EXPLOSIVES AND BLASTING
Safety benefits surfacing
The success of WebGen in underground mining
has led to an increased adoption of the
technology in surface mining, according to Orica,
with the company having completed successful
surface blasts using the wireless system around
the world.
Its fully wireless capability presents an
opportunity to overcome one of the industry’s
most persistent limitations – a physical or wired
connection to each primer in a blast, Mooney
says.
“Wired systems have a large physical presence
and are susceptible to damage at every point
Hexagon’s holistic approach to drill and blast incorporates solutions to improve yield, fragmentation
and dilution.
Incorporating technology ranging from blast design and high-precision drilling to post-blast
analysis and optimisation, the approach empowers mines to take back the purchasing power on their
bulk commodity explosives, according to the company.
“A well-designed blast pattern and the effective execution of the blast plan using high-precision
drills are an important part of an effective drill and blast operation,” the company said.
Hexagon’s MinePlan portfolio features HxGN MinePlan Blast, a comprehensive software utility for
drill and blast reconciliation.
“Rather than risking high-wall stability problems, uneven blasting, poor fragmentation,
unnecessarily high energy costs, and dangerous working conditions, MinePlan Blast incorporates
charge and blast design templates that are based on sound engineering principles and methods
proven in mines worldwide,” the company said.
The MineOperate portfolio, meanwhile, features machine guidance for drills (as well as dozers and
loading equipment), with the OP Pro HP solution ensuring drilling is performed to the right position
and elevation.
“It provides accuracy and instantaneous feedback, meaning improved loading times across the
fleet, less mis-routed material, fewer hours of rework on ramps, roads, and benches, and fewer over-
and under-drilled holes,” the company said. “It is proven to improve both the quality of material
produced and fragmentation with precise drill hole placement and depth.”
OP Pro HP integrates with Hexagon’s operational management hub, MineEnterprise, for a single
source of reporting and support, the company says.
Then there is fragmentation data to consider.
Here, Blast Movement Technology (BMT) is an integral part of Hexagon’s drill and blast solutions,
providing accurate ore location information for open-pit mines. BMT, via sensors and software,
provides blast information used to recover a mine’s resources. It ensures that, post-blast, the mine
retains a full vision of where its orebody moved to.
Hexagon’s Split Engineering systems are used to automatically monitor different areas and
processes along the operation, such as in shovels, excavators, loaders, haul trucks, crushers,
conveyor belts, mill feed and screen decks, providing a unified approach to fragmentation
management, Hexagon says.
Monitoring trends in size at each point in the comminution circuit enables operational adjustments
in real time, while alarms can be created for oversize events, reducing the downtime from
inefficiencies caused by blockages and broken screen decks.
HxGN MinePlan Blast is a
comprehensive software utility for
drill and blast reconciliation,
Hexagon says
along the connecting line,” he explained. “The
potential for misfires due to downline damage has
commonly led to the application of redundant
initiation systems and can impede the loading of
adjacent blast patterns due to flyrock damage.”
Like other surface wireless systems, WebGen
for surface, removes priming, loading, stemming
and tie-in activities, in addition to reducing the
time employees spend on the bench.
With increased flexibility in pit planning and
blasted inventory, mine operations enabled by
WebGen can also prime and load larger single
blasts as well as eliminate firing window
variability, according to Mooney.
The lack of wires can also eradicate potential
hazards caused by weather events.
“Due to the conductive characteristics of wires,
lightning storms pose one of the primary
challenges in surface mining around the world,”
Mooney said.
Typically, in the event of approaching lightning
storms, a mining exclusion zone is placed around
the loaded blast or, in some cases, the blast is cut
short and immediately fired.
This does not happen with WebGen blasts.
“As WebGen does not require downlines and
surface wires, lightning production costs and the
risk of unplanned initiation of loaded blast holes
can be eliminated, while production constraints
from exclusion zones are completely removed.”
At a depth of 3 m below the collar of a blast
hole, WebGen units are protected from the
hazards of lightning, according to Mooney.
“The absence of lead wires in this scenario
prevents current transfer,” he said. “Additionally,
the magnetic field induced by lightning is not able
to activate a WebGen unit to fire.”
Mooney is confident some of these
characteristics will lead to new, WebGen-enabled
blasting techniques surfacing.
“For example, with WebGen, it is now possible
to allow traffic to safely flow over a loaded blast in
surface operations, providing full flexibility in pit
access and availability as well as significantly
improving vertical advance and efficiency across
the load and haul cycle,” Mooney said.
“This can dramatically optimise sequencing in
surface coal strip mining and drop cuts in surface
metal mining.”
Another example of “surface mining reimagined
with WebGen” is multi-stratum blasting, Mooney
says.
“This method involves drilling and loading
multiple benches in a single pass, providing
stemming decks in between the loaded benches,” he
said. “A single deck is fired and dug before firing
the next deck, reducing cycle times and bench
preparation costs, while increasing the overall rate
of vertical advance, fleet utilisation and safety
associated with operating around highwalls.” IM
24 International Mining | JULY/AUGUST 2020