Seam C1A2 Group coal rank analysis in East Meranti PIT, Katanjung Village, Kapuas Regency based on proximate values

Coal is an organic rock originating from plant matter that undergoes decomposition (diagenesis/biochemical process), increasing carbon (C) content, calorific value, and rank. Kalimantan Island is one of the islands with the largest coal reserves, reaching 19.27 billion tons. The research area is located at the PT Sembilan Tiga Perdana coal mining site in Katanjung Village, Kapuas Regency, Central Kalimantan Province. The research area covers an area of approximately 1.1 hectares and is situated about 38 km east of Kuala Kurun, Gunung Mas Regency, Central Kalimantan. This research aims to analyze the coal rank of the C1A2 seam group at East Meranti Pit, Katanjung Village, Kapuas Regency, based on proximate values. The research methodology consists of direct field surveys and laboratory methods. Field surveys include surface and subsurface surveys, while laboratory methods comprise petrological and proximate analyses. The determination of coal rank refers to the ASTM (American Society for Testing and Materials) classification. The results and discussion of the research indicate the presence of one anthropogenic geomorphological unit. The research stratigraphy consists of two units: laminated sandstone unit and interbedded sandstone-claystone unit. The lineament pattern trends north-south direction. The calculated calorific value of the C1A2 seam group coal is 13,388 btu/lb, categorizing it as high-volatile B bituminous coal.