sensor base sorting new developments - mintek · south africa, witwatersrand gold waste rock dumps...
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Sensor Base Sorting New Developments
United in Separation
Lütke von Ketelhodt 062009
Mintek 75th Anniversary, June 4, 2009
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2002
20062003
2009
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Contents
l Introducing Commodas/Ultrasortl Sorting Principlel Product Linesl Why Sensor Based Sortingl Mineral Applications for Sensor Based Sortingl Sensors within Electro Magnetic Spectruml Colour Sorting Examplesl NIR Sorting Researchl XRT Sorting Examplesl Conclusion
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Commodas UltraSort - Members of in the TOMRA ASand TiTech Group
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TITECH GROUP
Central Europe North America South Africa South America Russia
TOMRA Systems AS, Norway
Food Mining Recycling
Leading global provider of advanced solutions enabling recovery and recycling of materials
World leader in sensor based sorting technology
Listed on the Oslo Stock Exchange
Australia
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Sensor Based Sorting - Schematic principle
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1 Material feed
2 Vibratory feeder
3 Free fall acceleration
4 Sensor - Line scan camera(s)
5 Data processing
6 Air pressure valves
7 Accept stream
Reject stream
8 Network interface for central control
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Mechanical Design
§ Particle size range 16mm to 250mm§ Simple system without moving parts§ Robust§ Compact design, small footprint§ Ideal for double sided scanning
§ Gems & Diamonds - Particle size range 1mm to 30mm
§ High capacity ROM Sorters – Particle size range 6mm to 300mm
§ All individual particles are traveling with the exact same speed before being presented to sensor.
§ Varying density particles can be handled
§ Suited to Multi-Sensor sorting
Chute based Belt driven
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Product Lines
Run of Mine (ROM) Series
Industrial Processing (PRO) Series
Gem Stone (GEM) Series
l Extremely rugged belt sorters
l +6..-300 mm covered by two models
l Sensors RM, PM, EM and XRT
l Simple and efficient free-fall sorters
l +3..-250 mm covered by four models
l Sensors COLOR, EM and NIR, XRT
l Sophisticated wet/dry sorters
l Precon, Recon and SPS systems
l Sensors XRF, XRT COLOR
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Concentrator:ScreeningMillingFlotation
Tailings (fines) Product
Crushing
Run of Mine
Traditional Mineral Processing
Why Sensor Based Sorting?
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Today's Challenges:
l High Energy Cost
l Water scarcity
l Decreasing Head Grades
l Increased Rehabilitations Costs
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l Rejecting waste rock at early stage:
- reduces transport costs- minimises downstream crushing
and milling requirements- reduce surface tailing dumps
l Better utilization of low grade resources
- recovering misplaced reef- improves mill head grades- Consistent mill head grades
l Reduce usage of chemicals
l Saves energy and water
Concentrator:ScreeningDense media separationMillingFlotation
Tailings (fines) Product
Crushing
Removing waste rocksby sensor based sorting
Waste Rock(mine backfill)
Run of Mine
Mining process with pre-concentration
Sorting integrated in Mineral Processing
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Sensor Based Sorting Applications
Base Metals PreciousMetals
IndustrialMinerals Fuel
IronManganeseCopperZincNickelTungstenSlag
CalciteFeldspar Dolomite TalcQuartz Magnesite Salt
Diamonds Tanzanite Emeralds
Diamonds& Gems
UraniumCoal
GoldPlatinum
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Available Sensors within the Electro Magnetic Spectrum
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
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Ultraviolett (UV)
Visible light (VIS)
Near Infrared (NIR)
Microwaves
X-ray
Gamma-
radiation
Alternating current (AC)
Radio waves
[m]
Infrared (IR)
* Under development
Sensor/Technology
Material Property Mineral Application
RM (Radiometric) Natural Gamma Radiation Uranium, Precious Metals
XRT (X-ray transmission) Atomic Density Base/Precious MetalsCoal, Diamonds
XRF Visible Fluorescence under X-rays
Diamonds
COL (CCD Color Camera) Reflection, Brightness,Transparency
Base/Precious MetalsInd. Minerals, Diamonds
PM (Photometric) Monochromatic Reflection/Absorption
Ind. Minerals, Diamonds
NIR (Near Infrared Spectrometry)*
Reflection, Absorption Base metalsIndustrial Minerals
IR (Infrared cam)* Heat conductivity, heat dissipation
Base MetalsIndustrial Minerals
MW-IR (heating in conjunction with IR)*
Sulfides & Metals heat faster than other minerals
Base/Precious Metals
EM (Electro-Magnetic sensor)
Conductivity Base Metals
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Example 1:South Africa, Witwatersrand GoldWaste Rock Dumps
• Grade 0.3 to 0.9 g/t• Fines -16mm blended
