Aurelia Metals’ Hera Copper-Gold Mine, NSWMine Development, Raise Boring, Shotcreting
Aurelia Metals’ Hera underground mine is a high grade gold and base metal project located in western New South Wales. The deposits represent typical “Cobar Style” ore systems, which have a strong historical precedent for large scale, high-grade, long life mining operations.
Like most underground mines in Australia, Hera is accessed by a single decline tunnel. The speed this decline progresses determines the critical path to mine production.
PYBAR is contracted for all primary underground construction works: life of mine development and production, incorporating installation of in cycle shotcrete and stope backfilling with both CAF (cemented aggregate fill) and mined waste; vertical development to establish return air rises and escape ways, and establishment of onsite batch plant for concrete and fibrecrete.
PYBAR provides all immediate supervision and operating labour, plant and materials, while Aurelia provides technical direction around such functions as geology, and engineering design and survey.
Since PYBAR commenced onsite in January 2013, PYBAR has been using a standard development mining fleet in an application requiring in-cycle fibrecrete and dual rock-bolt ground support to advance the 5m high, 5.5m wide, 1:7 decline.
Full scale development commenced in March 2013 and over the six month period to December 2013, the advance of the decline face averaged 6.3m per day (almost one vertical metre per day).
Since December 2013, the focus has extended to accessing and developing the orebody in preparation for stoping operations.
It was envisioned at the tendering stage that PYBAR would require a second development jumbo on site from March 2014, however, due to the team’s ‘over-performance’ with a single jumbo, the second jumbo was not required.
Using a standard fleet to achieve the rapid development rates that PYBAR has at Hera facilitates a number of advantages such as in-house equipment maintenance, capital cost reduction, flexibility and post-project disposal value.