Okorusu Fluorspar

Overview

Okorusu is one of the largest acid-grade fluorspar producers in the past peaking with an acidspar production of 132,000 t/a (97% CaF2).

Mining only followed the outcropping 4 major orebodies in open pits. Depth extension of all large orebodies with several tens’ meters of width and hundreds of meters length have been proven to continue at depth for several hundreds of meters. Furthermore, where drill records exist, the ore grade improves to depth. Therefore, Okorusu’s future lies in developing a long-term underground mine under the central A-D deposit. Initial mining concepts were developed for a highly efficient underground mine with a main access drive from plant area.

The company developed a new geological model which resulted in a mineral resource estimate of 18 Mt Resources at 41% CaF2. In addition, an exploration target of 20-40 Mt at 35-55% CaF2 was established for an initial underground mining operation. The mineralization extension to depth will be drill tested over the next months.

The mine uses a proven processing flowsheet with simple flotation and drying to produce acid- and metspar grade fluorspar. Magnetite is recovered as a byproduct. Tailings reprocessing is being tested, with the potential to recover fluorite and produce fertilizers from the contained apatite.

The actual fluorite mineralization as replacement bodies in carbonate rocks is of exceptional grade with 60-80% CaF2 but is locally diluted by crossing volcanic dykes and unmineralized carbonatite in the periphery. The company tests radiometric, color and XRT sorting to remove waste particles and upgrade feed to the flotation plant to >50% CaF2.

Okorusu is a fully licensed brownfields mine with a Mining License valid until December 2029 and a surrounding Exclusive Prospecting License covering the entire 8 km x 8 km mineralized intrusive system.