a perspective on modelling and simulation … perspective on modelling and simulation engineering...
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A perspective on modelling and simulation
engineering
A perspective on modelling and simulation
engineering
Claudio L. SchneiderClaudio L. Schneider
Coordinator of Mineral Processing - CETEM
Ore body
Mapping
Basic design strategy for
processing plants
Characterization Modeling Scale up Engineering
Unit ops Plant design ResultsOreOre body
Associations
Texture
Mineralogy
Morphology
Drilling
Unit ops Plant design ResultsOre
Simple tests for variability
Complete testing for reference sample scale up
Simulations with parameters obtained from reference sample
Efficiency
Yield
Quality
Investments
Cash Flow
Profit
CAPEX/OPEX
Scale up safety factors
Large volume samples
Variability (geometallurgy)
Processing route
Pilot scale tests
A processing plant at Gaudin’s
time (or thereabouts)
A processing plant at Gaudin’s
time (or thereabouts)
• Units were small. Plants would have several lines of crushing,
grinding and flotation equipment if capacity were to be large.
• The plant would have many sampling points and a laboratory for
routine chemical analysis (sustainability!).
• Crusher and ball mill design would have been made with aid from
Allis Chalmers. CWI and BWI were the basis for conceptual design
and scale-up.
A processing plant at Gaudin’s
time (or thereabouts)
• Flotation conceptual design would be based on batch flotation tests
(Denver cells) and locked-cycle tests.
• Grinding size would have been determined from flotation tests.
• Mineralogy would have been used to qualify concentration
performance. The engineer new there were going to be losses on
coarse unliberated particles that recirculated back to the rougher
cell.
• The regrind circuit would have been the novelty at the time.
(Gaudin?)
A processing plant at Gaudin’s
time (or thereabouts)
• At design time pilot tests were carried out extensively. (certainty)
• At operating time, the discussion would have been this: Is the
regrind circuit working as expected? (Cases of Vale Sossego and
Freeport Indonesia)
• Ball milling is responsible for about 50% of the operating costs.
A modern version of the
processing plant
A modern version of the
processing plant
• Several lines of small units have been replaced by large units and a
single line. CAPEX is reduced. (Kennecott Copperton plant, 1980s)
• The crushing stages and the rod mill were replaced by a large SAG
mill. Major CAPEX gain.
• Fine production in the SAG allows for a smaller grinding circuit
(CAPEX and OPEX reduction)
• VertiMill replaces the ball mill. 25% reduction on energy demand.
A modern version of the
processing plant
• Several lines of small units have been replaced by large units and a
single line. CAPEX is reduced. (Kennecott Copperton plant, 1980s)
• The crushing stages and the rod mill were replaced by a large SAG
mill. Major CAPEX gain.
• Fine production in the SAG allows for a smaller grinding circuit
(CAPEX and OPEX reduction)
• VertiMill replaces the ball mill. 25% reduction on energy demand.
A modern version of the
processing plant
• The regrind circuit is now based on the ISAMill. Finer grinding with
similar energy requirements. Improvement in recovery.
• Column flotation is more efficient in recovering fine particles.
• The ore is tougher, more difficult to liberate and the grade is smaller.
(This is going to get worse, innovation is needed!
A modern version of the
processing plant with HPGR
A modern version of the
processing plant with HPGR
• Secondary crushing is back. (but larger HPGRs are being made)
• Fine generation in the HPGR may reduce ball milling requirements
by 40 % (Cerro Verde reports 20%).
The modern approach for design
• Simulation can be used for processing route evaluation during
conceptual design.
• Usually reduction of OPEX is favored during conceptual desing
while CAPEX is favored during engineering. Are we doing this
right?
• Scale-up technology is available for SAG, HPGR, Ball Mill, VertiMill,• Scale-up technology is available for SAG, HPGR, Ball Mill, VertiMill,
IsaMill and crushers. All comminution operations in a large
processing plant can be scaled-up from bench scale tests, except
for the SAG mill. This is the tendency for the future.
• Automated mineralogy can show us what is really happening in the
plant.
• The regrind circuit now functions according to Gaudin’s design.
Liberation spectra measured on
iron ore (NSPC Steel)
Liberation spectra measured on
iron ore (NSPC Steel)
Automated mineralogy systems
can characterize flotation kinetics
60
70
80
90
100
Ult
ima
te r
eco
ve
ry,
%
212x150
0
10
20
30
40
50
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00
Ult
ima
te r
eco
ve
ry,
%
Average particle grade, %
212x150
150x106
106x75
75x53
53x38
Variability and Geometallurgy have
become a reality when designing a
new plant. (sustainability!)
70%
80%
90%
100%
Cu
mu
lati
ve d
istr
ibu
tio
n,
%
0%
10%
20%
30%
40%
50%
60%
70%
0 5 10 15 20 25 30
Cu
mu
lati
ve d
istr
ibu
tio
n,
%
BWI, kWh/t
Concentration
Processing
Comminution operations
Surface area Exposure Liberation
Concentration processes have natural limitations and
restrictions
even when
liberation is
complete
Leaching applications (and other processes) may be controlled by surface kinetics at one or another stage
Leaching solutions must reach phase of interest and exposure is a fundamental requirement For leaching
applications, liberation and exposure are intimately connected
Required for most mineral processing operations
Bed packing and permeability
Processing
Comminution operations
Surface area Exposure Liberation
• CLP – Confined bed compression• CLP – Confined bed compression
• DWT – Drop Weight Test
• BWI – Ball Work Index
• RWI – Rod Work Index
• CWI – Crusher Work Index
•AI – Abrasion Index
• H-F – Herbst-Fuesternau Batch grinding test
• LABWAL – HPGR testing
• Continuous grinding tests
Comminution operations
Exposure
Liberation
Feed particles
Fixed rollMoving RollOil cylinders
Nitrogen
Cylinders
High pressure grinding rolls: new efficient grinding technology
Product
Comminution operations
LABWAL
Efficient crushing/grinding
Alternative.Alternative.
Comminution operations
DWT
Axb
Crusher ParametersCrusher Parameters
CWI
SAG Milling Parameters
Comminution operations
Grinding Lab
AI
H-FH-F
WI
Comminution operations
Crushing Plant
Pilot scale,
large volumelarge volume
Concentration operations
Flotation
Mini Pilot
Plant, product Plant, product
assessment
Concentration operations
Flotation
2”column
6”column6”column
Concentration operations
Gravity
Jig
SpiralSpiral
Shaking tables
Concentration operations
Magnetic
WHIMS
DrumDrum
RE Drum
Pressure filters
Preparation operations
Large patio for
sample
Handling
sample
receiving ,
preparation
Characterization
Laboratory
• Atomic Force Microscope
• Zeta Sizer
• Tensiometer
• BET
• Goniometer• Goniometer
• FTIR
• Helium Picnometer
• Bubble sizer
• Rheometer
• Leaf Test
• Batch Sedimentation Test
Simulation/model development
Software
ModSim plant-wideModSim plant-wide
simulator