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GB/T 20975.10-2020: Methods for chemical analysis of aluminium and aluminium alloys - Part 10: Determination of tin content
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Methods for chemical analysis of aluminium and aluminium alloys - Part 10: Determination of tin content
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Methods for chemical analysis of aluminium and aluminium alloys -- Part 10: Determination of tin content
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Basic data | Standard ID | GB/T 20975.10-2020 (GB/T20975.10-2020) | | Description (Translated English) | Methods for chemical analysis of aluminium and aluminium alloys - Part 10: Determination of tin content | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | H12 | | Classification of International Standard | 77.120.10 | | Word Count Estimation | 10,197 | | Date of Issue | 2020-06-02 | | Date of Implementation | 2021-04-01 | | Older Standard (superseded by this standard) | GB/T 20975.10-2008 | | Quoted Standard | GB/T 8005.2; GB/T 8170-2008 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | | Summary | This standard specifies the determination of tin content in aluminum and aluminum alloys by phenylfluorescein spectrophotometry and potassium iodate titration method. This standard applies to the arbitration determination of tin content in aluminum and aluminum alloys. Determination range of phenylfluorescein spectrophotometry: 0.005 0%��2.00%; Determination range of potassium iodate titration method: 0.35%��55.00%. The phenylfluorescein spectrophotometry in this standard is not applicable to the determination of bismuth mass fraction > 0.20% or magnesium mass fraction > 4.0% aluminum alloy. | GB/T 20975.10-2020: Methods for chemical analysis of aluminium and aluminium alloys - Part 10: Determination of tin content
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Methods for chemical analysis of aluminium and aluminium alloys--Part 10.Determination of tin content
ICS 77.120.10
H12
National Standards of People's Republic of China
Replace GB/T 20975.10-2008
Chemical analysis methods of aluminum and aluminum alloys
Part 10.Determination of tin content
2020-06-02 released
Implementation on 2021-04-01
State Administration for Market Regulation
Issued by the National Standardization Management Committee
Foreword
GB/T 20975 "Methods for Chemical Analysis of Aluminum and Aluminum Alloys" is divided into 37 parts.
---Part 1.Determination of mercury content;
---Part 2.Determination of arsenic content;
---Part 3.Determination of copper content;
---Part 4.Determination of iron content;
---Part 5.Determination of silicon content;
---Part 6.Determination of cadmium content;
---Part 7.Determination of manganese content;
---Part 8.Determination of zinc content;
---Part 9.Determination of lithium content by flame atomic absorption spectrometry;
---Part 10.Determination of tin content;
---Part 11.Determination of lead content;
---Part 12.Determination of titanium content;
---Part 13.Determination of vanadium content;
---Part 14.Determination of nickel content;
---Part 15.Determination of boron content;
---Part 16.Determination of magnesium content;
---Part 17.Determination of strontium content;
---Part 18.Determination of chromium content;
---Part 19.Determination of Zirconium Content;
---Part 20.Determination of Gallium Content Butyl Rhodamine B Spectrophotometry;
---Part 21.Determination of calcium content;
---Part 22.Determination of beryllium content;
---Part 23.Determination of antimony content;
---Part 24.Determination of total rare earth content;
---Part 25.Determination of element content by inductively coupled plasma atomic emission spectrometry;
---Part 26.Determination of carbon content by infrared absorption method;
---Part 27.Determination of cerium, lanthanum and scandium content by inductively coupled plasma atomic emission spectrometry;
---Part 28.Determination of cobalt content by flame atomic absorption spectrometry;
---Part 29.Determination of molybdenum content thiocyanate spectrophotometric method;
---Part 30.Determination of hydrogen content by heating extraction thermal conductivity method;
---Part 31.Determination of phosphorus content molybdenum blue spectrophotometric method;
---Part 32.Determination of Bismuth Content;
---Part 33.Determination of potassium content by flame atomic absorption spectrometry;
---Part 34.Determination of sodium content by flame atomic absorption spectrometry;
---Part 35.Determination of Tungsten Content Thiocyanate Spectrophotometric Method;
---Part 36.Determination of silver content by flame atomic absorption spectrometry;
--- Part 37.Determination of Niobium Content.
