This standard specifies determination of total moisture in coal in terms of method summary, reagents and materials, apparatus, sample, procedure, result calculation, method precision and test report.
In this standard, drying under nitrogen (Method A1 and Method B1) is suitable for all coals while drying in air (Method A2 and Method B2) is suitable for soft coal (excluding coals susceptible to oxidation) and blind coal.
In this standard, Method A1 serves as an arbitration method.
Note: this standard also provides drying in microwave for quick determination of full moisture and this method is suitable for soft coal and lignite, as shown in Annex A.
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 (including any amendments) applies.
GB/T 212 Proximate Analysis of Coal
GB/T 474 Method for Preparation of Coal Sample
GB/T 19494.2 Mechanical Sampling of Coal Part 2: Method for Sample Preparation
3 Method Summary
3.1 Method A (two-stage method)
3.1.1 Method A1: drying in nitrogen
Some amount of 13mm sample is weighed and dried at temperature not exceeding 40℃ until mass is constant, crush the air-dried sample to 3mm nominal top size and then dry it in a nitrogen flow at 105℃~110℃ until mass is constant. Full moisture is calculated by the mass loss of sample after two-stage drying.
3.1.2 Method A2: drying in air
Some amount of 13mm sample is weighed and dried at temperature not exceeding 40℃ until mass is constant, crush the air-dried sample to 3mm nominal top size and then dry it in an airflow at 105℃~110℃ until mass is constant. Full moisture is calculated by the mass loss of sample after two-stage drying.
