This standard specifies the determination of phosphorus content by bismuth phosphorus 1k1 blue spectrophotometry. This standard is applicable to the determination of phosphorus content in ferrosilicon. Determination range: 0.010% to .060% GB/T 4333.2-1988 Chemical analysis method for ferrosilicon - Determination of phosphorus content by bismuth phosphorus molybdenum blue spectrophotometry GB/T4333.2-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of ferrasiliconThe reduced molyhdobismuthylphospborie aeldpboionctrie methad for the determinailon of phasphorus content1Subject content and scope of application
This standard specifies the determination of phosphorus content by phospho-saw blue spectrophotometry. This standard is applicable to the determination of phosphorus content in ferrosilicon, with a determination range of 0.010% to 0.060%. 2 Method Summary
UDC 669. 15' 782
:543.42:546
GB 4333.2-88
GD4333.2-84
The sample is dissolved with nitric acid and hydrofluoric acid. Perchloric acid produces smoke. Arsenic is reduced with sodium thiosulfate. In the presence of bismuth salt, ascorbic acid-acetylase solution is used to reduce bismuth phosphocyanate blue. Its absorbance is measured at a wavelength of 690 on a spectrophotometer. 3 Reagents
3. 1 Nitric acid (μ1. 42 g/L).
3. 2 Hydrofluoric acid (p1. 15 g/L).
3.3 Perchloric acid (p1. 67 /L).
3.4 ​​Perfluoric acid (1/3).
3.5 Ammonium molybdate solution (40g/L): Weigh 4g ammonium molybdate ((NHL)6Mo, 0g*4H20). Place in a 200mL beaker, add 100mL water, and dissolve evenly in warm water.
3.6 Bismuth nitrate solution (10g/L): Weigh 1g bismuth nitrate, place in a 200mL beaker, add 50mL nitric acid (3.1), wait until it is completely dissolved, add 50mL water, and mix evenly.
3.7 Sodium thiosulfate solution (5z/L): Weigh 18 anhydrous sodium sulfite and 0.5g sodium thiosulfate (NaS: 0g·5H;0), place in the same beaker, add a small amount of water to dissolve, transfer to a 100mL volumetric flask, dilute to the mark with water, and mix evenly. 3.8 Ascorbic acid-ethanol solution (10B/L), weigh 3g ascorbic acid, place in a 400ml beaker, add 100mL water to dissolve, add 20mL ethanol, mix.
3. 9 Phosphorus standard solution;
3.9-1 Weigh 0.1391 potassium dichlorophosphate standard reagent that has been pre-dried at 105C for 1h and cooled to room temperature in a desiccator, place in a 400mL beaker, dissolve with water, add 2mL nitric acid (3.1), transfer to a 1000mL volumetric flask, dilute to scale with water, and mix. This solution contains 100g phosphorus in 1mL.
3.9.2 Transfer 25.00ml. Phosphorus standard solution (3.9.1), place in a 500mL volumetric flask, dilute to scale with water, and mix. This solution contains 1mL phosphorus.
4 Sample
The sample should pass through a 0.125 mm sieve
Approved by the Ministry of Metallurgical Industry of the People's Republic of China on September 8, 1988 and implemented on January 1, 1990
5 Analysis steps
5.1 Sample quantity
Weigh 0.3000 g of sample.
5.2 Empty test
Carry out an empty test together with the sample.
5.3 Determination
GB 4333-2-88
5.3.1 Place the sample (5.1) in a platinum or polytetrafluoroethylene beaker, add 15 mL nitric acid (3.1), add 3~5 mL hydrochloric acid (3.2) while shaking until the sample is completely dissolved, add 10 mL perchloric acid (3.3), heat on a hot plate until white smoke appears, and concentrate to a volume of about 3 ml. Remove the flask.
5.3.2 Add 30 mL hot water, heat to dissolve the salts, filter with rapid quantitative filter paper into a 100 mL volumetric flask, wash the beaker and filter paper with hot water 4~5 times each, cool to room temperature, dilute with water to the mark, and mix. Transfer 20.00 mL of the solution and place it in a 100 mL beaker. 5.3.3 Add 5 mL of perfluoric acid (3.4), evaporate on a low-temperature electric hot plate to a volume of about 1 mL, remove and cool slightly, rinse the cup wall with water, control the solution volume to about 10 mL, and heat to dissolve the salts. Remove and cool. Transfer to a 50 mL volumetric flask. 5.3.4 Add 1 ml of sodium thiosulfate solution (3.7), 5 mL of bismuth nitrate solution (3.6), 5 mL of ammonium sulfate solution (3.5), and 15 mL of ascorbic acid-ethanol solution (3.8). Mix immediately after adding each reagent. Dilute with water to the scale and mix. Let stand for 2 minutes (if the room temperature is 15, let stand for 10 minutes).
5.3.5 Transfer part of the solution into a 2 cm colorimetric tube and measure its absorbance at a wavelength of 690 nm using the blank test solution nebulizer ratio that is included with the sample on a spectrophotometer. Find the corresponding phosphorus content from the working curve. 5.4 Drawing of working curve
Take 0, 1.00, 2.00, 4.00, 5.00mL of phosphorus standard solution (3.9.2) and place them in a group of 100mL beakers respectively. Dilute to 20mL with water. The following is carried out according to 5.3.3 and 5.3.4. Transfer part of the dissolved solution into 2cm colorimetric blood, use the reagent blank as reference, and measure its absorbance at a wavelength of 690nm on the spectrophotometer. Draw the working curve with phosphorus content as the horizontal axis and absorbance as the vertical axis. 6 Calculation of analysis results
Calculate the percentage of phosphorus according to the following formula:
In the formula: Zhu——Phosphorus content found from the working curve; V——Total volume of test solution, mL
—Volume of test solution taken, mL,
m—Sample volume, g.
7 Tolerance
The difference between the analysis results of laboratories should not exceed the tolerance listed in the following table. Additional remarks:
0.010---0.030
≥ 0,030-~0.060bzxZ.net
CB 4333. 2--88
This standard was drafted by Panzhihua Iron and Steel Research Institute of the Ministry of Metallurgy. The chief drafter of this standard is Ma Shuping.
The level mark of this standard
0B4833.2-881
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