The mineralized zones are at the western end of the Katangan copper belt.

These deposits are hosted mainly by metasedimentary rocks of the late Proterozoic Katangan system, a 7km thick succession of sediments with minor volcanics, volcanoclastics and intrusive rocks.

Primary mineralisation, in the form of sulphides, within the Lower Roan is associated with the Dolomies Stratified (DSTRAT) and Roches Siliceuses Feuilletées Foliated (Laminated) and Silicified Rocks (RFS) for the Ore-body Inferior (OBI) and the Schistes De Base or Basal Schists and Shales Dolomitiques Superieurs (SDB) or Upper Dolomitic Shales for the Ore-body Superior (OBS) and is thought to be syn-sedimentary in origin. Typical primary copper sulphide minerals are bornite, chalcopyrite, chalcocite and occasional native copper while cobalt is in the form of carrolite. The mineralization occurs as disseminations or in association with hydrothermal carbonate alteration and silicification.

These deposits are hosted mainly by metasedimentary rocks of the Late Proterozoic Katangan System, a 7km thick succession of sediments with minor volcanics, volcanoclastics and intrusives. Geochronological data indicate an age of deposition of the Katangan sediments of ~880 Ma and deformation during the Katangan Orogeny at <650 Ma. This deformation led to the formation of the northwest-southeast trending Lufilian Arc, which extends from Namibia on the west coast of Africa through to Zambia, lyin ........

The T17 OP had been mined to its ultimate final pit shell by 2013. Further pit optimizations indicated that the north-eastern portion of the pit could be extended but it would require a river diversion and additional measures to protect the GCM crusher adjacent to the final pit. A strategic decision was made in 2013 not to go ahead with the extension but to rather incorporate the remaining OP Mineral Reserve into the UG mine design, as shown in Figure 97, to avoid the risks associated with the OP extension. The pit was dewatered in 2013 after being dormant for two years, in preparation for the T17 pit-bottom portal, and 0.1 Mt of OP tonnes were mined to create the appropriate pit-bottom elevation in the vicinity of the portal.

The modifying factors that were used for the T17 UG design in the mining model for conversion to Mineral Reserves include:
- The stopes are designed at a cut-off of 1.2% TCu;
- Cut-off grade is calculated using an assumed long term price of $6,500 per tonne of copper and long term price of $60,000 per tonne of cobalt;
- An 8% combined geological loss and mining loss was applied to all longitudinal and transverse stopes;
- An allowance was made for 7.8% dilution on all longitudinal and transverse stopes at 0.5%TCu;
- The longitudinal stoping design consists of 48 m stopes with an 8 m wide pillar (12% rib pillar loss); and
- The transverse stoping design consists of 20 m stopes with an 8 m wide pillar (35% rib pill ........

The mixed ore milling consist of CM1 and BM1 (or CM2 and BM2), CM5, CM6 and BM6, CM7 and BM7 milling circuits.

The CM1/BM1 (or CM2/BM2) mills are operated in a closed circuit with a common cyclone clusters. CM5, CM6/BM6 and CM7/BM7 also have the same arrangement. All circuits will produce a grind of 80% -150 µm from a feed with an F80 of 150 mm. BM1/BM2, CM5, BM6 and BM7 operate with a ball load of up to 35%.

The feed to each mill circuit is measured and recorded using a weightometer installed on each AG or SAG mill feed conveyor. Process water, together with the crushed ore, is added to each AG or SAG mill to achieve a slurry solids content of 75% by mass within the mill. Scats conveyors are installed at the discharge of CM5, CM6 and CM7 to remove material from the milling area to a dedicated stockpile outside the building.

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