Rome Resources (RMR ) has released details of an updated mineral resource estimate for its Kalayi tin deposit at the Bisie North project in the Democratic Republic of Congo. 

The updated inferred estimate comprises 460,000 tonnes grading 1.47% tin, including 6,760 tonnes of tin at a 0.80% Sn cut-off grade. 

Compared with the maiden resource estimate published by Rome in October 2025 on the same cut-off basis, this represents a 45% increase in contained tin, a 32% increase in resource tonnage, and a 10% increase in average grade. 

Rome’s consultants MSA have also defined an area immediately southeast of the updated resource, lying along strike from the existing high-grade resource which, subject to further drilling, presents further potential for doubling the resource estimate. 

MSA's updated geological model now comprises 11 mineralised zones, up from seven in 2025, demonstrating the growing scale of the Kalayi deposit.

"I am delighted with Kalayi’s direction of travel,” said Paul Barrett, chief executive of Rome Resources.

“This is a genuinely high-grade tin deposit, and objectively, is getting better. The numbers that matter the most are not just the 45% increase in contained tin, it is also that both tonnage and grade have increased simultaneously, from 1.33% to 1.47% Sn. In the board’s view, resource growth without grade dilution is unusual and reflects improving geological confidence. At 2026 tin prices, we believe that the margin potential of a deposit at this grade, less than 10 km from established tin ore processing infrastructure, is compelling. Kalayi is only part of the Bisie North story. Mont Agoma is a separate and substantial polymetallic system with its own maiden resource of copper, tin and zinc. With copper prices at record highs, the polymetallic optionality Mont Agoma offers is increasingly significant and the undrilled southeast tin and northwest copper targets represents upside the current resource does not yet reflect.”

 

View from Vox

 

The picture emerging at Bisie North, across both Kalayi and Mont Agoma, is of a growing, multi-commodity critical minerals opportunity in the world's highest-grade tin district. It begins to look as though 20,000 tonnes of tin might be a realistic target for Bisie North, and with that in mind, it wouldn’t be too surprising if bigger players start to circle the asset. In the meantime, this is good progress.