Metal collecting device, method for collecting metal, element analyzer, and method for analyzing element

Abstract

To provide a metal collecting device and a method for collecting metal from a solution containing noble metal elements, the device and the method sensitively determining the amount of noble metal in a processing liquid after metal is collected from the solution, by an in-situ analysis and an online analysis without requiring a pre-treatment.SOLUTION: To achieve the above object, the metal collecting device includes: a thin film generation unit for forming a processing liquid obtained by collecting metal from a solution into a thin film flow; an excitation light radiation unit for radiating collected laser beams to the thin film flow; a divided light detection unit for dividing light emitted from plasma generated on the thin film flow and detecting divided light; and a noble metal element amount determination unit for calculating the concentration of remaining noble metal element in the processing liquid on the basis of the result of detection by the divided light detection unit. According to the present invention, an in-situ analysis and an online analysis are performed on the processing liquid and the amount of the noble metal element can be rapidly and sensitively determined.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a metal recovery apparatus and a metal recovery method. More specifically, the present invention relates to a metal recovery apparatus and a metal recovery method characterized by online quantification of precious metal elements remaining in a treatment solution after precious metal recovery. The present invention also relates to an elemental analysis apparatus and method, and more particularly to an elemental analysis apparatus and method that enable stable and continuous quantification of precious metal elements contained in an acidic solution containing at least hydrochloric acid, sulfuric acid, or aqua regia. [Background technology]

[0002] In recent years, there has been growing interest in recycling from the perspective of effective resource utilization and prevention of environmental pollution. For example, used small electronic devices and small household appliances contain useful metal elements (precious metals and rare metals), and are treated as metal resources, also known as urban mines, and are recycled (metal recovery).

[0003] Here, in the recycling process of precious metals (precious metal recycling business), it is necessary to measure the concentration of precious metals in the process of recovering precious metals from dissolved solutions or waste liquids. In the precious metal recycling business, various spectroscopic analysis methods are used to measure the concentration of precious metals. For example, Patent Document 1 describes a method for recovering precious metals from electrode materials for fuel cells, in which precious metal components are extracted by wet leaching, and then the content of the precious metals remaining in the solid residue is measured using X-ray fluorescence analysis. Furthermore, Non-Patent Document 1 describes the results of a comparison of analytical values ​​(quantitative values) obtained by several analytical methods for metal resource analysis, including a measurement method based on a Ministry of the Environment Notification (Ministry of the Environment Notification No. 19) and an analytical method for rare metals proposed in 2010 by the Material Flow Study Group of the Japan Society of Material Cycles and Waste Management. The quantitative means used in each analytical method include optical emission spectroscopy (ICP optical emission spectroscopy) using high-frequency inductively coupled plasma (ICP), as well as ICP mass spectrometry, atomic absorption spectrometry, and absorptiometry. It is known that a liquid film generating nozzle is used when generating a dye laser (liquid laser). For example, Patent Document 2 describes an ultra-thin film jet nozzle with a tip in which one flat surface of a cylinder is cut into a cone and the other flat surface of the same cylinder is cut into a V-shaped groove (claim for utility model registration). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-100908 [Patent Document 2] Microfilm of Utility Model Application No. 1-38214 (Utility Model Application No. 2-129755) [Non-patent literature]

[0005] [Non-Patent Document 1] Shigenori Iino, Satoshi Mogi, and Kentaro Miyawaki, "Considerations on analytical methods for metal resources in the fields of environment and refining," Journal of the Japan Society of Material Cycles and Waste Management, Vol. 27, pp. 176-187, 2016. Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Document 1 and Non-Patent Document 1, inductively coupled plasma (ICP) optical emission spectroscopy (hereinafter referred to as "ICP-OES") and X-ray fluorescence analysis (hereinafter referred to as "XRF") are commonly used analytical methods in precious metal recycling businesses. ICP-OES quantitatively analyzes dissolved elements by dividing and diluting the target solution, spraying it offline with argon gas to plasma-excite the target elements, and observing the light emission of the excited atoms and ions. The analytical equipment used for ICP-OES is relatively large, requires an argon gas supply as an auxiliary facility, and is a batch-type analytical method that requires appropriate pretreatment. Furthermore, XRF is time-consuming, particularly for measuring elements in solution, and is therefore not suitable for rapid in-situ analysis. In other words, in conventional precious metal recycling businesses, it has been difficult to determine the concentration of precious metal elements in the precious metal recycling process in situ or online. However, to accurately and quickly grasp the progress and efficiency of precious metal recycling processes, an analytical method is required that can accurately measure the dissolved precious metal elements in solutions such as dissolution liquids and waste liquids, both in situ and online. In particular, the ability to measure the concentration of the remaining precious metals in the treatment liquid after precious metal recovery with high sensitivity and online will enable the efficiency of the entire precious metal recycling process to be improved.

[0007] On the other hand, laser-induced breakdown emission spectroscopy (hereinafter referred to as "LIBS") is a technique that allows for rapid, in-situ elemental analysis. LIBS performs elemental analysis by converting the irradiated area of ​​a sample into plasma using high-energy-density laser irradiation, generating excited atoms or ions, and measuring the wavelength and intensity of element-specific light emitted by these excited atoms or ions as they de-excite. This method has attracted attention in recent years because it does not require pretreatment.

