A method for determining ultra-low carbon and sulfur content in high-purity nickel.
By preparing standard samples compatible with high-purity nickel matrix and using sucrose and sulfate standard solutions as reference reagents, the detection range was expanded, the problem of accurate determination of ultra-low carbon and sulfur content in high-purity nickel was solved, and the accurate determination and traceability detection of ultra-low carbon and sulfur content in high-purity nickel were realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JINCHUAN GROUP CO LTD
- Filing Date
- 2025-10-28
- Publication Date
- 2026-05-26
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal composition analysis technology, specifically relating to a method for determining the ultra-low carbon and sulfur content in high-purity nickel. Background Technology
[0002] Nickel, as an important non-ferrous metal, is widely used in civilian fields such as stainless steel, electroplating, batteries, and chemicals, as well as high-end fields such as aerospace, missiles, and semiconductors, thanks to its good mechanical strength, ductility, and chemical stability. Among them, high-purity nickel, due to its high purity and low impurity content, has become a key raw material for high-tech industries such as semiconductor chip manufacturing.
[0003] Carbon and sulfur are key gaseous impurities affecting the performance of high-purity nickel. Carbon content directly alters the mechanical properties of nickel: increasing carbon content improves hardness and strength but decreases toughness and ductility; conversely, decreasing carbon content has the opposite effect. Sulfur, as a harmful element, can cause nickel alloys to crack during high-temperature, high-pressure processing, severely impacting product quality. Therefore, accurately determining the carbon and sulfur content in high-purity nickel is a crucial step in controlling product quality.
[0004] Currently, relevant national standards such as GB / T 26016-2021 "High Purity Nickel" and GB / T 6516-2010 "Electrolytic Nickel" only specify the upper limits of carbon and sulfur content in high-purity nickel (e.g., minimum carbon standard of 0.005% and minimum sulfur standard of 0.001%), but do not provide corresponding testing methods. The existing national standard for nickel carbon and sulfur testing, GB8647-2006 "Chemical Analysis Methods for Nickel," is only applicable to the detection of carbon and sulfur content >0.005%, and cannot meet the testing requirements for ultra-low content (<0.005%) in high-purity nickel.
[0005] Infrared absorption is a commonly used technique for gaseous element detection, offering advantages such as ease of operation and rapid analysis. However, in the detection of high-purity nickel, this method faces two major challenges: First, there is a lack of carbon and sulfur standard samples on the market that are consistent with the high-purity nickel matrix and have matching content. Existing detection methods often use standard samples with different matrices such as steel and titanium alloys as substitutes. Due to the differences in melting temperatures of different matrices, the release of carbon and sulfur varies, severely affecting the accuracy of detection. Second, the detection range of existing standard curves mostly begins at 0.005%, failing to cover the ultra-low content range in high-purity nickel, resulting in poor traceability of detection results.
[0006] To address the aforementioned issues, this invention proposes a detection method based on reference reagents. By preparing standard samples compatible with a high-purity nickel matrix, the range of the standard curve is extended, enabling accurate determination of ultra-low carbon and sulfur content while ensuring the traceability of the detection results. Summary of the Invention
[0007] The purpose of this invention is to provide an accurate, rapid, traceable and easy-to-operate method for determining the ultra-low carbon and sulfur content in high-purity nickel, solving the problems of mismatched standard sample matrix, insufficient detection range and poor traceability of results in existing detection methods.
