CYCLONIC ELECTROLYTIC RECOVERED REDUCED PLATINUM AND WATER ELECTROLYSIS METHOD USING THE SAME

Abstract

Disclosed herein is cyclonic electrolytic recovered reduced platinum obtained by reducing platinum using a cyclone process, manufacturing a water electrolysis catalyst using the reduced platinum, and performing water electrolysis, as well as a water electrolysis method using the same.

Claims

1. A cyclonic electrolytic recovered reduced platinum, wherein a reaction solution containing platinum metal ions is subjected to electrolytic refining and recovered using a cyclone high-speed electrolyzer using high-speed turbulence.

2. The cyclonic electrolytic recovered reduced platinum of claim 1, wherein the cyclone high-speed electrolyzer using high-speed turbulence comprises: an anode in a shape of a rod; and a cathode including a receiving hole for accommodating the anode to form a reaction space between the anode and the cathode, wherein an area ratio of the anode to the cathode in the reaction space is 1 to 100 (Anode/Cathode), wherein a diameter ratio of Do (overflow) to Du (underflow) is 0.001 to 1 (Do/Du), wherein a cross section of the anode is circular, and wherein a cross section of the receiving hole is circular, and the anode is eccentrically positioned in the receiving hole.

3. The cyclonic electrolytic recovered reduced platinum of claim 1, wherein a turbulent flow velocity of the cyclone high-speed electrolyzer using high-speed turbulence is 8 to 10 m/s.

4. The cyclonic electrolytic recovered reduced platinum of claim 1, wherein a helical downward vortex is generated along a wall of the cyclone high-speed electrolyzer using high-speed turbulence for electrolytic recovery of platinum metal to accelerate the electrolyzer at high speed, thereby forming a high-speed turbulent flow, and wherein the high-speed turbulent flow reduces a diffusion layer to significantly improve electrolytic efficiency, thereby remarkably increasing a recovery rate of the platinum metal.

5. The cyclonic electrolytic recovered reduced platinum of claim 2, wherein a maximum distance between the anode and the cathode in the reaction space is 2 to 100 times a minimum distance.

6. The cyclonic electrolytic recovered reduced platinum of claim 2, wherein the cathode is formed with a feed configured to introduce a reactant into the reaction space in a diagonal direction.

7. The cyclonic electrolytic recovered reduced platinum of claim 2, wherein the anode is made of stainless steel, graphite, or platinum, wherein the cathode is made of titanium coated with iridium, and wherein the anode includes a plurality of cylindrical grooves.

8. The cyclonic electrolytic recovered reduced platinum of claim 2, wherein an acid leaching agent is introduced into the reaction space, wherein the acid leaching agent is hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, or organic acid, and wherein a concentration of the acid leaching agent is 0.2 M to 5 M.

9. The cyclonic electrolytic recovered reduced platinum of claim 8, further comprising a process of extracting powder of platinum metal concentrate using the acid leaching agent, wherein a condition for the process of the extracting is characterized by: a leaching time of 0.5 to 12 hours, a pH of 0.5 to 6.5, a solid-to-liquid ratio of 1/2.5 to 1/4, and a temperature of 20 C. to 90 C.

10. The cyclonic electrolytic recovered reduced platinum of claim 2, wherein the reaction solution containing platinum metal ions is introduced into the reaction space for the electrolytic refining, wherein, during the electrolytic refining, an applied voltage is 1.75 V to 25 V, a current is 0.5 to 10 A, and a reaction time is 1 to 720 minutes.

11. The cyclonic electrolytic recovered reduced platinum of claim 10, wherein the platinum metal is leached and recovered simultaneously or separately during a process of electrolytic recovery, and wherein a recovery rate of the platinum metal is 98 to 99.99 wt %.

12. The cyclonic electrolytic recovered reduced platinum of claim 1, wherein a particle size of the cyclonic electrolytic recovered reduced platinum is 0.2 to 100 m.

13. The cyclonic electrolytic recovered reduced platinum of claim 1, wherein, in a result of XPS analysis, the cyclonic electrolytic recovered reduced platinum contains 80 to 93 wt % of platinum and 7 to 20 wt % of ruthenium.

14. A water electrolysis method using cyclonic electrolytic recovered reduced platinum, comprising steps of: (a-1) preparing the cyclonic electrolytic recovered reduced platinum of claim 1 as a water electrolysis catalyst; (a-2) ultrasonically dispersing an electrode solution obtained by mixing the water electrolysis catalyst of the cyclonic electrolytic recovered reduced platinum, an alcohol solvent, and a Nafion solution; (a-3) introducing the ultrasonically dispersed electrode solution into a working electrode of a three-electrode cell and completely drying the working electrode; and (a-4) rotating the dried working electrode while performing an electrochemical reaction in the three-electrode cell to evaluate water electrolysis performance of hydrogen evolution reaction.

