Wide angle X-ray scattering study of the layering in three of the Argonne premium coals

Using wide angle X-ray scattering methods, the phase interference curves and the inter-layer structure curves of thee of the Argonne Premium Coals were measured. These analyses indicate the inter-layer structuring is rank dependent. In the sub-bituminous coal (Wyodak–Anderson), the number of layers in the average short-range structural domain is ca. 2.3, with the average inter-layer distance being 4.1 Å. For Pittsburgh #8 coal, the average inter-layer distance decreases slightly, to 4.0 Å, while the number of layers in the average short-range structural domain increases to ca. 3. For the more mature Pocahontas #3, a low-volatile bituminous coal, the inter-layer distance decreases to 3.7 Å, and the average short-range structural domain contains 4.5–5 layers.