Evalucación de molino de bolas
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Transcript of Evalucación de molino de bolas
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TitleTitle
No.1 Milling Unit Grind Optimisation
Jan Matuwane
27 May 2005
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AgendaAgenda
Introduction
Sampling procedure
Sample points
Simulations
Results and Conclusions
Recommendations
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ObjectiveObjective
Improve Mill grind:
Mill Discharge Density Optimization
Circulating load
Grinding Performance
Mill power
Ball size ratio Evaluating cyclone performance by
using 100 &150 mm Spigots
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Ball Mill circuit
Mill variables
Feed size Power consumption
Grind
Ball charge volume
IntroductionIntroduction
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SAG Mill Ball Mill
Cyclone Feed
U/F
O/F
Mill Sump
No.1 ClusterLinear Screen
Fresh FeedDilution
U/F U/F
Scats
Dilution
M1 conveyor
Stockpile
VSD Pump
Milling CircuitMilling Circuit
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Milling CircuitMilling Circuit
SAG Mill Ball Mill
Cyclone Feed
U/F
O/F
Mill Sump
No.1 Cluster
Linear Screen
Fresh FeedDilution
U/F U/FScats
Dilution
M1 conveyor
Stockpile
VSD Pump
Sampling Points
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Data to be collectedData to be collected
Ball Mill inlet dilution water flow rate
Ball Mill Power Consumption (kW)
Cyclone pressures (kPa)
Cyclone feed pump output (%)
Cyclone feed density
Cyclone feed flow rate (m3/h)
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15%15%Ball Filling
0.770.22Circulating ratio10.145.13Kwh/t +150 micron
12.7030.28Kwh/t -75 micron
66.0679.57P80 (micron)474679F80 (micron)
0.330.26Mill discharge w/s
75.0681.04% solids
3.719.42Wi (kWh/t)
18051970Power drawn (kW)
150 mm
Spigots
100 mm
Spigots
Test ResultsTest Results
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22%22%Ball Filling
0.770.22Circulating ratio
10.145.13Kwh/t +150 micron
12.7030.28Kwh/t -75 micron
66.0679.57P80 (micron)
474679F80 (micron)
0.330.26Mill discharge w/s
72.0077.08% solids
4.8911.16Wi (kWh/t)
26402705Power drawn (kW)
150 mm
Spigots
100 mm
Spigots
Test ResultsTest Results
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Discharge Particle Distribution
0
20
40
60
80
100
120
10 100 1000 10000
%P
assing
100 mm 150 mm
Mill Discharge Size DistributionMill Discharge Size Distribution
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Mill Discharge Vs % -75 Passing
50
55
60
65
70
75
80
85
90
70.00 72.00 74.00 76.00 78.00 80.00 82.00 84.00 86.00 88.00 90.00
MIll Discharge % Solids
%
-75Passing
100 mm 150 mm
`
Mill PerformanceMill Performance
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Cyclone Perfomance Vs Predicted Tromp curve
150 mm - sampling data
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1 10 100 1000 10000 100000
Particle Size, microns
Partition
facto
r
Simulation 150 mm
Tromp Curves (2)Tromp Curves (2)
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Cyclone Perfomance Vs Predicted Tromp curve
100 mm - sampling data
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1 10 100 1000 10000 100000
Particle Size, microns
Partition
facto
r
Simulation 100 mm
Tromp Curves (1)Tromp Curves (1)
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55.746.745.3859.81Feed % Solids
0.270.450.420.18Alpha Water
1291029585D50 Corrected(um)
526369550238Circulating load
0.220.250.210.18Imperfection
150 mm
Spigots
100 mm
Spigots
150 mm
Spigots
100 mm
Spigots
SimulationPlant data
Cyclone Performance
Cyclone performanceCyclone performance
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379F80(micron)35.0Lift Angle, ()
1.82Reduction Ratio15.0Balls Filling, %
3.74Sp. Energy, KWH/ton35.0Charge Level, %
74.0% Solids (by weight)3.99App. Density, ton/m3
806.8Throughput, ton/hr72.0Speed, % Cr itical
2068Mill Power, kW (Net)30.0Length, ft
2298Mill Power, kW (Gross)16.0Diameter, ft
BALL MILL PERFORMANCE
Base Case ExampleRemarks :
Grinding Circuit Mass Balance Estimator
BALLBAL
100 mmSample
NMoly-Cop ToolsT M
