GB/T 4324.30-1984 Chemical analysis of tungsten - Gravimetric method for determination of loss on ignition GB/T4324.30-1984 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China:
Chemical analysis method of tungsten
Gravimetric method for the determinationof loss' content on ignition
Methods for chemical snalysis of tungstenThe gravimetric method for the determinationof loss' content on ignitionThis standard is applicable to the determination of loss' content on ignition in tungsten trioxide. Determination range: 0.05～1.00%. Not in compliance with GB1467~-78 "General Principles and Some Provisions of Chemical Analysis Methods for Metallurgical Products" Method Summary
UDC 669.27:543
GB 4324.30-84
=Tungsten oxide is burned at 780～800℃, and the water, ammonium salt and volatile matter escape, and the lost mass is the loss on ignition. 2 Analysis steps
2.1 Determination quantity
Three samples should be weighed for determination during analysis. The measured values ​​should be within the allowable difference in the room, and the average value should be taken. 2.2 Sample quantity
Weigh 2.000g sample.
2.3 Determination
2.3.1·Place the porcelain crucible in a high-temperature furnace at 780-800℃ and burn for 1h. Take it out and cool it slightly. Place it in a lower desiccator and cool it to room temperature. Weigh it. Then place the crucible in a high-temperature furnace at 78~800℃ and burn for 30min. Take it out and cool it slightly. Place it in a lower desiccator and cool it to room temperature (the cooling time should be the same as the previous time). Weigh it. Repeat this operation until the constant weight is reached. 2.3.2 Place the sample (2.2) in a porcelain crucible that has been weighed, place it in a high-temperature furnace at 780-800℃ (the temperature should not exceed 800℃) and burn it for 2h. Take it out and cool it slightly. Place it in a desiccator and cool it to room temperature (the cooling time should be the same as the cooling time of the empty crucible). Weigh it. Then place the porcelain in a high-temperature furnace at 780-800℃ and burn it for 30min. Take it out and cool it slightly. Place it in a desiccator and cool it to room temperature (the cooling time should be the same as the previous time). Weigh it. Repeat this operation until the temperature is constant. 3 Calculation of analysis results
Calculate the ignition loss according to the following formula, ignition loss (%)
where: m, -
, allowable difference
- the mass of the porcelain crucible that has been weighed before the sample is burned, length! The mass of the sample and the porcelain crucible after burning,
- the mass of the sample, g.
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in the following table. Issued by the National Bureau of Standards on April 12, 1984
Implemented on March 1, 1985
Additional Notes:
Double-burned tip
0.10~0.40
≥0.40~0.70bZxz.net
>0.,70~1.00
GB4324.30—84
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Zhuzhou Cemented Carbide Factory. This standard was drafted by Zhuzhou Cemented Carbide Factory. The main drafter of this standard is Wang Jidian
Allowable Difference
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB895-77 "Chemical Analysis Method of Tungsten" will be invalidated. 104
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