GB/T 14849.3-1993 Chemical analysis method for industrial silicon - Determination of calcium content
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method for industrial silicon
Determination of calcium content
Silicon metal-Determination
of calcium content
GB/T 14849.3--93
Part I Method 1 Determination of calcium content by flame atomic absorption spectrometry 1 Content and scope of application
This method specifies the determination method of calcium content in industrial silicon. This method is applicable to the determination of calcium content in industrial silicon. Determination range: 0.05% to 1.20%. 2 Reference standards
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB1467 General principles and general provisions for chemical analysis method standards for metallurgical products GB7728 General principles for chemical analysis of metallurgical products by flame atomic absorption spectrometry 3 Basic requirements for preparation
This method is prepared in accordance with the provisions of GB1.4.GB1467 and GB7728. 4 Principle of the method
The sample is decomposed with hydrofluoric acid and nitric acid, and silicon, fluorine, etc. are removed by fuming perchloric acid. The residue is dissolved with hydrochloric acid. The interference of aluminum is suppressed by lanthanum salt, and the absorbance of calcium is measured at a wavelength of 422.7nm on the atomic absorption spectrometer with air-acetylene flame. 5 Reagents
5.1 Perchloric acid (pl.67g/mL).
5.2 Hydrofluoric acid (pl.14 g/ml).
5.3 Nitric acid (1+1).
5.4 Hydrochloric acid (1+1).
5.5 Lanthanum salt solution (10g/L): Weigh 5.00g of lanthanum oxide and place it in a 250mL beaker. Add 15mL of hydrochloric acid (5.4), dissolve with slight heat, and cool to room temperature. Transfer to a 500mL volumetric flask, dilute to the mark with water, and mix well. 5.6 Calcium standard stock solution: weigh 0.6243g of standard calcium carbonate that has been dried at 105℃ and cooled to room temperature in a desiccator into a beaker, add about 20mL of water, then drop hydrochloric acid (5.4) until completely dissolved and 10mL in excess, heat to boil to drive off carbon dioxide, and cool to room temperature. Transfer to a 500ml volumetric flask, dilute to scale with water, and mix. This solution contains 500ug calcium in 1mL. 5.7 Calcium standard solution: transfer 25.00mL of calcium standard stock solution (5.6) into a 250ml volumetric flask, dilute to scale with water, and mix. This solution contains 50μg calcium in 1mL.
Approved by the State Administration of Technical Supervision on December 24, 1993, and implemented on September 1, 1994
6 Instruments
GB/T 14849.3-93
Atomic absorption spectrometer with calcium hollow cathode lamp. Under the best working conditions of the instrument, any instrument that can meet the following indicators can be used. Sensitivity: In a solution that is consistent with the matrix of the sample solution, the characteristic concentration of calcium should not be greater than 42/m!. Precision: When the absorbance is measured 10 times with the highest concentration standard solution, its standard deviation should not exceed 1.5% of the average absorbance value. When the absorbance is measured 10 times with the lowest concentration standard solution (not the zero standard solution), its standard deviation should not exceed 0.5% of the average absorbance value of the highest concentration standard solution.
Linearity of working curve: Divide the working curve into segments according to concentration. The difference between the absorbance value of the highest segment and the absorbance value of the lowest segment should not be less than 0.7.
See Appendix A (reference) for instrument working conditions. 7 Analysis steps
7.1 Sample
The sample particle size passes through a 0.149mm sieve diameter, and the iron powder is removed by a magnet. 7.2 Sample
Weigh 0.5000 of sample (7.1).
7.3 Blank test
Carry out a blank test with the sample.
7.4 Determination
7.4.1 Add 10ml of hydrofluoric acid (5.2) to 100ml of platinum, and add nitric acid (5.3) dropwise until most of the sample is dissolved. Add 1ml of perchloric acid (5.1), and heat until the sample is dissolved and smoke is gone. Remove and cool 7.4.2 Add 5ml of hydrochloric acid (5.4), wash a little water along the wall of III, heat to completely dissolve the residue, and cool to room temperature. Transfer to a 10 ml container, dilute to the mark with water, and mix. 7.4.3 Transfer the test solution (7.4.2) according to Table 1 to a 100 ml container, add 10 ml of lanthanum salt solution (5.5), dilute to the mark with water, and mix.
Calcium content.%
0. 05 ~0. 20
20. 201. 20
Transfer test solution volume.nl.