[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for determining the ultra-low carbon and sulfur content in high-purity nickel includes the following steps: Step 1: Place the block, granular or shaving high-purity nickel sample obtained from the cutting preparation into a 100mL glass container, add acetone and sonicate for 1-10 minutes, discard the organic reagents and rinse with pure water, then add inorganic acid to a 100mL glass container, soak, discard the acid washing solution and rinse with pure water. Step 2: Choose to air dry or use a hair dryer to dry the sample until the surface moisture is dry; Step 3: Pre-treat the ceramic crucible: calcine at 900℃ for 1-3 hours or at 1250℃ for 0.5-1 hour; Step 4: After ignition, allow the crucible to cool naturally to near room temperature and then transfer it to a desiccator for storage. Step 5: Using sucrose as a carbon reference reagent and sulfate standard solution as a sulfur reference reagent, the sucrose is solid and the sulfate standard solution has a concentration of 1000 ug / mL, a solution of a certain concentration is prepared; different volumes of the solution are quantitatively transferred into nickel bags and slowly dried in an oven at 80℃ to prepare a series of carbon and sulfur standard points; Step 6: Prepare carbon and sulfur standard curve 1: Weigh 0.1000g~1.000g of solid standard sample with carbon and sulfur content equivalent to that in high-purity nickel sample, place it in a calcined ceramic crucible, add flux in a certain proportion for determination, calibrate the carbon and sulfur working curve, and test the prepared reference reagent carbon and sulfur standard sample. Step 7, Preparation of carbon and sulfur standard curve 2: Prepare carbon and sulfur standard solutions of a certain concentration using reference reagents and standard solutions containing carbon and sulfur elements, quantitatively transfer a series of standard points into a nickel bag, slowly dry in an oven at 80℃, add pure iron and pure tungsten flux in a certain proportion, perform the determination, calibrate the carbon and sulfur working curve, and test the solid standard sample. Step 8: Place the crucible on the crucible holder of the carbon-sulfur analyzer and perform sample testing according to the sample analysis procedure; Step 9: Prepare a blank test according to the operating procedures described in steps 1 to 8; Step 10: Weigh the sample to be tested as described in Step 1, and test it according to the sample detection program of the carbon and sulfur analyzer to determine the carbon and sulfur content in the sample. Step 11: Calculate the ultra-low carbon and sulfur content in high-purity nickel using the formula below, and retain two significant figures in the result. In the formula: wc is the mass fraction of carbon or sulfur, in %; mt is the mass of carbon and sulfur in the sample, in g; m0 is the mass of carbon and sulfur in the blank sample, in g; c is the mass compensation parameter; and m is the mass of the sample, in g.
[0009] Preferably, the organic reagent in step 1 is acetone, the ultrasonic treatment time is 1 to 10 minutes, the inorganic acid is hydrochloric acid, the ratio of hydrochloric acid added to the glass container is 1:1 to 1:9, and the soaking time is 1 to 10 minutes.
[0010] Preferably, the concentration of the reference reagent and standard solution in step 5 is configured to be 10 ug / mL to 100 ug / mL.
[0011] Preferably, in step 6, the solid standard sample is selected from nickel and nickel alloy matrix or cobalt matrix.
[0012] Preferably, the flux in steps 6 and 7 is a combination of two fluxes selected from pure iron, pure tungsten, and pure tin.
[0013] Preferably, in step 6, solid standard samples are used to calibrate the carbon and sulfur working curves.
[0014] Preferably, in step 7, the carbon and sulfur working curves are calibrated using standard points prepared with reference reagents or standard solutions.
[0015] Preferably, when the two selected fluxes are pure iron and pure tungsten, the amounts used are 0.5000 g and 1.5000 g, respectively; when the two selected fluxes are pure iron and pure tin, the amounts used are 1.5000 g and 0.2000 g, respectively; and when the two selected fluxes are pure tungsten and pure tin, the amounts used are 1.5000 g and 0.2000 g, respectively.
[0016] Preferably, in step 9, the average carbon blank value is less than 0.0003% and the average sulfur blank value is less than 0.0001%.
[0017] Preferably, the sample weight of the high-purity nickel to be tested in step 10 is in the range of 0.1000 g to 1.000 g.
[0018] The beneficial effects of this invention are as follows: 1. This invention uses acetone as an organic cleaning agent to effectively remove organic contaminants during sample preparation. After cleaning with organic reagents, hydrochloric acid is used to clean the sample, removing oxidation residues and acetone residues from the sample surface. This minimizes the impact of sample contamination on carbon and sulfur, and improves the accuracy and precision of the method.
[0019] 2. This invention uses reference reagents to prepare carbon and sulfur standard samples, eliminating the release error caused by the inconsistency of the solid standard sample matrix and improving the accuracy of the method.
[0020] 3. This invention uses reference reagents to prepare carbon and sulfur standard samples, eliminating the detection error caused by the mismatch of carbon and sulfur content between the solid standard sample and the high-purity nickel sample to be tested, and improving the accuracy of the method.
