JOHANNESBURG (miningweekly.com) – Lithium developer Pilbara Minerals has seen a 136% increase in its total proved and probable ore reserve for its 100%-owned Pilgangoora lithium/tantalum project in Western Australia’s Pilbara region to 69.8-million tonnes, grading 1.26% lithium oxide (Li₂O).

This more-than-double upgrade was compared with the maiden ore reserve of 29.5-million tonnes, grading 1.3% Li₂O, used to underpin the March prefeasibility study, following an expanded resources programme.

The overall Pilgangoora ore reserve now comprises 883 000 t of contained Li₂O and 20.3-million pounds of contained tantalite.

“The significant increase in the ore reserve has meant that additional work was required to finalise site footprints including waste dumps, tailings management facility and surface water management designs. As a result, it is expected that the full details of the definitive feasibility study (DFS) results and financial model will be released in early September,” the company said in a statement on Monday.

The DFS is being undertaken on the basis of developing a standalone operation at Pilgangoora with a throughput rate of two-million tonnes a year. “However, the recent increases in both the global mineral resource and ore reserves will clearly support a future expansion of plant capacity. Studies are already under way to increase production capacity to four-million tons a year in the future, once operations at Pilgangoora have commenced at the initial targeted production rate,” the company added.

Pilbara Minerals MD Ken Brinsden said the increase reinforced Pilgangoora’s position as a globally significant hard rock lithium-tantalum deposit – highlighting the grade, quality and scalability of the deposit and setting the scene for the upcoming DFS, now in its final stages.

“Of particular note is the fact that the upgraded ore reserves have been calculated using a conservative assumed price for 6% battery grade spodumene concentrate of $460/t, which is well below the current market price and considerably below the medium-term prices being forecast by most major investment banks and commodity analysts.

“One of the key attributes of Pilgangoora is that, because of its exceptional grade, scale, low stripping ratio and great location it will be one of the lowest cost hard rock lithium operations in the world. That sets us apart from many of our peers and puts us in a position where we expect to have an extremely robust operation capable of generating strong margins at all stages of the lithium price cycle,” he highlighted.

Meanwhile, Pilbara appointed company secretary Alan Boys as alternate director, following current executive director Neil Biddle’s decision to step down, effective August 20.

Biddle will remain on the board as a nonexecutive director and will continue to provide significant strategic input and advice to the company. He also remains a significant shareholder.

Boys will stay in his position to the end of September, at a time when Biddle will be travelling extensively overseas.

The company has also appointed experienced commercial lawyer and corporate executive Alex Eastwood as general counsel, while assuming the role of company secretary from the end of August, replacing Boys who has held the position of company secretary since 2014.

Eastwood has more than 20 years’ experience as a commercial lawyer, company secretary and corporate finance executive.

Brinsden pointed out that the recent appointment of Brian Lynn as CFO and now the appointment of Eastwood reflected the growing depth of the company’s senior leadership team as it prepared to make the transition from explorer and developer to producer.