GB/T 4374.5-1984 Chemical analysis methods for magnesium powder and aluminum-magnesium alloy powder - Acetone-silver chloride turbidimetric method for determination of chlorine content

GB/T 4374.5-1984 Chemical analysis methods for magnesium powder and aluminum-magnesium alloy powders - Acetone-silver chloride turbidimetric method for determination of chlorine content GB/T4374.5-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of magnesium powders and aluminium -magnesium alloy powdersThe acetone silver chloride turbidimetric methodfor the determination of chlorine contentThis standard is applicable to the determination of chlorine content in magnesium powders and aluminium -magnesium alloy powders. Determination range1: 0.00200.030%. This standard complies with GB1467--78 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". Method Summary
UDC 669.721 -- 669
.715721492
：543.436
GB 4374.5---84
The sample is dissolved in sulfuric acid. In the presence of acetone, chlorine and silver nitrate form a silver fluoride emulsion, and its absorbance is measured at a wavelength of 420nm on a spectrophotometer.
25g mercury, 100μg fluorine and 10ug chromium are contained in the test solution respectively to prevent interference with the determination. 2 Reagents
2.1 Acetone.
2.2 Nitric acid (specific gravity 1.42).
2.3 Sulfuric acid (1+3).
2.4 Silver nitrate solution (1%).
2.5 Sodium hydroxide (super pure) solution (40%) 2.6 Chloride-free water*: Take 50ml deionized water, add 2 drops of nitric acid (2.2) and 1ml silver nitrate solution (2.1), and observe in a dark place. There should be no chloride ion reaction.
2.7 Magnesium matrix solution: Weigh 25.00g pure magnesium (99.99%), put it in an 800ml beaker, add 375ml sulfuric acid (1+2), and filter it into a 500ml container bottle after it is completely dissolved, cool to room temperature, dilute with water to the scale, and mix. This solution contains 50mg magnesium in 1ml. 2.8 Aluminum matrix solution: Weigh 12.50g pure aluminum (99.99%), place in an 800ml beaker, add 150ml sodium hydride solution (2.5), wait for it to dissolve, place the beaker in a cold water bath, slowly add 280m sulfuric acid (1+2) under constant stirring, heat until the solution is clear, filter into a 500ml volumetric flask, cool to room temperature, dilute with water to the mark, and mix well. This solution contains 25mg per 1ml. 2.9 Chlorine standard stock solution: Weigh 1.648g of sodium chloride (superior purity) pre-dried at 100-105℃, place in a 1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 1.0mg chlorine in 1ml. 2.10 Chlorine standard solution: Transfer 50.0ml of chlorine standard stock solution (2.9) to a 1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 50μg fluorine in 1ml.
Spectrophotometer.||t t||This standard refers to this type of water when it comes to reagent preparation and dilution water. Issued by the National Bureau of Standards on April 30, 1984
Implemented on April 1, 1985
Analysis steps
4.1 Determination quantity
Measure two samples and take the average value. 4.2 Sample quantity
Weigh the sample according to Table 1.
Chlorine. %
0.0020~0.0050
0.005 ~0.010
0.010 ~0.030
4.3 Blank test
GB4374.5—84
Sample quantity, g
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Weigh the sample (4.2) according to Table 1 and place it in a 300ml beaker. The following is carried out according to 4.4.2, 4.4.3 (without adding silver nitrate solution) and 4.4.4.
4.4 Determination
4.4.1 Place the sample (4.2) in a 300ml beaker. Add 30ml of water and slowly add 50ml of sulfuric acid (2.3). After the sample is completely dissolved, filter it into a 100ml volumetric flask and cool it to room temperature.
4.4.3 Add 3 ml nitric acid (2.2), 2 ml diketone (2.1), 2 ml silver nitrate solution (2.4), dilute to scale with water, and mix. Heat the solution (4.4.3) in a 70℃ water bath for 10 minutes, take it out, cool it to room temperature with running water, and place it in a dark place for 10 minutes. 4.4.4
4.4.5 Transfer part of the solution (4.4.4) to a 3 cm colorimetric tube, use the blank test solution (4.3) as a reference, measure its absorbance at a wavelength of 420nm with a spectrophotometer, and draw a curve from 1:1: to find the corresponding chlorine. 4.5 Drawing of working curve
4.5.1 Drawing of working curve of magnesium powder and chlorine
4.5.1.1 According to the sample volume (4.2), transfer an appropriate amount (the magnesium content should be equivalent to that of the sample (4.2)) of magnesium matrix solution (2.7) to a set of 100ml volumetric flasks, and add 0.00, 0.50, 1.00, 2.00, 2.50, 3.00ml of chlorine standard solution (2.10) respectively, and proceed as per 4.4.3 and 4.4.4.
4.5.1.2 Transfer part of the solution (4.5.1.1) to a 3cm colorimetric L4, and measure its absorbance at a wavelength of 420nm using the compensation solution (the solution without chlorine standard solution in 4.5.1.1) as the reference on a spectrophotometer. Draw a curve with the amount of chlorine as the horizontal axis and the absorbance as the vertical axis. 4.5.2 Drawing of the curve of chlorine in cobalt-magnesium powder 4.5.2.1 According to the sample volume (4.2), transfer appropriate amounts of the manganese and magnesium content (the amount of manganese and magnesium should be equivalent to that in the sample volume (1.2)) of the matrix solution (2.8) and the magnesium matrix solution (2.7), place them in a 100ml volumetric flask 4, add 0.00, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00ml of the fluorine standard solution (2.10) respectively, and proceed as in 4.4.3 and 4.4.4. 4.5.2.2 Transfer part of the solution (4.5.2.1) into a 3cm colorimetric tube 4, and measure its absorbance at a wavelength of 420nm on a spectrophotometer with the compensation solution (4.5.2.1 t/1 standard solution without chlorine added) as the reference. Draw a line 1. with chlorine content as the horizontal axis and absorbance as the vertical axis. 5
Calculation of analysis results
Calculate the chlorine content according to the following formula:
GB4374.584
ct (%)
Where: m is the chlorine content found on the line 1, g, and m is the sample weight, g.
Allowable difference
ml×100
The difference in analysis results between laboratories should not exceed the allowable difference listed in Table 2. Table 2
0.00200.0050
0.005-0.010bzxz.net
0.010~0.030
Additional Notes:
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard is drafted by Northeast Light Alloy and Northwest Aluminum. The main drafters of this standard are Guan Wenxiang and Wang Yejun. 158
Allowable Difference
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