Method for detecting impurity aluminum in high-purity indium
Through the method of dissolution of concentrated nitric acid and precipitation reaction of hydrofluoric acid, the detection problem of low-content aluminum in high-purity indium is solved, fast and accurate detection results are achieved, and the complexity of the laboratory equipment and operation is reduced.
Patent Information
- Application Number
- CN202510249773.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-04
- Publication Date
- 2025-05-13
AI Technical Summary
The prior art is difficult to quickly and accurately detect the impurity element aluminum in high-purity indium, and the commonly used methods are complex in operation and expensive in equipment, which cannot meet the needs of high-purity indium production and trade settlement.
After using concentrated nitric acid to dissolve high-purity indium, hydrofluoric acid is used for precipitation reaction, filtrate is obtained by solid-liquid separation, and interference from indium elements is removed, and the aluminum content is determined by inductively coupled plasma mass spectrometer.
It realizes rapid and accurate detection of impurity aluminum in high-purity indium, with reliable detection results and low detection limits. It is suitable for most laboratories to implement, and is of great significance to guide the production and trade settlement of high-purity indium.
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Abstract
Description
Technical Field
[0001] The invention relates to a method for detecting impurity aluminum in high-purity indium, belonging to the technical field of analysis and detection. Background Art
[0002] Indium is a metal element with the symbol In and the atomic number 49. It is located in the fifth period of the periodic table, group IIIA. Its single substance is a silvery white metal with a slightly bluish color. It is very soft and can be scratched with a fingernail. It is highly plastic and ductile and can be pressed into sheets.
[0003] Indium is a rare metal and a scarce resource. Since no independent indium mines have been found, the industry produces metallic indium by purifying waste zinc and waste tin. The extraction process of indium is mainly based on extraction-electrolysis, which is also the mainstream process technology for indium production in the world today. Its principle process flow is: indium-containing raw materials → enrichment → chemical dissolution → purification → extraction → stripping → zinc (aluminum) replacement → sponge indium → electrolytic refining → refined indium.
[0004] Industrial production uses industrial-grade metallic indium as raw material, and uses electrolysis, vacuum distillation, and direct pulling to produce high-purity indium. Through electrolytic refining and other processes, the purity of high-purity indium is ≥99.999%. Using ≥99.999% high-purity indium as raw material, the purity of high-purity indium produced through vacuum distillation, pulling and other processes can reach 99.99999%.
[0005] Impurity aluminum in high-purity indium is one of the impurity elements that is relatively difficult to remove in the indium production process. The amount of impurity aluminum in metallic indium determines the quality of metallic indium. Therefore, the detection of trace aluminum in high-purity indium is extremely important.
[0006] Industry standard "YS / T 981.1-2014 High-purity indium chemical analysis method - Determination of magnesium, aluminum, silicon, sulfur, iron, nickel, copper, zinc, arsenic, silver, cadmium, tin, thallium and lead - high mass resolution glow discharge mass spectrometry" (hereinafter referred to as high mass resolution glow discharge mass spectrometry, abbreviated as GD-MS). In this method, a high mass resolution glow discharge mass spectrometer is required for determination. This equipment is relatively expensive and is not generally available in laboratories.
[0007] The industry standard "YS / T 981.2-2014 High-purity Indium Chemical Analysis Method Determination of Magnesium, Aluminum, Iron, Nickel, Copper, Zinc, Silver, Cadmium, Tin and Lead Inductively Coupled Plasma Mass Spectrometry" uses hydrobromic acid to dissolve and isopropyl ether to extract indium and concentrate impurities. The reagents used in this method are not commonly used chemicals in the semiconductor industry and need to be distilled and purified by the laboratory itself. The operation is difficult to prevent the influence of reagent contamination, and different impurity elements need to be handled in different ways. In addition, the determination range of impurity aluminum in this method is 0.1-2μg / g, which cannot meet the detection needs of high-purity indium with lower aluminum content.
