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