Iron Creek cobalt mine is a high-grade cobalt project being explored and developed by First Cobalt, in the Lemhi County of central Idaho, approximately 42km south-west of Salmon, US.
First Cobalt, a vertically integrated North American cobalt exploration and development company, acquired US Cobalt (formerly Scientific Metals) in June 2018, to become the owner of Iron Creek cobalt mine.
The company announced a $9m work programme involving 70 drill holes totalling 30,000m depth, for the Iron Creek project, in the same month.
The first mineral resource estimate for the project is expected in October 2018, while the second resource estimate is expected in 2019.
The Iron Creek cobalt project is strategically significant for the US, as the Democratic Republic of Congo (DRC) currently accounts for approximately two-thirds of the world’s cobalt mining, while China almost monopolises cobalt processing by producing roughly 80% of the world’s total battery-grade cobalt.
The demand for battery-grade cobalt is on the rise due to increasing popularity of electric vehicles.
Iron Creek cobalt mine geology and mineralisation
The Iron Creek cobalt project comprises 90 lode mining claims covering 1,797 acres in the Blackbird copper-cobalt district, within the 65km-long Idaho Cobalt Belt.
Idaho Cobalt Belt represents the most abundant trend of cobalt mineralisation in the US. It was estimated to contain 16.8 million tonnes (Mt) of ore grading 0.74% cobalt, 1.37% copper and 1.04g/t gold, according to the U.S. Geological Survey, 2017.
The main historical mineralised zone on the property is called the No Name Zone, which is known to extend 1,066m in length and 244m in depth, with the width varying between 9m and 30m.
The recently identified mineralised zone on the property is the Waite Zone, which lies parallel and south to No Name Zone and is known to extend 520m in length and 250m in depth, with the width varying between 10m and 30m.
Mineralisation also occurs between the No Name and Waite Zones. The current drilling programme targets new mineralised zones in the footwall.
Iron Creek ore bodies feature semi-massive sulphide mineralisation hosted within argillaceous sedimentary rocks. Cobalt is predominantly found in fine grained massive pyrite at the Iron Creek mine.
Iron Creek drilling and development details
Historic drilling on the Iron Creek property traces back to the 1940s and was mostly concentrated on the No Name Zone. The inferred resource estimates for the property undertaken by companies including Hanna Mining, Noranda, Inspiration Mines and Cominco, in the 1980s and 1990s, considered the No Name Zone alone.
The historical exploratory work on the property included 30,000ft of diamond drilling and the mining of 1,500ft of underground workings.
The most credible historical inferred resource estimate for the Iron Creek cobalt mine was completed by Noranda in 1980, which estimated 1.3Mt of inferred ore resources grading 0.59% cobalt and 0.3% copper.
Scientific Metals acquired the Iron Creek property in July 2016 and further acquired the southern extension to the project in February 2017. Scientific Metals changed its name to US Cobalt in May 2017.
US Cobalt completed 40-hole 10,700m drilling programme covering 460m strike length in 2017 to confirm the historic resource estimate. The result of the 2017 drill programme is being used for inferred resource estimate on the property, which is expected by the end of 2018.
The 30,000m drilling programme initiated by First Cobalt in June 2018 aims at extending the strike length of the mineralised zone to 1,032m and to explore mineralisation beneath known ore bodies more than 300m below surface.
The 2018 drilling programme already confirmed the extension of the Waite Zone to the west for a total strike length of 520m, in July 2018.
The result of the 2018 drill programme is expected to bring a portion of Iron Creek’s inferred mineral resource into measured and indicated category by 2019.
Infrastructure facilities for Iron Creek cobalt mine
Iron Creek mine will utilise the existing 600m of underground development from three adits. The mine site is accessed via a 37km all weather road connecting to highway 93.
The Iron Creek ore will be processed at First Cobalt’s fully-permitted hydrometallurgical cobalt-silver-nickel refinery located in Cobalt, Ontario.
Commissioned in 1996, the 40 tonnes per day (tpd) refinery, built on a 40-acre site (expandable to 120 acres), houses three circuits including the pressure oxidation circuit, a solvent extraction circuit and a Merrill Crowe circuit.
The processing facility has been on care and maintenance since 2015.
Expansion and recommissioning study for the refinery is currently in progress.