Fortune Minerals is updating the 2014 feasibility study for its NICO cobalt-gold-bismuth-copper project 160 km northwest of Yellowknife. Hatch, P&E Mining Consultants and Micon International have been engaged to produce the new study.
Four scenarios are contemplated:
Produce cobalt and bismuth concentrates at the mine site and ship these to a proposed refinery in southern Canada (the original scenario). Gold dor?(C), cobalt sulphate, bismuth ingots and copper cement would be produced.Build only the mine and mill at the site to produce cobalt and bismuth concentrates. Gold would be recovered by cyanide leaching and refined into dor?(C). Cobalt and bismuth concentrates would be sold to third party processors.Gold dor?(C) and cobalt and bismuth concentrates would be produced at the mine site. A gold-bismuth concentrate would be sold to third party processors. Cobalt concentrate would be shipped to a lower capital cost refinery in southern Canada to make cobalt sulphate.Cobalt and bismuth concentrates from the mine site would be shipped to a refinery in southern Canada for processing into gold dor?(C), a cobalt carbonate intermediate product, bismuth ingots and copper cement.Meanwhile, Fortune has made a number of improvements to the cobalt process that could reduce the capital cost of the refinery by up to C$200 million. Some of those changes are increasing the autoclave temperature and pressure, recirculation of autoclave leach liquor, treating the autoclave discharge to remove manganese as well as iron and arsenic, a redesigned copper cement circuit, and production of cobalt sulphate as the end project instead of cobalt sulphate.
Changes to the bismuth process and other improvements are also on the table. Bismuth concentrate would be leached with ferric chloride as before, but the electro-winning circuit would be dropped from the plans. Instead a bismuth oxychloride would be precipitated and smelted to a purity of 99.995% ingots. Mining will be by open pit rather than underground. Any underground mining of the gold rich deeper ores would be practiced only if conditions warrant.
(This article first appeared in the Canadian Mining Journal)