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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During pilot hole drilling <strong>and</strong> rea-<br />
ming, the rubber sealed muck collector<br />
is applied adjacent to the rock face. The<br />
muck slides on a chute assembly to the<br />
rear of the machine.<br />
The two earlier Robbins 34RH ma-<br />
chines featured a 270 degree working<br />
range, with muck spilling to either side<br />
or to the rear end of the machine, whereas<br />
the muck chute on the new El Teniente<br />
34RH machine has a working range of<br />
90 degrees, due to simpler <strong>and</strong> more<br />
compact design.<br />
The Robbins 34RH features a remote<br />
controlled hydraulically operated slide-<br />
opening worktable for use in both down-<br />
reaming <strong>and</strong> boxhole boring applica-<br />
tions. The entire drill string, including<br />
boxhole stabilizers <strong>and</strong> reamer, can pass<br />
through the worktable of the machine.<br />
The st<strong>and</strong>ard frame Robbins 34RH<br />
currently in use at El Teniente accommodates<br />
a 692 mm-diameter reamer<br />
through the worktable, while a wide<br />
frame model of the 34RH accommodates<br />
a 1,060 mm-diameter reamer.<br />
The Robbins 34RH worktable is<br />
equipped with semi-mechanized wren-<br />
ching, which features a hydraulically<br />
powered forkshaped wrench mani-<br />
pulated from the operator’s control<br />
console.<br />
The rod h<strong>and</strong>ler is designed to pick<br />
up all drill string components, including<br />
boxhole stabilizers <strong>and</strong> reamer.<br />
robbins 53rH<br />
The Robbins 53RH is a low profile,<br />
medium-diameter raise drill, suitable<br />
for boring orepasses <strong>and</strong> ventilation<br />
shafts. It is a versatile multi-purpose<br />
machine, capable of boring upwards<br />
boxhole, downreaming, or conventio-<br />
nal raise boring, without modification<br />
to the drive assembly.<br />
It has a hydraulic drive to enable<br />
variable rotation speeds <strong>and</strong> has dual<br />
drive motors placed offline on a gathering<br />
gearbox that transmits torque to the<br />
drive heads.<br />
The Robbins 53RH features a raise-<br />
boring <strong>and</strong> a boxhole float box, which<br />
allows the boring methods to be changed<br />
by simply installing drill rods in<br />
either the upper or lower float box. In<br />
addition, this multi-purpose unit is provided<br />
with a removable water swivel, to<br />
Robbins 53RH set up underground.<br />
facilitate pilot bit flushing in both raise<br />
boring <strong>and</strong> boxhole boring modes.<br />
The El Teniente machine has been<br />
substantially upgraded from previous<br />
versions of the Robbins 53RH, to in-<br />
crease its productivity <strong>and</strong> working<br />
range. The input power has been increa-<br />
sed by 31% to 225 kW, the torque has<br />
been increased by 44% to 156 kNm,<br />
<strong>and</strong> the thrust by 21% to 3,350 kN.<br />
To achieve the same low profile as<br />
st<strong>and</strong>ard Robbins 53RH machines, high<br />
thrust telescopic cylinders have been<br />
used. This has resulted in a machine<br />
with an overall height of just 2.9 m that<br />
utilizes 750 mm-long drill rods with an<br />
outer diameter of 286 mm.<br />
For ease of operation, the unit is<br />
equipped with semi-mechanized wren-<br />
ching in the worktable, as well as the<br />
headframe. This features a hydraulically<br />
powered forkshaped wrench ma-<br />
nipulated from the operator’s control<br />
console.<br />
The larger Robbins 53RH does not<br />
feature an opening worktable, as the<br />
wings of the stabilizers <strong>and</strong> the reamer<br />
are attached on top of the machine.<br />
Muck is h<strong>and</strong>led by a separate col-<br />
lector system designed to suit the ma-<br />
chine. Unlike the Robbins 34RH, this<br />
muck collector is not integrated into<br />
the machine design, but is attached to<br />
the rock face by means of rock bolts.<br />
As it is separated from the derrick<br />
BOxHOle BOring aT el TenienTe<br />
assembly, this remote controlled, hydraulically<br />
operated system provides a<br />
360 degree working range for channelling<br />
the muck away from the machine.<br />
The remote controlled rod h<strong>and</strong>ling<br />
system on the Robbins 53RH is used for<br />
side <strong>and</strong> ground loading of drill pipes.<br />
This configuration of pipeloader has<br />
previously been used on all other<br />
Robbins models, <strong>and</strong> is now available<br />
on the 53RH. Due to the restricted ma-<br />
chine dimensions, it is not possible to<br />
add the stabilizers within the machine<br />
frame. Instead, the pipeloader inserts<br />
a stabilizer pipe with stabilizer wing<br />
attachment sleeves.<br />
Once this is pushed through the<br />
headframe, the lightweight stabilizer<br />
wings are attached to the sleeves be-<br />
fore continuing on through the muck<br />
collector, <strong>and</strong> into the hole.<br />
A new reamer h<strong>and</strong>ling system has<br />
been integrated into this machine design<br />
to eliminate the h<strong>and</strong>ling of the<br />
reamer at each set up. The reamer has<br />
been designed to bolt on top of the head-<br />
frame during transport <strong>and</strong> erection.<br />
The hollow centre design of the reamer<br />
still allows prepiloting of the hole if de-<br />
sired, in which case a special stinger<br />
is inserted through the headframe <strong>and</strong><br />
into the reamer, whereas the reamer is<br />
unbolted from the machine frame <strong>and</strong><br />
attached to the stinger. The diesel transporter<br />
used for this machine is sized to<br />
underground mining methods 93