GB/T 5448-2014 Determination of the crucible swelling number of bituminous coal — Electrical heating method
1 Scope
This standard specifies the principle, apparatus, test preparation, test procedures, expression of results, precision of method and test report for determination of the crucible swelling number (CSN).
This standard is applicable to bituminous coal.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 474 Preparation of coal sample
GB/T 483 General rules for analytical and testing methods of coal
3 Principle
Place the coal sample in a special crucible and heat it to (820±5)℃ in accordance with the prescribed procedure. The shape of the coke button obtained is classified by comparison with the outlines of a set of standard profiles, and the closest coke button type serial number is taken as the crucible swelling number.
4 Apparatus
4.1 Electric heating furnace (Figure 1)
A nickel-chromium wire coil with a power of 1000 W is wound on a grooved fire-resistant plate with a diameter of 100mm and a thickness of 13mm. The fire-resistant plate is placed on a plate of the same specification. On plate 1, there is a quartz dish with a wall thickness of 1mm, a height of 10mm and an external diameter of 85mm, which is used to hold the crucible.
The above heating parts are placed in a refractory brick with a diameter of 140mm, featuring a groove that is 60mm deep and 105mm in diameter, and is covered with a 20mm thick refractory board on top. There is a 50mm diameter hole in the center of the plate for placing a crucible. The entire refractory brick is placed on a 3mm to 5mm thick asbestos board, and insulation materials are filled around the brick and between the furnace shell. There is a refractory cover on the top of the furnace and a hole is opened at the base. Insert the temperature-measuring thermocouple through the hole until its thermal contact point exactly touches the inner surface of the quartz dish. The electric heating furnace is equipped with appropriate temperature measurement and control devices.
4.2 Crucible and lid (Figure 2)
Made of porcelain or quartz that can withstand high temperatures (above 1000℃). Total height of the crucible: (26±0.5)mm; external diameter at top: (41±0.75)mm; internal diameter at base: 11mm to 14mm; mass: 11g to 12.75g capacity: 16mL to 17.5 mL; the internal diameter of crucible lid (without holes) is 44mm and the height is 5mm.
4.3 Pierced lid (Figure 3)
Made of porcelain or quartz that can withstand high temperatures (>1000℃). Similar to that described in 4.2 but with a 6mm hole through which the thermocouple can pass.
4.4 Thermocouple
Armored nickel-chromium thermocouples, 2 pieces.
4.5 Coke button observation cylinder (Figure 4)
The coke button observation cylinder shall meet the requirements of Figure 4.
4.6 Weight
Contents
Foreword II
1 Scope
2 Normative references
3 Principle
4 Apparatus
5 Preparation of test sample
6 Preparation of apparatus
7 Procedure
9 Precision of method
10 Test report
Annex A (Informative) Structural changes of this standard with respect to ISO 501:2003
Annex B (Informative) Technical deviations between this standard and ISO 501:2003 and their justifications
