Newfield Resources has progressed with blasting to access an underground mine decline at its Tongo diamond mine, in Sierra Leone.
The company has excavated 42 600 m3 of material, with three blasts conducted so far and two blasts remaining, to bring the boxcut to the desired elevation for the portal access to be opened up.
Once blasting and excavation are completed, the boxcut side walls will be shaped. The 6 m by 4 m portal entrance will be opened up for the underground decline to be developed.
Director Karl Smithson said in a statement on Monday that the company wanted to access the high-grade Kundu and Lando kimberlites.
The Tongo mine hosts a 7.4-million-carat inferred and indicated diamond resource, of which 1.1-million carats have been classified as probable reserves. This delivers an eight-year life-of-mine, but Newfield believes that the mine life can be significantly increased through further resource-to-reserve conversion programmes.
As part of ongoing resource development work, Newfield has started further drilling and diamond assays on the Panguma kimberlite, which is located to the west of the Kundu and Lando kimberlites.