals in the raw solution onto the chelating resin; and a cobalt and nickel elution step in which at least one of cobalt and nickel adsorbed onto the chelating resin is eluted and recovered with a sulfuric acid solution, thereby regenerating the chelating resin; and a copper elution step in which, depending on the amount of copper adsorbed onto the chelating resin, the copper adsorbed onto the chelating resin is eluted with an aqueous ammonia solution to regenerate the chelating resin, and the ion adsorption step is carried out using the chelating resin regenerated in the copper elution step.

[0014] According to the method for recovering valuable metals of the first aspect of the present invention, an ion adsorption step in which metals in a raw solution are adsorbed onto a chelating resin, and a cobalt and nickel elution step in which at least one of cobalt and nickel adsorbed onto the chelating resin is eluted with a sulfuric acid solution, are repeatedly carried out, and a copper elution step in which copper adsorbed onto the chelating resin is eluted with an aqueous ammonia solution according to the amount of copper adsorbed onto the chelating resin, thereby regenerating the chelating resin, can be suppressed. Furthermore, since the copper elution step uses an aqueous ammonia solution, copper ions can be efficiently eluted from the chelating resin. Furthermore, since the copper elution step is performed according to the amount of copper adsorbed on the chelating resin, the amount of aqueous ammonia solution used can be reduced, and deterioration of the chelating resin due to repeated adsorption and elution procedures can be suppressed, thereby extending its lifespan.

[0015] A second aspect of the present invention provides a method for recovering valuable metals, which recovers valuable metals consisting of at least one of cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also copper, by repeatedly carrying out an ion adsorption step of bringing the raw solution into contact with a chelating resin having bispicolylamine groups to adsorb the metals in the raw solution onto the chelating resin, and a cobalt and nickel elution step of eluting and recovering at least one of cobalt and nickel adsorbed onto the chelating resin with a sulfuric acid solution to regenerate the chelating resin, and further comprising a copper elution step of eluting the copper adsorbed onto the chelating resin with an aqueous ammonia solution after carrying out the ion adsorption step and the cobalt and nickel elution step a predetermined number of times or more, thereby regenerating the chelating resin, and wherein the ion adsorption step is carried out using the chelating resin regenerated in the copper elution step.

[0016] According to the method for recovering valuable metals of aspect 2 of the present invention, an ion adsorption step in which metals in a raw solution are adsorbed onto a chelating resin, and a cobalt and nickel elution step in which at least one of cobalt and nickel adsorbed onto the chelating resin is eluted with a sulfuric acid solution are repeatedly carried out, and after the ion adsorption step and the cobalt and nickel elution step have been carried out a predetermined number of times or more, a copper elution step in which copper adsorbed onto the chelating resin is eluted with an aqueous ammonia solution to regenerate the chelating resin is also carried out. This makes it possible to suppress performance degradation caused by copper adsorption onto the chelating resin. Furthermore, since the copper elution step uses an aqueous ammonia solution, copper ions can be efficiently eluted from the chelating resin. Furthermore, since the copper elution step is performed after the ion adsorption step and the cobalt and nickel elution steps are performed a predetermined number of times or more, the amount of aqueous ammonia used can be reduced and the life of the chelating resin can be extended.

[0017] A method for recovering valuable metals according to a third aspect of the present invention is characterized in that, in the method for recovering valuable metals according to the first aspect, the copper elution step is carried out when the amount of copper adsorbed on the chelating resin is 1.25 g / LR or more. According to the method for recovering valuable metals of the third aspect of the present invention, the copper elution step is carried out when the amount of copper adsorbed on the chelating resin is 1.25 g / LR or more, thereby reliably suppressing the performance degradation caused by copper adsorption on the chelating resin. Furthermore, by appropriately carrying out the copper elution step, the amount of aqueous ammonia used can be reduced and the life of the chelating resin can be extended.

[0018] A method for recovering valuable metals according to a fourth aspect of the present invention is characterized in that, in the method for recovering valuable metals according to the second aspect, the ion adsorption step and the cobalt and nickel elution steps are each carried out two or more times, and then the copper elution step is carried out. According to the method for recovering valuable metals of the fourth aspect of the present invention, the ion adsorption step and the cobalt and nickel elution steps are each performed at least twice before the copper elution step, thereby reliably suppressing performance degradation caused by copper adsorption to the chelating resin. Furthermore, by appropriately performing the copper elution step, the amount of aqueous ammonia used can be reduced and the life of the chelating resin can be extended.

[0019] A method for recovering valuable metals according to a fifth aspect of the present invention is the method for recovering valuable metals according to any one of the first to fourth aspects, characterized in that the copper content in the raw solution is in the range of 0.0001% by mass to 1% by mass, the cobalt content is in the range of 0.001% by mass to 1% by mass, and the nickel content is in the range of 0.001% by mass to 1% by mass. According to the method for recovering valuable metals of the fifth aspect of the present invention, since the raw solution to be treated contains copper as described above, by carrying out the copper elution step at an appropriate time, it is possible to reliably suppress the performance degradation caused by copper adsorption to the chelating resin, and also to reduce the amount of aqueous ammonia used.