This part is part 10 of GB/T 20975.
This section was drafted in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 20975.10-2008 "Methods for Chemical Analysis of Aluminum and Aluminum Alloy Part 10.Determination of Tin Content", and
Compared with GB/T 20975.10-2008, the main technical changes except for editorial changes are as follows.
--- Added standard use safety warnings;
---Modified the "range", the measurement range of phenylfluorone spectrophotometry was extended to 0.0050%~2.00%, and the measurement by iodate titration method
The specified range was extended from 0.35% to 55.00%, which increased the inapplicability of phenylfluorone spectrophotometry (see Chapter 1,.2008
Chapter 1 and Chapter 10 of the edition);
--- Added "Normative Reference Documents" (see Chapter 2);
--- Added "Terms and Definitions" (see Chapter 3);
---Modified the precision of "Phenylfluorone Spectrophotometry" (see 4.7, Chapter 8 of the.2008 edition);
---Modified the "potassium iodate titration method" (see Chapter 5, Chapter 10 ~ Chapter 16 of the.2008 edition);
--- Deleted "Quality Assurance and Control" (see Chapter 9 of the.2008 edition);
---Added test report (see Chapter 6).
This part was proposed by China Nonferrous Metals Industry Association.
This part is under the jurisdiction of the National Nonferrous Metals Standardization Technical Committee (SAC/TC243).
Drafting organizations of this section. Northeast Light Alloy Co., Ltd., South China University of Technology, Non-ferrous Metals Technology and Economic Research Institute, Xi'an Hantang Branch
Analysis and Testing Co., Ltd., Kunming Research Institute of Metallurgy, Changsha Research Institute of Mining and Metallurgy Co., Ltd., Guizhou Province Analysis and Testing Research Institute, Inner Mongolia Jinlian
Aluminum Materials Co., Ltd., Chinalco Ruimin Co., Ltd., and Zhongshi High-tech Materials Co., Ltd.
The main drafters of this section. Li Wenzhi, Dai Fengying, Xi Huan, Xiang Xinghua, Cui Shuang, Liu Weili, Fu Rao, Wang Andi, Lan Wangui, Yuan Jianchang,
Yang Junhong, Lan Zheng, Yang Ruiqing, Wan Mang, Zhou Bing, Yang Wei, Wu Qingchun, Song Guosheng, Liu Qing, Zou Deling, Wang Yina, Shan Liping.
The previous versions of the standards replaced by this part are as follows.
---GB/T 6987.10-1986, GB/T 6987.10-2001;
---GB/T 20975.10-2008.
Chemical analysis methods of aluminum and aluminum alloys
Part 10.Determination of tin content
Warning---Personnel using this section should have practical experience in formal laboratory work. This section does not point out all possible safety issues
question. The user is responsible for taking appropriate safety and health measures and ensuring compliance with the conditions stipulated by relevant national laws and regulations.
1 Scope
This part of GB/T 20975 specifies the phenylfluorone spectrophotometric method and potassium iodate titration method for the determination of tin content in aluminum and aluminum alloys.
This section applies to the arbitration determination of tin content in aluminum and aluminum alloys. Phenylfluorone spectrophotometric measurement range. 0.0050%~
2.00%; potassium iodate titration method determination range. 0.35% ~ 55.00%.
The phenylfluorone spectrophotometric method in this section is not applicable to aluminum alloys with bismuth mass fraction > 0.20% or magnesium mass fraction > 4.0%.
Determination.
Note. When the mass fraction of tin is >0.35%~2.00%, the potassium iodate titration method is used as the arbitration method.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article
Pieces. For undated references, the latest version (including all amendments) applies to this document.
GB/T 8005.2 Terminology of Aluminum and Aluminum Alloy Part 2.Chemical Analysis
GB/T 8170-2008 Numerical rounding rules and the expression and determination of limit values
3 Terms and definitions
The terms and definitions defined in GB/T 8005.2 apply to this document.