[0021] 4. This invention uses reference reagents to prepare carbon and sulfur standard samples, extending the standard curve to 1 ppm and expanding the detection range of the detection method from 50 ppm to 1 ppm, thus broadening the detection range and the applicability of the method.
[0022] 5. This invention uses reference reagents to prepare carbon and sulfur standard samples, verifies consistency with solid standard samples, ensures traceability of test results, and improves the accuracy of the method.
[0023] 6. This invention uses a reference reagent method based on infrared absorption, and the equipment is inexpensive, easy to operate and master, and has a wider range of applications in laboratories.
[0024] 7. The method of this invention is simple, fast, and has no health hazards. It is suitable for the analysis of large batches of samples in production and also provides a reference for the determination of ultra-low carbon and sulfur in cobalt and other metal materials where other standard samples are lacking. Detailed Implementation
[0025] The present invention will be further described below with reference to specific embodiments: Technical solution: A method for determining the ultra-low carbon and sulfur content in high-purity nickel includes the following steps: Step 1: Place the high-purity nickel sample in a 100mL glass container, add the organic reagent acetone, and ultrasonically clean for 3~10min; The sample shape is preferably a round rod with a diameter of Ф3 mm to Ф5 mm or a square rod with a cross-section of 3 mm × 3 mm to 5 mm × 5 mm. It can also be in the form of debris, and the surface should be smooth. Clean the organic reagents off the sample surface with pure water, soak in 1:9 hydrochloric acid for 1-3 minutes, rinse off any hydrochloric acid residue on the sample surface with pure water, and then soak the sample in anhydrous ethanol. Before use, remove the sample with tweezers and let it air dry. Step 2, Ceramic crucible calcination: The crucible is 25 mm * 25 mm in size. It is placed in a high-temperature furnace and calcined at 900℃ for 1-2 hours, or at 1250℃ for 0.5-1 hour. Choose one of the two temperatures, and after cooling, place it in a desiccator for later use.
[0026] Step 3: Creating the Standard Curve The calibration method using primary standard reagents and the calibration method using solid standard samples are used for mutual verification. After calibrating the curve using primary standard reagents, the accuracy of the method is assessed by measuring solid standard samples; conversely, the accuracy of the method is assessed by testing primary standard reagents after calibrating the curve using certified solid standard samples. The primary standard method uses sucrose (a national first-class standard substance) and sulfate standard solution to prepare a series of carbon and sulfur standard sample points. The carbon content standard curve range is 0.0005%~0.005%, and the sulfur content standard curve range is 0.0001%~0.002%. The method for preparing the sucrose and sulfate standard series using the primary standard method is to transfer sucrose standard solution (100 ug / mL) and sulfate standard solution (10 ug / mL) into 6 nickel capsules according to Table 1, and dry them at 80 ℃ for later use.
[0027] Specific preparation method: Weigh 0.0238 g of sucrose into a 200 mL beaker, add 50 mL of water (grade II or higher) to dissolve, transfer to a 100 mL volumetric flask, dilute to the mark with water, and mix well. This solution contains 100 ug / mL of carbon. Transfer 3.00 mL of sulfate standard solution (1000 ug / mL) into a 100 mL volumetric flask, dilute to the mark with water, and mix well. This solution contains 10 ug / mL of sulfur. Transfer 0 mL, 0.025 mL, 0.05 mL, 0.10 mL, 0.20 mL, and 0.25 mL of sucrose standard solution (100 μg / mL) and 0 mL, 0.05 mL, 0.25 mL, 0.50 mL, 0.75 mL, and 1.00 mL of sulfate standard solution (10 μg / mL) to six nickel flasks, respectively, and dry them at 80 °C for later use. The carbon content of this curve is 0%, 0.0005%, 0.0010%, 0.0020%, 0.0040%, and 0.0050%, respectively, and the sulfur content is 0%, 0.0001%, 0.0005%, 0.0010%, 0.0015%, and 0.0020%, respectively. The solid standard sample used is a nickel alloy standard sample (national first-class standard material), with a carbon content of 0.0015% and a sulfur content of 0.0024%.