[0020] A method for recovering valuable metals according to a sixth aspect of the present invention is the method for recovering valuable metals according to any one of the first to fifth aspects, characterized in that the raw solution contains cobalt and nickel, and the cobalt and nickel elution step includes a cobalt elution step in which cobalt is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of less than 4% by mass, and a nickel elution step in which nickel is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of 5% by mass or more. According to the method for recovering valuable metals of aspect 6 of the present invention, the cobalt and nickel elution step includes a cobalt elution step in which cobalt is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of less than 4% by mass, and a subsequent nickel elution step in which nickel is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of 5% by mass or more, so that cobalt and nickel can be recovered separately.

[0021] A seventh aspect of the present invention is a method for recovering valuable metals according to any one of the first to sixth aspects, characterized in that the raw solution is a post-copper extraction solution discharged in the ore leaching process. According to the method for recovering valuable metals of the seventh aspect of the present invention, the raw solution is the post-copper extraction solution discharged in the ore leaching step, so that the valuable metals cobalt and nickel can be efficiently recovered from this post-copper extraction solution.

[0022] A valuable metal recovery method according to an eighth aspect of the present invention is the valuable metal recovery method according to any one of the first to sixth aspects, characterized in that the raw solution is a waste liquid from an acid leaching process of a printed circuit board. According to the method for recovering valuable metals of aspect 8 of the present invention, the raw solution is waste liquid from the acid leaching process of printed circuit boards, so that the valuable metals cobalt and nickel can be efficiently recovered from this waste liquid.

[0023] A valuable metal recovery method according to a ninth aspect of the present invention is characterized in that, in the valuable metal recovery method according to any one of the first to eighth aspects, a copper reduction step of reducing the amount of copper in the raw solution is provided prior to the ion adsorption step. According to the valuable metal recovery method of the ninth aspect of the present invention, a copper reduction step for reducing the amount of copper in the raw solution is provided before the ion adsorption step, which prevents excessive adsorption of copper ions onto the chelating resin in the ion adsorption step and prevents a rapid deterioration of the performance of the chelating resin. Furthermore, the amount of aqueous ammonia used in the copper elution step can be reduced, and deterioration of the chelating resin due to repeated adsorption and elution operations can be suppressed, thereby extending its lifespan.

[0024] A valuable metal recovery method according to a tenth aspect of the present invention is characterized in that, in the valuable metal recovery method according to the ninth aspect, the copper reduction step is a cementation step in which a metal less noble than copper is added to the raw solution, and copper ions contained in the raw solution are precipitated as metallic copper. According to the valuable metal recovery method of the tenth aspect of the present invention, the above-mentioned cementation step is carried out as the copper reduction step, so that the amount of copper in the raw solution can be reduced reliably and efficiently.

[0025] A valuable metal recovery method according to an eleventh aspect of the present invention is the valuable metal recovery method according to any one of aspects 1 to 10, characterized in that the pH of the raw solution is adjusted to within a range of 1.5 to 5.0 or less before the ion adsorption step. According to the valuable metal recovery method of aspect 11 of the present invention, the pH of the raw solution is adjusted to within a range of 1.5 to 5.0 or less before the ion adsorption step, so that cobalt and nickel in the raw solution can be efficiently adsorbed onto the chelating resin.

[0026] A valuable metal recovery method according to a twelfth aspect of the present invention is the valuable metal recovery method according to any one of the first to eleventh aspects, characterized in that the ammonia concentration in the aqueous ammonia solution used in the copper elution step is within the range of 1.7 mass % or more and 3.4 mass % or less. According to the method for recovering valuable metals of the twelfth aspect of the present invention, the ammonia concentration in the aqueous ammonia solution used in the copper elution step is set to a range of 1.7 mass % or more and 3.4 mass % or less, so that copper ions can be reliably and efficiently eluted from the chelating resin.

[0027] A method for recovering valuable metals according to a thirteenth aspect of the present invention is the method for recovering valuable metals according to any one of the first to twelfth aspects, characterized in that the sulfuric acid concentration in the sulfuric acid solution used in the cobalt and nickel elution step is in the range of 5.0 mass% or more and 50.0 mass% or less. According to the method for recovering valuable metals of aspect 13 of the present invention, the sulfuric acid concentration in the sulfuric acid solution used in the cobalt and nickel elution step is within the range of 5.0 mass% or more and 50.0 mass% or less, so that cobalt and nickel can be reliably and efficiently eluted from the chelating resin. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide a method for recovering valuable metals that can efficiently and stably recover valuable metals consisting of cobalt and nickel from a raw solution that contains at least one of cobalt and nickel and also contains copper. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a flow chart showing a method for recovering valuable metals according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a flow chart showing a method for recovering valuable metals according to a second embodiment of the present invention. [Figure 3] 1 is a graph showing the relationship between sulfuric acid concentration and the elution rate of cobalt and nickel in an example. [Figure 4] 1 is a graph showing the relationship between the cumulative amount of liquid passed and the adsorption efficiency of cobalt in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an example of a method for recovering valuable metals according to an embodiment of the present invention will be described with reference to the drawings. The method for recovering valuable metals according to this embodiment recovers valuable metals consisting of at least one of cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also containing copper, such as a leachate of nickel laterite ore, a raffinate solution obtained after copper is extracted from a leachate of copper ore, or a waste solution generated during the treatment of printed circuit boards, waste batteries, or the like. It is preferable that the copper content in the original solution is in the range of 0.0001% by mass to 1% by mass, the cobalt content is in the range of 0.001% by mass to 1% by mass, and the nickel content is in the range of 0.001% by mass to 1% by mass.