[0008] Based on its measurement principle, LIBS can measure any sample, regardless of its form, whether it be gas, liquid, or solid. However, it is known that the luminous plasma generated by laser irradiation varies greatly depending on the sample form. In particular, when applied to liquid samples, if the sample is still water or a liquid column, the luminous plasma has a short lifetime and the observed signal becomes unstable, making it difficult to analyze with high sensitivity. Furthermore, when using LIBS, it is known that the presence of elements other than the target element can affect quantification, requiring consideration and measures depending on the components contained in the sample.

[0009] Therefore, the object of the present invention is to provide a metal recovery device and a metal recovery method that, in the case of recovering metals from a solution containing precious metal elements, enables highly sensitive quantitative determination of the precious metal concentration in the treatment liquid obtained by recovering metals from the solution by on-site analysis or online analysis without the need for pretreatment. Additionally, an object of the present invention is to provide an elemental analysis apparatus and an elemental analysis method that enable highly sensitive measurement without the need for pretreatment when the liquid sample to be measured is an acidic solution containing at least a precious metal element and hydrochloric acid, sulfuric acid, or aqua regia. [Means for solving the problem]

[0010] As a result of extensive research into the above-mentioned problems, the inventors discovered that by providing a configuration based on LIBS for measuring the concentration of precious metal elements in a solution, it becomes possible to recover metals and perform elemental analysis in a highly sensitive and rapid manner in situ and online analysis, and thus completed the present invention. That is, the present invention provides the following metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method.

[0011] The metal recovery device of the present invention, which solves the above-mentioned problems, is a metal recovery device that recovers metals from a solution containing precious metal elements, and is characterized by comprising: a thin film flow generation unit that converts the treatment liquid obtained by recovering metals from the solution into a thin film flow; an excitation light irradiation unit that irradiates the thin film flow with focused laser light; a spectroscopic detection unit that detects by spectroscopy the light emitted from plasma generated on the thin film flow by the laser light irradiated from the excitation light irradiation unit; and a precious metal element quantification unit that calculates the concentration of precious metal elements remaining in the treatment liquid based on the detection results of the spectroscopic detection unit. In metal recovery, in order to efficiently recover precious metal elements, it is necessary to measure and understand whether or not precious metal elements remain in the treatment solution after metal recovery. Conventionally, to measure the concentration of precious metals remaining in such treatment solutions, methods such as ICP-OES and XRF have been used, which require pretreatment and sampling, and require time-consuming measurements, making in-situ and online analysis difficult. On the other hand, this feature allows for LIBS-based analysis of the processing solution, which allows for both in-situ and online analysis, enabling rapid and highly sensitive measurement (quantitation) of the concentration of precious metal elements in the processing solution. This allows for a significant reduction in processing time (analysis) for metal recovery, leading to significant cost savings. Furthermore, since it is possible to quickly determine the concentration of precious metal elements remaining in the processing solution, it becomes easier to automate operations related to improving the recovery rate of precious metal elements, such as circulating the processing solution and subjecting it to metal recovery processing again.

[0012] Furthermore, the metal recovery method of the present invention for solving the above-mentioned problems is a metal recovery method for recovering metals from a solution containing precious metal elements, and is characterized by comprising: a thin film flow generation step for converting a treatment liquid obtained by recovering metals from the solution into a thin film flow; an excitation light irradiation step for irradiating the thin film flow with focused laser light; a spectroscopic detection step for detecting by spectroscopy the light emitted from plasma generated on the thin film flow by the laser light irradiated in the excitation light irradiation step; and a precious metal element quantification step for calculating the concentration of precious metal elements remaining in the treatment liquid based on the detection results of the spectroscopic detection step. This feature allows for LIBS-based analysis of the processing solution, which allows for both in-situ and online analysis, enabling rapid and highly sensitive measurement (quantitation) of the concentration of precious metal elements in the processing solution. This allows for a significant reduction in the processing (analysis) process time for metal recovery, resulting in significant cost savings. Furthermore, since it is possible to quickly determine the concentration of precious metal elements remaining in the processing solution, it becomes easier to automate processes related to improving the recovery rate of precious metal elements, such as circulating the processing solution and subjecting it to metal recovery processing again.

[0013] In addition, the elemental analysis apparatus of the present invention for solving the above-mentioned problems comprises a thin film flow generation unit that converts a liquid sample containing a precious metal element into a thin film flow, an excitation light irradiation unit that irradiates the thin film flow with focused laser light, and a spectroscopic detection unit that detects light emission from plasma generated on the thin film flow by the laser light irradiated from the excitation light irradiation unit through spectroscopy, and is characterized in that the liquid sample is an acidic solution containing at least hydrochloric acid, sulfuric acid, or aqua regia. In general, it is known that in LIBS analysis, the presence of elements other than the element being measured can affect the quantification. On the other hand, according to this feature, when the liquid sample to be measured is an acidic solution containing at least a precious metal element and hydrochloric acid, sulfuric acid, or aqua regia, by forming the liquid sample into a thin film flow, it becomes possible to perform elemental analysis based on LIBS, which enables highly sensitive measurement without the need for pretreatment. In particular, solutions containing precious metal elements generated during metal recovery processes generally undergo acid dissolution, although this varies depending on the raw materials, and become strongly acidic, containing hydrochloric acid, sulfuric acid, or aqua regia. Therefore, the elemental analyzer of the present invention is suitable for use as an analyzer for performing elemental analysis on liquid samples containing precious metal elements in metal recovery.

