Marantelli, who came onto the Metals X board in September, has more than 40 years' experience in the mining sector, including the past 18 years running openpit and underground mines in Australia, Turkey, Spain, Zambia, Canada and Mexico.

His job will be to get the Nifty underground mine to a run-rate of circa-40,000 tonnes per annum of copper.

Hallam, a metallurgist by profession, leaves after 14 years at Metals X, the past two years as MD following the demerger of the gold business into Westgold.

Metals X completed the acquisition of the Nifty operation (via a takeover of Aditya Birla), in mid-2016, and had aimed to reach the 40,000tpa copper rate in 2018.

However, it became apparent this year that the historical mainstay ‘chequerboard' mining area at the mine wouldn't allow that rate to be reached, meaning development had to be accelerated into new areas of the resource.

As well as Nifty, Metals X is also the 50% owner of the Renison tin operation in Tasmania, and the huge undeveloped Wingellina nickel-cobalt project in central Australia.

Metals X completed a A$50 million fundraising early in August by issuing new shares priced at 65c.

Shares in Metals X closed Monday down 5% at 44c, capitalising the company at $303 million.