[0008] Therefore, it is crucial to establish a method that is easy to use for rapid detection of impurity element aluminum in high-purity indium, which also has important guiding significance for the production and trade settlement of high-purity indium. Summary of the invention
[0009] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method for detecting impurity aluminum in high-purity indium. The method has a simple sample processing process, convenient operation, fast analysis speed, can be used for large-scale sample detection, and the detection results are reliable and the detection limit is low. Most laboratories can implement it, which is conducive to the production and trade settlement of high-purity indium.
[0010] In order to achieve the above object, a first aspect of the present invention is to provide a method for detecting impurity aluminum in high-purity indium, the method comprising:
[0011] (1) dissolving high-purity indium in concentrated nitric acid to obtain solution I;
[0012] (2) subjecting solution I to a precipitation reaction with hydrofluoric acid and then performing solid-liquid separation;
[0013] (3) Heat the filtrate until it is nearly dry, then make up to volume with water and test the aluminum content using an inductively coupled plasma mass spectrometer.
[0014] The innovation of the present invention is that concentrated nitric acid is first used to dissolve high-purity indium, and then hydrofluoric acid is used to precipitate the indium element. After solid-liquid separation, a filtrate is taken, and at this time, the filtrate contains only a small amount of indium element, thereby eliminating the interference of the indium element. The filtrate is then heated, and after water is added to make the volume constant, an inductively coupled plasma mass spectrometer is used to accurately test the content of impurity aluminum in the high-purity indium, and the detection limit of the test method is low.
[0015] It should be noted that, in the present invention, nearly dry means 0.01 mL ≤ liquid volume ≤ 0.5 mL.
[0016] In a preferred embodiment, the container materials used for the dissolution, the precipitation reaction, the solid-liquid separation and the heating operation are independently selected from at least one of polytetrafluoroethylene, fusible polytetrafluoroethylene, polytrifluoroethylene-ethylene copolymer, fluororubber and polyetheretherketone.
[0017] In a preferred embodiment, an indium matrix and / or an internal standard substance is added during constant volume.
[0018] In a preferred embodiment, the concentrated nitric acid is selected from at least one of UPS grade nitric acid, EL grade nitric acid, UP grade nitric acid, UPSS grade nitric acid, UPSSS grade nitric acid, G1 grade nitric acid, G2 grade nitric acid, G3 grade nitric acid, G4 grade nitric acid and G5 grade nitric acid.
[0019] In a preferred embodiment, the hydrofluoric acid is selected from at least one of UPS grade hydrofluoric acid, EL grade hydrofluoric acid, UP grade hydrofluoric acid, UPSS grade hydrofluoric acid, UPSSS grade hydrofluoric acid, G1 grade hydrofluoric acid, G2 grade hydrofluoric acid, G3 grade hydrofluoric acid, G4 grade hydrofluoric acid and G5 grade hydrofluoric acid.
[0020] In a preferred solution, the solid-liquid ratio of the high-purity indium to the concentrated nitric acid is 1 g: 5-10 mL. The inventors found that under this preferred condition, the high-purity indium can be completely dissolved.
[0021] In a preferred embodiment, the dissolution time is ≥ 60 min.
[0022] In a preferred solution, the solid-liquid ratio of the high-purity indium to the hydrofluoric acid is 1 g: 2-5 mL. The inventors found that under this preferred condition, most of the indium can be precipitated.
[0023] In a preferred embodiment, the precipitation reaction time is ≥4h.
[0024] In a preferred embodiment, the heating temperature is 100-200° C. Under this preferred condition, the water in the solution can be removed and the container can be protected from damage.
[0025] In a preferred embodiment, the sampling volume of the filtrate is 4-10 mL.
[0026] In a preferred embodiment, the resistivity of the water should be no less than 18.2 MΩ·cm.
[0027] In a preferred embodiment, the purity of high-purity indium is not less than 99.999%.
[0028] In a preferred embodiment, when the purity of the indium matrix is above 7N, the indium content of the standard solution is 0.08-0.15wt%. When the purity of the indium matrix is above 7N, the impurity content is lower, and the addition of the indium matrix can eliminate the influence of the matrix.