4 Phenylfluorone spectrophotometry
4.1 Method summary
The sample was dissolved with sulfuric acid, and the tin in the residue was recovered by filtration. In a sulfuric acid medium, iron is reduced with ascorbic acid, and the animal glue solution is used as a dispersant.
Phenylfluorone is used to develop color, and its absorbance is measured at a wavelength of 510.0nm with a spectrophotometer to determine the tin content.
When the titanium mass fraction is greater than 0.015%, the same amount of titanium as the sample is added to the blank to offset its effect; when the zirconium mass fraction is greater than 0.015%,
Adding the same amount of zirconium to the blank to offset its effect.
4.2 Reagents
Unless otherwise stated, only reagents and laboratory secondary water confirmed to be analytically pure are used in the analysis.
4.2.1 Pure aluminum (wAl≥99.99%).
4.2.2 Sulfuric acid (ρ=1.84g/mL).
4.2.3 Hydrofluoric acid (ρ=1.14g/mL).
4.2.4 Hydrogen peroxide (ρ=1.10g/mL).
4.2.5 Sulfuric acid (4.0mol/L). Take 225mL sulfuric acid (4.2.2) and slowly pour into water, cool, dilute with water to 1000mL, and use hydrogen and oxygen
Calibration with sodium chloride solution (4.0mol/L).
4.2.6 Sulfuric acid (1 9).
4.2.7 Nitric acid (1 1).
4.2.8 Tartaric acid solution (50g/L).
4.2.9 Ascorbic acid solution (20g/L), prepared immediately when used.
4.2.10 Animal glue solution (2.5g/L), prepared immediately when used.
4.2.11 Phenylfluorone solution (0.3g/L). Weigh 0.300g of phenylfluorone and dissolve it in 500mL of absolute ethanol, add 30mL of sulfur
Acid (4.2.5), 20mL of water, place for one day, filter in a 1000mL volumetric flask, dilute to the mark with absolute ethanol, and mix.
4.2.12 Aluminum solution (2.5mg/mL). Weigh 0.6250g pure aluminum (4.2.1), place it in a 400mL beaker, cover with a watch glass, and add to the total
The amount is 24.5mL of sulfuric acid (4.2.5), heated to completely dissolved, and cooled. Transfer to a 250mL volumetric flask, dilute to the mark with water, and mix.
4.2.13 Tin standard storage solution. use a certified standard solution to prepare. Or weigh 0.2000g tin (wSn≥99.99%) and place it in
In a 100mL beaker, add 10.0mL sulfuric acid (4.2.2), heat to completely dissolve, continue to heat until white smoke is emitted, and cool. Add 25.0mL
Sulfuric acid (4.2.2), washed with sulfuric acid (4.2.6) into a 1000mL volumetric flask, diluted to the mark with sulfuric acid (4.2.6), and mixed. This solution 1mL
Contains 0.2mg tin.
4.2.14 Tin standard solution. Pipette 12.50mL tin standard stock solution (4.2.13) into a 500mL volumetric flask and dilute with sulfuric acid (4.2.6)
To the mark, mix well. 1mL of this solution contains 0.005mg tin.
4.2.15 Titanium solution. weigh 0.1000g titanium (wTi≥99.9%), place it in a 250mL beaker, add 50mL sulfuric acid (4.2.2) and heat to
Dissolve completely and cool down. Transfer to a 400mL beaker containing.200mL of water, after cooling, transfer to a 1000mL volumetric flask, dilute with water to
Scale and mix well. 1mL of this solution contains 0.1mg of titanium.
4.2.16 Zirconium solution. weigh 0.1000g zirconium (wZr≥99.9%), place it in a 250mL beaker, add 50mL sulfuric acid (4.2.2) and heat to
Dissolve completely and cool down. Transfer to a 400mL beaker containing.200mL of water, after cooling, transfer to a 1000mL volumetric flask, dilute with water to
Scale and mix well. This solution 1mL contains 0.1mg zirconium.
4.3 Apparatus
Spectrophotometer.
