Polymetal International said it had given a green light to its Pox-2 gold project in Russia after completing a feasibility study.
Pre-production capital expenditure on the project were estimated at $431m and would be funded from the company's operating cash flows.
Detailed engineering and construction would start in the second quarter of 2019, with first production targeted in the third quarter of 2023.
The project's base case internal rate of return was 14% with a net present value of $112m.
The plant's design throughput capacity was 250-300 Ktpa of concentrate, depending on the levels of sulphur content.
'POX-2 leverages our core technical capabilities and creates substantial value,' chief executive Vitaly Nesis said.
'Emerging trends in the global gold mining industry make POX-2 a crucial element of the company's long-term strategy.'