(Factors) Surface Mining Methods

Open Pit

Mechanical Extraction

• Ore strength: Any

• Rock strength: Any

• Deposit shape: Any (preferably tabular)

• Deposit dip: Any (preferably low dip)

• Deposit size: Large, thick

• Ore grade: Low

• Ore Uniformity: Uniform (or sort or blend)

• Depth: Shallow to moderate

Quarrying

Mechanical Extraction

• Ore strength: Any (sound structure)

• Rock strength: Any

• Deposit shape: Thick bedded or massive

• Deposit dip: Any, if thick

• Deposit size: Large, thick

• Ore grade: High (assay not critical)

• Ore uniformity: Uniform

• Depth: Shallow to moderate

Open Cast

Mechanical Extraction

• Ore strength: Any

• Rock strength: Any

• Deposit shape: Tabular, bedded

• Deposit dip: Any (preferably low dip)

• Deposit size: Large moderate thickness

• Ore grade: Low

• Ore uniformity: Fairly uniform

• Depth: Shallow

Augering

Mechanical Extraction

• Ore strength: Any

• Rock strength: Any

• Deposit shape: Tabular, bedded

• Deposit dip: Low dip

• Deposit size: Limited extent, thin

• Ore grade: Low

• Ore uniformity: Uniform

• Depth: Shallow

Hydraulicking

Aqueous Extraction

• Ore strength: Unconsolidated, few boulders

• Rock strength: Unconsolidated

• Deposit shape: Tabular

• Deposit dip: Low dip

• Deposit size: Limited extent, thin

• Ore grade: Very low

• Ore uniformity: Fairly uniform

• Depth: Very shallow

Dredging

Aqueous Extraction

• Ore strength: Unconsolidated, few boulders

• Rock strength: Unconsolidated

• Deposit shape: Tabular

• Deposit dip: Low dip

• Deposit size: Moderate extent, thickness

• Ore grade: Very low

• Ore uniformity: Fairly uniform

• Depth: Very shallow

Borehole

Aqueous Extraction

• Ore strength: Consolidated

• Rock strength: Competent, Impervious

• Deposit shape: Any

• Deposit dip: Any (preferably low dip)

• Deposit size: Moderate to large

• Ore grade: Intermediate

• Ore uniformity: Variable

• Depth: Moderate to steep

Leaching

Aqueous Extraction

• Ore strength: Rubblized, or cavable, permeable

• Rock strength: Competent, impervious

• Deposit shape: Massive or thick tabular

• Deposit dip: Steep

• Deposit size: Any (preferably large)

• Ore grade: Very low

• Ore uniformity: Variable

• Depth: Shallow to moderate