Perth, Australia, June 15, 2011 - (ABN Newswire) - Focus Minerals (ASX:FML) is pleased to announce that it has commenced long-hole stoping
operations at The Mount project, which will play a key role in enabling the Company to hit its production target of 100,000 ounces in calendar 2011.
"Crater mining has not only improved productivity and enhanced safety, but also overcome various problems associated with conventional sublevel open stoping
previously employed at the mine (1)."
The scoping study considers the Golden Crown resource below the 550rl and the Great Fingall resource below the 800rl (tabulated below) and applies a longhole open stoping
in a top down sequence method.
methods use backfill as the permanent support medium, essentially to prevent the 'unravelling' of host rock which may affect adjacent stoping
"I am delighted to announce that stoping
has commenced at Prestea Underground," said Golden Star President and CEO Sam Coetzer.
The firing of the first stoping
ore represents a key milestone for the Company s underground mining operations and follows the production of the first copper concentrate from DeGrussa last week.
Blasthole (longhole) stoping
may be employed for ore widths as narrow as 3 m (10 feet).
The majority of the mineral reserves will be mined by longhole open stoping
plus 25% stope development) on 15-m sublevels and overhand cut and fill (15%).
To avoid the danger of falling rock, the Toro and all other mining equipment at Tara is operated by radio control when it is in the stoping
area, where the oversized material (typically in the 3-4 t block size) is broken into the as-blasted size required for hauling to the underground crushers.
Accordingly, the mining method has been adjusted to conventional mechanized cut-and-fill stoping
, stope lengths have been reduced to 40 m and ground control has improved, minimizing dilution.
The two longhole mining methods employed are transverse stoping
and longitudinal stoping
Golden Star plans to begin longitudinal stoping
of the B Shoot in the first quarter of 2017, with larger, transverse stopes expected to be accessed in the third quarter of the year.