1
24-051
HMX Based Electronic Initiation System for Blasting in
High Temperature Ground and/or Extremely Reactive Ground
Karl Dufresne
Market Development Manager, DynaEnergetics
Europe GmbH Troisdorf, Germany
D. Scott Scovira
Global Manager Blasting Science, BME USA Inc.
Chatham, MA
ABSTRACT
Blasting in geothermally high temperature ground and/or
extremely reactive ground is an increasing common chal-
lenge for surface and underground mines. Many current
PETN based non-electric and electronic detonators have
manufacturer published in-hole temperature limits ranging
from 55°C to 65°C (131°F to 150°F). When confronting
blasthole temperatures above the manufacturer published
limits, operations may request site-specific guidance and
qualification for use. The advised safe loading window for
in-hole PETN based detonators is often too short to be
practicable for production blasting.
To overcome limitations of PETN based initiation sys-
tems, surface mines with high temperature ground and/or
reactive ground are known to load blastholes with a quali-
fied high temperature bulk emulsion that are top primed
with a cartridge of temperature qualified detonator sensi-
tive emulsion plus an RDX detonating cord downline. As
there is no in-hole delay detonator in this system, blast-
hole timing is accomplished with surface delays. Although
this system is safe, top priming and surface delaying does
influence floor quality and top size fragmentation, and safe
loading windows times reduce blast block size and increase
blasting frequency.
A mining company with a site characterized by geother-
mally high temperature ground plus highly reactive ground
employed a blasting system like the one described above.
The site desires to improve blasting performance by moving
to an in-hole delay initiation system that can withstand the
site ground conditions. At the request of the mining house,
DynaEnergetics developed an electronic initiation system
for application in geothermally high temperature ground
and/or extremely reactive ground conditions.
The DynaEnergetics IGNEO high temperature elec-
tronic initiation system is rated for in-hole use in ground
up to 150°C (302°F) for 48 hours. The detonator consists
of a high strength detonator with an HMX base charge and
thermally resistant downline. To make up a primer, the
detonator is inserted into a booster charge assembly that
is fitted with a small HMX shape charge. This high energy
primer is designed to be compatible and reliable for firing
bulk emulsions, including those with high percentages of
urea inhibition to combat reactive ground. Up to 1000
detonators may be programmed in 1 ms increments up to
1500 ms. The system is controlled by a digital firing panel
that can be used with either a wired or wireless trigger.
The system enables high temperature and/or reactive
ground sites to utilize in-hole delay initiation and realize
the associated performance benefits.
TRADITIONAL BLASTING METHODS
IN HIGH TEMPERATURE AND/OR
EXTREMELY REACTIVE GROUND
Reactive ground is a term used in the mining industry to
describe the condition where an exothermic chemical reac-
tion can occur between sulphide bearing rock and blast
holes loaded with nitrate-based explosives. Reactive ground
conditions increase the risk of explosives deflagration and/
or unplanned detonations.
24-051
HMX Based Electronic Initiation System for Blasting in
High Temperature Ground and/or Extremely Reactive Ground
Karl Dufresne
Market Development Manager, DynaEnergetics
Europe GmbH Troisdorf, Germany
D. Scott Scovira
Global Manager Blasting Science, BME USA Inc.
Chatham, MA
ABSTRACT
Blasting in geothermally high temperature ground and/or
extremely reactive ground is an increasing common chal-
lenge for surface and underground mines. Many current
PETN based non-electric and electronic detonators have
manufacturer published in-hole temperature limits ranging
from 55°C to 65°C (131°F to 150°F). When confronting
blasthole temperatures above the manufacturer published
limits, operations may request site-specific guidance and
qualification for use. The advised safe loading window for
in-hole PETN based detonators is often too short to be
practicable for production blasting.
To overcome limitations of PETN based initiation sys-
tems, surface mines with high temperature ground and/or
reactive ground are known to load blastholes with a quali-
fied high temperature bulk emulsion that are top primed
with a cartridge of temperature qualified detonator sensi-
tive emulsion plus an RDX detonating cord downline. As
there is no in-hole delay detonator in this system, blast-
hole timing is accomplished with surface delays. Although
this system is safe, top priming and surface delaying does
influence floor quality and top size fragmentation, and safe
loading windows times reduce blast block size and increase
blasting frequency.
A mining company with a site characterized by geother-
mally high temperature ground plus highly reactive ground
employed a blasting system like the one described above.
The site desires to improve blasting performance by moving
to an in-hole delay initiation system that can withstand the
site ground conditions. At the request of the mining house,
DynaEnergetics developed an electronic initiation system
for application in geothermally high temperature ground
and/or extremely reactive ground conditions.
The DynaEnergetics IGNEO high temperature elec-
tronic initiation system is rated for in-hole use in ground
up to 150°C (302°F) for 48 hours. The detonator consists
of a high strength detonator with an HMX base charge and
thermally resistant downline. To make up a primer, the
detonator is inserted into a booster charge assembly that
is fitted with a small HMX shape charge. This high energy
primer is designed to be compatible and reliable for firing
bulk emulsions, including those with high percentages of
urea inhibition to combat reactive ground. Up to 1000
detonators may be programmed in 1 ms increments up to
1500 ms. The system is controlled by a digital firing panel
that can be used with either a wired or wireless trigger.
The system enables high temperature and/or reactive
ground sites to utilize in-hole delay initiation and realize
the associated performance benefits.
TRADITIONAL BLASTING METHODS
IN HIGH TEMPERATURE AND/OR
EXTREMELY REACTIVE GROUND
Reactive ground is a term used in the mining industry to
describe the condition where an exothermic chemical reac-
tion can occur between sulphide bearing rock and blast
holes loaded with nitrate-based explosives. Reactive ground
conditions increase the risk of explosives deflagration and/
or unplanned detonations.