blasthole reference book
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Blasthole Drillingin Open Pit Mining
Second edition 2011www.atlascopco.com/blastholedrills
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At Atlas Copco, we strive to make your future more productive. By focusing not
only on today, our goal is to offer reliable, lasting results for years to come.
We put an emphasis on safety to give you a secure working environment.
It's not just a business practice; it's an Atlas Copco state of mindSafety F!rst.
A safe approach to your future
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BLASTHOLE DRILLING IN OPEN PIT MINING 1
Foreword
2 Foreword by Brian Fox Vice President Marketing
Atlas Copco Drilling Solutions LLC
Talking technically
3 From gunpowder to Pit Viper
11 Ergonomics and safety
13 Personnel rig protection
17 An introduction to surface mining
23 Putting rotary drilling into perspective
29 Automated surface blasthole drilling
35 Tricone rotary blasthole drilling
39 Optimizing the rotary drill string
41 Increased productivity with DTH drilling
45 Selecting the right DTH drilling tools
51 Taking advantage of single-pass drilling
53 Blasting in open cut metal mines
63 Drilling in Arctic conditions
65 The new mid range Pit Viper 235
69 Development through interaction - Pit Viper 270
73 Large diameter drilling Pit Viper 351
77 Peace of mind
79 The economic case for routine bit grinding
83 Secoroc Jazz
Case studies
85 Aitik eyes top three efficiency Copper/Sweden
91 Pit Vipers beat the chill Copper/USA
95 Arsarcos choice: both diesel and electric Copper/USA
97 Reopening of Copper Mountain Copper/Canada
99 Innovation through interaction Gold/USA
101 Unforgiving ground Gold/USA
105 Penasquito powers up Gold/Mexico
109 Secoroc hammers go for gold Gold/ Turkey
113 Tough fast-track to Sydvaranger Iron/Norway
117 Steep Wall Open Pit Mining at Zhelezny Iron/Russia
121 Coal mining in eastern Australia Coal/Australia
127 Boosting Siberian energy Coal/Russia
129 Hidden treasure Coal/USA
133 Finding a Perfect Balance Coal/USA
135 Moving mountains Coal/USA
139 Coal and Gold Mining in Kazakhstan
Coal and Gold/Kazakhstan
141 Drilling for coal in Vietnam Coal/ Vietnam
Product specifications
144 Drilling methods guide
146 Specifications guide
147 Blasthole drill rigs
171 Drill rig options
188 Hurricane booster
189 XRVS Compressor
190 Tricone rotary blasthole drilling
196 Bit selection
200 Sealed bearing
205 When to change a bit
206 How a rock bit drills
208 Importance of records
210 Air practices
220 Rock formation & drillability
223 Guides for best bit performance
226 DTH hammer specifications228 Secoroc grinding tools
236 DRILLCare
238 Drill simulator training
239 Glossary of terms
244 Where to find us
For latest updates contact your local Atlas Copco CustomerCenter or refer to www.atlascopco.com/blastholedrills
Contents
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2 BLASTHOLE DRILLING IN OPEN PIT MINING
These are exciting times in the surface mining industry. A lot
has changed since the first edition of Blasthole Drilling in
Open Pit Mining came out in 2009.
Technology is advancing quickly in the industry, and we pride
ourselves as being among the leaders. Our Rig Control System
(RCS) has established itself as a very reliable platform from
which to build advancing levels of automation. RCS is avail-
able on all Pit Viper Series models today, and well integrate
it to our smaller machines as we move forward. Teleremote
operation and autonomous drilling are no longer futuristic
thinking. We have demonstrated such advanced technology,
and continue to test and prepare for commercial release.
While we are moving towards unmanned operation of drills,we realize that it doesnt fit every application. Weve put a
great deal of focus on the safety of mine personnel on and
around the rig. Options designed to make it easier to access
and service equipment are being developed by our Engineering
team with heavy input from our customers.
I was reminded recently of a long-standing quote in the mining
industry. Ive never seen a shovel pass a drill yet. Very true,
and as shovels and trucks get larger and faster, we must con-
tinually improve the productivity of our machines. As world
demand increases, the amount of material mined annually con-
tinues to grow. Further, increasing strip ratios and lower ore
grades require substantially more material movement to get
the same output. Productivity improvements alone wont keep
up. The availability and utilization of the rigs must continue
to increase as well.
Atlas Copco prides itself in building highly productive, reliable
equipment. As the equipment is only as good as the support
behind it, weve undertaken a major effort to improve our parts
availability, service capacity (including manpower, competence
and service outlets) and technical documentation. Were never
satisfied with where we stand, and are always looking for inputfrom the mining industry to help guide us.
Committed to Sustainable Productivityis Atlas Copcos brand
promise. This second edition of Blasthole Drilling in Open
Pit Mining contains some great case stories showing how our
brand promise translates to real-world results.
We hope you enjoy this second edition.
Brian Fox
Vice President, Marketing
Drilling Solutions LLC
Foreword
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BLASTHOLE DRILLING IN OPEN PIT MINING 3
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GunpowderThe application of blasting agents
apparently began in Hungarian mines
sometime during the sixteenth cen-
tury. To make better use of the explo-
sive force, miners star ted to place the
powder in holes and it is certain that
drilling and blasting were used in sev-
eral German and Scandinavian mines
early in the seventeenth century, for
instance at the Nasafjll silver mine in
Lappland in 1635, and in 1644 at theRros mine in Norway.
One-man drilling with the help of
a drill steel and sledgehammer was
the established technology used in the
eighteenth century. This physically
demanding technique evolved only
slowly but, despite the mechanization
of other industries, remained in quite
widespread use until well i nto the
twentieth century. However, powered
drills did start to mount a challenge in
the 1800s, the competition in the USA
being symbolized by John Henry who
in 1870 hammered through 14 feet in
35 minutes while the steam drill only
completed nine feet.
The first patented rock drilling ma-
chine was a steam driven percussion
drill invented by J. J. Couch in Phila-delphia in 1849 but it may have been
prec eded by a ma ch ine ma nufac-
tured by the Scottish engineer James
Nasmyth ten years earlier. This patent
spurred a period of rapid development,
accelerated in the 1860s by Nobels
inventions of the blasting cap and
safe dynamite explosives. From 1850
to 1875 some 110 rock drill patents
were granted to American inventors
and seven for drill carriers while 86
patents were issued in Europe duringthis period.
In 1851 James Fowle, who had
worked with Couch, patented a rock
drill that could be powered by steam
or compressed air and could rotate the
drill steel by means of a ratchet wheel
controlled by the piston's back-and-
forth movement. In the 1860s large
scale rock drilling machines were built
for tunnelling by engineers in Europe
and the United States. One of the most
successful of these early rock drills
was the second refined version of the
Burleigh rock drill, which was put into
service in October 1866 at the Hoosac
tunnel in Massachusetts. The perfor-mance at this tunnel project showed
that rock drill development had taken
the step from an experimental product
to a proven and rather reliable technol-
ogy.
In 1871 the American inventor Simon
Ingersoll patented a steam powered rock
drill, later to be operated on compressed
air. Ingersoll formed the Ingersoll Rock
Drill Company in the same year. During
the following year Ingersoll purchased
the Fowle-Burleigh patents and alsomerged with the Burleigh company.
The Pit Viper is designed for production drilling of large holes in hard rock conditions.
From gunpowder to Pit Viper
Drilling and blastingThe rotary blasthole drilling rigwas a long time coming. Gun-powder was invented in Chinaabout 1000 A.D. But in Europe atleast it took another 500 years ormore before miners started to useit for blasting and a further threecenturies for the introduction ofmechanized drilling in surfacemines. Mobile blasthole drillingrigs have been in use for onlysome sixty years.
Drilling with sledgehammer was the establishedmethod before the development of the rock drill.
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4 BLASTHOLE DRILLING IN OPEN PIT MINING
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The new compact rock drill launched by
Ingersoll was a simple and strong design
with few moving parts. The designers
had kept in view the tough conditions
in which the rock drill had to work, and
the contemporary technical opinion
regarded his new rock drill as the best
yet available on the market. During the
years to come Ingersoll bought out many
small firms and expanded his company.
The Ingersoll Rand name came into
use in 1905 through the combination of
Ingersoll-Sergeant Drill Company and
Rand Drill Company.
The AB Atlas enterprise had been
founded in February 1873 at a time
when the Swedish railway net was
being rapidly expanded. Three years
later, now with 700 employees and the
Stockholm shops completed, AB Atlas
had delivered more than 600 railway
wagons. Diminishing demand from therailroad sector, combined with years of
losses, led to a reconstruction in 1890.
