GB/T 15076.13-1994 Chemical analysis method of tantalum and niobium - Determination of nitrogen content in tantalum
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method of molybdenum saw
Determination of nitrogen content in tantalum
Methods for chemical analysis of tantalum and niobium-Determinationof nitrogen content in tantalum Part I Method 1 Distillation separation
1 Subject content and scope of application
This standard specifies the method for the determination of nitrogen content in molybdenum. GB/T 15076.13—94
Nessler reagent spectrophotometry
This standard is applicable to the determination of nitrogen content in molybdenum. Determination range: 0.002% to 0.02%. 2 Reference standards
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis methods GB1467 General principles and general provisions for chemical analysis methods for metallurgical products GB7729 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Principles of the method
The sample is dissolved in acid, nitrogen forms ammonium salt, and the alkaline solution is distilled. The distillate is absorbed in sulfuric acid solution, and after color development with Nessler reagent, its absorbance is measured at a wavelength of 420nm on a spectrophotometer. 4 Reagents
The water used in this standard is ammonia-free water.
Sulfuric acid (p1.84g/mL), high-grade pure.
4.2 Hydrofluoric acid-hydrochloric acid mixed acid: 3 units of hydrofluoric acid (high-grade pure) are mixed with 1 unit of hydrochloric acid (high-grade pure). 4.3 Boric acid solution (200g/L), heat and dissolve before use. 4.4 Sodium hydroxide solution (500g/1.): Weigh 500g sodium hydroxide (superior purity), dissolve in 1000mL water, add 0.5g zinc powder, boil for 10min, remove residual zinc, cool and store in a plastic bottle. 4.5 Sulfuric acid absorption solution
4.5.1 Sulfuric acid storage solution: Measure 2.8mL sulfuric acid (4.1) in a 1000mL volumetric flask, dilute to scale with water, mix well, this solution is about 0.05mol/L
4.5.2 Sulfuric acid absorption solution: Transfer 100mL sulfuric acid storage solution (4.5.1) to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution is about 0.005mol/L.
4.6 Nessler's reagent: Weigh 14.5g sodium hydroxide (superior purity) and dissolve in 75mL water. Dissolve 5g mercuric iodide and 4g potassium iodide in 25ml water. Mix the two solutions, dilute to 100ml with water, mix well, let stand and take the clear solution and store it in a brown bottle. 4.7 Nitrogen standard solution
Approved by the State Administration of Technical Supervision on May 9, 1994, implemented on December 1, 1994
GB/T15076.13-94
4.7.1 Nitrogen standard stock solution: Weigh 0.3818g ammonium chloride (superior purity, baked at 110℃ for 1h), place it in a 100mL beaker, add water to dissolve, transfer to a 1000mL volumetric flask, dilute to the mark with water, and mix well. This solution contains 100μg nitrogen in 1mL. 4.7.2 Nitrogen standard solution: Transfer 100mL of nitrogen standard stock solution (4.7.1) to a 1000mL volumetric flask, dilute to the mark with water, and mix well. This solution contains 10μg nitrogen in 1mL.
4.8 Standard sample containing nitrogen.
5·Instruments and devices
5.1 Spectrophotometer
5.2 Steaming device
See Figure 1 for the distillation device.
Figure 1 Schematic diagram of the distillation device
1---Water vapor generating flask (2000~3000mL); 2 Waste liquid bottle (500mL); 3-Distillation flask (500ml); 4,5 Funnel; 6-Condenser; 7-Receiver (100mL) 6 Analysis steps
6.1 Determination quantity
Weigh two samples, measure them independently, and take the average value. 6.2 Test material
Weigh 0.5~1.0g of sample, accurate to 0.0001g. 6.3 Blank test
Carry out a blank test together with the sample. The blank value is not greater than 1pg. 6.4 Calibration test
Select a molybdenum standard sample with a nitrogen content close to that of the sample and measure it together with the sample. The absolute value of the difference between its value and the standard value shall not be greater than the standard allowable difference.
