Atlas Copco Easer L increases development rates at Deep SouthDecember 15, 2017
Fleet, Mine Development, Raise Boring, Western Australia
In 2016, Saracen Minerals’ Deep South gold mine in WA’s Goldfields transitioned to an underground operation.
The mine schedule had been heavily constrained by vertical development which, prior to the application of the Atlas Copco Easer L rig, had been carried out by conventional boxhole and raise bore rigs for escape ways, and air leg and longhole rises for stoping slots.
The use of the air leg rise increased the mine’s risk profile while longhole rises were blind and required to be fired in one shot; with the success rate of opening a slot being 70%.
Identifying a solution
PYBAR is committed to applying the latest proven technology to improve mine performance. In line with this, we proposed the application of our new Easer rig at Deep South, along with an operating crew.
“The Easer is a compact, dual purpose rig specifically designed to drill both conventional rises and boxhole slot rises while maintaining a low profile. Being wheel-bound, it’s exceptionally easy to move between drill sites and, unlike traditional raise bores, no site preparation or concrete foundation is required,” said Phil Viljoen, PYBAR’s Raise Bore Superintendent.
“It offered the client a solution to increase advance rates and improve mine production while reducing the risk of entry method slotting such as air leg rising and long hole slot drilling.”
The expertise of PYBAR’s Raise Bore Division and the support provided by Atlas Copco in the form of onsite fitters meant the team was able to implement the new technology quickly.
The vertical development rates achieved by the Easer were greater than anticipated.
The time to complete rises was faster than originally scheduled, and the associated costs of completing the works were in line with the budget.
The Easer completed 93 x 760mm stope slots and seven x 1.1m escape ways for a total of 2,329 metres in 15 months.
“In using the Easer, we were able to put the rises in at various angles to suit the orebody and the success of opening the slot was close to 100% which significantly improved the production profile at Deep South all whilst being safer than air leg slotting,” said Mr Viljoen.
The biggest advantages the Easer brought were flexibility and safety.
“In strike drives, the Easer was able to bore boxhole slots from the central access working toward the face, which then allowed the longhole rig to follow behind. This enabled two scheduling activities – slotting and production drilling – to occur at the same time rather than as two separate and dependent activities,” said Mr Viljoen.
Its ability to rapidly relocate and setup on a new location reduces the delay between holes as there is no requirement for a concrete pad and the associated rig up / rig down process, saving both time and costs, and reducing manual labour.
The Easer also mitigated the risk of stope bridging when blasting versus otherwise conventional drill and blast applications.
Raising the bar
Through the use of the Easer, Deep South was able to safely achieve a sustained improvement in its vertical development rate in stoping slots and escape way rises.
The rig proved itself as a fast and flexible solution to vertical development and a value adding resource, setting the benchmark for future vertical development expectations at the mine.