Transcript Mine Based Pre-Concentration

Mine Based
Pre-Concentration
Ben Murphy
Cobar Mining Seminar - 9th August 2010
Overview
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Introduction – Technology & Challenges
Lean Mining and Waste Elimination
Pre-concentration – Suitability and technology
The Python Concept
Mining Sector Issues
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Few “simple mining and metallurgy” large ore bodies left
Existing ore bodies –deeper and increasing complexity
Escalating capital on large fully engineered plants
High costs around developing smaller ore bodies
Long environmental permitting
Power and water supply issues
“Economies of Scale are great but what if the
ore body is simply not big enough?”
Lean Mining Analysis
Transportation
Inventory
The Seven Wastes
Motion
Waiting
Overproduction
Over Processing
Defects
Lean Mining Applied
(McCarthy, 1999)
Mine Based Pre-concentration
Integrated UG Mining and Processing System Model (Bamber, 2004)
Pre-concentration Benefits
• Reduced transportation costs
– Haul distance – smaller equipment / less energy
– Haul Mass – smaller equipment /less energy
• Smaller Inventories
– Smaller higher value stockpiles
• Over processing
– Valuable losses to fines
– Savings in power and chemicals
TO MAXIMISE BENEFIT
•MINIMISE DISTANCE TO MINING
•MAXIMISE WASTE REJECTION
Pre-concentration Benefits
• Savings on mining costs
of 20-50%
• Numerous studies in the
literature to support this;
– Bamber et al
– Lane, Fountain & Brooy
– Dominy, Gray & Daffern
Pre-concentration Benefits
• In addition
– May allow alternate mining methods (narrow vein)
– Backfill opportunities
– Permitting benefits
– May allow mining of small satellite ore bodies (surface)
– Increase mine life – expand reserves
“For successful application integration
into mining systems is critical”
Pre-concentration Technology
• Pre-concentration not a new thing
• A rose by any other name……..
• Often applied at front end of the plant
Decreasing Grade
Mine
Mine
Mine
Smelter
Flotation
Plant
DMS
Plant
Flotation
Plant
Smelter
Smelter
(Bamber, Klien, Morin, Schoeble, 2005)
Pre -concentration Technology
Suitability to Pre-concentration
• High grade into low mass – high gangue rejection
• Coarse liberation
• Mineralogical examination and lab test work
100%
90%
80%
70%
Recovery
60%
50%
40%
Au Dis tribution
30%
S Dis tribution
Ag Dis tribution
20%
10%
0%
0%
20%
40%
Yield
60%
80%
100%
Yield-Recovery Concept
100%
90%
80%
70%
Recovery
60%
50%
40%
Au Distribution
30%
S Distribution
Ag Distribution
20%
10%
0%
0%
20%
40%
Yield
60%
80%
100%
Pre-concentration Methods
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Size
Density
Colour / Fluorescence
Magnetism
Surface Chemistry
Radioactivity
Scalping and screening
Dense Media or Gravity
Optical / x-ray sorter
Magnetic Separators
Coarse Flotation
Radiometric Sorters
(Bamber, Klien, Schoeble, 2006)
Optical Sorting Flowsheet
Gravity - Flotation Flowsheet
Mine Based Case Studies
Selected Case Studies from Literature
Company / Mine
Metal
Method
Waste
Rejection
Au
Gravity
98% +
INCO / McCreedy East
PGM
DMS
22-55%
Falconbridge / Thayer*
Ni
DMS
14%
Falconbridge / Fraser
Cu
Ore sorting
44%
Central Rand Gold / South Deeps*
Au
Gravity / Flash
Flotation
90%+
Welsh Gold / Gwynfynydd*
* Operational Mine Based Pre-concentration sites
Python – The Concept
Design Envelope
– Fit in an UG drive
– Transportable
– Minimal Civils
– Plug’n’play
– Low water
– Low power
Python – The Concept
Designed for mobility and flexibility
Pre-concentration focus
13 Modules including MCC’s
5 dry modules, 6 wet modules, 2 electrical
Python - The Reality
Mine Based Preconcentration
• Has the ability to provide step change improvements by;
– Reducing mine transport costs
– Reducing Inventories
– Reducing Over processing
• To maximise its potential it is important to;
– Minimise the distance from mine to plant
– Maximise the waste rejection
• Potential savings of 20-50% of the mining costs
“Damit,….I don’t have
time for this sales man, I
Have a war on my hands”
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flash
size um
3
9
15
53
10
6
21
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IPJ
42
5
85
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% recovery
Combined Size by Size Unit Gold
Recoveries of IPJ and Flash Flotation
Vertical Shaft Impactor (VSI)
• Rock fed into the top of the
machine.
• Feed accelerated, leaves
rotor at 60 m/s.
• Rock on rock crushing
• Handle large variation in
moisture content, ideally
suited wet screened
products
• Can handle multiple feed
sizes (30:1 reduction ratio)
Recovery from Gravity + Flotation
100
90
Recovery (%)
80
70
60
50
40
30
20
10
0
0
100
200
300
400
Size (um)
500
600
700