Reserves included in resources are 10.4 million probable tonnes grading 2% copper, 3.2% zinc, 0.37 g/t gold, and 34.6 g/t silver. Contained metal is 463 million lb. of copper, 734 million lb. of zinc, 120,000 oz. of gold and 11.6 million oz. of silver.
A prefeasibility study was prepared for the Kutcho project in 2017, but the new FS envisions a significantly changed project. Chief among these is the switch to open pit mining for most of the Main deposit. That allowed the resource estimate to be expanded and the project scale improved. The crusher feed rate has been increased to 4,500 t/day from 2,500 t/d earlier.
Ore sorting will be used, based on positive bulk sample test results. This should result in higher grade feed and a reduced flotation plant size, thereby reducing both capital and operating costs. Recent tests have also shown improved metallurgical recoveries (96.4% copper, 82.9% silver and 70.4% gold) compared to prior studies. Over the life of the mine, it will produce a 26% copper concentrate (9.4% zinc) and a 56.6% zinc concentrate (1.2% copper).
The Kutcho project has also been enhanced to reduce the environmental effects of development and mining. The more compact project footprint will avoid disturbing sensitive fish habitat. The open pit design and scheduling focus on minimizing the potential for acid rock drainage. Backfilling the pit and underground workings will reduce the area needed for tailings management as will the introduction of ore sorting.
“Given the significant scope of the design improvements between the 2017 PFS and the FS, we now anticipate the results of the feasibility study to be announced by the end of October 2021,” said Vince Sorace, president and CEO of Kutcho Copper. “Negotiations for our recently announced economic participation agreements with the Kaska Nation and the Tahltan Nation will be based on the optimized project design. Together, all these factors will allow us to continue advancing the project towards permitting and a production decision.”
The Kutcho project consists of one mining lease and 46 exploration claims covering an area of about 170.6 sq. km. It is accessible by air or a seasonal road from Dease Lake.
(This article first appeared in the Canadian Mining Journal)