TECHNOLOGY
U
“Jobseekers are often
not aware of what it
means to settle near
an active blasting site/
working quarry, and
over time, the drill and
blast activities become
a nuisance.”
se of explosives is not going
to disappear any time soon,
as they remain the cheapest
method of breaking up
ground. The work of Simon Tose, AEL
Mining Services (AEL) consulting
mining engineer, bridges the gap between
explosives and mining engineering. He
looks at explosives from the chemical point
of view and how to apply them practically
in the field. He explains that a quarry is
an economic hub and attracts people and
businesses for land and economic activity,
which in turn require social amenities.
“Over time, these people tend to forget
that the quarry was the original economic
hub and magnet for investment and
employment. Those jobseekers are often
not aware of what it means to settle near
an active blasting site/working quarry,
and over time, the drill and blast activities
become a nuisance.”
Dust is another product of quarry and
activities and will remain important when
considering blast designs and execution.
“Local regulatory standards are often
not stringent enough to accommodate
residential areas encroaching the site
and therefore the industry needs to look
globally and adopt best practices and more
stringent controls,” says Tose.
“International pressure is forcing
change in this regard: there are only
about seven or eight explosives suppliers
— including Orica Explosives, Dyno
Nobel, Solar Group, BME, and AEL — all
of which are international companies,
meaning international standards will
become the norm by default. For instance,
AEL has expanded out of South Africa,
into Africa and Australia. We find the
standard applicable here in South Africa
is not acceptable in Australia, so as an
international group we have to upgrade
our standards to have the ability to operate
in Australia. Once upgraded, it isn’t
practical to implement different standards
in different countries and those standards
become the norm here in South Africa,”
Tose adds.
Going wireless to win customers
Blasting has evolved to the point of using
electronics with a wire, but the future of
blasting is wireless — taking safety to a
higher level through automation — and
Tose says AEL already has some working
units being tested. Each detonator would
talk to the detonators around it, and the
emulsion is transported to the mine and
only manufactured remotely into explosive
form once in the hole on the bench. This
changes the outlook of transportation —
you are no longer transporting explosives
but chemicals and the truck itself can
be automated.
Tose describes a number of alternatives
to blasting. One is self-tamping gas
cartridges with some form of a liquid or
solid chemical that, when you initiate,
turns the liquid or solid to gas. “This is
a more expensive alternative, but has
the advantage that it only requires a
clearance area of approximately 70m to
80m compared to the traditional 500m to
600m needed for explosives,” says Tose. “If
quarry operators want to run the operation
for life-of-mine, then this is something
they are going to have to think about.
Right now, it would price you out of the
market, but at some point, the pricing of
this alternative will come down while the
environmental issues will make it a
viable alternative.”
Other alternatives to drilling are
using shearers and rock cutters. These are
expensive and at present not viable for
most South African quarrying operations.
These are not new technology but have
long been used in cutting out soft coal,
and also harder rock as the technology
advances.
Tose explains that this level of
automation means the drilling crew can
be removed, and the drive is now to also
remove the explosives crew — for
safety reasons.
The view from Australia
While automated construction and mining
is in its infancy within South Africa, Tose
describes what is possible by referring
to some operations in Australia where,
“Load and haul trucks are ‘driverless’ and
remotely operated by a joystick; blast
holes are drilled without directly involving
manpower, while electronic blasting
systems, such as the AEL Intellishot™
system, enables remote firing capability,
removing the blaster from the blast vicinity
at blast time. Effectively, it talks to you and
you talk back to it. Only when you’re ready
to blast do you take it to a level where it’s
explosive — when you’re working with it
on a bench it’s intrinsically safe. What an
electronic detonator does for you is deliver
QUARRY SA | SEPTEMBER/OCTOBER 2018 _ 19