2
Care must be taken when mining through these tall benches
and thin beds angled at 35° NE and dipping at 80° into
the quarry floor until it reaches a more manageable bench
height. Although the bench has no cap (weathered) rock,
the thin beds have massive blocks and tend to topple after
each blast depending on the blast egress (quarry advance-
ment). The muck pile will contain excessive boulders if this
is not considered in the blast design.
A review of the geology in the field revealed the need to
classify rock types based on rock properties (strength/den-
sity), chemistry (silica), and structure (bedding/fracturing)
for drill and blast design criteria. Blasting this rock type will
require a unique drill and blast design based on the rock
characteristics to maximize fragmentation and reduce drill,
blast, mining, and crushing costs. The optimization study
under evaluation includes diggability and fragmentation
for plant efficiency.
EQUIPMENT
With the current mining requirements and the produc-
tion rate, most drilling is done with a one-top hammer
drill and operated on a day shift. Blasted muck is loaded
with a wheel loader into two haul trucks. The approximate
haul distance from the blast zone to the primary crusher is
1750 feet (533 meters) with an average round trip being
3,500 feet (1,066 meters).
The primary crushing system opening consists of a
Lippmann 36-inch x 50-inch jaw crusher. The crushed rock
(6-inch &minus) is fed onto a 48-inch belt conveyor and
carried 200 feet (60 meters) to a transfer point with an ele-
vated conveyor. The transfer point has a screen system that
makes a base product if/as needed and conveys it out to a
surge pile. The primary system’s maximum capacity is
500 tons (450 metric) per hour. The equipment listed
below is either brought in as a rental or under contract to
use in the quarry.
DRILL &BLAST OPTIMIZATION
Blasting is contracted to Austin Powder Company. The
blaster in charge reports to the quarry management on
a regular basis. Blasting occurs approximately twice per
Table 1. List of equipment used in the quarry
No. Equipment Model Capacity
1 CAT Loader 988K 9 yd3 (7 m3)
1 Volvo Excavator 380 2.5 yd3 (2 m3)
2 CAT Haul Truck 770G 35 Ton (32 metric tons)
1 Epiroc Drill Tier T40 4–5.5-inch bit diameter
1 Komatsu Hammer PC 360 Exc. Rock Breaker
month. Shots average 35,000 tons (32000 metric tons). The
blaster meets with the driller, engineer, and site supervisor
to discuss the conditions of the shots. The blaster oversees
every aspect of the blast, such as laying out the drill pat-
tern, designing the delay sequence, choosing the explosives,
checking the weather conditions, detonation, and seismic
monitoring. The site supervisor will guard the area and the
quarry engineer will propose the new design by auditing
the shots and sharing the mine plan reconciliation.
A typical blast consists of a three-row staggered pat-
tern occasionally we may elect to use four rows for the pro-
duction bench. Shots are delayed between holes down the
row and progressed between rows. This allows good mixing
action down the row and allows the first row to move out,
so the second row sees only its own burden. Satellite holes
are drilled as needed to break caprock (weathered) or any
heavy burden present on the bench.
As the primary objective for the organizational leader-
ship is “To develop, implement, and continuously improve
a measurable drilling and blasting system that will optimize
the total mining and crushing costs while ensuring compli-
ance to safety and maintaining or reducing the environ-
mental impacts.”
Prior to this optimization study, the drill and blast Base
Case in Sidney quarry was a 9 feet x 11 feet (2.75 meters x
3.3 meters) burden to spacing or a 10 feet x 10 feet (3 meters
x 3 meters) burden to spacing square patterns drilled with a
4-inch diameter hole on a 65–75-foot (20–23 meter) bench
with 3 feet (1 meter) of sub-drill and 15 ft (4.5 meter) of
stemming. Non-electric detonation and gassed emulsion
blasting agents were used at a powder factor of 1.34 lbs./
yd3 (0.8 kg/m3). Drilling and blasting operations were
contracted. The drilling used top hammer drill rigs with
4-inch drill bits with carbide inserts.
The current bench is approx. 70-foot (21 meters) tall,
drilled with changes from 4-inch diameter boreholes on
10 feet x 10 feet (3 meters x 3 meters) to a 5 and ½ inch
diameter 10feet x 12 feet (3 meters x 3.6 meters) burden to
spacing respectively. Gassed emulsion blend is the primary
explosive resulting in a loose muck pile with good loader
cycle times. Most blasts egressed towards the north, as it is
almost perpendicular to the quarry geology, and tends to
have drill deviation of 4 feet.
