The company released a prefeasibility study for the project in northern Ontario, showing lower resource grades and a reduced net present value, while dropping a plan to build a refinery.
This month, Perpetua’s modified mine plan was identified as the preferred alternative due to improvements in water quality and temperature and site access benefits.
Highlighted results, all from the Upper Horizon area of the Hilltop target, include 60.2 g/t gold, 908.7 g/t silver, 15.7% lead and 1.1% zinc over 10 metres.