Flotation columns

Flotation columns
For higher
Flotation columns 1
A unique sparger technology
Metso columns cells have established a new standard in flotation
technology. For the last four
decades, columns have proven
their ability to produce higher
concentrate grades compared
with conventional mechanical
flotation cells.
Microcel™ columns increase
product recovery and improve
plant profitability. The sparger is
derived from the patented
Microcel™ technology and
enhances metallurgical performance by allowing an unprecedented flexibility on the graderecovery curve.
Metso offers industrial expertise
and numerous references in fullscale flotation column design,
manufacturing, installation,
commissioning and training.
Metso also supplies testing and
consulting services as well as
laboratory and pilot units.
Flotation columns
At the bottom of the column
the Metso Microcel™ sparger
system maximizes mineral
recovery through:
• Increased carrying capacity due to finer
bubble surface area flux which is a standard parameter in evaluating flotation
• Maximum particle-bubble contacts within
the static mixers.
• Effective reagent activation from the
mechanical operation of the pump.
The general design includes wash water distribution system, internal launders and other
features to produce high-grade concentrates.
Functional description
The Microcel™ sparger consists of in-line
static mixers and a centrifugal pump.
Tailings slurry is pumped from the base of
the column through the static mixers, where
air and slurry are mixed under high-shear
conditions to create the bubble dispersion.
As the air-slurry mixture passes through the
stationary blades located inside the mixer,
the air is sheared into very small bubbles by
the intense agitation.
Fine uniform bubble dispersions, with bubble size typically ranging from 400 to 1200
microns, are generated by the sparger
The bubble suspension is introduced near
the column base, and bubbles rise through
the column collection zone.
The Metso static mixers are wear resistant.
The system is designed for easy operation
and low maintenance and is not subject to
Main advantages
Wash water
Improved recovery
Optimized grade
Increased throughput
Enhanced bubble particle contact
Maximized bubble surface area flux
No plugging
On-line replacement
Reduced wear and maintenance
Air manifold ring
Flotation columns 3
Sparger retrofit
Improved metallurgical performance
Mineral grade %
For plant metallurgists who need to increase recovery, Metso offers to retrofit its sparger
technology on existing columns.
Metso sparger’s ability to improve
column metallurgical performance,
and recovery in particular, has been
demonstrated in every case when
industrially tested in parallel with
other sparging technologies.
Increase in recovery of 30% or more
were reported.
The figure illustrates the performance
changes on column operation
(represented by the grade-recovery
curve) when a Microcel™ sparger is
Increased recovery
Mineral recovery %
1 The initial sparger (air-water or air only
type) allows the column to operate on a
given grade-recovery curve with a limited
flexibility to move along this curve. The
operator has only access to a small operating range for the manipulated variables such
as air rate, wash water addition or froth
height. Typically the concentrate grade
meets full requirements but the column
recovery is poor which translates into high
circulating loads.
Flotation columns
2 The Metso sparger operates on a different grade-recovery curve. This is partly due
to the recycling of the tailings slurry which
acts as a built-in scavenger cell. Under the
same operating conditions, there is a large
increase in column recovery when the
Metso sparger is put into operation. At first
the concentrate grade tends to be slightly
lower which is compensated for in step 3.
Due to both the smaller bubble size produced and the reagent activation provided
by the mechanical action of the recycling
pump, the froth stability is greatly enhanced.
3 Thanks to improved froth stability, the
operator has much more flexibility to adjust
the operating parameters (wash water, froth
height and air rate). As a result, the column
retrofitted with the Metso Microcel™ sparger
generates a significant increase in recovery
with at least the same concentrate grade.
Robust control systems are essential to
ensure product quality consistency and
to minimize maintenance requirements.
Metso supplies the flotation
column control system and associated
instrumentation best suited to you
plant. This may range from one single
control loop to an advanced control
The Metso column technology has
proven its superior metallurgical performances in such applications as
copper, lead, zinc, iron, graphite,
phosphate, coal and fluorspar.
Flotation columns 5
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• Metso Minerals (Sweden) AB
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• Metso Minerals Industries, Inc.
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•Metso Minerals (South Africa) (Pty) Ltd.
Private Bag X2006, 1600 Isando, Johannesburg, South Africa, Phone: +27 11 9614 000, Fax: +27 11 397-5087
• Metso Minerals (Australia) Ltd.
Level 2, 1110 Hay Street, 6005 West Perth, WA, Australia, Phone: +61 8 9420 5555, Fax: +61 8 9320 2500
• Metso Minerals (India) Pvt Ltd
1st floor, Building No. 10, Tower A, DLF Cyber City, Phase - II, Gurgaon - 122 002, Haryana, India, Phone: +91 124 2716666, Fax: +91 124 235 1601
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Calle Vulcano Nro. 156, Urb. Vulcano, Ate, Lima 03, Peru, Phone: +51 1 313 4366, Fax: +51 1 349 0913
• Metso Minerals (Chile) S.A.
Av. Los Conquistadores 2758, Providencia, 7500 000 Santiago, Chile, Phone: +56 2 370 2000, Fax: +56 2 370 2039
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E-mail: [email protected]
Metso Corporation, Fabianinkatu 9 A, P.O. Box 1220, FI-00101 Helsinki, Finland, tel. +358 20 484 100, fax +358 20 484 101, www.metso.com
Subject to alteration without prior notice
Brochure No. 2945-01-15-ESBL/Sala-English
© 2015 Metso Minerals