GB/T 15076.2-1994 Chemical analysis method of tantalum and niobium - Determination of niobium content in tantalum
Some standard content:
National Standard of the People's Republic of China
Chemical analysis methods of tantalum and niobium
·Determination of niobium content in tantalum
Methods for chemical analysis of tantalum and niobium-Determination of niobium content in tantalumGB/T 15076.294
Part I Method 1 Extraction, chromatography-DSPCF spectrophotometry 1 Subject content and scope of application
This standard specifies the method for the determination of niobium content in tantalum. This standard is applicable to the determination of niobium content in tantalum, and also to the determination of niobium content in its hydroxide and carbide. Determination range: 0.001%-~1.5%.
2 Reference standards
GB1.4 Standardization work guidelines Chemical analysis method standard preparation regulations GB1467 General principles and general provisions of metallurgical product chemical analysis method standards GB7729 General principles of metallurgical product chemical analysis spectrophotometry 3 Principle of the method
The sample is dissolved in hydrofluoric acid and nitric acid, and the saw is separated from molybdenum and other impurities by extraction and paper chromatography. It is melted with potassium pyrosulfate. Tartaric acid is leached. In the tartaric acid [C(C,HO.)-0.027mol/LJ medium, saw forms a green complex with N,N'-di(2-hydroxy-5-sulfophenyl)-C-hydroxymethylformamide, and its absorbance is measured at a wavelength of 660nm on a spectrophotometer. 4 Reagents and materials
4.1 Potassium pyrosulfate.
4.2 Hydrofluoric acid (pl.14g/mL).
4.3 Nitric acid (p1.42g/mL).
4.4 Butanone.
4.5 4-Methyl-pentanone-{2) (MIBK): In a 1000mL plastic separatory funnel, add 230mL water, 10mL hydrofluoric acid (4.2), and 10ml nitric acid (4.3) and mix. Add 350mL MIBK, shake for 2min, let stand and separate, discard the aqueous phase, and store the organic phase in a plastic bottle. Pretreatment. 4.6 Hydrofluoric acid (1+1).
4.7 Developing agent: butanone + hydrofluoric acid + nitric acid (90+2+8). 4.8 Tartaric acid solution (50g/L).
4.9 Potassium pyrosulfate solution (100g/L): Weigh 10g potassium pyrosulfate (4.1) and place it in a 30ml platinum crucible. Melt it on a blowtorch until it becomes transparent. Remove it, cool it, and place it in a 150ml beaker containing 80ml water. Heat it to extract it. Remove it and wash it out of the crucible with water, and cool it. Transfer the solution into a 100ml volumetric flask, dilute it to the mark with water, and mix it well. Approved by the State Administration of Technical Supervision on May 9, 1994 484
Implemented on December 1, 1994
GB/T15076.2-—94
4.10 N, N-bis(2-hydroxy-5-sulfophenyl)-C-cyanoformamide (DSPCF) solution: weigh 0.1g DSPCF in an 800ml beaker, add 500mL water to dissolve, transfer to a 1000mL volumetric flask, add 320mL hydrochloric acid (7+25), dilute to scale with water, and mix well. 4.11 Sodium nitrite solution (150g/L). 4.12 Saw standard stock solution: weigh 0.1431g of high-purity tantalum pentoxide that was previously burned at 1000C for 1h and cooled to room temperature in a desiccator, put it in a 30mL platinum crucible, add 2g of potassium pyrosulfate (4.1), heat until white sulfur trioxide smoke appears, melt it on a blowtorch until it is transparent, and cool it. ! Put it in a 400mL beaker containing 250mL tartaric acid solution (200g/L), heat it to dissolve the molten block, wash it out of the crucible with water, and cool it. Transfer the solution to a 500mL volumetric flask, dilute it to the mark with water, and mix it. This solution contains 200μg niobium in 1mL. 4.13 Saw standard solution: transfer 25.00mL of tantalum standard stock solution (4.12) to a 100mL volumetric flask, add 12.5ml of tartaric acid solution (200g/L), dilute it to the mark with water, and mix it. This solution contains 50ug saw in 1mL. 4.14 Standard stock solution: Weigh 0.1000g of metal niobium powder and place it in a 30mL platinum crucible, add 2ml of hydrofluoric acid (4.2), add nitric acid (4.3) dropwise, slowly heat to dissolve, cool, transfer to a 500mL volumetric flask, dilute to scale with water, and mix. Store in a plastic bottle. This solution contains 200μg of saw in 1mL.
