Antamina’s Mine to Mill Throughput

Improvement

Ed Rybinski

November 2012

http://www.antamina.com

Based on Paper “Optimization and Continuous

Improvement of Antamina Comminution Circuit” presented

originally at SAG 2011 in Vancouver, Canada.

2

Agenda

1. Antamina Overview

2. Objective “Mine to Mill”

3. Why Mine to Mill

4. What was Done

5. Changes to the Process

6. Results

7. Other KPIs

8. Summary and Conclusion

9. Acknowledgements

1. Antamina Overview

1. BHP, Xstrata, Teck Resources and Mitsubishi

2. Mine: 270 km NE of Lima, Peru

3. Pipeline: 302 km

4. Port: 300 km NW of Lima

5. Resource (MII): 1.8Bt

6. Head Grade: 0.84%Cu, 0.53%Zn

7. Mine (630ktpd):

a. 4 Bucyrus, 2 P&H shovels

b. 77 CAT 793

c. 15 Komatsu 930E

8. Concentrator (130ktpd)

a. 2 SAG (38‘x19‘, 20MW)

b. 4 BM (24‘ x 35.5‘,11MW)

3

4

2. Objective of Mine to Mill Project

1. Increase the SAG Mill Throughput

2. Focus on “Harder” CuZn Ores

3. Budget Throughput 2007:

• CuMo ores: 4,120 tph

• CuZn ores: 2,705 tph

4. Energy Consumption

• CuMo ores: 2.8 kWh/t

• CuZn ores: 5.0 kWh/t

5. Review Operations from “Mine to Mill”

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3. Why “Mine to Mill”

1. Mine Optimizes their Process

2. Concentrator Optimizes their Process

3. Need to Look at the Big Picture – Geology, Drill/Blast, Loading, Hauling, Crushing, Grinding

PROCESS EFFICEINCY AUTHOR

Blast 20% Brinkman(1987)

Grind 1%

Willis(1988)

Hukki(1975)

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4. What was Done (with Metso)

1. Collect Data

– Geology, drilling, blasting, crushing and grinding

2. Audit of Current Practices

– Drilling, blasting, crushing and grinding

– Complete crusher and mill circuit surveys (January 2007 and

December 2008)

3. Modelling of Process

– Blasting, Crushing and Grinding

4. Recommendations/Implementation/Analysis

7

Audit Current Practice (Drill/Blast)

8

Review Fragmentation and Hardness

9

Mill Survey

10

Blast Tags

DETECTOR

DETECTOR

[ID,x,y,z]

[ID, time]

RECEPTOR

POST BLAST

POST CRUSHER

SAG1 MILL FEED

[ID, time)

11

Modeling Blasting, Crushing and Grinding

12

5. Changes to Process (Drill/Blast)

Blast Design Pre MtM(2006) Post MtM(2007) New Designs (2008)

Bench height m 15 15 15

Burden m 7 6 5.5

Spacing m 8 7.5 6.5

Hole diameter mm 311 311 311

Stemming length m 7 7 7

Subdrill m 2 2 2

Explosive Weight kg 988 988 988

Explosive Type HA64 HA64 HA64

Initiation Type Pyro-technic Pyro-technic Electronic

Powder Factor kg/t 0.35 0.43 0.54

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Changes to Process (Concentrator)

1. Increased Pulp Lifter Capacity (1Q 2007)

– Focused on reducing slurry pooling in CuMo ores

– Pulp Lifters Depth Increase from 250 to 350 mm

– Other 38 ft SAGs operate with 375-600 mm pulp lifters

2. Install Pebble Crusher Plant (May 2008)

– Focus on Harder/Coarser CuZn ores

– 2 x 500kW crushers

3. Install SAG Bypass (1Q 2009)

– Designed to be used during replacement of SAG stator

– 1 x 600kW crusher

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6. Results: Increase in Fines

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.01 0.1 1 10 100 1000

Cu

m %

Pas

s (µ

m)

Particle Size (mm)

SAG Feed Particle Size Analysis (Pre and Post Mine to Mill)

CuZn 15/01/07

CuZn 28/09/11

Increase in Fines

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Results (Theoretical Improvement)

CuZn

15%11% 4%

16%16%

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Base Case, PF=0.35kg/t,

Axb=84

Inc PF 1, PF=0.43kg/t

Pebble Crusher,

Pulp Lifters

Ball Charge Inc PF 2, PF=0.54kg/t

Ore Hardness, Axb=174

SAG

Th

rou

ghp

ut (T

PH

)

Modifications

SAG Mill Throughput Improvements

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Results (Actual Improvement)

2000

2500

3000

3500

4000

4500

5000

2006 2007 2008 2009 2010 2011

SAG

TP

H

Year

SAG TPH Improvements

CuZn CuMo

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7. Other Key Process Indicators (KPIs)

1. Dilution

2. Wall Damage and Spillage over Crest

3. Fly Rock

Reconciliation Mine vs Concentrator

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

2005 2006 2007 2008 2009 2010 2011

Year

Rati

o C

on

cen

tra

tor

vs M

ine

Cu Grade (%) Zn Grade (%)

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8. Summary and Conclusion 1

1. Started Mine to Mill in 2007

• Modeled Entire Process, Focused on Drill/Blast

• Increased Powder Factor by 55%

• Controlled Secondary Metrics (dilution, wall damage, fly rock)

2. Antamina Implemented Pebble Crushing, Pulp Lifter

3. Mother Nature Made Rock Softer

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Summary and Conclusion 2

SAG TPH

Ore Type 2005/2006 2011 % Increase

CuMo 4,078 4,769 17%

CuZn 2,788 4,373 57%

Difference 46% 9% -

SAG kWh/t

Ore Type 2005/2006 2010/2011 % Decrease

CuMo 2.9 2.6 11%

CuZn 5.0 3.0 40%

Difference 43% 15% -

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1. To Compañía Minera Antamina for permission to present at

PROCEMIN 2012.

2. To Jorge Ghersi, Frank Davila and Javier Linares of Compañía

Minera Antamina and Walter Valery, Alex Jankovic, Roberto Valle

and Serkan Dikmen of Metso Process Technology and Innovation,

Co-authors of “Optimization and Continuous Improvement of

Antamina Comminution Circuit” presented originally at SAG 2011 in

Vancouver, Canada.

SOMOS ANTAMINA

¡NOSOTROS CUMPLIMOS!

Av. El Derby 055, Torre 1, Oficina 801. Santiago de Surco. Lima - Perú

Telf. (51-1) 217-3000 Fax (51-1) 217-3095

www.antamina.com

9. Acknowledgements: