Birimian Ltd. said July 4 that an updated pre-feasibility study for the Goulamina lithium project in southern Mali pegged a posttax net present value, discounted at 10%, of US$490 million, a 49.5% internal rate of return and a 2.6-year payback period.

In October 2017, a pre-feasibility study for Goulamina estimated a NPV, discounted at 10%, of between US$85.6 million and US$126.4 million and a 21% to 25% IRR.

The updated study incorporated an updated indicated and inferred resource of 103.2 million tonnes grading 1.34% lithium oxide for 1.39 million tonnes of contained lithium, as well as a maiden probable ore reserve of 31.2 million tonnes grading 1.56% lithium oxide for 486,000 tonnes of contained lithium oxide.

A lithium concentrate price of US$666 per tonne was used as basis in the study.

Total CapEx for the projected 16-year operation was pegged at US$199 million, which includes preproduction CapEx of US$147 million and a provision of US$33 million for contingency.

Annual concentrate production was pegged at 362,000 tonnes per annum of lithium grading 6% lithium oxide, using a 2-million-tonnes-per-annum processing plant, at an all-in sustaining cost of US$319 per tonne of lithium concentrate. C1 cash cost is pegged at US$281 per tonne.

The average EBITDA over the mine's life was estimated at US$128 million per year, with total posttax net cash flow for the operation pegged at US$1.32 billion.

The ASX-listed lithium explorer targets a final investment decision and the start of the construction in the first half of 2019, with plant commissioning scheduled for the first half of 2020.