This standard is applicable to the determination of phosphorus content in nickel-based alloy powder. Determination range: 0.001% to 0.05%. This standard complies with GB 1467-78 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". GB/T 8638.12-1988 Chemical analysis method for nickel-based alloy powder - n-butanol-chloroform extraction spectrophotometric method for determination of phosphorus content GB/T8638.12-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method for nickel base alloy powder
N-butyl alcohol-chloroform extraction spectrophotometric method
Nickel base alloy powder-- Determination of phosphorus content N-butyl alcohol-chloroform extraction spectrophotometric method This standard is applicable to the determination of phosphorus content in nickel base alloy powder. Determination range: 0.001%～0.05%. UDC 669. 245-492. 2
GB 8638.12--88
This standard complies with GB146778 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
The sample is dissolved in acid. In the nitric acid medium, the phosphomolybdic acid generated by orthophosphoric acid and ammonium molybdate can be extracted by n-butanol-chloroform. The phosphomolybdic acid is reduced with stannous chloride and extracted back into the water phase. Its absorbance is measured at a wavelength of 680nm on a spectrophotometer. 2 Reagents
Sodium hydroxide, high-grade purity.
2.2 Hydrochloric acid (p1.19g/mL).
2.3 Nitric acid (p1.42 g/mL).
Hydrofluoric acid (p1.15g/ml).
Perchloric acid (p1.67g/mL).
2.6 Ammonium molybdate solution (10%).
Sodium nitrite solution (30%).
Nitric acid (1+1): Boil nitric acid (2.3) for 3~5min to drive out all nitrogen oxides before preparing. 2.8www.bzxz.net
2.9 Citric acid solution (10%), prepared with an aqueous solution containing 3.5g of sodium hydroxide per 100mL of solution. 2.10
n-Butanol-chloroform mixture: mix one part of n-butanol with three parts of chloroform. Stannous chloride solution (1%): dissolve 1g of stannous chloride (SnCl2H0) in 8mL of hydrochloric acid (2.2), dilute with water to 2.11
100mL, prepare it when used.
2.12 Phosphorus standard stock solution: weigh 0.2195g of potassium dihydrogen phosphate that has been dried at 105~110℃ in advance, dissolve it in water, add 10mL of nitric acid (2.3), transfer it to a 1000mL volumetric flask, dilute to the mark with water, mix well, and store in a plastic bottle. This solution contains 50ug of phosphorus in 1mL.
2.13 Phosphorus standard solution: Pipette 20.00mL of phosphorus standard storage solution (2.12) into a 1000mL volumetric flask, add 5mL of nitric acid (2.3), dilute to the mark with water, and mix well. This solution contains 1μg of phosphorus in 1mL. 3 Instruments
Spectrophotometer.
Approved by China National Nonferrous Metals Industry Corporation on January 11, 1988 212
Implemented on January 1, 1989
4 Analysis steps
4.1 Number of determinations
Measure twice in parallel and take the average value.
4.2 Sample quantity
Weigh 0.1000g to 0.5000g of sample.
4.3 Blank test
Carry out a blank test with the sample.
4.4 Determination
GB 8638. 12- 88
4.4.1 Place the sample (4.2) in a 150 mL conical flask, add a mixture of hydrochloric acid (2.2) and nitric acid (2.3) in an appropriate proportion, heat to dissolve, and add hydrofluoric acid (2.4) to dissolve the insoluble sample. 4.4.2 Add 5-10 mL perchloric acid (2.5), heat and evaporate until smoke appears, oxidize chromium to hexavalent, add 2-3 mL hydrochloric acid (2.2) to evaporate most of the chromium, continue to evaporate until nearly dry, and cool. Add 15mL nitric acid (2.8), heat to dissolve salts, drop sodium nitrite solution (2.7) to reduce high-valent chromium to low-valent [add 6mL citric acid solution (2.9) to the tungsten-containing sample, add 9mL for 10-20mg tungsten, add sodium hydroxide (2.1) until the solution is alkaline, heat to dissolve tungstic acid, drop nitric acid (2.8) until the solution is acidic, cool], transfer to a 100mL volumetric flask, dilute to scale with water, and mix.
4.4.3 Transfer 20mL of the test solution (4.4.2) to a 125mL separatory funnel, add nitric acid (2.8) until the solution contains 8mL nitric acid (2.8).
4.4.4 Dilute with water to about 45mL, add 20mL of n-butanol-chloroform mixture (2.10), 12mL of ammonium molybdate solution (2.6) (if 9mL of citric acid solution (2.9) is added to the test solution, 18mL of ammonium molybdate solution (2.6) should be added), and immediately shake vigorously for 1min. After the two phases are separated, put the organic phase into another separatory funnel containing 15mL of stannous chloride solution (2.11), shake gently 15 times, and after the two phases are separated, transfer the aqueous phase into a 2-3cm colorimetric blood.
4.4.5 Using water as a reference, measure its absorbance at a wavelength of 680nm on a spectrophotometer, subtract the absorbance of the blank sample, and find the corresponding phosphorus amount from the working curve.
4.5 Drawing of working curve
4.5.1 Take 0, 1.00, 3.00, 5.00, 7.00, 10.00mL of phosphorus standard solution (2.13) and place them in 125mL separatory funnels respectively, add 8mL of nitric acid (2.8), and proceed as in 4.4.2. 4.5.2 Take water as reference, measure its absorbance at 680nm wavelength on spectrophotometer, subtract the absorbance of reagent blank, and draw working curve with phosphorus content as abscissa and absorbance as ordinate. 5 Calculation of analysis results
Calculate the percentage of phosphorus according to formula (1):
Where: m,
P(%) = m, ×V.×10-
Phosphorus content pg obtained from standard curve;
Volume of test solution, E;
V. —Total volume of test solution, mL;
m. -~Weighing amount, g.
6Permissible difference
The difference in analysis results between laboratories should not be greater than the permissible difference listed in Table 1. (1)
Additional remarks:
Phosphorus content
0.0010~0.0050
>0.005~0.010
≥0. 010~0. 030
0. 030~0. 050
GB8638.12-88
This standard was drafted by the Central Iron and Steel Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Central Iron and Steel Research Institute of the Ministry of Metallurgical Industry. The main drafter of this standard is Yang Qiuping.
Permissible difference
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