15. The water electrolysis method using cyclonic electrolytic recovered reduced platinum of claim 14, wherein, in the step (a-1) of preparing the cyclonic electrolytic recovered reduced platinum as a water electrolysis catalyst, a particle size of the cyclonic electrolytic recovered reduced platinum is 0.2 to 100 m, and wherein, in a result of XPS analysis, the cyclonic electrolytic recovered reduced platinum contains 80 to 93 wt % of platinum and 7 to 20 wt % of ruthenium.

16. The water electrolysis method using cyclonic electrolytic recovered reduced platinum of claim 14, wherein, in the step (a-2) of ultrasonically dispersing an electrode solution obtained by mixing the water electrolysis catalyst of the cyclonic electrolytic recovered reduced platinum, an alcohol solvent, and a Nafion solution, the alcohol solvent is at least one selected from a group consisting of methanol, ethanol, methylcyclohexanol, ethylene glycol, diethylene glycol, isopropanol, propanol, and butanol, and time for ultrasonic dispersion time ranges from 5 minutes to 2 hours.

17. The water electrolysis method using cyclonic electrolytic recovered reduced platinum of claim 14, wherein, in the step (a-3) of introducing the ultrasonically dispersed electrode solution into a working electrode of a three-electrode cell and completely drying the working electrode, the three-electrode cell comprises: a rotating disk electrode (RDE, glassy carbon) as the working electrode; a graphite rod as the counter electrode; and Hg/HgO (1M KOH) as the reference electrode, wherein 1M KOH (25 C.) purged with N.sub.2 is used as electrolyte, and wherein 1 to 3 drops of the ultrasonically dispersed electrode solution are introduced into the working electrode of the three-electrode cell.

18. The water electrolysis method using cyclonic electrolytic recovered reduced platinum of claim 14, wherein, in the step (a-4) of rotating the dried working electrode while performing an electrochemical reaction in the three-electrode cell to evaluate water electrolysis performance of hydrogen evolution reaction, when using the cyclonic electrolytic recovered reduced platinum as a water electrolysis catalyst, in a result of evaluating water electrolysis performance of hydrogen evolution reaction using cyclic voltammetry at a scan rate of 5 mV/s, upon applying a constant current of 10 mA/cm.sup.2, a voltage variation over time remains stable in a range of 18 to 20 mV, exhibiting durability and water electrolysis catalytic activity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG. 1 is a schematic diagram of a cyclone high-speed electrolyzer using high-speed turbulence according to an exemplary embodiment of the present disclosure.

[0064] FIG. 2 is an SEM (Scanning Electron Microscope) image of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0065] FIG. 3 is an XRD (X-ray Diffraction) graph of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0066] FIG. 4 is an XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0067] FIG. 5 is a graph showing the compositional ratio of the XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0068] FIG. 6 is a process flowchart of a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0069] FIG. 7a is a graph showing the electrolytic efficiency at different platinum (Pt) concentrations for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0070] FIG. 7b is a graph showing the electrolytic efficiency at different platinum (Pt) recovery rates for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0071] FIG. 8a is a graph showing the electrolytic efficiency at different platinum (Pt) concentrations as a function of applied voltage for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0072] FIG. 8b is a graph showing the electrolytic efficiency at different platinum (Pt) recovery rates as a function of applied voltage for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0073] FIG. 9 is a graph evaluating the hydrogen evolution reaction (HER) performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0074] FIG. 10 is another graph evaluating the hydrogen evolution reaction (HER) performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0075] FIG. 11 is a graph evaluating the durability performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0076] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to related drawings.

[0077] The advantages and features of the present disclosure, and methods of accomplishing those advantages and features, will become apparent upon reference to the exemplary embodiments described in detail with reference to the accompanying drawings.

[0078] However, the present disclosure is not limited by the exemplary embodiments disclosed herein, but will be embodied in many and various forms. Therefore, those exemplary embodiments are provided merely to make the present disclosure complete and to give a complete picture of the scope of the present disclosure to one of ordinary skill in the art to which the present disclosure belongs, and the present disclosure shall be defined by the scope of the claims.

[0079] Further, hereinafter, in describing the present disclosure, a detailed description of a configuration determined that may unnecessarily obscure the subject matter of the present disclosure, for example, a detailed description of a known technology including the prior art may be omitted.

[0080] Hereinafter, exemplary embodiments of the present disclosure will be described in detail.