[0014] In one embodiment of the elemental analyzer of the present invention, the thin film flow generating unit is provided with a thin film flow generating nozzle made of an acid-resistant material. This feature prevents corrosion and deterioration of the nozzle of the thin film flow generating unit due to the sample solution being strongly acidic, containing at least hydrochloric acid, sulfuric acid, or aqua regia, and allows for stable and continuous quantification. In particular, this feature enables stable in-situ and online analysis of precious metal elements remaining in the treatment solution after precious metal recovery.

[0015] In one embodiment of the elemental analyzer of the present invention, the acid-resistant material of the thin film flow generating section is one selected from the group consisting of quartz glass, ceramic, and fluororesin. This feature makes it possible to obtain a nozzle for generating a thin film flow using a material that is not only highly acid-resistant but also easy to process and has sufficient strength, which enables the continuous generation of a stable thin film flow and enables more stable in-situ and online analysis.

[0016] In addition, one embodiment of the elemental analyzer of the present invention is characterized in that the noble metal element contained in the liquid sample is one or more selected from the group consisting of gold, silver, ruthenium, rhodium, palladium, and platinum. This feature enables stable quantitative determination of precious metals that are industrially and commercially valuable, and is particularly suitable for use in determining the amount of precious metal elements remaining in the treatment solution after precious metal recovery.

[0017] Furthermore, the elemental analysis method of the present invention for solving the above-mentioned problems comprises a thin film flow generation step of converting a liquid sample containing a precious metal element into a thin film flow, an excitation light irradiation step of irradiating the thin film flow with focused laser light, and a spectroscopic detection step of detecting light emission from plasma generated on the thin film flow by the laser light irradiated in the excitation light irradiation step through spectroscopy, wherein the liquid sample is an acidic solution containing at least hydrochloric acid, sulfuric acid, or aqua regia. According to this feature, when the liquid sample to be measured is an acidic solution containing at least a precious metal element and hydrochloric acid, sulfuric acid, or aqua regia, by forming the liquid sample into a thin film, it becomes possible to perform elemental analysis based on LIBS, which enables highly sensitive measurement without pretreatment. In particular, solutions containing precious metal elements generated during metal recovery processes generally undergo acid dissolution and become strongly acidic, containing hydrochloric acid, sulfuric acid, or aqua regia. Therefore, the elemental analysis method of the present invention is suitable for use as an analytical method for performing elemental analysis on liquid samples containing precious metal elements in metal recovery. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a metal recovery device and a metal recovery method that, in the case of recovering metals from a solution containing precious metal elements, enable highly sensitive quantitative determination of the precious metal concentration in the treatment liquid obtained by recovering the metal from the solution by in situ analysis or online analysis without the need for pretreatment. In addition, the present invention can provide an elemental analysis apparatus and an elemental analysis method that do not require pretreatment and enable highly sensitive measurements when the liquid sample to be measured is an acidic solution containing at least a precious metal element and hydrochloric acid, sulfuric acid, or aqua regia. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic explanatory diagram of a metal recovery device according to an embodiment of the present invention. [Figure 2] 1 is a schematic explanatory diagram of an elemental analysis means in a metal recovery apparatus according to an embodiment of the present invention. [Figure 3] 1 shows a calibration curve (measurement object: gold (Au)) created by elemental analysis means in a metal recovery device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method according to the present invention will be described in detail with reference to the drawings. Note that the metal recovery method in the present invention is substituted for the description of the operation of the metal recovery apparatus in the present invention. Also, the elemental analysis method in the present invention is substituted for the description of the operation of the elemental analysis apparatus in the present invention. The metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method described in the embodiments are merely examples used to explain the metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method of the present invention, and are not limited to these.

[0021] [Metal recovery equipment] FIG. 1 is a schematic explanatory diagram showing the structure of a metal recovery device according to an embodiment of the present invention. As shown in FIG. 1, the metal recovery device 1 of this embodiment is for recovering a precious metal element R from a metal source M, and includes a recovery section 10 that recovers the metal from a solution W1 containing the precious metal element R, and an elemental analysis means 20 that is provided downstream of the recovery section 10 and that quantifies the amount of the precious metal element R contained in the treatment liquid W2 discharged from the recovery section 10. Furthermore, the metal recovery device 1 of this embodiment may have various additional equipment for carrying out processes generally performed in precious metal recycling businesses. For example, the device may be provided with a receiving section 30 in the upstream of the recovery section 10 that collects and receives the metal source M, and an evaluation section 40 that evaluates the content of the precious metal element R in the metal source M received in the receiving section 30, while a refining section 50 in the downstream of the recovery section 10 that purifies the recovered precious metal element R.

[0022] The metal source M in this embodiment may be solid or liquid, and examples thereof include recycled precious metal materials such as used small electronic devices and small home appliances, as well as waste liquids containing precious metal elements R discharged from manufacturing and experimental processes in factories, research facilities, etc. The precious metal element R contained in the metal source M and to be recovered is selected from the group consisting of gold (Au), silver (Ag), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and platinum (Pt), which are called platinum group metals. Elements include In particular, the precious metal element R in the present invention preferably includes at least one selected from the group consisting of gold, silver, ruthenium, rhodium, palladium, and platinum, which makes it possible to recover and effectively utilize precious metals of high industrial and commercial value.

