IDENTIFICATION OF MINERAL CHARACTERISTICS ON COAL WITH SCIENTIFIC APPROACH OF XRD ANALYSIS AND SEM-EDS ANALYSIS

Abstract

Coal minerals can form either singenetically or epigenetically associated with coal.
Overall the material in coal is divided into three classes: minerals in the form of
crystalline and discrete particles, inorganic elements or compounds bonded with coal
molecules (excluding nitrogen and sulfur) and inorganic compounds dissolved in pore
water and surface water of coal. In the identification of mineral characteristics three
scientific approaches are X-Ray Diffraction (XRD), Scanning Electron Microscope
(SEM) and Energy Dispersive Spectroscopy (EDS). Based on the results of X-Ray
Diffraction (XRD) analysis found some clay minerals and sulphate. Minerals encountered
in coal samples include quartz, kaolinite, Kutnohorite, magnesian, melanterit, zaherit and
beidellite. Beidelllite is a transformation of smectite, melanterit is a sulfate mineral
formed from oxidized of pyrite. While the results of the Energy Dispersive Spectroscopy
(EDS) analysis of the elements are believed to be similar to the existing elements in
meneral XRD analysis results are reinforced by SEM analysis that shows the appearance
of mineral morphology such as kaolin flakes, melanterit and framboidal pyrite.