A method for selectively separating reduced noble metals using gel electrophoresis

Abstract

The present application belongs to the technical field of noble metal separation and recovery, and particularly relates to a method for selectively separating reduced noble metals by gel electrophoresis, comprising the following steps: adding agarose powder into a sodium citrate solution, and ultrasonically stirring to obtain a uniformly dispersed mixed solution; heating the mixed solution and then cooling it, pouring the cooled mixed solution into a gel plate, and solidifying to obtain a sodium citrate-agarose gel; separating noble metal ions by gel electrophoresis, and reducing the ionic noble metals loaded on the sodium citrate-agarose gel to obtain two kinds of noble metals, namely gold and palladium. During the reaction, two relatively obvious bands appear in the sodium citrate-agarose gel, first, the palladium ions migrate from the negative electrode and show yellow color at a specific position; then the gold ions migrate and show purple color at a specific position, finally achieving the purpose of separating and reducing gold and palladium. The whole system reaction is mild, and no toxic substances are produced, and can be used for noble metal separation and recovery and other applications.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of noble metal separation and recovery, and particularly relates to a method for selectively separating reduced noble metals by gel electrophoresis. BACKGROUND

[0002] Noble metals (PMs) mainly refer to gold, silver and eight metal elements such as platinum group metals (ruthenium, rhodium, palladium, osmium, iridium and platinum). As a very important noble metal resource, in recent years, it has been widely used in catalysis, aerospace, medical industry and communication and other high-tech fields, and is known as the "vitamin" of modern industry and "modern new metal". However, due to the scarcity of gold resources and the fact that the existing mining infrastructure will be difficult to meet the demand, society urgently needs sustainable development technology to realize the selective separation and recovery of gold resources. At present, the ore grade is continuously reduced, and the noble metal content in typical waste electrical and electronic equipment (WEEE), scrap industrial or automobile catalysts, fuel cells and storage batteries is much higher than that in ores and minerals.

[0003] At present, the technologies for selectively separating and reducing noble metals in waste liquid include selective precipitation separation method and solvent extraction separation method. Due to its wide application and bottleneck, the process flow and processing period of the selective precipitation separation method are long, the selectivity of separation is not high, the reagent consumption is large, and the direct recovery rate of noble metals is not high; and although the solvent extraction separation method has metal selectivity, simplifies the process, shortens the period, improves the direct recovery rate and the safety of production operation, it has low recovery efficiency and is not environmentally friendly. Scientists have also proposed an electrochemical method, which has attracted widespread attention due to its environmental protection and high recovery rate, and does not require additional reagents. However, it is energy-consuming, expensive and produces certain by-products.

[0004] In summary, the current method for selectively separating and reducing noble metals in waste liquid cannot selectively separate multiple noble metals, which will cause waste of noble metals to some extent. SUMMARY

[0005] The purpose of the present application is to provide a method for selectively separating and reducing noble metals by gel electrophoresis, which solves the problem of being unable to selectively separate multiple noble metals, which will cause waste of noble metals to some extent.

[0006] The present application is realized by the following technical solutions:

[0007] The present application discloses a method for selectively separating and reducing noble metals by gel electrophoresis, comprising the following steps:

[0008] (1) adding agarose powder into a sodium citrate solution and ultrasonically stirring to obtain a uniformly dispersed mixed solution;

[0009] (2) after heating the mixed solution, cooling the mixed solution, pouring the cooled mixed solution into a gel plate, and solidifying to obtain the sodium citrate-agarose gel;

[0010] (3) separating the noble metal ions by using the gel electrophoresis method, and reducing the ionic noble metals loaded on the sodium citrate-agarose gel to obtain gold and palladium and other noble metals.

[0011] Further, in step (1), the preparation process of the sodium citrate solution is as follows:

[0012] The sodium citrate solid is added into the deionized water, and stirring is performed to obtain the uniformly dispersed sodium citrate solution.

