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Introduction to Tailings ManagementMarch 15, 2011

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Components of a Mine

Tailings

ImpoundmentMill or

Processing Plant

Access Roads

Process Ponds &Water Supply

Open Pits &

UndergroundWorkings

Waste Rock

Dumps

Reclamation

Soil Stockpiles

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What are Tailings?

Waste product from ore

grinding & mineral extraction

Rock ground to sand and siltsizes to maximize liberation of

metals in extraction processes

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What are Tailings?

Two ore more stages of crushing typical

Primary crushing to 12 mm

Fine grinding circuits

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Function of Tailings Impoundments

Operations:

Safe storage of tailings solids &

process water Sedimentation & clarification

of water for reclaim to process

plant Store & attenuate floods at

mine site

Mitigate Acid Rock Potential

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Function of Tailings Impoundments

Closure:

Safe storage of tailings solids &

water Polish water for release to

environment

Reclaimed to meet post-closure land uses

Mitigate Acid Rock Potential

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Challenges

Tailings dams are now

largest dams in the world

Focus of intense

environmental scrutiny

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Tailings Management Studies

Main Components

Site characterization

Climate

Hydrology studies

Geotechnical & geology studies

Hydrogeology studies

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Tailings Management Studies

Main Components

Tailings characterization

Geotechnical properties

Geochemical properties

Technologies assessment

Thickened tailings

Paste tailingsFiltered tailings

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Tailings Management Studies

Main Components

Design criteria

Factors of safety

Seismic design parametersDesign flood events

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Tailings Management Studies

Main Components

Engineering Design

Tailings staging plan

Dam structuresWater balance

Surface water management plan

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Tailings Management Studies

Main Components

Risk Assessment

Continuous evaluation of

environmental risks at eachproject development stage

Enables tracking of risk

mitigation throughout design

process

Failure Modes and Effects

Analysis (FMEA) technique

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Tailings Management Studies

Main Components

Environmental Management Plans

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Tailings Management Studies

Main Components

Closure Plans

Meet long-term land uses

(agriculture, industrial, etc.)Stable against landslides and

seismic loading

erosion

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Tailings Management Studies

Main Components

Quantities & cost estimate

Initial Capital costs

Sustaining Capital costsOperating costs

Closure costs

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Process of Design Studies

ConceptualPreliminary Economic

Assessment (PEA)

Pre-Feasibility

Feasibility

Initial project financialassessment (go/no go)

Bankable feasibility costestimates

Permitting support document

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Project Timelines

Exploration

Preliminary Economic Assessment Pre-Feasibility Feasibility

-30 t = 0 yr 2 3 4

Conceptual

Engineering Pre-Feasibility Feasibility

Engineering Studies

Baseline Studies EIA

Environmental Studies

3+ mths 6+ mths 12+ mths

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Preguntas?