Rio Tinto has completed the acquisition of Sumitomo Chemical Company's (SCC) 20.64% interest in New Zealand Aluminium Smelters (NZAS), making it the sole owner of the Tiwai Point aluminium smelter in New Zealand.

The transaction, first announced in May this year, has now been finalised, with Rio Tinto taking full ownership of the smelter.

In addition to the NZAS stake, Rio Tinto has also finalised the acquisition of SCC's 2.46% interest in Boyne Smelters (BSL).

Coupled with the recent purchase of Mitsubishi's 11.65% stake in BSL, Rio Tinto's share in BSL has increased to 73.5%.

The financial details of the acquisitions were not disclosed.

With NZAS now wholly under Rio Tinto's umbrella, the company is poised to optimise operations and leverage the full potential of the smelter.

Rio Tinto Aluminium Pacific Operations managing director Armando Torres said: “We are pleased the acquisition of SCC's stake in NZAS has now been finalised.

“This step, along with recently signed electricity arrangements to secure the future of the Tiwai Point smelter, reinforces our long-term commitment to New Zealand.”

Last month, Rio Tinto teamed up with Australian space exploration company Fleet Space Technologies to leverage advanced space technology and AI for lithium exploration at the Rincon Lithium Project in Argentina.

The collaboration aims to generate detailed 3D subsurface maps for a 100km² area, using Fleet Space's ExoSphere solution for real-time data collection and processing. Fuelled by Fleet Space’s satellite network, the ExoSphere system provides real-time data acquisition and processing through 3D Ambient Noise Tomography.