Mining_Methods_UnderGround_Mining - Mining and Blasting

This joint development process started
with the 1998-1999 ramp extension
at Garpenberg North. The complex geo-
logy results in winding cross sections
of varying width, and ore boundaries
which are difficult to predict by core
drilling. To enable the drifts in the cut
and fill stopes to follow the paths of the
orebodies, accurate production maps
and precise drill rig navigation are es-
sential. Producing drill plans in the
office is relatively easy. However, getting
drill plans that match the actual ore
boundaries is a challenge, and frequently
the driller is obliged to improvize
while drilling, which can lead to poor
blasting results.
drill plan generator
The drill plan generator overcomes the
ore navigation problem by assisting the
operator to create an optimum drill plan
right at the face. In case the generated
drill plan does not match the actual ore
boundaries, the operator can define new
coordinates to correct the situation. To
do this, having aligned the feed to the
laser beam to define the position of the
rig, the operator points the drill feeds
at the four corners of the face, in line
with the geologist’s marks. When all
adjustments have been made, the Rig
Control System RCS will develop the
most efficient round compatible with the
new parameters. The generated drill plan
is automatically entered into the Rocket
Boomer L2 C ABC Regular standard
drilling system, and the operator can
start drilling. While drilling, each com-
pleted hole is logged, and, if the Measure
While Drilling (MWD) option is acti-
vated, the drilling parameters along the
hole are recorded. All of the data is log-
ged on the PC card for off-line processing
in the Tunnel Manager support program,
and is then transferred to the
mine database. As a result of the Drill
Plan Generator and ABC Regular,
Garpenberg North increased the size
of the production rounds from 400 t
to 600 t, reduced drilling time from 5
to 3 h/round, reducing costs of explosives,
scaling and rock support and,
most important, minimizing ore dilution.
Garpenberg now has one Rocket
Boomer L2 C30 rig with COP 3038
rock drills and one Rocket Boomer L2 C
Mine coordinate system
X/Y horizontal
Z vertical
Reference point
with the COP 1838, as well as the
Rocket Boomer 352S.
Mine navigation
The availability of orebodies at Garpen-
berg suitable for mining with longhole
production drill rigs led to a further
collaboration. Having already transferred
RCS technology to the Simba longhole
drill rigs, Atlas Copco provided
the mine with a Simba M7 C that is
additionally able to use new software
for precision longhole drilling. This
utilizes Garpenberg’s mine coordinate
reference, mapping and planning sy-
stem in a similar way to the software
developed for the Rocket Boomer L2 C
units.
Using a PC card, the Mine Navigation
package can effectively integrate the
Simba RCS with the mine co-ordinate
reference system, allowing the operator
to position the machine at the correct
vertical and horizontal coordinates in
the drilling drift for drilling planned
longhole fans in precisely the intended
place. Using the drill plan supplied by
Microsystem (or, in other mines, the Ore
Manager package) to the Rig Control
System, the operator can drill to the
exact x, y and z positions prescribed
garPenBerg, Sweden
for each hole bottom. Just as the Rocket
Boomers can use the MWD system
while face drilling, so the Simba can
use Quality Log to record drilling
parameters and compare the planned
and actual result, allowing holes to be
re-drilled if necessary.
This new technology will help Gar-
penberg to optimize economy and pro-
ductivity when applying long hole drilling
mining methods. The target for 2007
is to mine about 600,000 t of ore by cutand-fill,
300,000 t by sublevel stoping,
150,000 t by rill mining and 150,000 t
by crown pillar removal. Further ahead,
sublevel stoping may contribute 50%
of total mine production. However, at
present this mining method is completely
new to the mining teams at
Garpenberg, and they have just started
the process of getting acquainted with
long hole drilling methods.
acknowledgements
This article is based upon an original
report by Kyran Casteel. Atlas Copco
is grateful to the mine management at
Garpenberg for their assistance with
site visits, and in particular to Tom
Söderman and Lars Bergkvist for com-
ments and revision.
underground mining methods 51
X
(x, y, z) Y
Navigation system for downwards longhole production drilling.
Z
Reference line