The Prieska Deposit is a VMS-style deposit, with mineralisation defined along 2.4km of a northwest-southeast trending strike extent and down to a depth of 1.25km. Mineralisation of Cu, Zn, silver (Ag) and gold (Au) is in massive sulphides distributed as a persistent lens within gneiss rock assemblages.

Satellite deposit potential has been demonstrated with recent intersections of sulphide mineralisation at Ayoba, 5km from the proposed Prieska ore processing plant. Further afield, available historical data and recent
exploration work by Orion has confirmed the existence of numerous follow-up massive sulphide Cu-Zn-rich targets within the nearby mineral tenements also held by Orion.

The mineralised zone outcrop has a strike of 2,400m, is oxidised and / or affected by leached and supergene enrichment to a depth of approximately 100m and crops out as a well- developed gossan. It has a dip of between 55° and 80° to the northeast at surface and a strike of 130° to the north. Current drilling indicates that the Deep Sulphides has a strike length of at least 2860m in depth.

The thickness of the mineralised zone exceeds 30m in places but averages between 7m and 9m. The mineralised zone persists to a depth of 1,100m (as deep as 1,228m in one section) after which it is upturned due to the folding.

Both open pit and underground mining are planned for the duration of the Foundation Phase. Underground mining is planned to commence on completion of mine dewatering, shaft refurbishment and underground infrastructure establishment, some 24 months from site mobilisation. Underground mining is then scheduled to build up over 14 months to a steady-state run-of-mine production rate of 200ktpm (kilo tonnes per month) or 2.4Mtpa (million tonnes per annum).

Tunnel development remaining from the previous mining operations allows for early access to underground production mining areas. A combination of Longhole Open Stoping with Fill (LHOSF) and Drift-and-Fill (D&F) mining methods will be used, supported with paste back-filling. Some low-profile, D&F mining is planned in the latter years, along with open-pit mining of the near-surface +105 Level Supergene Deposit in the back two years of the mining plan.

Some 20.8Mt of material at an average grade of 1.1% Cu and 3.4% Zn is planned to be mined and processed to produce 189kt of Cu and 580kt of Zn contained in differentiated concentrates during the Foundation Phase.

Ore processing is planned to involve conventional differential froth flotation to produce separate copper and zinc concentrates at average grades of 24% Cu and 50% Zn from underground mined material. Minor modifications to the processing plant will allow the open-pit material to be treated at the end of the mine life, on a campaign basis, to produce separate copper and zinc concentrates at average grades of 26% copper and 36% zinc.

The flowsheet for processing underground material is similar to the flowsheet used during previous mining operations. Life-of-mine metal recoveries into concentrates are anticipated to be 84.4% for Cu and 83.9% for Zn from treating underground mined material and 66.7% and 59.4% for Cu and Zn respectively for open-pit mined material.

The concentrates will be trucked to Groveput, 50km from site, and then railed to the Port of Ngqura (at Coega) for export to smelters in Asia and Europe. Net smelter returns for the Cu and Zn concentrates (accounting for metal payabilities, treatment and refining charges, and penalty provisions) are expected to be 98.7% and 71.3% of market metal prices for Cu and Zn respectively for underground sourced metal; and 91.2% and 53.7% for Cu and Zn respectively for open-pit sourced material.