The company said yesterday it had achieved full plant ramp up to design capacity, with 18 days at or higher than design throughput, with no significant issues.
It said minor commissioning issues had temporary impacts on the plant since start-up, including excessive vibration in the secondary crushing units, Intensive Leach Reactor (ILR) efficiencies and de-sliming, elution circuit efficiencies and temperature optimisation and deficiencies in process control logic programming and operating protocols.
Chairman and CEO Steven Dean said all essential modifications were completed, ore production remained on plan and below budget and 2018 guidance would be provided in January.
The operation poured its first gold in October.
Phase one is expected to produce 87,000 ounces of gold per year over 8.5 years at an all-in sustaining cost of C$690/oz (US$538/oz) and a phase two expansion is being investigated.
Atlantic had a working capital deficit around C$16.5 million (US$12.9 million) at the end of September but believed it had sufficient funding to meet its obligations for the next 12 months from existing treasury, as well as estimated future operating cash flows.
Its shares closed C1c lower to $1.50, capitalising it above $273 million.