AROUND THE
INDUSTRY
38
MODERN QUARRYING
October - November 2013
EQUIPMENT,
P DUC S & SERVICES
The Megapump range of double-salt
emulsions from BME is so stable that it
can be pumped and re-pumped mul-
tiple times, opening the door to a variety
of cost-saving opportunities for under-
ground mines.
“We can confidently say that our
emulsion is the most stable on the SA
market,” says Selwyn Pearton, research
and development manager at BME, “con-
taining an ammonium nitrate and calcium
nitrate mix that delivers remarkable quali-
ties, compared to other double-salt emul-
sions on the market.”
In addition to its resilience to mul-
tiple pumping cycles, it also has a very
long shelf-life, having been successfully
used for blasting up to a year after being
manufactured. “The ability to re-pump
the product has huge benefits for an
underground operation,” he confirms.
“Essentially, it allows a mine to pump
emulsion from the surface to the under-
ground workings safely, quickly and
cheaply, avoiding much of the disrup-
tion and expense associated with normal
explosives.”
For a start, the emulsion is regarded
as a 5,1 oxidiser in terms of the United
Nations transport classifications, allowing
it to be transported without the stringent
requirements applied to other explosives.
It is only sensitised in-situ in the blasthole
WearCheck heads into East Africa
Condition monitoring specialist WearCheck recently extended its growing African footprint
from Southern Africa to West and now East, into Tete Province Mozambique, where it ser-
vices the region’s burgeoning precious stone and coal mining industries. This follows hard
on the heels of the recent launch of the company’s first West African laboratory, in Ghana.
WearCheck Mozambique offers a range of condition monitoring services, including oil
analysis, coolant testing and 24-hour sample turnaround time.
Managing director Neil Robinson
explains: “The concept of analysing oil sam-
ples from a machine or component is similar
to that of taking a blood sample from a per-
son – the results determine the health sta-
tus of the unit. WearCheck’s highly-skilled
diagnostic team then analyses the results
and recommends how to rectify any abnor-
mal findings.”
The Tete laboratory –WearCheck’s tenth
– joins an expansive network that is strate-
gically positioned to support large industry
clusters such as earthmoving, industrial,
transport, shipping, aircraft and electrical
operations.
Re-pumpable emulsion stability cuts costs
at the workface, when the blast is about
to take place. This means that the usual
safety precautions and time constraints
associated with moving explosives under-
ground including dedicated shaft and
locomotive cycles can be avoided. There
are also considerable savings in labour as
emulsion can be pumped between cas-
settes and through the shaft system sim-
plifying the transportation cycle on the
way to the blastface.
BME has also engineered a bag or
cassette-based charging system through
which workers can transport emulsion
through the demanding confines of nar-
row-stope mines, before being loaded
into blastholes quickly and efficiently.
While it is much safer and simpler to
transport any emulsion rather than an
explosive, the limitation of less stable
emulsions is that they can’t stand up to
the number of pumping cycles ideally
required to get it from a surface location
to the stopes.
In a typical chain of events, the emul-
sion is first pumped into the silo at the
manufacturing facility before being
gravity-fed into the tankers that supply
the mine. At the mine the emulsion is
pumped into a silo before being pumped
through multiple transfer cassettes or
pipelines before entering the charging
unit that will again pump the emulsion
into the blastholes to charge them.
Applications vary between mecha-
nised operations where the excavation is
large enough for a mechanised charging
unit, and a narrow reef environment that
requires workers to take the emulsion into
the stope for blasting. The latter can take
advantage of BME’s closed emulsion sys-
tem, where the product is pumped into
small, sealed bags which are cycled into
the confined spaces where blasting takes
place before being returned for refilling.
The design of the system ensures that
there is no contamination of the emul-
sion, which could damage equipment
and affect the results of the blast.
“It is a significant drawback to alter-
native systems that they cannot pump
emulsion into small bags due to the risk of
crystallisation – caused by a breakdown
of the emulsion matrix,” says Pearton.
“Most other emulsions on the SA market
can only be re-pumped about three times
before they start to breakdown.”
The stability of the BME product also
allows it to stand for a very long time –
both before and after it is sensitised – and
still deliver the high detonation quali-
ties for which emulsions are well known.
“The longest that we’ve had our emulsion
stand is a whole year,” he says. “The mine
actually closed for a period, and then
re-opened and continued to mine with
the product that we had initially sup-
plied a full year earlier. That is unheard
of in SA, and it’s only possible because of
Megapump’s remarkable stability.”
Once the product has been charged
into the blast-face, it has also demon-
strated its longevity. An opencast client,
for instance, had blastholes charged six
months before they were finally deto-
nated, with no detrimental impacts on
the quality of the blast.
Operator filling an underground charge unit
with Megapump emulsions.
Gabriel Perengue pictured in the new Tete lab.
