Freetown: Stellar Diamonds said a preliminary economic assessment shows the Tongo kimberlite project in Sierra Leone can produce almost 1 million carats over the next 18 years, according to a company announcement.

“The objective was to define updated project economics for both surface and underground mining of the diamond resource in support of the mining license application,” according to the assessment by Paradigm Project Management.

The Tongo project has been assessed to have an 18 year mine life from both surface and underground mining, yielding a total of 955,930 carats. In the first four years, Stellar plans to produce 117,806 carats to provide early cash flow. The project will be built for around $24.2 million to establish the initial surface and underground mining operation.

“Early cash flow is expected to be generated from the initial surface mining but the mine also represents a long-term and sustainable operation which has the potential to generate solid cash flows from the sale of its very high quality, high grade diamonds over many years,” said Stellar Chief Executive Karl Smithson.