GB/T 5448-1997 Determination of crucible expansion number of bituminous coal - Electric heating method

This standard specifies the determination method, instrumentation, test procedures and result presentation of crucible expansion number. This standard applies to bituminous coal. GB/T 5448-1997 Determination of crucible expansion number of bituminous coal - Electric heating method GB/T5448-1997 Standard download decompression password: www.bzxz.net

ICS73.040
National Standard of the People's Republic of China
GB/T5448-1997
eqvIS0501-1981(E)
Determination of the crucibleswelling number of bituminous coal-Electrical heating
1997-04-17 Issued
1997-10-01 Implementation
State Administration of Technical Supervision Issued
GB/T5448-1997
This standard is a revision of GB/T5448-85 "Determination of free expansion number of bituminous coal - Electric heating method" based on the international standards ISO501-1981 "Determination of coal-gas expansion number" and GB483-87 "General provisions for coal quality analysis test methods". The main technical contents of GB/T5448-85 are retained in the revision. ISO501-1981 has two heating methods: gas heating and electric heating. These two heating methods are equivalent. Considering the actual situation in my country, this standard stipulates the use of electric heating method. In terms of technical content, this standard is equivalent to the international standard. This standard will replace GB/T5448-85 from the date of entry into force. This standard is proposed by the Ministry of Coal Industry of the People's Republic of China. This standard is under the jurisdiction of the National Coal Standardization Technical Committee. The drafting units of this standard are Huangdao Commodity Inspection Bureau, Lianyungang Commodity Inspection Bureau, Kailuan Mining Bureau, Zaozhuang Mining Bureau, and Beijing Coal Chemistry Research Institute. The main drafters of this standard are Liu Liang, Ma Zhou, Qin Jingying, and Duan Shirui. This standard is entrusted to Beijing Coal Chemistry Research Institute of China Coal Research Institute for interpretation. 1 Scope
National Standard of the People's Republic of China
Determination of the crucibleswellingnumber ofbituminous coalElectrical heating
GB/T5448-1997
Replaces GB544885
This standard specifies the determination method, instrumentation, test procedures and result presentation of the crucible swelling number. This standard applies to bituminous coal.
2 Referenced standards
The following standards contain clauses that, through reference in this standard, constitute the clauses of this standard. When this standard was published, the versions shown were valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB474-1996 Preparation of coal samples
3 Summary of methods
Place the coal sample in a special furnace and heat it to (820±5)℃ according to the prescribed procedure. The resulting coke block is compared with a set of standard coke blocks with serial numbers, and the closest coke type serial number is used as the expansion serial number. 4 Instruments and equipment
4.1 Electric heating furnace (see Figure 1)
The structure of the electric heating furnace is as follows: A nickel-chromium wire coil with a power of 1000W is wound on a grooved refractory board (1) with a diameter of 100mm and a thickness of 13mm. The refractory plate is placed on a plate (2) of the same specifications. A quartz dish (3) with a wall thickness of 1mm, a height of 10mm and an outer diameter of 85mm is placed on the plate (1) to place the crucible.
The above-mentioned heating part is placed in a refractory brick (4) with a diameter of 140mm and a groove with a depth of 60.mm and a diameter of 105mm. The top is covered with a 20mm thick refractory plate (5). There is a hole with a diameter of 50mm in the center of the plate for insertion. The entire refractory brick is placed on an asbestos board (6) with a thickness of (3-5)mm. Insulating materials are filled around the brick and between the furnace shell (7). There is a refractory cover (8) on the top of the furnace and a hole at the bottom. The temperature measuring thermocouple (9) is inserted from the hole until its hot contact just contacts the inner surface of the quartz blood. The electric heating furnace is equipped with a suitable transformer and ammeter. Approved by the State Bureau of Technical Supervision on April 17, 1997 and implemented on October 1, 1997bzxZ.net
GB/T5448-1997
1, 2, 5-Refractory board 3-Quartz steel; 4-Refractory brick: 6-Stone ladder plate; 7-Shell: 8-Refractory cover; 9-Thermocouple
Figure 1 Electric heating furnace
4.2 And crucible cover (see Figure 2).
Made of high temperature resistant (greater than 1000℃) porcelain or quartz, specifications are as follows: 4.2.1 Crucible: top outer diameter (41±0.75) mm; bottom inner diameter not less than 11 mm; total height (26±0.5) mm, volume (16~17.5) mL, mass (11~12.75) g
Outer 1 Upper 0.75
1 Thousand 92
Figure 2 Crucible and Crucible Cover
Tower Crucible Cover with Hole
4.2.2 Crucible Cover: Inner Diameter 44 mm Height 5 mm
CB/T5448-—1997
4.2.3 Crucible Cover with Hole, same size as above, with a 6 mm diameter round hole for inserting thermocouple. 4.3 Thermocouple: Armored nickel-chromium thermocouple, 2 pcs. 4.4 Balance: Sensitivity 0.01g.
