Rio Tinto (RIO) has reaffirmed full-year production guidance for its Oyu Tolgoi mine but is still in discussions with Chinese customs officials to allow customers to collect copper concentrate they have bought.
In a statement, Rio subsidiary Turquoise Hill Resources, which owns 66% of the Mongolian mine, said it produced 30,600 tonnes of copper in concentrates in the third quarter of 2013.
Over the first nine months of 2013, the mine produced 43,700 tonnes of copper in concentrates.
The mine is now operating at nameplate capacity of approximately 100,000 tonnes of ore processed per day after continuing to ramp up in the third quarter.
The miner reiterated forecasts of 75,000 to 85,000 tonnes of copper in concentrates produced for 2013.
Oyu Tolgoi also produced 62,000 ounces of gold in concentrates and 196,000 ounces of silver in concentrates in the third quarter.
Over the first nine months of 2013, the mine produced 83,000 ounces of gold in concentrates and 281,000 ounces of silver in concentrates.
Ore grades and recovery rates are expected to keep improving through the fourth quarter as the mine is still in an early stage of development.
Turquoise Hill chief executive officer Kay Priestly said concentrate shipments began early in the quarter.
"Oyu Tolgoi's customers are making good progress with Chinese customs officials to resolve matters with purchased concentrate at the border," Ms Priestly said.
Turquoise Hill warned of the delay last month, saying Oyu Tolgoi concentrate is the first of its kind to be shipped across the Gangquimadou bilateral border between Mongolia and China.
The Mongolian government owns a minority stake in the mine.