A digestion method of AgCuZn alloy suitable for ICP-OES analysis

Abstract

The application belongs to the technical field of analytical testing, and relates to a digestion method suitable for ICP-OES analysis of AgCuZn alloy, comprising the following steps: (1) mixing AgCuZn alloy with compounded acid, wherein the compounded acid is compounded by nitric acid solution and hydrofluoric acid solution; (2) performing step-by-step ultrasonic treatment on the mixture obtained in step (1); (3) performing step-by-step heating treatment on the mixture obtained after ultrasonic treatment in step (2) until a clear solution is obtained; and (4) placing the clear solution obtained in step (3) for cooling, diluting and constant volume to obtain a to-be-tested solution suitable for ICP-OES analysis. The digestion method provided by the application realizes the technical targets of efficient dissolution, precise adaptation and stable reliability in view of the chemical characteristics of different metals in AgCuZn alloy and the sample preparation requirements of ICP-OES analysis, and takes into account the collaborative dissolution of multiple elements and the adaptation of multiple forms, and the process parameters are controllable, which is conducive to large-scale popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of analytical testing technology and relates to an alloy digestion method, particularly an AgCuZn alloy digestion method suitable for ICP-OES analysis. Background Technology

[0002] Inductively coupled plasma optical emission spectrometry (ICP-OES) has become a core instrument for the quantitative detection of metallic elements in alloys due to its advantages of low interference, stable signal, and ease of operation. Its detection accuracy is directly related to the alloy digestion effect in the pretreatment stage. Only when the alloy is fully dissolved into a clear, homogeneous acid solution can the accuracy of subsequent element content testing be guaranteed. In fields such as jewelry manufacturing, electronic connectors, and precision instruments, silver-copper-zinc (AgCuZn) alloys are widely used due to their excellent ductility, conductivity, and corrosion resistance. The main contents of Ag, Cu, and Zn directly determine the mechanical properties and application scenarios of the alloy (e.g., high-Ag content alloys are used in jewelry, and high-Cu content alloys are used in electronic contacts). Therefore, there is an urgent need for efficient digestion methods suitable for ICP-OES analysis.

[0003] However, the digestion of AgCuZn alloys faces numerous technical bottlenecks, stemming from the fundamental differences in the chemical properties of the three metals: Silver (Ag) is only soluble in nitric acid at room temperature, reacts weakly with sulfuric acid and hydrochloric acid, and readily forms black silver sulfide (Ag₂S) with sulfur in the environment, hindering acid penetration; Copper (Cu) is a relatively stable transition metal, reacting slowly with nitric acid at room temperature, requiring specific temperature activation, and is insoluble in dilute hydrochloric acid and dilute sulfuric acid; Zinc (Zn), while reactive, readily forms a dense protective film of zinc oxide (ZnO) or basic zinc carbonate on its surface, which is difficult to break down quickly with conventional acids. The synergistic dissolution requirements of these three metals make it difficult for a single acid system or a general digestion scheme to meet the requirements.

[0004] Existing ICP-OES sample preparation methods for AgCuZn alloys have significant drawbacks: First, early methods often employed a single "nitric acid + water" system, relying on natural dissolution at room temperature. This was not only time-consuming but also prone to incomplete dissolution in alloys with surface oxidation or high Ag content (>90%). The residual microparticles in the solution caused fluctuations in the ICP-OES test signal, resulting in a relatively high standard deviation. Second, key parameters such as solid-liquid ratio and acid concentration lacked quantitative ranges, making them unsuitable for AgCuZn alloys with different composition ratios and exhibiting poor universality. Third, the differences in alloy morphology were not considered. Block / foil samples were prone to localized incomplete dissolution due to limited contact area, while powder / debris samples tended to agglomerate, preventing acid penetration and failing to meet practical application requirements.

