GB/T 4324.3-1984 Chemical analysis methods for tungsten - Poly(ethylene glycol) octylphenyl ether-phenylfluorone spectrophotometric method for determination of tin content
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method of tungsten
Polyethylene glycol octyl phenyl ether - phenyifluorone photometric method for thedetermination of ttn contentUDC669.27:643
-42:546.811
GB 4324.3—84
This standard is applicable to the determination of tin content in tungsten powder, tungsten bar, tungsten trioxide, tungstic acid and ammonium paratungstate. The determination range is 0.00005~0.0040%. This standard complies with GB1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". ! Method summary
The sample is decomposed with peroxide and sodium hydroxide, and the main tungsten is complexed with sodium tartrate. In the presence of ammonium acetate buffer solution at pH 4.5-5.0, nickel is used as a co-extractant, sodium sulfate, and acetate-cyclohexane (1+1) to separate the tin from the organic phase and the main tungsten. Then, copper salt is used to replace the tin into the aqueous phase, and tartaric acid and citric acid are used to mask the remaining impurities. The tin content is determined by spectrophotometry using an emulsifier OP-tea fluorescent micelle solubilization in a 0.9N sulfur medium. 2 Reagents
2.1 Hydrogen peroxide (specific gravity 1.10), high-grade purity. Butyl acetate.
Cyclohexane.
Sulfuric acid (1+1), high-grade purity.
Sulfuric acid (5+95), high-grade purity.
Sodium hydroxide solution (40%), high purity. Sodium tartrate solution (20%).
Tartaric acid solution (20%).
Copper sulfate solution (4%).
Citric acid solution (50%).
Oxalic acid solution (6%).
Ammonium acetate buffer solution (10%), weigh 40g ammonium acetate, put it in a 500ml beaker, add 400ml water to dissolve, add 12ml sulfuric acid (2.4), mix well (pH4.5).
2.13 Washing liquid: weigh 15g oxalic acid and 25g ammonium acetate, dissolve in water and dilute to 1500ml, add about 15ml sodium hydroxide solution (2.6) until bromocresol purple turns yellow (pH15.1). 2.14 Nickel solution (0.5mg/ml): Weigh 1.68g of nickel ammonium sulfate [(NH4SO4.6H2O) in a beaker, dissolve with water, transfer to a 500ml volumetric flask, dilute to scale with water, and mix well. Sodium diethyldithiocarbamate (copper reagent) solution (5%). Prepare when needed, filter and use. 2.15
Bromocresol purple ethanol (1+4) solution (0.05%). 2.16
National Bureau of Standards 1984-04-12 issued
1985-03-01 implementation
GB4324.384
2.1 Polyethylene glycol octylphenyl ether (emulsifier OP) solution (5%). 2.1B Benzophenone ethanol solution (0.03 %): Weigh 0.1500g of phenylfluorone, place in a 150ml beaker, add 8ml of sulfuric acid (2.4), add several milliliters of anhydrous ethanol, heat and dissolve in a boiling water bath, cool, transfer to a 500ml brown volumetric flask with anhydrous ethanol, dilute to scale, and mix.
2.19 Tin standard solution
2.19.1 Weigh 0.1000g of metallic tin (more than 99.9%), place in a 100ml beaker, add 5ml of sulfuric acid (specific gravity 1.84), heat and dissolve in the electrolyte F. Continue to heat until white sulfuric acid smoke appears, remove and cool, add 5ml of tartaric acid solution (2.8), transfer to a 500ml volumetric flask with 2N sulfuric acid, dilute to scale, and mix. This solution contains 200μg of tin in 1ml. 219.2 Take 25.00 ml of the tin standard solution (2.19.1) and place it in a 1000 ml volumetric bottle, dilute it to the tin concentration with 2N sulfuric acid, and mix it. This solution contains 5 μg of tin in 1 ml.
3 Sample
The pigeon strips should be crushed and passed through a 120-month sieve.
Steps for separation
Quantity of determination
Double samples should be weighed for determination during analysis. The measured values should be within the allowable indoor difference and the industry average should be taken. 4.2 Sample!
Weigh the sample amount according to Table 1.
Tin, %
Sample amount, g
4. 3 Blank test
Carry out a blank test with the sample.
