Geomechanics Study of Ore and Host Rocks for Narrow Vein Mining

ABSTRACT: In Sustainable Mining by Drilling (SMD) method, mining excavation commonly transfers from open pit mining to drilling excavation based on the cost and efficiency. Mining drilling is generally conducted on narrow veins, along with next-step excavation using the hole-widening drilling. To obtain the maximum production, a comprehensive study is required for planning drill-off tests (DOT) aiming at the highest rate-of-penetration (ROP) or material-removal-rate (MRR). In Drilling Technology Laboratory (DTL), geomechanics parameters of ore and host rocks were obtained by a series of geomechanics tests. These parameters include peak strength, Young’s modulus, acoustic properties, abrasiveness and hardness. Investigated rocks include argillite, altered mafic, high-pyrite mafic, ordinary mafic and quartzite. Core were drilled and compared from directions parallel and perpendicular to the bedding. In Pine Cove Deposit, high-pyrite mafic cores parallel to the beddings are stronger than that perpendicular to the beddings due to some existing quartz between beddings. In Romeo & Juliet Vein, mafic volcanic has much higher strength than that in Pine Cove Deposit. These geomechanics parameters assist in designing on-site DOT for the optimum production.