Ivanhoe tables latest Oyu Tolgoi reserves

Vancouver — Previous resource calculations on Ivanhoe Mines‘ (IVN-T, IVN-N) planned open-pit deposits at Oyu Tolgoi, in southern Mongolia, have been upgraded to the reserve category.

Proven and probable open-pit reserves on the Southern Oyu deposits are estimated at 930 million tonnes grading 0.5% copper and 0.36 gram gold per tonne, or a 0.73% copper equivalent. Recoverable metals are pegged at about 8.9 billion lbs. (over 4 million tonnes) copper and 7.6 million oz. gold.

The independent calculation by Australian engineering firm GRD Minproc assigned a block value net smelter return of US$9.05 per tonne for the reserves using metal prices of US$1 per lb. for copper and US$400 per oz. for gold.

Ivanhoe continues development drilling on its Hugo Dummett deposits to upgrade inferred material to the measured and indicated category. A revised global resource estimate is anticipated soon and will include the Hugo North deposit and the Hugo North Extension, which continues onto Ivanhoe’s joint-venture Shivee Tolgoi property with Entre Gold (ETG-V, EGI-X).

A re-tabulated resource calculation by AMEC on the Southern Oyu deposits resulted in a 1.12-billion-tonne measured and indicated resource averaging 0.48% copper and 0.35 gram gold (0.7% copper equivalent). AMEC’s revised pit shells were calculated using a lower 0.3% copper-equivalent cutoff and higher metal prices of US$1.15 per lb. copper and US$450 per oz. gold. The revised estimate shows 52% and 26% increases in contained copper and gold, respectively, over the mid-2005 resource calculation, which employed a 0.6% copper-equivalent cutoff.

Last year’s estimates also identified 582 million tonnes of indicated resource in the deeper Hugo Dummett deposits grading 1.89% copper and 0.41 gram gold (2.15% copper equivalent) using the 0.6% copper-equivalent cutoff. Further inferred resources of 1.07 billion tonnes of 1.07% copper and 0.21 gram gold (1.2% copper equivalent) were also outlined.

Ivanhoe is planning an average annual output of more than 1 billion lbs. (450,000 tonnes) copper and 330,000 oz. gold at Oyu Tolgoi over a mine life of at least 35 years, as outlined in an integrated development plan tabled last fall.