[0005] While some patents propose a "compound acid + ultrasound / heating" digestion approach for copper-based alloys (such as CuMn and CuAl), these solutions are designed for single copper-based alloys and cannot be directly applied to AgCuZn alloys. For example, the acid ratio for CuMn and CuAl alloys needs to be adapted to the solubility characteristics of Mn and Al. If directly applied to AgCuZn alloys, either excessive hydrofluoric acid will cause AgNO3 saturation precipitation (Ag does not react with hydrofluoric acid), or insufficient hydrofluoric acid will fail to break down the Zn oxide film.

[0006] Furthermore, practical testing faces unique challenges in specific scenarios: for example, the silver sulfide layer formed on the surface of AgCuZn alloys after long-term storage requires prolonged immersion in conventional acid solutions to remove; AgCuZn waste generated in the electronics industry is mostly composed of fine fragments that easily agglomerate, leading to acid encapsulation; and high-purity AgCuZn foils require careful handling to avoid sample loss due to overheating. Existing solutions do not provide optimization strategies for these scenarios, resulting in a technical gap in ICP-OES analysis of AgCuZn alloys, characterized by low dissolution efficiency, poor adaptability, and unstable accuracy. Therefore, a highly efficient sample preparation method that can simultaneously achieve multi-element synergistic dissolution, multi-morphological adaptability, and controllable parameters is urgently needed. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an AgCuZn alloy digestion method suitable for ICP-OES analysis, achieving the technical goals of efficient dissolution, accurate adaptation, and stable reliability, while also taking into account multi-element synergistic dissolution and multi-morphological adaptation, and with controllable process parameters.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] This invention provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis, comprising the following steps:

[0010] (1) A mixture of AgCuZn alloy and a compound acid, wherein the compound acid is prepared by mixing nitric acid solution and hydrofluoric acid solution;

[0011] (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment;

[0012] (3) The ultrasonically treated mixture obtained in step (2) is subjected to stepwise heating treatment until a clear solution is obtained;

[0013] (4) Allow the clear solution obtained in step (3) to stand and cool, then dilute and bring to volume to obtain a test solution suitable for ICP-OES analysis.

[0014] This invention employs a compound acid to digest AgCuZn alloys, combining stepwise ultrasonic and stepwise heating treatments during the digestion process to achieve complete dissolution of the alloys, thereby improving processing efficiency and process adaptability. Specifically, nitric acid solution efficiently dissolves Ag and Cu in the alloy, while hydrofluoric acid solution specifically breaks down the dense zinc oxide or basic zinc carbonate on the Zn surface, generating soluble zinc fluorofluoride. The combination of these two solutions ensures the complete dissolution of Ag, Cu, and Zn from the alloy, laying the foundation for signal stability in ICP-OES analysis.

[0015] Preferably, the Ag content in the AgCuZn alloy in step (1) is 80-95wt%, the Cu content is 3-15wt%, and the Zn content is 2-10wt%.

[0016] Preferably, the AgCuZn alloy in step (1) is in the form of blocks, foils, chips or powder.

[0017] Preferably, the solid-liquid ratio of the AgCuZn alloy and the compound acid in step (1) is 1g:(25-45)mL.

[0018] Preferably, the volume ratio of nitric acid solution to hydrofluoric acid solution in the compound acid in step (1) is (2-3):1.

[0019] Preferably, the concentration of the nitric acid solution is 65-68 wt%, and the concentration of the hydrofluoric acid solution is 34-38 wt%.

[0020] Preferably, when the AgCuZn alloy in step (1) is in the form of chips or powder, the mixing method is as follows: first mix the AgCuZn alloy with half a volume of compound acid, then ultrasonically treat it, and then add the other half volume of compound acid.

[0021] Preferably, when the surface of the AgCuZn alloy in step (1) has sulfides or oxide layers, hydrogen peroxide is also added to the compound acid.

[0022] Preferably, the amount of hydrogen peroxide added is 0.5-1 wt%.

[0023] Preferably, the stepwise ultrasound treatment in step (2) includes: first performing low-power ultrasound of 200-400W, and then performing high-power ultrasound of 500-700W.

[0024] Preferably, the duration of the low-power ultrasound is 2-3 minutes, and the duration of the high-power ultrasound is 3-5 minutes.