[0023] The entire metal recovery device 1 will be described with reference to Figure 1. Note that the metal recovery device 1 in this embodiment only needs to include at least a recovery section 10 and elemental analysis means 20, and other components may be omitted. As shown in FIG. 1 , the metal recovery apparatus 1 of this embodiment receives a metal source M containing a precious metal element R to be recovered through a receiving section 30, and introduces the metal source M into an evaluation section 40 via a line L1. After the evaluation section 40 evaluates (analyzes) the content of the precious metal element R in the metal source M, the metal source M is introduced into a recovery section 10 via a line L2, and the precious metal element R is recovered from the metal source M (solution W1 containing the precious metal element R) that has been evaluated. The recovered precious metal element R is introduced into a purification section 50 via a line L3, where the precious metal element R is refined and commercialized. Meanwhile, the treatment solution W2 from which the precious metal element R has been recovered in the recovery section 10 is discharged via a line L4. At this time, the concentration of the precious metal element R remaining in the treatment solution W2 is measured by an elemental analysis means 20.

[0024] Each component of the metal recovery device 1 will be described below. First, the metal source M from which the contained metal (precious metal element R) is to be recovered is received by the receiving unit 30. The receiving unit 30 may also have a function of attaching information related to management, such as the type of the received metal source M and the date and time of receipt.

[0025] Next, the evaluation unit 40 evaluates the content of the precious metal element R in the metal source M. In particular, in the precious metal recycling business, it is necessary to consider the profitability of metal recovery. Therefore, it is desirable to measure the content of the precious metal element R in the metal source M using the evaluation unit 40 and evaluate whether the cost required for metal recovery is worth it. As mentioned above, the evaluation unit 40 can be omitted.

[0026] At this time, if the metal source M is in a liquid state, the content of the precious metal element R is measured in the state as received or after simple pretreatment such as filtration. On the other hand, if the metal source M is in a solid state, it is crushed and fired as necessary, and then dissolved in an acid or alkali solution to become a liquid, and the content of the precious metal element R is measured. The analytical means for measuring the content of the precious metal element R in the evaluation unit 40 is not particularly limited as long as it is a highly accurate analytical method for accurately estimating the profitability of recovering the metal from the metal source M. For example, in addition to analysis using known analytical equipment that requires pretreatment and sampling and takes measurement time, such as analysis based on a gravimetric method or various known spectroscopic analyses (ICP-OES, XRF, atomic absorption spectrometry, etc.), but that enables highly accurate quantification, rapid and highly sensitive analysis using the elemental analysis means 20 described below can be used. In particular, when the metal source M is a liquid, it is preferable to perform monitoring using an elemental analysis means 20 capable of online analysis, as shown in Figure 1. By similarly applying the elemental analysis means 20 to the evaluation section 40 in addition to the recovery section 10 described below, the precious metal content before recovery can be evaluated quickly and with high sensitivity, making it possible to achieve significant time and cost reductions in the entire process related to metal recovery. Alternatively, including when the metal source M is a solid, it may be used to continuously monitor the solution W1 before metal recovery. Furthermore, the evaluation of the content of the precious metal element R in the evaluation unit 40 may be performed as needed, in addition to continuous monitoring. In this case, it is preferable to use an analysis means that enables analysis only when necessary for the evaluation unit 40. For example, an elemental analysis means 20 and an elemental analysis apparatus equipped with the elemental analysis means 20, which do not require pretreatment, are easily miniaturized as an apparatus configuration, and are portable, can be mentioned.

[0027] The recovery unit 10 is for recovering metal from a solution W1 containing a precious metal element R. Here, if the metal source M is in a liquid state, the metal source M itself is treated as the solution W1. On the other hand, if the metal source M is in a solid state, it is treated in the same manner as in the evaluation unit 40 described above, and the resulting acid or alkaline solution is treated as the solution W1. In other words, when the evaluation unit 40 is provided, the metal source M that has been evaluated in the evaluation unit 40 becomes the solution W1 containing the precious metal element R in the present invention.

[0028] The recovery unit 10 in this embodiment is not particularly limited as long as it can recover the precious metal element R dissolved in the solution W1. Examples of recovery means in the recovery unit 10 include recovery using a chemical reaction (precipitation) by adding a chemical such as a reducing agent or a precipitant or a base metal (iron, zinc, etc.) to the solution W1 (precipitation separation, cementation, etc.), recovery by adding an adsorbent to the solution W1 (adsorption), and recovery by depositing the precious metal element R on the cathode by placing an electrode in the solution W1 and applying a direct current (electrolysis).

[0029] The precious metal elements R recovered in the recovery section 10 are then introduced into the refining section 50, where they are treated until they reach a purity suitable for reuse. The refining section 50 may be any section capable of increasing the purity of the recovered precious metal element R, and examples thereof include repeating the same recovery means as in the recovery section 10, or selectively extracting ions of the precious metal element R by solvent extraction using an organic solvent and an extractant. Furthermore, the precious metal elements R whose purity has been increased in the refining section 50 are formed (commercialized) according to the intended use for reuse, and are put to effective use.

[0030] On the other hand, the treated liquid W2 after the precious metal elements R are recovered in the recovery section 10 is discharged from the recovery section 10 via a route (line L4) separate from the refining section 50. At this time, in order to efficiently recover the precious metal elements R, it is necessary to measure and understand whether or not the precious metal elements R remain in the processing liquid W2.

[0031] The metal recovery device 1 in this embodiment is provided with an elemental analysis means 20 that measures the concentration of the precious metal element R remaining in the treatment liquid W2 discharged from the recovery section . Conventionally, the concentration of precious metals remaining in the treatment solution W2 has been measured using ICP-OES or XRF analysis, but this requires pretreatment and sampling, and the measurement takes time, making it difficult to perform in-situ or online analysis. On the other hand, the elemental analysis means 20 in this embodiment is an analysis means based on LIBS that is capable of in-situ analysis and online analysis, and is capable of quickly and sensitively measuring (quantifying) the concentration of the precious metal element R in the treatment liquid W2 discharged from the recovery section 10. This makes it possible to significantly shorten the time required for analysis during metal recovery, and also to achieve significant cost reductions.