During the years to follow new product
lines were added, including compressed
air tools, compressors, diesel engines
and the first Atlas rock drill which was
launched in 1905.
Further development
The design of the first Atlas rock drill
featured an advanced rifle bar rota-tion but with a weight of 280 kg (617 lb)
it was very heavy for manual use.
Immediately and for the next 25 years
Atlas focused on light weight hand
rotated drills like the Cyclop, Rex,
and Bob. The real Atlas winner among
lightweight hand-held rock drills was
the RH-65 from the year 1932. This
machine had more efficient shank and
chuck designs for better steel guidanceand longer shank life. Used with the
new pusher leg feed system developed
in the 1930s, the RH 65 was the most
important element in what was later
to become known as the "Swedish
method" of underground drilling.
In the United States Ingersoll-Rand
expanded into pneumatic tools in 1907
by acquiring the Imperial Pneumatic
Tool Company of Athens, Pennsylvania.
In 1909 the company bought the A.S.
Cameron Steam Pump Works and en-
tered the industr ial pump business.
Ingersoll Rand also acquired the J.
George Leyner Engineering Works
Com-pany. This firm had developed a
small, pneumatic hammer that could be
operated by one man. This Jackhamer
introduced in 1912 became a popularitem, and the company progressively
developed the design as well as sup-
plying compressors to the expanding
construction and mining industries in
North and South America
Rock drilling tools
The parallel improvement of drill steel
quality had started dur ing the 1890s
The Ingersoll rockdrill was a simple and strong design with few moving parts.
In 1871, a number of patents were issued to the
inventor Simon Ingersoll, who started the Inger-
soll Rock Drill Company The machine produced
by Ingersoll was at this time regarded as the best
rock drill yet produced, and it was followed inthe mid 1880s by another success, the famous
Ingersoll Eclipse machine.
The first drill made by Atlas "pneumatic rock drill No. 16" had a weight of 280 kg (617 lb) and was heavyand difficult to handle - at least two men were needed to move it.
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BLASTHOLE DRILLING IN OPEN PIT MINING 5
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with development of heat treated drill
steel that could better resist deformation.
But sharpening the tips required exten-
sive haulage of tons of drill steel between
drilling sites and the work shops. The
detachable drill bit was developed in
1918 by A L Hawkesworth, a foreman
at the Anaconda copper mine in Butte,
Montana. The first versions used a dove-
tail joint to the drill steel while later ver-
sions were threaded or tapered. The rods
were retained at the workings and used
with new or re-forged bits.
In Europe during the German col-
lapse in 1918 a team was formed at
the Osram lamp factory to develop
cemented tungsten carbide as a substi-
tute for industrial diamonds. In 1926 the
first cemented tungsten carbide became
available as a magical machine toolfor turning and milling operations. Early
tests were made in 1928 trying to use
tungsten carbide bits for rock drilling in
German mines and before World War
II promising results were obtained. By
this time the research team had scattered
and some members had been forced to
leave the country. One of these, Hans
Herman Wolff, found refuge in Sweden
where he worked at the Luma lamp fac-
tory. Dr Wolff manufactured a number
of bits according to designs provided byErik Ryd at Atlas.
The bits were tested in the Atlas
test mine. In 1942 Atlas, Sandvik and
Fagersta signed a cooperative agree-
ment and it was not until 1945, after a
long improvement process, that the new
cemented tungsten carbide drill bits
were as economical to use as conven-
tional steel bits.
The post-war years saw Atlas achieve
further major advances. In 1948 the com-
pany introduced an RH 65 upgrade, the
RH 656, which was designed to use thenew cemented carbide tipped drillsteels.
The superior performance of the Light
Swedish Method was exploited world-
wide and culminated in 1962 with the
completion of the Mont Blanc tunnel.
With development of highly mecha-
nized drill rigs and with the introduc-
tion in 1973 of the COP 1038 hydraulic
top hammer drill Atlas Copco laid the
foundation to become a world leader in
top hammer drilling technology. (See
article from wagon drill to SmartRig,Surface drilling, Fourth Edition 2008).
Rotary bits
Rotary drilling with drag bits was the
common method used in oil drilling.
These bits were suitable when drill-
ing in soft formations like sand or
clay but not in rock. The solution for
drilling large diameter holes in rock
was by using rotary crushing technol-
ogy instead of trying to cut hard rock
with drag bits. The roller cone bit wasdeveloped by Hughes and Sharp, and
the US patent for a dual roller cone
bit was issued to Howard Hughes Sr.
in 1909. This new type of bit had two
interlocking wheels with steel teeth,
and penetrated the rock by crushing
and chipping. The success of the new
bit led to the founding of the Shar p-
Hughes Tool Company, and after
Sharp's death in 1912 the name was
changed to Hughes Tool Company.
The company continued develop-
ment of the roller cone bit and in 1933two Hughes engineers invented the
tricone bit. This bit had three conical
rollers equipped with steel teeth.
Drilling was accomplished by trans-
ferring a pulldown force to drive the
teeth into the hole bottom. The three
roller cones turned as the drill st ring
was rotated, and the teeth crushed and
spalled the rock.
While tophammer drills could be
used for small blast holes in rock, this
method was not suitable for large holediameters; for these rotary drills were
the best alternative. However, as drillers
sought to use the rotary system for pro-
gressively harder rock formations so
the feed force (pulldown) available had
to be increased. Roller cones with long
steel teeth were used in softer forma-
tions for gouging the formation while
roller cones with shorter teeth were
used for crushing and spalling harder
formations.
A parallel development of the tri-
cone bits made it possible to use these
high loads on bits. To extend the life of
the bits in hard and abrasive rock the
steel teeth were replaced by cemented
tungsten carbide inserts. Tungsten car-
bide inser ts have sign if icantly in-
creased the number of blast holes thatthe roller cone bits are able to drill.
The US patent for a dual roller cone bit was issued to Howard Hughes Sr. in 1909.
The Secoroc Omega sealed bearing tricone bits
are now regarded as the ultimate blasthole b it
solution.
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6 BLASTHOLE DRILLING IN OPEN PIT MINING
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Improvements in materials have con-
tinued to increase the life of the bear-
ings so the cutting structures can be
fully utilized. While the geometry of
the roller cone bit is much the same as
the original bit patented in 1933, the
material and technology currently uti-
lized is cutting edge.
Downhole drillingtechnology
Meanwhile, manual lightweight pneu-
matic drills had also underpinned the
expansion of bench mining in open cut
mines and quarries. But in the 1930s
downhole drills (DHDs ) were intro-
duced for drilling deeper holes. The
main initial development of this tech-
nology took place in Belgium and the
United States. Atlas designed a down-
hole unit in the mid-thirties that was
used with good results in two Swedish
limestone quarries until the 1950s but
the company then ceased further DHDdevelopment, only re-enter ing the
market in 1969 with the COP 4 and COP
6 down-the-hole hammers. Followed by
the valve less COP 32 42,52 and 62 from
1978, where still COP32 is in use. In
the early 90s COP44,54 and 64 where
introduce. A high pressure hammer
based on a design from Secoroc, a high
performance hammers series unbeaten
in blast hole drilling until replace by
COP Gold series of hammers in the
beginning of 2000nds.
In 1955 Ingersoll-Rand introduced a
new downhole drill design and started
to establish downhole drilling on a truly
commercial basis. The Tandematic,
which at the time was claimed to pro-
vide the highest drilling speed ever
attained by a downhole drill, was sup-
plied in two standard sizes the DHD
275 for 4* inch and 5 inch holes and
the DHD 1060 for 6 and 6 inch . This
later enabled the company to build drill
rigs adapted to be used either for rotary
drilling or with downhole hammers. The
main difference is that downhole drill-
ing requires more air, and consequentlythese drill rigs had to be equipped with
a larger capacity compressor and a more
powerful diesel or electric engine.
Downhole drill technology went
through rapid change in 1960s and 70s.
In fairly rapid succession I-R developed
the DHD 325 ( their first 6"hammer),
DHD 325A, DHD 16, DHD 1060,
DHD 1060 A and B models, DHD 360
(all 6"drills) and corresponding larger
and smaller models, up to the current
line of DHDs. Probably the most sig-
nificant change in DHD technology
was the advent of the valveless DHD.
