SURFACE DRILLING
New waste dump sonic drilling record at Bingham Canyon
Waste rock dumps are often placed adjacent to mine pit areas, and as mining expands more room
is needed for the waste rock. Certain physical and chemical characteristics of the waste rock
dumps are often needed to better understand the geotechnical and geochemical behaviour of the
large dumps and to evaluate potential mineral value. Sonic drilling enables the collection of highly
representative samples and excellent sample recovery. This method of drilling has been used for
the re-exploration of dumps, tailings and heap leach pads. Waste rock dumps consist of mainly
unconsolidated material – and it’s often difficult to know how deep they are or what types of
material they contain – which can lead to challenges in drilling. Sonic technology provides a
solution by being able to produce 100% accurate in-situ core samples through varied ground
conditions.
Boart Longyear Drilling Services took on the challenge of drilling core samples from the
unconsolidated waste rock dump at Kennecott Utah Copper’s Bingham Canyon copper mine. The
intent of the drilling was to define the contents of the waste rock dump. The waste rock dump
consisted of rock blast material ranging in size from 254 to 304.8 mm in diameter and was made
up mainly of porphyry deposits. With a targeted depth of 213.36 m, the main goal was to provide a
detailed continuous sample of the waste rock dump material and confirm bedrock depth. Boart
Longyear also needed to install piezometers (water level monitors) and lysimeters (moisture
content monitors). Geotechnical samples would also need to be taken every 6.096 m to confirm
stability and moisture content for the first 60.96 m.
“Sonic drilling is the perfect method for drilling in unconsolidated material, such as the waste
rock dump at the Bingham Canyon Mine, because of its sample recovery rate, straight cased
borehole and the flexibility to offer geotechnical sampling via the split spoon sampler.” The
application achieved more than a 28% increase beyond goal depth and a new Boart Longyear
sonic drilling depth record was achieved of 274.32 m (900 ft). The project showcased the strength
of sonic drilling in unconsolidated material while achieving less than 1% deviation equating to
reliable 100% in-situ core samples.
“As drilling commenced, Boart Longyear took on the task one step at a time by tackling the
depths in stages. For the first 106.68 m, they drilled a 228.6 mm borehole while tripping the drill
string every 6.096 m to pull a split spoon geotechnical sample for the first 60.96 m. For the second
stage, the team drilled to 152.4 m using a 203.2 mm bit with casing. Moving deeper to 228.6 m,
they used a 177.8 mm bit with casing for the third stage. Surpassing their targeted drill depth of
213.36 m, the drillers still had not reached the bedrock formation. Needing to find the true depth
of the waste rock dump, Boart Longyear felt like the rig still had the capability and pullback to go
deeper. Easing forward they drilled to 264.261 m using a 152.4 mm bit with casing. The last stage
couldn’t be drilled with casing as they needed to move to a 101.6 mm borehole. Leaving only the
bit for the final push to 274.32 m – and setting a new Boart Longyear record for sonic drilling –
they reached a 28% greater depth than initially targeted. It took 16 shifts of 12 hours (192 hours)
to accomplish the new record depth for sonic drilling. Boart Longyear lost two of those shifts (24
hours) to rain. Another key accomplishment was the entire depth was reached through dry drilling
and achieved 100% in-situ core samples at less than 1% hole deviation.”
42 International Mining | APRIL 2019
be a popular market for the new drill and one
unit is already there and reportedly is performing
well.
Several other smart features are available for
the drill to facilitate improved cycle times,
including enhanced auto drill and electronic load
sense control. The 77XR is compatible with
Komatsu’s new high-precision GPS tele-remote
operation console and automation solution,
which includes features such as geo-fencing,
auto navigation, obstacle detection and
mitigation, Hawkeye 360 camera system, and
more. Single-pass angle drilling with automatic
mast positioning and adaptive auto leveling
allows operators to perform multiple functions
with a single drill rig.
Economic drill control for smaller
operations
FLANDERS incorporated proven technology from
the FREEDOM for Drills ARDVARC ® drill
automation technology platform to
create DRILLWISE as an economical, modular
product suite for blast hole drills. It is
particularly well suited to crushed stone and
construction operations where the cost of drill
automation is prohibitive, but the need for
drilling accuracy and machine productivity
measurement is beneficial.
To allow the user maximum versatility and
economy, DRILLWISE is comprised of an
economical product suite that can be easily
paired with any drill - no interface with the
control system is required. Data is stored on a
web-based SQL database for ease of access.
DRILLWISE GPS improves drill accuracy, allows
for web-based pattern uploads to the drill, drill
hole data collection, and reporting on drill
productivity. DRILLWISE MONITOR monitors live
drilling and machine data for predictive trending.
MONITOR also provides a foot-by-foot geologic
profile to assist blast hole loading. DRILLWISE
GUARD protects operators from harm and
prevent leaving a running drill unattended, and
GUARD halts drill string rotation if the cab door is
opened. DRILLWISE AUTOLEVEL provides
optimised and automated control of the jack
leveling system on platform drills to ensure the
drill is level and stable during drilling. Finally,
DRILLWISE HAZTECH is compatible with any drill
– and is standard with full drill automations – it
monitors hazards in the drill’s vicinity to help
keep personnel and machinery safe.
FLANDERS told IM: “Since the introduction of
DRILLWISE in fall 2018, DRILLWISE has been
used in both quarry and construction
applications in the eastern US with rollouts
coming soon in Western Australia. Customers
report satisfaction with ease of use and
FLANDERS’ excellent field services in response to
problems, questions, and product improvement.”