Method for determining the sulfur content in pure copper by infrared carbon-sulfur analyzer

Abstract

This invention relates to the field of sulfur content detection technology, specifically providing a method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer. The method includes crucible pretreatment, preparation of analytical materials, and analytical steps, specifically: 1) Crucible pretreatment: S1, placing the ceramic crucible in a muffle furnace for ignition; S2, removing the ceramic crucible, allowing it to cool, and then placing it in a desiccator containing color-changing silica gel; S3, putting the ceramic crucible into use; 2) Preparation of analytical materials: pure copper sample, low-sulfur standard sample; 3) Analyzing the sulfur content in pure copper. This method selects the optimal flux, uses a standard sample from steel as a low-sulfur standard for standardization calibration, and uses tungsten flux, solving the problem of rapid determination of sulfur content in pure copper. This method features simple analytical steps, fast analysis speed, and high accuracy, providing reliable technical support for the smelting, application, and quality control of pure copper, and effectively supporting scientific research and specialized production work.

Description

Technical Field

[0001] This invention relates to the field of sulfur content detection technology, specifically to a method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer. Background Technology

[0002] Pure copper is commonly used in the production of wires and cables, containing over 99.97% copper. It contains trace amounts of impurities, including sulfur. Sulfur doesn't significantly affect the electrical and thermal conductivity of pure copper, but high levels can cause hot brittleness and cracking, leading to a significant decrease in the product's wear resistance and corrosion resistance. If made into cables, the tensile strength of the copper wire will be significantly reduced, making it prone to breakage. During the production process, the sulfur content of pure copper is carefully controlled; high-purity pure copper typically has a very low sulfur content, less than 10 ppm.

[0003] Because sulfur content in pure copper is low, its detection process is relatively difficult. Currently, the most commonly used method is inductively coupled plasma atomic emission spectrometry (ICP-AES). However, this method involves complex sample pretreatment and long sample preparation time, resulting in low overall analytical efficiency. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer, which solves the problems of difficult process, complex pretreatment and low analysis efficiency in the prior art for detecting the sulfur content in pure copper.

[0005] To achieve the above and other related objectives, this invention provides a method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer. The method includes crucible pretreatment, preparation of analytical materials, and analytical determination steps, specifically including:

[0006] 1) Crucible pretreatment:

[0007] S1. Place the ceramic crucible in a muffle furnace and calcine at 1100℃ for 2 hours;

[0008] S2. Remove the ceramic crucible and place it in a desiccator after it has cooled down. At the same time, put color-changing silica gel in the desiccator to absorb the moisture in the ceramic crucible.

[0009] S3. Place the ceramic crucible in an infrared carbon-sulfur analyzer for use;

[0010] 2) Prepare the following materials for the test: pure copper sample, tungsten flux, and low-sulfur standard sample;

[0011] 3) Analyze the sulfur content in pure copper:

[0012] A1. Analyze the blank value b of sulfur in tungsten flux: Weigh a certain amount of tungsten flux and place it in a ceramic crucible. Input the corresponding value of the tungsten flux amount into the infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the blank value b of sulfur in the tungsten flux.

[0013] A2. Analyze the initial sulfur content value c1 in the copper-tungsten mixture: Weigh a certain amount of pure copper sample and an equal amount of tungsten flux and mix them in a ceramic crucible. Input the corresponding pure copper sample amount into the infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the initial sulfur content value c1 in the copper-tungsten mixture.

[0014] A3. Calculate the actual sulfur content value c2 in the copper-tungsten mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2 to obtain the actual sulfur content value c2 in the copper-tungsten mixture.

[0015] A4. Calculate the theoretical sulfur content value 5b in the mixture: Based on the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2, weigh out the amount of the copper-tungsten mixture and the amount of the low-sulfur standard sample, so that the sulfur content in the low-sulfur standard sample is the same as the sulfur content in the copper-tungsten mixture, and obtain the theoretical sulfur content value 5b in the mixture.

[0016] A5. Calculate the comprehensive sulfur content value d in the mixture: Mix the copper-tungsten mixture weighed in step A4 with the low sulfur standard sample and place it in a ceramic crucible. Input the value corresponding to 5 times the amount of the low sulfur standard sample into the infrared carbon-sulfur analyzer, and then perform oxygen combustion to determine and analyze the combustion products to obtain the comprehensive sulfur content value d in the mixture.

[0017] A6. Calculate the sulfur content value e in the mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the comprehensive sulfur content value d obtained in step A5 to obtain the sulfur content value e in the mixture.

[0018] A7. Calculate the correction factor f: Calculate the ratio of the theoretical sulfur content value 5b in the mixture to the sulfur content value e in the mixture, and obtain the correction factor f.

