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Exploration drilling advances.

Automation and versatility are primary requirements today

Exploration activity by international mining companies continues to grow. For the third year in a row, the amount spent in 1996 on the search for metals and minerals has increased - and the trend looks set to continue. Reviewing the budgets for companies with an annual expenditure of more than US$3 million, the Metals Economics Group identifies a cumulative anticipated expenditure of more than $3,500 million for last year, almost 30% higher than in 1995.

These figures hide another important trend. The median expenditure, according to MEG, was $7 million, with an arithmetic average of around $15.8 million. Whilst these particular figures were lower than for 1995 ($8.8 million and $17.5 million respectively), the actual number of companies spending more than the average jumped from 154 to 223. This 69% increase is attributed by MEG to "extraordinary" fund raising from junior exploration companies.

This growth in exploration expenditure translated into an active year for drill manufacturers, not least JKS Boyles which saw the commissioning of its newly-designed hydraulic drills, and existing models being operated in over 100 countries. Over the past two years, JKS Boyles has sold more drills from its manufacturing base in North Bay, certified as an ISO 9001 facility, than in any other two-year period since the industry-wide downturn a decade ago.

Destined for remote and often difficult drill sites around the globe, customers may require drills to include commissioning and operator training. They always include the company's guarantee of ongoing technical service and parts support.

Recently, new patents have been issued for design improvements to the company's TUFF line of down hole tools. TUFF rods have cut drilling costs significantly because they are lasting much longer than previous wireline rods.

JKS Boyles' most recent research and development success is with computer controlled underground coring drills. What began as a product development partnership with Falconbridge has since resulted in a line of automated drills currently operating at Canadian mines in Ontario, Quebec and British Columbia. The on-board computer simultaneously monitors and controls up to 22 drilling functions. This information is displayed for the driller on a full colour, touch-screen console. Other features include automatic feed control and, of course, unattended drilling.

The feedback from customers on the automated drills has been very positive, says president Bob Parsons. "Shortly after the first automated B-20 was commissioned at Falconbridge, they ordered a second unit. Other customers, including Heath and Sherwood Drilling, one of Canada's leading contractors, Westmin Resources Mining Group and Ontario Hydro, have all praised the contribution of automated drills to their bottom line."


The next phase for the automated drills will be the introduction of the Data Logging System. The DLS, which utilises a Windows based utility, stores and processes valuable drilling information so that shift reports and other data is generated automatically. It will even allow for remote trouble-shooting. From North Bay, JKS Boyles technicians will be able to conduct maintenance inspections on the B-20's functions while it continues to drill on a mine. The company is also working on a partnership agreement with Inco to computerise the nickel producer's diamond drilling fleet. This project gets underway early in 1997.

The Atlas Copco Craelius Diamec[R] 264 APC (Automatic Performance Control) rig is a programmable, microprocessor-controlled core drill for surface and underground exploration. The basis for optimum drilling economy is the ability to adapt drilling parameters to rock conditions. However, it is impossible for a driller to continuously adjust the feed force, revs/min and water flow as fast as the rock conditions change. Minor changes normally go unnoticed, whereas with major changes, the driller often reacts too slowly.

In order to achieve as near as possible optimum drilling economy, the 264 APC core drilling rig features its own computerised operator. Given some simple instructions, the APC function is able to control the entire drilling cycle, tailored to the particular rock conditions. The drill automatically and constantly senses and monitors the current hydraulic pressure and flows in the different circuits, and reacts to any changes within a fraction of a second.

APC offers higher, constant rates of penetration, much longer bit life and substantially less wear on rods and core barrels, and eliminates common drilling mistakes due to human error. While the APC is drilling, its human operator can carry out other duties.

The APC is able to optimise penetration rate second by second, shift by shift according to the actual drilling conditions. It acts instantly on any change in the rock formation that calls for adjustment in feed force, rotation speed or torque, or a complete shut-down. Before the operator has a chance to react to a problem, the APC has already taken action. However, the rig can still be operated manually, as the APC function can be disconnected if desired.

It can be equipped with three different feed lengths (850, 1,800 and 3,300 mm) and three rotation units to suit the most varied applications, either electrical or diesel power. It can be used with a wide range of drill rod sizes depending on the drilling depth.

In general, 1996 was a successful year for Hagby Asahi of Sweden (formerly Hagby). Most notably, perhaps, was the completion during the year of the final design of the company's automated computer controlled ONRAM 1000/4 CCD rig. The unit is currently being readied for field trials and it is anticipated that the rig will be introduced soon.

Further success for Hagby Asahi during 1996 was reported with the introduction of a thin wall wireline system for hard rock drilling in Scandinavia where up until only a few years ago, wireline was unheard of for hard rock applications. The Hagby Asahi system has three drilling dimensions - hole diameter 46 mm/core 29 mm; 56/39 mm and 76/57 mm. Combined with Hagby's long lasting, free cutting bits, the thin wall wireline system has added significantly to drilling performance.

With respect to drill bits, several modifications and improvements have been introduced to Hagby's series of ONRAM drills, the ONRAM 100, 300, 500 and 1000. These include the introduction of a new hydraulic motor on the ONRAM 100 rotation unit, the introduction of a new rod holder, mainly intended for underground work, fitting all the three larger units, and the introduction of a larger rotation unit for the ONRAM 1000 rig with the capacity to handle drilling diameters up to H wireline and T2 101 mm conventional drilling.

