GB/T 21524-2008 PDF in English
GB/T 21524-2008 (GB/T21524-2008, GBT 21524-2008, GBT21524-2008)
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GB/T 21524-2008 | English | 115 |
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Particle size determination of inorganic chemical products -- Sieving method
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GB/T 21524-2008: PDF in English (GBT 21524-2008) GB/T 21524-2008
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.10
G 10
Particle size determination of inorganic chemical products -
Sieving method
(ISO 2926:1974, NEQ)
ISSUED ON: APRIL 01, 2008
IMPLEMENTED ON: SEPTEMBER 01, 2008
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Principle of the method ... 5
5 Apparatus ... 5
6 Analysis procedure ... 6
7 Result calculation ... 7
Particle size determination of inorganic chemical products -
Sieving method
1 Scope
This Standard specifies the methods for the determination of particle size in inorganic
chemical products.
This Standard is applicable to the determination of particle size in inorganic chemical
products with a particle size larger than 45 μm and are non-hygroscopic or insoluble in
water.
2 Normative references
The following documents contain the provisions which, through reference in this
Standard, become the provisions of this Standard. For dated references, their
subsequent amendments (excluding corrigendum) or revisions do not apply to this
Standard. However, the parties who enter into agreement based on this Standard are
encouraged to investigate whether the latest versions of these documents are applicable.
For undated reference documents, the latest versions apply to this Standard.
GB/T 6003.1-1997 Test sieves of metal wire cloth (eqv ISO 3310.1:1990)
3 Terms and definitions
For the purpose of this Standard, the following terms and definitions apply.
3.1
hand sieving method
A sieving method in which the test sieve is vibrated back and forth by hand, the test
sieve is gently collided with the other hand at the amplitude distance, and the resulting
vibration causes the particles smaller than the hole size to pass through the sieve holes.
3.2
mechanical sieving method
A sieving method in which the test sieve is installed on a vibrating sieving machine,
and the test sieve is vibrated by the vibrating machine.
6 Analysis procedure
6.1 Assemble the test sieves of the specified size in order to increase sieve holes from
the bottom to the top.
6.2 Weigh 20.0 g ~ 50.0 g of sample with a balance, to the nearest 0.02 g. Put it on the
test sieve at the top and close the top cover.
6.3 Determination
6.3.1 Hand sieving method
Carry out the test through vibration by hand. The amplitude is about 0.1 m, the
frequency is about 120 times/min, and the sieving duration is 3 min ~ 5 min. Let it stand
for 3 min, and weigh the sieve residue of each sieve or under each sieve. The
determination method is according to 6.4.
6.3.2 Mechanical sieving method
Install the test sieve containing the sample on the vibrating sieving machine, of which
the amplitude is 2 mm, the frequency is 120 times/min, and the vibration duration is 5
min. Let it stand for 3 min, and weigh the sieve residue.
6.3.3 Brush sieving method
Put the sample on the test sieve, and brush repeatedly with a wool brush until there is
no trace of the sample on the black backing paper. Let it stand for 3 min, and weigh the
sieve residue. The determination method is according to 6.4.
6.3.4 Wet sieving method
Put the sample on the test sieve, repeatedly rinse with water or immerse it in water, and
brush repeatedly with a wool brush until the sample does not flow out in the rinse water.
Let it stand for 3 min, place the test sieve in an electric oven at (105 ± 2) °C to dry until
the mass is constant, and weigh the sieve residue to the nearest 0.0002 g.
6.4 The sieving process shall be continued until the mass fraction of the sample passing
through the test sieve with the largest remaining particle size class within 1 min is less
than 0.1 %. Carefully brush the sample left on each sieve and the bottom plate with a
brush, and weigh the sieve residues (m1) of the test sieves of each particle size class,
respectively. The difference between the sum of the amount of all sieve residues and
the weighed sample amount shall not be greater than 1.5 %, otherwise, re-sample for
determination.
6.5 After each determination, use ultrasonic to clean the whole set of sieves to ensure
that the clogging of the test sieves is not greater than 1.0 %.
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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