6.5 Measurement
6.5.1 Place the sample (6.2) in a volume of 30-50mL platinum blood, add 5-10mL of hydrofluoric acid-hydrochloric acid mixture, and after the violent reaction stops, heat it on an electric furnace until it is completely dissolved (if the sample is difficult to dissolve, add more mixed acid until it is completely dissolved), remove and cool. Add 10mL of warm boric acid solution and cool.
6.5.2 Place the receiver containing 10mL of sulfuric acid absorption solution (4.5.2) at the lower end of the condenser so that the liquid surface submerges the tube mouth. 532
GB/T 15076. 13-94
6.5.3 Transfer the test solution (6.5.1) into a pre-purged nitrogen-free distillation flask, and slowly inject about 35 mL of sodium hydroxide solution (4.4). Rinse with water to make the total volume of the distillate not exceed 150 mL. Heat and distill for about 15 minutes, so that the total volume of the absorption liquid and the distillate reaches 80 mL, and remove the receiver. 6.5.4 Transfer the distillate (6.5.3) into a 100 mL volumetric flask, dilute to the mark with water, and mix. 6.5.5 Transfer 10.0 mL of the test solution (6.5.4) into a 25 mL colorimetric tube, add 1 mL of Nessler's reagent, mix, and color for 15 minutes. 6.5.6 Transfer part of the test solution (6.5.5) into a 2cm absorber, and measure its absorbance at a wavelength of 420 mm on a spectrophotometer with water as a reference. 6.5.7 Subtract the blank absorbance of the sample and find the corresponding nitrogen content from the working curve. 6.6 Plotting the working curve
Pipette 0, 0.50, 1.00, 2.00, 3.00..10.00mL of nitrogen standard solution (4.7.2) into a 100mL volumetric flask, add 10mL of sulfuric acid absorbent (4.5.2) respectively, dilute to the mark with water, and mix. Proceed as in 6.5.5~6.5.6. Subtract the absorbance of the reagent blank, and plot the working curve with nitrogen content as the horizontal axis and absorbance as the vertical axis. 7 Calculation and expression of analysis results
Calculate the percentage of nitrogen by the following formula:
N(%)= m)xVeX10-6
Wherein: ml-the amount of nitrogen found from the working curve, ug; V. —total volume of test solution, mL;
V,-volume of test solution taken in one aliquot, mL; www.bzxz.net
mg~-mass of the sample, g.
The result should be expressed to 3 decimal places; if the nitrogen content is less than 0.01%, it should be expressed to 4 decimal places. 8 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Table 1
0. 002 0~ 0. 005 0
>0. 005 0~0. 010
>0. 010-~0. 020
Part II
Method 2 Distillation filling separation
9 Subject content and scope of application
This standard specifies the determination method of nitrogen content in filling. Filling
Titration method
This standard is applicable to the determination of fluorine content in filling. Determination range: >0.02%～0.2%. 10 Reference standards
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis methods GB1467 General principles and general provisions for chemical analysis methods for metallurgical products 11 Principles
The sample is dissolved in acid, nitrogen forms ammonium salt, the alkaline solution is distilled, the distillate is absorbed in boric acid solution, methyl red-methyl blue is used as an indicator, and the solution is titrated with hydrochloric acid standard solution.
12 Reagents
The water used in this standard is ammonia-free water.
