ASX- and Aim-listed Aura Energy’s recently completed front end engineering design (FEED) study for the Tiris uranium project, in Mauritania, has confirmed “excellent” economic returns, the company says.

The study also updated the technical and financial parameters of the 2023 enhanced feasibility study (EFS).

Aura says that, importantly, the FEED study has confirmed the adoption of a two-million-pound-a-year triuranium octoxide (U₃O₈) processing plant as the base case for the project development, confirming the globally significant scale of the operation.

The FEED study reinforces that the project is a near-term, low-cost and long-life mine, Aura says.

The exploration drilling programme that is currently under way to expand the mineral resources at Tiris East, is aimed at demonstrating the potential to extend the mine life beyond the initial 17 years, as well as the potential to expand production significantly above the current base case rate of two-million pounds a year of U₃O₈.

Key points from the FEED study include a net present value of $366-million, an internal rate of return of 34% post-tax and a 2.5-year payback, based on a uranium price of $80/lb U₃O₈.

It highlights an average base case production of 1.9-million pounds of U₃O₈ a year over a 17-year mine life.

According to the study, shallow free dig openpit mining and beneficiation would deliver a low-cost, high-grade leach feed averaging 1 997 parts per million (ppm) U₃O₈ for first five years and 1 743 ppm U₃O₈ over the life-of-mine.

The study outlines a low all-in sustaining cost of $34.5/lb U₃O₈, which Aura avers demonstrates strong margins.

The company also highlights an efficient capital cost of $230-million, supporting a long mine life.

A final investment decision is expected later this year.

If approved, construction is expected to take about 18 months.

“The FEED study clearly demonstrates that Tiris will be a low-cost, high-value, near-term uranium producer with the ability to scale in a very strong uranium market. The market is in structural deficit and likely to continue that way for an extended period.

The strong economics at Tiris are supported by the simple, low-risk mining and beneficiation that delivers the high-grade, 1 750 ppm to 2 000 ppm U₃O₈, ore to the leach plant and there are no requirements for crushing or grinding the ore. These high grades are only matched by the deep underground mines in Canada and exceeding any current or proposed openpit uranium mines worldwide,” says Aura MD and CEO Andrew Grove.

“The board believes the current exploration drilling is likely to deliver near-term resource growth around Tiris East. This will enhance the strong economics delivered in the FEED study, and also provide optionality to further expand the production rate beyond the current design of two-million pounds a year of U₃O₈ and extend the mine life.

“Mauritania is open for business, and we look forward to working with the government and all our stakeholders to develop the Tiris uranium project,” he adds.