Orion Gold NL
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Prieska Zinc-Copper Project (South Africa)

Advanced Zn-Cu project being fast tracked to feasibility


  • Major infrastructure in place (power, water, road/rail access, accommodation)
  • World class orebody, well understood
  • Recorded as one of world’s top 30 VMS deposits
  • Production of over 430,000 tonnes of copper and more than 1 million tonnes of zinc
  • Proven metallurgical process to produce premium product

The Prieka Project is located 270 kilometres south-west of Kimberley (the regional capital) in the Northern Cape province. Importantly, the project has access to significant local and regional infrastructure, with mine infrastructure including a regional power grid feed, bitumen access roads, access to a bulk, treated water supply and a 1,900 metre landing strip. Several large commercial wind and solar generation projects are operational in the surrounding area and the mine is located just 48 kilometres from a railway siding at Groveput with an open-access railway line connecting the site to the world-class export port of Saldanha Bay.

The current fous is on fast tracking the Prieska Project to production.  A Bankable Feasibility Study (BFS) was commenced in July 2017, with lead consultants appointed for these studies, along with the Environmental Impact Assessment (EIA) studies. The BFS and EIA work programs will be undertaken in parallel with the current activities (resource drilling, underground inspections and establishment of activities), taking advantage of the substantial historical database from mining and processing at the project.

Underground access has been re-established, allowing assessment of geotechnical conditions and the substantial remaining underground infrastructure.  Ground conditions and infrastructure in the underground mine to date have been found to generally be in a better state than was expected.  Orion is confident that mine refurbishment will not require substantial engineering effort. Power and vehicle access has now been gained to the +105 Level.

The Company is undertaking  two major phases of drilling at the Prieska Project targeting near surface mineralisation expected to be amenable to open pit mining (105 Level Target) and the Deep Sulphide Target below the historical mine, which is expected to form the cornerstone of the Company’s development strategy.

Prieska - South African mining success story

The Prieska Copper Mine operated from 1971 to 1991, employing approximately 4,000 people.  The mine milled 46.8mt, producing >430kt copper and >1mt zinc in concentrate.  Post May 1987, no more than 2mt of ore was blasted and milling of surface stockpiles was from 1989.  In 1991, the mine was closed and the site rehabilitated.

Historic resource estimation practices conformed to 'Industry best Practice' of the time, where mine surveys and geology plans show un-mined extensions and support the last reported mine planning reposts.

In 1987, a mine manager's proposal to then owners, Anoglvaal, showed:

    ** After this report, no more than 2mt of ore was blasted from underground (milling of surface stockpiles from 1989).  This is only for ore below 105m level.  This is an historical estimate & is not reported in accordance with the 2012 Edition of the JORC Code, nor is it certain whether Ore Reserves or Resources will be    defined until the Company's current exploration programs are completed.


Extensive historic drill hole data was also complied by the Company from records obtained, captured into digital models and plans.  This included:

Prieska - Extended history of metallurgical success

With Orion's progress and exploration programs currently underway, the Prieska Project is moving forward from its historical success.  Historical production demonstrated consistent concentrate grades and recoveries despite variable ore feed over the life of the mine.  Mill feed grade declined post 1987, reflecting the cessation of underground development.  Proven metallurgical process flowsheet at operation scale to handle variable ore feed. 


The BFS will optimise plant design and match proposed Orion mining sequence, being an initial open pit with a mixed oxide/transitional feed from the +105 Level Target transitioning to sulphide feed from underground operations.  The Company has sent 3.5t of samples for metallurgical test work to confirm previous results for the +105 level Target (open pit) material. 


For the latest information on our Prieska Project, please refer to our ASX Announcements page.