4
reactive ground versus nitrate based explosive isothermal
testing. While high temperature emulsions have been avail-
able for over 25 years, the choice of initiation systems to use
with these products has been limited.
In the USA, unrestricted sleep time of in-hole detona-
tors with PETN base charges is limited to ground tempera-
tures 65.5°C (150°F) or below. In the USA, with explosive
manufacturer qualification and MSHA variance, a blasting
system consisting of an in-hole PETN based non-electric
detonator, packaged detonator sensitive emulsion, and
inhibited bulk emulsion may be used be up to 80°C (175°F)
for 4 hours. In the USA and Canada, under qualification
and approval, in-hole PETN based electronic detonators
have been used underground in ground temperatures up
to 85°C (185ºF) for 4 hours. Other countries have similar
high temperature and/or reactive ground blasting qualifica-
tions and regulations and should be confirmed before use.
When blasting in hot and/or reactive ground with
temperatures greater than 80°C to 85°C (175°F to 185°F),
the global go to initiation system for priming has been the
RDX detonating cord and high temperature emulsion car-
tridge emulsion previously described.
With the introduction of an electronic HMX detonator
and HMX primer, it is now possible to pair this initiation
system with a qualified high temperature emulsion, for an
in-hole delayed blasting system rated for ground tempera-
tures up to 150°C (302°F) for 48 hours. In-hole bottom
initiation as compared to top priming and surface delaying
is known to improve muckpile fragmentation uniformity
and reduce oversize. For blasting in ground temperatures
from 65.5°C to 85°C (150°C to 185°C), the HMX elec-
tronic initiation can expand the blast window from 4 hours
to 48 hours. This allows operations to significantly increase
blast block size and/or reduce blasting frequency.
Numerous mining operations can benefit from the uti-
lization of a HMX based initiation system. Underground
precious and base metal mines with geothermally hot
ground may not have to shut down development headings
for days at time to allow them to cool down before blasting.
Surface operations characterized by high temperature reac-
tive ground may be more able to blast through unexpected
zones of extremely reactive, high temperature ground with-
out resorting to mechanical breakage. Surface coal opera-
tions with reactive hot overburden and/or burning coal
seams now have an initiation system option that permits
safer and improved blasting of hot blocks.
CONCLUSIONS AND FUTURE WORK
1. An HMX based electronic initiation system has been
developed and introduced to the mining industry that
has the potential to improve blast performance and effi-
ciencies in operations with high temperature ground
and/or extremely reactive ground.
2. When combined with a qualified high temperature
emulsion, the HMX initiation system enables blasting
in ground temperatures up to 150°C (302°F) for 48
hours. This extended loading window enables blasting
of larger blocks and/or decreased blasting frequency.
3. The HMX based electronic initiation system permits
bottom in-hole delaying in ground temperatures above
80°C (175°F). As compared to top priming and surface
delaying, in-hole bottom delaying is known to improve
floor quality, muckpile fragmentation uniformity and
reduce oversize.
4. Field evaluation of the HMX initiation system at the
Lihir Mine is continuing.
5. Work on the next generation of the HMX initiation
system is underway and will bring with it expanded
application range and flexibility.
REFERENCES
DMC Press Release, 06 August 2020, “DynaEnergetics
Introduces Igneo ™ Intrinsically Safe ™ Initiating
System for High- Temperature Mining Applications.
Pieterse, D., Small, G., 2022, “Reactive Ground Blast
Management in a South Africa Open Pit Zinc
Mine,” Proceedings of the Forty-Eighth Conference
on Explosives and Blasting Technique, International
Society of Explosives Engineers, Cleveland, Ohio.
Proulx R.P., Scovira D.S., 2000, “Drilling and Blasting
in Hot and Reactive Ground Conditions at Barrick
Goldstrike’s Miekle Mine,” Proceedings of the
Twenty-Sixth Conference on Explosives and Blasting
Technique, International Society of Explosives
Engineers, Cleveland, Ohio, pp. 319–331.