Drill efficiency and lifedramatically
improved with the elimination of the
flapper valve. During the 90s the QL
series of hammers came with the unique
QL (Quantum Leap) design , a still valid
patent. This features makes it possible to
have the piston stroke pressurized 80%
of its distance compared with 50% for
other hammer design. The QL feature is
also used in the TD hammers series for
deep hole drilling.Of course higher pressure and vo-
lume air from the air compressor advan-
cements produced the performance one
sees today. Re-entry to the downhole
drill market at 6 bar** in 1969 also ena-
bled Atlas Copco to take advantage of
improved air compressors and develop
more and more powerful downhole
hammers, reaching 18 bar in the early
1980s and more recently 25 bar and 30
bar in the larger current hammer sizes.
Big picture; Airpowered DM-3 with a DRD-2 Rotary head from the late 1950's. Inset; Tractor mounted
Drillmaster, air powered with a DRD Rotary Head from the early 1950's.
The Quarrymaster from 1948 was equipped with a huge 8" bore drifter. *1 inch = 25.4 mm, **1 bar = 14.5 psi
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BLASTHOLE DRILLING IN OPEN PIT MINING 7
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Drill rigs
The mobilization of rotary and down-
hole drills was linked to significant
post-war changes in rotary drilling tech-
nology. Up until then rotary drilling
had been used in water well drilling and
surface mining using f luid circulation
to clean cuttings from the hole. Coal
mines were using rotary drilling insoft overburden, removing the cuttings
with augers. In the late 1940s it was rea-
lized that air was an effective flushing
medium with considerable advantages
over water, doing a better cleaning job,
protecting the bits and eliminating the
difficulties of supplying water.
Experience also proved that air flu-
shing improved the penetration rate of
rolling cutter bits such as tricone bits
and extended their life. By using effi-
cient air flushing to keep the bottomof the drill hole free from cuttings the
rock breaking process became more
efficient.
In 1948, Ingersoll-Rand entered the
large-diameter blast hole market by
launching the Quarrymaster. It really
was not a rotary drill, but a large self
propelled mounting in the 40,000 lb*
weight range, designed with on board
air and a long drill tower to drill 6 inch
to 8 inch diameter holes for mining
and quarry applications. The original
Quarrymasters were equipped witha huge 8"bore drifter, know as the
QD8. This was a piston drill with
the drill steel attached directly to the
drif ter piston. The blow frequency
was in the range of 200-300 blows per
minute. The drifter used a large rifle
bar rotation system. Achieving decent
wear life between the rifle bar and
rifle nut was sometimes a problem in
tight ground. This was a single pass
drill system, hole depth was limited
by the tower length. The steel systemwas a heavy wall tubular product, in
the range of 4"OD, and was extremely
heavy. Since there was no steel change,
the weight didnt seem to be much of
an issue.
Quarrymasters were used in some
large iron mines in Canada and the
Atlantic City Iron Ore Mine in Wyoming.
Numerous Quarrymasters were used in
the rock excavation for the St Lawrence
Seaway in Canada.In the same year also Atlas intro-
duced its first mobile rubber tired drill
wagons for top hammer drilling, but
these were not equipped with any tram-
ming machinery and were intended for
considerably smaller hole diameters.
I-R development work with downhole
drills in the early 1950s brought about
changes to the drill mounting business.
First, the Quarrymaster was equipped
with the newly developed QRD rotary
head, and this along with the new DHD325 down hole drill, made for a produc-
tive but heavy and bulky package.
The Drillmaster design, a somewhat
smaller rotary drill, was introduced about
1955. It produced the same performance
as the Quarrymaster in a smaller and
less costly package. Upgraded versions
of the Drillmaster, the DM-1, DM-2
and DM-3 followed in quick succes-
sion. Originally equipped with sliding
vane air compressors up to 900 cfm**,
all were updated to the screw compres-
sor design. The Drillmaster line was
equipped with the DRD and later DRD 2
rotary head to provide drill string rota-
tion. As with the QRD rotary head the
DRD was powered by a vane air motor
and several steps of gear reduction.
All of these drills only used hydraulic
power, from an engine driven hydrau-
lic pump off the cam shaft, to oper-
ate the jacks, tower raising cylinders,
break-out wrench, and dust collector
drive motor. Neither rotary head was
very useful in supplying straight rotary
power for tricone bits, hence the future
development of the T-4 and DM-4
with hydraulic powered rotary head for
straight rotary drilling. I-Rs first truck
drill was called the Trucm package.
The drill frame package was mounted
on a customer provided truck, often a
used Mack truck. However, none of thestandard truck designs proved very
successful. The normal channel truck
frames were not sturdy enough, result-
ing in many cracked and broken truck
frames. I-Rs answer to this problem
was to join hands with Crane Carrier
Corp of Tulsa, OK, and mount the drill
components and tower directly on an
I-beam chassis frame, often used for
mounting construction cranes. This
product became the TRUCM-3 and the
same style mounting carried over to theT-4 and T4W introduced in 1968.
A major new stimulus for blasthole
drilling rig development generally was
the introduction in the 1950s of mil-
lisecond delay blasting. This allowed
blaster s to desig n mult i-hole large
volume blasts that could be used for
mass production techniques in open
The truck mounted T4BH was introduced in 1968.*1 lb = 0.45 kg, **100 cfm = 42.2 l/s
Secoroc COP64 Gold downhole hammer.
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8 BLASTHOLE DRILLING IN OPEN PIT MINING
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cut drill and blast mines. In turn this
required the introduction of large,
mobile drilling rigs able to drill large
diameter holes using tricone bits, aswell as the formulation of cheap bulk
mining explosives based on ammonium
nitrate and nitro-glycerine. These and
other developments helped the mining
industry to keep the costs of bench
drilling substantially unchanged during
the 1950s and 1960s, despite increasing
wage costs.
The Quarrymaster and TRUCM ma-
chines were made progressively more
self-contained through the 1950s. By
the end of the decade the air supply was
up to 10 bar and the marketing slogan
Pressure is Productivity was promot-
ed. The drill r igs and rock drills were
sold together to maximize revenue but
this did encourage other manufacturers
to build competing rock drills.
Hydraulics technologyadds to drillers options
The similarities between the air requi-
rements of rotary and downhole drill-
ing made the design of rigs able todo both an economically attractive
proposition. In 1965-66 Ingersoll-Rand
started work on the switch to hydraulic
powered rotation for rotary and down-
hole drilling, launching first the truck-
mounted T4W for water well drilling
in 1968. In the same year this r ig was
modified to make a truck-mounted
blasthole rig with a 5-rod carousel, the
Drillmaster T4BH, which could drill
holes of up to 7 inch diameter and
was successfully offered for coal minedrilling throughout the 1970s. The
designers also used the power unit,
tower and other components to create
the crawler-mounted Drillmaster DM4
blasthole dr illing rig. This machine
was designed from the ground up
for both rotary and downhole drill-
ing. A 36 ft* high tower incorpo-
rated a hydraulically indexed carousel
housing seven 25 ft rods. The rotary
head featured an axial piston hydrau-
lic motor and single-reduction worm
gear for rotation, providing 5.6 kNm
of torque and rotation speeds from 0
100 rpm. There was a choice of diesel
engine or electric motor for the spring
mounted floating power pack and a
range of diesel or electric compres-
sors, enabling use of either rotary or
downhole drilling with the companys
DHD-15, -16 or -17 downhole drills.The excavator style crawler undercar-
riage had tracks with 22 inch triple bar
grousers driven by hydraulic motor
through a planetary gear drive and
chain reduction.
In the marketplace the DM4 com-
peted with the more powerful electric
top drive blasthole drill ing rigs. The
late 1960s and 1970s saw heavy take-
up of the DM4 rig by the Appalachian
coal mines in the United States. And
the combination of patented rig, drill
and drill rod technology was very
profitable for Ingersoll-Rand. The use
of hydraulic power for rotation and
non-drilling functions meant that more
air could be made available for rotary
and, especially, for downhole drilling.
This engendered an air race in the
late 1960s and 1970s. The independent
downhole dril l manufacturers were
able to build machines that could drill
at 130 ft/hour in the 6 8 inch diameter
hole range faster than a rotary drill
could achieve in this hole size range,par ticularly when drilling in harder
rock types.
The development of screw compres-
sors to supply air for drilling rigs at up
to 20.6 bar led to the 1970s introduction
of an airend to supply both low pres-
sure and high pressure air. These units
were used in portable air compressors
and also onboard drilling rigs, where
they enabled downhole drills to outper-
form rotary drills in the 6 - 8 inch
hole sizes in hard rock mines. However,
rotary drills were still better for rock
compressive strengths up to mediumhard limestone.
The higher pressures were also very
beneficial for water well drilling, in
which air pressure must be sufficient
to evacuate the ground water pressure
from the hole while drilling.
