Method and device for detecting impurity zinc in high-purity gallium

Abstract

The application discloses a method and device for detecting impurity element zinc in high-purity gallium. The detection method comprises the following steps: taking a mixed centrifugal extraction tube, adding a high-purity gallium sample, adding a solution containing a high-purity extractant, sealing the mixed centrifugal extraction tube, fixing the mixed centrifugal extraction tube horizontally on a mixed oscillation extractor, performing oscillation extraction, taking out the mixed centrifugal extraction tube, vertically storing the mixed centrifugal extraction tube, making liquid gallium gather at the conical bottom of the mixed centrifugal extraction tube, separating the extraction liquid, and using internal standard calibration ICP-MS to detect the impurity zinc content. The volume concentration of the high-purity extractant in the solution containing the high-purity extractant is 1-10%, and the high-purity extractant is selected from one of hydrochloric acid, nitric acid and sulfuric acid. The detection method provided by the application has the advantages of simple process, short flow, easy operation, fast extraction and separation speed, clean matrix removal, complete impurity retention and good reproducibility.

Description

Technical Field

[0001] This invention relates to a method and apparatus for detecting zinc impurities in high-purity gallium, belonging to the field of high-purity material analysis. Background Technology

[0002] High-purity gallium is a primary material for manufacturing semiconductors such as gallium arsenide and gallium phosphide. Pure gallium and its low-melting-point alloys can be used as heat exchange media in nuclear reactions and as fillers in high-temperature thermometers. The content of impurity elements in high-purity gallium plays a crucial role in the performance of these high-purity materials.

[0003] Currently, impurity elements in high-purity gallium are mainly detected using instruments such as ICP-OES, ICP-MS, and GD-MS. However, ICP-OES has low sensitivity and is ineffective for high-purity gallium, especially for gallium with a purity of 6N or higher. GD-MS is expensive, has limited equipment availability, and high analysis costs, making it unsuitable for production control needs. In contrast, ICP-MS, with its high sensitivity and moderate analysis cost, meets the needs of most production and trading users and is gaining increasing attention.

[0004] However, ICP-MS is not resistant to high-matrix samples. Therefore, some method must be used to remove the matrix, leaving only impurity elements for ICP-MS analysis. In the traditional detection method of separating high-purity gallium matrices using chlorination, it was found that the impurity element zinc can also volatilize along with the matrix, resulting in significant loss. Therefore, using chlorination to separate the matrix and determine zinc impurity in high-purity gallium is inaccurate, and a new method for zinc detection needs to be explored to supplement and improve this approach. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for detecting zinc, an impurity element, in high-purity gallium. This method utilizes the difference in electrode potential between the matrix gallium and the impurity zinc. In a specific solution, the impurity zinc is extracted into the solution, while the matrix gallium remains in a metallic state, and is then determined using ICP-MS. The solution provided by this invention is simple to operate, fast in analysis, allows for the weighing of large-mass samples to increase the enrichment factor, and provides accurate detection results, meeting the rapid detection requirements of high-purity gallium production lines.

[0006] The second objective of this invention is to provide a device for detecting zinc, an impurity element, in high-purity gallium.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention discloses a method for detecting zinc, an impurity element, in high-purity gallium. The method involves taking a mixed centrifugal extraction tube, adding a high-purity gallium sample, then adding a solution containing a high-purity extractant. The mixed centrifugal extraction tube is sealed and fixed horizontally on a mixed oscillating extractor for oscillating extraction. The mixed centrifugal extraction tube is then removed and stored upright, allowing the liquid gallium to collect at the bottom of the cone and separate from the extract. The extract is then used to determine the zinc impurity content using an internal standard-calibrated ICP-MS. The high-purity extractant solution has a volume concentration of 1–10%, preferably 1–3%, and the high-purity extractant is selected from hydrochloric acid, nitric acid, and sulfuric acid.

[0009] This invention employs an inorganic acid extractant, in which gallium has very low solubility at room temperature, while zinc is highly soluble. Because zinc has a more negative electrode potential than gallium, trace amounts of zinc impurities dissolve and accumulate in the high-purity extractant from the high-purity gallium. The zinc impurity in the high-purity extractant is less than 0.1 ppb. This invention utilizes a mixed centrifugal extraction tube placed horizontally on a mixed oscillating extractor, where the gallium is dispersed into small particles in the extractant through oscillation, thus successfully extracting the zinc impurity.