4.5 Stopwatch.
4.6 Weight: 500g flat bottom weight.
4.7 Coke block observation tube (see Figure 3).
Inner $40
Figure 3 Coke block observation tube
5 Test preparation
5.1 Sample preparation: Prepare air-dried coal samples with a particle size of less than 0.2mm in accordance with GB.474. During sample preparation, the coal samples should be prevented from being ground too finely. After the sample is prepared, it should be tested as soon as possible, otherwise it should be sealed and refrigerated, and the test cycle shall not exceed 3d. 5.2 Instrument debugging: Turn on the electric heating furnace, heat it to about 850℃ and keep it constant. Open the furnace cover, put a cold air into the center of the quartz blood in the furnace (start the stopwatch at the same time), immediately cover the crucible cover with holes, and then insert the thermocouple into the crucible through the cover hole, and press its hot contact against the inner surface of the bottom of the crucible. Observe the temperature rise without covering the electric furnace cover. If the temperature of the bottom of the crucible reaches (800 ± 10) °C within 1.5 minutes after the cold crucible is put in, and reaches (820 ± 5) °C within 2.5 minutes, then record the furnace temperature and current and voltage adjustment method, and control it according to this method when conducting the test. If the above requirements cannot be met, adjust the voltage, current and furnace temperature until the above requirements are met. 6 Test steps
6.1 Weigh (1 ± 0.01) g of air-dried coal sample, put it in and shake it flat, then on a rubber plate with a thickness of not less than 5 mm, use the five fingers of your hand to grab the crucible containing the coal sample downward, lift it to a height of about 15 mm, and then let it fall freely. This is done for 12 times in total (rotate the crucible by one angle each time it is dropped).
GB/T5448—1997
6.2 Open the furnace cover, place the crucible containing the coal sample into the center of the quartz furnace heated to the predetermined temperature, and immediately cover it with a crucible cover without holes (start the stopwatch at the same time) until the volatiles are exhausted, but not less than 2.5 minutes. Then take out the crucible. The electric furnace cover is not covered during this process.
6.3 Each coal sample is tested 5 times in succession. In the interval between two tests, the electric heating furnace should be covered to prevent heat loss. 6.45 After the test is completed, pour out the coke residue in the snail carefully, and determine the coke type after the coke residue cools to room temperature. 6.5 Remove the residue on the crucible cover by burning, and wipe it with a clean cloth. 7 Expression and report of results
7.1 The crucible expansion number of the coal sample is expressed as follows: a) Expansion number 0. The coke residue is not sticky or powdery. b) Expansion number -
load, i.e. crushed.
: coke residue sticks together into coke block and does not expand. Place the coke block on a flat hard board and carefully add 500g weight. c) Expansion number 1: coke residue sticks together into coke block and does not expand. After adding 500g weight, it cannot be crushed or breaks into 2-3 hard coke blocks. d) Expansion number 1
9: coke residue sticks together into coke block and expands. Place the coke block under the coke cake observation tube, rotate the coke block, find the largest side shape, and then compare it with a set of standard coke block side shapes with serial numbers (see Figure 4). Take the closest standard side shape as its expansion number. Figure 4 Standard coke block side shape diagram and its corresponding exhaustion expansion number 7.2 Result report:
If the test results of the same coal sample are within tolerance for 5 times, the average value of the 5 results shall be taken and reported rounded to 1/2 unit, and the digits after the decimal point shall be rounded up to 3 (i.e. 2 is rounded to 0 and 3 is rounded to 5). If the result is out of tolerance, the test shall be repeated. 8 Method precision
GB/T5448—1997
Repeatability limit: The range of 5 measurements in the same laboratory shall not be greater than 1 unit. Reproducibility critical difference: The difference between the average values ​​of multiple measurements in different laboratories shall not exceed 1 unit
National Standard of the People's Republic of China
Determination of the expansion number of bituminous coal crucible
Electric heating method
GB/T5448-1997
Published by China Standards Press
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Tel: 68522 112
Printed by China Standard Press, Qinhuangdao Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Sold by Xinhua Bookstores in various places, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 1/2 Number of words 8,000 words First edition in October 1997 First printing in October 1997 Number of copies 1-800
Book number: 155066: 1-14086
Price 8.00 yuan
Standard date 318-045
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