[0025] Preferably, when the AgCuZn alloy in step (1) is in the form of a block or foil, the step-by-step ultrasonic treatment in step (2) is performed by flipping the AgCuZn alloy after the low-power ultrasonic treatment ends and before the high-power ultrasonic treatment begins.

[0026] Preferably, the step-by-step heating process in step (3) includes: first performing low-temperature heating at 80-90°C, and then performing high-temperature heating at 90-95°C.

[0027] Preferably, the heating time for low-temperature heating is 2-3 minutes, and the holding time is 1-2 minutes; the heating time for high-temperature heating is 1-2 minutes, and the holding time is 1-2 minutes.

[0028] Preferably, the stepwise heating process in step (3) is accompanied by ultrasonic treatment, and the power of the ultrasonic treatment is 400-500W.

[0029] Preferably, the static cooling in step (4) to the final temperature is 25-35°C.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This invention employs a compound acid to digest AgCuZn alloys, combining stepwise ultrasonic and stepwise heating treatments during the digestion process to achieve complete dissolution of the alloys, thereby improving processing efficiency and process adaptability. Specifically, nitric acid solution efficiently dissolves Ag and Cu in the alloy, while hydrofluoric acid solution specifically breaks down the dense zinc oxide or basic zinc carbonate on the Zn surface, generating soluble zinc fluorofluoride. The combination of these two solutions ensures the complete dissolution of Ag, Cu, and Zn from the alloy, laying the foundation for signal stability in ICP-OES analysis. Detailed Implementation

[0032] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0033] One embodiment of the present invention provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis, comprising the following steps:

[0034] (1) A mixture of AgCuZn alloy and a compound acid, wherein the compound acid is prepared by mixing nitric acid solution and hydrofluoric acid solution;

[0035] (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment;

[0036] (3) The ultrasonically treated mixture obtained in step (2) is subjected to stepwise heating treatment until a clear solution is obtained;

[0037] (4) Allow the clear solution obtained in step (3) to stand and cool, then dilute and bring to volume to obtain a test solution suitable for ICP-OES analysis.

[0038] This invention employs a compound acid to digest AgCuZn alloys, combining stepwise ultrasonic and stepwise heating treatments during the digestion process to achieve complete dissolution of the alloys, thereby improving processing efficiency and process adaptability. Specifically, nitric acid solution efficiently dissolves Ag and Cu in the alloy, while hydrofluoric acid solution specifically breaks down the dense zinc oxide or basic zinc carbonate on the Zn surface, generating soluble zinc fluorofluoride. The combination of these two solutions ensures the complete dissolution of Ag, Cu, and Zn from the alloy, laying the foundation for signal stability in ICP-OES analysis.

[0039] In some embodiments, the Ag content in the AgCuZn alloy in step (1) is 80-95 wt%, for example, it can be 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, or 95 wt%, the Cu content is 3-15 wt%, for example, it can be 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%, and the Zn content is 2-10 wt%, for example, it can be 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0040] The digestion method provided by this invention is compatible with the mainstream AgCuZn alloy composition range, covering core application scenarios such as jewelry (high Ag), electronic contacts (high Cu), and precision parts (balanced composition), and effectively solves the limitation of existing solutions that are only compatible with single-component alloys.

[0041] In some embodiments, the AgCuZn alloy in step (1) may be in the form of a block, foil, chips or powder.

[0042] In some embodiments, the solid-liquid ratio of the AgCuZn alloy and the compound acid in step (1) is 1g:(25-45)mL, for example, it can be 1g:25mL, 1g:30mL, 1g:35mL, 1g:40mL or 1g:45mL, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] The solid-liquid ratio specified in this invention is suitable for AgCuZn alloys with different Ag contents. It not only meets the dissolution requirements of high Ag content alloys and prevents excessive precipitation of AgNO3, but is also applicable to low Ag content alloys, avoiding acid waste.

