scope:

Introduction

Coal is a very heterogeneous material containing various combinations of organic matter and mineral matter. The principal elements in the organic matter are carbon, hydrogen, nitrogen, sulfur, and oxygen. The mineral matter may contain detectable quantities of as many as 60 elements, which together make up the various minerals found in coal. These minerals include clay minerals, pyrite, marcasite, calcite, silica, and smaller amounts of other minerals. However, the analysis of coal is generally determined from representative samples of the material and not from the individual components. Typical analysis ranges of important analytical parameters (as-received basis) for the principal ranks of coal are given in the table that follows [1]. (In this table and throughout this text all percentages are percent mass fractions unless otherwise noted.) The values for oxygen and hydrogen in this table include the hydrogen and oxygen values for sample moisture. Another common practice is not to report the hydrogen and oxygen in the sample moisture as part of the hydrogen and oxygen values for the coal.