PERTH (miningweekly.com) – Metals miner Sandfire Resources was expecting a stronger second half of the 2015 financial year, following the installation of key process plant enhancements at its DeGrussa concentrator, in Western Australia.

Copper production during the three months to December reached 15 350 t, which was down from the 16 064 t achieved in the September quarter, while gold production reached 9 058 oz, compared with the 9 678 oz produced in the previous quarter.

Operations at the DeGrussa mine were impacted by a temporary suspension of mining activities in November last year, as a result of increased water flows into the Conductor 4/5 decline. As a precautionary measure, mining activities in the Conductor 1 and DeGrussa orebodies were suspended for a period of 28 days while dewatering and remedial activities were completed, during which time the DeGrussa concentrator continue to process run-of-mine stockpiles.

Sandfire noted that as a result of the temporary suspension of underground mining, mill throughput for the quarter was below the yearly rate of 1.5-million tonnes for the December quarter.

Two planned shutdowns of the processing plant were also undertaken during the quarter, to enable tie-ins and other project work associated with the processing enhancement projects.

The A$13-million plant enhancement was expected to further improve plant efficiency and increase copper recoveries to the targeted level of more than 90% during the second half of 2015.

For the second half of 2015, Sandfire expected DeGrussa to deliver between 33 000 t and 36 000 t of copper, with C1 cash operating costs expected to reach between $1.05/lb and $1.15/lb.

Meanwhile, Sandfire on Wednesday reported that a total of 65 978 t of plant concentrate was sold during the quarter, containing 16 057 t of copper. Gold sales for the same period reached 8 838 oz.