The company has the option to earn 100% of the project, which it says hosts the largest, highest grade primary vanadium deposit in North America and now exceeds the numbers quoted in a 2017 USGS paper.

Carlin's indicated resource stands at 24.64 million tonnes at 0.615% V2O5 for 303 million pounds, and inferred at 7.19Mt at 0.52% V2O5 for 75Mlb.

"Approximately 77% of the estimation reports to the indicated category, grades are higher than expected in the indicated category, and the contained pounds of V2O5 metal in the deposit in both indicated and inferred categories are higher than expected," president and CEO Paul Cowley said.

Both the inferred and indicated categories used a 0.3% cut-off grade and the results replace an historic 2010 resource estimate.

First Vanadium's estimate, prepared by SRK Consulting, used a value of US$12.50/lb V2O5.

The V2O5 price is back to a similar level to 12 months ago, of about $17/lb, having jumped to around $35/lb last year on growth in China's steel industry, a cutback in the country's production due to environmental regulations and the development of the energy storage market.

A series of shortlived price spikes over 40 years underline the volatility in the small vanadium market, the 2019 Vancouver Resource Investment Conference was told last month.

First Vanadium, previously Cornerstone Metals, was trading about C27c a year ago and rose to $1.96 in October as the V2O5 price spiked.

Its shares closed almost 14% higher yesterday at 66c, capitalising it at $25.7 million.