Exploration drilling Serbian style - Atlas Copco

Operator Eduardo Macheo: “I like this machine. I’ve
been able to drill 780 meters with it in one 12 hour
shift and I think I can do better.”
engine that delivers 1 650 hp at 1 800 rpm,
as well as a larger compressor – 3 800 cfm
(110 psi/ 7.6 bar) instead of 3 000 cfm.
The high altitude of this region also
means extreme cold, especially in winter
(July to September), when temperatures
often drop to –40 C°. “As a result, the rigs
also have to be fitted with a heater and an
on-board generator,” continues Espindola,
adding that the performance of other items
such as the water pump, fuel, battery and oil
can all be affected by the low temperature.
The rock at Collahuasi has an average
compressive strength of 100 MPa with
some sectors reaching even 250 MPa. For
comparison, the rock at other local mines
has a typical strength of 60 MPa.
Blasting is carried out once a day and
four different drilling patterns are used,
depending on the area. The presence of
water decides whether heavy ANFO or
ANFO and emulsion explosive is used.
Atlas Copco also supplies all consumables
such as rotary bits (including Secoroc
Tricone bits), drill pipes, bit adaptors, top
sub adaptors and rotary deck bushings.
Stealing the show
Although both rigs are performing well, it
is the larger PV-351 that appears to be stealing
the show. During M&C’s visit, this unit
was drilling about 10 percent faster than the
fleet’s electric rigs – roughly 58 m per hour
compared to an average of 50 m/h for the
electric rigs.
This was confirmed by the operator
Eduardo Macheo. “I like this machine,” he
said. “It’s fast and I’ve been able to drill 780
meters with it in one 12 hour shift, including
a one hour break, but I can do better.
My personal record is 800 meters in one
shift and I’m sure I can reach that with the
PV-351,” he laughs confidently.
Macheo was familiar with this rig from
the start having previously worked on a Pit
Viper 271 at another copper mine, although
not equipped with the Atlas Copco Rig
Control System (RCS).
“Before I came here I had the opportunity
to operate the PV-271. I had a console,
not joysticks, so the joysticks and the whole
computerized system were a new experience
for me.”
The RCS computerized system is standard
on all PV-351 rigs and provides a
high level of automation, including options
like autodrilling, GPS hole navigation,
rig remote access with communication,
remote tramming, Measure While Drilling,
tele-remote operation and other advanced
features.
All the functions are controlled through
a touch screen, two joysticks and pushbuttons
on the operator’s seat, so when
the seat swivels, so do the joysticks and
screen.
When the two Pit Vipers arrived at
the mine, Atlas Copco provided two
Best on site: The PV-351 has proved that
it drills faster than the electric rigs in the
Collahuasi fleet.
Mining & Construction – 1 / 2012 5