[0013] Further, the mass ratio of the sodium citrate to the agarose is (0.25-1.5):(1-5).

[0014] Further, in step (1), the concentration of the agarose in the mixed solution is 1%-5%.

[0015] Further, in step (1), the ultrasonic stirring time is 5-10 min.

[0016] Further, in step (2), the heating temperature is 90-120℃, and the heating time is 3-5 min.

[0017] Further, in step (2), after the mixed solution is poured into the gel plate, it becomes a semi-solid state at 35-40℃, and then becomes a gel state, and thus the sodium citrate-agarose gel is obtained.

[0018] Further, in step (3), the parameters of the gel electrophoresis method are as follows: the voltage is 40-100 V, and the current is 40-100 mA.

[0019] Further, in step (3), the electrophoresis liquid of the gel electrophoresis method is a sodium chloride solution.

[0020] Compared with the prior art, the present application has the following beneficial technical effects:

[0021] The application discloses a method for selectively separating and reducing noble metals by gel electrophoresis, and uses cheap sodium citrate and agarose gel as raw materials to provide a high-efficiency and energy-saving method for selectively separating and recovering gold and palladium. The method realizes efficient and green separation of gold and palladium through reduction and complexation. Sodium citrate is added because of the special structure of the active methylene group and the hydroxyl functional group, and the noble metal ions are coordinated to form stable complexes in the reaction process. Agarose is added because it is an organic substance that maintains a network structure through hydrogen bonds. Moreover, the agarose gel has the dual functions of "molecular sieve" and "electrophoresis" under the condition of electrophoresis. In addition, the agarose gel has a network structure, high adsorption and reduction capacity. In addition, the whole experimental process does not involve toxic gases, and has broad development prospects.

[0022] The application uses the differences in the size radius, shape and charge amount of various noble metal ions under an electric field, uses the gel electrophoresis technology to separate the noble metal ions and reduce the noble metal ions loaded on the gel, and provides a new idea and method for separating and reducing noble metals, and realizes the cross of disciplines.

[0023] The application uses the gel electrophoresis technology to selectively separate and reduce gold and palladium from a solution containing noble metals. The system has good selectivity in the reaction process, is non-toxic, friendly to the environment and the like, and is suitable for separating and reducing noble metal ions with a low concentration (within 50 ppm). The system has a short separation time, can realize rapid reduction of gold and palladium, and the separation rates of the separated gold and palladium particles reach 92.22% and 90.53% respectively. In the solution containing noble metals, the noble metals are distinguished by their different properties, migrate in the gel at different migration rates, the ions with the fastest migration speed are arranged in the front, other ions are arranged in order of speed, and are colored and reduced at different positions. In the reaction process, two relatively obvious bands appear in the sodium citrate-agarose gel, first, the palladium ions migrate from the negative electrode and show yellow color at a specific position; then the gold ions migrate and show purple color at a specific position, and finally the purpose of separating and reducing gold and palladium is realized. The whole system reaction is mild, does not produce toxic substances, and can be used for noble metal separation and recovery and the like.

[0024] Further, the traditional TAE solution is an alkaline solution, which can change the acidity and alkalinity of the solution under the action of the current; the electrophoresis liquid of the gel electrophoresis method is a sodium chloride solution, which is a neutral solution and does not change the acidity and alkalinity of the solution, can stably maintain the pH of the solution, and provides the movement of anions and cations and maintains the acidity and alkalinity of the solution under the condition of power supply. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 XRD patterns of agarose, sodium citrate, sodium citrate-agarose of Example 1;

[0026] Figure 2 XRD pattern of sodium citrate-agarose loaded with gold particles of Example 1;

[0027] Figure 3 XRD pattern of sodium citrate-agarose loaded with palladium particles of Example 1;

[0028] Figure 4 XPS pattern of sodium citrate-agarose loaded with gold particles of Example 1;

[0029] Figure 5 XPS pattern of sodium citrate-agarose loaded with palladium particles of Example 1;

