African Barrick Gold is adding a new 2.4-million-mt/y carbon-in-leach circuit at its Bulyanhulu processing plan in northwest Tanzania. The new circuit will provide for hydraulic reclamation of the current tailings storage facility and simultaneous treatment of all current flotation tailings through a purpose-built plant. An existing 300,000-mt/y plant will be decommissioned following the start-up of the new plant.
Feed for the new plant for the first six years will be made up of the historical material reclaimed from the tailings storage facility and from cleaner and rougher tailings generated at the existing flotation plant. The tailings storage facility has an indicated resource of 8 million mt at a grade of 1.23 g/mt, for 315,000 oz of contained gold. Once the tailings facility is exhausted, the plant will process the flotation circuit tailings, supplemented by lower-grade rougher tailings stockpiles (approximately 1.9 million mt at a grade of 0.65 g/mt), which will be created in advance of the expansion.
A new life-of-mine tailings storage facility will be constructed for future tailings at Bulyanhulu, which requires an Environmental and Social Impact Assessment but does not impact the project timetable.
The project will add more than 40,000 oz/y to Bulyanhulu gold production during its first six years of operation, beginning in the first half of 2014, and further incremental production for the remainder of the mine life. Added life-of-mine production will total about 576,000 oz at a total cash cost of $554/oz.
Pre-production capital investment for the project is estimated at $167 million, inclusive of contingency, and life-of-mine sustaining capital is estimated at $18 million. Site works were scheduled to begin by the end of July 2012. Construction of the plant and associated infrastructure, together with commissioning, is expected to take up to 18 months.
In mid-May, African Barrick reported it had concluded discussions with the Tanzanian government with respect to the level of royalty payments made by its operations and, in light of the current gold price environment, agreed to a voluntary additional 1% royalty going forward. This is in addition to the 3% rate stipulated in the company’s mineral development agreements, which remain unchanged.