GROUND SUPPORT
Minova's UniPass Bolting Technology is
described as an innovative ground support
system for one and two step rock bolting, which
combines Minova hollow bolts and self-drilling
anchors with its patented bulk injectable resin,
CarboThix
There has been a big move in the ground
support industry in recent years to offer
pumpable resin systems for underground
rock bolting, delivered via dedicated mechanised
bolting rigs. Orica-owned Minova told IM that it is
introducing its UniPass Bolting Technology –
described as an innovative ground support
system for one and two step rock bolting, which
combines Minova hollow bolts and self-drilling
anchors with its patented bulk injectable resin,
CarboThix. By combining these two products,
Minova says it has created “a unique rock bolting
solution that has been engineered to suit even
the most demanding requirements of hard rock
underground mining and tunnelling
environments.” The use of pumpable resin and
hollow bolts is quickly gaining traction in
underground operations due to the ease of use,
clean operating environment, improved safety,
and the ability to provide instant ground support,
enabling the miner to move faster.
Mines are extracting ores deeper than ever
before, resulting in higher rock stresses,
potential increase of convergence, dynamic
events, and rock bursts. There is an increased
demand on ground support applications, the
products used and the safety of operators.
Existing rock reinforcement solutions can be
prone to limited ductility, installation difficulties,
especially in broken ground and limitations on
the efficiency and productivity of installation
processes. Minova’s Peter Assinder, Global Head
of Sales, Marketing and Technology comments:
“Mining companies are looking to decrease such
risks and increase productivity by speeding up
the bolting cycle and introducing mechanisation
and further automation options. OEMs and their
contractors are also looking to enhance the
quality of materials used in mines to deliver
installation consistency.”
For the last eight years, Minova says it has
been developing a solution which it says provides
answers to the requirements for increased
automation, greater mine mechanisation,
improved productivity and moving miners away
from the working face. “Working with a major
OEM of mechanised bolting equipment, Minova
further developed their industry leading
pumpable resin CarboThix and self-drilling
hollow bolts to enable single pass installation of
ground support, which Minova has termed
UniPass.”
Safe,
deep
mining
Paul Moore looks at key developments including the use of
pumpable resin with bolts & SDAs for rock reinforcement
The OEM company that Minova worked with to
develop the UniPass system is Epiroc, with the
system designed to work with its Boltec M and
Boltec E models. Last year Peter Bray, Global
Product Manager, at Epiroc, had this to say: “An
important factor to achieve a workable rock
reinforcement solution is to have a system where
the bolt design, bonding agent and bolting rig all
work together to provide a robust and reliable
bolt installation. To this end, Epiroc has worked
hand in hand with a leading bolt and chemical
supplier to create a bolting system that
addressed the issues faced with long-term
bolting in poor ground conditions.” The result of
this work is an integrated pumpable twocomponent
resin system that can be used with a
Self-Drilling Anchor style bolt in tougher ground
conditions or, alternately, with a one-step or twostep
hollow bolt in both hard and moderate rock.
A major part of any new development process
involves extensive laboratory and mine site
testing. Minova was the material supplier for the
ground control work package of the EU funded
Horizon 2020 Sustainable Intelligent Mining
Systems (SIMS), a 3-year program from 2017 to
2020, to demonstrate new technologies for the
mining industry. Minova’s hollow bolt and
pumpable resin technology was extensively and
successfully tested on Epiroc Boltec machines at
LKAB’s Malmberget mine in northern Sweden as
part of the SIMS work.
Assinder comments: “The results surpassed
the benchmarks set by the work program in
terms of number of bolts installed per shift. The
work undertaken during SIMS further allowed
Minova to develop and fine tune the bolts and
resins and installation accuracy and consistency,
including optimum mixer units for the resin
across a range of operating environments and
approved greases to flush the bolting system
after each bolt installation.”
The company adds that it is important to note
that supporting materials and processes are
almost as important as the bolt and grout
materials, to ensure consistent quality of
installation. “Minova’s static mixers and greases
ensure that the two-component resin is mixed
and installed correctly for every bolt installation.
Additionally, an extensive testing program,
including on mine environmental monitoring and
laboratory testing provided extra confidence
concerning the structural and environmental
stability of the resin.”
A series of dynamic drop tests undertaken in
Europe and Canada further proved the
performance of the hollow bolts in dynamic
environments for a number of bolt and resin
configurations, thus providing confidence to the
mine customers that Minova’s new technology is
appropriate for their operations. Minova’s
portfolio comprises Static, Yielding and Dynamic
Hollow Bolts and three main CarboThix resins
(Standard, Fast and Rapid) to provide an all-inone
bolting system that has been engineered to
suit the most demanding requirements of
underground mining and tunnelling environments.
The products offered are designed to improve
installation times and to address hole collapses
when used in fractured ground. It is a flexible
system that features a load-bearing hollow bolt
that is encapsulated by a resin grout body. All
bolts are available with or without welded
sacrificial drill bits to allow for both one step and
two step bolting processes. The welded on drill
bit has been specifically designed and
manufactured to allow a reduced borehole
annulus, lower resin consumption, improved load
transfer, shortened drilling time and guaranteed
performance (no bits breaking or spinning-off
during installation) whilst providing additional
anchorage capacity.
Minova manufactures a wide range of grout
solutions for rock bolting applications. UniPass
bolting technology introduces CarboThix, its
46 International Mining | JULY/AUGUST 2020