4.15 Standard solution: Transfer 10.00mL of niobium standard stock solution (4.14) and place it in a 100mL volumetric flask, dilute to scale with water, and mix. Store in a plastic bottle. This solution contains 20μg of saw in 1mL. 4.16 Chromatographic paper: Medium-speed chromatography filter paper, 220mm×280mm, 2/3 of its length is soaked in ammonium nitrate solution (100g/L), dried for use. 4.17 Chromatographic strip: Cut the part of the chromatographic paper (4.16) soaked in ammonium nitrate into 2.5 cm wide chromatographic strips for later use. 5 Instruments and devices
5.1 Spectrophotometer.
5.2 Plastic extraction bottle: Weld a plastic capillary tube with a length of 100-150 mm on the mouth of a 60 mL plastic bottle. 5.3 Humidity control box: A circular, sealable container with a cover, 35 cm high and 40 cm in diameter, welded from polyethylene sheets. 5.4 Chromatographic tube: Take two 1000 mL wide-mouth plastic bottles, cut off the small diameter part of the bottle mouth, and use them as the cover and bottom respectively. 5.5 Neutralizer: A large-sized dryer with concentrated ammonia water (p0.90 g/mL) under the sieve plate. 5.6 Sprayer: Contain an acid solution (30 g/L). 6 Analysis steps
6.1 Quantity to be measuredwww.bzxz.net
Weigh two samples, measure them independently and take the average value. 6.2 Samples
Weigh the sample according to Table 1, accurate to 0.0001g. Table 1
锛内容
0. 001~~0. 004
>0. 004 ~~0. 015
0.015~0.035
>0. 035~0. 08
>0. 08~~0. 15
>0. 15~0. 35
>0. 35 ~-0. 80
>0. 80~1. 50
Test material quantity
Total test solution
Test solution
Melting coke
Potassium sulfate
(4. 1)μg
Add pyrolysis
Diffuse tartar
Add tartar
Acid solution
Acid solution
Potassium sulfate solution
(4. 9),mL
(4.8),nl./(4.8),mL
Absorption dish
Working curve
6.3 Blank test
Carry out a blank test with the sample.
6.4 Determination
GB/T 1 5076. 2-- 94
6.4.1 Place the sample (6.2) in a 30mL platinum crucible, add 1-3mL hydrofluoric acid (4.2), add nitric acid (4.3) dropwise, dissolve the sample completely, heat at low temperature, and evaporate to near dryness (just without mobile phase). 6.4.1.1 When the saw content is 0.001% to 0.08%, remove 6.4.1), drip 0.3 ml of hydrofluoric acid (4.2) along the wall to dissolve the salts, add 0.7 ml of nitric acid (4.3) and 9 ml of water. Pipette the test solution into a plastic extraction bottle (5.2). Then inhale 20 ml of MIBK (4.5), shake for 2 minutes, let it stand for stratification, put the water phase into the original crucible, and evaporate it to near dryness at low temperature. The following procedures are followed in 6.4.1.2. 6.4.1.2 When the saw content is 0.08% to 1.50%, add 0.5 to 1 ml of hydrofluoric acid (4.2), heat to dissolve the salts, remove and cool. Use a plastic pipette to absorb the test solution and apply it to the part of the color paper (4.16) that is not soaked with ammonium nitrate. The coating strip should be 3 cm away from the bottom edge of the color paper and the coating strip should be 2.5 to 3 cm wide. Dry at low temperature, wash twice with hydrofluoric acid (4.6), 0.5 mL each time, wash the crucible 3 times with butanone (4.4), 0.5 mL each time, apply the washing liquid on the original coated tape in turn, dry the coated tape while applying, and roll the chromatographic paper into a cylinder. 6.4.2 Place the chromatographic paper vertically in a humidity control box (5.3) with the coated tape at the bottom, and place a 500 mL beaker containing 400 mL boiling water in the box to wet the paper for 20 to 25 minutes. (In areas with humid climates, this item can be omitted). 6.4.3 Take out the paper and immediately place it in a chromatographic cylinder (5.4) containing a 1 cm liquid layer height of the developer (4.7). After sealing, develop at room temperature above 15°C for about 3 hours. When the front edge of the developer rises to about 2 cm from the top of the paper, take it out. Dry. Place it in a neutralizer (5.5) and neutralize until no white smoke comes out of the paper.
