Transcript TRANSFORMING THE EFFECTIVENESS OF THE HPGR CIRCUIT …

Facing the challenges of new low-grade
orebodies with new economic circuit designs
Malcolm Powell
JKMRC - Queensland
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Flexibility to create value
Driven by uncertainty & variability
• Modify process to respond to uncertainty (S. Begg)
• Vary processing routes to respond to known variability (Powell)
Embrace uncertainty to develop a new range
of economic/business options
The variability of what comes your way
will drive flexible processing
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DRIVERS
Comminution 36±10% mining energy
Energy
Ballantyne 2011
Water
Massive low-grade ore bodies
Gold
Copper
Increasing demand
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A new mining era – a ‘New mining industry’
• Considerably more challenging orebodies
– rapid expansion by exploiting
previously uneconomic deposits
• Rapidly increasing production costs cannot be sustained by
continually increasing commodity prices
– illustrated by the recent downturn in the industry
4
Reduction in grade
• processing of 50 to 100% more ore
same amount of metal
• + finer grain structure - finer grinding
more challenging recovery
tweaking current technologies and relying on economies of scale
will not turn the industry around
Switch to considerably more efficient processing
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Current approach
Throughput
Collapse the rich orebody information to a standard single figure
used in machine selection and circuit design
Production prediction linked to conventional circuits
average product size
equipment gigantism
Current approach is to extract less metal from more ore
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Conventional design - locked in history
RISK is underperformance for the new orebodies
Conventional circuits operated at historic inefficiencies
Product
cyclone
RoM
SAG
Ball Mill
Sump
Pump
Geometallurgical Modelling
– at great cost and effort –
No Upside
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Upside
The value-add of seeking upside
In variability there is a lot of upside
yet we choose to smooth and ignore
blending and daily operation
Limit
New average
average
Process output
lost opportunity in daily operation
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Feed quality - extremely variable
1 row of blocks
23
Conditional simulation
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• Grade:
0-3
19
0.5
-1
17
• Size (F80)
15
40
– 130 mm
ET
kWh/t
• Competence
13
11
Product requirement
9
• 40 – 100 µm
7
Time
Specific energy requirement
• 11 – 33 kWh/t
10 yrs
1399900
1399975
1400050
1400125
1400200
1400275
1400350
1400425
1400500
1400575
1400650
1400725
1400800
1400875
1400950
1401025
1401100
1401175
1401250
1401325
1401400
1401475
1401550
1401625
1401700
1401775
1401850
1401925
1402000
1402075
1402150
1402225
1402300
1402375
1402450
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• Process fixed at 20±2 kWh/t !
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Future approach - Utilise variability
Utilise the properties of the orebody – variability
revolutionising our processing techniques
Our new mantra:
‘Selective mass mining’ with flexible processing
It is time to extract more metal from less ore
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Future approach
Circuits designed to respond to variation in:
–
–
–
–
grade
competence
feed size distribution
liberation size
by processing to varying:
– target grind size
– recovery options
– cut-off grades
Considerable, worthwhile challenge to ensure sustainability of our
industry
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FlexiCircuits
“FlexiCircuits leverage ore variability to maximise resource utilisation”
Providing a range of alternative processing routes for a rock.
