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, after which 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 supplementary modern reagents. 

The resultant rougher products are well suited to 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 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- (Jorc-) 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
Orion Minerals has raised an additional A$11-million through a share placement so that it can accelerate development on all fronts.

This equity capital raising funds the company beyond the Prieska zinc/copper project bankable feasibility study (BFS) and enables it to continue with regional exploration.

“Our view has always been that the base project, the Prieska project, is already great as a standalone project, but what sets Orion Minerals aside from its international peers is the regional exploration upside,” Orion CEO Errol Smart told Mining Weekly Online in an exclusive telephone interview.

The company, which began drilling deep holes a year ago, has completed 62 000 m of diamond drilling. It currently has 19 drilling rigs in action that produce more than 600 m of drill core a day.

“Now that we’ve drilled a much larger Joint Ore Reserves Committee (Jorc) resource than what we expected to do when we first set out, we’re also looking to doing an upscale on the production scope to get an optimised net present value of the project. Now that we’ve got 29.5 t of Jorc-compliant resource and it still remains open, we really have to look at an upscaled project, which is why we’re having to do this very intense drilling programme so that we have at least ten years’ worth of reserve in hand when we complete the bankable study,” he adds.

The target date for the BFS has been extended from October to the end of the year, hopefully before Christmas.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

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