ASTM D6374 Standard Test Method for Volatile Matter in Green Petroleum Coke Quartz Crucible Procedure
10. Procedure
10.1 Ignite the quartz crucible and cover at 950 +/- 20°C for 5 min periods to constant mass (+/- 0.5 mg). Do not cover the crucible at this time to allow the carbon to burn off. Cool to ambient temperature in a desiccator before weighing the crucible and cover.
NOTE 1 - Placing the empty crucibles in the inverted cover when igniting will reduce breakage and chipping.
10.2 Avoiding segregation of particles, transfer 1 g +/- 10 mg of the analysis sample (see Annex A1) to the crucible, weigh the crucible with its contents, and cover to the nearest 0.1 mg. Place the cover on the crucible, and place in sample rack.
10.3 Set the timer for the analysis time (5 to 10 min). Place the rack in the furnace. Start the timer.
NOTE 2 - Place the rack in the center of the furnace. Do not allow the rack to touch the walls of the furnace.
10.4 After the analysis time (+/- 5 s), remove the rack from the furnace and immediately place on a heat sink.
10.5 Weigh the crucible after it has cooled to room temperature and before it has been at room temperature for longer than 20 min.
NOTE 3 - If cool down is not in a humidity controlled area, desiccation is required.
11. Calculation
11.1 Calculate the volatile matter of the moisture free prepared coke as follows:
Volatile matter, mass % = ((A - B))/C) x 100
where:
A = weight of crucible and prepared sample prior to analysis, g,
B = weight of crucible and prepared sample after analysis, g, and
C = weight of prepared sample, g.