The plan outlines a development schedule for an openpit mine and processing facilities to extract and recover 120.5 million pounds of vanadium oxide over the project's expected seven-year mine life.

Prophecy said submission of the plan, incorporating new data from several consulting third parties, was the final step before publication of a notice of intent that triggered a year-long environmental impact statement process under the US Secretary of Interior's Order No 3355.

The Gibellini EIS will be one of the first under the order that mandates the final study cannot be more than 150 pages and must be completed within one year of publication of the notice of intent for the EIS in the federal register.

"With the filing of our plan of operations we expect the NOI will be published in Q1 of 2020. We are confident to meet the NOI schedule, just as we have done with the filing of the [plan]," said Prophecy CEO Mike Doolin.

Doolin said previously Gibellini was the only vanadium project positioned to start production in the US by 2022.

The project, in the Battle Mountain region of Nevada, is forecast to cost US$116.76 million to build, according to a June 2018 preliminary economic assessment. The PEA estimated an operating cost of $4.77/lb of vanadium, while the price of vanadium is currently trading at less than $10/lb in China, after hitting nearly $34/lb in November last year.