optimise comminution with shovel-based fragmentation analysis · modelling and simulation - 3...
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Optimise Comminutionwith Shovel-based
Fragmentation Analysis
Tucson, USA; Chile; South Africa; Australia
www.spliteng.com
Explore for minerals
Develop Mine
Blast, crush then grind rocks
to liberate minerals
(Comminution)
Extract minerals
then smelt to metals
Mining 101
Comminution Chain: Blasting is the lowest cost per ton stage
Effective blast design optimises
fragmentation from muck pile through digging,
loading, crushing and grinding to
improve productivity and mine site profits
Blast Dig, Load Crush Grind
MEASUREFragmentation to…
MANAGEEnergy input
Design blast for optimum fragmentation
•Compare predicted fragmentation with measured
•Modify blast design for optimum fragmentation
Optimum fragmentation
•Reduce mine site costs to increase profit:
• Control quantity of fines
• Increase digability and truck load factors
•Avoid oversize rocks which block crusher
Blast Fragmentation
Coarse Fine
Optimum Fragmentation
Not too coarse not too fine
just right !! Fines:
• Increase digability and truck load factors
• Impact SAG mill throughput more than ore hardness
or
• For iron ore, control lump to fines ratio
at
Split Engineering: image analysis output
at
BLAST DESIGN
Rock Characterisation –Structure and Strength
Rock Mass - Blast Interaction
Tensile or Coarse
fragmentation zone• Dominated by rock
characterisation
• Source of oversize
which blocks crusher
Drill hole
Compressive or
Crushing zone• responsible for fines
Modelling and Simulation - 3 Technology Tools
ROM
Mining fragmentationmodel
Rock characterisation
PRODUCTION BLASTSIZE DISTRIBUTION
BALL
MILL
PEBBLE
CRUSHERCYCLONES
SAG
MILL
PRIMARY
CRUSHER
1 10 100 1000
100
80
60
40
20
0
Particle Size (mm)
JKMRC Blast Fragmentation Model
Blast Design
Multi-discipline iterative process:• Rock structure and geotechnical data
• Bench height
• Blast hole diameter
• Explosive type
• Hole pattern, explosive quantity and location (stemming)
• Detonation sequences
• Production tonnage
• Shovel (or loader) and truck size
• Downstream process requirements
Measure blast fragmentation to Managemodel, simulate and predict PSD of blast
for input to process simulation
Optimising Fragmentation
ROCK SAMPLES
1 10 100 1000
100
80
60
40
20
0
CHARACTERISE
SIMULATE PLANT
DESIRED
RESULT ?
BLAST DESIGN
CHARACTERISE
ROCK MASS
IMPLEMENT
YES
NO
ADJUST
VARIABLES
ROM Size
VALIDATE
Simulate
Comminution
Blasting
Target ROM Fragmentation
50
1 10 100 10000
100
Pe
rce
nt
pa
ss
ing
Size mm
Explosion
fractures
Liberation of
in-situ blocks
Increase
fines
Decrease top size
Combination
MEASUREto
MANAGE FRAGMENTATION
Measure Off-Line
OR: Measure On-Line with image analysis
Options for On-Line Measure
ShovelCam
20
• Real-time measure
of PSD link to GPS
• Add quality to drill
and blast tons
• Detect oversize
rocks and send to
secondary breakage
ShovelCam
21
TruckCam
22
• Feed-back to mine on
measured blast
fragmentation
• Feed-forward to plant on
product from the mine
• Correlate PSD from
mine to performance of
downstream operations
OPTIMISE FRAGMENTATION
TO IMPROVE PRODUCTIVITY
Business Case
• Increase digability and truck fill factors
• Avoid oversize blocking primary crusher• 1 hour downtime pay for ShovelCam capex
• Feedback to Blast Engineers • Optimise PSD for downstream operations• Increase SAG mill throughput• Increase lump to fines ratio
Increase productivity and mine site profits
Fragmentation vs Load and Haul Productivity
• X Gold Mine studied relationship between fragmentation and digging
• Finer fragmentation gave:•35 % decrease in dig time,
•9 % decrease in truck loading time
•12 % increase in truck payload
•19 % increase in loading performance
• 8% decrease in load and haul cost
Increase in fines:
•Increased excavator productivity throughincrease in muckpile digability and increase in bucket and truck fill factors
•Reduced stockpile segregation
•Reduced energy consumption for crushing and grinding
•Gave 15% increase in SAG mill throughput
Continuous improvement of blast design at YYY Gold Mine
Morenci Blast Improvement
P80 Contour
Drill Pattern
(feet)
P80
(inches)
Top-size
(inches)
Shovel
tons per day
30 x 30 27 50 30,000
27 x 27 16 33 70,000
•Contract miner has targets for top size and
P80 of shot rock
•TruckCam measures PSD of ore delivered
to crusher:
•Oversize attracts penalties
•Ore within specification attracts bonuses
African Zinc Mine
Cadia SAG Mill Throughput 1800 to 2300 tph
Hart 2001
Mine-to-Mill Case Studies
Mine Site Mine Country Product Increase
Batu Hiju Cu Indonesia 10 to 15%
Antamina Cu Peru 45 to 60%
Los Bronces Cu Chile 15 to 20%
Cerro Corona Au Peru 15% hard ore, 6% overall
Phu Kham Cu Laos 8%
Ahafo Au Ghana 8%
Morila Au Mali 10%
Oyo Tolgoi Cu Mongolia 25%
Iduapriem Au Ghana 21 to 32%
Conclusions
•Energy efficient comminution high on Back to Basics agenda of all mining companies
•Optimisation of fragmentation requires effective measure to manage blast design
•Optimised fragmentation increases productivity and mine site profits
• Innovative technologies for success are readily available and include:
•ShovelCam and TruckCam
Split Engineering since 1997
Split-Online
• 693 cameras installed at 134 mine sites
• 508 Split-Online above conveyors
• 102 Split-ShovelCams
• 83 Split-TruckCams
Split Desktop
• 250 licenses
Split Engineering
MEASURE fragmentation
for you to
MANAGE fragmentation
and IMPROVE productivity
at your mine site
www.spliteng.com