ASX-listed gold producer, Wiluna Mining, has increased the total mineral resource inventory for the main Wiluna Mining Centre, or “WMC” at its historic Wiluna project in WA’s Yilgarn Craton by 9 per cent to a whopping 5.1 million ounces of gold. The updated indicated and inferred resource at the WMC of 52.98 million tonnes of ore going 3 grams per tonne for 5.1Moz of contained gold – at a 1 g/t cut-off grade – does not include about half a million ounces in the outlying Matilda and Lake Way deposits.
The global resource for the Wiluna district, including the WMC, Lake Way, Matilda, Galaxy mining centres, along with various stockpiles and tailings, varies depending on the cut-off grade used however the company says it could be as high as 143 million tonnes at 1.6 g/t gold. This eye-catching figure delivers a total gold content of 7.3 million ounces and positions Wiluna as Australia’s seventh largest gold district behind a list of revered names that include the Cadia mine in New South Wales and Kalgoorlie’s legendary Golden Mile.
The upgraded resource follows an exhaustive, methodical consolidation and standardising of recent and historical near-mine exploration data into a consistent format that Wiluna says underpins the company’s staged sulphide development plan.
In addition, the inclusion of results from the more than 45,000m of recently completed RC and diamond drilling into the dataset helps increase Wiluna’s geological confidence in the WMC sulphide resource and buttress the ore reserves estimation process.
The Perth-based company is planning a staged production expansion designed to initially produce about 120,000oz per annum of gold in concentrates from the underground mining of about 750,000 tonnes of sulphide ore a year, starting in September next year.
Wiluna, which is already producing about 60,000ozpa from remnant free milling ore generating about $3 million to $4 million a month of operating cash flow to help fund the stage one transition to sulphide production, hopes to more than double gold production from sulphide ore to about 250,000ozpa by late 2023/early 2024 supported by a long mine life.
A further mineral resource estimate update for the historic Wiluna project in the north-eastern Goldfields and interim ore reserves statement supporting the stage one sulphide expansion are expected to be released early in 2021.
Wiluna Mining Chairman, Milan Jerkovic said: “Our 2020 Wiluna mineral resource update is a summary of an extensive technical overhaul of the historical mineral resources and the inclusion of drilling we have done as part of our staged sulphide development strategy.”
“Our outstanding results from drilling … have greatly assisted us in reaching a new mineral resource that gives us far greater confidence in what we really have at Wiluna. The consistency of the results supports our belief that we can deliver into our sulphide strategy.”
“The Wiluna Mining Centre, which will be the focus on our staged sulphide development, is rated the 11th largest gold deposit (in Australia) on its own, with an almost identical size and grade as Jundee. We believe we can eventually end up as one of the largest gold deposits in Australia and become a Tier 1 gold mine in a Tier 1 jurisdiction.”
The company will ultimately pump an estimated $70 million into the CAPEX for the stage one transition to sulphides production, comprising about $25 million for a new concentrator – to complement Wiluna’s existing crushing and milling plant – and approximately $45 million for mine development, other capital works and reserve drilling.
Importantly, the WMC high-grade underground mineral resource estimate stands at 23.9Mt going an impressive 4.89 g/t for 3.76Moz of contained gold using a cut-off grade of 2.5 g/t gold, which Wiluna points out is relevant to the sulphide development plan as it relates to the underground sulphide mineral resource.
Punters reacted indifferently to Wiluna’s resource update, dragging its shares down 11 per cent during trading today when the broader Australian bourse was pummelled.
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By Matt Birney