[0031] (First embodiment) Here, the method for recovering valuable metals according to the first embodiment of the present invention will be described with reference to the flow chart of FIG. As shown in FIG. 1, the method for recovering valuable metals according to this embodiment includes an ion adsorption step S01, a cobalt and nickel elution step S02, an adsorbed copper amount determination step S03, and a copper elution step S04.

[0032] (Ion adsorption process S01) A raw solution containing at least one of cobalt and nickel and also containing copper is brought into contact with a chelating resin having bispicolylamine groups, and the metals (copper, cobalt, nickel) in the raw solution are adsorbed onto the chelating resin. Here, the chelating resin having bispicolylamine groups has strong selectivity for copper, cobalt, and nickel. Furthermore, since chelating resins with bispicolylamine groups have a wide applicable pH range, they can directly process strongly acidic solutions that would have required pH manipulation in conventional methods, significantly reducing equipment and reagent costs.

[0033] The flow rate (BV) of the raw solution supplied to the ion adsorption step S01 is preferably in the range of BV 30 to 100, and for cobalt adsorption, it is even more preferable that the BV be in the range of BV 30 to 50. The flow rate is preferably in the range of SV 1.5 to 18.0. An SV of 1.5 or higher allows for efficient treatment of the raw solution, while an SV of 18.0 or lower prevents a significant decrease in the amount of metal adsorption per BV. The space velocity (SV) is the fluid flow rate per hour relative to the amount of resin. The flow rate (BV) is the volumetric equivalent of the amount of liquid passed through relative to the amount of resin, and is expressed as BV = flow rate (L) / resin volume (L).

[0034] (Cobalt and nickel elution step S02) Next, at least one of cobalt and nickel adsorbed on the chelating resin is eluted and recovered using a sulfuric acid solution, and the chelating resin is regenerated. Here, the sulfuric acid concentration in the sulfuric acid solution used in the cobalt and nickel elution step S02 is preferably in the range of 5.0 mass% or more and 50.0 mass% or less. If the sulfuric acid concentration is 5.0 mass% or more, cobalt and nickel can be efficiently eluted. Furthermore, if the sulfuric acid concentration is 50.0 mass% or less, the reaction between the sulfuric acid solution and the chelating resin can be suppressed, thereby extending the life of the chelating resin.

[0035] The sulfuric acid concentration of the sulfuric acid solution is more preferably 10.0% by mass or more, and even more preferably 20.0% by mass or more. If the sulfuric acid concentration is 10.0% by mass or more, cobalt and nickel can be eluted more efficiently. If the sulfuric acid concentration is 20.0% by mass or more, a higher elution rate for cobalt and nickel can be obtained. If the sulfuric acid concentration is 40.0% by mass or less, and even more preferably 30.0% by mass or less, the sulfuric acid reagent cost can be reduced and handling is facilitated. If the sulfuric acid concentration is 30.0% by mass or less, further reduction in reagent cost and improved handleability can be expected. The amount of liquid passing through is preferably in the range of BV 10 to 20, more preferably BV 12 or more. The liquid passing speed is preferably SV 1.5 to 18.0.

[0036] The cobalt and nickel elution step S02 may include a cobalt elution step in which cobalt is eluted and recovered using a sulfuric acid solution having a sulfuric acid concentration of less than 4.0% by mass, and a nickel elution step in which nickel is eluted and recovered using a sulfuric acid solution having a sulfuric acid concentration of 5.0% by mass or more. Cobalt can be selectively eluted using a sulfuric acid solution with a sulfuric acid concentration of less than 4.0% by mass, and then nickel can be eluted using a sulfuric acid solution with a sulfuric acid concentration of 5.0% by mass or more.

[0037] The sulfuric acid concentration of the sulfuric acid solution in the cobalt elution step is more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, and more preferably 3.0% by mass or less, and even more preferably 2.0% by mass or less. The sulfuric acid concentration of the sulfuric acid solution in the nickel elution step is more preferably 10.0% by mass or more, and even more preferably 20.0% by mass or more, and more preferably 50.0% by mass or less, and even more preferably 40.0% by mass or less.