[0030] Figure 6 Effect of different contents of reducing agent sodium citrate on the separation rate of noble metal particles in the mixed solution in the present application;

[0031] Figure 6 Effect of different contents of reducing agent sodium citrate on the separation rate of noble metal particles in the mixed solution in the present application on the yellow gel band;

[0032] Figure 6 Effect of different contents of reducing agent sodium citrate on the separation rate of noble metal particles in the mixed solution in the present application on the purple gel band;

[0033] Figure 7 Effect of different concentrations of agarose gel in the present application on the separation rate of noble metal particles in the mixed solution;

[0034] Figure 7 Effect of different concentrations of agarose gel on the separation rate of noble metal particles in the mixed solution on the yellow gel band;

[0035] Figure 7 Effect of different concentrations of agarose gel on the separation rate of noble metal particles in the mixed solution on the purple gel band. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made in combination with the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application, i.e., the described examples are only a part of the examples of the present application, but not all the examples.

[0037] The components described and illustrated in the figures and embodiments of the present application can be arranged and designed in a wide variety of different configurations, therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the application, but merely represents one selected embodiment of the present application. Based on the figures and embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work, fall within the scope of the present application.

[0038] It should be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that the process, element, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or inherent to the process, element, method, article or equipment.

[0039] The features and performances of the present application are further described in detail below in combination with embodiments.

[0040] The present application discloses a method for selectively separating and reducing noble metals by gel electrophoresis, comprising the following steps:

[0041] 1) adding sodium citrate solid into deionized water, and stirring to obtain a uniformly dispersed sodium citrate solution;

[0042] adding agarose powder into the above sodium citrate solution, and ultrasonically stirring to obtain a uniformly dispersed mixed solution;

[0043] 2) heating and dissolving the mixed solution to obtain a sodium citrate-agarose mixed solution;

[0044] pouring the slightly cooled sodium citrate-agarose mixed solution after heating into a gel plate, and solidifying to obtain a sodium citrate-agarose gel.

[0045] 3) separating noble metal ions by gel electrophoresis, and reducing the ionic noble metals loaded on the sodium citrate-agarose gel, mainly obtaining two kinds of noble metals of gold and palladium.

[0046] The electrophoresis solution used in the gel electrophoresis of the present application is a 0.04M sodium chloride solution, which provides the movement of anions and cations under the condition of electricity and maintains the acid-base property of the solution.

[0047] Example 1

[0048] The present application discloses a method for selectively separating and reducing noble metals by gel electrophoresis, comprising the following steps:

[0049] (1) adding 0.5g sodium citrate solid into 100mL deionized water, and stirring to obtain a uniformly dispersed sodium citrate solution;

[0050] (2) 3g of agarose powder was added into the above sodium citrate solution, and a uniformly dispersed mixed solution was obtained by ultrasonic stirring for 5 min;

[0051] (3) The mixed solution was heated in a microwave oven at 90°C for 3 min;

[0052] The heated mixed solution B was then poured into a gel plate after being slightly cooled, and a sodium citrate-agarose gel was obtained by solidification for 30 min.

[0053] (4) The noble metal ions were separated by gel electrophoresis, and the ion state noble metals loaded on the sodium citrate-agarose gel were reduced to obtain two kinds of noble metals of gold and palladium. The details are as follows:

[0054] The simulated actual leaching solution [Au(III), Pd(II), Pt(II), Cu(II), Ni(II)] was dropped into the gel hole for experiment by using a gel electrophoresis device under the control of a voltage of 60 V and a current of 60 mA, and the reaction time was 30 min. Finally, the color development gel strip of a specified distance was taken for digestion, and the content of noble metals in different color development gel strips was quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0055] Referring to Figure 1 , Figure 1 XRD patterns of agarose, sodium citrate, and sodium citrate-agarose, which can be seen from Figure 1 that there is a diffraction peak near 19.3° in the agarose powder, which is the characteristic peak of agarose. In the AG-SC, in addition to the characteristic peak of agarose, there is a diffraction peak near 13.5°, which is the characteristic peak of sodium citrate, indicating that the loading of sodium citrate is successful. After loading sodium citrate, the characteristic peak does not shift obviously, which proves that the loading of sodium citrate does not change the structure of agarose.