6.4.4 Use a sprayer (5.6) Spray the acid solution to make the niobium strip color, and dry it. Cut the orange-yellow saw strip and place it in platinum. At the same position, cut a blank according to the width of the saw strip. After ashing on a high-temperature electric furnace, place it in a 600℃ high-temperature furnace and burn it until it turns white. Take it out and cool it. 6.4.5 Add potassium pyrosulfate (4.1) according to Table 1, remove the water on the electric furnace, melt it on a blowtorch until it is transparent, and cool it. Add tartaric acid solution (4.8) according to Table 1, blow the crucible wall with water, heat at low temperature until the molten block is dissolved, take it out and cool it. 6.4.5.7 Transfer the test solution (6.4.5) that needs to be colored in full into a 25mL colorimetric tube according to Table 1, dilute it to 10ml with water, and mix it. 6.4.5.2 Transfer the test solution (6.4.5) that needs to be colored in a fraction into the corresponding volumetric flask according to Table 1, dilute it to the scale with water, and mix it. According to Table 1, take the test solution and place it in a 25mL colorimetric tube, add potassium pyrosulfate solution (4.9) and tartaric acid solution (4.8), dilute to 10mL with water, and mix. 6.4.6 Add 10mL DSPCF solution (4.10) and mix. Place the colorimetric tube in a boiling water bath and heat for 8 minutes, take it out, add 6 drops of sodium nitrite solution (4.11), cool, dilute to 25mL with water, mix, open the stopper of the colorimetric tube, and let the bubbles escape. 6.4.7 According to Table 1, transfer part of the solution into the corresponding absorption blood, use water as reference, and measure its absorbance at a wavelength of 660nm on a spectrophotometer.
6.4.8 Subtract the absorbance of the blank solution accompanying the sample and find the amount from the corresponding working curve. 6.5 Drawing of working curve
6.5.1 Working curve 1
6.5.1.1 Take 0, 0.25, 0.50, 0.75, 1.00, 1.25mL of saw standard solution (4.15) and apply them on a set of color paper tapes (4.17) respectively. Dry while applying. Place the paper tapes in a 30mL platinum crucible. After ashing on an electric furnace, burn them in a high-temperature furnace at 600℃ until they turn white. Take them out and cool. Weigh 0.4g of potassium pyrosulfate (4.1) and place them in a crucible. Heat to remove moisture. Melt them on a blowtorch until they are transparent. Cool. Add 2mL of tartaric acid solution (4.8) to the crucible and wash the crucible wall with water. Take it out and cool. Transfer the test solution into a 25mL colorimetric tube, dilute it to 10mL with water, and mix well. The following operations are carried out according to 6.4.6~~6.4.7.
6.5.1.2 Subtract the absorbance of the reagent blank, and draw a working curve with the saw amount as the horizontal axis and the absorbance as the vertical axis. 6.5.2 Working curve 1
Pipette 0, 0.200.40, 0.80, 1.20, 1.60, 2.00mL of saw standard solution (4.13). Place them in a set of 25mL colorimetric tubes, add tartaric acid solution (4.8) to 2mL, add 4mL potassium pyrosulfate solution (4.9), add water to 10mL, and mix. The following operations are carried out according to 6.4.6~6.4.7 and 6.5.1.2.
Calculation and expression of analysis results
Calculate the percentage of saw as follows:
GB/T 15076.2--94
Nb(%)=ml:VaX10-6
Wherein: ml--the amount of saw obtained from the working curve, μg; V. ---~total volume of test solution.mL
Vi-volume of test solution taken, mL;
mass of test material, g.
8 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
0.0010~0.0025
>0. 0025~0. 0060
>0. 0060~0. 0150
≥>0. 015 ~ 0. 035
>0. 035~0. 080
>0. 080~0. 150
>0.150~0.350
>0. 35~0.80
>0. 8~1. 5
Part II Method 2
9 Subject content and scope of application
This standard specifies the method for the determination of the content of cobalt in molybdenum. X100
Chromatographic separation gravimetric method
This standard is applicable to the determination of the content of tantalum, the determination range: >1.5%～6%. 10 Reference standards
GB1.4 Standardization work guidelines for the compilation of chemical analysis methods GB1467 General principles and general provisions for chemical analysis methods for metallurgical products 11 Principle of the method
Allowance
The sample is dissolved in hydrofluoric acid and nitric acid. The saw is separated from molybdenum and other impurities by paper chromatography, and the saw weight is weighed after burning. 12 Reagents and materials
12.1 Nitric acid (p1.42g/ml).
12.2 Butanone.
12.3 Hydrofluoric acid (1+1).
GB/T 15076.2--94
12.4 Developing agent: 4-methyl-pentanone-{2+butanone+hydrofluoric acid+nitric acid (44+44+8+4). 12.5 Acid solution (50g/L).