[0038] (Adsorbed copper amount determination step S03) Next, in the cobalt and nickel elution step S02, the adsorbed cobalt and nickel are eluted, and the amount of copper adsorbed on the regenerated chelating resin (adsorbed copper amount) is determined. The amount of adsorbed copper can be calculated in the ion adsorption step S01 from the amount of copper contained in the supply liquid, the amount of copper contained in the discharge liquid, the amount of liquid passed, and the amount of resin using the following formula: Here, LR represents the volume (L) of the resin. (Amount of adsorbed copper (g / LR)) = (Amount of copper contained in discharged liquid (g / L) - Amount of copper contained in supplied liquid (g / L)) × Amount of liquid passed (L) ÷ Amount of resin (LR)

[0039] If the amount of copper adsorbed on the regenerated chelating resin (adsorbed copper amount) is less than a predetermined amount, the ion adsorption step S01 and the cobalt and nickel elution step S02 are repeatedly carried out using the regenerated chelating resin. On the other hand, if the amount of copper adsorbed on the regenerated chelating resin (adsorbed copper amount) is equal to or greater than a predetermined amount, a copper elution step 04, which will be described later, is carried out.

[0040] In this embodiment, if the amount of copper adsorbed on the regenerated chelating resin (adsorbed copper amount) is less than 1.25 g / LR, it is preferable to repeatedly perform the ion adsorption step S01 and the cobalt and nickel elution step S02, and if it is 1.25 g / LR or more, to perform the copper elution step S04.

[0041] (Copper elution process S04) If the amount of copper adsorbed on the regenerated chelating resin (adsorbed copper amount) is equal to or greater than a predetermined amount, the copper adsorbed on the chelating resin is eluted with an aqueous ammonia solution to regenerate the chelating resin.Then, the ion adsorption step S01 is carried out again using the chelating resin regenerated by eluting the copper. The amount of copper adsorbed in the chelating resin is calculated by monitoring the copper concentration in the raw solution supplied and the copper concentration in the discharged solution, and then calculating the difference between the two using the above-mentioned formula for calculating the amount of copper adsorbed.

[0042] Here, the ammonia concentration in the aqueous ammonia solution used in the copper elution step S04 is preferably in the range of 0.9% by mass or more and 6.8% by mass or less. If the ammonia concentration is 0.9% by mass or more, copper can be eluted. Furthermore, if the ammonia concentration is 6.8% by mass or less, the aqueous ammonia solution is easy to handle. Furthermore, the aqueous ammonia solution can be reused repeatedly, although this depends on the amount of copper eluted.

[0043] The ammonia concentration in the aqueous ammonia solution is more preferably 1.3% by mass or more, and even more preferably 1.7% by mass or more, and more preferably 5.1% by mass or less, and even more preferably 3.4% by mass or less. The amount of liquid passing through is preferably in the range of BV 10 to 48, more preferably in the range of BV 12 to 24. The liquid passing speed is preferably in the range of SV 1.5 to 24.0.

[0044] In this embodiment, as shown in FIG. 1, a copper content determination step S06 for determining the amount of copper in the original solution and a copper reduction step S07 may be provided. In addition, as shown in FIG. 1, this embodiment may also include a pH determination step S08 for determining the pH of the stock solution supplied to the ion adsorption step S01, and a pH adjustment step S09.

[0045] (Copper content determination step S06) The amount of copper contained in the raw solution supplied to the ion adsorption step S01 is determined. There are no particular limitations on the method for determining the amount of copper, and a measurement sample may be taken from the raw solution and the amount of copper may be measured using an existing component analysis means. If the amount of copper contained in the raw solution is less than a predetermined amount, the raw solution is supplied to the ion adsorption step S01, and if the amount of copper contained in the raw solution is equal to or greater than the predetermined amount, the copper reduction step S07 described below is carried out. In this embodiment, when the amount of copper contained in the raw solution is 0.005 mass % or more, it is preferable to perform the copper reduction step S07.

[0046] (Copper reduction process S07) In this copper reduction step S07, the amount of copper contained in the raw solution is reduced. There are no particular limitations on the means for reducing copper, and various existing methods may be applied. In this embodiment, it is preferable to carry out a cementation step in which a metal less noble than copper is added to the raw solution, and copper ions contained in the raw solution are precipitated as metallic copper.

[0047] Here, examples of the metal that is more base than copper to be added include iron, aluminum, etc. When iron is added as a metal that is more base than copper, the amount of iron added is preferably within a range of 4 g / L to 230 g / L, and when aluminum is added as a metal that is more base than copper, the amount of aluminum added is preferably within a range of 2 g / L to 110 g / L.

[0048] (pH determination step S08) The pH of the raw solution to be supplied to the ion adsorption step S01 is determined. If the pH of the raw solution is 1.5 or more and 5.0 or less, the raw solution is supplied to the ion adsorption step S01. On the other hand, if the pH of the raw solution is less than 1.5 or more than 5.0, the pH adjustment step S09 described below is carried out.

[0049] Here, when the pH of the raw solution is 5.0 or less, precipitation of cobalt and nickel together with impurities can be suppressed, whereas when the pH of the raw solution is 1.5 or more, cobalt and nickel can be efficiently adsorbed onto the chelating resin in the ion adsorption step S01. The pH of the original solution is preferably 1.5 or higher, more preferably 2.5 or higher, while the pH of the original solution is preferably 5.0 or lower, more preferably 3.5 or lower.