Mill performance SimulationMill performance Simulation
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501F80(micron)35.0Lift Angle, ()
1.19Reduction Ratio22.0Balls Filling, %
0.39Sp. Energy, KWH/ton35.0Charge Level, %
71.3% Solids (by weight)4.08App. Density, ton/m3
7780Throughput, ton/hr72.0Speed, % Cr itical
2702Mill Power, kW (Net)30.0Length, ft
3002
Mill Power, kW
(Gross)16.0Diameter, ft
BALL MILL PERFORMANCE
Base Case ExampleRemarks :
Grinding Circuit Mass Balance Estimator
BALLBAL
150 mm
Sample
NMoly-Cop ToolsT M
Mill performance SimulationMill performance Simulation
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Charge Volume vs x
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 200 400 600 800 1000 1200 1400 1600
x (mm)
Cha
rgeVolume(%
)
Ball Mill
First run
Kw = 1987
Second run
Kw = 2300
Charge Level EstimationCharge Level Estimation
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Mill Power UtilizationMill Power Utilization
%-75um (O/F) Vs Power draw (kWh/t)
0
10
20
30
40
50
60
70
80
90
100
Jul-04
Jul-04
A
ug-04
A
ug-04
A
ug-04
A
ug-04
S
ep-04
S
ep-04
S
ep-04
S
ep-04
O
ct-04
O
ct-04
O
ct-04
O
ct-04
O
ct-04
N
ov-04
N
ov-04
N
ov-04
N
ov-04
D
ec-04
D
ec-04
D
ec-04
D
ec-04
Jan-05
Jan-05
Jan-05
Jan-05
Jan-05
%-
75um
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
Power(kWh
/t)
%-75 um Pow er draw (kWh/t) Linear (Pow er draw (kWh/t))
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50/80 mm ratio Ball Addition50/80 mm ratio Ball Addition
Ineffective reduction of +150m fractionin Ball mill
Simulation indicated larger dia ballrequired for coarser material
Intent to mill both fractions
80 mm added 50/50 ratio with 50 mm(Trial and Error)
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Grind theoryGrind theory
D is in t e g r a t e
5 0 m m
8 0 m m
C o a r s eF i n e
BallWearRate
B a l l S iz e
D is in t e g r a t e
5 0 m m8 0 m m
C o a r s eF in e
BallWearRate
1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0
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Grind Vs ResidueGrind Vs Residue
% +150 Um Vs Plant Residue
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
Jul-04
Jul-04
Aug-04
Aug-04
Aug-04
Aug-04
Sep-04
Sep-04
Sep-04
Sep-04
O
ct-04
O
ct-04
O
ct-04
O
ct-04
O
ct-04
Nov-04
Nov-04
Nov-04
Nov-04
Dec-04
Dec-04
Dec-04
Dec-04
Jan-05
Jan-05
Jan-05
Jan-05
Jan-05
%
+150
um
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Residue
(g/t)
% +150um Residue (g/t) Linear (% +150um)
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Tons milledTons milled
TONS MILLED
0
50,000
100,000
150,000
200,000
250,000
300,000
Jun-0
3
Jul-0
3
Aug-03
Sep-03
Oct-0
3
Nov-0
3
Dec-0
3
Jan-0
4
Feb-0
4
Mar-0
4
Apr-04
May-0
4
Jun-0
4
Jul-0
4
Aug-04
Sep-04
Oct-0
4
Nov-0
4
Dec-0
4
Jan-0
5
Feb-0
5
Mar-0
5
Apr-05
Q4200
4
Q1200
5
Q2200
5
Q3200
5
YTD
TON
S
Tons Milled Plan
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RecoveryRecovery
RECOVERY
92
94
96
98
100
Jun-03
Jul-03
Aug-03
Sep-03
O
ct-03
Nov-03
Dec-03
Jan-04
Feb-04
M
ar-04
Apr-04
M
ay-04
Jun-04
Jul-04
Aug-04
Sep-04
O
ct-04
Nov-04
Dec-04
Jan-05
Feb-05
M
ar-05
Apr-05
Q
4
2004
Q
1
2005
Q
2
2005
Q
3
2005
YTD
%
Recovery Plan
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Feasibility StudyFeasibility Study
1,477,046RThus profit @ 1.00 kg/t addition (Including make up)
2,465,000RExtra revenue achieved
85,000R/kgGold price
29.00kgExtra Au extracted
1,167.00kgGold Produced @ 96.4 % Recovery after make up
1,138.00kgGold Produced @ 94 % Recovery before make up
5.42g/tHead Grade
888,529RSteel cost/month @ 1.00 kg/t
99,425RCost of steel make up
25tonsAmount of steel used for make up
3977R/tSteel ball cost for make up
3977R/tSteel ball cost
223.417tons1.00Steel addition @ 1.0 kg/t223417tonsForecasted tons milled per month
223417tonsCurrent tons milled
MonthlyBase data
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Maintain Optimum Mill Discharge
Research Mill Feed Variation
Investigate Liner Wear Screen failure
due to over-charge
Continue 50/80 mm steel ball blending
Different ratio ( 100% 80 mm)
RecommendationsRecommendations
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Thank you