size reduction operations from 8 minoocad@jah …file/jah_mine_to_mill_simulation.pdf · size...
TRANSCRIPT
Dynamic Simulation ofSize Reduction Operations from
Mine-to-Mill
byJ.A. Herbst and W.T. Pate
J.A. H
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Outline
✦ Introduction✦ A General Flowsheet
Simulator✦ Comminution Objects✦ Simulation Case Study✦ Future Capabilities✦ Conclusions
Kona
HawaiiMauiMolokai
Oahu
Kauai
Honolulu
Tahiti
California Mexico
Hilo
J.A. Herbst & Associates
Australia
The Cost of ComminutionWorldwide
Energy Consumed Worldwide≅≅≅≅ 2.6 x 1010 US$/year
Wear Parts Consumed Worldwide= 5 billion US$/year
100%100%
00Product Size
Ener
gy E
ffici
ency
50%50%
Typical Breakdown ofComminution Costs
Explosive Fracturing 1%
Coarse Crushing 2%
Fine Crushing 20%
Grinding 77%
Mine-to-Mill Simulation
Real World Model Object FlowsheetSimulator
Benefits ofObject Oriented Programming
A software object contains code and data which simulate thepertinent characteristics of a physical device or stream
PROGRAM MAINCALL MINE ( )CALL TRUCK ( )CALL CRUSH(FEED,CRUSHPROD)CALL STORAGE ( ) CALL SCREEN(FEED,SCREENPROD)CALL MILL(FEED,MILLPROD)SUBROUTINE MINE ( )SUBROUTINE TRUCK ( )SUBROUTINE MILL(FEED,MILLPROD)SUBROUTINE STORAGE ( )SUBROUTINE CRUSH(FEED,CRUSHPROD)SUBROUTINE SCREEN(FEED,SCREENPROD)
Object Oriented Traditional
When process objects are connected by streams they are linked for computation
Conceptual Design of MinOOcad
ProcessObject
ObjectProperties
ObjectDisplay
StreamObject
StreamObject
( )ttO ∆+2
( )ttO ∆+1
( )tI
Object Menu
ContainerStream
Object #1
StreamObject #M
ProcessObject #2
ProcessObject #N
ProcessObject #1
ProcessObject #3
Implementation ofMinOOcad
Models of Flowsheet Elements
SLOW
FAST
INTERMEDIATE
0 1 10
Response
t/ττττ Longest Dwell Time
Coarse OreStorage
Dynamic/Multi-Components
Accumulation = Input - Output+ Generation
ScreenStream
ε
P80
T
P
( )dt MOut,ij f Mij= - + ’sdMi,j MIn,i,j
• •
Particle Size Decreasing
ABAB
BB
AA
Comminution Objects- The Ball Mill
Feature 1Visualization
Feature 2Dynamic
PerformanceControl
Feature 3Scale-up/Design
Feature 4Capital/
Operating Cost
$$
ManagerComputationProcedures
Input and Output User Interface
KnowledgeBase
Ball Mill Object
Comminution Objects
MineTruckStorageCrushersConveyorsScreensBall Mill - Pebble MillSAG - AG MillsSumpsHydrocyclones
Simulation Case Study
MinePrimaryCrusher
PrimaryMills
SecondaryMills
BallMill
Coarse OreStorage
SAGMILL
SAGMILL
MinOOcad Flowsheet
Tool Bar and Property Page
Property Pages
Zoom on Property Page
Outputs
Date Time, hr Feedrate Feed waterJetwater Mill rpm6/14/98 18:00 0.00000 2037.9 673.3 75.0 10.016/14/98 18:02 0.03333 2010.7 672.4 75.0 10.016/14/98 18:04 0.06667 2021.5 673.0 74.9 10.016/14/98 18:06 0.10000 2051.2 673.6 74.9 10.016/14/98 18:08 0.13333 2080.9 677.6 74.9 10.016/14/98 18:10 0.16667 2059.8 690.0 74.9 10.016/14/98 18:12 0.20000 2076.0 687.8 74.9 10.016/14/98 18:14 0.23333 2096.1 682.5 74.8 10.016/14/98 18:16 0.26667 2116.2 678.1 74.8 10.016/14/98 18:18 0.30000 2112.2 679.5 74.8 10.016/14/98 18:20 0.33333 2099.1 675.8 74.8 10.016/14/98 18:22 0.36667 2095.3 675.5 74.8 10.016/14/98 18:24 0.40000 2093.0 665.2 74.7 10.016/14/98 18:26 0.43333 2090.6 665.4 74.7 10.016/14/98 18:28 0.46667 1507.2 666.8 74.7 10.016/14/98 18:30 0.50000 1663.9 684.5 74.7 10.01
