Granny Smith Mine (GSM) is an underground gold mining operation located 740km northeast of Perth, Western Australia. Our people fly to site on a chartered jet departing Perth Airport’s Terminal 2 four days a week to Laverton with a travel time of around 85 minutes, or via road for employees residing in host community towns including Laverton and Kalgoorlie.
Wallaby is the operation’s active mine, with mining administration and maintenance located nearby. Ore is processed at the Granny Smith Carbon-in-pulp (CIP) processing plant under campaign milling conditions and is located 12km east of the Wallaby underground mine.
Most GSM roles are rostered on an 8 days on, 6 days off roster or an 8 days on, 6 days off, 7 nights on, 7 days off roster.
Village rooms are all fully-contained ensuite, with Foxtel, 4G WIFI and Telstra phone coverage available. There are well-equipped recreational facilities, including a swimming pool, gym, two squash courts, two multi-use sports courts (tennis, basketball, indoor soccer/cricket), golf practice driving nets, pool and table-tennis tables and lawned gazebo area for special functions.
An active Social Committee organises a variety of events throughout the year, including family visits over Christmas.
The Gold Lounge is a dedicated area for relaxation and socialising, where residents can watch a movie or catch up with others in a quiet and comfortable setting.
A soundproof music room is available for camp residents to enjoy their instrument solo or get together with others to enjoy a jam session. Bring your own instruments or use Gold Fields’ provided equipment.
The site Health and Wellness Officer coordinates group activities and classes including CrossFit, yoga, boxing, mixed netball and soccer.
The recently refurbished tavern is located adjacent to the camp’s dining facilities and provides ATM facilities. The nearby village convenience store stocks an array of items including the newspaper Monday – Thursday and offers a barista coffee service.
The Goanna and Granny Smith deposits were discovered in 1979 by CSR Ltd. In 1988, Placer Pacific acquired CSR’s 60% interest, with the remaining 40% held by Delta Gold NL.
In 1989, mining commenced in the Granny Smith pit and continued in subsequent years with the development of the Goanna and Windich pits and nearby satellite ore bodies. First gold was poured in 1990.
The Wallaby deposit was discovered in 1998, 12km west of the Granny Smith pit, with first open pit ore delivered to the mill in November 2001. The Wallaby open-pit was mined from October 2001 until December 2006 and produced 1.5 million ounces of gold.
Underground mining at Wallaby commenced in December 2005 and is ongoing, with a mine life expectancy of ten years.
Gold Fields acquired 100% of the Granny Smith Gold Mine on 1 October 2013 as part of the purchase of the Yilgarn South operations.
The Wallaby underground operations involves mining across multiple ore lenses – Zone 60, Zone 70, Zone 80, Zone 90, Zone 100, Zone 110 and Zone 120.
Access to the Wallaby underground mine is via a portal established within the completed Wallaby open-pit. The mine operation is trackless, with underground truck haulage via the pit ramp to the surface.
Two primary underground mining methods are used, with minor adjustments to suit localised geometry; Inclined room and pillar (IRP) is used in areas with a moderate dip (10° to 35°) and moderate width zones (four to six metres), and transverse long-hole Stoping (TLHS) is used in zones which are thicker (six metres to 15m) with variable dips. Two other mining methods are used to a lesser extent: Narrow vein long-hole stoping may be applied in some areas with the benefit of reduced planned footwall dilution, and bulk long-hole stoping is used in thicker zones (15m plus) under varying dip conditions. In Zone 110 and Z120 paste fill is used to confine extracted stope hanging walls.
The annual production of the Wallaby mine is in-excess of 250,000 ounces per year.
The Granny Smith process plant has a capacity of 3.0 million tonnes per annum. The plant was originally commissioned in 1990 to treat oxide gold ores mined from the Goanna, Granny Smith, and Windich pits. The plant has been periodically upgraded, with the last expansion completed in 2015 to include a Gravity Circuit specifically designed to treat ore from the Wallaby underground deposit.
The plant consists of a two-stage crushing circuit, a standard SAG and Ball mill (SABC) grinding circuit, a gravity circuit, a Leach/Carbon in Pulp (CIP) train, a pressure Zadra elution circuit, a tailings recovery (TR) circuit and a thickened tailings storage facility (TSF). Currently, the overall metallurgical recovery averages around 92.6%.
Underscored by a common goal of creating shared benefits to those associated with our efforts, it means our people, the ecosystems in which we operate, and the rapport we have with our local and indigenous communities, is of the highest respect.