Dateline Resources (ASX:DTR) said its bankable feasibility study (BFS) for its Colosseum gold and rare earth element project in California has returned a pre-tax net present value (NPV) of $785 million at a 5% discount rate and a pre-tax internal rate of return (IRR) of 49.5%, according to a Monday Australian bourse filing.

The company said undiscounted pre-tax free cash flow is $1.08 billion, rising to $1.36 billion at spot prices, with start-up capital of $249 million, including $16 million in capitalized mining costs, plus a $25 million contingency.

The project has a 10.4-year mine life producing 573,000 ounces of gold in total, with average annual gold production of 75,000 ounces over the first six years and peak gold sales of 102,000 ounces in year six, at an all-in sustaining cost (AISC) of $1,825 per ounce, the filing added.

The project has a low 3:1 strip ratio supporting lower operating costs, with 55,000 ounces of inferred mineral resources within the pit shell not included in the ore reserve, with the additional underground potential in the northeast of the North Pit open at depth and subject to ongoing drilling, the filing added.