Define and Describe

Question 1

Post Pillar

Answer 1

Applies to inclined orebodies from 20-25. These mines have large vertical heights where the mined-out space is backfiled. The fill keeps the rock mass stable and serves as a work platform for the next level

Question 2

Rib Pillar

Answer 2

It is aligned transvers to the stope width and perpendicular to the strike. It separates one stope from another

Question 3

Sill Pillar

Answer 3

Are horizontal pillars that separate levels or stopes

Question 4

Crown Pillar

Answer 4

An ore pillar at the top of an open stope left for wall support and protection from wall sloughing above

Question 5

Production Slot

Answer 5

A cavity that is opened prior to blasting the stope. The primary objective of the production slot is to create a void for the rest of the stope to blast and expand into. Once the slot has been created production can occur

Question 6

Cut-off grade

Answer 6

Any material should be treated as ore if it will provide a contribution to profit (it’s the level of mineral in an ore body which it is not economically feasible to mine. COG is always changing depending on events and the technology available. There may be more than one cutoff grade used

Question 7

Dilution

Answer 7

Is defined as the rest of the material extracted from the ore which is neither ore or development rock. When mined with ore and processed the overall processed material grade is reduced. Can be planes or unplanned:
 Planned: consists of waste rock and low grade material which must be rewarded to extract the ore because of the deposit geometry
 Unplanned: consists of slough material, falling into and mixing with the rock from within the planned stop boundaries

Question 8

sustaining development

Answer 8

Is the development that meets the needs of present day conditions without compromising the ability of future operations and development in mining. Progress is measured in social and economic terms and is accomplished without irreversible environmental degredation or social disruption. The challenge of community level sustainable development is to find drives of development so there are viable social and ecological systems as well as a thriving economy after extraction operates have shut down

Question 9

Draw Ellipsoid

Answer 9

d

Question 10

3 Stages of caving

Answer 10

 Develop area big enough to cave
 Cave initiation, depend on the following:
- Joint density, magnitude and orientation, compressional failure of the rock decreases as the rock strength increases
 cave propagation: vertical or lateral extension of the cave

Question 11

Interactive and independent draw

Answer 11

d

Question 12

Selective vs bulk mining

Answer 12

Bulk: High production, low grade, low cost, external dilution (Block caving-used for massive steeply dipping orebodies)
Selective: low production, high grade, high cost, internal dilution (cut and fill, drift and fill, shrinkage stoping, room and pillar mining, VRM)

Question 13

Ring and drill pattern

Answer 13

d