4.4 Determination
4.4.1 Tungsten powder, tungsten bar,
0.00005~0.001wwW.bzxz.Net
1.000~0.5000
>0.001~0.004
0.2000 ~0.1000
4.4.1.1 Place the sample (4.2) in a 100ml beaker, moisten it with a small amount of water, add 8~10ml hydrogen peroxide (2.1) twice, and after the violent reaction stops, place it on an electric furnace and heat it until the sample is completely dissolved, remove it and cool it, rinse the watch glass and the wall of the cup with water, and place it on a low-temperature electric heating plate to steam it.
4.4.1.2 Rinse a small amount of water along the wall of the cup, add 2.5ml sodium hydroxide solution (2.6), cover with blood, boil on the electric stove for 1~2min, remove and cool slightly, add 15ml sodium tartrate solution (2.7), add 2ml sulfuric acid (2.4) while shaking, place on the electric stove and boil for 1~2min, remove and cool.
4.4.1.3 Add water along the wall of the cup to about 30ml, add 0.2ml nickel solution (2.14), add 1 drop of bromocresol purple ethanol solution (2.16), adjust the sodium ammonia solution (2.6) to purple, and then adjust to yellow (pH5.1) with sulfuric acid (2.5), add 5ml ammonium acetate buffer solution (2.12) and 5ml copper reagent solution (2.15), and let it stand for 5min. 4.4.1:4 Use water to transfer into a 125ml graduated separatory funnel, control the volume of the paint liquid to about 50ml, add 8ml acetate (2.2) and 8ml cyclohexane (2.3), shake for 1min, and let stand to separate. 4.4.1.5 Discard the aqueous phase, add 30ml washing solution (2.13) and 1ml copper reagent solution (2.15) to the organic phase, shake for 1min, let stand to separate, discard the aqueous phase, and repeat washing the organic phase once. 4.4.1.6 Add 5ml water, 2ml tartaric acid solution (2.8), 1ml copper sulfate solution (2.9), and 1.25ml sulfuric acid (2.4) to the organic phase, mix each reagent, shake for 2.5min, and let stand to separate. 9
GB4324.3-84
4.4.1.7 Place the aqueous phase in a 25ml colorimetric tube containing 1.5ml citric acid solution (2.10), add 2ml emulsifier OP (2.17), 2ml distilled carbonyl ketone ethanol solution (2.18) and 2 drops of oxalic acid solution (2.11), and mix well after adding each reagent; dilute to the scale with water, mix, and let stand for 10 minutes.
4.4.1.8 Transfer part of the solution to a 3cm colorimetric tube, use the blank made with the sample as a reference, measure its absorbance at a wavelength of 508nm on a spectrophotometer, and find the corresponding tin amount from the plotted curve. 4.4.2 Tungsten monoxide, pigeon acid, ammonium secondary acid
Put the sample (4.2) in 100ml of flask, and draw the working curve according to 4.4.1.2~4.4.1.8 below
Pipette 0.00, 0.200, 40, 0.60, 0.80, 1.00ml of tin standard solution (2.19.2), and put them into a group of 25ml colorimetric tubes: 1.5ml of citric acid solution (2.10), 2ml of tartaric acid solution (2.8), 1.25ml of sulfuric acid (2.4), 2ml of emulsifier OP solution (2.17), 2ml of phenylfluorone ethanol solution (2.18), and mix each time a reagent is added. After adding 2 drops of oxalic acid solution (2.11), dilute to the scale with water, stir evenly, and let it stand for 10 minutes. 4.5.2 Transfer part of the solution into 3 cm3 colorimetric tube, take the reagent blank as reference, measure its absorbance at a wavelength of 508 mm with a photometer, take the tin content as the horizontal coordinate and the absorbance as the vertical coordinate, and draw a working curve. 5 Calculation of analysis results
Calculate the tin content according to the following formula:
Sn (%):
Formula, m,—the amount of tin found from the working curve, g; m
6 Allowable difference
Sample amount, g.
The difference in analysis results between experimental cases should not be greater than the allowable difference listed in Table 2. Table 2
0.00005 ~0.00020
0. D0020 ~ 0. (0040
.0.00840 ~ 0. 00080
>0.00080 - 0.0020
*n,0020~ 0.0040
Additional Note:
This standard was proposed by the Ministry of Metallurgy of the People's Republic of China. This standard was drafted by Zhuzhou Cemented Carbide Factory. This standard was drafted by Hunan Metallurgical Research Institute. ,人杨素那.
The original Ministry of Metallurgical Industry Standard YB895-77 "Tungsten Chemical Analysis Method" shall be invalidated from the date of implementation of this standard. 10
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