7.4.4 Using an air-acetylene flame, measure the absorbance of the standard solution at a wavelength of 422.7 mm on an atomic absorption spectrometer with water. Find the calcium concentration of the test solution and the blank test solution from the I curve. 7.5 Drawing of working curve
7.5.1 When the calcium content is 0.05%~~0.20%, take 0.00, 2.00, 4.00, 6.00, 8.00, 10.00mL of calcium standard solution (5.7) and place them in 100mL volumetric flasks respectively, add 10mL of lanthanum salt solution (5.5) and 2.5mL of hydrochloric acid (5.4) to each, dilute to the scale with water and mix well.
7.5.2 When the calcium content is 0.20%1.20%, take 0.00.2.00, 4.00, 6.00, 8.00, 10.00, 12.00mL of calcium standard solution ( 5.7) are placed in a group of 100mL volumetric flasks, and 10mL of saline solution (5.5) and 0.5mL of hydrochloric acid (5.4) are added to each, diluted to the scale with water, and mixed.
7.5.3 Under the same conditions as the test solution, measure the absorbance of the standard solution (7.5.1) and (7.5.2), subtract the absorbance of the zero concentration solution, and draw a working curve with the calcium concentration as the horizontal axis and the absorbance as the vertical axis. 310
8 Expression of analysis results
Calculate the percentage of calcium according to the following formula:
GB/T14849.3--93
Ca(%) (cn*+ V2: YX J0
Wherein: c-concentration of calcium in the test solution obtained on the straight working line, ug/m. (i-concentration of calcium in the test solution obtained on the working curve, μg/mL; V.total volume of the test solution.mI..
V.volume of the test solution transferred mL
V——volume of the tested solution, mL;
9Allowable difference
·mass of the test material.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
0. 050~~0. 250
>0. 250-~0. 450
20. 450~-0. 700
>0. 700-~1. 200
Part II Method 2 Chlorophosphine Azo 1 Determination of calcium content by spectrophotometry 10 Subject content and scope of application
This method specifies the determination method of calcium content in industrial silicon. This method is applicable to the determination of calcium content in industrial silicon, with a determination range of 0.05% to 1.20%. In case of dispute over the analysis results, the method 1 Determination of calcium content by flame atomic absorption spectrometry shall be used as the reference analysis method. 11 Reference standards
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB1467 General principles and general provisions for chemical analysis method standards for metallurgical products GB7729 General principles for spectrophotometric methods for chemical analysis of metallurgical products 12 Basic requirements for preparation
This standard is prepared in accordance with the provisions of GB1.4, GB1467 and GB7729. 13 Principle of the method
The sample is decomposed with hydrofluoric acid and nitric acid, and silicon, fluorine, etc. are removed by sulfuric acid bubbling. The residue is dissolved with hydrochloric acid. Use triethanolamine, 1.10. azophenanthracene acetylacetone to mask the interfering element. At pH 10-10.5, calcium forms a colored complex with chlorophosphonazo. The absorbance is measured at a wavelength of 580 nm using the EGTA-Ph fading solution as a reference. 14 Reagents
14.1 Hydrofluoric acid (pl.14 g/mL).
14.2 Nitric acid (1+1).
14.3 Sulfuric acid (1+1).
14.4 Hydrochloric acid (1+1).
14.5 Triethanolamine (1+3). Store in polyethylene bottle 4. 14.6 1,10-Dichlorophenanthroline ethanol solution (4g/1): Weigh 4.0g 1,10-dichlorophenanthroline (CHfN,·H0). Place in a 1000ml volumetric flask, add ethanol to dissolve, dilute to scale with ethanol, and mix. 14.7 Acetylacetone (1+40).
14.8 Buffer solution: Weigh 21.00g borax Na,BO, ·10112)), 4.00)g sodium hydroxide (superior grade) dissolved in water and diluted to 1000mL. The pH of this solution is 10.5. Store in a polyethylene bottle. 14.9 Chlorophosphonazo I (C1H1:OuN,S,PCi) solution (1.0g/L). 14.10 EGTA-Pb solution (0.02mol/L): Weigh 1.90g ethylene glycol diethyl ether diamine acetic acid (EGTA) and place it in a beaker. Add about 100mL of water, heat, add sodium hydroxide (1mol/L) dropwise to help dissolve, and adjust to neutral. Take another 1.53g lead chloride. Add about 100ml of water, heat to dissolve, mix the two solutions while hot, adjust to neutral, cool and dilute with water to 250mL, mix well. 14.11 Calcium standard stock solution: weigh 2.4970g of standard calcium carbonate that has been dried at 105°C and cooled to room temperature in a desiccator into a beaker, add about 200mL of water, then add hydrochloric acid (14.4) dropwise until completely dissolved and 20mL in excess, heat and boil to drive off carbon oxides, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and mix. This solution contains 1mg calcium per ml. 14.12 Calcium standard solution: transfer 10.00ml of calcium standard stock solution (14.11) into a 1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 10μg calcium per ml.