[0028] Step 4: Weigh out the nickel sac, 0.25 g to 1.50 g of pure iron, and 0.25 g to 1.50 g of tungsten granules and add them to the calcined crucible. Perform blank testing according to the equipment instructions. Perform at least three parallel tests to examine the system blank and ensure that the carbon blank value is less than 0.0003% and the sulfur content blank value is less than 0.0001%.
[0029] Step 5: Place the above-mentioned reference reagent series points into the ignited ceramic crucibles, add 0.5 g of pure iron flux and 1.5 g of pure tungsten flux, and perform the determination on the carbon-sulfur analyzer according to the equipment operation manual. Plot the standard curve, and measure the solid nickel standard sample and the treated high-purity nickel sample under this standard curve to ensure that the measurement results of the solid standard sample are within the uncertainty range of the standard sample.
[0030] Step 6: Place the above-mentioned solid nickel standard samples into nickel bags, place them into ignited ceramic crucibles, add 0.5 g of pure iron flux and 1.5 g of pure tungsten flux, and perform the determination on a carbon-sulfur analyzer according to the equipment operation manual. Plot a standard curve on the carbon-sulfur analyzer, and determine the reference reagent standard series samples and the treated high-purity nickel samples under this standard curve.
[0031] Step 7: Calculate the carbon and sulfur content in high-purity nickel using the formula below, and keep two significant figures in the result. Where: m t m0 represents the mass of carbon and sulfur in the sample, in g; C represents the mass of carbon and sulfur in the blank sample, in g; m represents the mass compensation parameter; m represents the mass of the sample, in g; and 100 represents the percentage conversion rate.
[0032] Example 1 High-purity nickel sample-1#: The main nickel content of the sample is 99.9999%. 1. Instruments and equipment used in the experiment: Carbon and sulfur analyzer, COREY600 High-temperature muffle furnace, SXW-8-17 Ultrasonic cleaner, KQ-500B 2. Reagents used in the experiment: 2.1 Secondary pure water 2.2 36%~38% concentrated hydrochloric acid (superior grade, ρ=1.19g / cm3) 2.3 Acetone, superior grade 2.4 Oxygen (99.995%) 2.5 Nitrogen (99.95%) 2.6 Sucrose Standard Material: Sucrose (GBW10067) 2.7 Sulfate standard solution (GSB 04-1773-2004, 1000 ug / mL) The concentrations of the carbon and sulfur standard solutions prepared in this invention are as follows: C: 100.00 ug / mL; S: 10 ug / mL 3. Operating conditions of the carbon-sulfur analyzer: Analysis power: 3.5 W; Analysis time: 50 s.
[0033] 4. Test Procedure The crucible measures 25 mm x 25 mm and is placed in a high-temperature furnace for heating. Heating at 900°C for 1–2 hours, or at 1250°C for 0.5–1 hour, is performed. After cooling, the crucible is placed in a desiccator for later use.
[0034] The best preparation of high-purity nickel samples is in the form of round rods with a diameter of Ф3 mm to Ф5 mm or square rods with a cross-section of 3 mm × 3 mm to 5 mm × 5 mm. They can also be in the form of fragments, but the surface must be smooth. Place the high-purity nickel sample in a 200 mL glass container, add the organic reagent acetone, and ultrasonically clean for 3–10 min.
[0035] Clean the organic reagents off the sample surface with pure water, soak it in 1:9 hydrochloric acid for 1-3 minutes, rinse the sample surface with pure water to remove any hydrochloric acid residue, and then soak the sample in anhydrous ethanol. Before use, remove the sample with tweezers and let it air dry.
[0036] Add nickel, 0.25 g to 1.50 g of pure iron, and 0.25 g to 1.50 g of tungsten granules to the calcined crucible and perform blank testing according to the equipment instructions. Perform at least three parallel tests to examine the system blank and ensure that the carbon blank value is less than 0.0003% and the sulfur content blank value is less than 0.0001%.
[0037] The reference reagent series points were placed in the ignited ceramic crucible, and 0.5 g of pure iron flux and 1.5 g of pure tungsten flux were added. The measurements were performed on the carbon-sulfur analyzer according to the equipment operation manual, and a standard curve was plotted. The solid nickel standard sample and the treated high-purity nickel sample were measured under this standard curve to ensure that the measurement results of the solid standard sample were within the uncertainty range of the standard sample.
