GB/T 4374.4-1984 Chemical analysis methods for magnesium powder and aluminum-magnesium alloy powders - Determination of aluminum content by fluoride displacement complexometric titration

GB/T 4374.4-1984 Chemical analysis methods for magnesium powder and aluminum-magnesium alloy powders - Determination of aluminum content by fluoride displacement complexometric titration GB/T4374.4-1984 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 fluoride replacement-complexometry methodfor the determination of aluminium contentThis standard is applicable to the determination of aluminium content in aluminium magnesium alloy powders. Determination range: 45.00～55.00%. This standard complies with GB1467-78 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products" 1 Method Summary
UDC 669.721 +669
715721492
:543.244.6
GB 4374.4-84
The sample is dissolved in hydrochloric acid and aluminium and other metal ions are complexed with EDTA at pH 2.5~～2.8. At pH 5-6, titrate the excess EDTA with the standard solution, then use fluoride to complex aluminum and release a certain amount of EDTA, and use zinc standard solution to drop, thereby determining the amount of aluminum.
The test solution contains 1 mg of copper, iron, and manganese respectively, which will not interfere with the determination. 2 Reagents
2.1 Hydrochloric acid (1+4).
2.2 Sodium ethylenediaminetetraacetic acid (EDTA) solution (10%). 2.3 Hydrochloric acid potassium chloride solution (pH2.5): 2.3.1 Transfer 16.80 ml of hydrochloric acid (specific gravity 1.19), place it in a 1000 ml volumetric flask, dilute it to the scale with water, and mix it. 2.3.2 Weigh 14.90 g of potassium chloride, place it in a 500 ml beaker, add appropriate amount of water to dissolve it, transfer it to a 1000 ml volumetric flask, dilute it to the scale with water, and mix it.
2.3.3 Take 33.50ml hydrochloric acid (2.3.1) and 250.0ml potassium chloride solution (2.3.2), place in a 1000ml volumetric flask, dilute to the mark with water, and mix.
2.4 Acetic acid Sodium acetate solution (pH 5.5): Weigh 200g sodium acetate (CHCOONa-3H2O), place in a 500ml beaker, dissolve with appropriate amount of water, add 9ml glacial acetic acid, transfer to a 1000ml volumetric flask, dilute to the mark with water, and mix. 2.5 Saturated sodium fluoride solution.
2.6 Vanillin blue indicator solution (0.1%): weigh 0.1g vanillin blue, dissolve in 100ml (ethanol (1+A), mix well, 2.7
"cresol orange indicator solution (0.2%). 2.8 Zinc standard solution: weigh 5.000g pure zinc (99.99 or above), place in a 1200ml beaker, add 40ml hydrochloric acid (1-1) and heat until completely dissolved, cool, transfer to 1 000ml volumetric flask, dilute to scale with water, and mix well. This solution contains 5mg zinc in 1ml. 3
Analysis steps
3.1 Determination quantity
Parallel determination of two samples, take the average value. 3.2 Sample quantity
Weigh 0.1000g sample.
National Bureau of Standards 198404-30 Issued
19850401 Implementation
GB 4374.4—84wwW.bzxz.Net
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3.3 Determination
3.3.1 Place the sample (3.2) in a 500ml conical flask, add 15ml hydrochloric acid (2.1), heat to dissolve it completely, rinse the floating bottle peak with water, and cool.
3.3.2 Add 5 drops of vanillin blue indicator solution (2.6), neutralize with acetic acid sodium acetate solution (2.4) until the red sheet of the solution disappears and 5 drops are in excess. Add 10ml EDTA solution (2.2) 10ml hydrochloric acid-potassium chloride solution (2.3.3), boil for 2min, rinse the bottle wall and bottom with water, and cool.
3.3.3 Add 10l acetic acid-sodium acetate solution (2.4), 10 drops of diphenol orange indicator solution (2.7), and titrate with zinc standard solution (2.8) until the paint liquid turns red as the end point ( The volume of zinc standard solution is not taken into account). 3.3.4 Add 10 ml of saturated sodium fluoride solution (2.5), boil for 4 min, remove and cool. Add 5 drops of pink-orange titration solution (2.7), and titrate with zinc standard solution (2.8) until the solution turns red as the endpoint (the red color should be the same as the endpoint of the previous titration). Calculation of analysis results
Calculate the percentage of lead according to the following formula:
Where; C-concentration of zinc standard solution, g/ml, V---volume of zinc standard solution consumed, ml; mn---sample volume, g;
0.4127---conversion factor of zinc to lead. Allowable difference
CV×0.4127
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Aluminum
45.00 ~ 55.00
Additional Notes:
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Northeast Light Alloy Processing! Northeast Light Alloy Processing Plant and Northwest Aluminum Processing Plant. This standard was drafted by Xu Guochen and Zhengya Car.
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