Deployment of a multiple-dragline fleet to extract thick coal seams under deep overburden [Derin örtü alti{dotless}ndaki kali{dotless}n kömür damarlari{dotless}ni{dotless}n çi{dotless}karti{dotless}lmasi{dotless}nda çoklu çekmekepçe örtükazi{dotless} sistemlerinin kullani{dotless}mi{dotless}]

Abstract

This study addresses the use of combined stripping systems to investigate the technical feasibility of extracting level -lying thick coal seams underlying deep overburden strata. The possibility of using multiple draglines in tandem with bucket wheel excavator systems is explored. Considering the depth of overlying strata, application of terrace mining and excavation of a large part of the overburden by employing a triple dragline excavation fleet, two of which are deployed on the highwall side and the third one on the spoil side, is planned. The uppermost part of the overburden is to be excavated and transported across the pit via a bucket wheel excavator-cross pit spreader sub-system. With approximately 4×109 t of lower-calorific value of lignite reserves, Afşin-Elbistan lignite basin holds a large potential for electrical energy production in Turkey. The basin is divided into sectors of approximately 750×106 t lignite tonnages. Based on average coal and overburden thickness terms a 25×106 t of lignite production per annum is projected with some 50×106 m3 of overburden to be moved. A production simulation algorithm, which emphasizes synchronizing excavator units in the triple dragline system, is developed. The model is tested with the data from Sector-D of Afşin-Elbistan lignite basin and several dragline-BWE-XPS combinations that may successfully perform overburden stripping at the predetermined rate and uncover coal seams are obtained.