Dados do Trabalho

Título

OPTIMIZING STOPES AND RIB PILLARS IN SUBLEVEL OPEN STOPING MINING METHOD: AN AUTOMATED NUMERICAL MODELING APPROACH

Resumo

The top-down extraction sequence in the sublevel open stope method leaves rib pillars to support the excavations, making dilution control critical. This study introduces an integrated methodology for optimizing net profit and geomechanical performance of open stope layouts and rib pillars using a genetic algorithm. User-informed parameters such as minimum stope size, minimum pillar size, maximum accepted dilution, and maximum acceptable percentage of pillar failure are considered. A graphical user interface (GUI) was created to make its application easier. A profit function, capable of assigning economic value to the analyzed geometric configuration, including geomechanical performance, is developed. Geomechanical performance of the geometric configurations is determined through autonomous numerical models in FLAC3D software, which include average percentage of pillar failure and potential dilution. The algorithm's validity is demonstrated through a case study involving a mining panel in an underground gold mine. An 8% increase in net profit relative to the engineer’s design method was achieved, assuming 70% hangingwall support efficiency for both methods. Pillar failure percentage decreased threefold. When no HW support is considered, the net profit increase is 22% compared to the engineer’s design method. This methodology showcases the feasibility of integrated optimization, considering mining costs and geomechanical performance costs, thereby reducing the need for secondary support.

Palavras-chave

stope optimization, dilution, hangingwall, pillar failure, FLAC3D

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