[0019] A8. Calculate the actual sulfur content value g in the pure copper sample: Multiply the actual sulfur content value c2 in the copper-tungsten mixture obtained in step A3 with the correction coefficient obtained in step A7 to obtain the actual sulfur content value g in the pure copper sample.

[0020] In one embodiment of the present invention, in step 2), the pure copper sample needs to be cut into small pieces with a size of less than 5 mm for later use.

[0021] In one embodiment of the present invention, in step 2), the sulfur blank value of the selected tungsten flux is less than 0.0003%.

[0022] In one embodiment of the present invention, in step 2), the low-sulfur standard sample selected is industrial pure iron YSBC281124b, wherein S = 0.0038%.

[0023] In one embodiment of the present invention, step A1 is repeated at least three times, and the average value of the blank value b of sulfur in the tungsten flux obtained multiple times is used.

[0024] In one embodiment of the present invention, step A2 is repeated at least three times, and the average value of the initial sulfur content c1 in the multiple copper-tungsten mixtures is used.

[0025] In one embodiment of the present invention, step A5 is repeated at least three times, and the average value of the comprehensive sulfur content d in the multiple mixtures is used.

[0026] As described above, the method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer of the present invention has the following advantages:

[0027] Beneficial effects:

[0028] This invention uses a high-frequency infrared sulfur analyzer as the measuring instrument and high-purity tungsten as the flux. The SO2 gas produced after oxygen combustion of a pure copper sample in the analyzer strongly absorbs infrared light of a specific wavelength. The sulfur content in the sample is determined by measuring the change in infrared light intensity before and after entering the infrared detection cell. This method selects the optimal flux and uses a standard steel sample as a low-sulfur standard for standardization and calibration. Combined with the tungsten flux, it solves the problem of rapidly determining the sulfur content in pure copper. This method features simple analytical steps, fast analysis speed, and high accuracy, providing reliable technical support for the smelting, application, and quality control of pure copper, and effectively supporting scientific research and specialized production work. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0030] Example 1

[0031] This invention provides a method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer. The method includes crucible pretreatment, preparation of reagents for the determination, and analytical determination steps.

[0032] 1) Crucible pretreatment:

[0033] S1. Place the ceramic crucible in a muffle furnace and calcine at 1100℃ for 2 hours;

[0034] S2. Remove the ceramic crucible and place it in a desiccator after cooling. Simultaneously, place color-changing silica gel in the desiccator to absorb the moisture in the ceramic crucible. Color-changing silica gel is an indicator adsorbent with high added value and high technical content, made from fine porous silica gel with high activity as the base material through deep processing. It belongs to high-end adsorption desiccants. It has the strong adsorption effect of fine porous silica gel on water vapor in the medium (such as air or industrial gases). It is mainly used for moisture absorption and rust prevention of instruments, meters, equipment, etc. under closed conditions. At the same time, it can visually indicate the relative humidity of the environment by changing its color from blue to red after absorbing moisture. It can replace traditional desiccants to absorb water and make the sulfur release curve more perfect and without tailing in subsequent analysis and measurement processes.

[0035] S3. Place the ceramic crucible in an infrared carbon-sulfur analyzer for use;

[0036] The S1-S3 process can dehumidify the crucible surface, preventing residual moisture from causing minor errors in subsequent use and resulting in inaccurate measurement data.

[0037] 2) Prepare the following materials for the test: pure copper sample, tungsten flux, and low-sulfur standard. The pure copper sample should be cut into small pieces less than 5 mm in size. Since the sulfur content in pure copper is extremely low, the addition of blanks should be minimized during the analysis, mainly the sulfur blank value in the tungsten flux, to avoid affecting the test data. Therefore, the sulfur blank value of the selected tungsten flux is less than 0.0003%. The selected low-sulfur standard is industrial pure iron YSBC281124b, in which S = 0.0038%. It is a standard sample in steel and can be standardized and calibrated. When used with tungsten flux, it is beneficial for the rapid determination of sulfur content in pure copper.

[0038] 3) Analyze the sulfur content in pure copper:

[0039] A1. Analyze the blank value b of sulfur in tungsten flux: Weigh a certain amount of tungsten flux and place it in a ceramic crucible. Input the corresponding value of the tungsten flux amount into an infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the blank value b of sulfur in the tungsten flux. Step A1 should be repeated at least three times, and the average value of the blank values ​​b of sulfur in the tungsten flux obtained from the multiple times should be used.

[0040] A2. Analyze the initial sulfur content value c1 in the copper-tungsten mixture: Weigh a certain amount of pure copper sample and an equal amount of tungsten flux, mix them in a ceramic crucible, input the corresponding pure copper sample amount into an infrared carbon-sulfur analyzer, and analyze the combustion products after oxygen combustion to obtain the initial sulfur content value c1 in the copper-tungsten mixture; Step A2 should be repeated at least three times, and the average value of the initial sulfur content value c1 obtained from the multiple times should be used.

