GB/T 5448-2014 English PDF (GBT5448-2014)

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GB/T 5448-2014: Determination of the crucible swelling number of bituminous coal -- Electrical heating method
GB/T 5448-2014
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 73.040
D 21
Replacing GB/T 5448-1997
Determination of the crucible swelling number of
bituminous coal - Electrical heating method
(ISO 501:2003, Hard coal - Determination of the crucible swelling number, MOD)
ISSUED ON: JUNE 09, 2014
IMPLEMENTED ON: OCTOBER 01, 2014
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
National Standardization Administration.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Method summary ... 5
4 Instruments and equipment ... 5
5 Specimen preparation ... 8
6 Instrument debugging ... 9
7 Test steps ... 9
8 Result expression and reporting ... 10
9 Method precision ... 10
10 Test report ... 11
Appendix A (Informative) Structural changes of this standard compared with ISO
501:2003 ... 12
Appendix B (Informative) Technical differences between this standard and ISO
501:2003 and their reasons ... 13
Determination of the crucible swelling number of
bituminous coal - Electrical heating method
1 Scope
This standard specifies the method summary, instruments and equipment, test
preparation, test steps, result expression, method precision, test report, for determining
the crucible swelling number (CSN).
This standard applies to bituminous coal.
2 Normative references
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document;
for the undated documents, only the latest version (including all the amendments) is
applicable to this standard.
GB 474 Method for preparation of coal sample
GB/T 483 General rules for analytical and testing methods of coal
3 Method summary
Place the coal sample in a special crucible, to heat it to (820 ± 5) °C according to the
specified procedure. The obtained coke block is compared with the side shape diagram
of a set of standard coke blocks with serial numbers. Use the closest coke shape number
as the crucible swelling number.
4 Instruments and equipment
4.1 Electric heating furnace (Figure 1)
On a grooved refractory plate, which has a diameter of 100 mm and a thickness of 13
mm, wind a nickel-chromium wire coil, which has a power of 1000 W. The refractory
plate is placed on a board with the same specifications. Cover a quartz dish, which has
a wall thickness of 1 mm, a height of 10 mm, an outer diameter of 85 mm, to
accommodate the crucible.
The above-mentioned heating part is placed in a refractory brick, which has a diameter
of 140 mm and a groove with a depth of 60 mm and a diameter of 105 mm. The top is
covered by a 20 mm thick refractory plate. There is a 50 mm diameter hole in the center
of the plate, to accommodate the crucible. The entire refractory brick is placed on a 3
mm ~ 5 mm thick asbestos board. Fill insulation material between the surrounding
bricks and the furnace shell. There is a refractory cover on the top of the furnace and a
hole in the bottom. Insert the temperature-measuring thermocouple through the hole,
until its hot junction is in contact with the inner surface of the quartz vessel. The electric
heating furnace is equipped with suitable temperature measurement and temperature
control devices.
4.2 Crucible and cover (Fig. 2)
It is made of porcelain or quartz, that is resistant to high temperatures (greater than
1000 °C). Crucible total height: (26 ± 0.5) mm; top outer diameter: (41 ± 0.75) mm;
bottom inner diameter: 11 mm ~ 14 mm; mass: 11 g ~ 12.75 g; volume: 16 mL ~ 17.5
mL; inner diameter of crucible cover (no hole) 44 mm, height 5 mm.
4.3 Crucible cover with hole (Figure 3)
It is made of high temperature resistant ( >1000 °C) porcelain or quartz. The size is the
same as the 4.2 Crucible cover without hole; it has a 6 mm diameter round hole, for
insertion of thermocouple.
4.4 Thermocouple
Armored nickel-chromium galvanic couple, 2 pieces.
4.5 Coke block observation tube (Figure 4)
The coke block observation tube shall comply with the requirements in Figure 4.
4.6 Heavy objects
(500 ± 10) g flat bottom weight.
4.7 Timer
Accurate to seconds (s).
4.8 Balance
The minimum graduation value is 0.01 g.
to GB 474. During specimen preparation, coal specimens shall be prevented from being
ground too finely. The specimen shall be tested as soon as possible after preparation;
otherwise, it shall be sealed and refrigerated. The test period shall not exceed 3 days.
The coal specimens shall be thoroughly mixed for at least 1 minute before weighing.
6 Instrument debugging
Turn on the electric heating furnace. Heat it to about 850 °C and maintain a constant
temperature. Open the furnace cover. Place a cold empty crucible into the center of the
quartz dish in the furnace (start the stopwatch at the same time). Quickly apply the
crucible cover with a hole. Then insert the thermocouple into the crucible through the
cover hole. Press it to make the hot contact be close to the inner surface of the bottom
of the crucible. Observe the temperature rise, without covering the electric furnace
cover. If the bottom temperature in the crucible reaches (800 ± 10) °C within 1.5
minutes and reaches (820 ± 5) °C within 2.5 minutes after the cold crucible is put in,
record the furnace temperature and current and voltage adjustment method. Follow this
method when conducting the test control. If the above requirements cannot be met,
adjust the voltage, current, furnace temperature, until the above requirements are met.
7 Test steps
7.1 Weigh (1.00 ± 0.01) g of air-dried coal specimen. Put it into the crucible and shake
it flat. Then place it on a rubber board, which has a thickness of not less than 5 mm.
Grasp the crucible containing the coal specimen downwards with the five fingers of
your hand, to lift it about 15 mm height. Let go and let it fall freely. Fall like this for a
total of 12 times (rotate the crucible by an angle each time it falls).
7.2 Open the furnace cover. Place the crucible containing the coal specimen into the
center of the quartz dish in the furnace, that has been heated to the predetermined
temperature. Immediately cover it with a crucible cover without holes. Start the
stopwatch at the same time, until all volatile matter escapes. The escape time shall not
be less than 2.5 min. Then take out the crucible. Do not cover the electric furnace during
this process.
7.3 Each coal specimen is tested three times in succession. After three tests, carefully
pour out the coke residue from the crucible. Measure the coke shape after the coke
residue cools to room temperature. If the range of three measured values exceeds 1/2,
it shall add two single tests. If the range of the five measured values exceeds 1, it shall
check the equipment, to make 5 repeated measurements.
Note: Between two tests, cover the electric heating furnace cover, to bring the furnace
temperature back to the preset temperature as quickly as possible.
7.4 After the test is completed, burn off the residue on the crucible and crucible cover;
wipe them clean.
8 Result expression and reporting
8.1 Crucible swelling number of coal sample
The crucible swelling number of the coal sample is determined and expressed according
to the following method:
a) Swelling number 0: Coke slag is not sticky or powdery;
b) Swelling number 1/2: The coke residue adheres to t...