GB 4374.8-1984 Chemical analysis methods for magnesium powder and aluminum-magnesium alloy powders. Determination of active magnesium and active aluminum-magnesium content by gas volumetric method. Download and decompress password for GB4374.8-1984 standard: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of magnesium powders and aluminium-magnesium alloy powdersThe gasometric method for
the determination of active magnesiumand active aluminium-magnesium contents669.721+669
.715721492
GB 4374.8-84
This standard is applicable to the determination of active magnesium in magnesium powder and active aluminium-magnesium in magnesium alloy powder. Determination range: 94% or less. This standard complies with GB1467-178 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". Method Summary
The sample reacts with hydrochloric acid, and the active magnesium or active aluminium-magnesium displaces an equivalent amount of chlorine. The active magnesium or active magnesium content is calculated based on the hydrogen volume.
2 Reagents
2.1 Hydrochloric acid (1+4)
2.2 Sealing solution: 25% sodium chloride solution, with 0.1% methyl orange solution as indicator, use hydrochloric acid (2.1) to adjust the whole solution to red color and saturate with oxygen.
3.1 Gas measuring instrument (see the figure below) α
3.2 Level bottle (fill with appropriate amount of sealing solution). 3.3 Mercury.
National Bureau of Standards 198404·30 Issued
19850401 Implementation
Analysis steps
4.1 Determination quantity
GB 4374.8-84
Q-sample tube: b-reaction bottle; c-water tank: d→gas tube, e-most gas tube piston: f-thermometer, g-air vent, h-level bottle Parallel determination of two samples, take the average value. 4.2 Sample quantity
Weigh 0.0700~0.0900g magnesium powder or aluminum-magnesium alloy powder. 4.3 Determination
iiKAoNikAca=
4.3.1 Place the sample (4.2) in the weighing tube, transfer it to the reaction bottle pre-filled with 20ml hydrochloric acid (2.1), and tighten the rubber stopper. 4.3.2 Turn the piston of the gas pipe to make the gas pipe communicate with the exhaust hole of the piston. Lift the level bottle to exhaust as much air as possible in the gas pipe, turn the piston of the gas pipe to make the gas pipe communicate with the reaction bottle, and put down the level bottle. 4.3.3 Adjust the temperature of the cooling water in the water tank to the same as the temperature of the water in the gas pipe interlayer, and let it stand for 10 minutes. Lift the level bottle to make the liquid level of the closed solution in the level bottle exceed the liquid level of the closed liquid in the gas pipe. Slowly lower the height of the level bottle until the liquid level in the gas pipe is level with the liquid level in the level bottle. As above, record the scale value every 7 minutes or so. If it remains unchanged twice, it is the starting point. Record the air pressure, temperature and starting point reading at this time.
GB 4374.8 ---84
4.3.4 Gently shake the reaction bottle to make the sample react with hydrochloric acid. Place the reaction bottle in the water tank and shake it about every 10 minutes. After the reaction is completed, let it stand for 10 minutes. At this time, the sealing solution has dropped to the lower scale of the burette. Every 7 minutes or so, lift the secondary level bottle so that the liquid level in the level bottle exceeds the liquid level in the burette and slowly lower the level bottle until the liquid level in the burette is level with the liquid level in the level bottle and the two readings remain unchanged. Record the display, temperature and volume readings at this time. The room temperature should be kept effective during operation. 5
Calculation of analysis results
According to formula (1) and formula (2), the active magnesium content of magnesium powder or aluminum-magnesium alloy powder is calculated as follows: Active magnesium (%)
(P, - P2 P:) V×0.0003898
(273 +t) mm
Active magnesium (%)=_(P--P3)V.
(273 +t) mg
Formula: P
-it reading, mmHg;
× 100 .....
Steam gauge reading temperature correction value, mmHg; check the commonly used table No. "Air pressure reading temperature correction table".
Ps----saturated water vapor pressure at tC, mmHg;V——volume of quasi-oxygen, ml;
t——temperature of the measuring tube during measurement, ℃;; 0.0003898
Conversion factor for oxygen to active magnesium;
K-hydrogen to active Conversion factor for active aluminum and magnesium. See Appendix A (Supplement); mo--sample size, g.
Allowable error
The difference in analysis results between laboratories should not be greater than the allowable error listed in the following table. Active magnesium and active aluminum magnesium rat
Allowable error
(2)
0.0003365
-0003361
0.0003363
0.000336 2
0.0003361
0.0003360
0.0003359
n.0003358
0.0003357
0.0003356
0.0003355
h.0003354
6.0063353
0,0003352| |tt||0.0003351
0.0003350
,00033.19
0.0003348
0.0003347|| tt||0.0003346
0.0003345
.0003341
0.0003342
0.0003341||tt ||n.0003340
0.um03339
n.0003338
Q.0003337
0.0003336
0.0003335
3.0003334
n.o003333
GB4374.8—84
Appendix A
Hydrogen is converted to Conversion factor table of active aluminum and magnesium (supplement)
0.0003331
.0333328
0.0003327
.003326
0.1003323
0.0003322
n.0003321
.0003319
1.0003318
0.0003317
0.1003316
0.0303313
0.0003314
t.0003313
0 .0003312
0.0003311
0.0003310
0.0003309
0.0003308
0. 0003306
0.0003305
0.0003304
0.0003393
0.0003302
0.0 003301
0.0003300
0.0003299
0.0003298
iiKAoNiKAca=
1, 6000 297
n,0003296Www.bzxZ.net
0.001329)
0.0003291
0. 003292
-00329
0.0503290
0.0003289
u.0003288
0.10 003287
0.0013286
0.000328.
n.0163283
.06103282
0. 00303281
th.on0328m
.0063279
.0003278
11-4100327 7
0.0003276
0.0003273
0.0003274
.0003271
0.0303269
0,0003268
1.0003267
n.0003266
H.0003265
Additional Notes:
GB 4374.8—84
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 Co., Ltd. This standard is drafted by Northeast Light Alloy Co., Ltd. and Northwest Aluminum Co., Ltd. The main drafters of this standard are Xu Fachen and Tuo Yejun.
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