12.1 Potassium sulfate, high-grade pure.
12.2 Sulfuric acid (pl.84g/mL), high-grade pure. GB/T 15076.13-94
12.3 Boric acid absorption solution (5g/L): Weigh 5g of boric acid (high-grade pure) and dissolve it in 1000mL of water and mix well. 12.4, Sodium hydroxide solution (500g/L): Weigh 500g sodium hydroxide (super pure) and dissolve it in 1000mL water, add 0.5g zinc powder, boil for 10min, remove the residual zinc, cool and store in a plastic bottle. 12.5 Hydrochloric acid standard titration solution [c(HCI)=0.01moL/L). 12.5.1 Preparation: Measure 8.4mL hydrochloric acid (p1.19g/mL, super pure) in a 1000mL volumetric flask, dilute to the scale with water, mix well, this solution is about 0.1moL/L. After calibration, accurately dilute 10 times for use. 12.5.2 Calibration
Weigh 3 portions of 0.2000g of sodium carbonate (reference reagent) pre-burned at 300℃ for 2h and cooled to room temperature in a desiccator is placed in a 250mL conical flask, dissolved in 25-30mL water, and 3 drops of methyl orange indicator (1g/L ethanol solution) are added. The solution is titrated with hydrochloric acid standard titration solution (12.5) until the solution changes from yellow to orange, which is the end point. The extreme value of the volume of hydrochloric acid standard titration solution consumed in parallel calibration should not exceed 0.1mL, and the average value is taken.
Carry out a blank test together with the calibration.
Calculate the actual concentration of the hydrochloric acid standard titration solution according to formula (1): m
(V,=V.)×0.0530
Where:
c--actual concentration of hydrochloric acid standard titration solution, mol/L; mj-
-mass of sodium carbonate, g; || tt||V,-The volume of the standard hydrochloric acid solution consumed in the titration of the sodium carbonate solution, mL; V. —The volume of the standard hydrochloric acid solution consumed in the titration of the blank solution in the calibration, mL; 0.0530-—The mass of sodium carbonate equivalent to 1.00 ml of the standard hydrochloric acid solution [c(HCI)=1.000 mol/L], g. 12.6 Nitrogen-containing saw standard sample.
12.7 Methyl red-
Mix evenly.
13 Instrument
Methyl blue mixed indicator: Weigh 0.125 g of methyl red and 0.083 g of methylene blue and dissolve them in 100 mL of ethanol. The distillation apparatus is shown in Figure 2.
14 Analysis steps
14.1 Determination of quantity
GB/T15076.13—94
Figure 2 Distillation apparatus Schematic diagram
1-Steam generating flask (2000-3000mL); 2-Waste liquid bottle (500mL); 3-Distillation flask (500mL): 45-Funnel, 6-Condenser; 7-Receiver (100mL)
Weigh two samples, measure them independently, and take the average value. 14.2 Test sample
Weigh 0.5g of sample, accurate to 0.0001g. 14.3 Blank test
Perform a blank test with the test sample
14.4 Calibration test
Select a standard sample with a nitrogen content close to that of the sample, and measure it with the test sample. The absolute value of the difference between its value and the standard value shall not be greater than the standard allowable deviation.
14.5 Determination
14.5.1 Place the test sample (14.2) in a conical flask and add 10mL sulfuric acid, about 2g potassium sulfate, slowly heat on an electric furnace until the sample is completely dissolved, remove and cool. Add 30mL of water to dissolve the salts, cool, and prepare for distillation. 14.5.2 Place a receiver containing 25mL of boric acid absorption liquid and 2 drops of methyl red-methylene blue mixed indicator at the lower end of the condenser so that the liquid surface submerges the tube mouth.