[0010] In this invention, high-purity gallium refers to gallium with a purity of 6N or higher.

[0011] In a preferred embodiment, the capacity of the mixing centrifugal extraction tube is 20-30 ml, the amount of high-purity gallium sample added is 1-3 g, and the amount of solution containing high-purity extractant added is 10-20 ml.

[0012] In this invention, the centrifugal extraction tube is horizontally positioned during extraction. It can be seen that the volume of the solution containing high-purity extractant added is only about two-thirds of the volume of the extraction tube. When the mixture is shaken and extracted, the extract repeatedly collides with the wall of the centrifugal extraction tube, resulting in a better extraction effect.

[0013] In a preferred embodiment, the mixing centrifugal extraction tube is made of an inert material, preferably polytetrafluoroethylene (PTFE). The selected material has high purity, is easy to process, and allows for good sealing between materials.

[0014] In a preferred embodiment, the inner wall of the mixing centrifugal extraction tube contains a toothed structure.

[0015] The inventors discovered that irregular teeth on the inner wall of the mixing centrifugal extraction tube can disperse gallium energy without agglomeration, allowing it to mix fully with the extraction liquid and resulting in better extraction.

[0016] In a preferred embodiment, the bottom of the mixing centrifugal extraction tube is conical.

[0017] The inventors discovered that the bottom of the mixing centrifugal extraction tube is designed as a cone. When the mixing and oscillating extraction tube is upright, the liquid gallium quickly gathers at the bottom of the cone, realizing the rapid separation of the extract and the liquid gallium, which makes it convenient to remove the extract.

[0018] In a preferred embodiment, the high-purity gallium sample is first heated to melt, and then added to a mixing centrifugal extraction tube.

[0019] The high-purity gallium sample was first melted in a water bath. Because gallium has a low melting point of only 29°C, it is prone to crystallization and solidification. During the crystallization and solidification process, impurities may be unevenly distributed. Therefore, the sample must be melted and mixed before weighing to avoid unrepresentative sampling.

[0020] In a preferred embodiment, the solution containing the high-purity extractant contains an internal standard for ICP-MS.

[0021] The high-purity extractant contains an internal standard for ICP-MS, typically Rh103. The internal standard serves to eliminate the influence of the gallium matrix on the measurement and ensure the accuracy of the results.

[0022] In the actual operation, a blank test should also be prepared.

[0023] In a preferred embodiment, during the oscillation extraction, the oscillation speed is 800–2500 rpm, preferably 1200–1800 rpm, and the time is 2–20 minutes.

[0024] The inventors discovered that at the aforementioned speed, liquid gallium can be dispersed into gallium beads smaller than 0.1 mm during the oscillation process, thereby achieving successful extraction of impurities. Therefore, the oscillation speed during extraction needs to be effectively controlled. If the speed is too slow, gallium cannot be dispersed into small particles in the extractant, and the impurity extraction rate will not meet the requirements. If the oscillation speed is too high, the friction between gallium and the surface of the extractant will be too intense, causing an oxide film to form on the surface of the gallium metal, resulting in extraction failure.

[0025] The present invention also provides a device for detecting zinc impurities in high-purity gallium, comprising a mixing centrifugal extraction tube and a mixing oscillating extractor, wherein the mixing centrifugal extraction tube consists of a tube body with a conical bottom and a threaded cap, and the mixing oscillating extractor consists of a power switch, a mixing oscillating extraction tube, a speed regulator, and a time regulator.

[0026] In a preferred embodiment, the mixing centrifugal extraction tube is made of an inert material, preferably polytetrafluoroethylene (PTFE).

[0027] In a preferred embodiment, the inner wall of the mixing centrifugal extraction tube contains a toothed structure.

[0028] The main function of the mixing and shaking extractor is to mix and shake the sample, allowing the zinc in gallium to be extracted and dissolved into the solution. The speed regulator allows for free adjustment of the shaking speed, and the time regulator allows for free adjustment of the shaking time. The mixing centrifuge extraction tube and the mixing and shaking extractor are connected by a module made of pearl cotton. The pore size is adapted to the size of the mixing centrifuge extraction tube, ensuring a tight fixation to prevent it from falling off during shaking. Other fixation methods can also be used.