[0032] The elemental analysis means 20 in this embodiment will be described in detail below. FIG. 2 is a schematic explanatory diagram showing the structure of the elemental analysis means in the metal recovery apparatus of this embodiment. The elemental analysis means 20 in this embodiment includes a thin film flow generating unit 210, an excitation light irradiating unit 220, a spectroscopic detection unit 230, and a precious metal element quantifying unit 240. The elemental analysis means 20 in this embodiment is connected to a line L4 through which the treatment liquid W2 discharged from the recovery unit 10 is transported. In Fig. 2, the arrow indicates the flow direction of the treatment liquid W2, and the dashed dotted line indicates a connection that allows input and output or control.

[0033] The elemental analysis means 20 is provided with a structure based on LIBS. LIBS (Laser-Induced Breakdown Spectroscopy) is a type of spectroscopic analysis that uses a laser. In LIBS, a focused laser beam is irradiated onto the object to be measured (sample). Plasma (light-emitting plasma) is then generated at the point of irradiation with the laser beam, and excited atoms or ions are generated within the plasma. When these excited atoms or ions are de-excited, they emit light of wavelengths specific to each atom or ion. The wavelength and intensity of the light emitted from this light-emitting plasma (hereinafter referred to as "plasma light") are measured to qualitatively and quantitatively characterize the sample.

[0034] On the other hand, when measuring a liquid sample by LIBS, if the sample is still water or a liquid column, the lifetime of the luminous plasma is short and the observed signal becomes unstable. Therefore, the elemental analysis means 20 in this embodiment is equipped with a thin film flow generating unit 210 as a configuration for quickly and sensitively quantifying the concentration of the precious metal element R remaining in the treatment liquid W2.

[0035] The thin film flow generating unit 210 is for carrying out a thin film flow generating step of converting the treatment liquid W2 from which metals have been recovered in the recovery unit 10 into a thin film flow. The thin film flow generating unit 210 may be any unit capable of forming the treatment liquid W2 into a thin film flow, and the thickness of the thin film flow may preferably be 5 μm or more, more preferably 10 μm or more, as a lower limit, and preferably 40 μm or less, more preferably 30 μm or less, as an upper limit. This makes it possible to stably generate long-life luminous plasma on the thin film flow by irradiating laser light from the excitation light irradiating unit 220, which will be described later.

[0036] 2, a specific example of the thin film flow generating unit 210 includes a bypass pipe 211 that sucks up the processing liquid W2 from the line L4 via a bypass pipe lead-in valve 219a, a liquid feed pump 212, a thin film flow generating nozzle 213, and a stage 214 for fixing and adjusting the position of the thin film flow generating nozzle 213. As a result, a part of the processing liquid W2 being transferred in the line L4 is sucked up into the bypass pipe 211 via the liquid feed pump 212, and the processing liquid W2 is sprayed from the thin film flow generating nozzle 213 connected to the bypass pipe 211, thereby making it possible to make the processing liquid W2 into a thin film flow. In addition, the processing liquid W2 sprayed as a thin film flow from the thin film flow generating nozzle 213 is received by a funnel 215 and returned to the line L4 side via a main pipe return valve 219b. 。 At this time, the position where the thin film flow is generated can be adjusted by adjusting the position of the thin film flow generating nozzle 213 via the stage 214. The stage 214 may be any stage that can appropriately move the position of the thin film flow generating nozzle 213 in order to adjust the position where the thin film flow is generated, and examples of the stage 214 include those known as an XY stage, an XYZ stage, or an XYZ / rotation stage.

[0037] As shown in FIG. 2, the thin film flow generating unit 210 is bypass It is preferable to provide a pulsation reducer (pulse damper) 216 and a flow meter 217 on the pipe 211. This makes it easier to continuously eject a stable thin film flow through the thin film flow generating nozzle 213.

[0038] As described above, the thin film flow generating nozzle 213 may have a structure that allows the thickness of the thin film flow generated when the processing liquid W2 is ejected to fall within a predetermined range. For example, the thin film flow generating nozzle 213 may have a structure that utilizes or improves the structure of a nozzle for generating a liquid film in a dye laser (liquid laser). stage 2It is preferable to provide a means for preventing scattering of the processing liquid W2 between the thin film flow generating nozzle 213 directly below 14 and the funnel 215. For example, as shown in Fig. 2, a cylindrical scattering prevention screen 218 may be provided to cover the periphery of the thin film flow. Here, the scattering prevention screen 218 may be made of a material that transmits laser light and light emitted from plasma.

[0039] In this embodiment, the material of the thin film flow generating nozzle 213 is preferably selected according to the properties of the processing liquid W2. In particular, in metal recovery, the solution W1 containing the precious metal element R to be recovered varies depending on the type of metal source M, but is generally an acidic solution containing hydrochloric acid, sulfuric acid, or aqua regia in order to dissolve the precious metal element R in the solution W1, and the liquid property of the treatment solution W2 also tends to be acidic. Therefore, the thin film flow generating nozzle 213 is preferably made of an acid-resistant material, and is particularly preferably one selected from the group consisting of quartz glass, ceramic, and fluororesin. This prevents corrosion and deterioration of the thin film flow generating nozzle 213, allowing for stable and continuous quantitative measurement. In particular, by selecting quartz glass, ceramic, or fluororesin as the acid-resistant material, it is possible to fabricate a thin film flow generating nozzle 213 using a material that is excellent in acid resistance, easy to process, and has sufficient strength, and to continuously form a stable thin film flow. As a result, in-situ analysis and online analysis can be performed more stably.