[0038] Solid nickel standard samples were placed in ignited ceramic crucibles, and nickel sacs, 0.5 g pure iron flux, and 1.5 g pure tungsten flux were added. The samples were measured on a carbon-sulfur analyzer according to the equipment operation manual. A standard curve was plotted on the carbon-sulfur analyzer. The reference reagent standard series samples and the treated high-purity nickel samples were measured under this standard curve.
[0039] The test results obtained after computer data processing are shown in Table 2.
[0040] Example 2 High-purity nickel sample-2#: The main nickel content of the sample is 99.9999%. 1. Instruments and equipment used in the experiment: Carbon and sulfur analyzer, COREY600 High-temperature muffle furnace, SXW-8-17 Ultrasonic cleaner, KQ-500B 2. Reagents used in the experiment: 2.1 Secondary pure water 2.2 36%~38% concentrated hydrochloric acid (superior grade, ρ=1.19g / cm3) 2.3 Acetone, superior grade 2.4 Oxygen (99.995%) 2.5 Nitrogen (99.95%) 2.6 Sucrose Standard Material: Sucrose (GBW10067) 2.7 Sulfate standard solution (GSB 04-1773-2004, 1000 ug / mL) The concentrations of the carbon and sulfur standard solutions prepared in this invention are as follows: C: 100.00 ug / mL; S: 10 ug / mL 3. Operating conditions of the carbon-sulfur analyzer: Analysis power: 3.5 W; Analysis time: 50 s.
[0041] 4. The crucible should be 25 mm x 25 mm. Place it in a high-temperature furnace and heat it at 900°C for 1-2 hours, or at 1250°C for 0.5-1 hour. Choose one of the two temperatures, and after cooling, place it in a desiccator for later use.
[0042] The best preparation of high-purity nickel samples is in the form of round rods with a diameter of Ф3 mm to Ф5 mm or square rods with a cross-section of 3 mm × 3 mm to 5 mm × 5 mm. They can also be in the form of fragments, but the surface must be smooth. Place the high-purity nickel sample in a 200 mL glass container, add the organic reagent acetone, and ultrasonically clean for 3–10 min.
[0043] Clean the organic reagents off the sample surface with pure water, soak it in 1:9 hydrochloric acid for 1-3 minutes, rinse the sample surface with pure water to remove any hydrochloric acid residue, and then soak the sample in anhydrous ethanol. Before use, remove the sample with tweezers and let it air dry.
[0044] Weigh out a nickel sac, 0.25 g to 1.50 g of pure iron, and 0.25 g to 1.50 g of tungsten granules and add them to the calcined crucible. Perform a blank test according to the equipment instructions. Perform at least three parallel tests to examine the system blank and ensure that the carbon blank value is less than 0.0003% and the sulfur content blank value is less than 0.0001%.
[0045] The reference reagent series points were placed in the ignited ceramic crucible, and 0.5 g of pure iron flux and 1.5 g of pure tungsten flux were added. The measurements were performed on the carbon-sulfur analyzer according to the equipment operation manual, and a standard curve was plotted. The solid nickel standard sample and the treated high-purity nickel sample were measured under this standard curve to ensure that the measurement results of the solid standard sample were within the uncertainty range of the standard sample.
[0046] Solid nickel standard samples were placed in ignited ceramic crucibles, and nickel bladders, 0.5 g pure iron flux, and 1.5 g pure tungsten flux were added. The samples were measured on a carbon-sulfur analyzer according to the equipment operation manual. A standard curve was plotted on the carbon-sulfur analyzer. The reference reagent standard series samples and the treated high-purity nickel samples were measured under this standard curve.
[0047] The test results obtained after computer data processing are shown in Table 3.
