Seam modeling and resource estimation in the coalfields of western Anatolia

Western Anatolia, Turkey includes a number of lignite-bearing Neogene fields with difficult modeling and estimation problems resulting from severe tectonic movements and highly variable coal quality. The paper considers the Eynez–Soma and Ömerler–Tunçbilek coal fields and introduces a simple but effective way of defining the geological discontinuities that are vital for selective mining method. After doing statistical analysis for both fields, data taken from core samples of diamond drill holes are used to model fault blocks in order to establish a 3D coal seam model. Then block (small mining unit) modeling is performed for both coal fields and some coal quality parameters are estimated and assigned to the predefined blocks. For estimation process, a new method of wrinkling and unwrinkling is introduced and composited data is detrended. Each block is kriged by using the detrended data in unwrinkled space. The volume of the blocks is converted into in-situ tonnages based on their estimated densities. In Eynez the densities are derived from the mean lower calorific value of the blocks using the relationship between lower calorific value and density. In Ömerler the block densities are estimated from the composited values of densities of the lithologic units in coal horizon by using ordinary kriging. ► A correct data base is the essence of all modeling and estimation works. ► A mine modeler must be involved in solid modeling. ► Unwrinkling maintains the correct spatial relations. ► Density is estimated on the basis of individual blocks.