[0050] (pH adjustment process 09) The pH of the original solution is adjusted to within the range of 1.5 to 5.0 using an acid or base. Examples of the acid to be used include sulfuric acid and nitric acid, and examples of the base to be used include caustic soda, calcium hydroxide, and magnesium hydroxide.

[0051] The above-described process makes it possible to efficiently and stably recover valuable metals such as cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also copper.

[0052] According to the method for recovering valuable metals of this embodiment configured as described above, an ion adsorption step S01 in which metals in a raw solution are adsorbed onto a chelating resin, and a cobalt and nickel elution step S02 in which at least one of cobalt and nickel adsorbed onto the chelating resin is eluted using a sulfuric acid solution are repeatedly carried out, and the method also includes an adsorbed copper amount determination step S03 in which the amount of copper adsorbed onto the chelating resin is determined, and a copper elution step S04 in which the copper adsorbed onto the chelating resin is eluted using an aqueous ammonia solution according to the amount of copper adsorbed onto the chelating resin, thereby regenerating the chelating resin. This makes it possible to suppress performance degradation caused by copper adsorption onto the chelating resin. In addition, since the copper elution step S04 uses an aqueous ammonia solution, copper ions can be efficiently eluted from the chelating resin. Furthermore, since the copper elution step S04 is performed according to the amount of copper adsorbed on the chelating resin, the amount of aqueous ammonia solution used can be reduced and the life of the chelating resin can be extended.

[0053] In this embodiment, if the copper elution step S04 is performed when the amount of copper adsorbed to the chelating resin in the adsorbed copper amount determination step S03 is 1.25 g / LR or more, performance degradation caused by copper adsorption to the chelating resin can be reliably suppressed. Furthermore, by appropriately performing the copper elution step S04, the amount of aqueous ammonia used can be reduced and the life of the chelating resin can be extended.

[0054] Furthermore, in the present embodiment, when the cobalt and nickel elution step S02 includes a cobalt elution step of eluting and recovering cobalt with a sulfuric acid solution having a sulfuric acid concentration of less than 4 mass %, and a nickel elution step of eluting and recovering nickel with a sulfuric acid solution having a sulfuric acid concentration of 5 mass % or more, cobalt and nickel can be separated and recovered.

[0055] Furthermore, in this embodiment, if a copper content determination process S06 for determining the amount of copper contained in the raw solution and a copper reduction process S07 for reducing the amount of copper in the raw solution are performed before the ion adsorption process S01, by sufficiently reducing the amount of copper in the raw solution supplied to the ion adsorption process S01, it is possible to prevent excessive adsorption of copper ions onto the chelating resin in the ion adsorption process S01, and to prevent a sudden decrease in the performance of the chelating resin.

[0056] Furthermore, in this embodiment, when the copper reduction step S07 is a cementation step in which a metal less noble than copper is added to the raw solution and copper ions contained in the raw solution are precipitated as metallic copper, the amount of copper in the raw solution can be reliably and efficiently reduced.

[0057] Furthermore, in this embodiment, when the process includes a pH determination step S08 for determining the pH of the raw solution supplied to the ion adsorption step S01 and a pH adjustment step S09 for adjusting the pH of the raw solution to within a range of 1.5 to 5.0 or less, the cobalt and nickel in the raw solution can be efficiently adsorbed onto the chelating resin.

[0058] Furthermore, in this embodiment, when the ammonia concentration in the aqueous ammonia solution used in the copper elution step S04 is within the range of 1.7 mass % or more and 3.4 mass % or less, copper can be reliably and efficiently eluted from the chelating resin.

[0059] In addition, in this embodiment, when the sulfuric acid concentration in the sulfuric acid solution used in the cobalt and nickel elution step S02 is within the range of 5.0 mass% or more and 50.0 mass% or less, it is possible to reliably and efficiently elute cobalt and nickel from the chelating resin.

[0060] Furthermore, in this embodiment, when the copper content in the raw solution is within the range of 0.0001% by mass or more and 1% by mass or less, the cobalt content is within the range of 0.001% by mass or more and 1% by mass or less, and the nickel content is within the range of 0.001% by mass or more and 1% by mass or less, by performing the copper elution step S04 at an appropriate timing, it is possible to reliably suppress the performance degradation caused by copper adsorption to the chelating resin.

[0061] In this embodiment, when the raw solution is a post-copper extraction solution discharged in the ore leaching process, the valuable metals cobalt and nickel can be efficiently recovered from the above-mentioned post-copper extraction solution. Furthermore, in this embodiment, when the raw solution is a waste liquid from an acid leaching process of a printed circuit board, valuable metals such as cobalt and nickel can be efficiently recovered from the waste liquid.

[0062] (Second embodiment) Next, a valuable metal recovery method according to a second embodiment of the present invention will be described with reference to the flow diagram of Fig. 2. Note that the same components as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0063] As shown in FIG. 2, the method for recovering valuable metals according to this embodiment includes an ion adsorption step S01, a cobalt and nickel elution step S02, a repetition count determination step S13, and a copper elution step S04. That is, the second embodiment has a repetition count determination step S13 instead of the adsorbed copper amount determination step S03.