Cyclonic Electrolytic Recovered Reduced Platinum

[0081] The present disclosure provides cyclonic electrolytic recovered reduced platinum.

[0082] The present disclosure provides a cyclonic electrolytic recovered reduced platinum, wherein a reaction solution containing platinum metal ions is subjected to electrolytic refining and recovered using a cyclone high-speed electrolyzer using high-speed turbulence.

[0083] According to the present disclosure, there is provided cyclonic electrolytic recovered reduced platinum, obtained by reducing platinum using a cyclone process, which is exhibiting excellent physical properties and enabling versatile applications.

[0084] Generally, high-grade concentrates with a high content of precious metals are obtained from platinum-containing ores mined from mineral deposits using gravity separation and flotation methods. A commonly used smelting technique for processing precious metal-containing concentrates is the cyanidation method using sodium cyanide.

[0085] However, the cyanidation method generates a large amount of pollutants, necessitating the development of an environmentally friendly recovery process.

[0086] Meanwhile, electrolysis is a well-known method for recovering precious metals from leachates, but it has drawbacks such as long processing times and large spatial requirements.

[0087] Therefore, through extensive efforts and research over a long period, the applicant of the present disclosure has obtained cyclonic electrolytic recovered reduced platinum by using a cyclone process for platinum reduction, manufacturing a water electrolysis catalyst from the reduced platinum, and performing water electrolysis using the catalyst. Through these efforts, the present disclosure has been successfully completed.

[0088] The present disclosure provides a cyclonic electrolytic recovered reduced platinum, wherein a reaction solution containing platinum metal ions is subjected to electrolytic refining and recovered using a cyclone high-speed electrolyzer using high-speed turbulence.

[0089] FIG. 1 is a schematic diagram of a cyclone high-speed electrolyzer using high-speed turbulence according to an exemplary embodiment of the present disclosure.

[0090] Referring to FIG. 1, the reactant may be introduced through the Feed into the reaction space, which is the internal space between the Anode at the center of the cyclone high-speed electrolyzer using high-speed turbulence and the Cathode surrounding the Anode.

[0091] Subsequently, by adjusting the diameter (Do) of the Overflow at the upper part of the Anode and the diameter (Du) of the Underflow at the bottom of the cyclone high-speed electrolyzer using high-speed turbulence, strong turbulence is generated, and a voltage is applied to efficiently perform electrolytic refining of the reactant inside the reaction space.

[0092] In addition, referring to the enlarged diagram in FIG. 1, platinum metal ions present in the solution bulk between the Cathode and the wall of the cyclone high-speed electrolyzer using high-speed turbulence are reduced at the Cathode, enabling the recovery of platinum metal.

[0093] Here, the cyclone high-speed electrolyzer using high-speed turbulence may include: an anode in a shape of a rod; and a cathode including a receiving hole for accommodating the anode to form a reaction space between the anode and the cathode.

[0094] In addition, a helical downward vortex may be generated along a wall of the cyclone high-speed electrolyzer using high-speed turbulence for electrolytic recovery of platinum metal to accelerate the electrolyzer at high speed, thereby forming a high-speed turbulent flow. Therefore, the high-speed turbulent flow may reduce a diffusion layer to significantly improve electrolytic efficiency, thereby remarkably increasing a recovery rate of the platinum metal.

[0095] In addition, an area ratio of the anode to the cathode in the reaction space may be 1 to 100 (Anode/Cathode).

[0096] Herein, when the area ratio of the Anode to the Cathode in the reaction space falls within the specified range, the electrolytic efficiency of platinum metal in the cyclone high-speed electrolyzer using high-speed turbulence can be significantly enhanced.

[0097] In this case, the area ratio of the Anode to the Cathode in the reaction space may be preferably 1 to 98 (Anode/Cathode), and more preferably 1 to 95 (Anode/Cathode).

[0098] In addition, a diameter ratio of Do (overflow) to Du (underflow) may be 0.001 to 1 (Do/Du).

[0099] Herein, when the diameter ratio of Do (overflow) to Du (underflow) falls within the specified range, it can induce high-speed turbulence, thereby significantly enhancing the electrolytic efficiency of platinum metal in the cyclone high-speed electrolyzer using high-speed turbulence.

[0100] In this case, the diameter ratio of Do (overflow) to Du (underflow) may be preferably 0.003 to 1 (Do/Du), and more preferably 0.005 to 1 (Do/Du).

[0101] In addition, a cross section of the anode may be circular.

[0102] A cross section of the receiving hole may be circular, and the anode may be eccentrically positioned in the receiving hole.

