Coal is as variable as the conditions in the mire, during and after peat accumulation. Many classification systems have been developed so that the coal is used appropriately. Traditional coal classification schemes, such as the rank-based system of ASTM D388 (ASTM, 1996a) or the original ISO (United Nations Economic Commission for Europe) International Classification of Hard Coals by Type, were developed using one type of coal, specifically, vitrinite-rich coals. The goal of international codification systems has always been to provide a uniform basis for the understanding of the range of coal properties while accounting for the differences between coals of different origins, such as between the Carboniferous Laurasian (Northern Hemisphere) and the Permian Gondwana (Southern Hemisphere and India) coals.
The United Nations Economic Commission for Europe endorsed a codification for bituminous- and anthracite-rank coals in 1988 (United Nations, 1988). While not quite satisfying all of the needs of the major Gondwana exporters (Australia and South Africa) owing to the dependence upon vitrinite properties, the system is more universal than any previous codification. The international system codifies coals by means of a 14-digit number based on eight coal-quality parameters (Table 10):
Figures & Tables
This volume of the “Atlas of Coal Geology” provides 393 images on various subject matters related to coal deposits and coal resource utilization. The supporting text provides an introductory overview of coal exploration, mining, and coalbed methane (CBM) development, followed by discussions on various megascopic aspects of coal geology (microscopic aspects are covered in Volume 2). Because of the vast subject matter, many generalities had to be made in the text. References are included to guide those interested to more detailed discussions. All citations within the document are linked to the detailed reference list for this volume. The overriding theme for this publication is that a picture is worth a thousand words.