Iamgold updates reserves at Sadiola Hill

Markham, Ont.-based Iamgold (IMG-T) has updated the reserve and resource estimates of its three major gold assets in Mali.

The most prized of these is the Sadiola Hill open-pit mine, which is owned 38% by Iamgold, 38% by operator Anglogold (AU-N), 18% by the Malian government, and 6% by International Finance Corp.

In 1998, Sadiola Hill produced 506,113 oz. gold at a total cost of just US$126 per oz.

Proven and probable reserves, including surface stockpiles, are now estimated at 32.6 million tonnes of oxide and sulphidic saprolite ores grading 3.4 grams gold per tonne, representing 3.5 million oz. gold.

The reserves, calculated using a cutoff grade of 1.1 grams gold and a gold price of US$300 per oz., are based on an original 1995 resource base depleted as of Dec. 31, 1998.

Sadiola’s revised resource base, calculated at a cutoff of 1 gram gold, totalled 106.4 million tonnes of oxide, sulphidic saprolite and hard sulphide ores grading 2.4 grams gold, representing 8.2 million contained ounces gold. Of this total, 44.6 million tonnes averaging 3 grams gold are contained in the measured and indicated categories and in surface stockpiles. The resources also include a 700-metre extension north of a planned pit boundary incorporating Farabakouta North.

The reserve and resource statement was prepared by the mine and audited by Anglogold.

A revised reserve calculation will be performed following the completion of metallurgical tests. These tests are designed to enable mill operators to differentiate between partly refractory sulphidic saprolites, which have a 70% recovery, and less refractory sulphidic saprolites, which return higher recoveries. Currently, all sulphidic saprolites are assumed to be partially refractory. The calculation is expected by mid-year.

Iamgold and Anglogold have also revised the resource estimate for their equally owned Yatela deposit, 25 km from Sadiola. Resources at Yatela have been lowered slightly to 19.7 million tonnes grading 3 grams gold (1.9 million contained ounces) at a cutoff grade of 1 gram gold.

The partners’ third prospect is the Alamoutala gold deposit, 13 km north of Sadiola. Inferred resources at Alamoutala remain unchanged at 2 million tonnes of soft oxide grading 2.5 grams gold (160,000 contained ounces) at a cutoff of 1 gram gold.