[0048] Example 3 Nickel alloy sample-3#: Nickel content of the main grade of the sample (82.0%) 1. Instruments and equipment used in the experiment: Carbon and sulfur analyzer, COREY600 High-temperature muffle furnace, SXW-8-17 Ultrasonic cleaner, KQ-500B 2. Reagents used in the experiment: 2.1 Secondary pure water 2.2 36%~38% concentrated hydrochloric acid (superior grade, ρ=1.19g / cm3) 2.3 Acetone, superior grade 2.4 Oxygen (99.995%) 2.5 Nitrogen (99.95%) 2.6 Sucrose Standard Material: Sucrose (GBW10067) 2.7 Sulfate standard solution (GSB 04-1773-2004, 1000 ug / mL) The concentrations of the carbon and sulfur standard solutions prepared in this invention are as follows: C: 100.00 ug / mL; S: 10 ug / mL 3. Operating conditions of the carbon-sulfur analyzer: Analysis power: 3.5 W; Analysis time: 50 s.
[0049] 4. The crucible should be 25 mm x 25 mm. Place it in a high-temperature furnace and heat it at 900°C for 1-2 hours, or at 1250°C for 0.5-1 hour. Choose one of the two temperatures, and after cooling, place it in a desiccator for later use.
[0050] The best preparation of high-purity nickel samples is in the form of round rods with a diameter of Ф3 mm to Ф5 mm or square rods with a cross-section of 3 mm × 3 mm to 5 mm × 5 mm. They can also be in the form of fragments, but the surface must be smooth. Place the high-purity nickel sample in a 200 mL glass container, add the organic reagent acetone, and ultrasonically clean for 3–10 min.
[0051] Clean the organic reagents off the sample surface with pure water, soak it in 1:9 hydrochloric acid for 1-3 minutes, rinse the sample surface with pure water to remove any hydrochloric acid residue, and then soak the sample in anhydrous ethanol. Before use, remove the sample with tweezers and let it air dry.
[0052] Weigh out a nickel sac, 0.25 g to 1.50 g of pure iron, and 0.25 g to 1.50 g of tungsten granules and add them to the calcined crucible. Perform a blank test according to the equipment instructions. Perform at least three parallel tests to examine the system blank and ensure that the carbon blank value is less than 0.0003% and the sulfur content blank value is less than 0.0001%.
[0053] The reference reagent series points were placed in the ignited ceramic crucible, and 0.5 g of pure iron flux and 1.5 g of pure tungsten flux were added. The measurements were performed on the carbon-sulfur analyzer according to the equipment operation manual, and a standard curve was plotted. The solid nickel standard sample and the treated high-purity nickel sample were measured under this standard curve to ensure that the measurement results of the solid standard sample were within the uncertainty range of the standard sample.
[0054] Solid standard samples of metallic nickel and metallic cobalt were placed in ignited ceramic crucibles, and nickel sacs, 0.5 g of pure iron flux, and 1.5 g of pure tungsten flux were added. The samples were measured on a carbon-sulfur analyzer according to the equipment operation manual. A standard curve was plotted on the carbon-sulfur analyzer. The reference reagent standard series samples and the treated high-purity nickel sample were measured under this standard curve.
[0055] The test results obtained after computer data processing are shown in Table 4.
[0056] Precision test Eleven separate determination tests were conducted on three batches of nickel samples with different carbon and sulfur contents to examine the precision of the method. The results are shown in Table 5.
[0057] As shown in Table 5, the RSD of carbon and sulfur detection of high-purity nickel is <22.0% within the <0.001% detection range, and <13.2% within the 0.001%~0.005% detection range.
[0058] Spiked recovery test To investigate the recoverability of this method, a sucrose standard sample and a sulfate standard sample with fixed carbon and sulfur contents were added to a high-purity nickel standard sample (carbon content: 0.0015%, sulfur content: 0.0024%), and the determination was carried out according to the procedure of this method, and the recovery rate was calculated.
[0059] As shown in Table 6, the recovery rate of carbon spiked using this method is 95%~103%, and the recovery rate of sulfur spiked is 96%~102%, indicating that the method has good accuracy.
