In kicking off antimony-gold concentrate production from its freshly refurbished Hillgrove mining operation in New South Wales, Larvotto Resources has officially joined the ranks of Australian producers.
The company says it has successfully commissioned the processing plant's flotation circuit and concentrate filter presses, allowing it to produce its first saleable product just a month after restarting operations. The milestone clears the way for Larvotto to begin delivering into binding offtake agreements it has already secured with commodity trading giants Wogen Resources for its antimony and Glencore International AG for its gold.
Over its planned initial eight-year mine life, Hillgrove is forecast to produce 4900 tonnes of antimony and 40,500 ounces of gold per annum.
The antimony concentrate, cleaned to a 60 per cent product specification, is covered by a binding seven-year offtake agreement with Wogen Resources. The deal gives Wogen exclusive global sales rights for all antimony produced from Hillgrove during the period. Larvotto says Wogen representatives travelled from the UK to witness the company's first concentrate production, a solid vote of confidence in the newly commissioned operation.
A separate binding agreement will see all gold concentrate produced during the first seven years of mining sold to Glencore, covering an expected annual offtake of about 15,000 dry metric tonnes of concentrate.
It's also worth noting that Larvotto is using a gravity gold separation circuit at the front end of the mill. However, rather than relying on classic low-gravity gold recovery devices like simple spiral arrays or jigs, the modernised Hillgrove flow sheet relies strictly on centrifugal and multi-gravity units to intercept the gold before it enters the flotation circuits.
The primary workhorse of the gravity circuit is a Knelson concentrator, which sits within the grinding and milling circuit. As the primary ball mill reduces the ore size down to the target micron-size range, the pulp passes through the centrifugal Knelson unit.
The company's employment of a gravity circuit means a portion of its estimated 40,500 ounces of gold per year will likely be recovered as doré bars directly on-site.
Larvotto Resources managing director Ron Heeks said: “With the successful production of first concentrate, we now move into the delivery phase of the offtake agreements we have secured, namely the antimony offtake with Wogen Resources and the gold concentrate offtake with Glencore. These partnerships are significant, providing Larvotto with established access to global commodity markets and supply chains.”
The Hillgrove project, 23 kilometres east of Armidale in northern NSW, already hosts a significant resource of 1.7 million ounces of gold equivalent at an impressive grade of 7.4 grams per tonne (g/t) gold equivalent, ranking it among the world’s top ten antimony deposits and the biggest in Australia.
Despite this red letter moment in Hillgrove's development, the company is not resting on its laurels. It has already defined a significant exploration target for the new Midas lode, along strike from existing workings near the plant site, with a preferred midpoint estimate of 3.95 million tonnes at 5.16 g/t gold equivalent, for 656,000 ounces of gold. The broader conceptual range reported for Midas spans from 2.7Mt to 10.7Mt, containing between 223,000 and 2.95 million ounces of gold equivalent.
Recent drilling at the Midas zone returned a spectacular hit of 8 metres at 16.11 g/t gold equivalent, the highest-grade gold-antimony intersection ever recorded for the zone. The standout result came from a diamond hole which bored through 8m assaying 16.11g/t gold equivalent from 301m, including 4.5m at 27.78g/t gold equivalent from 302.5m depth.
The company says that potential also exists for a third payable metal at Hillgrove, with drilling at the Blacklode prospect intercepting a remarkable 0.4m grading 9.09 per cent tungsten trioxide. Larvotto has already defined an initial tungsten mineral resource of 4,774 tonnes of tungsten trioxide.
Historically, tungsten mineralisation has never been estimated as part of the Hillgrove mineral resources. But once the company completes its studies on the scale and mineability potential of its tungsten resources, it could soon find itself producing a second critical industrial metal, alongside antimony.
The Hillgrove process plant already features an entirely independent, pre-existing tungsten gravity circuit. While it sits separately from the main gold-antimony recovery circuits, Larvotto aims to map out and re-integrate the tungsten infrastructure to exploit its tungsten stream as its antimony-gold production scales up.
Larvotto's restart of its Hillside operation seems impeccably timed. Antimony is a designated critical mineral in Australia, the US and Europe, and market watchers point to tightening geopolitical tensions and a push to secure supply chains outside of China. At the same time, gold has held above A$6000 per ounce this year, providing a strong tailwind for any new producer hitting the market.
Making the leap from explorer to producer is notoriously difficult; however, Larvotto appears to have navigated it with aplomb. With a fully funded operation, potentially three important commodities, and two product offtakes already locked in with global players, the company is now shifting its focus from building a mine to running one. And with a suite of surrounding nearby exploration targets screaming for the drill bit, that initial eight-year mine life might just be the start of the story.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Doug Bright