[0044] In some embodiments, the volume ratio of nitric acid solution to hydrofluoric acid solution in the compound acid in step (1) is (2-3):1, for example, it can be 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1 or 3:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] This invention limits the volume ratio of nitric acid solution and hydrofluoric acid solution to a reasonable range, which not only avoids the saturation precipitation of AgNO3 due to excessive hydrofluoric acid, but also prevents incomplete dissolution of Zn due to insufficient hydrofluoric acid. Ultimately, it ensures that Ag, Cu and Zn are 100% dissolved, thereby obtaining a clear solution without residue.

[0046] In some embodiments, the concentration of the nitric acid solution is 65-68 wt%, for example, it can be 65 wt%, 65.5 wt%, 66 wt%, 66.5 wt%, 67 wt%, 67.5 wt%, or 68 wt%, and the concentration of the hydrofluoric acid solution is 34-38 wt%, for example, it can be 34 wt%, 34.5 wt%, 35 wt%, 35.5 wt%, 36 wt%, 36.5 wt%, 37 wt%, 37.5 wt%, or 38 wt%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0047] In some embodiments, when the AgCuZn alloy in step (1) is in the form of chips or powder, the mixing method is as follows: first mix the AgCuZn alloy with half a volume of compound acid, then sonicate it, and then add the other half volume of compound acid.

[0048] Since fragments / powdered alloys are prone to agglomeration, which can cause acid to encapsulate them and prevent them from penetrating the internal particles, this invention first mixes AgCuZn alloy with half the volume of compound acid, sonicates it, and then adds the other half volume of compound acid. This ensures that each fragment / powder is in full contact with the acid, significantly improving the thoroughness of dissolution and avoiding deviations in test results caused by agglomeration.

[0049] In some embodiments, when the surface of the AgCuZn alloy in step (1) has sulfides or oxide layers, hydrogen peroxide is also added to the compound acid.

[0050] In this invention, hydrogen peroxide can specifically oxidize and break down the oxide layers of silver sulfide and basic zinc carbonate to generate soluble sulfates / carbonates without the need for long-term soaking. Furthermore, hydrogen peroxide eventually decomposes into water and oxygen, leaving no residual impurities that could interfere with the detection results.

[0051] In some embodiments, the amount of hydrogen peroxide added is 0.5-1 wt%, for example, it can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt% or 1 wt%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0052] In some embodiments, the stepwise ultrasound processing in step (2) includes: first performing low-power ultrasound of 200-400W, and then performing high-power ultrasound of 500-700W.

[0053] In this invention, low-power ultrasound can break the liquid film on the alloy surface, allowing the compounded acid to quickly penetrate into the alloy body; high-power ultrasound enhances acid convection and accelerates the dissolution of metal ions. Compared with single-power ultrasound, stepwise ultrasound treatment significantly shortens the dissolution time.

[0054] The power of the low-power ultrasound is 200-400W, for example, it can be 200W, 220W, 240W, 260W, 280W, 300W, 320W, 340W, 360W, 380W or 400W. The power of the high-power ultrasound is 500-700W, for example, it can be 500W, 520W, 540W, 560W, 580W, 600W, 620W, 640W, 660W, 680W or 700W, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0055] In some embodiments, the duration of the low-power ultrasound is 2-3 minutes, for example, 2 minutes, 2.1 minutes, 2.2 minutes, 2.3 minutes, 2.4 minutes, 2.5 minutes, 2.6 minutes, 2.7 minutes, 2.8 minutes, 2.9 minutes, or 3 minutes; and the duration of the high-power ultrasound is 3-5 minutes, for example, 3 minutes, 3.2 minutes, 3.4 minutes, 3.6 minutes, 3.8 minutes, 4 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes, or 5 minutes, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0056] In some embodiments, when the AgCuZn alloy in step (1) is in the form of a block or foil, the step-by-step ultrasonic treatment in step (2) is performed by flipping the AgCuZn alloy after the low-power ultrasonic treatment ends and before the high-power ultrasonic treatment begins.

