WORLD PROSPECTS
Flowrox pumps handle solids at LKAB
lowrox hose pumps were recently chosen for
the LKAB tailings treatment project at its
Svappavaara operation based on previous
experience. “We first learned about Flowrox hose
pumps at a Paste conference in South Africa and
were interested in this pumping technology,” says
Thord Wennberg, Technical Process Development,
LKAB. “We used a LPP hose pump for our first
thickener, but it was not in operation for longer
than one month before we shelved it. We took the
pump out of duty as the slurry was so thin that
pump was not needed. With our second thickener
we knew that our slurry would be thicker, so we
decided to have a go with the hose pump again.
We were aware of the benefits of Flowrox pumps
compared to centrifugal pumps.”
For the new plant LKAB chose LPP-T100 transfer
pumps that are able to pump up to 76% solids. “The
fact that the hose pumps are suitable for paste and
F
Flowrox LPP-T pumps incorporate advanced
single roller design, which eliminates friction
and lowers energy consumption
high-density slurries is important to us. However, at
the moment we are pumping 66 to 70% solids. The
capability of the pumps to effectively pump solids is
very crucial for us in the water treatment facilities.
The slurry is dense enough to enable us to save
water and maintain the flow,” states Åsa Partapuoli,
Senior Process Engineer, LKAB.
“We have been working with the three pumps in
the thickener plant for one year now and they have
been operating well. The most important thing for
us in terms of pump performance is that they
fu nction reliably. All the other benefits come after
that. If a pump is not reliable, there is nothing else
to benefit from,” states Ronny Martinson,
Maintenance and Operation, LKAB. “We have
experienced that the Flowrox LPP hose pumps
handle solids in the slurry better than other
pumps, and that’s very good because we have
occasionally to deal with large particles.”
“The initial lifetime cost
calculation (LCC) for the hose
was estimated at three months.
After the start up and
optimisation of the plant we are
now on somewhat of a normal
duty. If we increase the pressure
and the density, then of course
also the wear increases, which
affects the LCC,” explains Björn
Gardelin, from Minrox, the
Flowrox
representative
in
Sweden. He adds: “The Flowrox
hose pumps incorporate an
advanced rolling design where
larger particles can be handled in high pressure
with minimal wear. The pumps can run dry and be
operated 24/7. The pumps’ rolling design
eliminates friction, maximises hose life and lowers
energy consumption. Flowrox pumps are able to
handle up to 76% solids.”
“They seem to work quite well, and there’s no
need to change the hoses too often. We are now
on a three month hose change cycle according to
the LCC calculation. As I mentioned earlier,
reliability is something that we look for in a pump.
Now we are looking into expanding the hose
lifetime to six months. The only challenge has
been the hose change due to the large size of the
hose and the roll. Luckily, they do not have to be
changed more often than four times a year,”
Martinson adds.
“We are now looking into training the LKAB
maintenance staff to provide techniques and
safety for the hose change, which will make the
work easier and faster but also safe,” says
Gardelin, describing the future cooperation with
LKAB. “We have enjoyed a good relationship with
the customer. We supported LKAB throughout the
project and installation. We had frequent visits and
telephone conferences to solve issues, maintain
contact and provide support.”
LKAB’s ambition is to increase production by
5% a year up to 2021. This will entail increasing
capacity and efficiency also in the waste and
tailings treatment. LKAB has already placed an
order for a fifth pump for the project. LKAB
Svappavaara is one of the oldest pelletising plants
in Sweden and LKAB the second largest producer
of iron pellets in the world. With annual production
of iron ore products amounting to 26.9 Mt in 2016,
the annual tonnage of tailings disposal is also
considerable. For decades LKAB used a dam as
disposal method for tailings, but in 2012 the
company decided to deposit the tailings in
Svappavaara at a high solids content and
introduced a project to build a tailings thickening
facility. www.flowrox.com
Evolution at Robit
T
4 International Mining | OCTOBER 2017
behave, how rock fractures,
how to harness the
immense forces travelling
within the drill string. The
best part of this is the
quantifiability, the simple
microstructure that makes
itself visible after asking so many questions. We
have the answers to where the Evolution
performance comes from and what it means to
your drilling process.”
The Evolution series scope of improvements
share multiple aspects across the size range,
drawing from the simulation and analytics-
based approach exemplified by advanced fluid
dynamic simulation being used among other
tools. At the small end, development focused
especially on the specific needs of high power
and high frequency drilling in tunnelling and
drifting applications. Multiple model approaches
were taken, with the boldest design boasting
just six extra-large buttons in a 48 mm bit. “All
variants were extensively tested with our
CFD simulation images showing how the
conventional model (left) has a dead space in
the centre of the bit where airflow velocities are
low. The Evolution model (right) has an more
even flow pattern, and increased airflow at the
centre of the bit and through the secondary
side channels
customers and set against conventional hard
rock bits. In the end the best results were
gleaned from modifications and optimisation to
face design, but particularly from increasing
both gauge and face button numbers as well as
increasing the number of flushing holes. The
test results of the Evolution bit in hard
Scandinavian granite were very impressive, with
grinding intervals up to 60% longer and lifetime
he 30-year history of Robit has seen an ever-
increasing need for the connection between
hammer and rock to endure more severe
forces. In recent years, top hammer performance
development has not only been linear but
exponential, as maximum impact powers in
tunnelling and drifting applications rise above 40
kW and impact frequencies steadily reach beyond
100 Hz. The company states: “Robit Button Bits,
now used across the globe in a vast variety of
rock formations, have witnessed masses of
improvements during the journey. We’ve listened
to our most experienced customers working in
the toughest conditions, tested again and again,
failed and succeeded, tweaked and reinvented,
all the time working on what matters most –
getting drilling right, every time.”
The new Evolution bit series is the result of a
systematic approach towards crafting the world’s
best button bits. “Our level of sophistication is
growing, trial and error has ages ago been
surpassed by simulation and analytics-based
development. We know how our materials