[0064] 2, the second embodiment may also include a copper content determination step S06 for determining the amount of copper in the raw solution and a copper reduction step S07. Also, the second embodiment may include a pH determination step S08 for determining the pH of the raw solution supplied to the ion adsorption step S01 and a pH adjustment step S09.

[0065] (Repetition number determination step S13) In this repetition number determination step S13, the number of times that the ion adsorption step S01 and the cobalt and nickel elution step S02 have been repeated is determined, and when the number of times reaches a predetermined number, the copper elution step S04 is performed. In this embodiment, it is preferable to carry out the copper elution step 04 when the number of repetitions reaches two or more.

[0066] According to the method for recovering valuable metals of this embodiment configured as described above, the ion adsorption step S01 in which metals in the raw solution are adsorbed onto a chelating resin, and the cobalt and nickel elution step S02 in which at least one of the cobalt and nickel adsorbed onto the chelating resin is eluted with a sulfuric acid solution are repeatedly carried out. In addition, in the repetition number determination step S13, the number of repetitions of the ion adsorption step S01 and the cobalt and nickel elution step S02 is determined. After the steps have been carried out a predetermined number of times or more, the copper elution step S04 in which the copper adsorbed onto the chelating resin is eluted with an aqueous ammonia solution to regenerate the chelating resin is carried out. This makes it possible to suppress performance degradation caused by copper adsorption onto the chelating resin. Furthermore, since the copper elution step S04 is carried out after the ion adsorption step S01 and the cobalt and nickel elution step S02 are carried out a predetermined number of times or more, the amount of aqueous ammonia solution used can be reduced and the life of the chelating resin can be extended.

[0067] In the valuable metal recovery method of this embodiment, when the ion adsorption step S01 and the cobalt and nickel elution steps S02 are each performed at least twice, and then the copper elution step S04 is performed, the performance degradation caused by copper adsorption to the chelating resin can be reliably suppressed. Furthermore, by appropriately performing the copper elution step S04, the amount of aqueous ammonia used can be reduced and the life of the chelating resin can be extended.

[0068] Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the technical idea of ​​the invention. [Example]

[0069] The results of experiments conducted to confirm the effectiveness of the present invention are described below. In the following examples, the concentration of the solution was measured using an inductively coupled plasma optical emission spectrometer (Hitachi PS3500 DDII).

[0070] Example 1 To simulate the situation where a large amount of copper is adsorbed onto a chelating resin, 150 mL of aqueous copper sulfate solution was passed through a column packed with 10 mL of a chelating resin with bispicolylamine groups (Sunresin, product name SEPRITE LSC495) at a flow rate of 1 mL / min, yielding a resin with 1.50 g / LR of copper adsorbed. Pure water was then passed through the column to wash away any liquid adhering to the chelating resin. After washing, 120 mL of 20% by mass sulfuric acid (BV12) was passed through the column at a flow rate of 1 mL per minute (SV6.0), followed by 120 mL of 1.7% by mass (=1N) aqueous ammonia solution (BV12) at a flow rate of 1 mL per minute (SV6.0).

[0071] The cumulative amount of copper eluted from the 20% by mass sulfuric acid solution, calculated from the column outlet concentration, was 0.54 g / LR, and the cumulative amount of copper eluted from the 1.7% by mass aqueous ammonia solution was 0.82 g / LR. The cumulative amount of copper eluted from both steps was 1.36 g / LR, which was 90.6% of the initial adsorbed copper amount. The amount of eluted copper can be calculated from the copper concentration in the solution discharged from the outlet of the column where fractions are collected at intervals, the intervals, the flow rate of the solution, and the amount of chelating resin. (Amount of eluted copper (g / LR)) = (Amount of copper contained in the effluent (g / L) × Flow rate (L / min) × Interval time (min)) ÷ Amount of resin (LR) The total amount of copper eluted from the start to the end of the passage of the sulfuric acid solution or the aqueous ammonia solution was taken as the cumulative amount of copper eluted.

[0072] Example 2 The effects of the copper reduction process (cementation process) and the pH adjustment process on the raw solution fed to the ion adsorption process were confirmed.

[0073] Test (1): 50 mL of the raffinate obtained after copper extraction from the leachate of copper ore was added with 5 mL of a chelating resin having bispicolylamine groups and stirred for 1 hour. Test (2): 0.3 g of iron powder was added to 100 mL of the raffinate obtained after copper was extracted from the leachate of copper ore, and the mixture was stirred for 1 hour. The precipitated copper was filtered off with suction to separate the solid and liquid. 50 mL of the liquid was then taken, to which 5 mL of chelating resin was added and the mixture was stirred for 1 hour. Test (3): After copper was extracted from the copper ore leachate, 4.2 mL of 14% by mass caustic soda was added to 100 mL of the raffinate solution, and the pH was adjusted from 1.2 to 2.5. 50 mL of the solution was then taken, and 5 mL of chelating resin was added and stirred for 1 hour. Test (4): 0.3 g of iron powder was added to 100 mL of the raffinate obtained after copper was extracted from the leachate of copper ore, and the mixture was stirred for 1 hour. The precipitated copper was filtered off with suction, and 3.3 mL of 14% by mass caustic soda was added to adjust the pH from 1.2 to 2.5. 50 mL of the resulting liquid was taken, and 5 mL of chelating resin was added and the mixture was stirred for 1 hour.