[0029] Compared with the prior art, the present invention has at least the following advantages:
[0030] The sample pretreatment process of the present invention is simple, the required reagents of various purities are easy to obtain, the operation is convenient, the analysis speed is fast, the test results are reliable and the detection limit is low, most laboratories can implement it, and it can effectively guide the production and trade settlement of high-purity indium. At the same time, the method provided by the present invention is also applicable to the detection of other impurity elements in high-purity indium. DETAILED DESCRIPTION
[0031] The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.
[0032] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by professionals in this field without creative work still belong to the protection scope of the present invention.
[0033] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.
[0034] Example 1
[0035] The high-purity indium samples in this embodiment belong to the same batch. The high-purity indium samples of this batch were sent to a third-party laboratory for testing using the "YS / T 981.1-2014 High-purity Indium Chemical Analysis Method Magnesium, Aluminum, Silicon, Sulfur, Iron, Nickel, Copper, Zinc, Arsenic, Silver, Cadmium, Tin, Thallium, and Lead Determination High Mass Resolution Glow Discharge Mass Spectrometry" and the content of impurity element aluminum in the high-purity indium was measured to be 0.31 μg / g.
[0036] According to the industry standard "YS / T 981.2-2014 High-purity indium chemical analysis method for magnesium, aluminum, iron, nickel, copper, zinc, silver, cadmium, tin and lead determination inductively coupled plasma mass spectrometry", the impurity aluminum content in high-purity indium is determined:
[0037] Weigh 1.0568 grams of high-purity indium sample and place it in a 30ml quartz crucible. At the same time, perform a sample blank, wash with dilute hydrobromic acid (about 2mol / L), rinse with deionized water 5 times, add 5ml of 5mol / L hydrobromic acid, cover with a watch glass, heat in a dust cover (about 60°C) to dissolve, and cool to room temperature. Wash with 5ml of 5mol / L hydrobromic acid into a separatory funnel, add 20ml of isopropyl ether, shake for 2min, let stand and separate, transfer the aqueous phase into another separatory funnel, repeat the extraction once, let stand and separate, put the aqueous phase into a 15ml quartz crucible, heat and evaporate to dryness in a dust cover (temperature about 120°C), add 3 drops of aqua regia to dissolve the residue, and then transfer to a 10ml colorimetric tube with deionized water to make up the volume for measurement.
[0038] Aluminum standard solutions were prepared with concentrations of 0 μg / mL, 0.01 μg / mL, 0.02 μg / mL, 0.03 μg / mL, 0.04 μg / mL, and 0.05 μg / mL. The aluminum standard solutions all contained 1 μg / mL of rhodium. Using an inductively coupled plasma mass spectrometer and the internal standard curve method, the content of impurity element aluminum in high-purity indium was measured to be 0.30 μg / g.
[0039] Detection is performed according to the method provided by the present invention:
[0040] Weigh 1.0515 grams of high-purity indium sample and place it in a polytetrafluoroethylene container with a lid. At the same time, make a sample blank, add 7.5 ml of UPS-grade nitric acid, let it stand for 60 minutes until the sample is completely dissolved, then add 3 ml of UPS-grade hydrofluoric acid, cover the bottle tightly, and let it stand for 4 hours. Pour the supernatant into a polytetrafluoroethylene container, take 5 ml of the solution from the container into another polytetrafluoroethylene container, and then heat it on a low heat (temperature is 150°C) until it is almost dry, remove it, transfer it to a 50 ml volumetric flask with pure water, add 1.0 μg of rhodium standard solution, and shake it to volume.
[0041] The concentrations of aluminum standard solutions were prepared to be 0μg / mL, 0.001μg / mL, 0.005μg / mL, 0.01μg / mL, 0.02μg / mL, and 0.04μg / mL. The concentration of internal standard rhodium in the aluminum standard solution was the same as that of the test solution, and the concentration of matrix indium (purity of 7N) was 0.1wt%. The solution was fixed to volume and shaken with pure water. The content of impurity aluminum (mass number 27) was determined by the internal standard standard curve method on an inductively coupled plasma mass spectrometer, and the content of impurity element aluminum in high-purity indium was measured to be 0.32μg / g.
[0042] The result is consistent with the test results using the YS / T 981.2-2014 and YS / T 981.1-2014 methods, indicating that the detection method provided by the present invention is accurate and reliable.