[0040] The thin film flow of the processing liquid W2 generated by the thin film flow generating unit 210 (hereinafter referred to as "thin film flow T") serves as the sample to be measured in the elemental analysis means 20 of this embodiment.

[0041] The excitation light irradiation unit 220 is for performing an excitation light irradiation step in which the thin film flow T is irradiated with a focused laser beam. The excitation light irradiation section 220 in this embodiment includes an excitation light source 221 and a condenser lens 222 .

[0042] The excitation light source 221 may be any light source capable of emitting laser light, but is preferably a light source capable of emitting pulsed laser light capable of obtaining a large peak output in order to stably generate plasma from the object to be measured (thin film flow T), such as a femtosecond laser, a picosecond laser, or a nanosecond laser. Specific examples of the excitation light source 221 in this embodiment include an Nd:YAG laser, an Nd:glass laser, and a ruby ​​laser. For nanosecond lasers, an oscillator with a pulse width of several tens to several hundreds of nanoseconds is suitable for effective plasma generation.

[0043] The focusing lens 222 is used to irradiate the laser light from the excitation light source 221 in a focused state onto the surface of the thin film flow T, and there is no particular limitation on the type or number of lenses used. In addition, a position adjustment mechanism (not shown) for adjusting the position of the focusing lens 222 may be provided.

[0044] Light-emitting plasma is generated at the irradiated location by irradiating the thin film flow T with laser light from the excitation light irradiation unit 220. At this time, as described above, by providing the scattering prevention screen 218 that transmits the laser light and the light emitted from the plasma, it is possible to prevent a part of the solution (treatment liquid W2) from scattering onto the measuring equipment and the like that constitutes the excitation light irradiation unit 220.

[0045] The spectroscopic detection unit 230 is for carrying out a spectroscopic detection step of separating and detecting light emitted from the generated plasma (plasma light). The spectroscopic detection unit 230 in this embodiment includes a spectrometer introduction means 231 , a spectrometer 232 , and a detector 233 .

[0046] The spectrometer introduction means 231 is for introducing plasma light derived from the light-emitting plasma generated on the thin film flow T into the spectrometer 232, and may be, for example, composed of a lens 231a for focusing the plasma light and an optical fiber 231b.

[0047] The spectroscope 232 is for dispersing the plasma light introduced through the spectroscope introduction means 231, and may be, for example, an Echelle type that can simultaneously observe a wide wavelength range, or a Czerny-Turner type that can sweep wavelengths. This makes it possible to simultaneously measure multiple precious metal elements R, thereby shortening the time required for analysis.

[0048] The detector 233 is for detecting the peak value (spectral intensity) at each wavelength dispersed by the spectrometer 232, and may be, for example, a photomultiplier tube, a CCD camera, a CCD camera with an image intensifier (ICCD) camera, etc. In particular, it is preferable to use an ICCD camera in order to enable quantification with high sensitivity. The spectroscope 232 and the detector 233 may be provided as separate units, or a known spectroscope or photodetector in which the functions of the spectroscope 232 and the detector 233 are integrated may be used.

[0049] Furthermore, it is preferable that the spectroscopic detection unit 230 performs spectroscopic detection of the plasma light after a predetermined time has elapsed since the laser light was irradiated from the excitation light irradiating unit 220. This allows the luminous plasma generated on the thin film flow T to reach a stable thermal equilibrium state, enabling highly sensitive and highly accurate detection of the plasma light from the luminous plasma. Specifically, as shown in FIG. 2, the excitation light source 22 1 and the spectroscopic detection unit 230 (spectroscope 232 and / or detector 233). 1 The reflected light is detected by a photodiode, and the signal is used as a trigger for introducing plasma light to the spectroscopic detection unit 230.

[0050] The detection results (detection wavelength range, spectral intensity) obtained by the spectroscopic detection unit 230 depend on the type and concentration of the precious metal element R in the thin film flow T. Therefore, based on this detection result, it is possible to determine the concentration of the precious metal element R remaining in the treatment liquid W2.

[0051] The noble metal element quantification section 240 is for performing a noble metal element quantification step of calculating the concentration of the noble metal element R remaining in the treatment liquid W2 based on the detection result of the spectroscopic detection section 230. The precious metal element quantification unit 240 in this embodiment may be any unit that receives the detection results of the spectroscopic detection unit 230 and can perform calculations that enable calculation of the concentration (quantification) of the precious metal element R based on these detection results. For example, it may be a computing device equipped with a processor such as a CPU that can execute a program related to data acquisition and calculations required for quantifying the precious metal element R.

[0052] An example of quantification in the precious metal element quantification unit 240 is to first create a calibration curve for each precious metal element R, and then use this calibration curve to calculate (quantify) the concentration of the precious metal element in the processing liquid W2 from the detection results of the spectroscopic detection unit 230 (calibration curve method), or to perform quantification based on the spectral intensity ratio with a standard substance (internal standard method).

