As the Osisko Group company progresses towards a Q3-scheduled pre-feasibility study, it has updated the market to say there are indications of a 50% increase compared to the PEA's mine/mill throughput—taking it from 4 million tonnes per year to 6 million tonnes per year.
The project is in the Malartic gold mining camp.
O3 flagged improved mine sequencing to limit peak mining rate increase to 15% with the increase of 50% in mill feed throughput and reduced peak stockpile of under 2 million tonnes compared to the 12 million tonnes at PEA.
The improvements made to productivity should see an increased truck size to 150 tonnes from 100 tonnes in the PEA and increased bench size from 5 metres to 10 metres, it said.
O3 said there has been a reduction of target grind size from 100 microns to 85 microns and an optimized leach-CIP circuit will be integrated in the mill design. This would result in 94.9% recoveries for Marban and 91.9% for Narlartic, it said.
The company said it has selected an improved conventional tailings scenario that combines a smaller management facility and in-pit deposition, enabling a smaller project footprint.
Canaccord Genuity Capital Markets analyst Michael Fairbairn said the increase in mill throughput is likely to have the greatest potential impact to mine economics.
"Beyond the throughput increase, we are cautiously optimistic on various components of the update, including the reduced tailings footprint and metallurgical results in line with our assumptions," he said.
The 2020 Marban PEA outlined a 11,000 tonnes per day open pit operation to produce an annual average of 115,000 ounces for 15.2 years, with the first 12 years at more than 130,000oz/y, from measured and indicated mineral resources of 54.2 million tonnes grading 1.10 grams per tonne, containing some 2.3 million oz.
"O3 Mining aims to become a leading gold producer and put the Marban project into production by 2026," the company says.
Shares in O3 were trading at C$2.08 (US$1.66) on June 7, valuing the company at C$142.45 million.
