PERTH (miningweekly.com) – An advanced prefeasibility study (PFS) into an openpit operation at the Santa Comba tungsten and tin project, in Spain, has shown that the project is economically robust and could complement the permitted underground mine.

ASX-listed Rafaella Resources noted that the openpit PFS estimated that the project would require a capital investment of A$53.2-million to construct a 1.3-million-tonne-a-year ore processing plant, a 1-million-tonne-a-year aggregates plant and associated mine infrastructure, to produce tungsten concentrate and aggregates.

The openpit operation is expected to deliver 7.4-million tonnes of tungsten ore over a mine life of seven years, and the openpit PFS estimated a pre-tax net present value of A$94.8-million and an internal rate of return of 32.6%, with a pay-back period of just over two years.

The PFS was based on a proven and probable ore reserve of 7.48-million tonnes at a grade of 0.15% tungsten, for 12.3-million tonnes of contained tungsten, with Rafaella noting that 90% of the openpit project area was yet to be drilled, while the wider project area also offered significant potential for expansion with a near-surface exploration target of between 25 000 t and 112 000 t of contained tungsten.

The openpit operation would also be complementary to the recommissioning of the high-grade underground operation, which has a Joint Ore Reserves Committee-compliant inferred resource of 2 752 t of contained tungsten and 662 000 t of contained tin, with an additional exploration target of between 6 000 t and 12 400 t of contained tungsten and between 1 300 t and 2 200 t of contained tin.

“The company is now able to move to the next important development stage and commence the openpit permit application process, presenting the project as one of strategic importance to Galicia and Spain,” said MD Steven Turner on Monday.

“The integrated Santa Comba project provides the company with a future world-class tungsten operation, combining a high-grade underground operation, which is highly synergistic to the recent San Finx tin and tungsten mine acquisition, with a large scale, high volume, openpit development. The project will bring major regional investment, securing long-term jobs and a responsibly operated domestic source of a critical metal, highly vulnerable to Chinese and Russian supply chain disruption.”