WORLD PROSPECTS_visuals 23/08/2016 09:10 Page 1
WORLD PROSPECTS
Enaex Pirex performs in extremes
t is well known in the mining industry that it is
difficult to operate at high altitude for a number of
reasons. Enaex SA is the leading supplier of
integrated explosives solutions and blasting services
in Chile and in the wider Latin American market. A
high proportion of its customers’ mines are at high
altitude. An example is a customer site located at
more than 4,000 m above sea level with a steppe
altitude climate characterised by the ‘Altiplanic Winter’,
making for frequent thunderstorms, temperatures of 20°C and an average annual rainfall of 150 mm. The
mine produces copper cathodes, concentrate and
molybdenum from various geotechnical units,
including argillic, sedimentary, acidic, propylitic rocks
and different types of porphyry. One of the main
features of the massif is the manifestation of pyrite
present in the rock at the work site.
The mine worked with Enaex on the use of a
special blasting agent to delay any exothermic
reaction that could threaten the operational tempo if
there was a spontaneous premature detonation. In
addition, the Enaex explosives have accomplished
the proper fragmentation, optimising the powder
factor to meet the objectives of material removal
outlined in the client’s business plan. The Enaex
offering also has the ability of dosing low densities to
control the blasting power and limit any damage to
the pit walls.
Enaex says that by using its latest products, the
customer’s direct cost has been optimised positively,
because it has been able to increase the drilling rate,
so the same amount of material is removed with
fewer drilled holes, reducing the consumption of steel
raw materials, diesel oil and energy in this process. In
I
blasting terms, the project has again shown that even
when there is a decrease in the explosive load factor,
performance of the detonation pressure in reactive
rocks can still achieve more with less consumption. A
saving of around $5 million per year has been
estimated at the site.
Using Enaex Pirex®, a new special product for
reactive rocks, “and a professional and experienced
Technical Assistance team under extreme operating
conditions, we were
able to increase
blasting
effectiveness going
from 150 to 250 drill
holes loaded
simultaneously
every day. Also we
were able to
decrease, working
closely with the
plant, the blasted
particle size from
65% <2 in to 72.5%
<2 in for drilling
diameters of 12¼
in.”
After many years
of working with
another supplier, it
was necessary for the mine optimise the drill
patterns, extending them 1 m into the burden area.
“We have seen at least a reduction of 5% in the costs
of drill and blast, and considerably enhanced shovel
performance”, says a mine site coordinator. The
Enaex initiatives have achieved an increase of 8% of
the drilling rate and reduced the load factor by 11%.
Enaex says these results from operations at high
altitude show “highly versatile products in extreme
operations, timely and effective technical assistance
to optimise the costs of the mining process,
monitoring proficiency and an corresponding impact
on outcomes, and optimisation of operational
processes for overall productivity.”
Enaex headquarters are located in Chile and the
company also currently works elsewhere in Latin
America with operations in Argentina, Peru, Colombia
and Brazil (through Britanite). In 2015, the prestigious
French initiation systems company Davey Bickford
joined the group, enabling it to deliver new technology
to customers and expanding its portfolio of products
and services to the market. www.enaex.com
Tackling nitrate contamination of water in mines
I
4 International Mining | SEPTEMBER 2016
emulsion released only about 0.7% of its nitrate
content. “The key factor here is the
effectiveness with which the oil in the emulsion
– the fuel phase of the mixture – surrounds and
isolates the small droplets of saturated oxidiser
salt, preventing them from dissolving in water,”
said Alberts. “On the other hand, our tests
confirmed that ANFO dissolves completely
when it comes into contact with water.”
High levels of wastage of ANFO – the mining
sector typically accepts that about 30% of
ANFO delivered to a blast site is not consumed
in blasting – suggest that it may be a
contributor to nitrate levels in water pass ing
through mine workings.
Another advantage of emulsions highlighted
by the tests was that no oil was released,
ensuring that water contamination by oil is also
prevented; both the nitrate and the fuel phases of
the mixture are bonded tightly by the emulsifier.
“BME emulsions have already contributed to
environmental sustainability on mines by
incorporating and consuming previously used
oil in its emulsion products, helping mines to
dispose of these liquids safely and costeffectively,” he said. “The way we have evolved
As the pioneer in cold emulsion explosives in
South Africa BME has evolved this technology to
new levels
the matrix also ensures that no oil is released
when our emulsion comes into contact with
water at the stope face.”
As mines work to prevent or mitigate
s
n South Africa’s increasingly water-scarce
and environmentally regulated mining
industry, BME says its emulsion explosives
help keep nitrates out of mine water –
preventing possible groundwater contamination
and allowing optimal recycling of water on site.
“Recent international studies suggest that up
to 28% of nitrates from traditional ANFO
explosive can leach into water draining through
underground mine workings during a blasting
campaign,” said BME Operations Manager Neil
Alberts. “These levels can be reduced to as
little as 2% by applying best practice, but the
long-term solution lies in explosives that do not
release nitrates into water sources.”
As the pioneer in cold emulsion explosives in
South Africa, BME has evolved this
technology to new levels over the past three
decades, said Alberts. “Among the
characteristics of our emulsions range is its
excellent water resistance, which means that
the explosive material does not dissolve readily
in water,” he said. “This reduces the amount of
nitrate leaching to negligible levels.”
Tests conducted by BME indicated that, after
being immersed in water for a month, its