Copper QueryCaribou has been investigating the copper / gold circuit for more than a dozen years but to no avail. My understanding is that the ore is not amenable to an efficent copper extraction and, even if it did exist, there might be some zinc concentrate sacrified in the copper extraction process.
It is a good question for management to answer though (Yan Bourassa is the Vice President, Exploration & Mineral Resources).
Please note that Trevali issued its "2020 Mineral Reserves and Resources" on March 31, 2021 with no mention of gold or copper at all (and no updated information on the Ruttan mine in Manitoba since 2008).