JOHANNESBURG - Australian mining company Orion Minerals said on Monday that it has successfully completed follow-up locked-cycle metallurgical test work on the deeper mineralised domains at its Prieska Zinc-Copper Project and confirmed excellent copper and zinc metal recoveries.
Last week, Orion Minerals completed the infill and extension drilling program at its Prieska Zinc-Copper Project located in the Areachap Belt in South Africa's Northern Cape province.
The Prieska Zinc-Copper 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.
Excellent recoveries of both copper and zinc into separate, high-quality concentrates have been achieved using the froth-flotation process that was used in historical operations.
In addition, the use of modern metallurgical reagents – which have advantages in terms of health and safety, environmental management as well as in potential capital and operating cost savings – is showing encouraging results.
Errol Smart, Orion's managing director, said the results from the locked-cycle test work programme confirmed that it can include and use the historical mine metallurgical performance in the ongoing Bankable Feasibility Study, allowing the miner to complete the design of the process plant.
"This is an important result, which shows that we can expect to at least match and potentially exceed the historical plant performance and concentrate qualities," Smart said.
"The additional test work findings also indicate that we can use modern reagents and exclude cyanide from the process, bringing both health and safety and environmental management benefits to the project while achieving likely capital and operating cost reductions."
The Prieska Project area encompasses the historical Prieska Copper Mine which was profitably operated by Anglovaal as an underground zinc and copper mine, exploiting the Copperton deposit between 1971 and 1991, processing on average three million tonnes per year to produce 1.01 million tonnes of zinc and 430,000 tonnes of copper in concentrates.
Orion is now investigating the establishment of new mining operations targeting the extraction of the remaining zinc-copper mineralisation at the Prieska volcanogenic massive sulphide deposit.
The company undertook two major phases of drilling at the Prieska Project targeting near surface mineralisation expected to be amenable to open pit mining and the deep sulphide target below the historical mine, which is expected to form the cornerstone of the company's development strategy.