14.5.3 Transfer the test solution (14.5.1) into a pre-evaporated ammonia-free distillation flask, slowly inject 45mL of sodium hydroxide solution, rinse with water so that the total volume of the distillate does not exceed 150mL, heat and distill, about 15~~20min to make the total volume of the absorption liquid and distillate reach 150mL, remove the receiver, 14.5.4 Add 4 drops of methyl red-methylene blue mixed indicator to the distillate (14.5.3), mix well, and titrate with hydrochloric acid standard titration solution until the color changes from green to pink, which is the end point. 15 Calculation and expression of analysis results
Calculate the percentage of nitrogen according to formula (2):
N(%)=ex(V:-V)×0. 014)
Wherein; c-
actual concentration of hydrochloric acid standard titration solution, mol/L; X100
GB/T 15076.13-94
volume of hydrochloric acid standard titration solution consumed in titrating the sample solution, mL; V2——volume of hydrochloric acid standard titration solution consumed in titrating the blank solution in the determination, mL; 0. 014-
mass of nitrogen equivalent to 1.00mL hydrochloric acid standard titration solution [cHCl)=1.000mol/L], g. The result should be expressed to 2 decimal places; if the nitrogen content is less than 0.1%, it should be expressed to 3 decimal places. 16 Allowable Difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in the following table. Table 2
0.0200.050
>0.050~0.10
>0. 10~~0. 20
Additional Notes:
This standard is proposed by China Nonferrous Metals Industry Corporation. This standard is drafted by Ningxia Nonferrous Metals Smelter.
This standard is drafted by Ningxia Nonferrous Metals Smelter Method 1; Ningxia Nonferrous Metals Smelter and Jiujiang Nonferrous Metals Smelter drafted Method 2. The drafters of Method 1 of this standard are Wang Shulan and Tian Kongquan; the drafters of Method 2 are Wang Shulan and Liu Chuanxue. From the date of implementation of this standard, the former Ministry of Metallurgical Industry of the People's Republic of China issued the Ministry of Standards YB942 (8) -78 "Determination of Nitrogen Content in Molybdenum (Distillation-Nessler Reagent Absorption Spectrophotometry)" and YB942 (9) -78 "Determination of Nitrogen Content in Copper (Distillation-Volumetric Method)" shall be invalid.014-
Mass of nitrogen equivalent to 1.00mL of standard hydrochloric acid titration solution [cHCI) = 1.000mol/L], g. The result should be expressed to 2 decimal places; if the nitrogen content is less than 0.1%, it should be expressed to 3 decimal places. 16 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in the following table. Table 2
0.0200.050
>0.050~0.10
>0. 10~~0. 20
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Ningxia Nonferrous Metals Smelter. Supplement
This standard was drafted by Ningxia Nonferrous Metals Smelter Method 1; Ningxia Nonferrous Metals Smelter and Jiujiang Nonferrous Metals Smelter drafted Method 2. The drafters of Method 1 of this standard are Wang Shulan and Tian Kongquan; the drafters of Method 2 are Wang Shulan and Liu Chuanxue. From the date of implementation of this standard, the former Ministry of Metallurgical Industry of the People's Republic of China issued the Ministry of Standards YB942 (8)-78 "Determination of Nitrogen Content in Molybdenum (Distillation-Nessler Reagent Absorption Spectrophotometry)" and YB942 (9)-78 "Determination of Nitrogen Content in Copper (Distillation-Volumetric Method)" shall be invalid.014-
Mass of nitrogen equivalent to 1.00mL of standard hydrochloric acid titration solution [cHCI) = 1.000mol/L], g. The result should be expressed to 2 decimal places; if the nitrogen content is less than 0.1%, it should be expressed to 3 decimal places. 16 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in the following table. Table 2
0.0200.050
>0.050~0.10
>0. 10~~0. 20
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Ningxia Nonferrous Metals Smelter. Supplement
This standard was drafted by Ningxia Nonferrous Metals Smelter Method 1; Ningxia Nonferrous Metals Smelter and Jiujiang Nonferrous Metals Smelter drafted Method 2. The drafters of Method 1 of this standard are Wang Shulan and Tian Kongquan; the drafters of Method 2 are Wang Shulan and Liu Chuanxue. From the date of implementation of this standard, the former Ministry of Metallurgical Industry of the People's Republic of China issued the Ministry of Standards YB942 (8)-78 "Determination of Nitrogen Content in Molybdenum (Distillation-Nessler Reagent Absorption Spectrophotometry)" and YB942 (9)-78 "Determination of Nitrogen Content in Copper (Distillation-Volumetric Method)" shall be invalid.
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