PERTH (miningweekly.com) – Optimisation work at the Mardie salt and potash project, in Western Australia, has resulted in increased production and improved economics.

ASX-listed BCI Minerals on Wednesday said that expansion of the proposed evaporation area had resulted in a near 20% increase in both the anticipated salt production, from 4.4-million tonnes a year to 5.35-million tonnes a year, and the anticipated sulphate of potash (SoP) production, from 120 000 t/y to 140 000 t/y.

Capital cost estimates for the Mardie project have increased from A$807-million estimated in the 2020 definitive feasibility study, to A$913-million, while salt all-in sustaining costs (AISC) have increased slightly from A$20.3/t to A$21.5/t, and SOP AISC have increased from A$310/t to A$337/t.

BCI said on Wednesday that the updated market rates for labour and operating contracts have been partially offset by increased economies of scale, which resulted in unit operating cost increases of around 6% overall.

The project’s pre-tax net present value has also increased from A$1.19-billion to A$1.6-billion, while annual earnings before interest, taxes, depreciation and amortization have increased from A$197-million to A$260-million.

Annual revenue at steady-state production has increased from A$386-million to A$505-million.

The project’s operating life has been maintained at a minimum of 60 years.

“The positive optimisation outcomes further demonstrate potential for Mardie to become the first new large-scale expansion of salt production in Australia in over 20 years, the largest salt project in Australia, and third largest solar evaporation project in the world,” said BCI MD Alwyn Vorster.

“Mardie has a compelling value proposition with an attractive market opportunity, green credentials and no insurmountable obstacles to development.”

A final investment decision on Mardie is expected by mid-2021 and securing approvals and tenure required to start the main construction is expected by the fourth quarter of this year, BCI said. First salt sales are expected by the third quarter of 2024, while first SOP sales are expected by the fourth quarter of 2025.

The Northern Australia Infrastructure Facility has previously agreed to provide a A$450-million loan to BCI for the development of the Mardie project.