CANADIAN TECHNOLOGY
dispatching is more efficient; safety
accountability time during an emergency is
reduced. Data from work habits can be stored
and reviewed.
Another application is the optimisation of
ramps by prioritising use depending on
equipment.
“Newly developed tags are being introduced
every day,” Brunet says, “these only add to the
breadth where a passive RFID system can be
beneficial. Tags can now be embedded in steel or
hammered onto a skid, they can be carried by
personnel without being intrusive, or they can be
installed on vehicles.”
Greener processing
Back to #DisruptMining and another semi-
finalist, Dundee Sustainable Technologies (DST)
which last December announced successful
extraction results on gold concentrates from
Chile using its proprietary chlorination
technology at its demonstration plant in Quebec.
A gold extraction yield of 97.3% was achieved at
the outlet of the chlorination reactor with full
environmental controls over the sulphur and
mercury content.
“These results are another important
demonstration of the efficiency and effectiveness
of the DST chlorination process and of its
potential as a robust and environmentally
friendly alternative to cyanide extraction in the
gold mining industry,” said Brian Howlett,
President and CEO of DST. “We are partnering
with a number of mining companies in an effort
to advance our technology and further explore
the commercialisation of our patented process.”
In September 2015, DST entered into an
agreement with a Chilean mining company for
the processing of gold concentrate at the pilot
scale using the chlorination process. Excellent
results at the pilot scale enabled DST to move
forward to the next stage, which involved the
processing of the concentrate which contained an
estimated 110 g/t Au, Cu grades of 9.0% and
mercury content in excess of 700 g/t at the
demonstration plant.
DST processed 40 t of this complex material
which is difficult to process using conventional
processing methods without the associated
environmental liabilities and metallurgical
challenges. In particular, the 700 g/t of mercury
was effectively removed during processing to a
level of 99%.
Through the development of patented,
proprietary processes, DST extracts precious and
base metals from ores, concentrates and tailings,
while stabilising contaminants such as arsenic,
which could not otherwise be extracted or
stabilised with conventional processes because
of metallurgical issues or environmental
considerations.
42 International Mining | APRIL 2017
At present, DST’s most advanced proprietary
process is associated with the extraction of
precious metals using a chlorination to provide a
cyanide-free alternative for the exploitation of
gold deposits. The primary benefits of this
innovative technology are shorter processing
times, a closed-loop operation eliminating the
need for costly tailings ponds, and reducing the
environmental footprint related to the inert and
stable cyanide-free tailings.
The chlorination process developed by DST is
a recognised ‘green technology’ for which it was
awarded a C$5 million grant by the Government
of Canada for the construction and operation of a
demonstration plant. The plant serves as a
demonstration platform for the chlorination
process on an industrial scale and under
continuous operating conditions. The corporation
has received, from Environment Canada, through
the Canadian Environmental Technology
Verification Program, an independent certification
of the performance of its cyanide-free gold
extraction process.
In addition to the chlorination process, DST
operates a pilot plant designed to demonstrate
its arsenic stabilisation process for the
sequestration of arsenic in a stable glass form.
This process involves a technique to segregate
arsenic and therefore provides opportunities to
process materials considered too toxic to be
exploited or stabilised using conventional mining
methods.
#DisruptMining semi-finalist Scanimetrics’
wireless monitor and sensor products are
packaged to survive extreme temperatures, harsh
weather, and demanding operating conditions.
The company can provide reliable data on the
condition of equipment to help optimise
maintenance programs and maximise equipment
uptime.
DisruptMining considered Scanimetrics’ WiTAP
and MoteScan technologies. The system
measures moisture, compaction and temperature
of ore deep inside the heap of a heap leach
operation and inputs this data into its MoteScan
cloud. The data is then analysed and made
available through a web application. Together,
these technologies will allow gold mining
companies to recover more gold from leach pads
in a more efficient manner. Monitoring below a
leach pile or pond to detect a leak through the
impermeable layer would lower compliance
costs.
Woodgrove Technologies’ Staged Flotation
Reactors (SFRs) are attracting worldwide interest,
providing major reductions in footprint, capital
investment, power and air, operating costs. SFRs
are uniquely designed to eliminate the pumping
requirements of the impeller. The power from the
impeller goes directly to particle collection.
Woodgrove explains the SFR “was developed
by going back to the first principles of flotation
and examining how best to optimise the various
phases of flotation without preconceived
constraints. The result is a machine that
optimises the three stages of flotation within
three separate zones – particle collection, phase
separation and froth-recovery – such that each
zone is mutually exclusive from the requirements
of the other zones. Froth drop back is minimal
and tightly controlled. The constrained froth
recovery zone allows for much better froth
loading and stability in a scavenger SFR,
resulting in better recovery and upgrading. The
very low air requirements combined with water
washing yields excellent selectivity.”
The company reports financial benefits of the
SFR as:
n Power consumption reduced by approximately
50%