The copper-cobalt minerals hosted in rocks of the Neoproterozoic Katangan Basin in the Central African copper belt metallogenic province of the DRC are a classic example of (low energy) sediment-hosted stratiform copper (SSC) ore system deposits. These deposits are economically significant, as they account for approximately 25% of the world’s copper production and known Mineral Reserves being second only to porphyry copper deposits in terms of copper production and the most important global cobalt resource.

The copper-cobalt deposits contained in a sedimentary series of rocks are known as the Mines Group in the Katanga sequence and the Roan Group in Zambia. The sediments are shallow-water shales, dolomitic shales, reefal dolomites and possible evaporitic lagoonal mudstones, formed on a platform marginal to a subsiding basin. The rocks are exposed in a series of tightly folded and thrusted anticlines and synclines, which generally trend east-west or southeast and are often overturned to the north. In spite of this deformation overprint, the mineralized zones, although sometimes lenticular along strike and down dip, as well as showing local diapiric forms, display remarkable large-scale continuity within the Mines Group.

The KOV OP deposit can be sub-divided into five main fragments within the KCC concession. These fragments can be classified as rafts of the Lower Roan lithologies which are separated by faults and/or RAT Lilas waste intrusions. The KOV fragments as follows:
KTE: Can be divided into three sub-fragments; KTEA forms a broad syncline dipping at approximately 40° north, KTEB lies below KTEA and dips approximately 30° north, whilst KTEC lies to the east of the KTEB and is sub-vertical.
Oliveira: A broad open syncline with the northern limb dipping 5° to the southwest and the southern limb dipping 25° to the northwest.
Virgule: A rectangular fragment which is faulted in the west, appearing as a ‘trouser leg” shape. It is dipping 20° to the southwest.
Variante: Forms a rough L-shape plane, with the eastern portion steeply dipping 70° to the north, shallow dipping 20° to the west.
FNSR: An over turned fragment, rectangular fragment which is dipping 25° to the southwest.

KOV OP comprises the five orebodies namely, Kamoto-East, Oliveira and Virgule (hence the name KOV), Variante and FNSR.

The sensitivity analyses of the factor of safety for different overall slope angles were carried out for the representative groundwater levels based on piezometer measurements in the area. The analyses were performed for the northern (N1, N2, N3 and N4), south eastern (SE) and southwestern (SW) slope regions. Based on the results of the stability analysis, overall slope angles of 28º - 35º are recommended for the final pit slopes.

These recommendations take into account the lack of structural data available outside the KOV OP ore zones where the majority of the final slopes are located.

KOV OP is an existing, large-scale operation. Mining related modifying factors applied to the KOV OP mine plan include a cut-off grade of 0.65% TCu and mining dilution of 20% and 5% overall losses. Ore production is primarily oxide and mixed material with only 8% sulphide ore.

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.

KCC is currently operating the WOL hydrometallurgical processing at their existing Luilu operation. The KCC WOL project is designed to process the mixed ore flotation tails from the KTC plant, as well as the roasted sulphide concentrate, to produce 300 ktpa of copper metal and 30 ktpa of cobalt contained in cobalt hydroxide. Further expansion is planned to achieve cobalt production capacity of 40 ktpa.

In the new KTC circuit the mixed ore from KOV OP and Mashamba East OP produce a sulphide prefloat concentrate, and oxide form tailings, which are pumped to Luilu for further processing. The sulphide ore from KTO continues to be treated in a separate sulphide mill and float circuit. The two sulphide concentrates are pumped to the roasters at Luilu for further processing.

Flotation
The flotation circuit consists of two distinct parallel flotation circuits followed by a common cleaner circuit. From the surge tank slurry is distributed to the two flotation circuit ........