CEMI
SUDBURY/NORTH BAY INNOVATION CLUSTER
seeks to accelerate advance rates
Canopy system designed to triple advance speeds By Doug Morrison
access more orebodies that are distant from an existing shaft, driving single-heading accesses over several kilometres will become commonplace. Getting to the orebody as soon as possible is crucial because it increases the net present value of the deposit so improving the rate of advance in access drift development is critically important. The activities in the conventional drillblast cycle (removing broken rock, installing ground support, drilling face holes and charging explosives) in a deep Canadian mine add up to about 16 hours. Given the availability of equipment and crews in a
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MINING JOURNAL
multi-heading setting, completing one cycle can take 36 hours. In simple terms this is about 3 metres per day and even a 16-hour cycle with centralized blasting would result in a rate of 4.5 metres per day. Mine contractors can progress faster because they manage a more efficient shift change and blast at will. Unfortunately, the effectiveness of the drill-blast process has decreased over time. Safety standards increased, accesses became bigger to accommodate larger equipment, and so has the need for more ground support because of the size increase, higher stresses and rockbursting at the face. Conventional drill-blast techniques responded poorly to these changes: installing face support every cycle to pro-
tect against face bursting reduced the advance rate to less than 3 metres per day. Concurrent face activities In our view at the Centre for Excellence in Mining Innovation (CEMI), one of the best ways to significantly increase the drill-blast advance rate in deep hard rock mines, is to introduce a system that allows concurrent activities to reduce the critical path cycle time. To be able to drill and charge the face while simultaneously installing ground support, the equipment and workforce in the heading requires temporary protection. We asked North Bay, Ont.-based Nordic Minesteel Technologies to build a set of canopies that would be strong enough www.canadianminingjournal.com
Photo: agnormark, iStockimages.com
ccess development is one of the Aunderground most important and expensive things mines do. As deep mines