[0103] In addition, a turbulent flow velocity of the cyclone high-speed electrolyzer using high-speed turbulence may be 8 to 10 m/s.

[0104] Herein, when the turbulent flow velocity of the cyclone high-speed electrolyzer using high-speed turbulence falls within the specified range, the electrolytic efficiency of platinum metal in the electrolyzer can be significantly enhanced.

[0105] In this case, the turbulent flow velocity of the cyclone high-speed electrolyzer using high-speed turbulence may be preferably 8.1 to 10 m/s, and more preferably 8.3 to 10 m/s.

[0106] In addition, a maximum distance between the anode and the cathode in the reaction space may be 2 to 100 times a minimum distance.

[0107] Herein, when the maximum distance between the anode and the cathode in the reaction space falls within the specified range, the electrolytic efficiency of platinum metal in the cyclone high-speed electrolyzer using high-speed turbulence can be significantly enhanced.

[0108] In this case, the maximum distance between the anode and the cathode in the reaction space may be preferably 2 to 98 times the shortest distance, and more preferably 2 to 95 times the shortest distance.

[0109] In addition, an acid leaching agent may be introduced into the reaction space, and the acid leaching agent may be hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, or organic acid. A concentration of the acid leaching agent may be 0.2 M to 5 M. Herein, when the concentration of the acid leaching agent falls within the specified range, a high-concentration platinum metal leaching solution can be obtained.

[0110] In this case, the concentration of the acid leaching agent may be preferably 0.2 M to 4.8 M, and more preferably 0.2 M to 4.5 M.

[0111] In addition, the cathode may be formed with a feed configured to introduce a reactant into the reaction space in a diagonal direction.

[0112] In addition, the anode may be made of stainless steel, graphite, or platinum, the cathode may be made of titanium coated with iridium, and the anode may include a plurality of cylindrical grooves.

[0113] Moreover, there may be provided a process of extracting powder of platinum metal concentrate using the acid leaching agent, and a condition for the process of the extracting may be characterized by:

[0114] a leaching time of 0.5 to 12 hours,

[0115] a pH of 0.5 to 6.5,

[0116] a solid-to-liquid ratio of 1/2.5 to 1/4, and

[0117] a temperature of 20 C. to 90 C.

[0118] Herein, when the leaching time falls within the specified range, the platinum metal concentrate powder can be extracted at a high concentration.

[0119] In this case, the leaching time is preferably 0.5 hours to 11.5 hours, and more preferably 0.5 hours to 11 hours.

[0120] In addition, when the pH falls within the specified range, the platinum metal concentrate powder can be extracted at a high concentration.

[0121] In this case, the pH may be preferably 0.5 to 6.4, and more preferably 0.5 to 6.3.

[0122] Furthermore, when the solid-to-liquid ratio (S/L ratio) falls within the specified range, the platinum metal concentrate powder can be extracted at a high concentration.

[0123] In this case, the solid-to-liquid ratio may be preferably 1/2.5 to 1/3.9, and more preferably 1/2.5 to 1/3.8.

[0124] In addition, when the temperature falls within the specified range, the platinum metal concentrate powder can be extracted at a high concentration.

[0125] In this case, the temperature may be preferably 20 C. to 88 C., and more preferably 20 C. to 85 C.

[0126] In addition, the reaction solution containing platinum metal ions may be introduced into the reaction space for the electrolytic refining. During the electrolytic refining, an applied voltage may be 1.75 V to 25 V, a current may be 0.5 to 10 A, and a reaction time may be 1 to 720 minutes.

[0127] Here, when the applied voltage falls within the specified range, the platinum metal can be recovered with high efficiency.

[0128] In this case, the applied voltage may be preferably 1.75 V to 24 V, and more preferably 1.75 V to 23 V.

[0129] In addition, when the current falls within the specified range, the platinum metal can be recovered with high efficiency.

[0130] In this case, the current may be preferably 0.5 to 9.9 A, and more preferably 0.5 to 9.8 A.

[0131] Furthermore, when the reaction time falls within the specified range, the platinum metal can be recovered with high efficiency.

[0132] In this case, the reaction time may be preferably 1 to 710 minutes, and more preferably 1 to 700 minutes.

[0133] In addition, the platinum metal may be leached and recovered simultaneously or separately during the process of electrolytic recovery, and a recovery rate of the platinum metal may be 98 to 99.99 wt %.

[0134] In addition, a particle size of the cyclonic electrolytic recovered reduced platinum may be 0.2 to 100 m.

[0135] Here, the particle size of the cyclonic electrolytic recovered reduced platinum may be preferably 0.5 to 100 m, and more preferably 1.0 to 100 m.

