ASTM D2797/D2797M-21 PDF Download

The methods for preparing granular samples of bituminous coal and anthracite for microscopic examination under reflected light illumination are described in ASTM D2797/D2797M-21, a standard process. This technique is used to produce briquets with flat, scratch-free surfaces ideal for microscopical inspection. The particles in these briquets should be an accurate representation of the original gross sample.

These samples are generally utilized for two microscopical analyses: the reflectance of the organic components in a polished specimen of coal (Test Method D2798) and the volume percent of physical components in coal (Test Method D2799). It is significant to note that the processing of orientated coal blocks is not covered by this accepted procedure.