Efficiency Blasting Technology
Why do we blast…??????!!!
1. Mine is usually required simply to lossen the rock so that it can be excavated and transported
2. Result muckpile must simply be able to be efficiency and economically excavated, transported and placed
3. The blasting task is to convert the insitu rock mass into a muckpile of an appropriate fragment size distribution and suitable shape and loosness to suit the available excavation equipment
- withouth causing excesive damage
- noise
- vibration
- fly rock.
“To minimise the overal mining cost and maximise the value of the resulting product”.
Major factor in Fluencing Blast Efficiency
1. Paying attention to Detail
(is the key to safe, efficient blasting)
2. Each operation must be completed as precisely as possible
3. Efficient blast design require a Group Effort
4. Each operation controls the performance of the next
Optimum Blast Performance
Communication
1. Safe blasting Pactice require Good Communication between members of the same group and between groups.
2. Optimum blast design depend on Input from each group
Three key to Optimum Explosive Performance
Explosive Energy Distribution
1. Evenly distributed
2. Hole diameter to bench high Relationship
3. Angel drill
4. Appropriate pattern
5. Accurate drill
Evenly distributed Hole diameter to bench high
Angel drill Accurate drill
Appropriate pattern
Explosive Energy Confinement
1. Confined long enough after detonation
2. The Explosive path of least resistance must be controlled
3. Loaded according to geology
4. Stemming length and material type
5. Timming configuration
6. Accurate delay
Loaded according to geology
Explosive Energy Level
1. Sufficient to overcome the structure strength of the rock and permit controlled displacement
2. Base on the degree of fragmentation & displacement required
3. Account for site sensitivity
4. Evaluate high energy explosive for special site condition
5. Maintain explosive quality control with routine testing
Geological effect
1. Blasting result are in influenced “more by rock properties” than explosive properties
2. Rock properties
3. Rock strukture
4. Rock hardness
Rock stucture
Rock structure and hardness
Blast performance
1. Fragmentation
Factor affecting blasting performance in terms of fragmentation include:
a. oversize fragment
b. Fine
c. Easy of excavation
d. Issues detail to the transport of the muck
e. Mine customer requirement
2. Muckpile shape & digability
a. Muckpile shape and The mine Plan
b. Distribution of sweel and diggablility (pragmentation and swell together define diggabbility or the easy with wich a muckpile can be excavated)
c. Characteristics of excavation equipment
3. Grade movement
4. Damage
a. Wall Damage
b. Slope Damage
c. Coal Roof and edge damage
- Fracturing the top of coal
- Breackage and displacement of the coal edge
- Pushing coal in to the spoil together with overburden
- Mixing dilution material with the coal
5. Enviromental impact
a. Ground Vibration
b. Air blast
6. Downstream handling and processing
7. Cost
Timming
Blasting process
Drilling for multi bench
