SLURRY ENGINEERING/PIPELINES
FLSmidth’s newest Krebs slurryMAX™ split
case design pump, with multiple liner and
impeller material options
end parts is among the benefits of the slurryMAX
pump, as are its heavy-duty shaft and taper roller
bearings that cannot be over greased; these
long-lasting bearings are rated at a minimum of
100,000 hours.
This year Flowrox released a new generation of
Flowrox PC Pumps; the E and EL Series with
improvements made in pump construction,
resulting in cost effective investment. PC pumps
are ideal for demanding industrial slurry and
paste pumping applications, especially with high
viscous or shear sensitive liquids and sludges.
The new pumps are lighter and can fit into a
smaller place. Because of the simpler structure
of the PC pumps it is also much easier to replace
existing pumps. These E and EL series pumps can
be easily tailored to customer needs.
PC pumps can pump nearly pulsation-free.
Pumped medium continuously shifts spaces
(progressing cavities) between the rotor and the
stator which almost completely eliminates
pulsation.
Flowrox technology enables the PC pumps to
deliver up to 10 bar of pressure per single stage.
This is possible with the spiral stator that forms
the heart of the whole pump. Furthermore,
comparing Flowrox PC pump performance with
conventional PC pump, Flowrox 2/3 geometry
pumping elements need less rpm than
conventional 1/2 geometry pumping elements to
achieve the same flow rate.
Other benefits of Flowrox PC pumps are:
n Over 30% higher pumping capacity compared
to a conventional PC pump with same rpms
n Save energy up to 15% compared to a
conventional model
n Minimised maintenance time enables the
highest run time possible, Flowrox claims.
Slurry pumping from mine ponds
Regular engagement with Rio Tinto’s QIT
Madagascar Minerals (QMM) operation and a
good understanding of local conditions allowed
Weir Minerals Africa to provide the optimal
18 International Mining | DECEMBER 2018
solution to the
customer’s recurring
challenge on a process
pond. Weir Minerals
Africa’s Dewatering
Product Specialist Neil
Matthews explains that
the mine was
experiencing continual
collapse of the 20 m
suction hose to the
Warman® AH® 12/10
pump mounted on a
skid at the back of the
pond. This resulted in the need to keep priming
the pump and was causing regular downtime.
Technical features of the new E and EL series
Flowrox PC pumps are
• Combination of an elliptic rotor and a stator
with even wall thickness
• More pressure with less strain
• Increased flow per revolution
• Long rotor/stator lifetime
• Less backflow
“Unpacking the issues facing the
customer was the first part of
upgrading the mine’s process water
utilisation,” says Matthews. “We
discussed several options with the
customer after which our dewatering
and engineering teams collaborated
closely to design a solution. It was
vital to carefully consider the problem
in the context of the geographic and
site conditions, as well as the local
fauna and flora.”
To provide the most suitable Weir
Minerals products and solutions, the
team specified a Warman ® AH ® 10/8
pump mounted on a Multiflo ® pontoon with the
pump coupled to a variable frequency drive (VFD)
facilitating greater flexibility in dealing with
varying site conditions. A second pontoon was
fitted with a Warman ® AH ® 6/4 pump with motor
and fixed speed drive as design conditions
should remain constant throughout the life of
mine.
Both pontoons are connected to a floating
docking station which is, in turn, connected to a
20 m walkway fixed to the bank-side landing.
“It is standard practice in most of our pontoon
designs to mount the pump sets at 30o to
submerge the suction eye of the impeller, thereby
ensuring consistent priming,” Matthews says.
Madagascar’s weather conditions, which
include regular tropical storms and high wind
speeds, were one of the most important factors
affecting the solution. These conditions can
create wave action and wind loading on the pond
during storms which the pontoon solution has to
accommodate.
To address the wave action and minimise
possible structural damage, the fixed walkway
was designed to incorporate a pivot system on
the bank landing structure. This allows the entire
assembly, including the docking station, to rotate
90o and still be tied down to the shore during
these storms.
“Our design took all the site conditions into
account, making for better and more predictable
operational reliability,” he says. “Both the
pontoons and the pumps can now be easily
moved for servicing or for securing during bad
weather.”
He highlights that Weir Minerals Africa’s
team’s experience with mounting pump sets onto
pontoons and their extensive process-related
knowledge played a significant role in developing
the product offering for the customer.
With their almost linear flow without deviations
and minimum wear FELUWA pumps are
especially suitable to handle aggressive and/or
abrasive, solids carrying media, e.g. mine
slurries and waste materials - even at high
viscosity. The linear flow path of the medium
and the fact that it is only in contact with the
internal hose-diaphragm and the check valve
reduces erosion and corrosion to a minimum.
Aggressive and abrasive fluids are not in contact
with the pump casing rendering special
materials, resistant to the medium, unnecessary