[0056] Referring to Figure 2 , Figure 2 XRD pattern of sodium citrate-agarose loaded with gold particles, which can be seen from Figure 2 that there are sharp peak values near 38.24°, 44.39°, and 64.58°, which are compared with the standard card of gold, and it is found that they all correspond to the typical values of elemental gold, which indicates that Au(III) is reduced to gold nanoparticles under the conditions of electrophoresis.

[0057] Referring to Figure 3 , Figure 3 XRD pattern of sodium citrate-agarose loaded with palladium particles, which can be seen from Figure 3It can be seen that there are sharp peaks near 39.9°, 46.4° and 67.7°, which are compared with the standard card of palladium, and it is found that they all correspond to the typical values of elemental palladium, so it is proved that Pd(II) is reduced to palladium nanoparticles under the condition of electrophoresis.

[0058] Referring to Figure 4 , Figure 4 The XPS diagram of sodium citrate-agarose loaded with gold particles is shown in the following figure: Figure 4 It can be seen that a new peak indexed by Au appears on the spectrum of AG-Au, which proves that the loading of gold ions by AG gel is successful.

[0059] Referring to Figure 5 , Figure 5 The XPS diagram of sodium citrate-agarose loaded with palladium particles is shown in the following figure: Figure 5 It can be seen that a new peak indexed by Pd appears on the spectrum of AG-Pd, which proves that the loading of palladium ions by AG gel is successful.

[0060] The method is simple in operation and environmentally friendly in process, and the separation rates of the separated and reduced gold and palladium particles are 92.22% and 90.53% respectively, which also provides a new idea for the separation of noble metals.

[0061] Example 2

[0062] The application discloses a method for selectively separating and reducing noble metals by gel electrophoresis, which comprises the following steps:

[0063] (1) 0.25g of sodium citrate solid is added into 100mL of deionized water, and stirring is performed to obtain a uniformly dispersed sodium citrate solution;

[0064] (2) 1g of agarose powder is added into the sodium citrate solution, and ultrasonic stirring is performed for 5min to obtain a uniformly dispersed mixed solution;

[0065] (3) The mixed solution is heated in a microwave oven at 90℃ for 5min;

[0066] The slightly cooled mixed solution after heating is poured into a gel plate, and is solidified for 30min to obtain a sodium citrate-agarose gel.

[0067] (4) The gel electrophoresis method is used for separating noble metal ions, and the ionic noble metals loaded on the sodium citrate-agarose gel are reduced to obtain two kinds of noble metals of gold and palladium.

[0068] The simulated actual leaching solution is dropped into the gel hole for experiment by using a gel electrophoresis device under the control of 80V voltage and 80mA current, and the reaction time is 90min. Finally, the color development gel strip of a specified distance is taken for digestion, the content of noble metal in different color development gel strips is quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0069] Example 3

[0070] The application discloses a method for selectively separating and reducing noble metals by using gel electrophoresis, comprising the following steps:

[0071] (1) 0.75g of sodium citrate solid is added into 100mL of deionized water, and stirring is conducted to obtain a uniformly dispersed sodium citrate solution;

[0072] (2) 5g of agarose powder is added into the sodium citrate solution, and ultrasonic stirring is conducted for 5min to obtain a uniformly dispersed mixed solution;

[0073] (3) The mixed solution is heated in a microwave oven at 90℃ for 4min;

[0074] The slightly cooled mixed solution after heating is poured into a gel plate, and is solidified for 30min to obtain a sodium citrate-agarose gel.