Claims
1. A method for determining the content of ultra-low carbon and sulfur in high-purity nickel, characterized by The determination method comprises the following steps: Step 1, the block, granular or scrap high-purity nickel sample prepared by cutting is placed in a 100 mL glass container, an organic reagent is added for ultrasonic treatment, after the treatment, the organic reagent is discarded, and then pure water is used for cleaning; then inorganic acid is added in the 100 mL glass container, after soaking, the acid cleaning solution is discarded, and then pure water is used for cleaning; Step 2, natural air drying or air dryer drying is selected, and after the water on the surface of the sample is dried, the sample is reserved; Step 3, the ceramic crucible is pretreated: being calcined at 900 DEG C for 1-3 hours or being calcined at 1250 DEG C for 0.5-1 hour; Step 4, after calcination, the crucible is naturally cooled to near room temperature, and then is moved into a desiccator for storage; Step 5, sucrose is used as a carbon reference reagent, and a sulfate standard solution is used as a sulfur reference reagent, the sucrose is solid, the concentration of the sulfate standard solution is 1000 ug / mL, and the solution is configured to a certain concentration; different volumes of the solution are quantitatively taken and placed in a nickel capsule, and then are slowly dried in an 80 DEG C oven to prepare a series of carbon and sulfur standard points; Step 6, a carbon and sulfur standard curve 1 is prepared: 0.1000 g-1.000 g of solid standard samples with carbon and sulfur contents equivalent to those in the high-purity nickel sample are weighed and placed in the calcined ceramic crucible, a certain proportion of fluxing agent is added for determination, a carbon and sulfur working curve is calibrated, and the prepared reference reagent carbon and sulfur standard sample is detected; Step 7, a carbon and sulfur standard curve 2 is prepared: a carbon and sulfur standard solution with a certain concentration is configured by using a reference reagent containing carbon and sulfur elements and a standard solution, a series of standard points are quantitatively taken and placed in a nickel capsule, and then are slowly dried in an oven at 80 DEG C, a certain proportion of pure iron and pure tungsten fluxing agents are added, determination is performed, a carbon and sulfur working curve is calibrated, and a solid standard sample is detected; Step 8, the crucible is placed on a carbon and sulfur analyzer crucible, and sample detection is performed according to a sample analysis program; Step 9, a blank test is prepared according to the operation procedures in steps 1-8; Step 10, the sample to be detected in step 1 is weighed, and detection is performed according to a carbon and sulfur analyzer sample detection program, so that the carbon and sulfur contents in the sample are measured; Step 11, the ultra-low carbon and sulfur contents in the high-purity nickel are calculated according to the following formula, and the obtained results are retained to two significant figures; In the formula: w c is the mass fraction of carbon or sulfur, unit is %, m t is the mass of carbon and sulfur elements in the sample, unit is g; m0is the mass of carbon and sulfur elements in the blank sample, unit is g; c is the mass compensation parameter; m is the mass of the sample, unit is g.
2. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 1, the organic reagent is acetone, the ultrasonic treatment time is 1-10 minutes, the inorganic acid is hydrochloric acid, the proportion of hydrochloric acid added in the glass container is 1:1-1:9, and the soaking time is 1 minute-10 minutes.
3. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 5, the concentration of the reference reagent and the standard solution is configured to be 10 ug / mL-100 ug / mL.
4. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 6, the solid standard sample selects a nickel and nickel alloy matrix and a cobalt matrix.
5. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In steps 6 and 7, the fluxing agent is a combination of two fluxing agents selected from pure iron, pure tungsten and pure tin.
6. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 6, the solid standard sample is used to calibrate the carbon and sulfur working curve.
7. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 7, the standard points configured by the reference reagent or the standard solution are used to calibrate the carbon and sulfur working curve.
8. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 5, characterized in that: When the selected fluxes are pure iron and pure tungsten, the amounts used are 0.5000 g and 1.5000 g, respectively. When the selected fluxes are pure iron and pure tin, the amounts used are 1.5000 g and 0.2000 g, respectively. When the selected fluxes are pure tungsten and pure tin, the amounts used are 1.5000 g and 0.2000 g, respectively.
9. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 9, the average carbon blank value is less than 0.0003%, and the average sulfur blank value is less than 0.0001%.
10. The method for determining the content of ultra-low carbon and sulfur in high-purity nickel according to claim 1, characterized in that: In step 10, the sample weight of the high-purity nickel to be tested ranges from 0.1000 g to 1.000 g.