SHORT HOLES :SHORT HOLES :diameter < 52 mmdiameter < 52 mmlength < 5 mlength < 5 m

advantages :advantages : allow to follow the irregularallow to follow the irregularore/waste contact in weakore/waste contact in weakformationsformations

disadvantages :disadvantages : low productivity, high costlow productivity, high cost

Blast hole drilling

LONG HOLES :LONG HOLES :diameter up to 162 mmdiameter up to 162 mmlength up to 70 mlength up to 70 m

advantages :advantages : highhigh productivity, low costproductivity, low cost

disadvantages :disadvantages : application is limited to regular application is limited to regular or massive strong depositsor massive strong deposits

Drilling patterns for narrow vein deposits

Overhand or back stoping Breast stoping Frontal benching

w

h

l

l

h

w

h

wl

Cut-and-fill and Shrinkage Stoping

Cut-and-fill and Shrinkage Stoping

Undercut-and-fill Stoping

Production Jumbo

Drifting Jumbo

Drifting Jumbo

Hand-heldStoper drill

Hand-heldJack Leg drill

Hand-heldJack Leg drill

Hole depth,m

3 - 4

2 - 2.5

Drilling patterns for narrow vein deposits

Schéma de foration de la face du chantier partranches montantes remblayées

h

wl

Drilling patterns for flat dipping deposits

drifting downward benching

downward benching with 4 free facesfrontal benching with 4 free faces

downward benching with 3 free facesfrontal benching with 3 free faces

MANUAL DRILLINGMANUAL DRILLING

Short hole drilling

JUMBOSJUMBOS

Diameter : jusqu’à 82 mmLength : 15 mDownward drilling : 25 m/hourUpward drilling : 20 m/hour

TOP HAMMERTOP HAMMER

Diameter : 28-46 mmLength : 3 mJack-hammer : 12.5 m/hourStoper : 10 m/hour

Parallel drilling patterns for massive deposits

vertical slabbing horizontal slabbing

Fan drilling patterns for massive deposits

upward fan drilling downward fan drilling ring fan drilling

Beam pattern patterns for massive deposits

Crown pillar cavingCrown pillar caving

Long hole drilling

DOWN THE HOLE HAMMERDOWN THE HOLE HAMMER

DRILL RIGDRILL RIG

Diameter : up to 165 mmLength : 100 mDrilling speed : 15 (6-20) m/hour

Operating costs of drilling and blasting

oreofton/$,cs

C

T

LC

steel,bit

drilling

hour

round

round

drilling

where : Chour - hourly cost of the drilling equipment in $ per hour ;cbit,steel - bit and steel wear cost per meter drilled in $ per meter ,

cbit,steel 1 $/mTround - tonnage blasted per round in tonnes per round ;Lround - total holes length per round in m per round ;sdrilling - average drilling speed in m per hour :

Jumbo frontal stoping, breasting : sdrilling = 25 m/hourJumbo overhand stoping : sdrilling = 20 m/hourJack leg : sdrilling = 12.5 m/hourStoper : sdrilling = 10 m/hour

Cost estimation

Capital cost

Hourly operating cost

Operator labor

Parts

Maintenance labor

Diesel fuel

Electric power

Lube oil

Tires

Compressed air

Cost estimation

Parts, $/h

Labor, $/h Electricity, $/h

Lube, $/h Tires, $/h

Total, $/h

Jack-hammer 0,15 0,15 0 0,15 0 0,45Stoper drill 0,11 0,11 0 0,15 0 0,37QUASAR D3-E50 5,58 5,1 2,09 1,91 0,07 14,75MERCURY D4-E50 5,58 5,1 2,09 1,91 0,07 14,75MONOMATIC 5,58 5,1 2,09 1,91 0,07 14,75QUASAR 1L D3-E50 6,87 6,25 2,17 2,37 0,07 17,73

Hourly operating cost

Hole diameter, mm

Hole length, m

Drilling speed, m/h

Price, $ Hourly operating cost, $/h

Compressed air cost, $/h

Price 27-40 2-3,5 10-15 4884 0,45 2,2Marteau- stopeur 27-40 2-2,5 8-12 3784 0,37 2,7QUASAR D3-E50 35-41 3-4 15-25 333500 14,75 4,5MERCURY D4-E50 35-41 3-4 15-25 333500 14,75 4,5MONOMATIC 35-41 3-4 15-25 333500 14,75 4,5QUASAR 1L D3-E50 45-63 12-20 20-40 414330 17,73 6

Capital cost and technical characteristics

Operating cost of drilling and blasting : Tonnage blasted per round

meter,lhwTaverageround

where : w - stop width in m ;h - stop height in m ;l - stop length in m ;average - average rock masse density in tonne per m3 .