[0029] Principles and advantages

[0030] This invention employs an inorganic acid extractant, in which gallium has very low solubility at room temperature, while zinc is highly soluble. Because zinc has a more negative electrode potential than gallium, trace zinc impurities dissolve and accumulate in the high-purity extractant from the high-purity gallium. The zinc impurity in the high-purity extractant is less than 0.1 ppb. This invention utilizes a mixed centrifugal extraction tube placed horizontally on a mixed oscillating extractor. The gallium is dispersed into small particles in the extractant through oscillation, thus successfully extracting the zinc impurity, while the gallium matrix remains in its metallic state. ICP-MS analysis is then performed.

[0031] Compared with existing technologies, the beneficial effects of the technical solution of this invention are as follows:

[0032] 1) The detection device provided by this invention is easy to operate, saves manpower, and improves work efficiency; the operating conditions are consistent, avoiding differences in extraction due to manual operation; the analysis speed is fast, and large mass samples can be weighed, reducing sample errors; the detection results are accurate, meeting the needs of rapid detection on high-purity gallium production lines.

[0033] 2) The detection method provided by the present invention is simple, has a short process, is easy to operate, has a fast extraction and separation speed, removes the matrix cleanly, retains impurities completely, and has good reproducibility. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the mixing centrifugal extraction tube of the present invention.

[0035] The components are: 1. cap; 2. thread; 3. tube body; 4. conical bottom.

[0036] Figure 2 This is a schematic diagram of the mixing and shaking extractor of the present invention.

[0037] The components include: 5. Mixing and shaking extractor; 6. Power switch; 7. Mixing and centrifugal extraction tube; 8. Speed ​​regulator; 9. Time regulator. Detailed Implementation

[0038] As attached Figure 1 and 2As shown, the present invention provides a device for detecting zinc impurities in high-purity gallium, including a mixing centrifugal extraction tube and a mixing oscillating extractor. The mixing centrifugal extraction tube consists of a tube body 3 with a conical bottom 4 and a cap 1 with threads 2. The mixing oscillating extractor consists of a power switch 6, a speed regulator 8, and a time regulator 9.

[0039] The material of the mixing centrifugal extraction tube is an inert material, preferably polytetrafluoroethylene.

[0040] The inner wall of the mixing centrifugal extraction tube has a toothed structure.

[0041] The main function of the mixing and shaking extractor is to mix and shake the sample, allowing the zinc in gallium to be extracted and dissolved into the solution. The speed regulator allows for free adjustment of the shaking speed, and the time regulator allows for free adjustment of the shaking time. The mixing centrifuge extraction tube and the mixing and shaking extractor are connected by a module made of pearl cotton. The pore size is adapted to the size of the mixing centrifuge extraction tube, ensuring a tight fixation to prevent it from falling off during shaking. Other fixation methods can also be used.

[0042] The method for detecting zinc impurities in high-purity gallium provided in the following embodiments uses the above-mentioned apparatus.

[0043] Example 1

[0044] A batch of samples was melted in a water bath. 1.0025 g of high-purity gallium was weighed into a clean polytetrafluoroethylene mixed centrifugal extraction tube, and 10.0 mL of 2% hydrochloric acid was added. The extract was pre-mixed with 2 ppbRh internal standard. A blank test was also performed.

[0045] Place the mixing centrifugal extraction tube horizontally on the mixing and shaking extractor and fix it in place;

[0046] Start the mixing and shaking extractor, set the speed to 1500 RMP, and the time to 10 min.

[0047] After the mixing and oscillating extraction is complete, the mixing centrifuge extraction tube is removed and stored upright, allowing the liquid gallium to collect at the bottom of the cone of the mixing centrifuge extraction tube and separate from the extract. The zinc content of the extract is determined by ICP-MS with internal standard calibration.

[0048] Meanwhile, a portion of the extract was subjected to ICP-OES to determine the gallium content.

[0049] ICP-OES analysis showed that the gallium content in the extract was 32.3 ppm, which is less than the 0.1% ICP-MS matrix concentration.

[0050] ICP-MS analysis showed that the zinc content in the high-purity gallium was 0.008 ppm, meeting the 6N high-purity gallium standard.

[0051] Example 2

[0052] For water bath melting of the same batch of samples as in Example 1, weigh 1.0005 g and 1.0003 g of high-purity gallium into two clean polytetrafluoroethylene mixed centrifugal extraction tubes. Add 10 ppb of zinc standard solution to one of the mixed centrifugal extraction tubes, and then add 10.0 mL of 2% hydrochloric acid. The extract was pre-mixed with 2 ppb Rh internal standard. A blank test was also performed.