Each shot was monitored to determine loader and
crusher productivity and compared to the base case sce-
nario to ensure that fragmentation remained optimal
and did not affect productivity, used sensitized emulsion
blended with ANFO providing an excellent performance
to meet the requirements. An evaluation and comparison of
the energy values of different percentages of gassing agents
Care must be taken when mining through these tall benches
and thin beds angled at 35° NE and dipping at 80° into
the quarry floor until it reaches a more manageable bench
height. Although the bench has no cap (weathered) rock,
the thin beds have massive blocks and tend to topple after
each blast depending on the blast egress (quarry advance-
ment). The muck pile will contain excessive boulders if this
is not considered in the blast design.
A review of the geology in the field revealed the need to
classify rock types based on rock properties (strength/den-
sity), chemistry (silica), and structure (bedding/fracturing)
for drill and blast design criteria. Blasting this rock type will
require a unique drill and blast design based on the rock
characteristics to maximize fragmentation and reduce drill,
blast, mining, and crushing costs. The optimization study
under evaluation includes diggability and fragmentation
for plant efficiency.
EQUIPMENT
With the current mining requirements and the produc-
tion rate, most drilling is done with a one-top hammer
drill and operated on a day shift. Blasted muck is loaded
with a wheel loader into two haul trucks. The approximate
haul distance from the blast zone to the primary crusher is
1750 feet (533 meters) with an average round trip being
3,500 feet (1,066 meters).
The primary crushing system opening consists of a
Lippmann 36-inch x 50-inch jaw crusher. The crushed rock
(6-inch &minus) is fed onto a 48-inch belt conveyor and
carried 200 feet (60 meters) to a transfer point with an ele-
vated conveyor. The transfer point has a screen system that
makes a base product if/as needed and conveys it out to a
surge pile. The primary system’s maximum capacity is
500 tons (450 metric) per hour. The equipment listed
below is either brought in as a rental or under contract to
use in the quarry.
DRILL &BLAST OPTIMIZATION
Blasting is contracted to Austin Powder Company. The
blaster in charge reports to the quarry management on
a regular basis. Blasting occurs approximately twice per
Table 1. List of equipment used in the quarry
No. Equipment Model Capacity
1 CAT Loader 988K 9 yd3 (7 m3)
1 Volvo Excavator 380 2.5 yd3 (2 m3)
2 CAT Haul Truck 770G 35 Ton (32 metric tons)
1 Epiroc Drill Tier T40 4–5.5-inch bit diameter
1 Komatsu Hammer PC 360 Exc. Rock Breaker
month. Shots average 35,000 tons (32000 metric tons). The
blaster meets with the driller, engineer, and site supervisor
to discuss the conditions of the shots. The blaster oversees
every aspect of the blast, such as laying out the drill pat-
tern, designing the delay sequence, choosing the explosives,
checking the weather conditions, detonation, and seismic
monitoring. The site supervisor will guard the area and the
quarry engineer will propose the new design by auditing
the shots and sharing the mine plan reconciliation.
A typical blast consists of a three-row staggered pat-
tern occasionally we may elect to use four rows for the pro-
duction bench. Shots are delayed between holes down the
row and progressed between rows. This allows good mixing
action down the row and allows the first row to move out,
so the second row sees only its own burden. Satellite holes
are drilled as needed to break caprock (weathered) or any
heavy burden present on the bench.
As the primary objective for the organizational leader-
ship is “To develop, implement, and continuously improve
a measurable drilling and blasting system that will optimize
the total mining and crushing costs while ensuring compli-
ance to safety and maintaining or reducing the environ-
mental impacts.”
Prior to this optimization study, the drill and blast Base
Case in Sidney quarry was a 9 feet x 11 feet (2.75 meters x
3.3 meters) burden to spacing or a 10 feet x 10 feet (3 meters
x 3 meters) burden to spacing square patterns drilled with a
4-inch diameter hole on a 65–75-foot (20–23 meter) bench
with 3 feet (1 meter) of sub-drill and 15 ft (4.5 meter) of
stemming. Non-electric detonation and gassed emulsion
blasting agents were used at a powder factor of 1.34 lbs./
yd3 (0.8 kg/m3). Drilling and blasting operations were
contracted. The drilling used top hammer drill rigs with
4-inch drill bits with carbide inserts.
The current bench is approx. 70-foot (21 meters) tall,
drilled with changes from 4-inch diameter boreholes on
10 feet x 10 feet (3 meters x 3 meters) to a 5 and ½ inch
diameter 10feet x 12 feet (3 meters x 3.6 meters) burden to
spacing respectively. Gassed emulsion blend is the primary
explosive resulting in a loose muck pile with good loader
cycle times. Most blasts egressed towards the north, as it is
almost perpendicular to the quarry geology, and tends to
have drill deviation of 4 feet.
Each shot was monitored to determine loader and
crusher productivity and compared to the base case sce-
nario to ensure that fragmentation remained optimal
and did not affect productivity, used sensitized emulsion
blended with ANFO providing an excellent performance
to meet the requirements. An evaluation and comparison of
the energy values of different percentages of gassing agents