PERTH (miningweekly.com) – Dual-listed copper developer Orion Minerals has flagged a possible A$15-million in cost savings at its Prieska copper/zinc project, in South Africa, after identifying two new 3 600 kW mills that can be incorporated at the project.
The new mills are immediately available at a significant discount to similar mills, which would only be available from manufacturers on long order, the ASX- and JSE-listed company said on Tuesday.
The company has moved to secure specific mills required to release improvements identified in value engineering studies on the ore processing plant design and layouts.
“We are very pleased that we can now begin to lock in the anticipated project optimisations with associated positive capital and operating capital cost savings. The plant optimisation studies progressed alongside studies on improved water treatment and optimisation of our mine-to-market schedule, all of which are now nearing completion,” said Orion MD and CEO Errol Smart.
“The successful metallurgical optimisation of the process flowsheet has culminated in securing the right to purchase two new mills which are available at a significant discount to mills which would otherwise have to be laced on order as long-lead items. These optimisations all promise to deliver an uplift in the already excellent investment case for the Prieska project.”
Smart said that securing the new mills facilitated the incorporation of a semi-autogenous grinding (SAG) mill into the ore processing flowsheet, in place of the ball milling arrangement selected in the bankable feasibility study, allowing significant operational flexibility and facilitating the processing of Prieska ore at a rate of up to 20% above design throughput, allowing capacity for future expansion.
The use of the SAG mill also simplifies the plant layout and operations, reducing the upfront capital expenditure (capex) and the estimated operating costs, while removing the requirement for multi-stage crushing and screening of rock ahead of milling.
Overall, capex for the plant has now been reduced by some A$15-million from the A$109-million originally estimated, while unit operating costs have been reduced by 5% from the base estimate of A$16.10/t.