OPERATIONS Australia Region
|ST IVES||AGNEW||GRANNY SMITH||GRUYERE|
|Mining method||Open pit and underground||Underground||Underground||Open pit|
|Operational infrastructure||St Ives has four underground mine areas and seven open pits contributing to the Mineral Reserve. There are seven underground mines and 16 open pits contributing to the Mineral Resource. Current ore stockpiles contribute 6.1% of the Mineral Reserve at the reporting date. There is a centralised administrative office and engineering workshop complex.||Agnew operates two underground mines, namely Waroonga and New Holland, now amalgamated into
the Agnew One Mine Complex. At Waroonga, ore is sourced from the Waroonga North, Kath, Fitzroy
Bengal Hastings (FBH), Main and Kim lodes, accessed via declines. New Holland mining occurs in four
primary areas: Sheba South, Sheba, Cinderella and Himitsu. These areas are accessed via declines.
There are also centralised administrative offices, engineering workshops at Waroonga and New
Holland, and one active CIP processing plant (1.3Mtpa capacity). The plant capacity will be increased to
1.35Mtpa by the end of 2022.
A hybrid renewable power plant was commissioned in 2019/2020 including solar, wind turbine, gas generator, battery power storage and diesel back-up power solutions.
|Granny Smith has one underground mine contributing to the Mineral Reserves and Mineral Resources. The Mineral Reserves do not include any open pits but one open pit contributes to the Mineral Resources. The mine has one ore stockpile in the LoM plan. Granny Smith has centralised administrative offices and engineering workshops.||The Gruyere JV Mineral Reserve comprises five open pits plus ore stockpiles. The Mineral Resource includes seven open pits and one underground deposit. The operation has a processing plant with TSF and is supported by a power station with gas pipeline and power distribution lines. Borefields and water supply infrastructure, centralised administrative offices, engineering workshops, accommodation village, airstrip and road networks are all developed. Construction of a 12MW solar farm commenced at the beginning of 2021 and will be completed by Q1 2022.|
|Mineral processing and TSFs||
||The Agnew processing plant consists of a tertiary crushing circuit, followed by a two-stage ball milling
circuit with gravity and a conventional leach/CIP gold recovery circuit (1.3Mtpa capacity). The plant
capacity will be increased to 1.35Mtpa by the end of 2022.
Agnew’s TSFs 1 and 2, and an adjoined above-ground paddock storage facility, are decommissioned. TSF 3 is an in-pit facility at the Redeemer pit, operational since it was commissioned in 2004. TSF 3 has been irregularly topped up since commissioning TSF 4. TSF 4 is an in-pit facility located at the Songvang pit and has a remaining LoM storage capacity of ~6.5Mt. All the Lawlers TSFs are closed and rehabilitated.
Ore is processed at the milling/leach/CIP processing plant under campaign milling conditions located 15km north-east of the Wallaby underground mine. Granny Smith operates a single TSF complex that comprises three compartments, known as cells 1, 2 and 3. A fourth cell (cell 4) will be constructed in early 2022 next to cell 3 to provide additional tailings capacity for the rest of the LoM.
Cell 1 has a High B ANCOLD consequence rating and was raised to its final permitted crest elevation of 448m relative level (mRL) in late 2016. It has a remaining LoM storage capacity of ~0.80Mt and is currently active.
Cell 2 was raised to its final permitted crest elevation of 448.5mRL in 2012. This cell has a High B ANCOLD consequence rating, is filled to capacity and is harvested for paste fill.
Cell 3 has a High B ANCOLD consequence rating and is currently being raised to an elevation of 434mRL (final permitted elevation of 437mRL). The cell 3F lift will be completed by March 2022 and will provide 1.97Mt capacity.
All ore mined is processed in the Gruyere plant, which consists of primary crushing, SAG/ball milling, gravity and carbon in leach (CIL) circuits. The processing plant was designed to 7.5Mtpa but subsequent work shows this can be increased to 9.262Mtpa for 2022 and then increased to 10Mtpa by 2024.
