African mineral sands producer Base Resources is assessing the potential of mining only a subset of the North Dune and Bumamani deposits at its mineral sands operations in Kenya, after a prefeasibility study (PFS) concluded that it is not viable to mine the entirety of these deposits.
This is owing to a combination of low heavy mineral grade, high land acquisition costs and elevated slimes content and associated tailings disposal costs, the Australia-based miner said on Thursday.
The North Dune mineral resources are estimated at 194-million tonnes at 1.5% heavy mineral and 37% slimes, and the Bumamani mineral resources are estimated at 5.9-million tonnes at 1.9% heavy minerals and 21% slimes.
The Kwale North PFS found the higher slimes content of the North Dune, relative to the 26% average slimes content of the Kwale South Dune currently being mined, would require a significant investment in additional tailings handling infrastructure and development of a co-disposal methodology owing to the lack of suitable tailings storage facility sites, materially increasing capital and operating costs.
Regarding the assessment of a higher-grade option, Base said that it would leverage the work completed for the Kwale North PFS and that the study would be progressed on an accelerated timeline, with the results expected by mid-2021.