Copper-in-concentrate production in 2016 from the Toromocho mine in Central Peru would likely be 6.6%-12.1% lower than the 182,000-mt target previously set, the project owner Chinalco Mining Corporation International said Wednesday.
The downward revision in production guidance is due to the complexity and the high oxidation rates of ores mined from the project's open slope area this year, the company said in its 2016 interim results announcement filed to the Stock Exchange of Hong Kong.
Recovery rates have been affected and production of copper concentrate may decrease in 2016, the company said. But it also added that the long-term production from the Toromocho mine will not be materially affected.
The Toromocho mine, which started production in June 2015, is expected to produce about 800,000-890,000 mt of copper concentrate, with copper contained at 160,000-170,000 mt, in 2016. The previous output guidance was 182,000 mt of copper contained in 764,000 mt of copper concentrate.
According to the interim report, the mine produced 378,000 mt of copper concentrate in the first half of this year, with 73,801 mt of copper and 2.33 million oz of silver contained in the concentrate.
The January-June copper output only amounts to about 43.4%-46.1% of the company's revised guidance for 2016.
During the reporting period, Chinalco-CMC, the overseas mining arm of Chinese state-owned aluminum conglomerate Aluminum Corporation of China, mined 49 million mt of material from the Toromocho mine and milled 17 million mt of ore.
Chinalco-CMC did not produce any molybdenum in the first half of this year, as it plans to conduct experimental research to identify a separation process that could improve the recovery of molybdenum content from the copper concentrate.
With an estimated mine life of 32 years, the Toromocho project consists of an open-pit mining operation with daily ore processing capacity estimated to reach 117,200 mt.
Looking back at the first half of this year, Chinalco-CMC said worldwide economic stimulus as well as delay of the US Federal Reserve in raising interest rates had helped trigger a rebound in international copper prices to a four-month peak of $5,131/mt in mid-March, from this year's low of $4,318/mt in February.
With China's copper imports reported to have surged 22% year on year in the first half, Chinalco-CMC said it remained "cautiously optimistic" that Chinese demand would provide market support and bring copper prices back to an average of $4,900/mt for the whole of 2016 from a $4,701/mt average in January-June.