[0075] (4) The gel electrophoresis method is used for separating noble metal ions, and the ionic noble metals loaded on the sodium citrate-agarose gel are reduced to obtain two kinds of noble metals of gold and palladium. Specifically, the following is conducted:

[0076] The simulated actual leaching solution is dropped into the gel hole for experiment by using a gel electrophoresis device under the control of 100V voltage and 100mA current, and the reaction time is 90min. Finally, the color development gel strip of a specified distance is taken for digestion, the content of noble metal in different color development gel strips is quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0077] Example 4

[0078] The application discloses a method for selectively separating and reducing noble metals by using gel electrophoresis, comprising the following steps:

[0079] (1) 1g of sodium citrate solid is added into 100mL of deionized water, and stirring is conducted to obtain a uniformly dispersed sodium citrate solution;

[0080] (2) 2g of agarose powder is added into the sodium citrate solution, and ultrasonic stirring is conducted for 5min to obtain a uniformly dispersed mixed solution;

[0081] (3) The mixed solution is heated in a microwave oven at 90℃ for 4min;

[0082] The slightly cooled mixed solution after heating is poured into a gel plate to solidify for 30 min to obtain a sodium citrate-agarose gel.

[0083] (4) The noble metal ions are separated by using the gel electrophoresis method, and the ionic noble metals loaded on the sodium citrate-agarose gel are reduced to obtain two kinds of noble metals of gold and palladium. Specifically as follows:

[0084] The simulated actual leaching solution is dropped into the gel hole for experiment by using a gel electrophoresis device under the control of a voltage of 40 V and a current of 40 mA, and the reaction time is 30 min. Finally, the color-developed gel bands at a specified distance are digested, the content of noble metals in different color-developed gel bands is quantitatively analyzed by using ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0085] Example 5

[0086] The application discloses a method for selectively separating and reducing noble metals by using gel electrophoresis, comprising the following steps:

[0087] (1) 1.25 g of sodium citrate solid is added into 100 mL of deionized water to be stirred to obtain a uniformly dispersed sodium citrate solution;

[0088] (2) 5 g of agarose powder is added into the sodium citrate solution to be ultrasonically stirred for 5 min to obtain a uniformly dispersed mixed solution;

[0089] (3) The mixed solution is heated in a microwave oven at 120 DEG C for 3 min;

[0090] The slightly cooled mixed solution after heating is poured into a gel plate to solidify for 30 min to obtain a sodium citrate-agarose gel.

[0091] (4) The noble metal ions are separated by using the gel electrophoresis method, and the ionic noble metals loaded on the sodium citrate-agarose gel are reduced to obtain two kinds of noble metals of gold and palladium. Specifically as follows:

[0092] The simulated actual leaching solution is dropped into the gel hole for experiment by using a gel electrophoresis device under the control of a voltage of 60 V and a current of 60 mA, and the reaction time is 15 min. Finally, the color-developed gel bands at a specified distance are digested, the content of noble metals in different color-developed gel bands is quantitatively analyzed by using ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0093] Example 6

[0094] The application discloses a method for selectively separating and reducing noble metals by using gel electrophoresis, comprising the following steps:

[0095] (1) 1.5g sodium citrate solid was added into 100ml deionized water, and stirred to obtain a uniformly dispersed sodium citrate solution;

[0096] (2) 3g agarose powder was added into the above sodium citrate solution, and ultrasonically stirred for 5min to obtain a uniformly dispersed mixed solution;

[0097] (3) The mixed solution was heated in a microwave oven at 90℃ for 4min;

[0098] The slightly cooled mixed solution after heating was poured into a gel plate, and solidified for 30min to obtain a sodium citrate-agarose gel.