[0041] A3. Calculate the actual sulfur content value c2 in the copper-tungsten mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2 to obtain the actual sulfur content value c2 in the copper-tungsten mixture.

[0042] A4. Calculate the theoretical sulfur content value 5b in the mixture: Based on the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2, weigh out the amount of the copper-tungsten mixture and the amount of the low-sulfur standard sample, so that the sulfur content in the low-sulfur standard sample is the same as the sulfur content in the copper-tungsten mixture, and obtain the theoretical sulfur content value 5b in the mixture.

[0043] A5. Calculate the comprehensive sulfur content value d in the mixture: Mix the copper-tungsten mixture weighed in step A4 with the low-sulfur standard sample in a ceramic crucible. Input the value corresponding to 5 times the amount of the low-sulfur standard sample into the infrared carbon-sulfur analyzer. After oxygen combustion, analyze the combustion products to obtain the comprehensive sulfur content value d in the mixture. Step A5 should be repeated at least three times, and the average value of the comprehensive sulfur content value d obtained from the multiple tests should be used.

[0044] A6. Calculate the sulfur content value e in the mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the comprehensive sulfur content value d obtained in step A5 to obtain the sulfur content value e in the mixture.

[0045] A7. Calculate the correction factor f: Calculate the ratio of the theoretical sulfur content value 5b in the mixture to the sulfur content value e in the mixture, and obtain the correction factor f.

[0046] A8. Calculate the actual sulfur content value g in the pure copper sample: Multiply the actual sulfur content value c2 in the copper-tungsten mixture obtained in step A3 with the correction coefficient obtained in step A7 to obtain the actual sulfur content value g in the pure copper sample.

[0047] Example 2

[0048] The specific analytical data on the sulfur content in pure copper are as follows:

[0049] A1. Analyzing the blank value of sulfur in tungsten flux: b) Weigh 1.5g of tungsten flux and place it in a ceramic crucible. Input the weight of 1.5g into an infrared carbon-sulfur analyzer. After oxygen combustion, analyze the combustion products. Analyze three times to obtain the blank values ​​of sulfur as follows:

[0050] 0.00016%, 0.00018%, 0.00019%, with an average of 0.00018%;

[0051] Therefore, the blank value of sulfur in the tungsten flux is b = 0.00018%.

[0052] A2. Analysis of the initial sulfur content c1 in the copper-tungsten mixture: Weigh 1g of pure copper sample + 1g of tungsten flux, input the weight 1g into the infrared carbon-sulfur analyzer, and analyze the combustion products after oxygen combustion. The initial sulfur content values ​​were obtained from three analyses as follows:

[0053] The values ​​of 0.00074%, 0.00078%, and 0.00076% were averaged to yield an initial content of approximately 0.00076%.

[0054] The initial sulfur content in the copper-tungsten mixture is c1 = 0.00076%.

[0055] A3. Calculate the actual sulfur content value c2 in the copper-tungsten mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2, i.e. 0.00076%--0.00018%=0.00058%.

[0056] Therefore, the actual sulfur content in the copper-tungsten mixture is c2 = 0.00058%.

[0057] A4. Calculate the theoretical sulfur content 5b in the mixture: Based on the initial sulfur content c1 = 0.00076% obtained in step A2, weigh out 1g of the copper-tungsten mixture and 0.2g of the low-sulfur standard sample. The sulfur content of the low-sulfur standard sample is 0.2 * 0.0038% = 0.00076%, which is equivalent to the sulfur content of 1g of the copper-tungsten mixture. Therefore, the theoretical analysis result should be 0.00076%, so 5b = 0.00076%.

[0058] A5. Calculate the comprehensive sulfur content value d in the mixture: Mix the copper-tungsten mixture weighed in step A4 with the low-sulfur standard sample in a ceramic crucible. Input the value corresponding to 5 times the amount of the low-sulfur standard sample into the infrared carbon-sulfur analyzer. After oxygen combustion, analyze the combustion products. Analyze three times and obtain the following results:

[0059] 0.00089%, 0.00091%, 0.00092%, the average value is 0.00081%;

[0060] The total sulfur content in the mixture is d = 0.00081%.

[0061] A6. Calculate the sulfur content value e in the mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the comprehensive sulfur content value d obtained in step A5. 0.00081% - 0.00018% = 0.00073%, then the sulfur content value e in the mixture is 0.00073%.

[0062] A7. Calculate the correction factor f: Calculate the ratio of the theoretical sulfur content value 5b in the mixture to the sulfur content value e in the mixture, 0.00076% / 0.00073% = 1.041, and obtain the correction factor f = 1.041.

