A. Soltani Khaboushan; M. Osanloo
Abstract
Due to the gradual deepening of the Mazinu coal seams from the ground surface, both the open-pit (OP) and underground (UG) mining methods can be applied for extracting them. Thus, it is a necessity to determine the interface of these mining methods optimally. The present paper aims to determine this ...
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Due to the gradual deepening of the Mazinu coal seams from the ground surface, both the open-pit (OP) and underground (UG) mining methods can be applied for extracting them. Thus, it is a necessity to determine the interface of these mining methods optimally. The present paper aims to determine this interface by generating different scenarios using the OP phases and their relative underground stopes, and comparing them with each other. In this regard, an economic block model is created based on the calorific value of the coal portions involved by each block along with the required economic and technical parameters. Then using the Lerchs-Grossman algorithm, the OP phases are created. Proportional to each phase, the production scheduling of underground stopes is executed. Finally, in order to opt the best scenario, the net present value of the whole project (OP & UG) achieved from different scenarios are compared with each other. The results obtained indicate that the optimum interface of the OP and UG mining activities correspond to the ultimate OP limit with a maximum depth of 200 m from the ground surface.
ebrahim elahi; Reza Kakaie; amir yusefi
Abstract
Ultimate limits of an open pit, which define its size and shape at the end of the mine’s life, is the pit with the highest profit value. A number of algorithms such as floating or moving cone method, floating cone method II and the corrected forms of this method, the Korobov algorithm and the corrected ...
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Ultimate limits of an open pit, which define its size and shape at the end of the mine’s life, is the pit with the highest profit value. A number of algorithms such as floating or moving cone method, floating cone method II and the corrected forms of this method, the Korobov algorithm and the corrected form of this method, dynamic programming and the Lerchs and Grossmann algorithm based on graph theory have been developed to find out the optimum final pit limits. Each of these methods has special advantages and disadvantages. Among these methods, the floating cone method is the simplest and fastest technique to determine optimum ultimate pit limits to which variable slope angle can be easily applied. In contrast, this method fails to find out optimum final pit limits for all the cases. Therefore, other techniques such as floating cone method II and the corrected forms of this method have been developed to overcome this shortcoming. Nevertheless, these methods are not always able to yield the true optimum pit. To overcome this problem, in this paper a new algorithm called floating cone method III has been introduced to determine optimum ultimate pit limits. The results show that this method is able to produce good outcome.
