minpro thickening technologies

Thickening technologies

Leading edge technologies for thickening and clarifying

Outotec is the global leader in the design, fabrication and supply of thickening and clarifying solutions for the minerals industry. The revolutionary SUPAFLO® high rate thickener has pioneered and redefi ned thickening and clarifying methods around the world.

Innovation is standard

SUPAFLO® thickeners and clarifi ers operate in minerals processing, chemical, water treatment, industrial and effl uent applications throughout the world. The fi rst SUPAFLO® thickener was installed in 1985, and the many innovative features of these units, including an ongoing commitment to testwork, research and development, and after sales service, have ensured their rapid acceptance in a wide range of industries. Outotec’s worldwide network manufactures and supports SUPAFLO® thickeners, with design offi ces in Australia, China, Europe, North America, South America and South Africa. This means that no matter where you are, SUPAFLO® advanced technology is easily accessible to you. SUPAFLO® thickeners include a number of innovative features in their design. Special attention is given to engineering design of feedwells, rake profi les, drive systems and control strategies to meet the challenge of dewatering materials that are often problematic for normal thickeners. Our experience in testwork, design, operation, installation and service of thickeners and clarifi ers throughout the world is your guarantee of quality.

SUPAFLO® thickeners and clarifiers

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Advantages of SUPAFLO®

Low capital costOptimized designHigh rate units reduce area

by up to 90%Precise test work procedures

allow accurate sizingLow operating cost

Patented ”Autodilution” systems minimize fl occulant consumption

Floc-Miser feedwell ensures effi cient fl occulation

Simple control system provides stable operationGuaranteed performance

Bench-scale and pilot tests provide data for direct scale- up and written guaranteesHigh reliability

Patented ”low drag” rake arm reduces torque loading on drive

Proven hydraulic drive and rake lift offers three levels of system protection

Robust control systemShort delivery time

Full range of CAD designs are quickly tailored to customers' needs

Global sourcing networkWorldwide service

Laboratory and on-site testingDesign offi ces in North America,

Australia, China, South America, Europe and South Africa

Ongoing process and technical support provided through local offi ces

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Copper tailings, Chile.

Paste thickeners, Australia.

Copper tailings, Chile.

Paste plant, Sweden.

Gold tailings, Australia.

Lime saturator, Australia.

Sludge clarifi er, Australia.

Mineral sands tailings, Australia.


Complete service

TestworkThe bench or pilot scale testwork can be conducted either on site or in one of our laboratories around the world. Process guarantees are given based on test results.

SelectionThe testwork results and our previous experience are used to select the appropriate size and type of thickener or clarifi er to satisfy the process requirements for each application.

DesignThe selected unit is tailored to the needs of the user in one of our regional CAD design offi ces.

FabricationOur project engineers monitor fabrication to ensure that the equipment quality meets all aspects of our ISO 9001 accreditation.

InstallationWe provide complete installation or supervision as required.

CommissioningMechanical and process commissioning is also performed by Outotec trained engineers.

Process and technical supportProcess advice, technical support and service are provided through the Outotec worldwide network.

Our product range includes:

SUPAFLO® high rate thickeners

SUPAFLO® high compression thickeners

SUPAFLO® paste thickenersSUPAFLO® conventional

thickenersSUPAFLO® clarifi ersSUPAFLO® solids contact

clarifi ersSUPAFLO® lime saturators

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Bench-scale and pilot plant testwork

High rate thickeners and clarifiers

The method generally used to accurately determine the size and expected performance of SUPAFLO® high rate thickeners and clarifi ers is dynamic bench or pilot scale testwork, as static settling tests do not adequately simulate the high rate principle. Continuous bench-scale tests are performed in our 100 mm (4”) diameter dynamic thickener or clarifi er at site or in our laboratories. A sample of slurry containing 10–25 kg (22–55 lb) of solids is all that is required for a series of tests to determine underfl ow density and overfl ow clarity for a range of feed rates and fl occulant dosages.

Pilot plant testing

We can supply pilot scale thickening and clarifying equipment to meet your process requirements. The size and confi guration is based on material characteristics and performance goals. We have units for conventional settling, high rate thickening and/or clarifying, high compression and paste thickening. Typically a one meter (3.28 ft) diameter skid-mounted pilot unit complete with a fl occulant make-up system, automatic fl occulant addition and underfl ow withdrawal, is available for on-site testwork. A feed rate of 1-8m3/h (4.4-35.2 US gpm) of pulp is required for the pilot plant thickener/clarifi er. A database of all SUPAFLO® thickener test results from around the world is constantly updated for preliminary thickener sizing and to assist in selection of full-scale units.

Testwork is required for the selection of correct thickener or clarifier size and configuration for your

application. Outotec is renowned for its professional testwork service using cylinder settling tests,

continuous dynamic bench-scale tests and pilot plant tests.



