Selecting the optimal exploitation option using a digital deposit model and the AHP

Abstract

The prime objective of the study was to identify and evaluate options for development and exploitation of a prospective hard coal deposit using a digital geological model and a multi-criteria decision-making approach allowed, in elaborated research process, to identify investment alternatives and outline the one that maximizes the benefits for the potential investor. The developed research methodology was based on decision criteria including: economic, technical, geological, social, and environmental aspects. The combination of the above criteria made it possible to create six options for the development of the deposit named as: 1.2 MAX and 1.2 EKO, 1.5 MAX and 1.5 EKO, and 1.8 MAX and 1.8 EKO. The Analytic Hierarchy Process (AHP) was used as a method to select the optimum investment option. The research process consisted in taking into account the positive and negative impacts of individual exploitation options by building four separate hierarchical models (BOCR analysis), i.e. Benefits (B), Opportunities (O), Costs (C) and Risks (R).Digital geological model of the existing and prospective deposit was a key source of information for AHP assessment process. The structural model of 15 seams of economic importance and a qualitative model of coal quality parameters were elaborated. The structural and quality models were prepared on the basis of lithostratigraphic profiles from 55 surface boreholes, 16 underground boreholes and 250 geological profiles of mine workings in the area of the existing coal deposit. These models constituted input for the assessment of economic efficiency of the above mentioned options. The digital model served as the basis for the creation of access, development and mining work schedules, and the developed simulations of mining exploitation were used to build a model of surface deformation considered as one of the most significant decision-making factor.The result of the work was formulated as a ranking of the analyzed scenarios, indicating the most attractive ones. In this case, and in terms of the adopted AHP methodology, the dynamic strategy scenarios is represented by ‘No additional shafts' scenario, 1.8 EKO, 1.8 MAX and 1.5 EKO scenarios. Their implementation fulfils the policy of sustainable depletion of the reserves of a prospective deposit, while maintaining environmental standards and high economic efficiency. The ‘No additional shafts' scenario represents the idea of rapid decommissioning of the mining industry, while scenarios 1.8 EKO, 1.8 MAX and 1.5 EKO are in turn scenarios of rational resources management allowing for gradual depletion of the deposit reserves in a long-term perspective.