[0074] Table 1 shows the adsorption amounts of cobalt, nickel, and copper determined from the compositions of the solutions before and after adsorption obtained in the above tests (1) to (4).

[0075] [Table 1]

[0076] Comparing test (1) and test (2) in Table 1, it can be seen that removing copper beforehand by cementation reduces the amount of copper adsorption, while increasing the amounts of cobalt and nickel adsorption. A comparison of Test (1) and Test (3) in Table 1 shows that there is a large difference in the amount of cobalt and nickel adsorbed depending on whether or not the pH is adjusted. Chelate resins with bispicolylamine groups generally adsorb metals more easily the higher the pH, so a pH adjustment step is necessary when using low-pH liquids. Comparing tests (1) to (4) in Table 1, test (4) had the highest adsorption amounts of cobalt and nickel, indicating that the amount of cobalt and nickel adsorbed in the ion adsorption process can be maximized by performing the two processes of cementation and pH adjustment.

[0077] Example 3 Next, the sulfuric acid concentration of the sulfuric acid solution used in the cobalt and nickel elution step was examined.

[0078] 10 mL of a chelating resin having bispicolylamine groups was added to 100 mL of a sulfuric acid solution containing 200 ppm by mass of cobalt, and the mixture was stirred for 30 minutes to obtain a resin having cobalt adsorbed thereon. After separating the post-adsorption liquid from the cobalt-adsorbed resin, the adhering liquid was removed by washing with water. 50 mL of 0.5 to 5 mass % sulfuric acid was added to the washed resin, which was then stirred for 30 minutes. The elution rate (elution rate = amount of eluted cobalt ÷ amount of cobalt adsorbed on the resin) was calculated from the concentration of cobalt dissolved in the liquid. A similar test was also carried out using a sulfuric acid solution containing 200 ppm by mass of nickel, and the nickel elution rate for 1 to 10% by mass of sulfuric acid was calculated.

[0079] The above results are summarized in Figure 3. As can be seen from Figure 3, cobalt can be eluted at sulfuric acid concentrations of 0.5 mass% or more, but when the sulfuric acid concentration exceeds 5 mass%, nearly 60% of nickel is also eluted. Therefore, when efficiently eluting both nickel and cobalt, it is desirable to use sulfuric acid of 5 mass % or more.On the other hand, when separately eluting cobalt and nickel, it is desirable to use 0.5 to 4.0 mass % sulfuric acid in the first stage to elute cobalt while suppressing the elution of nickel, and to use 5.0 to 50.0 mass % sulfuric acid in the second stage to efficiently elute nickel.

[0080] Example 4 Next, the ammonia concentration of the aqueous ammonia solution used in the copper elution step was examined.

[0081] A 150 mL aqueous solution of copper sulfate with a concentration of 100 mg / L was passed through a column packed with 10 mL of a chelating resin having bispicolylamine groups at a flow rate of 1 mL per minute to obtain a resin with 1.5 g / L copper adsorbed. The liquid adhering to the chelating resin was removed by passing pure water through the column. 120 mL (BV 12) of 20% by mass sulfuric acid was passed through the washed chelating resin at a flow rate of 1 mL per minute (SV 6.0), and the elution rate for 20% by mass sulfuric acid (elution rate = amount of eluted copper / amount of copper adsorbed on the resin) was calculated from the copper concentration of the solution discharged from the column outlet.

[0082] After passing sulfuric acid through the chelating resin, 120 mL (BV 12) of an aqueous ammonia solution having the concentration shown in Table 2 was passed through the resin at a flow rate of 1 mL per minute (SV 6.0). The cumulative copper elution rate after passing the aqueous ammonia solution through the resin is shown in Table 2. Comparing tests (5) to (8) in Table 2, it can be seen that the copper elution rate reaches approximately 90% when the concentration of the aqueous ammonia solution used for elution is 1.7% by mass or more. On the other hand, when the concentration is 0.9% by mass or less, the copper elution rate is low and the regeneration of the chelating resin is insufficient.

[0083] [Table 2]

[0084] Example 5 Next, the amount of copper adsorbed on the chelating resin was examined.

[0085] A 100-mg / L copper sulfate solution (100, 125, or 150 mL) was passed through a column packed with 10 mL of chelating resin bearing bispicolylamine groups at a flow rate of 1 mL per minute, yielding resins with adsorbed copper at 1.0, 1.25, or 1.5 g / L. Pure water was passed through the column to remove any adhering liquid between the chelating resin particles. 600 mL of a sulfuric acid mixture (BV60) containing 200-300 ppm cobalt by mass was passed through the washed chelating resin and the same amount of chelating resin without adsorbed copper at a flow rate of 0.5 mL per minute (SV3.0), and the cobalt concentration of the solution discharged from the column outlet was recorded over time.

