ORE SORTING
no direct detection, then a proxy is often used,”
Beal said, explaining this is exactly the case for
NextOre’s MRA gold detection process.
Regardless of which technology is chosen over
the other, what is undisputable is the fact that
these sensors all work better at the front end of
the process flowsheet where ore is more
heterogeneous.
Auranen concluded: “We have conducted
several studies analysing the ore distribution –
typically after primary crushing. Why after primary
crushing? That is where the ore and waste can still
be effectively separated. When the material goes
to an intermediate stockpile and to further
crushing and grinding, it gets homogenised.”
New developments
The industry might still be in the process of
assessing how it can best use the current crop of
ore sorting technology on the market, but those
companies leading this change are already
preparing to launch new solutions to widen their
sensing and sorting scope.
NextOre, which has an MR analyser currently
installed on a 4,000 t/h conveyor at Newcrest
Mining’s Cadia East block cave copper-gold mine
in Australia and has two units ready for shipment
to Southeast Asia copper operations, has plans to
expand its mineral analysis capabilities through
the addition of new sensors, Beal said.
He explained: “The tendency for finer particles
within a copper sulphide orebody – in particular,
porphyries – to carry a disproportionate amount of
the metal within the orebody means that if you
can simultaneously track the particle size of what
is going across the belt and its precise grade, then
you can start making decisions based on these
two characteristics (particle size and grade).”
He said that the company has already
incorporated such a design into its new generation
of process flow diagrams for bulk sorting.
Beal added: “You could get to the point where
there is almost this designer mill feed and the
metallurgist in charge of the plant on any specific
day could plan for what is going to be fed through,
making sure the variation coming in is eliminated
before it goes into the process plant.”
On top of this, Australia-based NextOre recently
received a A$1.07 million ($720,995) grant from
the New South Wales Office of the Chief Scientist
& Engineer, through the Physical Sciences Fund, to
adapt its existing on-conveyor MRA to in-pit
mobile mining machinery.
With another A$500,000 raised through a
private placement to support the development
and the help of “a leading global supplier of heavy
mining equipment and service support”, it is
confident of delivering an integrated system that
is “highly adaptable and efficient”, it said.
Beal said the company has also received
interest for a sensor to measure the grade of
62 International Mining | MARCH 2020
material carried in trucks.
“We are working with both manufacturers and
customers on surface and underground
configurations at the moment,” he said, adding
that both will be initially developed for copper
detection and expanded to other commodities.
Similarly, the MineSense team is involved in
both sensor and application developments.
More told IM that the company was currently
working on a commercial installation of its
ShovelSense on the bucket of underground
loaders. This would build on the trials and
commercial ShovelSense installations on
excavators above ground.
“For underground, we think adapting the core
technology will be relatively straightforward and
very applicable to what we have designed for
surface shovels, but one of the things we need to
study is how the sensor deals with, for example,
the top of the bucket coming into contact with the
roof of the mine,” he said. “It’s that physical
contact we need to work on.”
The company already has a trial ongoing at an
integrated nickel operation in Sudbury, which it is
hoping will be converted to a commercial
installation before the year is out.
The MineSense R&D pipeline also includes the
testing of additional sensors on top of its existing
XRF solution.
These would either be standalone sensor types
or a combination of sensors, according to More,
who said he was expecting R&D testing to take
place this year before two new sensor-based
solutions become commercially available, possibly
by the end of 2021.
“These will both extend the metals we can look
at – beyond our current range of copper, nickel,
zinc and iron ore – and also create other value
adds within those four core segments,” he
explained.
While he was not ready to give any information
away on what types of sensors might be included
in a future ShovelSense or BeltSense
(MineSense’s on-belt ore sorting solution)
platform, he did admit retaining the company’s
speed of analysis is of utmost importance in this
process.
“Our XRF systems are right now extremely fast
– faster than any other sensor on the market from
what we see. We see that as one of our core
strengths,” he said. “We will introduce other
sensor types under that objective, looking to
maintain the vast speed of our XRF with these new
sensor types.”
TOMRA is also not standing still.
Having built up a stellar reputation in the
diamond space that has seen many miners
leverage its XRT technology to recover massive
rough diamonds, du Preez said the company is
working on a final recovery solution for this sector
where a TOMRA unit can handle various diamond
streams in a very compact sorter down to 2 mm in
size.
Future adopters
Even with these product enhancements, there will
be no ‘one-size fits all’ approach to ore sorting.
Each solution will be tailored to specific ore
mineralogy, the existing plant in place and the
outcomes a company wants to achieve.
For these solutions to gain great market
adoption, these leaders will need to get
engineering companies on side.
Beal says NextOre is already receiving enquiries
from engineering firms and consultants bidding on
miners’ feasibility work.
du Preez says that TOMRA is an independent
OEM equipment provider that will assist all its
customers (EPCM, EPC, consultants and mining
companies) in flowsheet development and value
optimisation for their respective projects. “It is
really important for us to build strong customer
relationships, in which we are trusted to add value
to the projects with which we are involved in.”
MineSense’s More said the company is also
looking to expand its dialogue with engineering
firms in the next couple of years after initially
demonstrating its technology to miners.
IMA Engineering, meanwhile, is working on ore
sorting projects in South America and Africa.
If these ore sorting focused companies can
establish such a connection, it appears to be only
a matter of time before the OEMs and mineral
processing firms try to strike up some sort of co-
operation agreement or build their own solutions.
As mentioned, NextOre is already working with
an OEM on its in-pit MRA solution and More says
MineSense has informal agreements in place with
shovel manufacturers looking at aspects of the
technology such as application design.
Metso’s SVP for Mining Technology, Olivier
Guyot, meanwhile, confirmed in this same report
last year that the company was “developing
breakthrough proprietary technology to address
the demand of high throughput accurate sorting”.
All this interaction bodes well for the future of
ore sorting technologies in mining, with
flowsheets increasingly being constructed to best
leverage their abilities.
The ‘designer mill feed’ Beal talks about could
then become a reality for every mine site,
eradicating the heated debates that regularly take
place between mining teams and processing
teams.
“Obviously the system that can do that involves
programmable feed systems and that is a much
more sophisticated material handling system than
what is currently employed at most sites,” Beal
said.
“We’ll get there eventually, but it requires the
first implementation of bulk ore sorting and
sensors more broadly across the industry.” IM