Open Pit Mine Planning Fundamentals EP

E.P

Geometrical Considerations

Parts of a bench

Cumulative frequency distribution of measured bench face angles (Call, 1986).

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Geometrical Considerations

Functioning of catch benches. Section through a working bench.

3

Geometrical Considerations

Double benches at final pit limits.

Catch bench geometry (Call, 1986).

Typical catch bench design dimensions (Call, 1986). Bench height Impact zone Berm height Berm width Minimum bench width (m) (m) (m) (m) (m) 15 3.5 1.5 4 7.5 30 4.5 2 5.5 10 45 5 3 8 13

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Geometrical Considerations

Safety berms at bench edge

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Geometrical Considerations

Height of reach as a function of bucket size.

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Geometrical Considerations Ramp access for the example orebody.

Example orebody geometry.

Blast design for the ramp excavation.

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Shovel Working Range

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Geometrical Considerations

Minimum width drop cut geometry with shovel alternating from side to side.

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Geometrical Considerations

Minimum width drop cut geometry with shovel alternating from side to side.

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Geometrical Considerations

Diagrammatic representation of the expanding mining front. Isometric view of the ramp in waste approaching the orebody.

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Geometrical Considerations

Dropcut / ramp placement in ore.

Expansion of the mining front.

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Geometrical Considerations

Plan view of an actual pit bottom Showing drop cut and mining Expansion (McWilliams, 1959).

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Geometrical Considerations

Extension of the current Ramp close to the pit wall (McWilliams, 1959).

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Geometrical Considerations

Creating initial access / benches.

Sidehill cut with a shovel.

Shovel cut sequence when initiating benching in a hilly terrain (Nichols, 1956). 15

Geometrical Considerations

Detailed steps in the development of a new production level.

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Geometrical Considerations

Parallel cut with drive by.

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Geometrical Considerations

Parallel cut with the double spotting of trucks.

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Geometrical Considerations

Parallel cut with the single spotting of trucks.

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Geometrical Considerations

Time sequence showing shovel loading with single spotting. 20

Geometrical Considerations

Time sequence showing shovel loading with double spotting.

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Geometrical Considerations

(Continued). 23

Geometrical Considerations

(Continued). 24

Geometrical Considerations

Section and plan views through a working bench.

Simplified presentation of a safety berm.

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Geometrical Considerations

Initial geometry for the push back example.

Cut mining from bench 1.

Cut mining from bench 2. 26

Geometrical Considerations

Safety bench geometry showing bench face angle.

Overall slope angle. 27

Geometrical Considerations

Overall slope angle with ramp included. Interramp slope angles.

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Geometrical Considerations

Overall slope angle with Working bench included.

Interramp angles associated with the working bench. 29

Geometrical Considerations

Overall slope angle with one working bench an a ramp section.

Interramp slope angles for a slope containing a working bench and a ramp. 30

Geometrical Considerations Overall slope angle for a slope containing two working benches.

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Geometrical Considerations

Slopes for each working group. 32

Geometrical Considerations

Final overall pit slope.

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