ABSTRACT
This paper aims to explore the disseminated characteristics of minerals in this kind of middling coking coal as the washed middling coal of some coking coal preparation plants is still difficult to disassociate after deep crushing. The difficult-to-dissociate middling coking coal was carefully prepared, the optical microscopy and scanning electron microscopy incorporated with energy dispersive spectroscopy (SEM-EDS) measurements of the middling coking coal were conducted to analyze the disseminated granularity and form of minerals in the middling coking coal. The results show that the minerals that are difficult to disassociate from middling coking coal are mainly clay minerals such as kaolinite, which was in the forms of fine granules, strips, disseminated, filled fissures, and cavities. The particle size of the disseminated clay minerals in the coal sample was only a few microns or even smaller. In addition to clay minerals, the minerals such as pyrite, calcite, and quartz were also observed in the middling coking coal. These minerals accounted for a relatively small proportion, but their grain sizes are very fine and their disseminating forms are very complex.