[0057] Since the contact area of ​​block / foil alloys is limited, the bottom is prone to undissolved particles. Flipping the sample allows both sides to fully contact the compound acid, avoiding local dissolution blind spots and thus significantly reducing the undissolved particle rate.

[0058] In some embodiments, the step-by-step heating process in step (3) includes: first performing low-temperature heating at 80-90°C, and then performing high-temperature heating at 90-95°C.

[0059] In this invention, low-temperature heating can activate the reaction between Cu and nitric acid, high-temperature heating can ensure complete dissolution of Zn, and the maximum temperature <100℃ can avoid high-temperature decomposition of AgNO3 and eliminate impurity interference.

[0060] The low-temperature heating temperature is 80-90℃, for example, it can be 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃ or 90℃. The high-temperature heating temperature is 90-95℃, for example, it can be 90℃, 90.5℃, 91℃, 91.5℃, 92℃, 92.5℃, 93℃, 93.5℃, 94℃, 94.5℃ or 95℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0061] In some embodiments, the heating time for low-temperature heating is 2-3 minutes, for example, 2 minutes, 2.1 minutes, 2.2 minutes, 2.3 minutes, 2.4 minutes, 2.5 minutes, 2.6 minutes, 2.7 minutes, 2.8 minutes, 2.9 minutes, or 3 minutes; the holding time is 1-2 minutes, for example, 1 minute, 1.1 minutes, 1.2 minutes, 1.3 minutes, 1.4 minutes, 1.5 minutes, 1.6 minutes, 1.7 minutes, 1.8 minutes, 1.9 minutes, or 2 minutes; the heating time for high-temperature heating is... The holding time is 1-2 minutes, for example, it can be 1 minute, 1.1 minutes, 1.2 minutes, 1.3 minutes, 1.4 minutes, 1.5 minutes, 1.6 minutes, 1.7 minutes, 1.8 minutes, 1.9 minutes or 2 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0062] In some embodiments, the stepwise heating process described in step (3) is accompanied by ultrasonic treatment, and the power of the ultrasonic treatment is 400-500W, for example, it can be 400W, 410W, 420W, 430W, 440W, 450W, 460W, 470W, 480W, 490W or 500W, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0063] In some embodiments, the step (4) of allowing the water to cool to a final temperature of 25-35°C, for example, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0064] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0065] Example 1

[0066] This embodiment provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis, including the following steps:

[0067] (1) First, mix the fragmented AgCuZn alloy with half the volume of the compound acid, and then ultrasonically treat it with 200W power for 1 minute. Then add the other half volume of the compound acid. The overall solid-liquid ratio is 1g:35mL. The compound acid is composed of a nitric acid solution (concentration of 66wt%) and a hydrofluoric acid solution (concentration of 35wt%) with a volume ratio of 2:1.

[0068] (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment, specifically: first, 300W low-power ultrasonic treatment for 2 minutes, and then 600W high-power ultrasonic treatment for 5 minutes.

[0069] (3) The mixture obtained after ultrasound in step (2) is subjected to stepwise heating treatment, specifically: first, the temperature is raised to 85°C within 2 minutes for low-temperature heating for 2 minutes, and then the temperature is raised to 90°C within 1 minute for high-temperature heating for 2 minutes, accompanied by ultrasound treatment of 400W during the heating process, until a clear solution is obtained.

[0070] (4) Allow the clear solution obtained in step (3) to stand and cool to a final temperature of 30°C, then dilute and bring the volume to a final volume of 100 mL to obtain a test solution suitable for ICP-OES analysis.

[0071] Example 2

[0072] This embodiment provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis, including the following steps:

[0073] (1) First, mix powdered AgCuZn alloy with half the volume of compound acid, and ultrasonically treat it with 200W power for 1 minute. Then add the other half volume of compound acid. The overall solid-liquid ratio is 1g:25mL. The compound acid is composed of nitric acid solution (concentration of 65wt%) and hydrofluoric acid solution (concentration of 38wt%) with a volume ratio of 3:1.

[0074] (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment, specifically: first, 200W low-power ultrasonic treatment for 3 minutes, and then 500W high-power ultrasonic treatment for 3 minutes.