Expansion of theDrillmaster range
Significant corporate developments and
one major product launch impacted the
Ingersoll-Rand drilling business in the
mid-1970s. Firstly, in 1973 the company
acquired DAMCO (Drill And Manu-
facturing Company) in Dallas, Texas,
who built mechanically driven pre-split
drilling machines for quarrying and
light coal str ipping. These expanded
the Drillmaster range down to the
20,000 lbf* bit weight class. The rigs
also used the rotary table drive and kelly
bar concept, which lightened the tower
structure sufficiently to accommodate
rod long enough to drill 40 50ft holesin a single pass if required. Ingersoll-
Rand added their own compressors to
create the DM20, DM25, DM25-SP
(single-pass), DM35 and DM35-SP
rotary rig models. Then, in 1975, the
company bought the Sanderson Cyclone
Drill Company in Ohio, USA, adding
12 models designed for the water well
market.
The next extension of the size class
range came with the launch of the
Drillmaster DM50 with 50,000 lbf ofweight on the bit. In this machine the
The DM50 could use bit loads up to 50,000 lbf
and was launched in 1970.
*1 ft = 0.304 m
**1,000 lbf = 4.44 kN = 453 kilogram-force
Rotary table and Kelly bar concept.
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BLASTHOLE DRILLING IN OPEN PIT MINING 9
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diesel engine drove the hydraulic power
pack from one end of the crankshaft and
the compressor was directly coupled to
the other. This concept was also used on
the next two drills to be launched. The
first one was a new crawler mounted
rig for rotary or downhole drilling, the
DM45 with 45,000lbf weight on bit.
This was followed by a conceptually
similar top drive rotary or DHD model,
the DM30 and a specialized rotary table
variant, the DM-35I, which was intro-
duced in the 1980s for drilling underwa-
ter in phosphate mines. It featured a dual
kelly system that allowed explosives to
be charged through the annulus between
the outer and inner kelly. The inner kelly
would then be removed for blasting.
Later the DM 40SPi was developed for
drilling and shooting deeper holes.
Development of largeblasthole drills
Towards the end of the seventies, the
company started designing drill rigs
more specifically aimed at the base
metal mining market, using power
pack concepts developed for deephole
drilling. So far, neither air-powered nor
hydraulic drive rotary nor downhole
drills had challenged the electric motortop drive rotary rigs manufactured in
the United States for the 12 15 inch
diameter hole market. These machines
by now had very high weights on bit
in the range 100,000 120,000 lbf,
partly due to the weight of the electric
motor for the rotary head, but were
not suitable for live tower operation.
Ingersoll-Rands first response was
in 1979 with the development of the
Drillmaster DM70, able to drill 10 inch
diameter holes in metal mines and up
to 12 inch holes at coal mines using8.6 bar air for rotary drilling. And in
1979 the company launched the DM-H
(Drillmaster Heavy), the fi rst truly
modern large blasthole drilling rig to
be used for low pressure rotary drilling
of 9 7/8- 12 1/8inch holes with bit loads
up to 90,000 lbf.
The DM-H used hydraulics for both
drilling and non-drilling functions
and featured a hydraulic propel exca-
vator type undercarriage with easily
replaceable grouser pads and in-linecomponents on the deck. It was equip-
ped with a rotary screw compressor
and a live tower with patented angle
drilling system. The tower pivot point
was flush to the drill deck and within
the dust curtain, reducing the length
of unsupported drill rod. It was an all-
purpose machine, with a single-pass
version added in the mid-1980's. The
machine has been upgraded over the
years al-though replaced by the Pit
Viper 351 for hard rock applications.
At much the same time the company
started to offer electric powered ver-
sions of the DM 45 and other models
if customers wanted them, for instance
for use in open pits where the other
key equipment was electric powered.
However, although these machines
had electric motor power packs they
retained the hydraulic rotation system.The first electric drill rig was the
DM7B delivered to Clarksburg in 1977,
followed a year later by the DM100
delivered to Rock Springs.
After recovery from the recession
of the early 1980s, Ingersoll-Rand
launched a medium range Drillmaster,
the DM-M designed for rotary drill-
ing of 9 7/8inch holes with bit loads up
to 60,000 lbf. Three of the first four
DM-M's went into operation at Peabody
Energy's new North Antelope &Rochelle Mine in the Wyoming Powder
River Basin, now one of the two larg-
est coal mines in the world. Now, over
25 years later, the prototype DM-M is
still in operation. The machine featured
a carriage feed system with wire rope
cables, resulting in a lighter tower and
lower center of gravity.
In 1989 this model was upgraded
to the DM-M2 on which maximum bit
load was increased to 75,000 lbf and
the hole size capability extended up to
10 5/8inch. Stability was improved aswell. In 1990-91 the company intro-
duced the DML for multi-pass drilling
to 180 ft hole depth.
This new model could drill from
6 to 9 7/8inch (200 250 mm) diam-
eter holes in rotary mode, and 6 87/8inch using a downhole hammer.
Following a development project based
on a customer consultation exercise the
DM-M3 was launched at MINExpo
1992. Designed primarily for deep
drilling of overburden for cast blastingin large coal mines, the first production
Milestones in development
Year Model Load on bit
1948 Quarrymaster drifter
1955 DM3 30,000 lbf
1968 T4BH 30,000 lbf
1969 DM4 40,000 lbf
1970 DM50 50,000 lbf
1979 DM-H 90,000 lbf
1983 DM-M 60,000 lbf
1990 DML 60,000 lbf
1992 DM-M3 90,000 lbf
2000 PV-351 125,000 lbf
2004 PV-270 75,000 lbf
2008 PV-235 65,000 lbf
The DM-H, launched in 1979, could be used with
bit loads up to 90,000 lbf (400 kN).
The first Pit Viper 351 was launched in 2000 and
used at the Morenci copper mine in Arizona.
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10 BLASTHOLE DRILLING IN OPEN PIT MINING
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DM-M3 went into operation in 1993 at
Arch Coal's Black Thunder Mine, one
of the largest coal mines in the world.
For this new model, the designers rai-
sed bit load to 90,000 lbf and the hole
diameter range up to 12 inch while a
new patented cable feed allowed the use
of 40 ft long drill rods.
The launch of the Pit Viper
Although difficult market conditions
restricted investment in the mid-1990s,
during 1997 the company started work
on a new generation blasthole drilling
rig design.
To differentiate this new range from
the Drillmaster series, which initially
was designed for drilling large holes
in coal mining and soft rock, this new
series was - from the very beginning
- specified and designed for produc-
tion drilling of large holes in hard rock
conditions.The first one out was the Pit Viper
351, which was successfully launched at
MINExpo 2000. Weighing 170 tonnes,
measuring 53 feet long, and equipped
with a CAN-bus control system with
seven on-board computers, the new Pit
Viper 351 was at that time the largest
and most advanced drill rig of its kind.
The advanced control system allowed
the drill pattern to be transmitted to
the drill rig via a radio network, and it
also featured production monitoring,
rock recognition and a GPS navigation
system.
A few months after the Minexpo
show, in April 2001, the PV-351 was
put to work at the Morenci copper mine
in Arizona for final testing and evalu-
ation. The mine had a f leet of 16 drill
rigs from a variety of manufacturers, so
in addition to the new rig being used for
drilling in the hard igneous rock condi-
tions, this was an excellent opportunity
for benchmarking the PV-351 with the
other brands.
The application required 12 inch
diameter single pass drilling of 57 ft
deep blastholes using up to 90,000 lbf
weight on bit (of the 125,000 lbf capac-
ity). The test was successful: the
PV-351 drilled some 2.2 million feet by
August 2004 at a recorded average rate
of 60,000 feet per month and in some
months even more than 80,000 feet per
month.
Later the same year the multi-pass PitViper 275 was launched at MINExpo
2004. Based on the experience from the
PV-351, combined with customer con-
sultations, a project had been initiated
for development of the PV-270 series.
These drills were specified for a 75,000
lbf bit load capacity and were featured
a similar cable feed system and auto-
matic cable tensioning to that on the
larger PV-351. The multipass version
PV-275 with a 195ft depth capacity was
delivered for a test in December 2003 atPeabody's Kayenta coal mine in Arizona
where it was used for cast blast drilling
for removal of the overburden. This
first machine is still in use there and,
as a result of the good performance, the
mine decided to invest in several addi-
tional units. One of these is prepared for
quick change between a multi-pass and
a single-pass tower as an option to be
adapted for different applications at the
mine.