4.4 Sample
Process the sample into chips with a thickness of not more than 1mm.
4.5 Analysis steps
4.5.1 Sample
According to Table 1, weigh the sample (4.4) of the corresponding mass (m0) to the nearest 0.0001g.
4.5.2 Parallel test
Do two tests in parallel and take the average value.
4.5.3 Blank test
Weigh the corresponding mass of pure aluminum (4.2.1) according to Table 1, accurate to 0.0001g. Do a blank test with the sample. When the mass of titanium in the sample
When the number is greater than 0.015%, add the same amount of titanium solution as the sample (4.2.15). When the mass fraction of zirconium in the sample is >0.015%, add it with the sample, etc.
Amount of zirconium solution (4.2.16).
4.5.4 Determination
4.5.4.1 Place the sample (4.5.1) in a 100mL beaker and cover with a watch glass. Add sulfuric acid (4.2.5) according to Table 1, after the violent reaction stops,
Add a few drops of hydrogen peroxide (4.2.4) and slowly heat until the sample is completely dissolved. According to Table 1, filter with chronic quantitative filter paper in the corresponding volumetric flask
In (V0), wash the beaker and sediment with water 8 to 10 times.
4.5.4.2 Put the precipitate together with the filter paper in a platinum crucible, and after drying, it will be completely ashed at 500°C~600°C (don't let the filter paper ignite) and cool. plus
Add 5 to 6 drops of sulfuric acid (4.2.5), 2 mL of hydrofluoric acid (4.2.3), add nitric acid (4.2.7) to the solution until the solution is clear, heat and evaporate until there is no white smoke.
Burn at 700°C for several minutes and cool. Add a few drops of sulfuric acid (4.2.5), wash in a small amount of water, and heat until the residue is completely dissolved (filter if necessary).
The solution is combined in a volumetric flask (V0), diluted to the mark with water, and mixed.
4.5.4.3 Pipette the corresponding volume (V1) of the sample solution (4.5.4.2) into a 50mL volumetric flask and add sulfuric acid (4.2.5) according to Table 1.
2mL tartaric acid solution (4.2.8), 5mL ascorbic acid solution (4.2.9), 2mL animal glue solution (4.2.10), 2.5mL phenylfluorone
Solution (4.2.11). Dilute to the mark with water and mix well. Leave it for 40 minutes.
4.5.4.4 Move part of the sample solution (4.5.4.3) into the absorption cell, take the blank test (4.5.3) as the reference, and set the wavelength of the spectrophotometer at 510.0nm
Measure its absorbance. Find the corresponding tin mass (m1) from the working curve.
4.5.5 Drawing of working curve
4.5.5.1 Pipette 0mL, 0.50mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL tin standard solution (4.2.14) into a group of 50mL
In the volumetric flask, add 20.0mL aluminum solution (4.2.12), add 1.90mL, 1.60mL, 1.40mL, 1.00mL, 0.50mL and
0 mL sulfuric acid (4.2.5).
4.5.5.2 Add 2mL tartaric acid solution (4.2.8), 5mL ascorbic acid solution (4.2.9), and 2mL animal glue solution in the volumetric flask.
(4.2.10), 2.5 mL of phenylfluorone solution (4.2.11). Dilute to the mark with water and mix well. Leave it for 40 minutes.
4.5.5.3 Move part of the standard solution (4.5.5.2) into the absorption cell, take the reagent blank solution (without tin standard solution) as a reference,
The absorbance was measured at a wavelength of 510.0nm with a photometer. Use tin mass as the abscissa and absorbance as the ordinate to draw the working curve.
4.6 Test data processing
The tin content is calculated as the tin mass fraction wSn, calculated according to formula (1).
4.7 Precision
4.7.1 Repeatability
The measured value of two independent test results obtained under repeatability conditions, within the average range given below, the two test results
The absolute difference does not exceed the repeatability limit r, and the case of exceeding the repeatability limit r does not exceed 5%. Repeatability limit r uses linear interpolation according to the data in Table 2
Law to get.
