Giga Metals (TSX: GIGA) announced that, based on ongoing metallurgical testwork, it has obtained significantly improved nickel and cobalt recoveries for samples from the Turnagain deposit in northern British Columbia.
Recent tests have shown that separating fast-floating nickel minerals from slower-floating material allows this latter portion to be treated with either a flotation cleaning circuit and/or a concentrate regrind, potentially improving metal recoveries by several percent over the prior conventional flowsheet. The conventional rougher-cleaner flowsheet entailed nickel recovery to a high-grade sulphide concentrate grading 15% to 20% nickel.
“The improvement in recoveries is significant enough that we have decided to suspend work on the preliminary economic assessment while confirmatory metallurgical test work, including locked-cycle tests, is completed,” Martin Vydra, the company’s president said in a release. “The new results will be included in the PEA, and completion is now expected late in the second quarter.”
A 2011 preliminary economic assessment for Turnagain outlined a staged 43,400 t/d to 84,600 t/d open pit operation producing an average of 36,558 tonnes of nickel and 2,063 tonnes of cobalt per year in concentrate over a 27-year life. In October, the company released metallurgical test work results: locked cycle tests delivered concentrate grades of 18% to 22% nickel with recoveries on the order of 50% to 60%.
(This article first appeared in the Canadian Mining Journal)