NEW BRUNSWICK – Following modifications last December, Trevali Mining Corp.’s Caribou zinc-lead mill is experiencing higher throughputs and better zinc recovery. The Vancouver-based owner says the milling rate was 2,670 t/d in January and 2,707 t/d during the first three weeks of February.
Recoveries of all metals in concentrates were improved. Zinc recovery rose to 73% in February from 61% in Q3 2015. Lead recovery rose to 60% from 41%. Recovery of silver in the lead concentrate increased to 43% from 21%.
Final zinc concentrate grades were 47.7% Zn and 126 g/t Ag. The lead concentrate graded 41.0% Pb and 23.5 oz/t 805 g/t Ag.
Changes to the mill included a slightly finer primary grind size, to 30 microns from 35 microns. Ongoing improvements are also underway in other mill circuits.
Trevali (www.Trevali.com) says it has produced a preliminary economic assessment for the Caribou project based on measured, indicated and inferred resources, not reserves. A mine life of 6.3 years is planned.