Rio Tinto Mining and Exploration has increased its stake in Sovereign Metals to 19.76% by exercising all of its share options for an investment of A$18.48m ($12.4m).

This move involved the acquisition of 34,549,598 new fully paid ordinary shares at A$0.535 apiece.

The funds will be channelled towards advancing the Kasiya Rutile-Graphite Project in Malawi.

Sovereign plans to utilise the proceeds to progress the current optimisation study of Kasiya, aiming to establish a “world-class” mining operation that can supply critical minerals to key industries including titanium pigment, titanium metal and lithium-ion batteries.

Kasiya is notable for its substantial deposits, with its mineral resource estimate showing 1.8 billion tonnes at 1% rutile and 1.4% graphite. This translates to 17.9 million tonnes (mt) of contained natural rutile and 24.4mt of contained graphite.

Rio Tinto's involvement extends beyond financial investment, as the company continues to provide Sovereign with technical and marketing support for the Kasiya project.

The company secured the option to acquire additional shares in Sovereign within 12 months of its initial subscription in July 2023.  

Rio Tinto’s initial investment of A$40.4m for 83,095,592 shares at A$0.486 each offered the miner a nearly 15% interest in Sovereign at that time.

The partnership also led to the formation of a joint technical committee between Sovereign and Rio Tinto to further the development of the Kasiya project.

Sovereign chairman Ben Stoikovich expressed confidence in the partnership, stating: “Rio Tinto’s further investment in Sovereign reaffirms Kasiya’s position as one of the most significant critical minerals projects globally.

“With Rio Tinto’s wealth of experience as one of the world’s largest and most accomplished global mining companies, Kasiya is well-positioned to potentially become a market leader in low-CO₂-footprint natural rutile and graphite.”