[0043] Example 2
[0044] This example is carried out in a similar manner to Example 1, except that no indium matrix is added when preparing the standard curve, and the impurity aluminum in high-purity indium is tested by the external standard method. The content of impurity element aluminum in high-purity indium is measured to be 0.30 μg / g.
[0045] Example 3
[0046] The high-purity indium samples in this embodiment belong to the same batch. The high-purity indium samples of this batch were sent to a third-party laboratory for testing using the "YS / T 981.1-2014 High-purity Indium Chemical Analysis Method Magnesium, Aluminum, Silicon, Sulfur, Iron, Nickel, Copper, Zinc, Arsenic, Silver, Cadmium, Tin, Thallium, and Lead Determination High Mass Resolution Glow Discharge Mass Spectrometry" and the content of impurity element aluminum in the high-purity indium was measured to be 0.006 μg / g.
[0047] According to the industry standard "YS / T 981.2-2014 High-purity indium chemical analysis method for magnesium, aluminum, iron, nickel, copper, zinc, silver, cadmium, tin and lead determination inductively coupled plasma mass spectrometry", the impurity aluminum content in high-purity indium is determined:
[0048] Weigh 1.0068 grams of high-purity indium sample and place it in a 30ml quartz crucible. At the same time, perform a sample blank, wash with dilute hydrobromic acid (about 2mol / L), rinse with deionized water 5 times, add 5ml of 5mol / L hydrobromic acid, cover with a watch glass, heat in a dust cover (about 60°C) to dissolve, and cool to room temperature. Wash with 5ml of 5mol / L hydrobromic acid into a separatory funnel, add 20ml of isopropyl ether, shake for 2min, let stand and separate, transfer the aqueous phase into another separatory funnel, repeat the extraction once, let stand and separate, put the aqueous phase into a 15ml quartz crucible, heat and evaporate to dryness in a dust cover (temperature about 120°C), add 3 drops of aqua regia to dissolve the residue, and then transfer to a 10ml colorimetric tube with deionized water to make up the volume for measurement.
[0049] The concentrations of the prepared aluminum standard solutions were 0 μg / mL, 0.01 μg / mL, 0.02 μg / mL, 0.03 μg / mL, 0.04 μg / mL, and 0.05 μg / mL. The aluminum standard solutions all contained 1 μg / mL of rhodium. Using an inductively coupled plasma mass spectrometer and the internal standard curve method, the content of impurity element aluminum in high-purity indium was measured to be undetectable.
[0050] Detection is performed according to the method provided by the present invention:
[0051] Weigh 4 portions of the high-purity indium samples of this batch and place them in 4 polytetrafluoroethylene containers with lids, with the mass accurate to 1.00g, add 7.5ml of UPS-grade nitric acid, let stand for 60 minutes until the sample is completely dissolved, then add 3ml of UPS-grade hydrofluoric acid, cover the bottle tightly, and let stand for 4 hours. Pour the supernatant into a polytetrafluoroethylene container, take 5ml of the solution from the container into another polytetrafluoroethylene container, and heat it on a low heat (temperature of 180℃) until it is almost dry, remove it, transfer it to a 50ml volumetric flask with pure water, add 1.0μg of rhodium standard solution, and shake it to volume.
[0052] The concentrations of aluminum standard solutions were prepared to be 0μg / mL, 0.001μg / mL, 0.005μg / mL, 0.01μg / mL, 0.02μg / mL, and 0.04μg / mL. The concentration of internal standard rhodium in the aluminum standard solution was the same as that of the test solution, and the concentration of matrix indium (purity of 7N) was 0.1wt%. The solution was fixed to volume and shaken with pure water. The content of impurity aluminum (mass number 27) was determined by the internal standard curve method on an inductively coupled plasma mass spectrometer, and the content of impurity element aluminum in high-purity indium was measured to be 0.005μg / g.
[0053] The biggest difference between Example 3 and Example 1 is that the aluminum impurity content in high-purity indium is lower. This result is consistent with the test result of YS / T981.1-2014, and is quite different from the ICP-MS result under the YS / T 981.2-2014 method. The reason is that the aluminum detection range specified in the YS / T 981.2-2014 method is 0.1 to 2 μg / g, and it is impossible to detect aluminum impurity elements with a lower content.
