Selective mine plan based on coal quality distribution of Batu Ayau formation, Murung Raya-Central Kalimantan

Abstract

Coal quality, which eventually controlling coal’s behavior during preservation, combustion, and other forms of utilization, are defined by the depositional environment in which the peat was formed. Batu Ayau Formation is a well-known coal-bearing formation of Barito Basin and has been thoroughly explored. The aim of this study, which differs from previous studies, is to figure out the correlation of depositional environment to the coal quality of Batu Ayau Formation and anticipate the less desired coal quality from being mined. The depositional environment is determined through the stratigraphic section compared to Horne model, supported by coal facies determination using Tissue Preservation Index (TPI) vs Gelification Index diagram. Ash and sulphur content (weight %) data from 4 seams are integrated to the lithostratigraphic column. The coal quality distribution is defined from good correlation. The coal-bearing depositional environment of the studied area is transitional – upper delta plain. The ash content is ranging in 5.20-8.64wt% and total sulphur is ranging in 0.34-1.28%. The position of depositional environment that is closer to open marine, which is dipping westward, is preferable in terms of quality. Hence, coal on the center part of the research has preferable coal quality to be mined.