Spreadsheet Graphic
Base Case - At Steady State
SAG Mill %L=12
Ball Mill %L=70
0.01
0.10
1.00
10 100 1000 10000 100000 1000000
Particle Size, microns
Frac
tion
Pass
ing Mine
% L =0
Gyratory% L=0
PredictedOperating Data
Dynamic SituationsSimulated
✦ Increase in Powder Factor at Mine
✦ Increase in Truck Haul Time
✦ Decrease in Stockpile Inventory
Increase in Powder Factor
10000
100000
1000000
0 2 4 6 8 10 12
Time, hr
Min
e, C
rush
er a
nd S
tock
pile
P80
, m
icro
ns
10
100
1000
SA
G a
nd B
all M
ill P
80,
mic
rons
SAG Mill
Ball M ill
M ine
Stockpile
Crusher
Powder factor increased by 150%
SAG Mill
Ball Mill
Mine
Stockpile
Crusher
Increase in Truck Haul Time
0
200
400
600
800
1000
0 2 4 6 8 10 12 14
Time, hr
Tonn
age,
tph
0
10
20
30
40
50
60
70
80
Mag
netit
e Li
bera
tion,
%H
aul T
ime,
min
.
Truck haul time increased by 25%
Truck tonnage
SAG mill tonnage
Ball mill magnetite liberation
Stockpile tonnage
Truck haul time
SAG Mill Tonnage
Ball Mill Magnetite Liberation
Stockpile Tonnage
Truck Haul Time
Truck Haul Time Increased by 25%
Decrease in Stockpile Inventory
10
100
1000
10000
100000
1000000
2 4 6 8
Time, hr
P80
, m
icro
ns
100
200
300
400
500
Tonn
age,
mtp
h
M ine P80
Crusher P80
SAG mill tph
Stockpile tph
Ball mill P80
SAG mill P80
Ball Mill P80
SAG Mill P80
Stockpile tphSAG Mill
tph
Mine P80Crusher P80
Downstream Impacts
0
200
400
600
800
1000
2 4 6 8
Time, hr
Hol
dup,
t o
r To
nang
e, tp
h
0
1000
2000
3000
4000
5000
Pow
er, k
w
S tockpile tonnage
SAG mill power
SAG mill rock tons
SAG mill tonnage
Begin stockpile inventory change
50
75
100
125
150
175
2 4 6 8Time, hr
P80
, m
icro
ns
22
24
26
28
30
32
% o
f Mag
netit
e Li
bera
ted
Begin change in stockpileinventory
Ball mill P80
Ball mill magnetite liberated
Future Possibilities✦ Operating costs calculated on a minute-to-minute
basis over the entire flowsheet✦ Enterprise-wide control system capability integrated
into simulator✦ Incorporating the impact of maintenance using
realistic wear and replacement models✦ Embedding into control system software for on-line
decision making
Conclusions✦ Comminution comprises the most energy intensive and
costly set of unit operations at a mine/mill site.✦ Opportunities exist to improve "enterprise-wide financial
performance" through understanding and exploitingdynamic/steady state interactions between comminutionoperations.
✦ A Windows based generic flowsheet simulator,MinOOcad, has been developed to allow dynamicsimulation for any number of elements
✦ Advanced comminution models embedded in welldesigned software objects can provide realistic simulationsoff all flowsheet elements.
✦ Potential uses for MinOOcad are broad and exciting.