This standard specifies the method summary, reagents, instruments, samples, analysis steps, calculation of analysis results and precision for the colorimetric determination of thorium dioxide in tungsten-thorium alloys. This standard applies to the determination of thorium dioxide in tungsten-thorium alloys. The determination range is thorium dioxide: 0.1~3.0% SJ/T 10379-1993 Determination method of thorium dioxide in tungsten-thorium alloys SJ/T10379-1993 Standard download decompression password: www.bzxz.net
This standard specifies the method summary, reagents, instruments, samples, analysis steps, calculation of analysis results and precision for the colorimetric determination of thorium dioxide in tungsten-thorium alloys. This standard applies to the determination of thorium dioxide in tungsten-thorium alloys. The determination range is thorium dioxide: 0.1~3.0%

Electronic Industry Standard of the People's Republic of China
SJ/T1037993
Determination of thiocyanate in tungsten needle alloys1993-07-21 Issued
1993-12-01 Implementation
The Ministry of Electronics Industry of the People's Republic of China Issued Electronic Industry Standard of the People's Republic of China
Determination of thiocyanate in tungsten alloys
Methocl for he determlnatlon of thoriundioxide in tharium tungsten alloys1 Subject content and scope of application
SJ/T 1037993
This standard specifies the method summary, reagents, instruments, samples, analysis steps, calculation and precision of the analysis results for the colorimetric determination of thiocyanate in tungsten needle alloys. This standard is applicable to the determination of thiocyanate in tungsten alloys, and the determination range is thiocyanate: C.1～3.0%. 2 Method Summary
The sample is dissolved in sulfuric acid and ammonium sulfate in a sulfuric acid medium of 0.5mnl/1. The needle forms a stable purple-red complex with the color developer sulfonic acid nitrogen phosphine, which is used for colorimetric determination. The interference of tungsten is masked by citric acid. 3 Reagents
3.1 Ammonium sulfate, solid.
3.2 Oxalic acid (5%).
3.3 Citric acid (40%).
3.4 ​​Sulfonic acid azo chlorophosphonate (0.03%). 3.5 Ammonia water (14mol/L),
3.6 Vegetable acid (2.5mol/L).
3.7 Sulfuric acid (18mol/L).
3.8 Ethanol (95%).
3.9 Carbonic acid solution (30%).
3.10 Buffer solution (about pH 3.3): Take 100mL acetic acid (98%) and 1CunmL sodium acetate solution (1m0l/L). Dilute with water to 100GmL and mix.
3.11 EDTA standard solution (0. 01mpl/L): Weigh 3.7224g of standard disodium ethylenediaminetetraacetate that has been pre-dried to constant weight at 105°C and cooled to room temperature in a desiccator, dissolve in 50-690mL water, dilute with water to 1000mL, mix, 3-12 Sodium dioxide standard solution (10ug/mL) 3.12.1 Preparation: Weigh 1.19g nitric acid [Th(NO)·4H2O] and dissolve in water, transfer to a 100mL volumetric flask, and dilute with water to the mark. This solution contains 1mg sodium. 3.12.2 Calibration: Take 25.00mL of sodium nitrate standard solution (3.12.1) and place it in a 250mL chain bottle. Add water to about 80mL, add one drop of p-nitrophenol, adjust to yellow with nitrogen water (1+1), and then adjust to colorless with hydrochloric acid (1-3), and add one drop of excess. Add 20mL of buffer solution (3.10) and appropriate amount of xylenol, and then calibrate with EDTA standard solution (3.21). The end point is when the purple-red color turns to yellow.
3.12.3 Calculation
Where:
Dioxide (mg/mL) = YX.0.01 X 264.038125.cO
-the amount of EDTA standard solution consumed, mL:
the concentration of EDTA standard solution.mol/,
264.0381——the amount of dioxide, 25.00
4 The number of milliliters of nitric acid standard solution absorbed by the artificial organ, mL. Photoelectric spectrophotometer:
5 Sample
.+-(1)
Put the tungsten needle alloy wire into a 200mL beaker, add about 50mL sodium carbonate solution (3.9), heat it to remove the surface graphite layer, make the surface bright, wipe it with qualitative filter paper, wash it with water, dehydrate it with ethanol (3.8), dry it, grind it into powder with a metal alloy mortar or cut it with scissors, and set it aside.
6 Analysis stepswww.bzxz.net
6.1 Sample quantity
Weigh 0.10-0.15g (accurate to 0.0001g) of the treated sample. 6. 2 Blank test
Perform a blank test with the sample.
6.3 Determination
6.3.1 Place the sample (6.1) in a 150mL dry beaker, add 3mL sulfuric acid (3.7), 3g ammonium thiolate (3.1), cover with table blood, heat on an electric furnace to dissolve, cool, add water to about 30mL, drop ammonia water (3.5) to neutralize, completely dissolve the precipitated tungsten, add 5mL citric acid (3.3), transfer to a 100mL volumetric flask, dilute to the scale with water, and mix well. 6.3.2 Accurately transfer 1.00mL of the above solution to a 25mL volumetric flask, add 5.0mL sulfuric acid (3.6), dilute to about 15mL with water, add two drops of oxalic acid (3.2), mix well, add 6.0mL of meta-sulfonic acid azophosphorus fluoride (3.4), dilute to the mark with water, mix well, use the reagent blank as the reference solution, use a 1cm cuvette, and measure its absorbance at a wavelength of 570nm on a photoelectric spectrophotometer.
6.3.3 Drawing of the working curve
Take 6 25mL volumetric flasks, add 0.50mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL of dihydrogenated standard (3.12), and perform the following analysis steps (6. 3.2), determine its absorbance. Use the total amount of sodium dioxide as the horizontal coordinate and the absorbance as the vertical coordinate to draw the working mountain line. 7 Calculation of analysis results
The percentage of sodium dioxide in tungsten needle alloy is calculated by the following formula:2
Where:x
8 Precision
SJ/T10379—93
Th,(%)
×100%
The amount of sodium dioxide found on the working line·: The amount of sample weighed, as much as possible.
8.1 Standard deviation (）
Where, i equals 1,2,3,4,5**
X, the first measurement value;
x—the average value of n measurements
1-the total number of measurements.
8. 2 Relative standard deviation (7 )
E(X - X)
×100%= 0. 42%
Where: 8—Standard deviation
—Average value of the measurements.
Additional remarks:
This standard is under the jurisdiction of the Electronic Standardization Institute of the Ministry of Electronics Industry. (2)
This standard was drafted by the Light Bulb Factory of Shanghai Vacuum Electronic Devices Co., Ltd. and the Standardization Institute of the Ministry of Electronics Industry. The main drafters of this standard are He Yi and Han Yanfen. 3
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