Small is beautiful

Building on the success of its Metre Eater pneumatic core drill, Boart Longyear Diamond Products has developed the Piranha, particularly designed for exploration drilling in confined underground spaces. At a total of 98 kg, the Piranha weighs less than half the Metre Eater. The Piranha can drill in a 1.2 m space with 600 mm AQ rods. Its rated capacity is 50 m horizontally and 30 m vertically. At the maximum 15 kW output, the air supply requirement is 600 kPa, falling to 500 kPa at 12 kW.

Piranha development testing started at the beginning of 1996, since when 10 units have been working in various applications in South Africa. The compact, modular design of the machine and its light weight mean that in most circumstances it can be mobilised to a drilling site, drill the required holes and move onto another site all in the same day; tasks that would take considerably more time to accomplish with larger units. It breaks down into three parts for easy transport underground.

The 15 kW air motor is silenced as standard and features easily replaceable vanes. The lightweight, easy to use rod puller offers fast rod handling and is simple to remove for rigging. The company also notes that the Piranha's self centring chuck jaws are easy and quick to replace at the working place. Finally, maintenance is facilitated by the reduced number of components for quick dismantling and assembly and reduced downtime.

Marlow Drilling's newest drill model, a derivate of the Mole DD3W multipurpose drill, incorporates an advanced modular design, which not only makes the unit extremely portable and versatile, it obviates the need for helicopter support- a significant cost saving over heavier conventional drill rigs.

Now rated to 300 m plus, the top head drive of the Mole DD3W provides two speed ranges - a high speed range of 0-1,600 rev/min for diamond core drilling, and a low speed range of 0-230 rev/min for hollow stem flight auger, rock/roller drag bit or down the he hole hammer drilling. A simple lever selects the required ratio in seconds. The drilled diameters range from 190 mm (continuous flight augers) down to 60 mm (for Thin Kerf BQ wireline).

The new drill is easily disassembled into nine modules (including the power and hydraulic modules) with a combined weigh of slightly more than 0.75 t, The mast module is the heaviest, weighing in at just 135 kg, with the remaining modules weighing under 100 kg each.

On surface, Tamrock Driltech's D40KX Exploration Drill is a high performance unit designed for drilling angled exploration holes using the centre sample recovery system (CSR), with either rotary or DTH drilling. The sub-frame mounted drill features a sliding mast, which can be positioned at any angle from vertical to 45 [degrees]. A hydraulic cylinder then slides the base of the mast downward, with 2.4 m of mast travel to contact the ground, providing a precise drilling angle. It is rated at 14,980 kg down pressure on the bit and 27,240 pullback.

A hydraulically-operated V-block assembly positions the drill pipe for ease of adding new lengths and a 1,524 mm adjustable jaw-type power tong is provided for breaking tight pipe joints.

A boom crane assembly with winch, for drill pipe loading rotates 359 [degrees], controlled by the drill helper at virtually any adjacent location by hand-held electric remote control. The system allows for simple addition and removal of pipe, the mast remains in either vertical or the angled drilling position. This loader system allows the use of various sizes and types of drill pipes.

Dando Drilling has added the Mintec 5 to its line of crawler-mounted rigs. The first has been purchased by an Indonesian coal producer to carry out in-pit drilling for production control, geotechnical investigation and also to operate as a blasthole rig as and where necessary. This is Dando's first rig in this class to be powered by a new pilot operated hydraulic system, similar to that found on the Dando 250.

The Mintec 5 has a pullback capacity of 5,000 kg and a rotary head torque of 2,980 Nm. An on-board compressor and foam injection pump were supplied to the Indonesian operator, along with a triple-tube, air flush coring system to allow fast coring to be carried out, essentially in this application for gaining advanced information for on-site blending of coal.

Pekka Mikkola, president of Suomen Malmi Oy (Smoy), of Finland, writing recently in sister publication geoDrilling International (February 1996, p.1) commenting on exploration drilling technology notes that it is: "at its best a well-integrated system in which the drill, the in-hole equipment, the ancillary equipment and the skills of the drill crew have been matched together. Thus, combining the best features of various diamond drilling techniques has appeared to be difficult in practice. However, in the future improved materials, improved production techniques and continuously growing international cooperation may create better opportunities to combine the strong points of wireline techniques, high-speed automatic drills and self-propelled multi-function drills."

Supplier Contacts

Atlas Copco Craelius, S-195 82 Marsta, Sweden. Tel: (+46 8) 591 78500. Fax: 591 18782.

Boart Longyear Diamond Products, PO Box 83586, South Hills 2136, South Africa. Tel: (+27 11) 907 2417. Fax 1092.

JKS Boyles, 640 McKeown Ave, PO Box 197, North Bay, Ontario, Canada P1B 8H2. Tel: (+1 705) 472 3320. Fax: 472 6843.

Dando Drilling International, Old Customs House, Wharf Rd, Littlehampton, West Sussex, BN17 5DN, UK. Tel: (+44 1903) 731312. Fax: 730305.

Hagby Asahi, Box 4, S-71321, Nora, Sweden. Tel: (+46 587) 14500. Fax 13380.

Marlow Drilling, Unit 1, Empstead Works, Henley-on-Thames RG9 2AE, UK. Tel: (+44 1491) 577 560. Fax 410 168.

Tamrock Driltech, PO Box 338, Driletech Drive, Alachua, FL 32615, US. Tel: (+1 904) 462 4100. Fax: 462 1015.
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Title Annotation:includes list of equipment suppliers
Publication:Mining Magazine
Date:Mar 1, 1997
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