[0136] FIG. 2 is an SEM (Scanning Electron Microscope) image of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0137] Referring to FIG. 2, the particle size of the cyclonic electrolytic recovered reduced platinum may range from 0.2 to 100 m.

[0138] FIG. 3 is an XRD (X-ray Diffraction) graph of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0139] Referring to FIG. 3, the XRD graph of the cyclonic electrolytic recovered reduced platinum is identical to the standard XRD graph of platinum.

[0140] In addition, in a result of XPS analysis of the cyclonic electrolytic recovered reduced platinum, 80 to 93 wt % of platinum and 7 to 20 wt % of ruthenium may be contained.

[0141] FIG. 4 is an XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0142] FIG. 5 is a graph showing the compositional ratio of the XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0143] Referring to FIGS. 4 and 5, the XPS analysis results of the cyclonic electrolytic recovered reduced platinum indicate that the composition and content may comprise 80 to 93 wt % platinum and 7 to 20 wt % ruthenium.

Water Electrolysis Method Using Cyclonic Electrolytic Recovered Reduced Platinum

[0144] The present disclosure provides a water electrolysis method using cyclonic electrolytic recovered reduced platinum, wherein platinum is reduced using a cyclone process, and the reduced platinum is used to manufacture a water electrolysis catalyst for performing water electrolysis.

[0145] According to the present disclosure, there is provided a water electrolysis method using cyclonic electrolytic recovered reduced platinum, comprising steps of: [0146] (a-1) preparing the cyclonic electrolytic recovered reduced platinum of any one of claims 1 to 13 as a water electrolysis catalyst; [0147] (a-2) ultrasonically dispersing an electrode solution obtained by mixing the water electrolysis catalyst of the cyclonic electrolytic recovered reduced platinum, an alcohol solvent, and a Nafion solution; [0148] (a-3) introducing the ultrasonically dispersed electrode solution into a working electrode of a three-electrode cell and completely drying the working electrode; and [0149] (a-4) rotating the dried working electrode while performing an electrochemical reaction in the three-electrode cell to evaluate water electrolysis performance of hydrogen evolution reaction.

[0150] The present disclosure provides a water electrolysis method using cyclonic electrolytic recovered reduced platinum, in which platinum is reduced using a cyclonic process, and the reduced platinum is used to manufacture a water electrolysis catalyst for water electrolysis. This method offers excellent process stability, enables mass production, and is cost-effective.

[0151] Herein, in the step (a-1) of preparing the cyclonic electrolytic recovered reduced platinum as a water electrolysis catalyst, a particle size of the cyclonic electrolytic recovered reduced platinum may be 0.2 to 100 m.

[0152] In addition, in a result of XPS analysis, the cyclonic electrolytic recovered reduced platinum may contain 80 to 93 wt % of platinum and 7 to 20 wt % of ruthenium.

[0153] FIG. 2 is an SEM (Scanning Electron Microscope) image of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure. Referring to FIG. 2 again, the particle size of the cyclonic electrolytic recovered reduced platinum may range from 0.2 to 100 m.

[0154] Here, a particle size of the cyclonic electrolytic recovered reduced platinum may be 0.2 to 100 m.

[0155] Further, the particle size of the cyclonic electrolytic recovered reduced platinum may be preferably 0.5 to 100 m, and more preferably 1.0 to 100 m.

[0156] FIG. 3 is an XRD (X-ray Diffraction) graph of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0157] Referring to FIG. 3 again, the XRD graph of the cyclonic electrolytic recovered reduced platinum is identical to the standard XRD graph of platinum.

[0158] In addition, in a result of XPS analysis of the cyclonic electrolytic recovered reduced platinum, 80 to 93 wt % of platinum and 7 to 20 wt % of ruthenium may be contained.

[0159] FIG. 4 is an XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0160] FIG. 5 is a graph showing the compositional ratio of the XPS (X-ray Photoelectron Spectroscopy) spectrum of cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0161] Referring to FIGS. 4 and 5, the XPS analysis results of the cyclonic electrolytic recovered reduced platinum indicate that the composition and content may comprise 80 to 93 wt % platinum and 7 to 20 wt % ruthenium.

[0162] In addition, in the step (a-2) of ultrasonically dispersing an electrode solution obtained by mixing the water electrolysis catalyst of the cyclonic electrolytic recovered reduced platinum, an alcohol solvent, and a Nafion solution,

[0163] the alcohol solvent may be at least one selected from a group consisting of methanol, ethanol, methylcyclohexanol, ethylene glycol, diethylene glycol, isopropanol, propanol, and butanol, and

[0164] time for ultrasonic dispersion time may range from 5 minutes to 2 hours.

