ASX-listed gold producer, Horizon Minerals, continues to capitalise on a strong Australian-dollar gold price at its low-grade Boorara gold mine, 10km east of Kalgoorlie-Boulder, peeling off a rapid-fire $4.89 million in revenue. The bounty was secured courtesy of a second batch of contract trial mining and toll treatment of open-pit ore that culminated in the production of 1,845 ounces of gold that sold for an average $2,654 an ounce.
The Perth-based company had previously clocked up revenue of $2.93 million from the first Boorara contract mining and toll milling campaign that produced 1,050oz and realised a cracking sale price of $2,791 per ounce.
That opening gambit as part of the six-month production trial was generated from the processing of 26,340 tonnes of near-surface oxide ore at an average feed grade of 1.32 grams per tonne gold, with metallurgical recovery of 93.8 per cent.
Ore mined from Horizon’s three trial open pits – Regal East, Regal West and Crown Jewel – is being treated at Golden Mile Milling’s one million tonne per annum-capacity Lakewood mill, 7km west of Boorara, under the toll milling contract.
The second, recently completed milling campaign processed a total of 46,700 tonnes of ore from the Regal West and Regal East pits at an impressive overall gold recovery of 95.11 per cent
The reconciled grade for the upper oxide zones of Regal West of 1.21 g/t was slightly below expectations, but better grades at depth from Regal East helped shore up the latter’s reconciled grade to 1.40 g/t.
Horizon is looking to kick off the third toll milling campaign entailing the treatment of ore from the higher-grade Crown Jewel pit and the more consistent-grade deeper ore from the Regal West pit early next month.
All-in production costs of the trial Boorara gold production project were previously forecast at $1,682 an ounce, however, the company will undertake a full reconciliation of production and costs once the final milling campaign is finished in January 2021.
It says it will also conduct final mapping of the pits as well as a geological review and incorporate the data into an updated mineral resource estimate earmarked for completion in the March 2021 quarter.
Contract mining of the three trial pits carried out by Hampton Transport Services was all done and dusted last month. A total of 267,000 tonnes of ore – including high-grade and low-grade material – was extracted returning an average mine grade of 1.23 g/t, - about 25 per cent above the combined Boorara measured, indicated and inferred resource grade of 0.96 g/t from 16.45 million tonnes of ore for 507,000oz of contained gold.
Haulage of the remaining high-grade stockpiles – which have an estimated mine claim grade of 1.92 g/t – to the Lakewood plant, also taken care of by Hampton Transport, will continue until December 2021. In addition, Horizon plans to process a parcel of low-grade material for resource model and grade allocation testing purposes.
Horizon Minerals Managing Director, Jon Price said: “As we approach the halfway mark of toll milling, the results continue to demonstrate the tonnage and grade uplift potential when compared to the current global resource model and we look forward to the completion of milling and updating the resource model in the March quarter 2021.”
“This cash generating trial is an important step in the process of improving our understanding of this very large mineralised system at Boorara and de-risking the larger-scale development being assessed as part of the consolidated feasibility study.”
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By Matt Birney
