Drilling WorkshopRoy Rathner and Arne Lislerud

� Pit-to-Product

� Mine-to-Mill

� Mine-to-Metal

=> requires a overview of operations, technology a nd markets

Optimisation of quarrying

Overview of basic topics

� end-product volumes

� costs

� pricing

� stockpiling

=> right mix of all issues?

Mgt.

Plant SalesPit

Organisation

Technology

Market analysis

� key financial performance in a period

� overall quarry profitability

� capital employed(especially unscheduled stockpiling)

� key production performance in a period

� end-product tonnages, costs and margins

� productivity and cost per machine

� safety in operations

� public relations

Key quarry performance indicators, KPI’s

How drilling and blasting affectdownstream operations

� sizing drill patterns� drilling accuracy

� boulder downtime� crushing capacities� power consumption� production of fines

and waste

� field performanceof explosives

� shotrock fragmentation���� boulders���� floor humps���� fines and fragment

microfractures� muckpile profiles & swell

� loadability andloading capacities

� selectivity inmining & industrialmineral operations

Drilling Loading CrushingBlasting

Rock drillability versus strength

300300300300

200200200200

100100100100

Uni

axia

l Com

pres

sive

Str

engt

h, U

CS

(M

Pa)

Greenstone

Greenschist

Limestone

Marble

Calcerous Shale

Quartzite

Sandstone

SiltstonePhyllite Mica schist

Mica gneiss

Coarsegrainedgranite

Medium grained granite

Shale

20202020 30303030 40404040 50505050 60606060 70707070 80808080 90909090 100100100100

300300300300

200200200200

100100100100

300300300300

200200200200

100100100100

300300300300

200200200200

100100100100

20202020 30303030 40404040 50505050 60606060 70707070 80808080 90909090 100100100100

20202020 30303030 40404040 50505050 60606060 70707070 80808080 90909090 10010010010020202020 30303030 40404040 50505050 60606060 70707070 80808080 90909090 100100100100

Drilling Rate Index, DRI

Gabbro

Quality feed – handling boulders

� boulder count dependent on primary crusher opening (and to a lesser extent primary crusher capacity)

� sort boulders from muck pile

� downsize boulders before entering primary crusher

� minimise boulder count using reduced uncharged heigh t and/or tighter drill patterns

Quality feed – effect of micro-fracturing

Rock type Anorthosite

Explosive Slurrit 50-10

Test blasts 4 x 50 000 tonnes

Bench height 11 m

70Hole diameter, d (mm)

80 90 110100 120

35

30

25

20

40

Per

cent

age

of 0

-32

(mm

)

Ø76

Ø89 Ø102

Ø115

Large SUB’ from prior bench level

0 - 300 mm

0 - 32 mm

Belt weights

Feed

0 - 70 mm

32 - 64 mm

0 - 950 mm

� equipment flexibility and reliability

� D&B as to aggregate production requirements

� ability to handle difficult ground conditions

� availability of local / on-call field service

Quarries and D&B contractors

� annual production requirements in bm3 or t => numbe r of drills

� critical diameter of explosives => hole size big eno ugh?

� flexibility in usage => different types of work

� application costing => D&B costs per t

� operator training and support

� operator comfort and safety

� ease of transport between pits

Criteria for selecting drills

Drill-hole diameter (mm)100 200 300

D&

B c

osts

(€/

t)

50 100 15020070 300400

10

7

5

70

15

2025

50

30

Dril

l pat

tern

, SB

(m

2 )

Better blastability

Finer

100

50 100 15020070 300400

10

7

5

70

15

2025

50

30

Drill-hole diameter, d (mm)

Finer fragmentation

100

Better blastability

Annual drill rig production capacities

Drill-hole size, mm

512”

642.5”

763”

893.5”

1024”

Ann

ual p

rodu

ctio

n, M

tpa

0.4

1.2

2.0

2.8

1154.5”

0.8

1.6

2.4

1275”

Panteras - DPRangers - DXCHA’s - DC

� shifts per year 225 = 5 d/w · 45 w/a� shift hours per year 1800 = 8 h/d · 5 d/w · 45 w/a� engine hours per year 1224 = 1800 · 68 % utilisation� rock density, t/m 3 2.7

� work related accidents for:

���� mobile equipment

���� hazardous work areas

� emissions control

� noise control

� dust control

� flyrock / charging / straight-hole drilling

� falling rocks / wall control

=> safety is linked as much to equipment as it is to attitudes

=> health, safety and environmental issues are eve ryone’s concern

=> the ultimate safety target is zero harm – not jus t a minimum occurrence of accidents

Occupational health and safety

Assessment of some work relatedhealth risks

RadonNoise

Oil mist Vibrations

Diesel

Silicosis Stress/mental workload

Musculoskeletal disorders

1950 1960 1970 1980 1990 2000 2010

Risk

� unwanted incidences do not just happen – they have r oot causes

� actions can be taken so as to reduce frequency and consequences of unwanted occurrences

� the relationship between complexity and knowledge i n the workforce is often unbalanced –e.g. operator hazard training is a must!

Safety of inpit operations

Premature ignition of electric detonators and blast due to lightning

Pit wall failure burying 3 drill rigs in rubble

� new equipment requirements for the future?

Safety of inpit operations

Rollover from terrain bench - 35m drop

Rock fall source area

Manditory 20m personnel exclusion zone from highwall ?

Mina AlumbreraDouble bench presplitting

Mina AlumbreraPitwall scanlines

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