12.6 Chromatographic paper: Medium-speed chromatography filter paper 220mm×280mm, soak the chromatographic paper with ammonium nitrate solution (100g/L) along the length (28cm) to 2/3, dry and set aside.
13 Instruments and equipment
13.1 Analytical balance: sensitivity 0.01mg.
13.2 Chromatographic box: A sealed container with a lid made of polyethylene or polyvinyl chloride. 13.3 Neutralizer: It can be replaced by a medium-sized dryer, and the lower part of the sieve plate is filled with ammonia water (p0.90g/mL). 13.4 Sprayer: filled with acid solution (12.5). 14 Analysis steps
14.1 Determination quantity
Weigh two samples, measure independently, and take the average value. 14.2 Sample
Weigh 0.1g of sample, accurate to 0.00001g. 14.3 Blank test
Perform a blank test with the sample.
14.4 Determination
14.4.1 Place the sample (14.2) in a 30mL platinum crucible, add 2mL of hydrofluoric acid (12.3), add about 0.3mL of nitric acid (12.1), and heat slowly until the sample is completely dissolved. Continue heating to evaporate the test solution to 0.5~0.8mL. 14.4.2 Use a plastic pipette to absorb the test solution (14.4.1) and apply it to the part of the chromatographic paper (12.6) that has not been soaked with the ammonium nitrate solution. The coating strip should be 3 cm away from the bottom of the paper and 2 to 3 cm wide. Dry at low temperature. Wash the crucible twice with hydrofluoric acid (12.3), about 0.4 ml each time, and wash the crucible three times with butanone (12.2), about 0.5 ml each time. Apply the washing solution to the original coating strip in turn, drying the coating strip while applying. Roll the chromatographic paper into a cylinder. 14.4.3 If the part of the chromatographic paper soaked with the ammonium nitrate solution is dried too dry, place the paper sheet (14.4.2) in a steam bath or relatively humid air to rehydrate it. Place the paper sheet vertically with the coating strip at the bottom into the chromatographic box (13.2) containing a developer (12.4) about 1 cm high, seal it, and develop it at room temperature above 15°C for about 3 hours. 14.4.4 When the front edge of the developing agent rises to 2 cm from the top of the paper, take it out and dry it. Put it on the screen plate of the neutralizer (13.3) and neutralize it until no white smoke comes out of the paper. Use a sprayer (13.4) to spray the acid solution (12.5) to make the molybdenum and saw develop color, and dry it. Cut the orange-yellow niobium strip. Place the cut color layer paper in 15 mL of platinum that has been constant weight, heat it to ashing, and burn it in a high-temperature furnace at 900℃ for 1 hour. Take it out, 14.4.5
Place it in a desiccator and cool it. Weigh it on the analytical balance (13.1) and burn it repeatedly until constant weight. 14.4.6 Cut the blank white layer paper accompanying the sample at the same position according to the width of the roller strip, and operate according to 14.4.5 below. 15 Calculation and expression of analysis results
Calculate the percentage of saw pentoxide according to the following formula:
Nb(%)=(m1=m)=(m==m)×0.6990×100mo
total mass of crucible and burning material, g;
wherein: m—
mass of burning material, g;
m3——total mass of crucible and blank, g;
m4-mass of crucible containing blank, g;
.mo-mass of test material, g;
16 Allowable difference
GB/T15076.2—94
The coefficient for converting saw pentoxide into saw pentoxide,
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Table 3
Kun content
1. 50～2. 00
>2.00~4.00
>4.00~~6.00
Additional Notes:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Ningxia Nonferrous Metals Smelting. Method 1 of this standard was drafted by Ningxia Nonferrous Metals Smelting Plant. The main drafter of Method 1 of this standard was Zhang Lanfen. Method 2 of this standard was drafted by Zhuzhou Cemented Carbide Plant. The main drafters of Method 2 of this standard were Huang Xiangyuan and Pan Zhengfei.
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