12. Stope Blasting

Question 1

What are 4 differences of production mining compared to development mining?

Answer 1

1. larger hole size
2. sometimes backfill
3. larger scale
4. blasting tech/engineer dictates the design

Question 2

What are 7 things that the mining method depends on?

Answer 2

1. depth of deposit
2. rock mass characteristics
3. dip and thickness of deposit
4. hanging wall/foot wall quality
5. production capacity
6. available equipment
7. deposit accessibility

Question 3

What are 4 reasons to use high tech?

Answer 3

1. increase productivity
2. decrease capital demand
3. practical to integrate into operations
4. usable by the local workforce

Question 4

Spacing

Answer 4

distance between holes

Question 5

Burden

Answer 5

distance between rings

Question 6

TRUE or FALSE: Stopes need even spread of explosives

Answer 6

TRUE

Question 7

What are 5 factors affecting blast efficiency?

Answer 7

1. energy distribution
2. energy confinement
3. relief
4. energy level
5. explosive ratio

Question 8

Why is energy distribution important?

Answer 8

uniform energy = uniform fragmentation

Question 9

What are 3 advantages of parallel holes?

Answer 9

1. easy drill set-up
2. greater effective drill footage
3. tonnage of broken rock increases with drill depth

Question 10

What are 2 disadvantages of parallel holes?

Answer 10

1. may require drift slashing

2. slashed drifts are not as stable

Question 11

What are the 3 types of delays?

Answer 11

1. inter-hole
2. inter-row
3. in-hole

Question 12

Inter-Hole Delay

Answer 12

the delay between blast holes (controls geometry/orientation of blast)

Question 13

Inter-Row Delay

Answer 13

the delay between rows (should allow adequate relief)

Question 14

In-Hole Delay

Answer 14

midigates misfires