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Page 1: SERVICES - TORQUE AFRICA · Air•Core•Drilling• • AIR•CORE•DRILLING•is•a•well-known•and•widely•used•method•when•it•comes•to•soft•rock•and•soil•

Reverse�Circulation�Drilling�

RC�DRILLING�is�a�method�of�drilling�which�uses�dual�wall�drill�rods�that�consist�of�an�outer�drill�rod�

with�an�inner�tube.�These�hollow�inner�tubes�allow�the�drill�cuttings�to�be�transported�back�to�the�

surface�in�a�continuous�steady�flow.�The�drill�cuttings�will�travel�around�the�cyclone�until�they�fall�

through�the�bottom�opening�into�a�sample�bag.�These�bags�are�marked�with�the�location�and�depth�

of�the�place�where�the�sample�was�collected�and�can�be�transported�directly�to�the�assay�lab�for�

analysis.�It�is�a�non-contaminated�system�and�complies�with�SAMREC�(South�African�Mineral�

Reporting�of�Exploration�Results)�Standards.�

����Exploration�Drilling�

EXPLORATION�DRILLING�is�used�in�the�mining�industry�to�probe�the�contents�of�known�Ore�Deposits�

at�potential�sites.�By�withdrawing�a�sample�of�rock�from�the�Orebody,�Geologists�then�analyse�the�

sample�by�chemical�assay�and�conduct�petrologic,�structural�and�mineralogical�studies�of�the�rock.�

����Bulk�Sampling�

The�taking�of�large�samples,�this�may�consist�of�large-diameter�drilling.�

The�taking�of�large�sampmples,�ththisis�m�mayay�c�cononsist�of�f�lalargrge-didiameter�drillllining.g.

SERVICES

15�

Page 2: SERVICES - TORQUE AFRICA · Air•Core•Drilling• • AIR•CORE•DRILLING•is•a•well-known•and•widely•used•method•when•it•comes•to•soft•rock•and•soil•

����Monitoring�Holes�

A�Borehole�at�a�selected�location�for�the�purpose�of�collecting�groundwater�data�(e.g.�water�levels,�

quality,�rainfall,�abstraction)�over�a�period�of�time�for�a�specific�groundwater�monitoring�objective.�

����Piling/�Construction�

Large�diameter�holes�are�drilled�then�filled�with�reinforcing�and�concrete.�

Typical�uses�are�in�the�building�industry�and�tower�foundations�for�anchors.�

����Percussion�Drilling�

PERCUSSION�ROTARY�AIR�BLAST�DRILLING�is�a�drilling�technique�that�makes�use�of��

Pneumatic�pressure�to�drive�the�steel�drill�bit�into�the�ground�in�order�to�create�a�hole.��

It�is�a�hammer�like�process�that�is�easily�able�to�penetrate�rock�in�order�to�find��

mineral�and�Ore�Deposits.�The�drill�bits�used�are�hollow.�The�debris�which��

results�from�the�drilling�process�shoots�out�of�the�earth�and�lands�next�to�the�machine,��

by�use�of�air�compression�

���Angled�Holes�

ANGLED�HOLES�are�drilled�at�a�pre�terminated�angle�into�the�Ore�Bodies�so�that�better�samples�of�

the�mineralization�can�be�taken.�Angled�holes�are�drilled�to�the�client�s�needs.�

Holeesss

����MMoonnniittoorriinngg�HHHoolleessMMM

16�

Page 3: SERVICES - TORQUE AFRICA · Air•Core•Drilling• • AIR•CORE•DRILLING•is•a•well-known•and•widely•used•method•when•it•comes•to•soft•rock•and•soil•

