Evalucación de molino de bolas

7/30/2019 Evalucacin 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


4/26

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

Date post:	04-Apr-2018
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