Scovira, D.S., 2015, “Ammonium Nitrate (AN) Based
Explosives and Reactive Ground Awareness,” CIM
Convention, Montreal, Quebec.
reactive ground versus nitrate based explosive isothermal
testing. While high temperature emulsions have been avail-
able for over 25 years, the choice of initiation systems to use
with these products has been limited.
In the USA, unrestricted sleep time of in-hole detona-
tors with PETN base charges is limited to ground tempera-
tures 65.5°C (150°F) or below. In the USA, with explosive
manufacturer qualification and MSHA variance, a blasting
system consisting of an in-hole PETN based non-electric
detonator, packaged detonator sensitive emulsion, and
inhibited bulk emulsion may be used be up to 80°C (175°F)
for 4 hours. In the USA and Canada, under qualification
and approval, in-hole PETN based electronic detonators
have been used underground in ground temperatures up
to 85°C (185ºF) for 4 hours. Other countries have similar
high temperature and/or reactive ground blasting qualifica-
tions and regulations and should be confirmed before use.
When blasting in hot and/or reactive ground with
temperatures greater than 80°C to 85°C (175°F to 185°F),
the global go to initiation system for priming has been the
RDX detonating cord and high temperature emulsion car-
tridge emulsion previously described.
With the introduction of an electronic HMX detonator
and HMX primer, it is now possible to pair this initiation
system with a qualified high temperature emulsion, for an
in-hole delayed blasting system rated for ground tempera-
tures up to 150°C (302°F) for 48 hours. In-hole bottom
initiation as compared to top priming and surface delaying
is known to improve muckpile fragmentation uniformity
and reduce oversize. For blasting in ground temperatures
from 65.5°C to 85°C (150°C to 185°C), the HMX elec-
tronic initiation can expand the blast window from 4 hours
to 48 hours. This allows operations to significantly increase
blast block size and/or reduce blasting frequency.
Numerous mining operations can benefit from the uti-
lization of a HMX based initiation system. Underground
precious and base metal mines with geothermally hot
ground may not have to shut down development headings
for days at time to allow them to cool down before blasting.
Surface operations characterized by high temperature reac-
tive ground may be more able to blast through unexpected
zones of extremely reactive, high temperature ground with-
out resorting to mechanical breakage. Surface coal opera-
tions with reactive hot overburden and/or burning coal
seams now have an initiation system option that permits
safer and improved blasting of hot blocks.
CONCLUSIONS AND FUTURE WORK
1. An HMX based electronic initiation system has been
developed and introduced to the mining industry that
has the potential to improve blast performance and effi-
ciencies in operations with high temperature ground
and/or extremely reactive ground.
2. When combined with a qualified high temperature
emulsion, the HMX initiation system enables blasting
in ground temperatures up to 150°C (302°F) for 48
hours. This extended loading window enables blasting
of larger blocks and/or decreased blasting frequency.
3. The HMX based electronic initiation system permits
bottom in-hole delaying in ground temperatures above
80°C (175°F). As compared to top priming and surface
delaying, in-hole bottom delaying is known to improve
floor quality, muckpile fragmentation uniformity and
reduce oversize.
4. Field evaluation of the HMX initiation system at the
Lihir Mine is continuing.
5. Work on the next generation of the HMX initiation
system is underway and will bring with it expanded
application range and flexibility.
REFERENCES
DMC Press Release, 06 August 2020, “DynaEnergetics
Introduces Igneo ™ Intrinsically Safe ™ Initiating
System for High- Temperature Mining Applications.
Pieterse, D., Small, G., 2022, “Reactive Ground Blast
Management in a South Africa Open Pit Zinc
Mine,” Proceedings of the Forty-Eighth Conference
on Explosives and Blasting Technique, International
Society of Explosives Engineers, Cleveland, Ohio.
Proulx R.P., Scovira D.S., 2000, “Drilling and Blasting
in Hot and Reactive Ground Conditions at Barrick
Goldstrike’s Miekle Mine,” Proceedings of the
Twenty-Sixth Conference on Explosives and Blasting
Technique, International Society of Explosives
Engineers, Cleveland, Ohio, pp. 319–331.
Scovira, D.S., 2015, “Ammonium Nitrate (AN) Based
Explosives and Reactive Ground Awareness,” CIM
Convention, Montreal, Quebec.