Optimization of Dump Bench Configuration to Improve Waste Dump Capacity of Narynsukhait Open Pit Coal Mine

Abstract

In next two years, the current waste dump of Narynsukhait coal mine is predicted insufficient to accommodate the overburden as limited of the waste dump capacity. Thus, redesigning waste dump is paramount to increase capacity of the dump in future. This paper describes current condition of waste dump of Narynsukhait coal mine and then discusses the optimization of waste dump geometry by analyzing the effect of different waste dump’s bench configuration on slope performance. Optimization of the geometry is carried out by investigating and comparing the performance of geometrical combinations of bench height, bench angles and number of safety berm by means of numerical modeling. The model shows that increasing height of bench is able to induce shear stress in the bench and may initiate bench instable. However, the shear stress can be limited by having safety berm and/or reducing bench angle to satisfy the stability criteria.