Apr 24 2014
Mining companies conduct development drilling before embarking on a mining project. Development drilling is performed to establish precise estimates of mineral reserves. This is performed once an ore body has been identified.
In many underground mines, horizontal development is common. New technology is always welcomed by mining companies to help improve development rates.
Generally, in development drilling, excavation of waste rock and ore retrieval are performed using drill holes and explosives, to break the ground for removal.
Excavation work in development drilling is based on certain parameters, such as pull-out and advancement per round. Pull-out can be defined as the percentage of the drilled round’s length that has been progressed after the blast. Likewise, the advance per round can be defined as the distance advanced in the tunnel after the blast. The length of the round is the perpendicular depth from the plane where the holes begin, to the plane where the holes end. Round length is a crucial feature in designing excavation work, as any future excavation advancement will depend upon an optimal round length. Hole distances are planned according to the type and amount of explosives used, or vice versa. Successful blast, and higher advance per round, in the excavation operation would mean saving time and money for the company. Any inaccuracies in the hole length can cause problems during blasting, and cause unevenness in the tunnel walls, back, and floor.
These days mining companies have the option of using computer-assisted drilling. It provides a complete navigation and aiming tool that can accurately execute pre-designed drilling plans.
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