Transcript (EEO) workshop presentation: Perth September 2011 - CEEC

Coalition for Eco-Efficient Comminution
Vision
To accelerate implementation of eco-efficient
comminution strategies through promotion of
research, data and industry benefits
Patron
Owen Hegarty G-Resources Group
Board
Chair
Director
Director
Director
Director
Elizabeth Lewis-Gray Gekko Systems
Prof Tim Napier-Munn JKMRC
Dr Wayne Stange AMIRA
Dr Mike Daniel CMD Consulting
Dr Zeljka Pokrajcic Worley Parsons
CEEC Sponsors
Comminution Energy Consumption
4 – 9% Australia’s electricity
consumption
30 – 40% total mine
Source: CSRP Eco-Efficient Liberation – Outcomes and Benefits 2003-2010
Comminution Energy Consumption
CO2 contributions for the stages of copper concentrate production, Source: Norgate and Haque, 2010
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Lo
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Typical site comminution energy footprint
1999 Leinster Nickel Operations CO2 Emissions
40,000
Sulphur
35,000
Kerosene
30,000
Coke
LPG
25,000
Petrol
20,000
Diesel
15,000
Electricity
10,000
Natural
Gas
5,000
0
Source Le Nause, Temos 1992
Eco Efficient strategies
• Understand mineral and gangue
liberation characteristics
• Reject gangue or recover mineral
in crushing step, prior to milling
• Recover mineral or gangue at
coarsest particle size
• More crushing less grinding
• Utilise new and more energy
efficient technologies
Energy & grind size
Selection of the coarsest possible grind size
1.E+05
Energy (kWh/t)
1.E+04
1.E+03
1.E+02
1.E+01
1.E+00
1.E-01
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
Particle Size (micron)
Source: Hukki RT, 1961
1.0E+04
Optimum liberation
Coarser grind may improve recovery
More crushing – less grinding
• Ball mills only apply 5%
of energy used to
particle size reduction
• Fine crushing is more
energy efficient
• Very low power
consumed in supporting
systems such as
pumping and conveyors
“The most efficient way
to break rock, is not to
break rock at all”
Dr Rob Morrison, JKMRC
Improved ore presentation and flow sheets
• Blasting
– Optimise fragmentation to maximise
fines in ROM ore
– “Bricks and mortar”
• Screening:
– ahead of, and in, the grinding circuit
• Gangue Rejection
• Pre-concentration
• Concentration
Improving technologies
• Fine crushing
– VSI
– HPGR
• Fine Screening
• Ore Sorting
• Gravity – continuous & batch
– InLine Pressure Jig
– Centrifugal Concentrators
• Coarse Flotation
Castlemaine Goldfields plant
New flowsheet with gangue rejection
WITH
Unit: CONVENTIONAL PRECONC. Change:
Material Treated:
Grade:Au
Contained Au:
Gangue Rejection:
Process Plant Feed:
Production:
Process Plant Recovery:
Overall Recovery:
Mt
g/t
oz
Mt
g/t
oz
Mt
g/t
oz
oz
MW
Energy Efficiency for gold produced MWhr/oz
Energy Efficiency for ore treated:
kWhr/t
Average Processing Power Demand:
21
0.82
554,000
21
0.82
554,000
415,000
74.9%
74.9%
68
1.44
28.5
21
0.82
554,000
10
0.13
41,150
11
1.45
512,850
435,900
85.0%
78.7%
50
1.01
20.9
5%
-27%
30%
27%
• Recovery increased by maximising gravity recovery, finer
grind, increased head grade to process plant.
Benefits of New Process for site
•
•
•
•
•
Lower Capital Cost for Greenfields Installation
Net reduction in energy consumption
Increased gold recovery
Increased gold production
Reduced $/oz operating cost of gold produced
CEEC Linked In discussion page
CEEC Linked In Discussions
•
•
•
•
•
Ore sorting
Microwave technology
Blasting techniques
Comminution research
Conference blogs
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End