Blasthole Reference book

7/22/2019 Blasthole Reference book www.genborneo.com.pdf

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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

[email protected]

Foreword


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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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.


11/248


TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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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TALKING TECHNICALLY

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

Blasthole Reference book

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