4.7.2 Reproducibility
The measured values of two independent test results obtained under reproducibility conditions, within the average range given below, the two test results
The absolute difference does not exceed the reproducibility limit R, and the case of exceeding the reproducibility limit R does not exceed 5%. Reproducibility limit R According to the data in Table 3, the linear internal
Get it by interpolation.
5 Potassium iodate titration method
5.1 Method summary
The sample is decomposed with sulfuric acid and hydrofluoric acid. In hydrochloric acid and sulfuric acid solutions, iron powder and aluminum flakes are used as reducing agents, starch is used as indicator, and iodic acid is used
Potassium standard titration solution titration test solution is light blue as the end point to determine the tin content.
5.2 Reagents
Unless otherwise stated, only reagents and laboratory secondary water confirmed to be analytically pure are used in the analysis.
5.2.1 Iron powder (wFe≥99%, wSn≤0.001%).
5.2.2 Aluminum sheet (wAl≥99.7%, wSn≤0.001%).
5.2.3 Sulfuric acid (ρ=1.84g/mL).
5.2.4 Hydrofluoric acid (ρ=1.14g/mL).
5.2.5 Hydrogen peroxide (ρ=1.10g/mL).
5.2.6 Hydrochloric acid (11).
5.2.7 Sulfuric acid (1 1).
5.2.8 Saturated sodium bicarbonate solution.
5.2.9 Tin standard solution (c0=1mg/mL). Use a certified standard solution to prepare. Or weigh 0.5000g tin (wSn≥
99.99%), put in a 250mL beaker, add 20mL sulfuric acid (5.2.3), cover with a watch glass, heat until tin is completely dissolved, cool, add water
20mL, shake while adding. Slowly add 100mL hydrochloric acid (5.2.6) to dissolve the salts, after cooling, transfer the solution into 500mL with hydrochloric acid (1 4)
Dilute to the mark in a volumetric flask and mix well.
5.2.10 Potassium iodate standard titration solution A [c1(1/6KIO3)≈0.01mol/L].
---Preparation. Weigh 0.36g potassium iodate, 9g potassium iodide, 0.3g sodium hydroxide into a 500mL beaker, add.200mL water, add
Heat to completely dissolve, filter the solution in a 1000mL volumetric flask with glass wool, dilute to the mark with water, and mix well.
---Calibration. Pipette 3 volumes (V2) into 25.00mL tin standard solution (5.2.9), put them into 500mL conical flasks and add
40mL sulfuric acid (5.2.7), the following operations are carried out according to 5.4.4.4~5.4.4.5.The potassium iodate standard titration solution consumed for parallel calibration
The range of the volume of liquid A (5.2.10) should not be more than 0.10mL, whichever is the average value (V3).
At the same time, use another 500mL Erlenmeyer flask containing 50mL water to do a blank test, and record the potassium iodate standard consumed in the titration
Titrate the volume (V4) of solution A (5.2.10).
---Calculation. Calculate the actual concentration of potassium iodate standard titration solution according to formula (2).
The calculation result retains four significant figures. The rounding of values shall be implemented in 3.2 and 3.3 of GB/T 8170-2008.
5.2.11 Potassium iodate standard titration solution B[c2(1/6KIO3)≈0.05mol/L].
---Preparation. Weigh 1.81g potassium iodate, 9g potassium iodide, 0.3g sodium hydroxide into a 500mL beaker, add.200mL water, add
Heat to completely dissolve, filter the solution in a 1000mL volumetric flask with glass wool, dilute to the mark with water, and mix well.
---Calibration. Pipette 3 parts with a mass (m2) of 0.1000g tin (wSn≥99.99%), put them in a 500mL conical flask, and add 20mL
Sulfuric acid (5.2.3) is heated until it emits thick white smoke to completely dissolve the metal tin, remove, cool, blow along the bottle wall and add 50mL water,
Follow 5.4.4.4~5.4.4.5 to operate. The volume of potassium iodate standard titration solution B (5.2.11) consumed in parallel calibration
The range should not be greater than 0.15mL, whichever is the average value (V5).