[0053] Place the mixing centrifugal extraction tube horizontally on the mixing and shaking extractor and fix it in place;

[0054] Start the mixing and shaking extractor, set the speed to 1500 RMP, and the time to 10 min.

[0055] After the mixing and oscillating extraction is complete, the mixing centrifuge extraction tube is removed and stored upright, allowing the liquid gallium to collect at the bottom of the cone of the mixing centrifuge extraction tube and separate from the extract. The zinc content of the extract is determined by ICP-MS with internal standard calibration.

[0056] Meanwhile, a portion of the extract was subjected to ICP-OES to determine the gallium content.

[0057] ICP-OES analysis showed that the gallium content in the extract was 31.6 ppm, which is less than the 0.1% ICP-MS matrix concentration.

[0058] ICP-MS analysis showed that the zinc content in high-purity gallium was 0.008 ppm, and spiked analysis showed that the zinc content was 0.0177 ppm, resulting in a standard recovery rate of 97%. The spiked recovery rate indicates that the detection results are reliable and accurate.

[0059] The batch of high-purity gallium samples was sent to a third-party testing institution for GD-MS analysis, and the zinc content was found to be 0.007 ppm, which also verified that the testing method was correct.

[0060] Comparative Example 1

[0061] For water bath melting of the same batch of samples as in Example 1, 1.0042 g of high-purity gallium was weighed into a clean polytetrafluoroethylene mixed centrifugal extraction tube, and 10.0 mL of hydrochloric acid with a volume concentration of 2% was added. The extraction solution was pre-mixed with 2 ppbRh internal standard, and a blank test was performed simultaneously.

[0062] Place the mixing centrifugal extraction tube horizontally on the mixing and shaking extractor and fix it in place;

[0063] Start the mixing and shaking extractor, set the speed to 500 RMP, and the time to 10 min.

[0064] After the mixing and oscillating extraction is complete, the mixing centrifuge extraction tube is removed and stored upright, allowing the liquid gallium to collect at the bottom of the cone of the mixing centrifuge extraction tube and separate from the extract. The zinc content of the extract is determined by ICP-MS with internal standard calibration.

[0065] Meanwhile, a portion of the extract was subjected to ICP-OES to determine the gallium content.

[0066] ICP-OES analysis showed that the gallium content in the extract was 29.5 ppm, which is less than the 0.1% ICP-MS matrix concentration.

[0067] ICP-MS analysis showed that the zinc content in high-purity gallium was 0.005 ppm.

[0068] Compared to Example 1, the comparative example only changed the speed of the mixing oscillating extractor, while keeping all other conditions the same. This speed was reduced to 500 RMP, below the minimum limit of 800 RMP, resulting in lower detection results than in Example 1. The main reason was the reduced speed, leading to insufficient extraction and incomplete extraction of the zinc impurity.

Claims

1. A method for determining zinc, an impurity element, in high-purity gallium, characterized in that: Take a mixed centrifugal extraction tube, add a high-purity gallium sample, then add a solution containing a high-purity extractant, seal the mixed centrifugal extraction tube, fix the mixed centrifugal extraction tube horizontally on a mixed oscillating extractor, and perform oscillating extraction. Remove the mixed centrifugal extraction tube and store it upright, allowing the liquid gallium to collect at the bottom of the cone of the mixed centrifugal extraction tube and separate from the extract. Take the extract and determine the zinc impurity content using an internal standard calibrated ICP-MS. The volume concentration of the high-purity extractant in the solution is 1-10%, and the high-purity extractant is selected from hydrochloric acid, nitric acid, and sulfuric acid.

2. The method for determining zinc, an impurity element in high-purity gallium, according to claim 1, is characterized in that: The capacity of the mixed centrifugal extraction tube is 20-30 ml, the amount of high-purity gallium sample added is 1-3 g, and the amount of solution containing high-purity extractant added is 10-20 ml.

3. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: The mixing centrifugal extraction tube is made of an inert material.

4. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: The inner wall of the mixing centrifugal extraction tube has a toothed structure.

5. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: The bottom of the mixing centrifugal extraction tube is conical.

6. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: The high-purity gallium sample is first heated to melt, and then added to a mixing centrifugal extraction tube.

7. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: The solution containing the high-purity extractant contains an internal standard for ICP-MS.

8. A method for determining zinc, an impurity element, in high-purity gallium according to claim 1 or 2, characterized in that: During the oscillation extraction, the oscillation speed is 800~2500 rpm, and the time is 2~20 minutes.

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