Air�Core�Drilling�

AIR�CORE�DRILLING�is�a�well-known�and�widely�used�method�when�it�comes�to�soft�rock�and�soil�

formations.�The�main�feature�of�this�drilling�method�is�that�it�makes�use�of�three�blades�that�cut�into�

the�earth.�The�blades�are�attached�to�a�hollow�tube.�

���ODEX�(Symmetric�Drilling)��

In�problem�formations�like�riverbed�and�highly�fractured�formations,�it�might�be�

necessary�to�install�the�casing�as�the�drilling�continues�as�the�formation�keeps�

collapsing�and�it�prevents�the�casing�to�be�inserted�normally.�Once�the�problem�area�is�

cased-off�and�the�solid�rock�formation�was�penetrated,�normal�percussion�drilling�

can�continue�to�the�required�depth.�The�hole�can�then�be�cleaned�and�developed�

for�pump�testing�and�pump�installation.�

���Drilling�for�Boreholes�/�Water�Wells�

A�BOREHOLE�is�a�vertically�narrow�shaft�bored�in�the�

ground.�A�borehole�may�be�constructed�for�many��

different�purposes�including�the�extraction�of�water.��

A�Borehole�used�as�water�well�is�completed�by��

installing�a�vertical�pipe�(Casing)�and�well�screen��

to�keep�the�borehole�from�caving.�The�hole�is��

normally�100mm-600mm�in�diameter�

17�

Page 4: SERVICES - TORQUE AFRICA · Air•Core•Drilling• • AIR•CORE•DRILLING•is•a•well-known•and•widely•used•method•when•it•comes•to•soft•rock•and•soil•

�Blasting�

BLASTING�holes�is�most�commonly�used�in�the��

Mining�Industry.�Holes�are�drilled�in�a��

pattern�formation�which�are�then�filled�with�explosives.��

��Air�Core�Flushing�

This�system�is�to�identify�ore�bodies�and�consists�of�drilling�with�a�Core�Barrel�that�is�flushed�with�

air�and�backwashed�with�fluids.�AIR�CORE�is�drilled�from�70mm���250mm�in�diameter.�

Normally�Coal�targets�are�explored�with�this�system.��

����Mud�Rotary�

In�sand�and�clay�formations,�the�MUD�ROTARY�method�is�used.�It�is�a�specialized�method�that��

allows�us�to�drill�through�the�sand�and�leaves�the�hole�open�for�casing�installation.�A�screen��

is�placed�opposite�the�targeted�horizon�to�allow�the�water�to�flow�into�the�hole.��

Between�the�screen�and�coarse�sand,�a�filter�pack�is�inserted�to�prevent�any�fine�material�

�flowing�back�into�the�hole.�

18�

Page 5: SERVICES - TORQUE AFRICA · Air•Core•Drilling• • AIR•CORE•DRILLING•is•a•well-known•and•widely•used•method•when•it•comes•to•soft•rock•and•soil•

Open�Pit�Grade�Control�

OPEN�PIT�GRADE�CONTROL�generally�entails�the�sampling�and�assaying�of�blast�hole�cuttings�

followed�by�the�estimation�of�Ore�control�block�model�grades.�The�estimated�block�grades�are�used�

in�turn�to�design�surface�polygons�or�dig�lines�that�outline�and�separate�various�Ore�types�and�waste�

material�or�the�purposes�of�mining.�In�an�Open�Pit�operation,�this�involves�the�sampling�of�blast�hole�

cuttings�produced�by�down-the-hole�hammer�drills�and�the�classification�of�bench�reserves�into�Ore,�

low�grade�or�waste�material,�or�into�various�metallurgical�types.�

����WASSARA�

The�WASSARA�Technology�uses�water�to�power�the�hammer.�This�makes�it�the�ideal��

choice�for�most�drilling�applications�in�ground�Engineering�-�for�drilling�in�sensitive��

areas�as�well�as�for�drilling�long�straight�holes.�The�water-powered�DTH�Hammer�is�capable�of��

penetrating�any�formation�while�maintaining�speed�and�straightness.��

WE�ARE�THE�DRILLING�MASTERS

19