SLURRY ENGINEERING/PIPELINES
The new Metso test rig can performance test
pumps with inlet diameters from 300 to 800
mm. A 600 mm calibrated flow meter allows
tested flows up to 9,800 m 3 /hr at a maximum
rated pressure of 7.5 bar. A frequency
controlled 10-pole motor provides a maximum
of 2 MW at 375-750 rpm (50,933 Nm)
less spare parts, to support our customers final
goal, higher throughput at lower cost.
“In our new test rig we are testing the
hydraulic performance, we verify and validate
the flow, head, power and efficiency of the
pump with a larger installed power to manage
higher flows and larger pumps.
“This has been a large investment supported
by the need to deliver larger equipment to the
market, the way we see this is as an investment
in our existing and future customers.”
Examining pipeline costs and reinforcing
some of Andersson’s comments, Rafael Lima,
Ausenco’s Pipeline Director, explains that “there
are several components that make up pipeline
operational costs. Generally the main
Productive
pipelining
Slurry pipeline and pumping costs, pipeline monitoring,
pump news and more from John Chadwick
an E Andersson, Technical Director, Pumps
Business Area for Metso, told IM that 15-20%
of the total cost of processing ore is typically
associated with slurry transportation.
“The wear/power ration varies throughout
the process with the size of the material; in the
beginning of the process, with coarse freshly
fractured solids, wear costs are dominating,
while towards the end of the process, when the
material is finer and rounder, power is the
dominating cost of operation,” he said.
On average, around 50% of the operating
costs of slurry pumps is tied to power
consumption, and centrifugal slurry pump
efficiency can vary by up to 10% if operated at
50% or 100% of its best efficiency point flow,
according to Andersson.
J
Pipeline velocities
Optimising your pipeline velocity is a crucial
part of good pump selection. Should your
velocity be below your minimum settling
velocity, you run the risk of pipe blockage and
(sump blockage) and unwanted stops.
Conversely, high velocity leads to both high
14 International Mining | DECEMBER 2018
wear and increased friction loss that will
increase the power consumption substantially.
Monitoring pump performance, therefore, can
provide “huge savings on both power and cost
of wear parts”, he said.
Metso says it is continuously developing and
expanding its offering to including larger and
more efficient slurry pumps – all offered with a
double-adjust feature to improve overall pump
efficiency and prolong wear life.
As well as developing pumps, Metso has just
recently expanded its slurry pipeline offering
especially suited for mill discharge, high
pressure pipelines and tailings applications.
The company has recently upgraded its test
rig in Sala, Sweden, to test larger pumps with
higher installed power. For instance, it has
recently been testing an MDM650 pump
destined for a copper mine in South America on
this new test rig, equipped with a 2 MW motor.
The company told IM: “Not only do we want
to deliver larger pumps, we also want to keep
delivering pumps that are helping our
customers to lower their energy costs, to strive
for safer and faster maintenance and the use of
operational cost of a mineral or tailings slurry
pipeline is the pumping energy. This component
is followed by spare parts and then labour
costs.
“Both the initial CAPEX deployment and
OPEX costs must be considered in selecting the
transportation means.
“The total pipeline energy consumption is
dependent on product lift or fall and the
frictional loss within the pipe.
“Depending on the pipeline route much of
this transport energy may be provided by
gravity, that is, without any pumping energy
demand.” Commenting on Latin American
examples, he notes that in Brazil a combination
of pumping and gravity are most common. In
the Andes region, where transport begins at
3,000 to 4,000 m and flows to the coastal
regions, very little or no pumping power is
necessary.
“In terrain like that found in Minas Gerais,
Brazil, the energy consumption usually
represents between 60 and 70% of the system
operating cost, thus illustrating the importance
of having an adequate control of this input.
“Generally much of the supply of electrical
energy for mineral concentrate pipeline
transportation in Brazil comes from lower cost
renewable hydroelectric sources; possibly
making it a more environmentally friendly
alternative when compared to other means of
transportation.
“As pipeline equipment has a high
operational factor, spare parts consumption is
relatively low, being below the mineral sector’s
normal 3% of equipment cost.”
“Another important cost factor to consider is
that the necessary pipeline operational staff is