[0063] A8. Calculate the actual sulfur content value g in the pure copper sample: Multiply the actual sulfur content value c2 in the copper-tungsten mixture obtained in step A3 by the correction coefficient obtained in step A7, 0.00058% * 1.041 = 0.0006%, and obtain the actual sulfur content value g in the pure copper sample = 0.0006%.

[0064] In summary, this invention uses a high-frequency infrared sulfur analyzer as the measuring instrument and high-purity tungsten as the flux. The SO2 gas produced after oxygen combustion of a pure copper sample in the high-frequency infrared sulfur analyzer strongly absorbs infrared light of a specific wavelength. The sulfur content in the sample is determined by measuring the change in infrared light intensity before and after entering the infrared detection cell. This method selects the optimal flux and uses a standard steel sample as a low-sulfur standard for standardization and calibration, combined with the tungsten flux, thus solving the problem of rapidly determining the sulfur content in pure copper. This method features simple analytical steps, fast analysis speed, and high accuracy, providing reliable technical support for the smelting, application, and quality control of pure copper, and effectively supporting scientific research and specialized production work. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer, characterized in that, The method includes crucible pretreatment, preparation of reagents for analysis, and analytical determination steps, specifically including: 1) Crucible pretreatment: S1. Place the ceramic crucible in a muffle furnace and calcine at 1100℃ for 2 hours; S2. Remove the ceramic crucible and place it in a desiccator after it has cooled down. At the same time, put color-changing silica gel in the desiccator to absorb the moisture in the ceramic crucible. S3. Place the ceramic crucible in an infrared carbon-sulfur analyzer for use; 2) Prepare the necessary materials for the test: pure copper sample and low-sulfur standard sample; 3) Analyze the sulfur content in pure copper: A1. Analyze the blank value b of sulfur in tungsten flux: Weigh a certain amount of tungsten flux and place it in a ceramic crucible. Input the corresponding value of the tungsten flux amount into the infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the blank value b of sulfur in the tungsten flux. A2. Analyze the initial sulfur content value c1 in the copper-tungsten mixture: Weigh a certain amount of pure copper sample and an equal amount of tungsten flux and mix them in a ceramic crucible. Input the corresponding pure copper sample amount into the infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the initial sulfur content value c1 in the copper-tungsten mixture. A3. Calculate the actual sulfur content value c2 in the copper-tungsten mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2 to obtain the actual sulfur content value c2 in the copper-tungsten mixture. A4. Calculate the theoretical sulfur content value 5b in the mixture: Based on the initial sulfur content value c1 in the copper-tungsten mixture obtained in step A2, weigh out the amount of the copper-tungsten mixture and the amount of the low-sulfur standard sample, so that the sulfur content in the low-sulfur standard sample is the same as the sulfur content in the copper-tungsten mixture, and obtain the theoretical sulfur content value 5b in the mixture. A5. Calculate the comprehensive sulfur content value d in the mixture: Mix the copper-tungsten mixture weighed in step A4 with the low-sulfur standard sample and place it in a ceramic crucible. Input the value corresponding to 5 times the amount of the low-sulfur standard sample into the infrared carbon-sulfur analyzer. After oxygen combustion, measure and analyze the combustion products to obtain the comprehensive sulfur content value d in the mixture. A6. Calculate the sulfur content value e in the mixture: Subtract the blank value b of sulfur in the tungsten flux obtained in step A1 from the comprehensive sulfur content value d obtained in step A5 to obtain the sulfur content value e in the mixture. A7. Calculate the correction factor f: Calculate the ratio of the theoretical sulfur content value 5b in the mixture to the sulfur content value e in the mixture, and obtain the correction factor f. A8. Calculate the actual sulfur content value g in the pure copper sample: Multiply the actual sulfur content value c2 in the copper-tungsten mixture obtained in step A3 with the correction coefficient obtained in step A7 to obtain the actual sulfur content value g in the pure copper sample.

2. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 1, characterized in that: In step 2), the pure copper sample needs to be cut into small pieces with a size of less than 5 mm for later use.

3. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 2, characterized in that: In step 2), the sulfur blank value of the selected tungsten flux is less than 0.0003%.

4. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 3, characterized in that: In step 2), the low-sulfur standard sample selected is industrial pure iron YSBC281124b, where S = 0.0038%.

5. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 1, characterized in that: Step A1 is repeated at least three times, and the average value of the blank value b of sulfur in the tungsten flux obtained from the multiple times is used.

6. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 1, characterized in that: Step A2 is repeated at least three times, and the average value of the initial sulfur content c1 obtained from the multiple copper-tungsten mixtures is used.

7. The method for determining the sulfur content in pure copper using an infrared carbon-sulfur analyzer according to claim 1, characterized in that: Step A5 is repeated at least three times, and the average value of the comprehensive sulfur content d obtained from the multiple mixtures is used.