GB/T 4103.4-2000 Chemical analysis methods for lead and lead alloys - Determination of iron content
Some standard content:
GB/T4103.4-2000
This standard is a revision of (GB/T4103.6-:1983 "Chemical analysis method of lead-based alloys - o-phenanthroline photometric method for determination of iron content" and CB/T472.8-1984 "Chemical analysis method of lead ingots - o-phenanthroline spectrophotometric method for determination of iron content". This standard complies with:
GB/T 1.1:-1993
Guidelines for standardization work
Basic provisions
Unit 1: Rules for drafting and expressing standards Part 1: 3 Guidelines for standardization work for standard writing
Regulations for the preparation of chemical analysis methods standards
GB/T 1. 4-1988
GB/T14671978 General principles and general provisions of the standard for chemical analysis methods of metallurgical products GB/T7729--1987 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB/T17433-1998 Basic terminology for chemical analysis of metallurgical products This standard replaces GB/T4103.6-1983.GB/T472.8--1984 from the date of entry into force. This standard was proposed by the State Bureau of Nonferrous Metals Industry . This standard is under the jurisdiction of China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard was drafted by Shenyang Smelter and Northwest Copper Processing of Baiyin Nonferrous Metals Company. This standard was drafted by Baiyin Nonferrous Metals Company. The main drafters of this standard are: Han Huanping, Guan Guanghua, Zhang Yuequn. 117
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of lead and lead alloys
Determination of iron content
Methods for chemical analysis of lead and lead alloys--Determination of iron content This standard specifies the method for determination of iron content in lead and lead alloys. GB/T 4103. 42000
Replaces GB/T 4103.61983
GB/T 172.8 1981
This standard is applicable to the determination of iron content in lead and lead alloys. Determination range: 0.00030%~).012%. 2 Method Summary
The sample is dissolved in mixed acid, Na?EDTA is added to complex lead and eliminate interference from other elements, sodium thiosulfate is used to mask interference from silver, selenium, and tellurium, and stannous chloride is used to reduce them to monomers and remove them by filtration. In sodium acetate buffer solution, hydroxylamine hydrochloride is used to reduce trivalent iron to divalent iron to form a red complex with 1,10-diazanon, and its absorbance is measured at a wavelength of 510nm on a spectrophotometer. 3 Reagents
3.1 Hydrochloric acid (p1.19g/mL), high-grade purity. 3.2 Hydrochloric acid (1+2), high-grade purity.
3.3 Hydrochloric acid (1+9), high-grade purity.
3.4 Ammonia nitrogen water (1+1), high-grade purity.
3.5 Mixed acid: weigh 30g tartaric acid and dissolve it in 80mL nitric acid (1+4), dilute it to 100mL with nitric acid (1+4), mix well, 3.6 Anhydrous sodium acetate solution (250g/L). 3.7 Sodium thiosulfate solution (200g/L). 3.8 Hydroxylamine hydrochloride solution (100g/1.). 3.9 Stannous chloride solution (200g/L): weigh 20g stannous chloride (SnCl2·2Hz0), dissolve it in 80mL hydrochloric acid (3.2), dilute it to 100mL with hydrochloric acid (3.2), mix well.
3.10 Disodium ethylenediaminetetraacetate (NazEDTA, high-grade pure) solution (230g/L): Weigh 230g NazEDTA (C..HN0,Na·2H,O) and dissolve it in 600mL ammonium hydroxide (1+5), dilute with water to 1000mL, and mix well. 3.111.10-Phenanthroline (C12HgN2*Hz0) ethanol solution (12.5m/L). 3.12 Tellurium nitrate solution (2g/L): Weigh 0.500g pure tellurium and place it in a 250ml beaker, add 20ml nitric acid (1/1), heat until it is completely dissolved, boil to remove nitrogen oxides, and cool. Transfer to a 250mL volumetric flask, dilute with water to the mark, and mix. 3.13 Iron standard stock solution: Weigh 0.1000g of pure iron into a 250mL beaker, add 20ml of nitric acid (1+1), heat until the dust is completely dissolved, boil to remove nitrogen oxides, and cool. Transfer to a 1000ml volumetric flask, dilute to scale with water, and mix well: 1ml of this solution contains 100 μg of iron.
3.14 Iron standard solution: Transfer 10.00mL of iron standard stock solution (3.13) into a 100ml volumetric flask. Add 2ml of nitric acid (11), dilute to scale with water, and mix well. 1mL of this solution contains 10ug of iron. Approved by the State Administration of Quality and Technical Supervision on August 28, 2000 118
Implementation on December 1, 2000
4 Instruments
Spectrophotometer.