into ROM feed to Mill• Oversize +16mm
stockpiled as waste• Some mines tried hand
sorting• Some mines mill the
entire waste dump• Kloof GM Sorting Pilot
Plant 2003/4
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Containerized Sorter, Kloof Gold Mine, South AfricaOctober 2003 – June 2004
•• Sorting gold reef from waste rockSorting gold reef from waste rock•• Size Range Size Range --80 +16mm80 +16mm•• Feed rate Feed rate ±± 80tph80tph
•• Feed grade 0.3 g/tFeed grade 0.3 g/t•• Sorter Concentrate 5 g/tSorter Concentrate 5 g/t•• Mass pull 5%Mass pull 5%
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Full-Scale Gold Waste Dump Plant
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Dump Sorting Plant Key Data:
l Feed to Plant 180 000 t/m @ 0.7 g/t
l Two Product Streams:
- < 16mm Fines - 99 000 t/m @ 0.9 g/t- Sorted reef plus wash-fines 6 000 t/m @ 6.0 g/t
l Combined Product of 105 000 t/m @1.2 g/t
l Gold Produced 124 kg/m (4 000 oz/m)
l Investment Plant USD 3.5 million
l ROI 6 months
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Example 2:Platinum Sorting at Waterval
•• Sorting UG2 from waste rockSorting UG2 from waste rock•• Size Range Size Range --300mm +50mm300mm +50mm•• Feed rate up to 300 tphFeed rate up to 300 tph•• Waste rejected between 20% & 65%Waste rejected between 20% & 65%
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Example 3:South Africa, North West ProvinceAlluvial Diamonds
• Sorting free diamonds from Recovery tailings dump
• Transparency properties
• -8mm +2mm• 10 to 14 tph• Recovered low/non-
luminescent diamonds
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Near-Infrared (NIR) Spectroscopy
l Widely used in recycling
l NIR Spectrometers used to log drill core
l For Sorting Minerals the technology was adapted to have Ø fast processing ratesØ Higher resolution Ø Extended frequency range
l Two measurement chambers Ø Each record 16 channelsØ 2 different wavelength
l A rotating polygonal mirror scans the passing rockØ an image is created for analysis
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NIR Sorting of White Minerals
•• The NIR reflectance spectra shows The NIR reflectance spectra shows clear differentiation between clear differentiation between Talc, Carbonates and QuartziteTalc, Carbonates and Quartzite
•• Good potential for other Good potential for other minerals e.g. Rareminerals e.g. Rare--EarthEarth
•• More research requiredMore research required
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Röntgenröhre
Einzelkorn
Röntgen-zeilensensor
X-Ray Tube
Particles
X-Ray Line Scan Sensor
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XRT Sorter at Mintek
• Throughput 16 – 40 tph• Size Range -40mm +10mm• Compressed air 55 kW ;pressure 8 bar
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Example 1:Coal de-shaling
Shale – SG +1.7
Coal – SG – 1.3
Sample X-Ray Image Simulation Image
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0
10
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1.2 1.3 1.4 1.5 1.6 1.7 1.8
Nominal SG
Part
ition
Co-
Effic
ient
50% Blue 25% Blue 75% Blue
l Cut-point is controlled by sensitivity of program
Partition Curves X-Ray Sorting Coal/Shale
l At 75% blue a cut-point SG of 1.6 is achieved
l At 50% blue SG 1.5
l At 25% blue SG 1.45
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Example 2.Diamonds
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Example 3:Narrow Vein Sulphide-Type Gold
Flat Vein Swarms
Shale
Dolomite
Quartzite/Shale
Granite
Narrow stopes
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Medium-Grade Sulfide ore
Low-Grade Sulfide Ore
Massive -Sulfide ore
ALGORITHM EVALUATION
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ALGORITHM EVALUATION
Quartzite Waste
Norite Waste
Granite Waste
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XRT Sorting of DMS Floats
l DMS Float = XRT Feed grade ~ 1.3 g/t
l XRT concentrate grade ~ 3.8 g/t
l Mass pull 30%
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XRT Sorting of DMS Floats
l XRT waste grade ~ 0.2 g/tl Mass pull 70%
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Features of XRT Sorting
l Dry beneficiation process
l Potential for coal beneficiation in coarse size -150mm +30mm
l Good results for narrow vein-type sulphide oresØ NickelØ CopperØ Gold/SilverØ Polymetallic
l Excellent detection of Diamonds
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Conclusion
l Sensor Based Sorting is a technology gaining significance in the mining industry
l Proven technology (over 150 sorters in mining)
l Recover value from low-grade dumps and marginal ore bodies
l Physical sorting process – no chemicals, heat
l Placing sorter between mine and mill has numerous benefits
l Mill the Ounces , not the Waste!!
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Thank you for your attention !
Questions???
“With the ongoing further development of sensor technology, sensor based sorting will become established as a standard process for pre-
concentration in the future”Professor Hermann Wotruba, University of Aachen