[0053] As will be shown in the examples described below, the elemental analysis means 20 of this embodiment is capable of quantifying the precious metal element R in a solution with high sensitivity (detection limit of 1 ppm or less) and over a wide range (wide range). Therefore, even in the case of a solution in which the concentration of the precious metal element R contained fluctuates, such as the treated solution W2 after metal recovery, pretreatment such as dilution or concentration is not required, and in-situ analysis and online analysis are possible, enabling rapid and highly sensitive quantification. This allows for a significant reduction in the processing (analysis) time required for metal recovery, resulting in significant cost savings.

[0054] [Elemental analyzer] The elemental analysis device according to the embodiment of the present invention is capable of performing elemental analysis based on LIBS by measuring an acidic solution containing at least a noble metal element and hydrochloric acid, sulfuric acid, or aqua regia. The elemental analysis device in this embodiment can utilize the configuration of the elemental analysis means 20 in this embodiment described above. More specifically, the elemental analysis device in this embodiment is equipped with at least a thin film flow generating unit 210, an excitation light irradiating unit 220, and a spectroscopic detecting unit 230. In addition, the elemental analysis device in this embodiment can analyze precious metal elements. Preliminary determination The measuring section 240 may be provided separately outside the system, or may be incorporated into the elemental analysis device. In this case, the thin film flow generating nozzle 213 in the thin film flow generating unit 210 is made of the above-mentioned acid-resistant material.

[0055] In general, it is known that in LIBS analysis, the presence of elements other than the element being measured can affect the quantification. On the other hand, the elemental analyzer of this embodiment is designed to measure a liquid sample that is an acidic solution containing at least a precious metal element and hydrochloric acid, sulfuric acid, or aqua regia. By converting the liquid sample into a thin film, pretreatment is not required, and elemental analysis based on LIBS, which enables highly sensitive measurement, is possible. In particular, solutions containing precious metal elements generated during metal recovery processes generally undergo acid dissolution, although this varies depending on the raw materials, and become strongly acidic, containing hydrochloric acid, sulfuric acid, or aqua regia. Therefore, the elemental analyzer of this embodiment is suitable for use as an analyzer for performing elemental analysis on liquid samples containing precious metal elements in metal recovery. Furthermore, as described above, the elemental analyzer of this embodiment does not require pretreatment, so that the device configuration can be easily miniaturized and made portable. Therefore, in addition to continuous monitoring by in-situ analysis or online analysis, it can also be transported to any location where analysis is required.

[0056] Hereinafter, an example will be described relating to the quantitative determination of precious metal elements by the elemental analysis means 20 of this embodiment. This example also corresponds to an example relating to elemental analysis by the elemental analysis apparatus of this embodiment.

[0057] The elements of the elemental analysis means 20 used in the examples are as follows: ·Thin film flow generation section 210 A quartz glass nozzle was used as the thin film flow generating nozzle 213, and a thin film flow T with a thickness of 20 μm was generated. Excitation light irradiation unit 220 An Nd:YAG laser was used as the excitation light source 221, and the laser irradiation conditions were 532 nm, 60 mJ / pulse, and 10 Hz. Spectroscopic detection unit 230 A Czerny-Turner spectrometer was used as the spectrometer 232 , and an ICCD camera was used as the detector 233 .

[0058] For liquid samples containing each precious metal element R, a spectrum from plasma light was obtained using the elemental analysis means 20 configured as described above, and measurement conditions (wavelength (emission line wavelength), delay time by the delay generator 234, etc.) were set to maximize the S / B ratio of the peak intensity of the spectrum obtained for each precious metal element R. Table 1 shows the emission line wavelength among the measurement conditions for each precious metal element R.

[0059] [Table 1]

[0060] Based on the measurement conditions described above, elemental analysis was performed on liquid samples containing each precious metal element R (Au, Ag, Ru, Rh, Pd, Pt). At this time, a calibration curve sample with a known concentration was used for each precious metal element R, and a calibration curve was created from the relationship between the concentration and the peak value of the spectrum at a wavelength (emission line wavelength) specific to the precious metal element R, and the detection limit of each precious metal element R was calculated.

[0061] 3 shows a calibration curve created by the elemental analysis means 20 in this embodiment, and shows the calibration curve when gold (Au) is used as the precious metal element R. The calibration curve shown in FIG. 3 was created using a liquid sample in which gold (Au) was dissolved in a 1 mol / L hydrochloric acid solution, with the horizontal axis representing the concentration [mg / L] and the vertical axis representing the peak value at the emission line wavelength (267.6 nm) [count number (×10 5 ) indicates As shown in Figure 3, the peak value at the emission wavelength (267.6 nm) and the concentration of the precious metal element (Au) show a proportional relationship, and the coefficient of determination (R 2 ) was 0.9995. Furthermore, the calibration curves for other precious metal elements R also showed good coefficients of determination (0.999 or higher). Rh and Pt were dissolved in 1 mol / L hydrochloric acid solution to prepare liquid samples, while Ag, Ru, and Pd were dissolved in 1 mol / L nitric acid solution to prepare liquid samples.

[0062] Here, the detection limit for each precious metal element R is calculated using the obtained calibration curve. The slope of the calibration curve was b, the standard deviation of the blank signal was σ, and the detection limit was calculated as 3σ / b. The calculation results are shown in Table 2 as the detection limit for each precious metal element R.

[0063] [Table 2]

[0064] As shown in Table 2, it was found that the elemental analysis means 20 in this embodiment (or the elemental analysis device in this embodiment) achieved a detection limit of less than 1 ppm for all of the precious metal elements R shown as examples. In other words, it was shown that the metal recovery device 1 and the elemental analysis device in this embodiment can rapidly and sensitively quantify the precious metal elements in a liquid sample containing the precious metal elements without pretreatment.