The first mine to use the single pass
version, the PV-271, was the Barrick
Goldstrike mine near Elko, Nevada.
Since the PV-271 arrived at the mine in
April 2004 it has been problem-free, and
holds an impressive track record with
an average penetration rate of 199 ft per
hour. The long component life and also
the automatic tensioning adjustments for
the cables are much appreciated by the
mine.
Following this t radition of product
launches in Las Vegas, the latest addi-
tion to the Pit Viper series - the PV-235- was shown at MINExpo 2008. This
is an advanced mid- range drill for bit
loads up to 65,000 lbf, with the RCS Rig
Control System available as an option.
Acknowledgements
Editors: Kyran Casteel and Ulf Linder
Contributions: Guy Coyne, Ron Buell,
Kenneth Moff it t, Brian Fox, John
Stinson, Dustin Penn, Gunnar Nord,
Sverker Hartwig, Jim Langford, DianeNorwood, Darwin Hollar, Ewald Kurt.
Big picture: The electric PV-351E at the Boliden Aitik Mine. Inset: The workplace of today with RCS control
and automated functions.
The Pit Viper 235 shown at MINExpo 2008.
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BLASTHOLE DRILLING IN OPEN PIT MINING 11
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Ergonomics and safety foroperators
Today much has changed with regard
to operators, machines and machine
interfaces. Twenty years ago the indus-
try took a macro view of an operators
ability to complete a shift without tiringor having an accident. Today designers
work to a micro requirement; neither a
hand nor a finger must be injured over
a 30-year career doing the same func-
tion.
In the past the requirements were for
gauges and levers to be properly placed
to avoid human strain during the work
shift. Now engineers analyze site paths,
a process of ensuring that natural hand
motions are used to operate equipment.
The drive for safety and efficiency areintegrated.
Not only does the manufacturer look
at drilling as the sole function of an
operator. A multi-skilled operator may
also manage drilling consumables, com-
plete basic maintenance and repor t de-
tails of bench conditions. These new
roles also must be designed into the ma-
chine interfaces.
Also with regard to improved ergo-
nomics and safety, Drilling Solutions
engineers work to design systems that
eliminate or reduce the hazards. In the
late 1990s when the United States Miningand Safety Administration imposed stric-
ter silica exposure limits for operators,
engineers found that improved air qu-
ality could not be achieved without re-
moving the concentration levels in cer-
tain applications. The drive then became
to manage the dust rather than improve
air quality through expensive filtration.
The goal of Drilling Solutions is to al-
low the operator to do what comes na-
turally and to create a work environ-
ment that provides superior comfortand safety.
Operator cabins andmachine interfaces
A rotary drill is recognized as one of
two pieces of surface mining equipment
that sits and works in its waste, heat and
dust. The other piece is the shovel or ex-
cavator. The operators cabin, or cab, is
the device used to protect the operator,
a design factor not seriously considered
as late as 1995.
Nearly everyone would agree todays
automobiles are safer, quieter, offer asmoother drive and are very user fri-
endly. The automobile is becoming the
acceptable standard in industry when
looking at operator cabins. The visual
look of an operator cab has also become
a design criteria, as personnel equate past
operator cabs with a metal box that
induces high fatigue. An automotives
structure and safety systems keep
passengers safe. Likewise todays drills
are engineered to protect an opera-
tor against hazards that once injured orkilled operators.
Reference dust management improvement.
Ergonomics and safety
Machinedevelopments ina new decadeErgonomics today has taken on abroader meaning with the adventof safer work rules, higher workefficiencies and superior designtools. Today engineers can studyand design machines that are effi-cient to operate, maintain, buildand transport. Engineering tools,new materials, improved indus-try standards and new technol-ogy allow a designer to model amachine and actually simulateoperation under safer operatingconditions. During this decade not much haschanged with the technical perfor-mance of drilling as cutting struc-tures remain the same. Rather thedesign emphasis has been on effi-ciency, fewer accidents and easeof operation. Globalization of mi-ning to a higher level is also driv-ing changes. The HIV epidemic inAfrica is reducing the workforce atan unheard of rate. New depositsin arctic regions require a newemphasis. This article highlightsthe advances Atlas Copco DrillingSolutions engineers have made tomeet these new challenges.
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12 BLASTHOLE DRILLING IN OPEN PIT MINING
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The image above shows a rock fall
that the operator survived without in-
jury. Using proper de sign techniques
and better materials. Atlas Copco en-
gineers have delivered an operator cab
that reduces interior noise levels signif-icantly below the industry benchmark
of 80 dBA. For example, the Pit Viper
351 with 1500 hp was measured below
70 dBA when drilling.
Like automotive climate control sys-
tems are developed to maintain opera-tor comfort more efficiently, todays
systems direct the cooling effort on the
operator. The systems are also used to
defrost windows in cold weather cli-
mates just as automobiles do. Drilling
Solutions engineers also are working to
advance the cleanliness of the air the
operator breathes.
Engineers can use computer models
to quickly improve line of site. Cabs
now feature more window space, which
improves visibility, due to glass and in-sulation technology. Camera technology
allows an operator to watch the areas
where visibility is restricted. The com-
bined effect is to give operators a full
view from the operators chair.
The operator chair and flooring play
active roles in reducing drilling vibra-
tions, which add to operator fatigue.
Now an operators chair is often referred
to as an operators pod, and is adjust-
able to fit a variety of shapes, sizes and
weights. All machine interfaces are now
within the operators reach.
Technology can also play a role in
protecting the operator from dangerous
work conditions. Drilling Solutions en-
gineers, working with suppliers, are
creating a system that allows limits of
operation to be defined and to give
an operator feedback when an unsafe
condition exists. As drilling conditionschange within the pit, the machine can
be easily reprogrammed to fit the new
situation.
The result of this combined effort
is to deliver a safe, comfortable work
environment that is suited for the long
shifts required in surface mining.
Maintenance ergonomics
Nearly unheard of a decade ago, in-
dustry standards now require safe, rou-
tine and easy access to all maintenance
points. In the 1990s the Australian New
South Wales MDG-15 Act gave guide-
lines for maintenance ergonomics that
have become the accepted standard in
industry today, and these standards, in
addition to factors such as fatigue and
safety, drive the machine design effort.
For example, Australian studies sho-
wed a very high incident rate for person-
nel getting on and off machines. These
results drove the international market to
look at alternatives. As a result, place-ment of key maintenance points could
only be in a zone from waist to shoul-
ders, based on measurements for 90
percent of the population. Until fairly
recently, operator comfort and safety
were only afterthoughts if they were
considered at all. Now, what was once
out of sight, out of mind, is a critical
requirement at the forefront of design
innovation.
John Stinson
Operator survived rock fall.
Comfort combined with ease of operation in one
package.
The image shows digital readouts of weighton bit, rotation speed, torque and rate of
penetration. It also can be programmed to
give an operator visual feedback.
The image shows a digital leveling device
on which the background can change colors,
sound an alarm or remove power when an
unsafe angle of operation isexperienced.
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BLASTHOLE DRILLING IN OPEN PIT MINING 13
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Mining safety
Since the implementation of the Mining
Safety and Health Act of 1977, a lot has
changed in the past 33 years. More spe-
cifically, a lot of lives have changed or
been saved. Safety is the obligation of
every single individual in every single
step of the entire mining process.
As taught in the MSHA training
class SLAM Risks (Stop Look
Analyze and Manage) helps us dimin-
ish workplace risks. SLAM was initiat-
ed to focus the mining industry on the
human factors in accident prevention.At Drilling Solutions, risk assessments
and design simulations are involved
in mitigating risks to the operator and
maintenance personnel. We should
con-stantly be assessing our surround-
ing environment and risks that might
be involved. It is something that we
should consider in every action we take
on a daily basis, from climbing off the
machine, to walking out through the
parking lot, to driving home that even-
ing, to walking in that front door; safeand sound and fully intact.
In order to facilitate what we should
be doing on a daily basis versus what
we actually do, this is a niche where we
as the OEM are able to further develop
safety into our products. We at Atlas
Copco Drilling Solutions have spent the
past year researching different scena-
rios and situations to find areas that
can further enhance the safety of per-
forming a specific function or task.
We have conducted open-floor meet-
ings with major mining corporations,
spent time on a wide-range of different
mining sites, and coordinated with
various teams world wide in order tofully understand develop, and offer you
a multitude of Personnel Rig Protection
opportunities for your machines. Our
ultimate aim is to lead the industry by
changing equipment designs to mini-
mize the risk to all par ties involved in
the mining process.