15 Instruments
15.1 Spectrophotometer.
15.2 Acidometer.
16 Analysis steps
16.1 Sample
The sample particle size passes through a 100 mesh, and the iron powder is sucked away by a magnet. 16.2 Sample
Weigh 1.0000g of sample (16.1).
16.3 Blank test
Carry out a blank test with the sample.
16.4 Determination
16.4.1 Place the sample in 100mL of platinum III, add 0.5mL of sulfuric acid (14.3), 20~25ml. of hydrofluoric acid (14.1), and add nitric acid (14.2) dropwise in batches until most of the sample is dissolved. Move the platinum dish to a sand bath, heat until the sample is completely dissolved and evaporated to dryness. 16.4.2 Place the platinum dish in a high-temperature furnace at 450±25℃ until all sulfuric acid fumes are gone, take it out, and cool it. 16.4.3 Add 5.0 mL of hydrochloric acid (14.4) and wash along the blood wall with 20~30 mL of water. Heat to completely dissolve the residue and cool. 16.4.4 Transfer the test solution into a volumetric flask according to Table 3, dilute to the mark with water, and mix well. 312
Calcium content.%
0.05~0.30
20. 30 -~-0. 60
-0. 60-1. 20
GB/T14849.3--93
Total volume of test solution, mlL.
16.4.5 Divide the test solution (16.4.4) into a 50 mL volumetric flask according to Table 1. Take a test solution of volume .ml.
16.4.6 and add 6.0mL triethanolamine (14.5), 4.0mL 1,10-phenanthroline ethanol solution (14.6), 3.0mL acetylacetone (14.7), 10.0mL buffer solution (14.8), 5.0mL chlorophosphine azo solution (14.9). Mix well after adding each reagent. Dilute to scale with water and mix well. Let stand for 5 minutes.
16.4.7 Transfer the solution (16.4.6) into a 2 cm absorption III, add 3 to 5 drops of EGTA-Ph solution (11.10) to the remaining solution, shake well until it fades completely, use this faded solution as a reference, measure its absorbance at a wavelength of 580 nm on a spectrophotometer, 16.4.8 Subtract the absorbance of the blank test solution (16.3), and find the corresponding mass of calcium from the working curve. 16.5 Drawing of the working curve
16.5.1 Transfer 0.000.50, 1.00, 2.00. 3.00, 4.00, 5.00, 6.00 mL of the calcium standard solution (14.12) into 50 mL volumetric flasks respectively, add the blank test solution (16.3) with an equal volume of the test solution, and proceed as in 16.4.6 and 16.4.7. 16.5.2 Draw the working curve with the mass of calcium as the horizontal axis and the absorbance after subtracting the reagent blank absorbance as the vertical axis. 17 Expression of analysis results
Calculate the percentage of calcium according to the following formula:
Ca(%) m :V. × 10
Where: m is the mass of calcium found from the working curve, gV. Total volume of test solution, mL;
V, volume of one part of test solution, nL,
18 Allowable difference
The mass of the sample, g.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 4. Table 4
0.050-~ 0.250
0.250~~0.450
0.450~0.700
>0.700~1.200
GB/T14849.3--93
Appendix A
Instrument working conditions
(reference)
The reference working conditions for measuring calcium using WYX-401 atomic absorption spectrometer are shown in Table A1. Table A1
Additional notes:
Monochromator passband
Lamp current
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Fushun Aluminum Plant.
Height of burner
Method 1 of this standard was drafted by Zhengzhou Light Metal Research Institute, and Method 2 was drafted by Fugu Aluminum Factory. The drafters of Method 1 of this standard are Li Jian and Zheng Wenliang; the drafter of Method 2 is Miyamoto Ting, Air flow
Acetic acid flow
From the date of implementation of this standard, YB95-76 "Chemical Analysis Method of Industrial Silicon" issued by the former Ministry of Metallurgical Industry of the People's Republic of China will be invalid.1,10-phenanthroline ethanol solution (14.6), 3.0ml acetylacetone (14.7), 10.0ml buffer solution (14.8), 5.0ml chlorophosphine azo solution (14.9). Mix well after adding each reagent. Dilute to scale with water and mix well. Let stand for 5 minutes.
