Mining_Methods_UnderGround_Mining - Mining and Blasting

MeCHanized BOlTing
impact power from a COP 1025 hammer,
is used for installing split-set bolts.
The complete rock reinforcement job is
finished in just a few minutes.
Boltec MC flexibility
The Boltec MC delivered to the Creighton
mine is capable of handling several ty-
pes of bolts: split-set, mechanical anchors,
resin grouted rebar and Swellex.
The switch of accessories between different
bolt types takes 5-10 minutes. To
minimize water demand during drilling,
water mist flushing is used. The
Boltec MC can also be equipped with a
portable operator’s panel connected by
a 50 m-long cable.
Cartridge shooting is remote controlled
for the Boltec MC, and up to
80 cartridges can be injected before
refilling is needed. A unique feature is
the possibility to use two different types
of cartridges, with fast or slower curing
times, housed separately in the dual
cartridge magazine. The operator can
select how many cartridges of each type
to inject into any hole. For instance, he
can inject two fast curing cartridges for
the bottom of the hole, and follow up
with slower-curing cartridges for the
rest of the hole, all without leaving his
operator’s panel!
Cabletec lC for cable
bolting
Atlas Copco has developed a fully mech-
anized rig for drilling and cable bolting
by a single operator. The first unit
went into operation some years ago at
Outokumpu’s Kemi chromite mine
in northern Finland, and a second unit
went to Chile. Today, a significant number
of units are sold to many mines
around the world. The Cabletec LC is
based on the long hole production drilling
rig Simba M7, with a second boom
for grouting and cable insertion.
The booms have an exceptionally
long reach and can drill a line of up to
4.7 m of parallel holes from the same
rig setup. Likewise, the booms can reach
up to 8 m roof height, allowing the
Cabletec LC to install up to 25 m-long
cable bolt holes in underground mining
applications such as cut and fill mining
and sub level stoping. Furthermore, the
Cabletec drilling and installing cablebolts upwards, and Simba drilling blast holes downwards at Kemi mine.
drill unit can rotate 360 degrees and
tilt 10 and 90 degrees, backwards and
forwards respectively. The new rig is
designed on proven components and
technology featuring two booms - one
for drilling and the other for grouting
and cable insertion. It also features an
on-board automatic cement system with
WCR (Water Cement Ratio) control.
All these features facilitate a true single
operator control of the entire drilling
and bolting process. The two-boom con-
cept has drastically reduced the entire
drilling and bolting cycle time and, by
separating the drilling and bolting func-
tions, the risk of cement contaminating
the rig is eliminated. The operator
is able to pay full attention to grouting
and cable insertion, while drilling of the
next hole after collaring is performed
automatically, including pulling the rods
out of the hole.
Cabletec is equipped with the well
proven COP 1838 ME hydraulic rock
drill using reduced impact pressure with
R32 drill string system for 51 mm hole
diameter or R35 for 54 mm holes. Alter-
natively, the COP 1638 rock drill can be
used for soft rock conditions. Maximum
Cabletec main technical data
Length: 13.9 m
Width: 2.7 m
Height: 3.3 m
Turning radius: 4.3m / 7.5 m
Cabletec
Simba
hole length is 32 m using 6 ft rods and
RHS. The cable cassette has a capacity
of 1,700 kg and is readily refilled thanks
to the fold-out cassette arm. The cement
mixing system is automated, comprising
a cement silo containing 1,200 kg of dry
cement. The cement is mixed accor-
ding to a pre-programmed formula, re-
sulting in a unique quality assurance
of the grouting process. The cement
silo capacity is adaptable for up to 25
m-long, 51 mm-diameter holes.
To date, most holes have been drilled
in the 6-11 m range, for which the rig
has grouted and installed cable at a rate
of more than 40 m/h. Depending on type
of geology and hole diameter chosen,
the drilling capacity can vary between
30 and 60 m/h.
Conclusion
Rock support, including scaling, bolting,
screening, and cable bolting, is still
the bottleneck in the working cycle in
underground mining and tunnelling
applications. Clearly, any reduction in
the time required to install the necessary
support has a direct impact on the
overall cycle time, and consequently the
overall productivity and efficiency of
the operations. The fully mechanized
bolting rig of today, incorporating all of
the benefits of modern computer technology,
constitutes a major leap towards
improved productivity, safety and operator
environment.
Hans Fernberg and Patrik ericsson
32 underground mining methods