At the same time, use another 500mL Erlenmeyer flask containing 50mL water to do a blank test, and record the potassium iodate standard consumed in the titration
Titrate the volume (V6) of solution B (5.2.11).
---Calculate the actual concentration of potassium iodate standard titration solution according to formula (3).
5.2.12 Starch solution A (5g/L). Weigh 0.5g soluble starch into a 250mL beaker, add 100mL boiling water, stir, boil,
Cooling (prepared when used).
5.2.13 Starch solution B (5g/L). Weigh 0.5g soluble starch into a 250mL beaker, add 100mL boiling water, stir, boil,
Cool, add 3g potassium iodide, stir to dissolve, and mix (prepared when used).
5.3 Specimen
Process the sample into chips with a thickness of not more than 1mm.
5.4 Analysis steps
5.4.1 Sample
According to Table 4, weigh a sample (5.3) of a certain mass (m3) to the nearest 0.0001g.
Table 4
5.4.2 Parallel test
Do two tests in parallel and take the average value.
5.4.3 Blank test
Do a blank test with the sample (5.4.1). Record the volume (V8) of the potassium iodate standard titration solution (5.2.10 or 5.2.11) consumed.
5.4.4 Determination
5.4.4.1 Place the sample (5.4.1) in a 250mL polytetrafluoroethylene beaker.
5.4.4.2 Add a little water, slowly add 40mL sulfuric acid (5.2.7), after the violent reaction stops, heat until the sample is completely dissolved, add a few drops
Hydrogen peroxide (5.2.5). Slowly add 20mL of hydrofluoric acid (5.2.4) in portions, continue to heat until sulfuric acid fumes, remove and cool. Blow the cup with water
The wall is heated again to emit sulfuric acid fumes, which can be repeated 1 to 2 times, and then removed and cooled. Purge the wall of the cup with water and add 25mL of water.
5.4.4.3 When the mass fraction of copper in the sample is less than or equal to 1.00%, add 100 mL of hydrochloric acid (5.2.6), heat to dissolve the salts, and add 1 g of iron powder (5.2.1),
Heat to dissolve the iron powder. After cooling, use a small amount of hydrochloric acid (5.2.6) to transfer the solution to a 500mL conical flask, and add water to the sample solution volume approximately
150mL. When the mass fraction of copper in the sample is >1.00%, add 100mL hydrochloric acid (5.2.6), 1g~2g iron powder (5.2.1), and heat to boil slightly
When the precipitate has agglomerated and a small amount of iron powder remains, cool slightly, filter it in a 500mL conical flask with quick filter paper, and wash the beaker and sink with hydrochloric acid (5.2.6).
Dip 6 to 7 times, add water to the sample solution volume about 150mL.
5.4.4.4 Add 2g aluminum flakes (5.2.2), after the violent reaction calms down, cover the Geishi funnel with saturated sodium bicarbonate solution (5.2.8), add
Heat and boil for a few minutes to completely dissolve the aluminum sheet, remove it, cool it to room temperature with running water, and replenish the saturated sodium bicarbonate solution at any time during the cooling process
(5.2.8) to isolate the air.
5.4.4.5 Remove the Geishler funnel, pour a little bit of the saturated sodium bicarbonate solution (5.2.8) retained in the Geishler funnel into the Erlenmeyer flask.
Quickly add 5mL starch solution (5.2.12 or 5.2.13), add 5mL starch solution B (5.2.13) to the blank test solution, and immediately use iodic acid
The potassium standard titration solution (5.2.10 or 5.2.11) titration solution is just light blue as the end point. Record the consumption of potassium iodate standard titration solution (5.2.10
Or 5.2.11) volume (V7).
5.5 Test data processing
The tin content is calculated as the tin mass fraction wSn, calculated according to formula (4).
5.6 Precision
5.6.1 Repeatability
The measured value of two independent test results obtained under repeatability conditions, within the average range given below, the two test results
The absolute difference does not exceed the repeatability limit r, and the case of exceeding the repeatability limit r does not exceed 5%. Repeatability limit r uses linear interpolation according to the data in Table 5
Method or extension method.
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