EXPLOSIVES AND BLASTING
payback period – is costing the industry millions
of dollars of sustaining capital.
Dyno Nobel Vice President, Product and
Applications Technology, David Gribble, explains:
“There are some applications where you carry out
this development and you come back a few years
later and look to either rehabilitate or create new
drives off of it.”
In underground mines with challenging ground
conditions where the initial drilling and blasting
practices may have been lacklustre, this re-entry
can create safety concerns.
“Companies are trying to mitigate any safety
issues by working to remove people through
automation and technologies such as wireless
initiation – which is great – but we are of the
opinion that part of the reason for these
technologies is that the drives were damaged in
the first place,” Gribble told IM. “If we can create
competent drives with minimal damage from the
off, then a lot of the issues that happen down the
track – which we’re trying to mitigate against –
should go away.”
This is where Dyno Nobel’s EZshot ® electronic
detonator comes in.
Offering users the benefits of accurate
electronic timing without the complications that
come with wired systems, it has been designed
with underground perimeter blasting in mind.
EZshot uses shock tube for signal transmission
and has factory-programmed delay times ranging
from 1,000 to 20,000 milliseconds, with longperiod
delay timing ideal for underground
perimeter blasting, according to the company. This
is helped by the electronic initiation unit inside the
detonator, which eliminates scatter – an inherent
property of traditional pyrotechnic systems – to
ensure firing occurs at the pre-designated delay
time.
These design elements all help confront the
issue of overbreak in perimeter blasting, according
to Klaric.
“A good measure of well controlled, smooth
blasting is when you see ‘half barrels’ left behind,
which are remnants of the holes that were blasted
in the rock mass,” Klaric told IM. This is
sometimes witnessed in competent,
homogeneous rock masses, but rarely spotted in
poor, challenging ground where there is faulting,
jointing or discontinuities.
“In such ground, there is greater potential for
overbreak and damage after perimeter blasting.”
Klaric explained: “Your profile might come out
as designed, but there could be more damage
beyond the perimeter. As you go to install your
ground support, there is potentially an area of the
drive where the ground support is going to prove
ineffective.”
It is these challenging rock conditions where
EZshot could provide the most value to miners,
according to the company.
MAXAM is bringing its X-Energy application to the blasting sector to provide measurable total cost of
ownership (TCO) benefits to the mining industry. From rock characterisation to an optimised blasting
operation with a measurable downstream impact, X-Energy allows miners to maximise the use of
energy through a mix of the “most advanced explosives” technology in the market (Smart RIOFLEX)
and digital tools for optimised blast design and execution, integrated in the MAXAM Blast Center,
MAXAM says.
“Recently started in the operations of selected customers, and thanks to its tailor-made, modular
nature, X-Energy can provide a customised solution for each operation,” Vicente Huélamo, MAXAM
Chief Technology Officer, explains.
MAXAM’s Smart RIOFLEX technology can instantaneously adjust explosive density to match a wide
range of rock mass conditions, with one single matrix and sensitising unit, according to the company.
Its “mechanical sensitisation” provides more control than chemical gassing, ensuring the exact
product quantity at the right stemming length as well as operational time savings, MAXAM claims.
MAXAM Blast Center, meanwhile, is a cloud-based platform enabling the full digitalisation of
blasting services.
The company explains: “It integrates a full range of MAXAM digital tools to design, plan and
conduct the most efficient drilling and blasting operation, enabling selective energy application as
per rock characteristics. MAXAM Blast Center is envisioned to include third-party data for
downstream impact tracking and optimisation.”
Other modules of the X-Energy application include RIOBLAST – an advanced, user-friendly updated
blast design and simulation suite now integrating data from measurement-while-drilling tools; FMS
(Fleet Management System) to plan, control and optimise MSU (loading units) operations; FDL (field
data logger) to verify, correct and record data on the bench; and RIOTRONIC X+, an electronic
initiation system and detonator to produce a broad range of precisely timed blasts.
Huélamo added: “MAXAM’s X-Energy application services unlock potential benefits by allowing the
selective application of the explosive energy according to the rock properties, resulting in clear
sustainable savings for our customers.”
The X-Energy application permits a mine to customise the design and execution of each individual
blast and integrate it into the requirements of downstream operations.
The benefits in enhanced safety, reduced impact to the environment, optimised rock
fragmentation, efficient use of energy, higher production, and reduced costs are helping mines
become more competitive and sustainable, the company says.
In trials at an underground mine where variable
ground conditions and temperatures were
observed, a 12% overall reduction (from 22% to
10%) in overbreak was observed with a switch
from NONEL LP to EZshot detonators, according to
Dyno Nobel.
Operators witnessed visible half barrels in poor
ground where they had never seen them and full
profile half barrels in good ground during these
trials, the company reported.
The benefits did not end there.
There was a measurable reduction in the
volume of material scaled off the walls after using
EZShot – thanks to the improved blasting profile –
and initial calculations indicated a positive $/m
benefit to development mining costs, according to
the company.
“If you are starting to improve and get
consistency in your blasting and the drives you are
delivering, you can start to consider adapting your
rock support measures,” Klaric said.
For example, removing six or seven roof bolts
per heading due to the improved blasting profile
could see costs drop by A$3,000-4,000 ($2,085-
2,780) per heading, he explained.
These benefits are applicable in all forms of
mine development, but it is long-life operations
set to reap the most rewards from a switch to
EZshot.
“This could be your block cave, or panel cave
type of operations where some of those drives
might be in place for 30-50 years,” Klaric said. “If
you get development right in these applications,
everything else will be right down the line.”
Pain points
Enaex is developing an electronic initiation
solution of its own for the underground
development sector, but it is also addressing other
customer pain points below ground, exemplified
by the work it is carrying out at two major block
cave operations in Chile.
Safety in block caving – particularly in undercut
levels – while guaranteeing productivity during
production blasts is a major area of focus for the
company.
“To address this challenge, we developed
Ubex ® One, an explosive loading truck with a teleoperated
arm able to load holes from a safe
distance up to 10 m away,” Bachelet said.
“Associated with our range of underground
emulsions, you can increase the productivity by
almost 20%, reaching close to 95% of the targeted
volume of rock to be blasted.”
20 International Mining | JULY/AUGUST 2020