16.4.7 Transfer the solution (16.4.6) into a 2 cm absorption III, add 3 to 5 drops of EGTA-Ph solution (11.10) to the remaining solution, shake well until it fades completely, use this faded solution as a reference, measure its absorbance at a wavelength of 580 nm on a spectrophotometer, 16.4.8 Subtract the absorbance of the blank test solution (16.3), and find the corresponding mass of calcium from the working curve. 16.5 Drawing of the working curve
16.5.1 Transfer 0.000.50, 1.00, 2.00. 3.00, 4.00, 5.00, 6.00 mL of the calcium standard solution (14.12) into 50 mL volumetric flasks respectively, add the blank test solution (16.3) with an equal volume of the test solution, and proceed as in 16.4.6 and 16.4.7. 16.5.2 Draw the working curve with the mass of calcium as the horizontal axis and the absorbance after subtracting the reagent blank absorbance as the vertical axis. 17 Expression of analysis results
Calculate the percentage of calcium according to the following formula:
Ca(%) m :V. × 10
Where: m is the mass of calcium found from the working curve, gV. Total volume of test solution, mL;
V, volume of one part of test solution, nL,
18 Allowable difference
The mass of the sample, g.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 4. Table 4
0.050-~ 0.250
0.250~~0.450
0.450~0.700
>0.700~1.200
GB/T14849.3--93
Appendix A
Instrument working conditions
(reference)
The reference working conditions for measuring calcium using WYX-401 atomic absorption spectrometer are shown in Table A1. Table A1
Additional notes:
Monochromator passband
Lamp current
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Fushun Aluminum Plant.
Height of burner
Method 1 of this standard was drafted by Zhengzhou Light Metal Research Institute, and Method 2 was drafted by Fugu Aluminum Factory. The drafters of Method 1 of this standard are Li Jian and Zheng Wenliang; the drafter of Method 2 is Miyamoto Ting, Air flow
Acetic acid flow
From the date of implementation of this standard, YB95-76 "Chemical Analysis Method of Industrial Silicon" issued by the former Ministry of Metallurgical Industry of the People's Republic of China will be invalid.1,10-phenanthroline ethanol solution (14.6), 3.0ml acetylacetone (14.7), 10.0ml buffer solution (14.8), 5.0ml chlorophosphine azo solution (14.9). Mix well after adding each reagent. Dilute to scale with water and mix well. Let stand for 5 minutes.
16.4.7 Transfer the solution (16.4.6) into a 2 cm absorption III, add 3 to 5 drops of EGTA-Ph solution (11.10) to the remaining solution, shake well until it fades completely, use this faded solution as a reference, measure its absorbance at a wavelength of 580 nm on a spectrophotometer, 16.4.8 Subtract the absorbance of the blank test solution (16.3), and find the corresponding mass of calcium from the working curve. 16.5 Drawing of the working curve
16.5.1 Transfer 0.000.50, 1.00, 2.00. 3.00, 4.00, 5.00, 6.00 mL of the calcium standard solution (14.12) into 50 mL volumetric flasks respectively, add the blank test solution (16.3) with an equal volume of the test solution, and proceed as in 16.4.6 and 16.4.7. 16.5.2 Draw the working curve with the mass of calcium as the horizontal axis and the absorbance after subtracting the reagent blank absorbance as the vertical axis. 17 Expression of analysis results
Calculate the percentage of calcium according to the following formula:
Ca(%) m :V. × 10
Where: m is the mass of calcium found from the working curve, gV. Total volume of test solution, mL;
V, volume of one part of test solution, nL,
18 Allowable difference bzxZ.net
The mass of the sample, g.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 4. Table 4
0.050-~ 0.250
0.250~~0.450
0.450~0.700
>0.700~1.200
GB/T14849.3--93
Appendix A
Instrument working conditions
(reference)
The reference working conditions for measuring calcium using WYX-401 atomic absorption spectrometer are shown in Table A1. Table A1
Additional notes:
Monochromator passband
Lamp current
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Fushun Aluminum Plant.
Height of burner
Method 1 of this standard was drafted by Zhengzhou Light Metal Research Institute, and Method 2 was drafted by Fugu Aluminum Factory. The drafters of Method 1 of this standard are Li Jian and Zheng Wenliang; the drafter of Method 2 is Miyamoto Ting, Air flow
Acetic acid flow
From the date of implementation of this standard, YB95-76 "Chemical Analysis Method of Industrial Silicon" issued by the former Ministry of Metallurgical Industry of the People's Republic of China will be invalid.
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