[0075] (3) The mixture obtained after ultrasound in step (2) is subjected to stepwise heating treatment, specifically: first, the temperature is raised to 80°C within 2 minutes for low-temperature heating for 2 minutes, and then the temperature is raised to 95°C within 2 minutes for high-temperature heating for 1 minute, and ultrasound treatment of 500W is carried out during the heating process until a clear solution is obtained.

[0076] (4) Allow the clear solution obtained in step (3) to stand and cool to a final temperature of 25°C, then dilute and bring the volume to a final volume of 100 mL to obtain a test solution suitable for ICP-OES analysis.

[0077] Example 3

[0078] This embodiment provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis, including the following steps:

[0079] (1) Mix blocky AgCuZn alloy and compound acid with a solid-liquid ratio of 1g:45mL, wherein the compound acid is prepared by mixing nitric acid solution (concentration of 68wt%) and hydrofluoric acid solution (concentration of 34wt%) in a volume ratio of 2:1.

[0080] (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment, specifically: first, 400W low power ultrasonic treatment for 2 minutes, then the alloy is flipped over and subjected to 700W high power ultrasonic treatment for 5 minutes.

[0081] (3) The mixture obtained after ultrasound in step (2) is subjected to stepwise heating treatment, specifically: first, the temperature is raised to 90°C within 3 minutes for low-temperature heating for 2 minutes, and then the temperature is raised to 95°C within 1 minute for high-temperature heating for 2 minutes, accompanied by ultrasound treatment of 500W during the heating process, until a clear solution is obtained.

[0082] (4) Allow the clear solution obtained in step (3) to stand and cool to a final temperature of 35°C, then dilute and bring the volume to a final volume of 100 mL to obtain a test solution suitable for ICP-OES analysis.

[0083] Example 4

[0084] This embodiment provides a digestion method for AgCuZn alloy suitable for ICP-OES analysis. Except for replacing the blocky AgCuZn alloy with an equal mass of foil-shaped AgCuZn alloy, the other steps and conditions are the same as in Example 3, so they will not be repeated here.

[0085] Example 5

[0086] This embodiment provides a digestion method for AgCuZn alloys suitable for ICP-OES analysis. Except for the addition of 1 wt% hydrogen peroxide in the compound acid, the other steps and conditions are the same as in Example 3, so they will not be described in detail here.

[0087] Example 6

[0088] This embodiment provides a digestion method for AgCuZn alloy suitable for ICP-OES analysis. Except for changing the mixing method of step (1) to a one-step mixing, that is, directly mixing AgCuZn alloy with the full volume of compound acid, the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0089] Example 7

[0090] This embodiment provides a digestion method for AgCuZn alloy suitable for ICP-OES analysis. Except for the alloy flipping operation in step (2), the other steps and conditions are the same as in Example 3, so they will not be repeated here.

[0091] Example 8

[0092] This embodiment provides a digestion method for AgCuZn alloy suitable for ICP-OES analysis. Except for the absence of ultrasonic treatment in step (3), the other steps and conditions are the same as in Example 3, so they will not be repeated here.

[0093] Comparative Example 1

[0094] This comparative example provides a method for digesting AgCuZn alloy. Except for replacing the compound acid with an equal volume of single nitric acid solution (concentration of 66wt%), the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0095] Comparative Example 2

[0096] This comparative example provides a method for digesting AgCuZn alloy. Except for the stepwise ultrasonic treatment in step (2), which is not performed, the stepwise heating treatment is performed directly. The other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0097] Comparative Example 3

[0098] This comparative example provides a method for digesting AgCuZn alloy. Except that the step-by-step heating treatment in step (2) is changed to a one-step heating treatment, that is, the temperature is raised to 95°C within 4 minutes and heated at high temperature for 2 minutes, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0099] Tests and Results

[0100] Examples 1-8 and Comparative Examples 1-3 all used AgCuZn alloys with the same standard composition (Ag 92wt%, Cu 3wt%, Zn 5wt%). The Zn content of the obtained test solutions was tested using an Agilent 5100IPC-OES plasma emission spectrometer for precision testing.