Operating costs of drilling and blasting : Total holes length per round

where : lhole - hole depth in meters ;N - number of holes per round, holes ;q - powder factor in kilograms of explosive per tonne of rock

broken ;Eh - charge of explosive per hole in kilograms ;Tround - tonnage of rock blasted per round in tonnes.

holes,Eh

qTroundN round

meters,NlLholeround

Theoretical powder factor

where : Rc - uniaxial compressive strength of the rock in MPa; C1 and C2 - empirical coefficients

3c210 m/kg,RCCq

C1 C2

Short holes 0.16 0.008Long holes -0.0448 0.0067

Corrected powder factor

543210I kkkkkqq

where : q0 - theoretical powder factor in kilograms of explosive per cubic meter of rock broken ;

k1 - is relative strength of explosive factork2 - is required fragmentation factork3 - is the hole diameter factork4 - free face condition factor is the factor taking in to account number and conditions of free facesk5 - drilling pattern factor taking into account increasing of the powder factor when the drilling pattern is different from parallel

Relative strength of explosive factor - k1

where : ABSref - absolute bulk strength of the reference explosive in J/cm3 or in cal/cm3

ABS - absolute bulk strength of new explosive in J/cm3 or in cal/cm3

AWSref - absolute weight strength of the reference explosive in J/gramme or in cal/gramme :

explosive of reference is the Extra dynamite : AWS = 1030 cal/gAWS - absolute weight strength of new used explosive in J/grammek1 = 1.13 for ANFO

AWS

AWSkor

ABS

ABSk ref

1ref

1

Relative strength of explosive factor - k1

Typical Properties of Extra Gelatine

Blend%Emulsion / %ANFO

100/0 80/20 70/30 60/40

Bulk Density (g/cc) 1-05-1.25 1.05-1.28 1.05-1.28 1.05-1.30VOD (m/s) 6000 5800 5800 5600Water Resistance Excellent Excellent Excellent ExcellentRelative WeightStrength (Effective)

101 106 110 114

Relative Bulk Strength(Effective)

150 159 168 176

Sleep Time (months) 2 2 2 2Minimum HoleDiameter, mm

75 75 75 75

Typical Properties for Emulsion and Emulsion/ANFO blends

Relative strength of explosive factor - k1

Typical Properties of UNIGEL Semi-Gelatin Nitroglycerine Dynamite

Typical Properties of DYNO RU Booster sensitive bulk emulsion

Required fragmentation factor - k2

1nf

2 b

lk

1k2 For short holes

For long holes

where : lf average distance between fractures in the rock masseb required average bloc size after blastingn1 = 0.5 to 0.6

Hole diameter factor - k3

Jumbo : d = 38 mmHend-held drill d = 32 mm

2n

ref3 d

dk

where : d - new hole diameter in mdref - diameter of reference in m

for short holes dref = 0.042 mfor long holes dref = 0.105 m

n2= 1 - in monolithic formation ;n2= 0.5 - in highly fractured formation

Free face condition factor - k4

k4 = 1.4 to 1.6 for a blast of short holes with a single free face perpendicular to holes axes

k4 = 1.2 to 1.3 if blasting of long holes is done on the broken rock masse

Broken material

Drilling pattern factor - k5

beam pattern : k5 = 1.3 to 1.5

Burde

nS

free face

open stope

broken ore

fan pattern :k5 = 1.1 to 1.2

parallel pattern (reference) :k5 = 1

Operating costs of drilling and blasting : unit hole depth

where : lhole - hole depth in meters ;fpull 0.92 - pull factor taking in to account the subdrilling ;z - stop size parallel to the hole, stop length for the breast or

frontal stoping and stop height for the overhand stoping ;

meters,f

zl

pull

hole

lhole

l

h

lhole

Operating costs of drilling and blasting : Charge of explosive per hole

where : Eh - charge of explosive per hole in kilograms ;lhole - hole depth in meters ;dhole - hole diameter in meters ; - of explosive loading density in kilograms per m3,

= 800 for ANFO ;fburden - burden factor, fburden 0.75 ;fp - factor taking in to account charge diameter compared with hole

diameter, fp = 1 for ANFO.

hole/kg,fl)fd(4

Ehbourdenhole

2

phole

Cost of blasting

where : p/ - corrected powder factor in kilograms of explosive per tonne of rock broken ;

cexplosive - cost of explosive in $ per kilogram , cexplosive = 0.6 $/kg for ANFO ;

ccap,primer - cost of caps and primers in $ per hole , ccap,primer 2.5 $/hole ;

N - number of holes per round .

brokentonne/$,T

NccpC

round

primer,cap

losiveexpblasting