The TSF perimeter embankment is constructed in a downstream manner (in stages) to enclose a surface area of ~203ha at Stage 1 (starter) and 231ha at Stage 6 (final). The TSF has a High B ANCOLD consequence rating and a remaining LoM storage capacity of ~78Mt. Studies are in progress to extend the existing TSF to increase capacity by 29Mt – 34Mt
|Brief history and regional geology||Orogenic greenstone gold deposits (hydrothermal) are hosted in several different styles of lodes. Although all Agnew deposits broadly occur at the intersections between structures and stratigraphy, there are subtle differences in alteration and mineralisation that are controlled in part by the local host rock chemistry. Mineralisation zones are discontinuous with short range predictability.|
|Exploration||The Australian mines continued to see the real benefits of consistent annual investment in extensional and near-mine exploration (invested US$59.4m in 2021 and between US$48m and US$76m per year over the past six years).|
St Ives, Agnew, Granny Smith and Gruyere JV gold mines located in Western Australia
The Australia region operates a portfolio of predominantly low-cost, relatively long-life mines and has a strong pipeline of projects configured to drive reserve replacement and life extension.
The Australian mines continued to see the real benefits of consistent annual investment in extensional and near-mine exploration (invested US$59.4m in 2021 and between US$48m and US$76m per year over the past six years). Agnew and Granny Smith increased Mineral Resources and Mineral Reserves net of depletion, while St Ives provided an important offset to depletion despite a net Reserve reduction. The year-on-year growth in Mineral Reserves at Gruyere (28%), Agnew (11%) and Granny Smith (2%) means that the region is well positioned to deliver on near to medium-term growth options. The region again exceeded 1Moz gold production in 2021, repeating the achievement of 2020.
The Gruyere JV achieved strong year-on-year growth in Mineral Resources (10%) and Mineral Reserves (28%), net of depletion, following the completion of a pit expansion PFS, which allowed steepening of the pit walls and increased conversion of Resources to Reserves.
An exploration deep drilling programme beneath the Gruyere resource pit shell was completed during 2021 and suggests that the ore body extends below currently defined Resources but grades and tonnages are not yet defined beyond a mineral inventory level. While JV partner Gold Road Resources has declared an underground Resource as an alternative development scenario to extracting deeper Resources below the current open pit, Gold Fields does not consider that underground options potentially meet investment criteria at this stage.
Far Southeast – Philippines
The FSE project is located in the wellknown mining district of Mankayan in the Cordillera region of Northern Luzon, ~250km north of Manila.
The project is held by Far Southeast Gold Resources Inc. (FSGRI), a JV between Lepanto Consolidated Mining Company (LCMC) and Gold Fields. To date, Gold Fields has acquired 40% of FSGRI for US$230m, and has the option to acquire a further 20% for US$110m, incurring initial development costs totalling US$165m.
GREW BY 3% NET OF DEPLETION
GREW BY 5% NET OF DEPLETION
|*||Agnew, St Ives and Granny Smith, 100% attributable to Gold Fields, Gruyere JV 50% attributable to Gold Fields, FSE 40% attributable to Gold Fields|
|AUSTRALIA REGION MINERAL RESOURCES AND RESERVES 2021 – PDF 21MB|
Stuart J. Mathews
Executive Vice President:
Stuart Mathews is an international mining professional with 25 years' experience having worked in Australia (Queensland, NSW, WA), Mexico and New Zealand. He has progressed through geology ranks to Geology Manager level and in the last 12 years worked in project development and general operations management to COO level. Stuart joined Gold Fields in mid-2013 initially at St. Ives, as then General Manager at Granny Smith Mine after which he became Vice President Operations: Australia. From February 1, 2017 Stuart took over the position of Executive Vice President: Australasia.