[0165] Here, when the alcohol solvent is used, the water electrolysis catalyst efficiency of the cyclonic electrolytic recovered reduced platinum may be significantly improved.

[0166] In addition, when the ultrasonic dispersion time is within the specified range, the ultrasonic dispersion of the electrode solution, which is a mixture of the cyclonic electrolytic recovered reduced platinum water electrolysis catalyst, alcohol solvent, and Nafion solution, may be excellent.

[0167] In this case, the ultrasonic dispersion time may preferably range from 5 minutes to 1 hour and 50 minutes, and more preferably from 5 minutes to 1 hour and 30 minutes.

[0168] In addition, in the step (a-3) of introducing the ultrasonically dispersed electrode solution into a working electrode of a three-electrode cell and completely drying the working electrode, the three-electrode cell comprises:

[0169] a rotating disk electrode (RDE, glassy carbon) as the working electrode;

[0170] a graphite rod as the counter electrode; and

[0171] Hg/HgO (1M KOH) as the reference electrode.

[0172] Here, 1M KOH (25 C.) purged with N.sub.2 may be used as electrolyte, and

[0173] 1 to 3 drops of the ultrasonically dispersed electrode solution may be introduced into the working electrode of the three-electrode cell.

[0174] Furthermore, in the step (a-4) of rotating the dried working electrode while performing an electrochemical reaction in the three-electrode cell to evaluate water electrolysis performance of hydrogen evolution reaction,

[0175] when using the cyclonic electrolytic recovered reduced platinum as a water electrolysis catalyst,

[0176] in a result of evaluating water electrolysis performance of hydrogen evolution reaction using cyclic voltammetry at a scan rate of 5 mV/s,

[0177] upon applying a constant current of 10 mA/cm.sup.2, a voltage variation over time may remain stable in a range of 18 to 20 mV, exhibiting durability and water electrolysis catalytic activity.

[0178] Here, from the fact that the voltage variation remains constant, it can be confirmed that, when the cyclonic electrolytic recovered reduced platinum is used as a water electrolysis catalyst, it exhibits excellent durability and outstanding water electrolysis catalytic activity.

[0179] FIG. 6 is a process flowchart of a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0180] Referring to FIG. 6, at first, the cyclonic electrolytic recovered reduced platinum may be prepared as a water electrolysis catalyst (S110).

[0181] Then, an electrode solution may be prepared by ultrasonically dispersing a mixture of the water electrolysis catalyst, an alcohol solvent, and a Nafion solution (S120).

[0182] Next, the ultrasonically dispersed electrode solution may be applied to the working electrode of a three-electrode cell and completely dried (S130).

[0183] Finally, while rotating the dried working electrode, an electrochemical reaction may be conducted in the three-electrode cell, such that the water electrolysis performance for the hydrogen evolution reaction can be evaluated (S140).

[0184] Hereinafter, the present disclosure will be described in more detail through exemplary embodiments. However, the following exemplary embodiments are provided to further illustrate the present disclosure, and the scope of the present disclosure is not limited to these exemplary embodiments. The following exemplary embodiments may be appropriately modified or altered by those skilled in the art within the scope of the present disclosure.

Exemplary Embodiments

<Exemplary Embodiments 1 to 3> High-Speed Turbulent Cyclone Electrolytic Refining Using Hydrochloric Acid Leaching Agent

[0185] A platinum metal leaching solution with an initial concentration of 50 to 100 ppm of platinum metal ions, obtained using a hydrochloric acid leaching agent, was introduced into the reaction space of the cyclone high-speed electrolyzer using high-speed turbulence specified in Table 1 below. Electrolytic refining was then performed under the conditions listed in Table 1 below.

<Exemplary Embodiments 4 to 6> High-Speed Turbulent Cyclone Electrolytic Refining Using Sulfuric Acid Leaching Agent

[0186] A platinum metal leaching solution with an initial concentration of 50 to 100 ppm of platinum metal ions, obtained using a sulfuric acid leaching agent, was introduced into the reaction space of the cyclone high-speed electrolyzer using high-speed turbulence specified in Table 1 below. Electrolytic refining was then performed under the conditions listed in Table 1 below.

