A Step back in time to Hand-Held Mining for Profitability

2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Mike Turner, Peter Teasdale, Tim Green,
Abstract The Otter-Juan mine was closed by WMC-KNO in 1999 due to the combined effects of low Nickel prices and high mining costs. GBF Mining Pty Ltd purchased Otter-Juan Mine from WMC in early 2001 as part of WMC’s disinvestment from the nickel mines in the Kambalda area. Goldfield Mine Management (GMM), (a wholly owned subsidiary of GBF Pty Ltd) re-opened Otter –Juan in May 2001.

The Otter-Juan mine is one of the oldest mines in the Kambalda region and is now mining at depths below 1160mbs. Stresses are very high, rock mass deformation considerable, and the mine has a history of serious seismic activity. Orebody widths in the current mining area range from 2 to 2.5m, with dips ranging from 25 to 40°.

On taking over the operation, GMM converted the mining method from the previous mechanised drift and fill method to a slot-rise and strip method using hand held airlegs. During the latter years of production under the control of WMC production averaged around 12000 tonnes per month, with grades of 2.7% and orebody extraction of only 55 to 60%.

In the last three years of operation under the control of GMM the mine has produced an average of 12000 tonnes per month of ore at an average grade of 4.2% and with an orebody extraction of 70 to 75%. The mine is now highly profitable with at least another 3 years of reserves remaining at depth. The main benefits of the current method include reduced dilution and increased extraction. In the relatively poor ground conditions experienced this has only been possible using airleg mining, with excavations designed to suit conditions, support to suit rockmass deformations, and with improved extraction sequencing.

Other benefits have included improved conditions, reduced falls of ground incidents, and a dramatic reduction in seismic activity. These achievements have only been possible by stepping back in time and using traditional airleg stoping methods to extract the maximum amount of the orebody with minimum dilution.

This paper includes details of the mine history, geology, mining method, seismicity, and support.
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Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
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Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
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Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Year: 2004
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Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Year: 2004
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Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Daniel Robitaille, Steve Simard
Year: 2004
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Summary: The integration of pre-concentration technology into the underground narrow-vein mining scenario has the potential to change the entire economics of utilizing bulk mining methods in these situations. An idealized underground mining and processing system is presented, comprising elements of bulk mining, underground pre-concentration and backfill. Though a systems engineering approach, the implications of enabling the utilization of bulk mining methods in a narrow-vein deposit through the...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Bern Klein, Andrew Bamber
Year: 2004
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Summary: The application of underground pre-concentration technology (sorting) to narrow vein mining has the potential to change the entire economics of bulk mining methods when used in narrow vein situations. The rejection of waste at or near the face means that a higher-grade ore can be sent to surface. The waste rock can be reused directly as backfill. Swelling of the muck through blasting means that only about 60 to 65% can be used as fill. Planning and scheduling of the fill usage is key to the...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Malcolm Scoble, Andrew Bamber
Year: 2004
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Summary: Today still, the use of chemical explosives is the only effective way of breaking hard rock. Hydro Québec and Natural Resources Canada have joined their expertise in the development of thermal rock fragmentation to selective narrow-vein ore extraction using an electrical powered plasma arc torch to break the rock.

So far, laboratory tests have been conducted on granite blocks. The results obtained were sufficient to convince each partner to move a step further and realised a technico-econ...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Jean-Marie Fecteau, Marcel Laflamme, Gill Champoux
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Summary: The Doyon Mine’s Zone 1 (Altered Zone), found along the southern boundary of the mine, encompasses approximately 20% of the mining reserves. The mineralisation is found in a series of steeply dipping narrow veins, which are contained in an extremely weak host rock: a sericitic schist with RQD values ranging from 0 to 20. Longhole mining methods are used, with either longitudinal or transverse approaches, depending on the width of the ore zone.

Dilution is of critical importance in the...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Luc-Bernard Denoncourt
Year: 2004
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Summary: Long-term mine scheduling is one of the most difficult optimization problems. The problem is said to be NP-complete in that the best possible solution cannot be found any quicker than checking all possible permutations and combinations.

In current mining operations, it is important to report changes in long term plans as soon and as accurately as possible. Where geological data can change rapidly, such as in narrow vein deposits, the need to quickly identify and optimize different long term...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): David Muldowney, Paul Dunn
Year: 2004
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Summary: The future is here – or at least that’s what Mine Planners predicted some 15 years ago – that by 2004 we would have man-less mines running themselves using space-aged technology. Truthfully, though, there hasn’t been much change in mining methods in the past decade, but thankfully that’s all about to change.

The benefits of autonomous – even Tele-operated mining (especially in narrow-vein ore bodies) are well-known: increased production hours by eliminating travel time to and from the...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Walter Siggelkow
Year: 2004
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Summary: The Otter-Juan mine was closed by WMC-KNO in 1999 due to the combined effects of low Nickel prices and high mining costs. GBF Mining Pty Ltd purchased Otter-Juan Mine from WMC in early 2001 as part of WMC’s disinvestment from the nickel mines in the Kambalda area. Goldfield Mine Management (GMM), (a wholly owned subsidiary of GBF Pty Ltd) re-opened Otter –Juan in May 2001.

The Otter-Juan mine is one of the oldest mines in the Kambalda region and is now mining at depths below 1160mbs. ...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Author(s): Mike Turner, Peter Teasdale, Tim Green
Year: 2004
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Summary: Historical case studies will be reviewed which demonstrate how conventional analog geotechnical instrumentation has improved both the safety aspects and overall efficiency of Narrow Vein mining projects. However, the limitations of the analog technology deployed in these projects - which include (i) high purchase prices (ii) suspect reliability, (iii) complex interpretation procedures, and (iii) high priced data management tools – will be exposed.

Today, significantly more cost-effective...
Proceedings: 2nd Int'l Symposium on Mining Techniques of Narrow-Vein Deposits
Year: 2004
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