The historic Hillgrove gold-antimony mine, discovered in 1857, is about to be revived by Red River Resources (ASX: RVR) following the company boosting its gold resources.
Red River plans to begin gold production by the end of the year, with initial output based on the Bakers Creek stockpile, followed in late 2021 with a transition to underground mining.
The updated JORC compliant mineral resource now stands at 4.75 million tonnes at 4.4 grams per tonne gold and 1.6% antimony.
This equates to 668,000oz contained gold and 74,000t of antimony. The contained gold has been increased by 46% in the new resource figure.
In the priority Bakers Creek stockpile and Sunlight Lode, the resource has increased to 2.65Mt at 4.5g/t gold and 1.1% antimony.
The mine, located 23km east of Armidale in New South Wales, was placed on care and maintenance in 2014 due to low antimony prices.
Hillgrove was originally mined between 1857 and 1921, with the modern mining era beginning in 1969.
The mine has so far produced 730,000oz of gold, more than 50,000t of antimony and also tungsten as a by-product.
Hillgrove already seen $200m in investment over 16 years
Red River acquired Hillgrove last year from the previous operator.
The company estimates that more than $200 million has been spent since 2004, including the time it was operated by the former Straits Resources.
With the mine, Red River acquired a 250,000t per annum processing plant completed in 2009, offices, warehouses, assay laboratory and maintenance facilities along with mining and surface vehicles and tailings storage.
There is also about 10km of underground development.
Why Australian antimony miners struggled for years
Antimony is used as an alloy in lead batteries and in bullets. While as a compound, it acts as a flame retardant (including in children’s clothing) and is also used in pottery, paints and enamels.
The Hillgrove processing plant is capable of producing saleable gold and gold-antimony concentrates.
Chinese smelters kept the lid on non-Chinese antimony mining for many years by not paying for the gold contained within the antimony concentrate.
This was a killer for Anglo American when, in the 1970s, it operated the Blue Spec mine inland from Karratha in Western Australia (where the concentrate was almost equally divided between gold and antimony).
That company spent millions trying to separate the two — and then walked away.
But there was a game-changer in 2012. Those same smelters were struggling to get enough concentrate just as world antimony demand was forecast to rise markedly.
So, then the smelters were finally prepared to pay for the gold content.