Investigate processing options that provide extra capacity
through sophistication rather than scale
smart ore characterisation
economic modelling
innovative processing plant design
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Novel Flexible Circuits
A choice of processing routes
• respond to a wide variability in ore properties and throughput
requirements
– Shift workload
• slash processing costs and energy utilisation
– Blast control
– Reduced milling requirement
– Progressive upgrade
• while enhancing overall recovery
– Higher feed grades to flotation
– Alternative recovery routes
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Enabling Technology
Novel processing routes
Novel or new application of equipment
Devise and test the potential new processes
Requires
Ability to model equipment and circuit performance with confidence
Circuit Simulation
Individual machinery
is useless
Circuit response
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Examples applied to novel flexible circuit design
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Uneconomic ore-body to viable
Ore body knowledge
Ore body knowledge
Smart blasting
Waste rejection
Tag & load
Gyratory
60mm screen
Bulk grade detector
Bulk sorter
Waste stockpile
splitter
Flotation
Low-grade SP
Split stockpile
Pebble
crusher
Delayed processing
cyclone
screen
Ball mill
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From uneconomic to viable
full
tph
upgrade
% of full
10000
6756
68
recov, %
80
82
103
Cu, tpd
960
952
99
Power, MW
113
72
64
specific power, kWh/t
11.3
10.7
95
2 to 1 processing reduction
2x40 ft SAG, 2x26ft ball mill
1x42ft SAG 1x28ft ball mill
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Ore body knowledge
Know what is coming your way & plan when
Courtesy CSIRO
Model Cells Contain processing parameters
Courtesy CRC Ore
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Utilise variability – e.g. Blast Engineering by Grade
Coarse low grade
Fine High
Grade
Ore
1.0
0.25
Coarse Waste
Conventional Blast
Coarse
Low
Coarse Waste
Grade
Finely Concentrated Ore
Frequency
0.8
0.2
0.6
0.15
0.4
0.1
0.2
0.05
00
0
0
50
5
100
10
150
15
200
20
Fragmentation Size (mm)
250
25
300
30
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Ore body knowledge + flexible flowsheets
Know what is coming your way
Smart tag
Process
route
Grade detector
Deferred stockpile
Grade detector
No grinding media
60% total energy
Fine waste rejection
Stable product
+ 3% recovery
+25% metal
production
Upside
40% capacity
AG→SAG
Reduced RISK
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Hybrid Circuit
- HPGR - AG
RoM 2000tph
5000tph
> water recovery
< viscosity issues
Dry Clay clumps
Dry fluidised bed separator
LG circuit / heap leach / waste
50mm
20mm
•
•
•
•
Cone
crush
HPGR Feed 2200tph
Waste
sorting
HPGR
70% energy
Stable product
Higher recovery
Reduced RISK
Rejects
3-product cyclone
5mm
600 tph
Middlings
SAG
ball Mill
Sump
Pump
concentrate
Coarse
flotation
Tailings
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High quality ore body knowledge
• Model feed as average
– little advantage in complex circuit
• Model variability of feed
– advantages of hybrid flexible circuit over SABC circuit
– response to ore variability
– Multi-component simulation with advanced models
Tuning variable processing to the variable processing regimes
critical to advanced circuit development
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P80?
Hybrid + Stirred Mill
Smart Blast Design
Grade
splitter
P80?
sorter
P80?
Coarse
Gangue
Sorting
Multi-comp
Sorting
crusher
Rejects
P80?
Coarse Waste
To Flotation
Pebble
3-prod
Rejection
cyclone,
multi-comp
Stirred
Mill
Secondary
Crusher
ROM
Grade-byPrimarysize
Gyratory
Crusher
P80?
Multi-comp
HPGR =
P/W
P/W
Fine
grinding
Tert
Grind
Cyclones
Primary
Cyclones
SAG
Mill
P80?
Middlings
2mm
P80?
C
C
C
C
HPGR
Bimodal feed,
multi-component
SAG
Ball
Mill
P80?
Coarse flotation
10mm
80mm
20mm
Coarse
recovery
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Uptake
• Characterise ore
– Base properties
– Apply to variable circuits
• Model & Simulate
– Multi-component
– dynamic
• Pilot
– larger capacity
– process options
• Control
– Dynamic simulation
– test on large pilot plant (10 tph)
• Engineer
– Physical layout
– Turning concepts into reality
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Equipment suppliers & Engineering companies
Transform complexity into elegance
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New Mining Industry
Exploiting lower grade and less favourable ore bodies
→ Doubling comminution energy and processing equipment
→ Unviable
Geomet
• higher resolution of ore body knowledge
• tracks ore variability
• linked to flexible processing incorporating ore upgrade options
Transform currently uneconomic resources into viable and reliable
reserves
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Flexible circuits – Go Hybrid
Design & build with today’s technology,
while allowing the uptake of tomorrow’s technology
for tomorrow’s challenges.
P.S.
Invest in research,
not mills
Ensure:
Continued licence to operate
Sustained profitability in the long-term
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Considerable team effort
Hacettepe
TU Braunschweig
CMR Rio de Janeiro
Chalmers
Cape Town
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Future value
Resource definition (Geomet)
Feeding into
Flexible processing options
Providing
Increased recovery
Greater resource value
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