[0054] It can be seen from Examples 1 to 3 that high-purity indium is dissolved by nitric acid and most of the matrix is removed by hydrofluoric acid. A smaller constant volume can be used during the measurement, which is equivalent to concentrating the impurity elements. This method is feasible and the results are reliable.
[0055] Example 4 (Detection limit test)
[0056] Prepare the sample blank according to the whole process of sample testing, add 7.5ml UPS grade nitric acid, let it stand for 60 minutes until the sample is completely dissolved, then add 3ml UPS grade hydrofluoric acid, cover the bottle tightly, and let it stand for 4 hours. Pour the supernatant into a polytetrafluoroethylene container, take 5ml of the solution from the container into another polytetrafluoroethylene container, and heat it on a low heat (temperature is 150℃) until it is almost dry, remove it, transfer it to a 50ml volumetric flask with pure water, add 1.0μg rhodium standard solution, and shake it to volume.
[0057] The blank sample was tested 10 times, and the standard deviation of the CPS value (signal intensity) of the blank sample was σ=14.6.
[0058] The concentrations of aluminum standard solutions were prepared to be 0μg / mL, 0.001μg / mL, 0.005μg / mL, 0.01μg / mL, 0.02μg / mL, and 0.04μg / mL. The concentration of internal standard rhodium in the aluminum standard solution was the same as that of the test solution, and the concentration of matrix indium (purity of 7N) was 0.1wt%. The solution was fixed to volume with pure water and shaken. The standard curve of aluminum was measured on an inductively coupled plasma mass spectrometer, and the slope (sensitivity) of aluminum was S=296530.
[0059] The signal intensity of the detection limit is 3 times the standard deviation of the blank sample, LOD (signal intensity) = 3×σ.
[0060]
[0061] The detection limit of aluminum element in this method tested by the standard curve method is 0.0001μg / mL. When the sample is tested at a 10-fold dilution, the detection limit of aluminum element is 0.001μg / g.
[0062] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.
Claims
1. A method for detecting impurity aluminum in high-purity indium, characterized in that: The method includes: (1) dissolving high-purity indium in concentrated nitric acid to obtain solution I; (2) subjecting solution I to a precipitation reaction with hydrofluoric acid and then performing solid-liquid separation; (3) Heat the filtrate until it is nearly dry, then dilute to volume with water and test the aluminum content using an inductively coupled plasma mass spectrometer.
2. The method for detecting impurity aluminum in high-purity indium according to claim 1, characterized in that: The container materials used for the dissolution, the precipitation reaction, the solid-liquid separation and the heating operation are independently selected from at least one of polytetrafluoroethylene, fusible polytetrafluoroethylene, polytrifluoroethylene-ethylene copolymer, fluororubber and polyetheretherketone.
3. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The concentrated nitric acid is selected from at least one of UPS grade nitric acid, EL grade nitric acid, UP grade nitric acid, UPSS grade nitric acid, UPSSS grade nitric acid, G1 grade nitric acid, G2 grade nitric acid, G3 grade nitric acid, G4 grade nitric acid and G5 grade nitric acid.
4. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The hydrofluoric acid is selected from at least one of UPS grade hydrofluoric acid, EL grade hydrofluoric acid, UP grade hydrofluoric acid, UPSS grade hydrofluoric acid, UPSSS grade hydrofluoric acid, G1 grade hydrofluoric acid, G2 grade hydrofluoric acid, G3 grade hydrofluoric acid, G4 grade hydrofluoric acid and G5 grade hydrofluoric acid.
5. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The solid-liquid ratio of the high-purity indium to the concentrated nitric acid is 1 g: 5-10 mL.
6. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The solid-liquid ratio of the high-purity indium to the hydrofluoric acid is 1 g: 2-5 mL.
7. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The precipitation reaction time is ≥4h.
8. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The heating temperature is 100-200°C.
9. The method for detecting impurity aluminum in high-purity indium according to claim 1 or 2, characterized in that: The sampling volume of the filtrate is 4-10 mL.