Geostatistical modelling of coal quality parameters has not been widely adopted in Indonesia. Geostatistical interpolation of non-assay data allows the mine planner to estimate quality parameters regarding mining. The foresight can then be used for more timely and accurate seam blending protocols. This paper discusses the modelling and the spatial variability of three coal parameters, namely calorific value, ash content, and sulphur content, of a coal seam in Malinau, East Kalimantan, Indonesia. It is concluded that the use of the kriging procedure is strongly influenced by the amount of drill-hole data and their areal distribution. The results are more realistic when more drill-hole data are available and the distribution is even. It is thus worthwhile to consider the inclusion of geostatistical methods into mine planning as they can identify the errors associated with large reserve tonnage and quality estimates when used appropriately. The use of these methods could be a good opportunity to enhance mine planning in Indonesia.
Keywords: geostatistical models, coal kriging, coal quality prediction, Indonesia