SUPAFLO® high rate thickeners and clarifi ers

Floc-Miser feedwellDe-aeration chamberDefl ector plateControlled bed levelHigh throughput per unit areaFree standing or in-ground tanksShort retention timeOptional underfl ow recycleClear overfl ow

Our high rate thickeners and clarifi ers are suitable for all applications where fl occulants can be used in the process. Also ideally suited to clarifying, with overfl ow being fi ltered through a fl occulated solids bed. External underfl ow recycling is sometimes used to improve fl oc formation and particle capture.

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SUPAFLO® high compressionthickeners

Floc-Miser feedwellDe-aeration chamberControlled bed levelHigh throughput per unit areaFree standing or in-ground

tanksHigh rake torque capacityExtended high compression zoneSupapickets (static and

rotating) for improved water release

Increased underfl ow density

SUPAFLO® high compression thickeners provide consistently higher underfl ow density while maximizing solution recovery. They are used for increasing tailings dam capacity, counter-current decantation, increasing fi lter capacity and increasing recovery of process water or chemicals.

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SUPAFLO® paste thickenersFloc-Miser feedwellDe-aeration chamberControlled bed levelHigh throughput per unit areaFree standing tanksHigh rake torque capacityExtended high compression zoneSupapickets (static and rotating)

for improved water releaseMaximum underfl ow densityUnderfl ow slurry yield stress

>200Pa

THE SUPAFLO® paste thickener is designed to produce a consistent paste underfl ow with process control and mechanical reliability second to none. Primarily used for tailings disposal and pre-leach applications. Paste thickeners can be used for any application where underfl ow yield stress in excess of 200Pa is required.

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Nickel tailings, Australia. 5 x 20 m paste thickeners shipped to New Caledonia.


SUPAFLO® conventional thickeners and clarifiers

Small or shallow feedwellFlocculants not essentialInsensitive to short-term

process changesDrive and rake torque to

suit application

Conventional thickeners and clarifi ers are available as ”traditional” conventional units or fi tted with fl occulating feedwell. Hybrid versions are also available in which various design features of our high rate thickeners are used, for particular applications. These modifi cations can result in improved overfl ow clarity, lower fl occulant usage, higher feed rates and improved control.

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SUPAFLO® solids contact and reactor clarifiers

Combines fl ash mixing, fl occulation, clarifying, sludge collection and thickening in one operation

Minimizes chemical requirements by using the solids contact or seeding principle

Variable speed impeller and separate rake drive mechanism

Deep clear water zoneInternal or external recirculation

optionDual chemical dosing option

A variable speed impeller can be used to internally recirculate and mix fl occulated underfl ow, raw feed and chemicals to optimize fl occulant usage and overfl ow clarity. Typically used for water or waste-water applications, where chemicals are added to enhance fl occulation andsedimentation.

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Lime saturatorsSaturated lime solutionsOver 85% usage of available

Ca(OH)2

Variable speed impeller and separate rake drive mechanism

Controlled sludge levelHigh rate feedwell for improved

solids dispersionInternal or external recirculation

option

Lime saturators are used to make clarified saturated lime solution for drinking water plants. Milk of lime solution is fed continuously into the reaction zone, where it is mixed with recycled sludge. The sludge is controlled at the required level by varying the sludge withdrawal rate.

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Copper concentrate, Argentina. Lime saturator, Australia.

Feedwell features

The heart of the thickening or clarifying process begins with effective fl occulation. The SUPAFLO® Floc-Miser feedwell addresses the key elements of this process by controlling the mixing and contact conditions in a unit reactor. In-house CFD modelling in addition to independent analysis has shown the SUPAFLO® feed system is superior to others available in the market.

Key elementsDe-aeration of feed slurryControlled mixingControlled pulp injection velocityVariable depth fl occulant spargersRestricted bottom exit to eliminate short-circuitingDensity optimisation

Autodilution system

To decrease the feed solids level prior to fl occulation, SUPAFLO® has developed the patented ”Autodilution” system which harnesses the natural head difference across the feedwell wall to drive supernatant liquor into the feedwell where slurry dilution, mixing and fl occulation take place. ”Autodilution” maintains the density in the feedwell within the optimum range for fl occulation, irrespective of feed fl ow rate or density.

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Turbodil™ system

In some circumstances, the process dictates that an alternative feed dilution scheme be adopted. Such circumstances include:

A very high degree of feed dilution required by the process

The requirement for dilution systems to operate over a wide feed volume variation

Thickener operation with coarse particle sizes and simultaneous requirement for dilution to low feed solids

Very large feedwell diameters where mixing energy over and above that generated by the incoming feed needs to be provided

Outotec has developed a patented system of forced dilution – Turbodil™ – using low head axial pump to drive dilution water into the feedwell.