[0086] The above results are summarized in Figure 4, where the vertical axis represents the cobalt adsorption efficiency (= ratio of outlet cobalt concentration / cobalt concentration in the feed liquid) and the horizontal axis represents the flow rate (BV). As can be seen from FIG. 4, when a resin with a copper adsorption capacity of 1.25 g / LR or more is used, the cobalt adsorption efficiency begins to decrease at a flow rate of BV10 or more. Therefore, if you want to adsorb cobalt efficiently, it is desirable to carry out a copper elution step using an aqueous ammonia solution when the copper adsorption amount of the chelating resin reaches 1.25 g / LR or more.

[0087] As a result of the above confirmatory experiments, it was confirmed that the present invention can provide a method for recovering valuable metals that can efficiently and stably recover valuable metals consisting of cobalt and nickel from a raw solution that contains at least one of cobalt and nickel and also contains copper.

Claims

1. A method for recovering valuable metals comprising recovering valuable metals comprising at least one of cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also containing copper, comprising: an ion adsorption step of contacting the raw solution with a chelating resin having a bispicolylamine group to adsorb metals in the raw solution onto the chelating resin; a cobalt and nickel elution step in which at least one of cobalt and nickel adsorbed on the chelating resin is eluted and recovered using a sulfuric acid solution to regenerate the chelating resin; Repeatedly carry out the above, a copper elution step of eluting the copper adsorbed on the chelating resin with an aqueous ammonia solution in accordance with the amount of copper adsorbed on the chelating resin, thereby regenerating the chelating resin; A method for recovering valuable metals, characterized in that the ion adsorption step is carried out using the chelating resin regenerated in the copper elution step.

2. A method for recovering valuable metals comprising recovering valuable metals comprising at least one of cobalt and nickel from a raw solution containing at least one of cobalt and nickel and also containing copper, comprising: an ion adsorption step of contacting the raw solution with a chelating resin having a bispicolylamine group to adsorb metals in the raw solution onto the chelating resin; a cobalt and nickel elution step in which at least one of cobalt and nickel adsorbed on the chelating resin is eluted and recovered using a sulfuric acid solution to regenerate the chelating resin; Repeatedly carry out the above, a copper elution step of eluting the copper adsorbed on the chelating resin with an aqueous ammonia solution to regenerate the chelating resin after the ion adsorption step and the cobalt and nickel elution step have been carried out a predetermined number of times or more; A method for recovering valuable metals, characterized in that the ion adsorption step is carried out using the chelating resin regenerated in the copper elution step.

3. 2. The method for recovering valuable metals according to claim 1, wherein the copper elution step is carried out when the amount of copper adsorbed on the chelating resin is 1.25 g / L-R or more.

4. 3. The method for recovering valuable metals according to claim 2, wherein the copper elution step is carried out after the ion adsorption step and the cobalt and nickel elution step are each carried out at least twice.

5. 3. The method for recovering valuable metals according to claim 1, wherein the copper content in the raw solution is in the range of 0.0001% by mass or more and 1% by mass or less, the cobalt content is in the range of 0.001% by mass or more and 1% by mass or less, and the nickel content is in the range of 0.001% by mass or more and 1% by mass or less.

6. 3. The method for recovering valuable metals according to claim 1, wherein the raw solution contains cobalt and nickel, and the cobalt and nickel elution step comprises a cobalt elution step in which cobalt is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of less than 4% by mass, and a nickel elution step in which nickel is eluted and recovered with a sulfuric acid solution having a sulfuric acid concentration of 5% by mass or more.

7. 3. The method for recovering valuable metals according to claim 1, wherein the raw solution is a post-copper extraction solution discharged in a leaching step of an ore.

8. 3. The method for recovering valuable metals according to claim 1, wherein the raw solution is a waste solution from an acid leaching process of printed circuit boards.

9. 3. The method for recovering valuable metals according to claim 1, further comprising a copper reduction step of reducing the amount of copper in the raw solution prior to the ion adsorption step.

10. 10. The method for recovering valuable metals according to claim 9, wherein the copper reduction step is a cementation step in which a metal less noble than copper is added to the raw solution, and copper ions contained in the raw solution are precipitated as metallic copper.

11. 3. The method for recovering valuable metals according to claim 1, wherein the pH of the raw solution is adjusted to a value within the range of 1.5 to 5.0 before the ion adsorption step.

12. 3. The method for recovering valuable metals according to claim 1, wherein the ammonia concentration in the aqueous ammonia solution used in the copper elution step is in the range of 1.7 mass % or more and 3.4 mass % or less.

13. 3. The method for recovering valuable metals according to claim 1, wherein the sulfuric acid concentration in the sulfuric acid solution used in the cobalt and nickel elution step is in the range of 5.0 mass% or more and 50.0 mass% or less.

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