PERTH (miningweekly.com) – ASX-listed Oz Minerals has upped its copper production expectations following a strong June quarter.

The miner on Tuesday reported that copper production during the three months to June had exceeded expectations, with the company producing 22 181 t, while gold production reached 30 736 oz at its Prominent Hill operation, in South Australia.

This was compared with the 18 182 to of copper and 33 792 oz of gold produced in the previous quarter.

Oz Minerals told shareholders that strong mining rates at the Malu openpit operation had been maintained for the third successive quarter and these, along with the consistently good contribution from the Ankata underground operation and the high mill availability, had driven the higher-than-expected production.

With the year-to-date copper production now standing at over 40 000 t, Oz Minerals estimates that full year copper production would be higher at between 85 000 t and 90 000 t, rather than the previous estimate of between 75 000 t and 80 000 t.

As a result of the higher proportion of copper ore and the lower proportion of gold-only ore expected in the mill for the remainder of the year, Oz Minerals has maintained its gold production guidance for the full 2014 at between 130 000 oz and 140 000 oz.

Cash costs would likely reduce to between $1.10/lb and $1.20/lb, rather than the previous estimate of between $1.15/lb and $1.25/lb, reflecting the higher copper production and the lower openpit mining unit costs, which would be offset to some extent by lower gold by-product credits and the higher ore milled than previously assumed.

Meanwhile, Oz Minerals also reported on Tuesday that 45 358 t of copper concentrates were shipped during the three months to June, containing 22 417 t of copper, 33 799 oz of gold and 222 176 oz of silver.

In the first half of the year, 76 529 t of copper concentrate was shipped, containing 37 453 t of copper, 69 562 oz of gold and 343 183 oz of silver.