PERTH (miningweekly.com) – Copper and gold miner Oz Minerals has further cemented its plans for the Carrapateena copper/gold project, in Western Australia, increasing the project’s current budget to A$90-million.

At the end of March, some A$53-million had already been spent, with a further A$37-million to be spent on continued decline construction, further mine design optimisation to bring it to feasibility study stage, and to accelerate all other non-mining work packages through an early contractor involvement (ECI) model.

Oz Minerals told shareholders on Friday that under the ECI model, appointed contractors would undertake design, engineering and construction of key aspects of the mine on an open book basis, prior to entering a fixed price contract, allowing the company to lock in pricing and potentially accelerate the commitment phase of the project schedule.

An updated prefeasibility study estimated that the Carrapateena project could deliver 61 000 t/y of copper and 63 000 oz/y of gold over an estimated 20-year mine life, with project costs estimated at A$980-million.

Meanwhile, Oz Minerals on Friday also published its March quarter production results and reported a fall in copper and gold output, owing to heavy rainfall impacting on operations.

Total copper production for the quarter under review reached 25 079 t, down from the 29 758 t produced in the previous quarter, while gold production was down from 32 205 oz to 26 135 oz over the same period.

The company noted that the Prominent Hill mine plan would see production ramp up in the second half of the year, benefiting from the completion of the second underground decline in the third quarter, which would provide additional haulage access and an associated uplift in production.

Total copper production guidance for the full year remains unchanged at between 105 000 t and 115 000 t, and gold production is forecast at between 115 000 oz and 125 000 oz.