Retrofit and benefit

The benefi ts of the SUPAFLO® Floc-Miser feedwell in both conventional and high rate thickeners are dramaticly:

Reduced fl occulant cost – an investment in a Floc-Miser feedwell is usually recovered in 3–12 months

Increased settling rates i.e. higher solids throughputs

Increased underfl ow density for a given fl occulant dosage

Elimination of dilution water pumping costsImproved CCD wash effi ciency

Many thickeners have now been retrofi tted with the Floc-Miser feedwells, including large conventional thickeners of up to 90 m diameter.

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The high rate Floc-Miser feedwell

S.G = 1.0Overflow

Floc-MiserFeedwell

S.G = 1.1Feed Slurry

S.G = 1.05Fluidized Bed

Dilution Water

S.G = 1.6Thickener Underflow


0 4 8 12Time (hrs)

Und

erflo

w %

Sol

ids

16 20 24

Larger OscillationLower Average Density

Smaller OscillationHigher Average Density

Normal Contrr ol Strategyt

Supaflo Contrp ol Strategyt

Average Densityr

Outotec specialists provide expertise for the control and operation of the thickening process.

Control philosophy

Control systems are built around two fundamental and simple control loops:

Flocculation is controlled by varying the fl occulant pump speed to achieve a consistent fl occulant dosage rate per tonne dry solids feed. Bed level is used as feedback to control the g/tonne set point.

Solids inventory is controlled by varying the underfl ow pump speed to achieve a constant bed mass.

By controlling flocculation and solids inventory, the thickening process is stabilized and a consistent underflow density is achieved.

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SUPAFLO® high rate thickener control

MFM

LT

PT

Floc

Feed

Overflow

Underflow

Typical froth problem. Froth removal after Frothbuster™Frothbuster™

Froth management

For concentrate thickeners directly downstream of fl otation processes, froth contamination of the thickener surface and overfl ow can be problematic. Surface froth can result in:

Loss of productIncreased maintenance costsReduction in thickener performance

Froth Collection

Froth collection is achieved by means of a froth baffl e, rotating booms and a collection box. Froth is swept in to the box and removed from the thickener surface. Sprays are used in conjunction with the system to reduce surface froth. Frothbuster™ Deaeration

Frothbuster™ removes air from the thickener feed slurry prior to the thickener feedwell. This improves fl occulation and dramatically reduces the amount of fl oating froth.

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Hydraulic rake drive

A slow-speed hydraulic motor, acting through a high-effi ciency planetary gearbox, is used to drive the rakes.The optional rake lifting mechanism comprises a numberof hydraulic cylinders operating in parallel, which raise and lower the drive base. SUPAFLO® rake drives are designed to meeteach specifi c application, using off-the-shelf components wherever possible. This system has distinct advantages over traditional multi-stage electromechanical drives:

Planetary gearbox gives excellent torque and thrust load capabilities

Accurate torque measurement through hydraulic pressure

Three levels of drive protectionIntrinsically safe rake liftReversible

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Outotec pioneered the now universally accepted use of planetary gearboxes on full span bridge

thickeners. Our drive range encompasses single planetary and multi-pinion gearboxes with

hydraulic or electro-mechanical designs for full span and centre column thickeners.

Drive protection and rake lift

The SUPAFLO® hydraulic rake drive offers three levels of drive protection:

The pressure on the main hydraulic drive is monitored by a pressure transducer which activates the automatic rake raise/lower function

An independent pressure switch also monitors the hydraulic pressure and activates an alarm and motor trip at a higher pressure set point

The fi nal level of protection utilizes a pressure relief valve in the hydraulic circuit to guarantee the drive never exceeds the design torque rating

No possibility of over-torque on start-up

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High capacity drive systems

Rake lift – lowered position. Rake lift – raised position.


SUPAFLO® column drives (SCD) and bridge drives (SBD)

Our engineers have developed high capacity multi-pinion drives, using the latest gear manufacturing technology, specifi cally with maintenance in mind. The ring gear and pinion components are readily available from major manufacturing centers around the world.

Standard drives are available, from 750 kNm to 8750 kNm, and feature:

Commercial one-piece ring gear and bearingInduction hardened metric module gear teethOil bath lubrication of gear and bearing assemblySplined drive from reducer to pinionSelf-aligning lower pinion bearingHydraulic drive for load balancing between pinionsFabricated base housing designed by FEAStress relieving all fabrications prior to

commencement of machiningOptional hydraulic rake lift

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The maintenance features:Single pinion assembly units can be removed

without draining oilSpherical roller lower pinion bearingsNo upper pinion bearing required

The rake lift on all center column drives is easily accessible, above the drive head. Drives can remain in operation with a single pinion removed for maintenance.

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SUPAFLO® multi-pinion drives

Copyright © 2007 Outotec Oyj. All rights reserved.Outotec and More out of ore! are registered trademarks of Outotec Oyj.

[email protected]

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Outotec, formerly Outokumpu Technology, is a worldwide

technology leader providing innovative and environmentally

sound solutions for a wide variety of customers in minerals

and metals processing as well as related process industries.

Outotec Oyj is listed on the OMX Nordic Exchange Helsinki.

minpro thickening technologies

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