Westgold Resources has announced that its Board has approved the expansion of the Big Bell Project in Cue, Western Australia, which will incorporate a new Long Hole Open Stoping (LHOS) operation below the existing sublevel cave.
Big Bell is located 25km west of Cue and 50km from Westgold’s Tuckabianna processing hub. Mining at Big Bell commenced in the early 1920’s as an underground mine.
The current open pit void was excavated between April 1989 and 1993, with a portal cut in late 1993 by previous operators to provide underground access. The modern underground mine commenced in 1994 and was closed in June 2003, with the sublevel caving (SLC) operations re-started by Westgold in mid-2016.
The Big Bell mine has produced approximately 3Moz of gold at greater than 4,000oz per vertical metre.
Westgold achieved steady state productivity rates from the SLC in the March 2022 quarter, with the Big Bell operations team repeatedly delivering quarterly production records throughout 2022-23 and 2023-22.
Westgold has said that the Big Bell mine cornerstones its Murchison operations, providing the bulk of the ore tonnage which feeds the Tuckabianna mill, with surplus feed being processed at the Bluebird mill. This ‘base load’ feed enables total mill utilisation across the Murchison region and allows for cost-efficient processing of higher-grade ores such as that from Blue Bird, Paddy’s Flat and Great Fingall.
The Big Bell LHOS will extend this base load feed to an initial 16 years by accessing the deeper extensions of the Big Bell orebody, without impeding productivity from the current SLC operation. Development of the deeper extensions will utilise the existing mining fleet and mine infrastructure, opening up a second production front and increasing the overall mined grade through more selective mining.
To establish this second production front, a LHOS operation with paste fill methodology will be employed below the current SLC footprint. This methodology will ensure greater grade selectivity is available to Westgold and optimises the management of the stress regime in the mine.
Westgold Managing Director, Wayne Bramwell, said that Big Bell now has a long and profitable life ahead of it.
“This expansion underwrites the future of our Murchison operations and provides Westgold with further optionality to leverage our existing processing capital,” Mr Bramwell said.
“The economics of making our biggest mine bigger is compelling. Big Bell will provide baseload feed for our Tuckabianna and Bluebird processing hubs across its planned 16-year mine life and its ore will be supplemented with high-grade, high margin ores from the Bluebird mine at Meekatharra, and the recently announced Great Fingall mine near Cue.
“There are very few mines in the Australian gold sector that can boast a 16-year mine life. Big Bell has delivered nearly three million ounces of gold production to date and with this expansion now approved, the mine is set to ring true to its name.”