The mine, located in south west Spain, now holds a JORC compliant inferred reserve of 47mln tonnes and almost 40,000 tonnes of contained tungsten metal at a 0.09% grade.
Golder Associates, which carried out the survey, also identified higher grade zones in the middle of, and adjacent to, the existing historic pit, which will be a focus for exploration going forward, the company said. There was a 0.04% cut-off grade.
Chairman Michael Masterman described the upgrade “an exceptional result” for the firm adding there significant potential to add “large JORC classified mineral resources and importantly higher grade at surface zones for initial mining.”
He said: “The report and 3D models give W the capacity to focus on the high grade areas at the surface of the current pit and adjacent to the existing mining pit, which show potential for early surface mine development.”
Additional drilling will be completed later this year on these targets and the northern extension, he added.
A preliminary geological model had been built for the extension exploration area based on the early 2013 extension drilling campaign results.
The extension exploration target is large (13-18 million tonnes) at a grade of 0.06% to 0.08%3 but there is currently insufficient information to classify this area as a mineral resource.
Further targeted drilling to delineate a JORC compliant mineral resource will be completed later in 2013, after production at the tailings project has commenced.
Development of La Parrilla tailings is advancing on schedule, W Resources added.
All of the key contracts, including civil works, have been signed; key long lead equipment has been ordered, and on site construction is set to commence in July 2013.
Shares rose 10% to 1.66p.