5 Analysis steps
5.1 Test sample
5.1.1 Pure lead and lead alloys without selenium and tellurium
Weigh the sample according to Table 1, accurate to 0.0001g. Iron content%
0. 000 30~ 0. 003 0
>0. 003 0~0. 012
5.1.2 Lead alloys containing selenium and tellurium
GB/T4103.4—2000
Test sample amount,
Weigh 2.000g sample, accurate to 0.0001g. Perform 2 independent measurements and take the average value. 5.2 Blank test
Perform a blank test with the test sample.
5.3 Determination
5.3.1 Dissolution and separation of samplesbzxz.net
5.3.1.1 Pure lead and lead alloys without selenium and tellurium are added with Na.EDTA solution.
Put the sample (5.1.1) in a 250ml beaker, add 10mL of mixed acid, cover with table III, heat at low temperature to dissolve completely, boil to remove nitrogen oxides, wash the table and beaker with a small amount of water, and cool. Transfer to a 50mL volumetric flask, add Na2EDTA solution according to table 1, mix 5.3.1.2 Lead alloy containing selenium and tellurium
Put the sample (5.7.2) in a 250mL beaker, add 20mL of mixed acid, cover with table III, heat at low temperature to dissolve completely. Boil to remove nitrogen oxides. If there is black residue, evaporate the solution until salts are precipitated. Add 20mL water and 15mL hydrochloric acid (3.1), continue heating, and boil slightly until the precipitate condenses. Remove and cool to room temperature, and let stand. Transfer the supernatant to a 250mL beaker, and wash the beaker and precipitate 4 to 5 times with hydrochloric acid (3.3) by pouring method, and discard the precipitate. Combine the supernatants from each time, slowly heat and evaporate until viscous, add 5mL hydrochloric acid (3.1), and evaporate until viscous. Add 10mL nitric acid solution and 5mL hydrochloric acid (3.1), and evaporate again until viscous. Add 20mL hydrochloric acid (3.2), heat until the salts are dissolved, add 5mL stannous chloride solution, and boil until the precipitate condenses. Remove and cool, filter with medium-speed quantitative filter paper, wash the beaker and precipitate 5 to 6 times with hydrochloric acid (3.3), and discard the precipitate. Collect the filtrate and washing liquid in a 50mL container, dilute to the mark with hydrochloric acid (3.3), and mix well. Pipette 10.00ml of the solution into a 50ml volumetric flask, add 5ml of NazEDTA solution and mix. 5.3.2 Color development
5.3.2.1 Adjust the pH value of the solution to about 6 with hydrochloric acid (3.2) and ammonia water, add 5ml of sodium acetate solution, stir, test the wave to see if there is silver, add 2.5ml of sodium thiosulfate solution and mix. 5.3.2.2 Add 2ml of hydroxylamine hydrochloride solution and 3ml of 1,10-diazepine solution and mix. Heat the solution in a 40(±5(water bath) for 3 min, remove and cool to room temperature, dilute to scale with water and mix. 5.3.3 Measurement
Transfer part of the solution into a 2cm or 5cm absorption III, use the blank solution of the sample as a reference, measure its absorbance at a wavelength of 510nm with a spectrophotometer, and find the corresponding iron content from the working curve. 5.4 Drawing the curve
GB/T4103.4-2000
5.4.1 Working curve of iron content 0.00030%~0.0030% 5 .4.1.1 Take 0.0.25, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 mL of the standard iron solution and place them in 50 mL volumetric flasks respectively. Add 5 mL of Na2EDTA solution and mix well. The following is carried out according to 5.3.2. 5.4.1.2 Transfer part of the solution into a 5 cm absorbent tube and measure its absorbance at a wavelength of 510 nm with a ten-minute photometer using the reagent blank as a reference. Draw a working curve with the iron content as the horizontal axis and the absorbance as the vertical axis. 5.4.2 Iron content 0.0030%~~0.012% working curve 5.4.2.1 Take 0, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00 ml of iron standard solution and place them in 50 ml bottles respectively, add 5 ml of Na, EDTA solution to each bottle and mix well. The following is carried out according to 5.3.2. 5.4.2.2 Transfer part of the solution into 2 cm absorption blood, use the reagent blank as reference, measure its absorbance at a wavelength of 510 nm on the spectrophotometer, and draw the working curve with the iron content as the horizontal axis and the absorbance as the vertical axis. Expression of analysis results
Calculate the white content of iron according to formula (1):
Where: m
mz. V. X10-6
Fe(%) =
The amount of iron found from the working curve, g;
The total volume of the test solution, mL;
The volume of the test solution taken out of the fraction, mL;
The mass of the test material + the mass of the sample.
The result is expressed to three decimal places. If the iron content is less than 0.010%, it is expressed to four decimal places; if it is less than 0.0010%, it is expressed to five decimal places.
Allowable difference
The difference between the analysis results of the laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Iron content
0. 000 30~0. 000 60
0. 000 60~0. 001 5
0. 001 5 ~ 0. 003 0
0. 003 0 ~0. 006 0
2 0. 006 0~0. 012
Allowance
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