September 2020
PASTE
An INTERNATIONAL MINING Supplement
& TAILINGS 2020
This year’s cover photo shows one
of a series of proprietary tests for
conveyability evaluation of filtered
tailings developed by FLSmidth
www.flsmidth.com
International Mining
2 Claridge Court, Lower Kings Road
Berkhamsted, Herts. HP4 2AF, UK
Tel: +44 (0)1442 870 829
www.im-mining.com
www.im-mining.com
An INTERNATIONAL MINING supplement
PASTE
& TAILINGS 2020
IFC: Reviewing Schwing Bioset's positive displacement pump with optional
continuous flow for a pulsation-free system
P1: ABEL gives an example of how its piston diaphragm pumps can improve
backfill slurry quality
P2: Weir Minerals GEHO positive displacement pumps provide efficient paste
transport while cutting energy usage and water consumption
P4: Paterson & Cooke outlines its view on filtered dry stack tailings including a
European mine example
P6: A review by Golder Associates and Hudbay Minerals of the latest technology
paste backfill plant recently installed at the Lalor mine in Manitoba
P8: Todd Wisdom, FLSmidth Director of Tailings Solutions, talked to Paul Moore
about filtered tailings in relation to best practice, equipment and application
P10: CDE’s Director of Engineering, Kevin Vallelly, says the company’s AquaCycle
water recycling system will ensure operators stay ahead of the curve while
extracting maximum value from available resources
P12: Metso Outotec reviews the success story so far with its Thickener Optimizer
facility at the Yara Siilinjärvi paste plant
P14: WesTech came up with an innovative paste solution for a gold mine in a
heavy rainfall area of China
P16: Amanda Adams from Stantec discusses the new Global Industry Standard on
Tailings Management and what it means for the mining sector
Schwing Bioset's PD pump with continuous flow
One of Schwing Bioset, Inc.'s newest
offerings is its positive displacement
pump with optional continuous flow for
a pulsation-free system. Based on the same
technology used to pump concrete, these wear
resistant positive displacement mining pumps
have been used in both cemented and
uncemented tailings applications.
Traditional piston pumps have a momentary
pause in material flow through the pipeline while
the discharge valve system switches in either a
single or twin hydraulic circuit arrangement. In
certain situations, this momentary pause in
material flow can induce an undesirable waterhammer
effect in the pipeline. Achieving
continuous flow from the piston pump
eliminates the pressure transient created by
these momentary pauses in material flow.
Continuous flow is attained by operating each
hydraulic cylinder of the piston pump
independently. While one cylinder is
discharging, the opposite cylinder
retracts at a faster rate to fill its material
cylinder, then begins to move forward to precompress
the product in the cylinder, such that it
matches the system pressure.
As the pumping cylinder nears the end of its
stroke it begins to ramp down to zero speed.
The opposite cylinder during this period
likewise ramps up its speed proportionally such
that the total volume being discharged into the
pipeline remains constant. Once the pumping
cylinder arrives at a zero speed, it then retracts
at an accelerated rate to charge and precompress
its cylinder, to begin its pumping
stroke again once the opposing cylinder begins
to decelerate. This achieves a virtually constant
flow rate, only limited by the proportional
control ability of the electronics.
With this new development, each working
cylinder operates with an independent control
block to support the required oil flow and
independent discharge valve
switching
The continuous flow pump is ideal for numerous
applications including locating underground for
slimes pumping applications with high pressure
vertical lifts of low solid slurries
system. The independently operating hydraulic
cylinders are equipped with position
transducers which allows their direction,
position, and speed to be controlled
continuously through a PLC.
With the data systems integrated into the
pump the volumetric filling efficiency of each
pumping cylinder is easily calculated and can
provide valuable information for plant
operations reporting on filling efficiency of each
pumping cylinder and tons per hour pumped.
The filling efficiency data also provides valuable
diagnostics information by continually
monitoring wear part performance and enabling
operators to schedule maintenance based on
pump performance maximizing the useable life of
wear parts and lowers overall operating expenses
and avoids costly unplanned shutdowns.
The continuous flow pump is cited ideal for
numerous applications including locating
underground for slimes pumping applications
with high pressure vertical lifts of low solid
slurries in either single or multiple lift
configurations, as well as thickened tailing and
paste applications, or other thin slurry
applications that are prone to pressure
transients developing in the delivery system. IM