Rio Tinto’s three diamond-mining operations yielded 2.787 million carats in the third quarter, a 54 percent decline from the third quarter of 2008, but an increase of 118 percent over the second quarter.
The Argyle Diamond Mine
In the first nine months of the year, production fell 31 percent to 9.575 million, the multi-commodity miner reported in its third quarter 2009 operations review.
The majority of Rio Tinto’s production, 2.274 million carats, came from its fully owned Argyle mine. This is a 51 percent year-over-year decline but a 457 percent leap compared to second quarter production.
According to the company, third quarter production at Argyle, “recovered from the planned maintenance shut[down] at the processing facilities,” which took place between March and May. On a carats per ton (cpt) basis, Argyle’s production grade stood at 1.55 cpt.
Rio Tinto’s 60 percent share of production at Diavik totaled 497,000 carats, a sharp 64 percent decline compared to the third quarter of 2008 and a 42 percent rise compared to the second quarter of 2009. Diavik maintained its high diamond grade, standing at 4.45 cpt in the quarter.
Third quarter production at Diavik was hampered by the six-week summer shutdown that took place in July and August. The effects of the shutdown were partly mitigated by ore being sourced from the higher-grade A154 pipe, the company said.
Diavik is expected to produce between five and six million carats of rough diamonds in 2009. This will be split on a 60/40 basis with Harry Winston Diamonds.
The company’s 77.8 percent share of production at Murowa in Zimbabwe was 17,000 carats, down from 58,000 mined last year. Murowa had a low production grade of 0.24 cpt, which was offset by the mine’s high value goods.