[0065] The above-described embodiments are examples of the metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method of the present invention. The metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method of the present invention are not limited to the above-described embodiments, and the metal recovery apparatus, metal recovery method, elemental analysis apparatus, and elemental analysis method of the above-described embodiments may be modified within the scope of the gist of the claims.

[0066] For example, the metal recovery device and metal recovery method of this embodiment may be provided with a flow path for circulating the treatment liquid W2 to the recovery section 10 side, and may have a structure or process for repeatedly performing the metal recovery process. More specifically, a branch pipe is provided in the line L4 for transporting the discharged treatment liquid W2, and the tip of the branch pipe is connected to the upstream side of the recovery unit 10 (line L 2 One example is to connect the line L4 to the branch pipe (top), and install a switching valve at the intersection of the line L4 and the branch pipe. The elemental analysis means 20 can quickly determine the concentration of the precious metal element R remaining in the discharged treatment solution W2. If the result of the determination exceeds a set value (threshold), the switching valve can be quickly operated to return (circulate) the treatment solution W2 containing the precious metal element R at or above the predetermined value to the recovery section 10, thereby enabling operations related to improving the recovery rate of the precious metal element to be performed at the appropriate time. Furthermore, since the elemental analysis means 20 can perform in-situ and online analysis, the entire process can easily be automated. This significantly reduces the overall processing time for metal recovery, improving the recovery rate of precious metal elements and significantly reducing costs. [Industrial Applicability]

[0067] The metal recovery device and metal recovery method of the present invention are suitably used in precious metal recycling businesses that recover precious metal elements from solutions containing precious metals. The elemental analysis apparatus and method of the present invention are also suitable for use in quantifying the amount of precious metal elements in a liquid sample containing at least the precious metal elements and hydrochloric acid, sulfuric acid, or aqua regia, and are particularly suitable for use in metal recovery, which involves recovering precious metal elements from a solution, for quantifying the amount of precious metal elements contained in a solution in which the precious metal elements have been dissolved in acid or in a treatment liquid after the precious metal elements have been recovered. [Explanation of symbols]

[0068] 1...metal recovery device, 10...recovery section, 20...elemental analysis means, 210...thin film flow generating section, 211...bypass piping, 212...liquid transfer pump, 213...thin film flow generating nozzle, 214...stage, 215...funnel, 216...pulse damper, 217...flow meter, 218...scattering prevention screen - 219a...bypass piping lead-in valve, 219b...main piping return valve, 220...excitation light irradiation unit, 221...excitation light source, 222...condensing lens, 230...spectrometry detection unit, 231...spectroscope introduction means, 231a...lens, 231b...optical fiber, 232...spectroscope, 233...detector, 234...delay generator, 240...precious metal element quantification unit, 30...receiving unit, 40...evaluation unit, 50...purification unit, L1 to L4...lines, M...metal source, R...precious metal element, T...thin film flow, W1...solution, W2...treatment liquid

Claims

1. A metal recovery apparatus for recovering metals from a solution containing precious metal elements, comprising: a thin film flow generating unit that converts the treated liquid obtained by recovering metals from the solution into a thin film flow; an excitation light irradiation unit that irradiates the thin film flow with a focused laser light; a spectroscopic detection unit that detects light emitted from plasma generated on the thin film flow by the laser light irradiated from the excitation light irradiator through a spectroscopic analysis; A metal recovery device comprising: a precious metal element quantifying unit that calculates the concentration of the precious metal element remaining in the treatment liquid based on the detection result of the spectroscopic detection unit.

2. A metal recovery method for recovering metals from a solution containing precious metal elements, comprising the steps of: a thin film flow generating step of converting the treated liquid obtained by recovering metals from the solution into a thin film flow; an excitation light irradiation step of irradiating the thin film flow with a focused laser light; a spectroscopic detection step of detecting light emitted from plasma generated on the thin film flow by the laser light irradiated in the excitation light irradiation step by spectroscopic analysis; A metal recovery method comprising a precious metal element quantification step of calculating the concentration of the precious metal element remaining in the treatment liquid based on the detection result of the spectroscopic detection step.

3. a thin film flow generating unit for forming a thin film flow from a liquid sample containing a precious metal element; an excitation light irradiation unit that irradiates the thin film flow with a focused laser light; a spectroscopic detection unit that detects light emitted from plasma generated on the thin film flow by the laser light irradiated from the excitation light irradiator, 11. An elemental analyzer according to claim 10, wherein the liquid sample is an acidic solution containing at least hydrochloric acid, sulfuric acid, or aqua regia.

4. 4. The elemental analyzer according to claim 3, wherein the thin film flow generating unit includes a thin film flow generating nozzle made of an acid-resistant material.

5. 5. The elemental analyzer according to claim 4, wherein the acid-resistant material is one selected from the group consisting of quartz glass, ceramics, and fluororesin.

6. 6. The elemental analyzer according to claim 3, wherein the precious metal element is at least one selected from the group consisting of gold, silver, ruthenium, rhodium, palladium, and platinum.

7. a thin film flow generating step of forming a thin film flow from a liquid sample containing a precious metal element; an excitation light irradiation step of irradiating the thin film flow with a focused laser light; a spectroscopic detection step of detecting light emitted from plasma generated on the thin film flow by the laser light irradiated in the excitation light irradiation step, by spectroscopic analysis; 11. The method for elemental analysis, wherein the liquid sample is an acidic solution containing at least hydrochloric acid, sulfuric acid, or aqua regia.

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