This standard specifies the determination method of iron content in industrial silicon. This standard is applicable to the determination of iron content in industrial silicon. Determination range: 0.10% to 1.20%. GB/T 14849.1-1993 Chemical analysis method for industrial silicon 1,10--Phenanthroline spectrophotometric method for determination of iron content GB/T14849.1-1993 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method for industrial silicon
1, 10-phenanthroline spectrophotometric method for determination of iron contentSilicon metal-Determination of iron content---1, 10-Phenanthroline spectrophotometric method1 Subject content and scope of application
This standard specifies the method for determination of iron content in industrial silicon. This standard is applicable to the determination of iron content in industrial silicon. Determination range: 0.10%~1.20%. 2 Reference standards
GB1.4 Guide to standardization work Provisions for the preparation of chemical analysis methods GB1467 General provisions for chemical analysis methods for metallurgical products GB7729 General rules for spectrophotometric methods for chemical analysis of metallurgical products 3 Basic requirements for preparation
This standard is prepared in accordance with the provisions of GB1.4, GB1467 and GB7729. 4 Principle of the method
GB/T 14849.1-93
The sample is decomposed with fluoric acid and nitric acid, and silicon, fluorine, etc. are driven off by sulfuric acid fuming. The residual is dissolved by hydrochloric acid, and (III) is reduced to Fc (1) by hydrochloric acid amine. In a slightly acidic medium of nH3~~5, iron and 1.10 fluorine impurities form a red complex, and its absorbance is measured at a wavelength of 510nn by a spectrophotometer.
5 Reagents
5.1 Hydrofluoric acid (gl.14g/ml.).
5.2 Nitric acid (1+1). bzxZ.net
5.3 Sulfuric acid (1+1)
5.4 Hydrochloric acid (1+1)
5.5 Hydroxylamine hydrochloride solution (10g/l).
5.6 1,10-phenanthroline solution (2.5 g/L): weigh 1.25 g 1,10-phenanthroline (C121N·0) in a beaker, add 2 ml hydrochloric acid (5.4), add about 300 ml water, dilute to 500 ml with water. 5.7 Sodium acetate buffer solution: weigh 272 ml sodium acetate (CH.CO0Na·3H20) in a beaker, add 500 ml water, float and filter, put into a 100 ml volumetric flask, add 240 ml glacial acetic acid (p1.05 g/ml), dilute to scale with water, mix well. 5.8 Mixed color development solution: pipette 1 unit volume of hydroxylamine disodium solution (5.5), 1 unit volume of 1,10-phenanthroline solution (5.6), 2 unit volumes of acetic acid-sodium acetate buffer solution (5.6), mix, and use within one week. 5.9 Iron standard stock solution: weigh 0.2a60g of ferric cyanide that has been previously burned at 600C for 1h and cooled to room temperature in a desiccator. Place it in a beaker, add 30mL of hydrochloric acid (5.4), heat at low temperature to dissolve, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and mix. This solution contains 200μg of iron in 1mL.
5.10 Iron standard solution: transfer 50.00mL of iron standard stock solution (5.9) into a 200mL volumetric flask, dilute to scale with water, and mix. This solution contains 50ug of iron in 1mL.
6 Instruments
Spectrophotometer.
7 Analysis steps
7.1 Sample
The sample particle size passes through a 0.149mm sieve diameter, and the iron powder is sucked out with a magnet. 7.2 Sample
Weigh 1.0000 g of sample (7.1).
7.3 Blank test
Carry out a blank test along with the sample.
7.4 Determination
7.4.1 Place the sample (7.2) in a 100mL platinum dish, add 0.5mL sulfuric acid (5.3), 20~25mL hydrofluoric acid (5.1), and drop nitric acid (5.2) in portions until most of the sample is dissolved, move the platinum dish to a sand bath, heat until the sample is completely dissolved, and evaporate to dryness. 7.4.2 Place platinum III in a high-temperature furnace at 450±25℃, until all sulfuric acid fumes are gone, take it out, and cool it. 7.4.3 Add 5.0mL hydrochloric acid (5.4) to the platinum group, add 20~~30mL water along the blood wall, heat until the residue is completely dissolved, and cool. 7.4.4 Transfer to a 500mL volumetric flask, dilute to the mark with water, and mix. 7.4.5 Transfer the test solution (7.4.4) according to Table 1 and place it in a 100mL volumetric flask. Table 1
Iron content, %
0.10~0.20
>0.20~0.80
>0. 80~1.20
Transfer test solution volume, ml
7.4.6 Add 20mL mixed color development solution (5.8), dilute to the mark with water, and mix. Let stand for 15 minutes. 7.4.7 Transfer part of the solution (7.4.6) into 1cm absorption III, and measure its absorbance at a wavelength of 510nm on a spectrophotometer with water as reference.
7.4.8 Subtract the absorbance of the blank test solution and find the corresponding mass of iron from the working curve. 7.5 Drawing of working curve
7.5.1 Transfer 0.00, 1.00, 2.00, 4.00. 6.00, 8.00mL of the iron standard solution (5.10) and place them in -100ml volumetric flasks respectively.
7.5.2 Add a blank test solution (7.3) equal to the volume of the transferred test solution according to Table 1, and proceed as follows in 7.4.6 and 7.4.7. 7.5.3 Subtract the absorbance of the blank test solution and draw a curve with the mass of iron as the abscissa and the absorbance as the ordinate. 8 Expression of analysis results
Calculate the percentage of iron by the following formula:
Fe(%) = m V. X 10 6
GB/T 14849.1---93
-The mass of iron found from the working curve, μg; Where: mi\-
V. Total volume of test solution.mL:
V,—Volume of test solution transferred.ml.;
9 Allowable difference
The mass of the sample, g.
The difference of analysis results between laboratories should not be too big. The allowable difference in Table 2, Table 2
0.100~-0.300
20. 300~~ 0. 650
*0. 650~-0, 900
0. 920~1. 200
Additional remarks:
This standard is proposed by China Nonferrous Metals Industry Corporation. This standard is drafted by Fushun Aluminum Factory.
This standard is drafted by Fushun Lead Guang and China Nonferrous Metals Corporation Standard Metrology Research Institute. The main drafters of this standard are Yu Min and Ma An.
Official From the date of implementation of this standard, the "Chemical Analysis Method for Industrial Residues" YB95--76 issued by the former Ministry of Metallurgical Industry of the People's Republic of China will be invalid.
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