Tower access restraintsystem
This option provides the mine with adedicated resource providing a safe
means of conducting maintenance in
our towers. The Tower Access Restraint
System meets OSHA Standards 1926
and 1910, as well as Australian and New
Zealand Standards 1891.2:2001.
Drilling Solutions engineers have
designed a set of stairs for access to the
Tower while in the horizontal position.
Each step is made of sturdy steel grat-
ing, with an added slip-resistant grip
strut. The Stairway also consists of a
signed gate at the bottom, as well as
the top of the stairs in order to prevent
accidental entry. There is a continuous
handrail that goes up both sides of thestairway and then a spacious work plat-
form once you reach the top.
Once you have reached the top and
you are ready to enter the tower to per-
form maintenance, you open the gate,
clip onto each of the shuttles that are
attached to two stainless steel cables
that run the length of the Tower. The
cables are permanently anchored to
the Tower cords and include a shut-
tle on each side on which to hook the
harness. These shuttles are an integralpart of the st ructure and include a
The safest place to be is the cabin of the drill rig.
Personnel rig protection
Built-in safetyfeaturesFor drillers, the safest place tobe is the cabin of the drill rig.Our equipment has many built-in features and options that helpto increase operator safety suchas ROPS and FOPS protection.Moreover todays cabins are alldesigned with smooth edgesand without protruding com-ponents that could conceivablyinjure an operator who omits towear a hardhat. But the fact is,
the moment the operator stepsoutside, he or she is immediatelyexposed to dangers. Over theyears, technological advanceshave done a great deal to reducethe number of accidents and inju-ries. Atlas Copco is committedto this task and will continue toidentify risks and improve safetythrough our product design.
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14 BLASTHOLE DRILLING IN OPEN PIT MINING
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double-locking mechanism for safety
purposes and are specially designed to
withstand the vigors of a mining envi-
ronment. They also allow the opera-
tor full access to the Tower, as well
as being able to smoothly move over
transition pieces without the hazardous
practice of having to unhook from the
cable, allowing the individual to keep
their hands free for tools and the task
at hand.
In addition to the Tower Access Re-
straint System, the bottom of the Tower
is also filled with fiberglass grate deck-
ing. This is a continuous slip-resistant
and sturdy surface for the individual to
stand on while performing their duties.
The final result of combining the
above components is a safe and secure
tool to utilize during regular Tower ser-vice intervals. In addition, this system
provides improved safety and mobility
for mine personnel.
Access and egress
A lot of emphasis and design hours
went into the multiple options we now
provide for getting on and off the ma-
chine, always keeping ease and safety
in mind. Atlas Copco now provides a
number of different means to access
the deck and cab on the cab side of the
machine. These include your Standard
Ladder, a Hydraulic Ramp, a Hydraulic
Ladder, and Hydraulic Stairs. Each in-
dividual step on the above ladders
is comprised of either sturdy, slip-
resistant steel or fiberglass g rating.
One more added benefit to some of the
ladders mentioned is the safety inter-
lock that is built into the RCS control
system. This interlock will not allow
the rig to move while the ladder is in
the down position.Some of the above options are obvi-
ously more intricate than the Standard
Ladder, but they do provide a more nat-
ural means of accessing the machine.
They can allow the operator or main-
tenance personnel an easy approach
onto the machine, opposed to having to
hoist themself up a vertical ladder. This
ease enables hands to be free for other
needs, such as carrying tools. Even
more so, the Hydraulic Ramp that we
offer provides a flat surface that, can beutilized as an easy surface for dollies to
be pulled up and, for example loaded
down with a bucket of grease.
When you need to climb on the ma-
chine from the non-cab side you can
either have a Standard Ladder or no lad-
der at all with a handrail in its place.
And in the event of an emergency we
now also offer one or two Emergency
Ladders on the Non-Drill end of the
machine. These ladders flip out with a
quick release and provide a swift means
of escape if need be. When they are not
in use they fold up onto the rig and re-
latch.
The main emphasis of these new
ladder options is not for aesthetics, but
instead to fur ther ensure that there is
a safe means of getting on and off the
rig. The new options above allow for
front or backwards ascent or descentfrom the machine. We want to try to
get away from having to climb on the
rig, but rather be able to easily access
the decking in a more natural form.
Decking
A main concern of all mines is working
in a confined space. Drilling Solutions
is currently exploring the balance of
opening up workable areas as well as
keeping the machines overall size in
mind for transportation purposes and
still allowing the mine to access those
holes that might bring an operator close
to the highwalls.
We have developed options that will
allow complete 360 access around the
machine. This includes an option for
complete walk-around access of the
cab. This added selection can be used
for inspection and for cleaning the win-
dows for further visibility.
Another part of the 360 access is
a decking option that includes a builtin bit basket on the Drill-End of the
machine. By adding this decking op-
tion, you not only gain complete access
to the machine, but also have a safe,
secure, and dedicated spot to store bits
and hammers. This option inhibits bits
from being laid unsecured on the deck,
opening up a possibility for them to
shift and move during tramming.
One more part of the 360 access
option that is available is an Extended
Cooler decking. Prior to this optionthe only way to access the back of
PV-270 tower access stairs.
(Part of tower fall restraint system)
Tower fall restraint system with infill.
Hydraulic ladder option.
PV-230 standard ladder option.
PV-230 spring assisted ladder option.
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the coolers was by using a man-lift or
some other similar means. By adding
on this decking you add approximately
2 feet (61 cm) to the non-cab side of
the machine. This allows unconstrained
access to the back of the coolers for
cleaning, maintenance or a walkway
to other areas of the machine.
Energy isolation
When working on any piece of machin-
ery this size, there is the constant con-
cern about isolating any energy, whe-
ther it be electrical, hydraulic, or pneu-
matic. The engineers at Drilling Solu-
tions spend numerous hours designing
and configuring different options with
the goal of being able to give anyone
with access to the machine a safe andsecure piece of equipment to work on,
complete with fail-safes when applica-
ble. We know that the easier we make
the machine to work on, the happier
and safer all entities involved will be.
One of the new options offered is a
Ground-Level Battery and Starter Iso-
lation box. Inside this box are lockable
turn switches that either engage or dis-
engage the power or the starter. There
are also long-life LED lights that are
color coded to designate whether it isreceiving power, or if the power is off.
The front cover on this box is comprised
of a strong plexiglass piece so that you
can see what energy state the machine
is in without having to physically open
the front cover. Again we are of the
mindset that the quicker and easier it is
to use, the more it will be used.
Another example of how we are iso-
lating hydraulic energy is by utilizing
a series of Hydrau-Flo Valves. These
valves are specially designed to prevent
fuel spillage, in the event of over-fillingor tank rupture. Not only is this design
a safe way to transfer fuel, but it is also
environmentally friendly.
Ease of maintenance
There are many new options offered
straight from the factory that have
greatly enhanced the ease of working on
our machines. Keeping confined spa-
ces in mind, as well as the idea that the
less often a component needs to be ser-viced, the more production the machine
does in the dirt. When you choose the
above option for cooler access decking,
you also then have the opportunity to
pick the Cooler Access Ladder. The
Cooler Access Ladder is a stepladder
integrated onto the decking and hand
railing that provides a safe approach to
accessing the radiator tank on top of the
cooler for filling, checking, or mainte-
nance. As a side note pressure-relief
safety caps are standard on all machine
radiator tanks. These caps allow the
pressure that naturally builds up in the
tank to safely be released without the
danger of spraying out hot coolant onto
the individual.
In regards to the powerpack, we now
offer a dipstick for the gearbox. Prior
to this the sight glass for the gearbox
was in a hard to see area. Now it is easyto access and it provides a means to ea-
sily check the gearbox oil level daily
or as required. We also have the new
Oil-Centrifuge option that doubles the
life of the engine oil. It achieves this
without filters to change or clean.
We are providing new ground le-
vel service options in addition to the
Ground-Level Battery and Starter
Isolation. The first of these is a new
ground level Live-Oil Sampling option.
This option provides the ability to takesamples for Hydraulic Oil, Engine Oil,
and Compressor Oil. The oil continu-
ally circulates through this area so that
all samples taken are fresh.
Two more ground level service
options that are available are the Quick-
Fill Box and the Quick-Drain Box.
These two boxes located on the non-drill
end of the rig provide asimple means to
either fill or drain the machine of its
fluids. Each connection point is clearly
labeled and consists of a safe quick
connect, each differing in size to avoidcross contamination of fluids.