[0099] (4) The noble metal ions were separated by gel electrophoresis, and the ionic noble metals loaded on the sodium citrate-agarose gel were reduced to obtain two kinds of noble metals of gold and palladium. Specifically as follows:

[0100] The simulated actual leaching solution was dropped into the gel hole for experiment by using a gel electrophoresis device under the control of a voltage of 80V and a current of 80mA, and the reaction time was 30min. Finally, the color-developed gel strips of a specified distance were digested, and the contents of noble metals in different color-developed gel strips were quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0101] Comparative example

[0102] The application discloses a method for selectively separating and reducing noble metals by using gel electrophoresis, comprising the following steps:

[0103] (1) 3g agarose powder was added into deionized water, and ultrasonically stirred for 5min to obtain a uniformly dispersed agarose solution;

[0104] (2) The agarose solution was heated in a microwave oven at 90℃ for 4min;

[0105] (3) The slightly cooled agarose solution after heating was poured into a gel plate, and solidified for 30min to obtain an agarose gel.

[0106] In the experiment of selectively separating and reducing gold and palladium from a solution containing noble metals, the simulated actual leaching solution was dropped into the gel hole for experiment by using a gel electrophoresis device under the control of a voltage of 60V and a current of 60mA, and the reaction time was 30min. Finally, the color-developed gel strips of a specified distance were digested, and the contents of noble metals in different color-developed gel strips were quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel. It is found that the agarose gel only separates and reduces gold particles under the electrophoresis of electrophoresis.

[0107] In the experiment of selectively separating reduced gold and palladium from the solution containing noble metal, the simulated actual leaching solution was dropped into the gel hole in the control of 60mA current by using the gel electrophoresis device, and the reaction time was 60min. The color developing gel band of the specified distance was finally taken for digestion, and the content of noble metal in different color developing gel bands was quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel.

[0108] In the experiment of selectively separating reduced gold and palladium from the solution containing noble metal by using the gel electrophoresis technology, the selective separation of gold and palladium in example 1 to example 7 was carried out at room temperature, the color developing gel band of the specified distance was taken for digestion, and the content of noble metal in different color developing gel bands was quantitatively analyzed by ICP-MS, so as to calculate the separation rate of different noble metal particles in the gel. Figure 6 、 Figure 7 As shown in the table.

[0109] As shown in the table. Figure 6 It can be seen that when the content of the reducing agent sodium citrate reaches 0.5g, the separation rate of gold and palladium particles reaches the maximum, which is 92.22% and 90.53% respectively.

[0110] As shown in the table. Figure 7 It can be seen that when the agarose concentration reaches 3%, the separation rate of gold and palladium particles reaches the maximum, which is 92.22% and 90.53% respectively.

[0111] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the specific embodiments of the present application can still be modified or replaced by the equivalent, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered in the protection scope of the claims of the present application.

Claims

1. A method for selectively separating reduced noble metals by gel electrophoresis, characterized by, The method comprises the following steps: (1) adding agarose powder into sodium citrate solution, and stirring by ultrasonic to obtain a mixed solution with uniform dispersion; (2) heating the mixed solution, cooling it, pouring the cooled mixed solution into a gel plate, and solidifying to obtain sodium citrate-agarose gel; (3) separating noble metal ions by gel electrophoresis, and reducing the noble metal ions loaded on the sodium citrate-agarose gel to obtain gold and palladium and other noble metals.

2. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (1), the preparation process of the sodium citrate solution is as follows: adding sodium citrate solid into deionized water, and stirring to obtain a uniformly dispersed sodium citrate solution.

3. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, The mass ratio of sodium citrate to agarose is (0.25-1.5):(1-5).

4. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (1), the concentration of agarose in the mixed solution is 1%-5%.

5. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (1), the stirring time by ultrasonic is 5-10 min.

6. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (2), the heating temperature is 90-120℃, and the heating time is 3-5 min.

7. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (2), after the mixed solution is poured into the gel plate, it becomes semi-solid at 35-40℃, and then becomes gel state, thus obtaining sodium citrate-agarose gel.

8. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (3), the parameters of the gel electrophoresis are as follows: voltage is 40-100V, and current is 40-100mA.

9. The method for selectively separating reduced noble metals by gel electrophoresis according to claim 1, characterized in that, In step (3), the electrophoresis liquid of the gel electrophoresis is sodium chloride solution.

Images