Exploration drilling Serbian style - Atlas Copco

M&C in Latin America >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Drilling with a smile: Operator Victor Astudillo at the controls of the Pit Viper 271 in the Veladero pit.
Dependin g on the area, a hole can take from 18 minutes up to one hour to complete.
Close to the Chilean border, about 350 km
northeast of the city of San Juan, is the
Veladero gold mine operated by Minera
Argentina Gold, a subsidiary of Barrick, one
of the world’s leading gold producers.
Located at 4 000–4 850 m above sea
level, the mine can only be accessed via
a 156 km road which sometimes reaches
heights of more than 5 000 m. It takes about
seven hours to drive and conditions in winter
can be so severe that shelters have been
built every 20 km to protect workers and
travellers from the elements.
At this altitude, the temperature drops
2 C° for every 300 m of elevation. In winter,
the temperature averages –10° C during the
day, dropping as low as –16° C at night, or
even as low as –40° C with the wind chill.
The winds can be very strong, sometimes
80–100 km per hour and extreme
winds of up to 220 km per hour have been
recorded by the weather station, says Mining
Superintendent Jose Luis Fornés,
Winter can be so harsh that the road is
often blocked, prompting the mine to adopt
emergency measures and it also has its
own operating theatre and surgeon should
a medical problem occur while the road is
closed. Added to this is the constant threat
of violent thunderstorms.
Complicated logistics
So what does such a harsh, unpredicatble
environment mean for the equipment
“The special conditions here complicates
our logistics,” admits Fornés. “This is a
very remote site. There’s nothing within a
100 km radius so we expect reliability from
our equipment and suppliers.”
The drilling fleet consists of 11 diesel
powered rigs including an Atlas Copco Pit
Viper 271. It is deployed in Pit Amable,
drilling 105/8" production blastholes. The
mine uses standard 15 m high bench drilling
with a hole spacing of 7x8 m in waste rock
and 6.5x7 m in ore.
A sturdy and powerful blasthole drill rig,
the PV-271 features a pulldown force of up
to 311 kN (70 000 lbf) and a 34 tonne bit
load capacity for maximum productivity in
hard rock formations.
The rock here is of silica-type and varies
in quality throughout the site. “We have
areas where the rock is hard, others where
it is quite fragile and others where it is not
only hard but also highly abrasive,” says
Ramón Arjona, Drilling & Blasting Senior
Supervisor.”
Victor Astudillo, operator of the PV-271,
knows this only too well. He explains that
depending on the area where they are working,
drilling a production blasthole can take
from 18 minutes to one hour. “Most of the
8 Mining & Construction – 1 / 2012