Design teams at Atlas Copco are
constantly getting feedback from cus-
tomers or our own field service person-
nel. They let us know if something is
working great, what can be improved,
or if something needs to be completely
redesigned. One of the steps that we
are taking as a company is trying to
phase out weld ing, and instead use
bolt-in par ts. This facilitates in both
making it easier to change out partsand cuts down on possibly challenging
PV-270 new decking and access options.
PV-230 bit basket option.
(Will be located on drum deck)
PV-270 ground level battery and starter
isolation.
PV-270 overview of location of live sampling
quickfill and quick drain.
From left: Close up view of live sampling,
quickfill and quick drain.
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16 BLASTHOLE DRILLING IN OPEN PIT MINING
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the integrity of the material by weld-
ing and cutting. As an added bonus, the
more components that we design to bebolted in rather than welded results in
a more modular machine that can be
customized specifically to the custom-
ers orders.
One of these newly redesigned bolt-
in options is the sheave and cable
retainers that are on the PV-270 and
PV-351 towers. Previously, when it was
time to change out the cables, these pins
and sheaves had to be removed. Now it
is just a matter of loosening a few bolts,
changing out the cable, and reboltingthe roller back in. Another design that
has been modified is the feed cylinder
supports on the PV-351s. Again it
used to be that you would have toremove the feed cylinders to replace
the worn guides. The guides now bolt-
in as well. By constantly keeping ease
of maintenance in mind, Atlas Copco
Drilling Solutions are hopeful that it
will result in more productivity hours
for you and your mine; less down time
means more drilling time.
Regardless of what drilling rig you
may own, or what piece of equipment
you may work on, we here at Atlas
Copco Drilling Solutions want youto always be conscious of your every
action on or around the mine site.
Mining is not the safest in-dustry out
there, but with everyone putting forth alittle more effort towards always think-
ing SAFETY FIRST we feel that this
will make a monumental difference
in everyones life. As long as you do
your part of ensuring that you are con-
stantly thinking of your safety, you can
rest assured that Atlas Copco Drilling
Solutions will do all within its power
when designing a machine to keep you
just as safe.
Maureen Bohac
Options PV-270
SEOH*
PV-270
RCS
PV-230
SEOH
PV-230
RCS
PV-351 DML DM45 DM30
Hydraulic Hedweld Ladder
Hedweld Spring Ladder
Atlas Copco Hydraulic Ladder
Emergency Ladders
New Cab
Tower Access
Cable Reel
Additional Tower Rest Water Tank
Tropical Engine Roof
Stainless Steel Battery Boxes
Staniless Steel Electrical Boxes
Ground Level Battery Isolation & Jumpstart
Live Sampling
Under the Deck Misting
Secondary Rod Catcher
Autcrane Option
Wormald Fire Suppression
Drum Deck Bit Holder
Protective Hose Sleeving
Dynaset Water Injection Pump
Secondary Air Conditioning Unit
Buddy Seat With Seatbelt
Cooler (Radiator Tank) Access
Engraved Hydraulic Schematic
Centrifuge Engine Oil Filter
Gearbox Dipstick
Hydra-Flow Fuel System
360 Walk-Around Decking
Housing Option
Quick Fill Box
Quick Drain Box
*SEOH = Non RCS, Standard Electric Over Hydraulic
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BLASTHOLE DRILLING IN OPEN PIT MINING 17
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An increasing demand
Today, the population of the world
stands at about 6.5 billion people. In
simple terms, this means that every
year approximately 10 tons of material
is extracted using surface mining tech-
niques for every person in the world.If one looks to the future, the UN esti-
mates that in 20 years (2038) the worlds
population will have reached about 8.5
bil lion people. By simply applying
the current utilization rate of 10 tons/
person, one would expect the amount
of material extracted yearly by surface
mining techniques to climb to 85 billion
tons. One must keep in mind, however,
that today about 95% of the population
growth is in the developing countries
of the world. Based on their expecta-tions for improved living standards
in the future, the actual estimate of ma-
terials mined using surface mining tech-
niques in the year 2038 is 138 billion
tons (Bagherpour et al, 2007).
The ability of the earth to meet this
type of demand is not really a question
of resources, since they are clearly
there, but rather a matter of price and
cost. In looking at the mineral resource
base, one must conclude that, in gener-
al, the mining conditions will be sign-ificantly more difficult than today. In
addition, ever-increasing environmen-
tal and health and safety conditions are
expected to be in place. This means that
the entire mining process from pro-
specting to exploration to development
to extraction and finally to reclama-
tion will have to become much more
advanced. In many places of the world
today, mine closure must be fully and
satisfactorily addressed before a surface
mine can be opened. This translatesinto requirements for applying first rate
engineering and technology for meet-
ing todays requirements and especially
those of the future. Atlas Copco is at
the forefront in producing the equip-
ment and technologies required today
and for addressing the challenges of the
future.
A brief synopsis ofquarrying and open pit
miningThis introductory chapter wil l focus
on those surface deposits that require
the application of drilling and blasting
techniques as part of the overall extrac-
tion process. Excluded from the discus-
sion will be strip mining, the mining of
sand and gravel deposits and the quar-
rying of dimension stone.
As indicated, large quantities of raw
materials are produced in various types
of surface operations. Where the pro-duct is rock, the operations are known
Photo: Copper mine in the southwest USA.
An introduction to surface mining
The wealthof nationsA well-accepted principle is thatthe wealth of a nation comes fromthe earth. In the world of mining, acorollary to this is that If it cantbe grown, it must be mined.Surface mining techniques are theprincipal means used to extractminerals from the earth. Theyearly rock production yieldingmetals, non-metals and coal in theworld totals 16.6 billion tons*. Ofthis, the production from surface
mines is about 70% or 11.5 bil-lion tons. Crushed rock, sand andgravel - the fundamental materi-als required for construction - arelargely produced using surfacemining techniques. Their yearlyproduction rate totals 23.5 billiontons. To this must be added thematerials needed for the produc-tion of cement, another 2.3 billiontons. Finally, the amount of wastethat must be moved in the processof extracting the valuable materi-als is estimated at 30 billion tons.Summing, one finds that the total
amount of material extracted peryear using surface mining tech-niques is of the order of 67.3 bil-lion tons (Bagherpour et al, 2007).* 1 ton = 907 kg
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18 BLASTHOLE DRILLING IN OPEN PIT MINING
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as quarries. Where metallic ore or non-
metallic minerals are involved, they are
called open pit mines. There are many
common parameters both in design and
in the choice of equipment.
When examining a deposit for poten-
tial mining and even when expanding
a current operation, one often employs
a process called circular analysis. As
shown diagrammatically in Figure 1,
the process consists of five components.
Although the figure applies specifically
for the open pit mining of ore depos-
its, a similar procedure is followed for
quarries.
One naturally begins with a descrip-
tion of the deposit and using some as-
sumed costs a preliminary pit design
is obtained. By adding the desired pro-
duction rate into the model a production
schedule is generated.Based on the
schedule, one determines the required
equipment fleet, staffing, etc. to satisfy
the schedule. This leads allows one
to calculate the capital requirements
and the operating costs. With these
now-estimated rather than assumed
costs, the ore reserves are re-examined
and design alternatives evaluated.
Eventually, an overall financial evalu-
ation is performed. The double-headed
arrows indicate the highly repetitive
nature of the process.
Quarries
A rather simple but useful definition of
a quarry is a factory that converts solidbedrock into crushed stone. Quarries
can be either of the common pit type
or, in mountainous terrain, the hillside
type. Pit type quarries are opened up
below the level of surrounding ter-
rain and accessed by means of ramps
(Figure 2). The excavation is often split
into several benches depending on the
minable depth of the deposit. When the
terrain is rough and bulldozers cannot
provide a flat floor, a top-hammer con-
struction type drill rig can be used to
establish the first bench. Once the first
bench is prepared, production drilling
is preferably carried out using DTH- or
COPROD techniques.
The excavated rock is crushed, scre-
ened, washed and separated into differ-
ent size fract ions, for subsequent sale
and use. The amount of fines should be
kept to a minimum. Not all types of rock
are suitable as raw material for crushed
stone. The material must have certain
strength and hardness characteristics
and the individual pieces should havea defined shape with a rough surface.
Igneous rock such as granite and basalt
as well as metamorphic rock such as
gneiss are well suited for these purposes.
Soft sedimentary rock and materials
which break into f lat, flaky pieces are
generally unacceptable. The final prod-
ucts are used as raw material for chemi-
cal plants (such as limestone for cement
manufacturing, the paper and steel
industries), building products, and for
concrete aggregates, highway construc-tion, or other civil engineering projects.