TABLE-US-00001 TABLE 1 Ex- Ex- Ex- Ex- Ex- Ex- emplary emplary emplary emplary emplary emplary em- em- em- em- em- em- bodiment 1 bodiment 2 bodiment 3 bodiment 4 bodiment 5 bodiment 6 Anode/Cathode 1 1.02 1.5 1 1.02 1.5 Area Ratio Do/Du 0.5 0.7 1.0 0.5 0.7 1.0 Diameter Ratio Anode Type Stainless Graphite Platinum Stainless Graphite Platinum Steel Steel Cathode Type Titanium Titanium Titanium Titanium Titanium Titanium Acid Leaching Hydrochloric Hydrochloric Hydrochloric Sulfuric Sulfuric Sulfuric Agent Acid Acid Acid Acid Acid Acid Acid Leaching 0.2 2 5 0.2 2 5 Agent Concentration (M) Leaching Time 12 8 0.5 12 8 0.5 (hr) pH 6.5 2 0.5 6 1 0.3 Solid-to- 1/2.5 1/3 1/4 1/2.5 1/3 1/4 Liquid Ratio Temperature 90 40 20 20 90 40 ( C.) Applied 1.75 7.5 25 25 10 1.75 Voltage (V) Current (A) 0.5 3.9 10 5 10 0.5 Reaction time 10 480 720 1 480 240 (min) Platinum 98 >99.84 99.99 99 99.5 99.9 Metal Recovery Rate (wt %)

[0187] Referring to Table 1, the platinum metal recovery rate in Exemplary embodiments 1 to 3 ranged from 98 to 99.99 wt %, while the platinum metal recovery rate in Exemplary embodiments 4 to 6 ranged from 99 to 99.9 wt %.

<Exemplary Embodiment 7> Water Electrolysis of Reduced Platinum Metal for Hydrogen Evolution Reaction

[0188] The reduced platinum metal recovered from the high-speed turbulent cyclone electrolytic refining process using sulfuric acid leaching in Exemplary embodiment 4 was prepared as a water electrolysis catalyst.

[0189] Subsequently, an electrode solution was prepared by mixing 20 mg of the cyclonic electrolytic recovered reduced platinum as a water electrolysis catalyst, 900 L of ethanol, and 100 L of Nafion solution, followed by ultrasonic dispersion for 15 minutes.

[0190] Next, 5 L of the ultrasonically dispersed electrode solution was dropped once onto the working electrode of a three-electrode cell and completely dried.

[0191] Here, the three-electrode cell includes:

[0192] a rotating disk electrode (RDE) made of glassy carbon as the working electrode,

[0193] a graphite rod as the counter electrode, and

[0194] a Hg/HgO (1M KOH) electrode as the reference electrode.

[0195] In addition, nitrogen-purged 1M KOH (25 C.) was used as the electrolyte.

[0196] Afterward, the dried working electrode (RDE) was rotated at 1600 rpm while performing an electrochemical reaction in the three-electrode cell to evaluate the water electrolysis performance of the hydrogen evolution reaction (HER).

<Exemplary Embodiment 8> Water Electrolysis of a Composite of Reduced Platinum Metal and Carbon for Hydrogen Evolution Reaction

[0197] Water electrolysis was performed and evaluated using the same method as in Exemplary embodiment 7, except that a composite of carbon and reduced platinum metal recovered from the high-speed turbulent cyclone electrolytic refining process using sulfuric acid leaching in Exemplary embodiment 4 was used as the water electrolysis catalyst. The reduced platinum metal and carbon composite from Exemplary embodiment 8 was designated as recycled PtRu (XPS analysis result: Pt:Ru=87 wt %:13%).

<Comparative Example> Commercial Pt/C Catalyst

[0198] A commercial Pt/C catalyst (Pt:Carbon=40 wt %:60 wt %) was prepared.

Experimental Examples

<Experimental Example 1> Measurement of Electrolytic Recovery Efficiency of Platinum Precious Metal at Different Concentrations in High-Speed Turbulent Cyclone Electrolytic Refining Behavior

[0199] The electrolytic recovery efficiency of platinum (Pt) precious metal at different concentrations in the high-speed turbulent cyclone electrolytic refining behavior using hydrochloric acid leaching, as described in Exemplary embodiment 2, is shown in FIG. 7.

[0200] FIG. 7a is a graph showing the electrolytic efficiency at different platinum (Pt) concentrations for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0201] FIG. 7b is a graph showing the electrolytic efficiency at different platinum (Pt) recovery rates for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0202] Referring to FIG. 7a, at low concentrations, residual ions remained close to 0 ppm after 1 hour of reaction time, while at high concentrations, residual ions remained close to 0 ppm after 2 hours of reaction time.

[0203] In addition, referring to FIG. 7b, at low concentrations, platinum (Pt) was electrolytically recovered at nearly 100 wt % within 1 hour of reaction time, while at high concentrations, platinum (Pt) was electrolytically recovered at nearly 100 wt % within 2 hours of reaction time.

