Channel sampling at Larvotto Resources’ Hillgrove gold-antimony project in New South Wales has delivered sparkling assays going as high as 63 grams per tonne gold, 13.82g/t silver and more than 30 per cent antimony.
Management says the impressive results highlight the high-grade nature of the operation, while samples from the 1.5-million-tonne historical tailings facility recorded gold grades exceeeding the average of many operating open pit mines.
The company recently kicked off metallurgical test work at Hillgrove after completing auger drilling at its tailings facility and collecting several tonnes of underground samples from the development-ready zones of the Metz mining area. Auger results showed consistent grades of more than 1.3g/t gold, with peak values from the tailings dam greater than 2g/t gold and 2 per cent antimony.
Additional underground results from 28 samples returned positive results including 22.5g/t gold, 14.63g/t and 11.89g/t from within three zones – the footwall, ore zone and hanging wall at the Metz mine, which has been highlighted by the company as its major focus for underground mining.
The Hillgrove project lies 23km east of Armidale in NSW and comprises four exploration leases and 48 granted mining leases across its 254 square kilometres of tenure. As the mine’s new operator, Larvotto says it aims to enhance recoveries by producing a higher-grade and cleaner concentrate product.
Management believes its latest testwork has the potential to generate a significantly more valuable product for sale. It has estimated the work is likely to take several months to complete.
Larvotto Resources managing director Ron Heeks said: “Previously, most of the processing focus was on antimony rather than gold, resulting in a considerable amount of gold deposited in the tailings dam. These samples will be subject to a detailed metallurgical study and TIMA mineralogy to determine the potential extraction rate in the case of the tails and optimal processing route for the underground mineralisation.”
The company acquired the 1.4-million-ounce gold equivalent operation after entering into a binding term sheet with the administrators of former owner Red River Resources for a purchase price of less than $6 per ounce.
With a grade of more than 6g/t gold equivalent – which can be broken down to 4.5g/t gold and 1.2 per cent antimony – the project cost Larvotto just $3 million, with about a further $5 million required to for the replacement of environmental bonds in compliance with NSW laws.
Significantly, the acquisition also includes an operational processing plant, which was put on care and maintenance in 2021. It features a 250,000 tonnes per annum capacity and came with associated infrastructure.
That makes it a serious financial bonus for the company as it would be looking at a bill likely to be north of $200 million to build the plant from scratch.
More than 204 individual mineral occurrences have been identified to date in the greater region, with the mineralisation developed as strike-extensive veins extending through 20km, with potentially depth-extensive, steeply-dipping fissures.
The area has been mined since the 1870s and the Hillgrove operations have produced more than 740,000 ounces of gold and about 40,000 tonnes of antimony. It is believed to be Australia’s biggest antimony deposit and also sits in the world’s top 10 resources for the silvery metalloid.
In addition, more than 2000 tonnes of scheelite concentrate, the principal ore mineral of tungsten, have been produced from the area.
During the production years at the operation from 1982, most processing focus was on antimony production rather than gold, which management says resulted in a considerable amount of gold being deposited in the tailings dam.
With the latest testing and sampling results set to be used to complete an upcoming preliminary feasibility study – not to mention recent record price highs for both gold and antimony – the market will be keeping a close eye on what Larvotto can deliver as it looks to bring Hillgrove back into production.
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By Michael Philipps
