Name of the Project
Prieska zinc/copper project.

Location
The project is located 270 km south-west of Kimberley, in the Northern Cape, South Africa.

Client
Orion Minerals.

Project Description
The Prieska zinc/copper deposit has been recorded as one of the world’s top 30 volcanogenic massive sulphide deposits.

The mine was operated from 1971 to 1991, when it was closed and the site rehabilitated.

Initial metallurgical testwork at the proposed project has yielded positive results, demonstrating Prieska’s potential to produce high-quality marketable zinc and copper concentrates.

The results confirm that the remaining Prieska mineralisation, intersected to date, also responds well to metal concentration using froth flotation and recoveries, which might match or exceed historical performance.

Optimised rougher flotation conditions to produce differentiated copper and zinc concentrates from the deep sulphide target have also been determined, as have preliminary rougher conditions to produce a bulk copper and zinc concentrate from the shallow 105 Level target (openpit). Historical rougher flotation conditions have been improved through varying reagent dosages and using supplementary modern reagents. The resultant rougher products are well suited for upgrading in cleaner circuits to produce saleable products. Cleaner flotation testwork is continuing. Orion MD and CEO Errol Smart has indicated that the project will likely comprise an openpit and an underground operation, with the openpit to produce ore while the underground operations are dewatered and re-established.

The baseline project that Orion is evaluating envisages the mine producing about 100 000 t/m. This rate would translate into 12 000 t/y to 15 000 t/y of copper concentrate and 20 000 t/y to 25 000 t/y of zinc concentrate – consistent with the mine’s historical output.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
None stated.

Value
Not stated.

Duration
The project could start production by 2020. The project timeline envisages the completion of a Joint Ore Reserves Committee-compliant resource estimate by the first quarter of 2018, the lodging of a mining right application in the second quarter, feasibility study results by the fourth quarter and the start of construction of the plant in mid-2019. The proposed underground operation will likely start production by 2022.

Latest Developments
The maiden mineral resource for the Prieska project has exceeded expectations.

The company has announced a maiden mineral resource of 24.2-million tonnes, containing 873 655 t of zinc and 297 129 t of copper.

CEO Errol Smart has said in a statement that the project has demonstrated the value of modern exploration techniques and methodology applied to high-quality, underexplored deposits.

“As we intensify our regional exploration, having recently completed a regional airborne electromagnetic survey, we are confident of success in making further major discoveries in the Areachap belt,” he has said.

Orion has completed about 42 000 m of drilling on the deep sulphide target and has succeeded in validating extensive historical data for inclusion in geological modelling and geostatistical estimation.
Orion expects that the additional holes will provide satisfactory drill spacing to delineate mineral resource estimates with an increased level of confidence as early as next quarter.

This will allow for the inclusion of these mineral resources in detailed scheduling and mine design work as possible sources of feedstock for early production, potentially allowing for the delineation of a maiden ore reserve.

The openpit target resource presents an interesting early production opportunity for consideration in the bankable feasibility study (BFS). Orion has indicated that early mining of an openpit could bring forward (accelerate?) production, while mine dewatering is under way.

With engineering studies and metallurgical optimisation progressing well, Orion has said that it is very confident of a positive outcome for the BFS that is under way.

Further drilling will be conducted during the first half of 2018 to upgrade the confidence classification of a substantial portion of the global mineral resource.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Orion Minerals, +61 3 8080 7170, fax +61 3 8080 7174 or email info@orionminerals.com.au.