GB/T 4324.9-1984 Chemical analysis of tungsten - Determination of nickel content by dimethylglyoxime gravimetric method GB/T4324.9-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of tungsten
Determination of nickel content by dimethylglyoxime gravimetric method
Methods for chemical analysis of tungstenThe dt methylglyoxime gravimetric method forthe determination of nickel contentThis standard is applicable to the determination of nickel content in tungsten powder and tungsten bars. Determination range: 0.20～1.50%. This standard complies with GB1467--78 "General Principles and General Provisions of Standards for Chemical Analysis Methods of Metallurgical Products". 1 Method Summary
UDC 869.27 : 543
21 : 546.74
GB 4324.9—84
The sample is decomposed with sulfuric acid and ammonium sulfate, the main tungsten is complexed with citric acid, and nickel is precipitated with dimethylglyoxime at pH 8～9, and the content is determined by gravimetric method.
2. Reagents and materials
Ammonium sulfate.
Sulfuric acid (specific gravity 1.84).
Ammonium hydroxide (specific gravity 0.90).
Ammonium hydroxide (1+99).
Citric acid solution (50%), filter and set aside. 2.5
Para-nitrophenol ethanol solution (1%).
Butanedione ethanol solution (1%): weigh 1g butanedione in a beaker, add 100ml ethanol to dissolve, filter and dry into a brown 2.f
bottle.
pH test paper.
3: Instrument
Crocket filter [No. 3 or No. 4 (30ml)]. ． Sample
Tungsten bar should be crushed and passed through a 120-day sieve.
6 Analysis steps
5.1 Three samples should be weighed for measurement during analysis. The measured values ​​should be within the allowable difference in the room, and the average value should be taken. 5.2 Sample quantity
Weigh 1.000g of sample.
6. 3 Blank test
Carry out a blank test together with the sample.
5.4 Determination
5.4.1 Place the sample (4.2) in a 400ml beaker, add 7g of ammonium sulfate (2.1) and 10ml of sulfuric acid (2.2), place it in an electric furnace at high temperature. National Bureau of Standards 1984-04-12 Issued
1886-03-01 Implementation
GB4324.9—84
Heat to dissolve, remove and cool to room temperature, rinse the surface blood and the beaker wall with water, and dilute to about 200ml. 5.4.2 Add 10 ml of citric acid solution (2.5), stir evenly with a glass, add 2 drops of p-nitrophenol ethanol solution (2.6), adjust the solution to yellow with ammonium hydroxide (2.3), and then adjust the pH to 8-9. Check with pH test paper (2.8). While stirring continuously, add 15-20 ml of diacetyl ethanol solution (2.7), cover with table blood, boil, remove, place in a boiling water bath and heat for 15 minutes, cut off the power supply, keep warm for 90-120 minutes, take off, and cool to room temperature. 5.4.3 Use a pre-measured constant Filter through a crucible filter (3.1), wash the beaker and precipitate with cold ammonium hydroxide solution (2.4) for about 10 times, then place the crucible filter (3.1) at 115~125°C and bake for 60 minutes, take it out and place it in a desiccator for a period of time, cool it to room temperature (about 60 minutes>
Weigh and bake to constant weight. Calculate the percentage of nickel by subtracting the mass of the blank precipitate made with the sample from the mass of the precipitate.
Calculation of analysis results
Calculate the percentage of nickel by the following formula:
Ni (%) =-
Formula, m,
Allowance
Mass of nickel precipitate from diacetyl, g! bzxz.net
Sample amount, g!
Conversion factor for nickel diacetyl to nickel. m×0.2032
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the table below. Nickel
0.20~0.80
>,80 ~1.50
Additional explanation,
This standard was proposed by the Ministry of Metallurgy of the People's Republic of China. This standard was drafted by Zhuzhou Cemented Carbide. This standard was drafted by Zhuzhou Cemented Carbide Factory. The main drafters of this standard were Liu Tingdu and Tan Aiyun. ×100
Allowance
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB895-77 "Tungsten Chemical Analysis Method" will be invalid. 28
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