MOISTURE OF GREEN PETROLEUM COKE: ASTM D4931
EXPLANATION
Moisture adds weight to coke and serves no useful purpose. Acknowledgement of moisture is thus important in the purchase and sale of green petroleum coke. This test method covers both the preparation procedure for samples containing free water, and the determination of the gross moisture content of green petroleum coke.
TEST SUMMARY
There are two procedures used. Preparation Procedure is used when the petroleum coke sample contains free water. The sample is weighed and air dried to equilibrate it with the atmosphere. Determination of the residual moisture is then determined using the Drying Oven Method. Air drying and residual moisture are combined to report gross moisture.
The Drying Oven Method is used in routine commercial practice when the sample does not contain free water. The sample is crushed to at least -25 mm 1 in. top sieve size and divided into aliquots of at least 500 g each.
TEST PRECISION
Repeatability: 0.34 %
Reproducibility: 0.58 %
The bias of this test method is not known.