Financialoptimization
1. Capital and operating
summation
2. Revenue
3. Cash flow statement
4. Marginal ore utilization
5. Rate of return
Ore reserveanalysis
1. Break-even analysis
2. Drill-hole evaluation
3. Pit design
4. Marginal analysis
Productionscheduling
1. Preproduction costs2. Working room
3. Stripping ratios
4. Sequencing
5. Reclamation
6. Operating schedules
7. Financial
8. Constraints
Equipment and
facilities1. Capital intensive
2. Equipment selection
3. Operating costs
4. Capital depreciation
5. selective mining
Refined orereserves
1. Cutoff grade
2. Marginal analysis
3. Design alternatives
Figure 1. Financial optimization using circular analysis (Dohm, 1979).
Figure 2. A diagrammatic representation of a quarry operation.
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Quarries are often run by operators who
sell their products to nearby contractors
and road administrators. Because the
products are generally of relatively low
value, they are transport cost sensitive.
Hence, wherever possible, quarries are
discreetly located as close as feasible to
the market. Special measures are requi-
red to minimize adverse environmental
impacts such as noise from drilling,
vibrations from blasting, and dust from
crushing and screening to the neighbor-
ing areas.
Open pit mines
Two major differences between open pit
mining and quarries are the geological
conditions and the demands placed
on the characteristics of the blastedmaterial. For quarries, a majority of
the rock products eventually delivered
to the customers has only undergone
crushing and screening in order to ob-
tain the desired size fractions. An open
pit meta l mine, on the other hand,
attempts to deliver the ore as pure as
possible via crushers to a concentrator
consisting of mills, separators, flota-
tion and/or biochemical systems, etc.
The resulting concentrates/products
are eventually sent for further process-
ing before emerging as a final product.
For certain metals, this latter process
involves smelting and refining. The
deposits mined using open pit meth-
ods have a variety of sizes, shapes and
orientations. Sometimes the distinction
between the valuable material and the
waste is sharp such as shown in Figure
3 and in other cases the distinction
is more subtle - based upon econom-
ics. As in quarries, the minerals are
extracted using a series of benches. If
the orebody does not outcrop, the over-lying material must first be stripped
away to expose the ore. As the initial
pit is deepened, it is widened. The pit
geometry is controlled by a number of
factors including orebody shape, grade
distribution, the stability of the slopes,
the need to provide access, operating
considerations, etc.
For the geometry shown in Figure
3, a significant amount of waste must
be removed (str ipped) to access the
next bench of ore at the pit bottom.Without jeopardizing slope stability, it
is of prime importance to keep the pit
slope angle as steep as possible, thereby
keeping the excavated waste to a mini-
mum. There becomes a point where the
quality of the material contained in the
next ore bench is not sufficiently high
to pay the costs of the associated waste.
At this point in time either the open
pit mine closes or, if condit ions are
favorable, continuation may proceed us-
ing some type of underground method.
Figure 4 shows the Aitik copper/gold
mine in northern Sweden. It is Europes
largest copper mine producing 18 Mton
of ore per year. Currently at a depth of
480 m it is expected to reach of depth
of 800 m before decommissioning. The
Bingham Canyon mine in Utah (Figure 5)
Figure 4. The Aitik mine in northern Sweden (www.boliden.com).
Oreb
ody
Waste
Good fragmentation needed
Good slope stability
Pit slope 45o
Benchslope 72o
Figure 3. General principles of open pit mining.
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20 BLASTHOLE DRILLING IN OPEN PIT MINING
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has been in production since 1906 and
is one of the largest man-made struc-tures in the world, measuring 1200 m
deep and 4400 m across the top. It
has produced more copper than anyother mine in history and has many years remaining. With respect to waste
removal, the fragmentation demands
are simple. Since, the material is not
required to pass through a crusher, the
maximum size is controlled by the li-
mitations imposed by the equipment
used to load and haul the material to
the waste dump. On the other hand,
good fragmentation of the blasted ore
offers great savings in the total costs of
the mineral dressing process.
Some forward thinking
Extraction of the valuable mineral whe-
ther in quarries or open pits requires a
number of unit operations. Generally,
the rock is drilled, blasted, loaded,
hauled to a primary crusher and then
transported further to a plant of some
type for further processing. Figure 6
shows a schematic of the process.
Often, mines are organized so that
the individual unit operations are se-
parate cost centers. Although there areadvantages to this approach, one result,Photo: Blasthole drilling of 40 ft (12 m) benches at Newmont's Phoenix mine, Nevada, USA. See page 91.
Drilling
Blasting
Loading
Hauling
Primary crushing
Secondary crushing
Grinding
Mine
Orebody
Further treatment
Overallfragmentationsystem
Mill
Figure 6. Diagrammatic representation of the
overall mine-mill fragmentation system and the
mine and mill subsystems (Hustrulid, 1999).
Figure 5. The Bingham Canyon copper mine near Salt Lake City, Utah, USA. (www.kennecott.com)
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BLASTHOLE DRILLING IN OPEN PIT MINING 21
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unfortunately, can be that the individual
managers look at minimizing the cost
of their center rather than on the overall
objective of overall cost minimization.
In reviewing the components in Figure
6, it can be shown that they can be
replaced by two operations, fragmen-
tation and transport. In the simplified
view shown in Figure 7, there are five
different stages of fragmentation each
with a different energy product pro-
file.
One must carefully examine the bestopportunities for applying fragmenta-
tion energy in the various stages on
the final product cost. For example, in-
creased fragmentation energy can be
relatively easily introduced in the mine
by modifying the dr ill pat terns and
explosive characteristics. This action
may provide an inexpensive alternative
to adding the fragmentation energy in
the grinding circuit. This process of
considering all elements of the frag-
mentation system, logically dubbedmine-to-mill is a recognized part of
mine-mill optimization. In addition
to production, there are some other
important customers for blast engi-
neering.One is termed the Internal
Environment and the other the Ex-
ternal Environment. These are shown
in Figure 8.
Both for safety and economic rea-
sons, it is important to preserve the
integrity of the pit wall. Large diam-
eter blast holes, energetic explosives
and wide patterns will be used in the
production blasts which will be subse-quently loaded out using large excava-
tors and haulage units. Near the pit wall,
much more precise techniques involving
smaller diameter holes, specially de-
signed explosives, and special timing
procedures are employed to minimize
wall damage (Figure 9). Unless great
care is taken, large loading equipment
can easily spoil the results of the trim
blasting. The result is that special loa-
ding and hauling fleets may be requi-
red. Failure to protect the pit walls,translates into the need for flatter slopes
and additional waste removal and/or the
loss of reserves. These, in turn, translate
into higher overall costs for the mining
operation. In carrying out an evaluation
of the appropriate drilling and blasting
practices, emphasizing mine-to-mill
aspects without taking into account
the care of the slopes can result in lo-
wer production costs but at the sake of
higher investment (capital) costs due
to greater stripping or lost reserves.
Therefore care must be taken to include
all the costs when making the analysis.The external environment component
falls into the category of a potential
show-stopper since if proper meas-
ures are not taken to fully comply with
standards, the operation could very well
be shut down.
Final remarks
Atlas Copco has the advantage of long
experience in all types of surface drill-
ing operations, with a product range tomatch. With its history of innovative
DrillingSpecified Drill Pattern
External environmentMinimum: Flyrock, noise,
airblast, ground vibration
Loading & HaulageGood: Fragmentation,
Pile shape, diggability
Primary crusher
High throughput andbridging preventation
Secondary
crushing & grindingEfficient crushing and
grinding feed
Internal environmentMinimum wall damage Blast Engineering
Drilling
Blasting
Loading & Haulage
Primary crushing
Conveyor
Secondary crushing
Grinding
Insitu
Further treatment
Fragmentation
Transport
Figure 7. The mine-mill system represented as
fragmentation and transport unit operations
(Hustrulid, 1999).
Figure 8. Simplified view of the five different stages of fragmentation, each with a different energy -
product profile.
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22 BLASTHOLE DRILLING IN OPEN PIT MINING
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ReferencesBagherpour, R., and Tudeshki, H.
2007.Material handling in world-
wide surface mines. Aggregates
International. Pp 10-14. June.
Dohm, G.C., Jr. 1979.Circular ana-
lysis Open pit optimization.
Chapter 21 in Open Pit Mine Plan-
ning and Design (J.T. Crawford, III
and William A. Hustrulid, editors).
AIME. Pp 281-310.
Hustrulid, William. 1999.Blasting
Principle s for Open Pit Mining.
A.A. Balkema, Rotterdam.
Fernberg, Hans 2002,New trends in
open pits, Mining and Construction
1-20