<Experimental Example 2> Measurement of Electrolytic Recovery Efficiency of Platinum Precious Metal Depending on Applied Voltages in High-Speed Turbulent Cyclone Electrolytic Refining Behavior

[0204] The electrolytic recovery efficiency of platinum (Pt) precious metal depending on different applied voltages in the high-speed turbulent cyclone electrolytic refining behavior using hydrochloric acid leaching, as described in Exemplary embodiment 2, is shown in FIG. 8.

[0205] FIG. 8a is a graph showing the electrolytic efficiency at different platinum (Pt) concentrations as a function of applied voltage for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0206] FIG. 8b is a graph showing the electrolytic efficiency at different platinum (Pt) recovery rates as a function of applied voltage for cyclonic electrolytic recovery after chlorine leaching according to an exemplary embodiment of the present disclosure.

[0207] Referring to FIG. 8a, at the applied voltage, residual ions remained close to 0 ppm after 1 hour of reaction time.

[0208] In addition, referring to FIG. 8b, platinum (Pt) was electrolytically recovered at nearly 100 wt % within 1 hour of reaction time.

<Evaluation example> Evaluation of Hydrogen Evolution Reaction (Her) Performance and Durability of water Electrolysis

[0209] The hydrogen evolution reaction (HER) performance of water electrolysis using the reduced platinum metal and carbon composite from Exemplary embodiment 8 was evaluated through cyclic voltammetry at a scan rate of 5 mV/s.

[0210] In addition, the durability of water electrolysis in Exemplary embodiment 8 was evaluated by analyzing voltage changes over time while applying a constant current of 10 mA/cm.sup.2.

[0211] FIG. 9 is a graph evaluating the hydrogen evolution reaction (HER) performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0212] FIG. 10 is another graph evaluating the hydrogen evolution reaction (HER) performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0213] FIG. 11 is a graph evaluating the durability performance in a water electrolysis method using cyclonic electrolytic recovered reduced platinum according to an exemplary embodiment of the present disclosure.

[0214] Referring to FIGS. 9 to 11, the hydrogen evolution reaction (HER) performance of water electrolysis was evaluated through cyclic voltammetry at a scan rate of 5 mV/s.

[0215] As a result, when analyzing voltage changes over time while applying a constant current of 10 mA/cm.sup.2, it was confirmed that voltage variation remained stable at 20 mV, indicating excellent durability and catalytic activity.

[0216] In particular, referring to FIGS. 9 and 10, for comparison, a commercial Pt/C catalyst (Pt:Carbon=40 wt %:60 wt %) was used as a comparative example.

[0217] The recycled PtRu catalyst from Exemplary embodiment 8 (XPS analysis: Pt:Ru=87 wt %:13 wt %) was evaluated for hydrogen evolution reaction characteristics.

[0218] Here, for a direct comparison with the commercial product of the comparative example, the recycled PtRu/Carbon (PtRu:Carbon=40 wt %:60 wt %) from Exemplary embodiment 8 was used for evaluation.

[0219] As a result, the recycled PtRu catalyst from Exemplary embodiment 8 (20 mV at 10 mA/cm.sup.2) exhibited superior catalytic activity compared to the commercial Pt/C catalyst (23 mV at 10 mA/cm.sup.2).

[0220] Furthermore, the recycled PtRu catalyst from Exemplary embodiment 8 demonstrated superior kinetics, as evidenced by a lower Tafel slope compared to the commercial Pt/C catalyst.

[0221] In addition, referring to FIG. 11, the durability of the recycled PtRu/Carbon (PtRu:Carbon=40 wt %:60 wt %) from Exemplary embodiment 8 was evaluated by applying a current density of 10 mA/cm.sup.2 and monitoring voltage changes over time. The evaluation results showed that voltage remained stable over 15 hours, confirming its excellent durability.

[0222] In the above, exemplary embodiments of a cyclone high-speed electrolyzer using high-speed turbulence, a method for recovering valuable metals using the same, and the valuable metals recovered therefrom according to the present disclosure have been described. Moreover, it will be appreciated that various modifications to these exemplary embodiments are possible without departing from the scope of the present disclosure.

[0223] The scope of the present disclosure should therefore not be limited to those exemplary embodiments described above, but should be defined by the following claims and their equivalents.

[0224] In other words, the foregoing exemplary embodiments are to be understood as illustrative rather than restrictive in all respects, and the scope of the present disclosure is indicated by the following claims rather than the detailed description. All modifications or variations derived from the meaning, scope, and equivalent concepts of the claims should be interpreted as being included within the scope of the present disclosure.