[0101] The alloy digestion methods provided in Examples 1-8 and Comparative Examples 1-3 were evaluated by precision tests. Each sample was tested three times. The test results of Zn content in the test solution are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] Therefore, this invention employs a compound acid to digest the AgCuZn alloy, combining stepwise ultrasonic and stepwise heating treatments during the digestion process to achieve complete dissolution of the alloy, thereby improving processing efficiency and process adaptability. Specifically, nitric acid solution efficiently dissolves Ag and Cu in the alloy, while hydrofluoric acid solution specifically breaks down the dense zinc oxide or basic zinc carbonate on the Zn surface, generating soluble zinc fluorophosphates. The combination of these two solutions ensures the complete dissolution of Ag, Cu, and Zn from the alloy, laying the foundation for signal stability in ICP-OES analysis.

[0105] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A digestion method for AgCuZn alloys suitable for ICP-OES analysis, characterized in that, The method for digesting AgCuZn alloy includes the following steps: (1) A mixture of AgCuZn alloy and a compound acid, wherein the compound acid is prepared by mixing nitric acid solution and hydrofluoric acid solution; (2) The mixture obtained in step (1) is subjected to stepwise ultrasonic treatment; (3) The ultrasonically treated mixture obtained in step (2) is subjected to stepwise heating treatment until a clear solution is obtained; (4) Allow the clear solution obtained in step (3) to stand and cool, then dilute and bring to volume to obtain a test solution suitable for ICP-OES analysis.

2. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1, characterized in that, In step (1), the AgCuZn alloy contains 80-95 wt% Ag, 3-15 wt% Cu, and 2-10 wt% Zn. And / or, the form of the AgCuZn alloy in step (1) includes bulk, foil, chips or powder.

3. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, In step (1), the solid-liquid ratio of the AgCuZn alloy and the compound acid is 1g:(25-45)mL; And / or, the volume ratio of nitric acid solution and hydrofluoric acid solution in the compound acid in step (1) is (2-3):1; The concentration of the nitric acid solution is 65-68 wt%, and the concentration of the hydrofluoric acid solution is 34-38 wt%.

4. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, When the AgCuZn alloy in step (1) is in the form of chips or powder, the mixing method is as follows: first mix the AgCuZn alloy with half a volume of compound acid, then ultrasonically treat it, and then add the other half volume of compound acid.

5. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, When the surface of the AgCuZn alloy in step (1) has sulfides or oxide layers, hydrogen peroxide is also added to the compound acid. The amount of hydrogen peroxide added is 0.5-1 wt%.

6. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, The step-by-step ultrasound treatment in step (2) includes: first performing low-power ultrasound of 200-400W, and then performing high-power ultrasound of 500-700W. The duration of the low-power ultrasound is 2-3 minutes, and the duration of the high-power ultrasound is 3-5 minutes.

7. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 6, characterized in that, When the AgCuZn alloy in step (1) is in the form of a block or foil, the step-by-step ultrasonic treatment in step (2) is as follows: after the low-power ultrasonic treatment ends and before the high-power ultrasonic treatment begins, the AgCuZn alloy is flipped over.

8. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, The step-by-step heating process in step (3) includes: first heating at a low temperature of 80-90℃, and then heating at a high temperature of 90-95℃; The heating time for the low-temperature heating is 2-3 minutes, and the holding time is 1-2 minutes; the heating time for the high-temperature heating is 1-2 minutes, and the holding time is 1-2 minutes.

9. The AgCuZn alloy digestion method suitable for ICP-OES analysis according to claim 1 or 2, characterized in that, In step (3), the stepwise heating process is accompanied by ultrasonic treatment, and the power of the ultrasonic treatment is 400-500W.

10. The method for digesting AgCuZn alloys suitable for ICP-OES analysis according to claim 1 or 2, characterized in that step (4) involves static cooling to a final temperature of 25-35°C.

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