The predominant mega-structure of the mining area is the northwest-plunging Nkana syncline. This structure is asymmetric, with a curved axial plane inclined steeply to the northwest in the trough of the syncline but upright to westward dipping at higher structural levels. A complex occupies the axial zone of the syncline but this folding dies out on its flanks. As a result of the north-westerly plunge of the Nkana syncline, the present land surface represents a horizontal section through progressively higher structural levels of the syncline from southeast to northwest.

Within the Nkana mining area there are four underground mines and a series of open pits. The open pits are under care and maintenance and have therefore been excluded from Ore Reserves and included under Mineral Resources. All are situated on the north-eastern limb of the Nkana Syncline area. Other cupriferous zones are present in the nose and southwest limb of the syncline. The orebodies are stratiform and are mainly confined to a recognisable ore formation, which occurs near the base of the Katangan sequence within the Lower Roan Group of the Mine Series. In the underground workings, the principal copper ore minerals are chalcopyrite and bornite with subordinate chalcocite. There is a zoning in the geographical distribution of these minerals. Cobalt occurs as carrollite and cobaltiferious pyrite. The principal ore minerals are malachite, pseudomalchite, chrysocolla, native copper, cuprite and libethenite. In the open pit, malachite and chrysocolla are the principal ore minerals in the zone of oxidation closer to the surface. In some places however, vermiculite, malachite pseudomalachite and accessory wad are more important. At deeper levels chalcopyrite, bornite and chalcocite are predominantly present.

The rocks of the Mufulira Basin are asymmetrically folded, moderately dipping on the south western flank and sub vertical on the north eastern limb, outcropping at Mokambo on the DRC border. The Roan sediments in the Mufulira syncline in the vicinity of the mine dip at approximately 45º to the north east. Small folds and minor faults are present within the mine area. The Lower Roan arenaceous quartzites and greywackes are the host rocks to the copper mineralisation.

In the Mufulira mining area, the Basement Complex topography appears to have exerted a significant structural control during deformation. The distribution of ore minerals in all three orebodies is stratigraphically controlled, occurring dominantly as disseminations, blebs and irregular masses. The principal copper minerals are chalcopyrite (60%), bornite (40%), and minor/trace chalcocite. Oxide minerals are confined to near surface occurrences, and supergene enrichment zones. Generally the deposit is structurally simple being characterised by three main folds that are in part overturned with a plunge and dip approximately 10º to the northeast. The basin is open and untested at depth.

Nkana.
The Nkana Mine produces copper and cobalt ore from four sources: North Shaft, Mindola Sub Vertical, Central Shaft and South Ore Body (“SOB”). In addition, Nkana produces copper from open pits.

The underground mining operations are accessed by shafts namely Central, Mindola Sub-vertical (“SV”), SOB and Mindola North Shaft (“MNS”). Underground mining operations started in 1931 with the oldest operating shaft being Central Shaft. The mining methods used include Vertical Crater Retreat (“VCR”), Sub-Level Caving (“SLC”), and Longitudinal Room and Pillar (“RAP”). Average underground production for the last five years is 3.4 million tonnes per annum (“Mtpa”) of ore at 1.94 %Cu and 0.12 %Co.

Mufulira.
The mining methods employed at Mufulira Mine are variants of Mechanised Continuous Retreat (“MCR”). The variant mining methods are Mechanised Continuous Retreat 1 (“MCR1”) and Mechanised Continuous Retreat 2 (“MCR2”), employed at Mufulira West and Mufulira Central. RAP mining is employed at Mufulira East. Mining of the Mufulira ore bodies is divided into three areas:
* Mufulira East;
* Mufulira Central; and
* Mufulira West.
Mufulira Central is further sub divided into the Upper, Central and Deeps areas, based on elevation.

At Nkana Mopani operates a concentrator, Cobalt Plant and Leach plants. Conventional methods are employed in the concentrator namely; crushing, grinding, flotation and dewatering. Copper and cobalt concentrates are produced from a bulk concentrate by a segregation process. At Nkana, the concentrator operates in a conventional manner, and has a capacity of 12 000 mt per day. Primary stage crushing of ore is done underground while the secondary and tertiary stage crushing takes place at the concentrator. Ball mills grind the crushed ore for subsequent flotation to produce a copper concentrate grade of approximately 30%.

Nkana has a mine and processing plant and produces a sulphide rich concentrate which is transported to Mufulira for further treatment.

At Nkana the cobalt floats with the copper and then has to be separated out by a differential float using lime to alter the pH and sodium cyanide; this is not an exact process and as a result some of the copper remai ........