Sunridge Gold, a Canadian junior company headquartered in Vancouver, has announced completion of a feasibility study for its Asmara copper-zinc-gold-silver project in Eritrea. The study contemplates three stages of development to mine four deposits—Emba Derho, Adi Nefas, Gupo Gold, and Debarwa—all located within 25 km (15 miles) of Eritrea’s capital city, Asmara. Ore would be processed at a facility near the large Emba Derho deposit.
Phase 1A of the Asmara project, during years one and two of operations, would be based on the mining of 116,000 mt of high-grade direct shipping ore from the Debarwa deposit at average grades of 15.6% copper, 2.96 g/mt gold, and 76.8 g/mt silver.
Phase 1B, during years one to five, would entail mining 3 million mt of near-surface gold caps at Debarwa and Emba Derho followed by Gupo Gold. Processing would be at a gold heap-leaching operation near Emba Derho at a rate of 1.4 million mt/y. Grades would average of 1.48 g/mt gold and 8.2 g/mt silver, and recoveries would average 66.7% gold and 37.7% silver.
Phase II, during years two to 3.25, would be based on mining and flotation processing of 2.4 million mt of high-grade copper supergene ore from the Debarwa and Emba Derho deposits at a rate of 2 million mt/y. Phase II grades would average 2.25% copper, 0.76 g/mt gold and 21.6 g/mt silver, and recoveries would average 79% copper, 51% gold and 58% silver.
Phase III would be based on mining and flotation processing of 51 million mt of primary copper and zinc ore from Emba Derho, Debarwa, and Adi Nefas at a rate of 4 million mt/y for 13 years. Emba Derho and Debarwa would be mined from open pits and Adi Nefas would be mined from underground. Phase III grades would average 0.73% copper, 1.91% zinc, 0.36 g/mt gold and 12.6 g/mt silver, with recoveries of 86% copper, 86% zinc, 48% gold and 44% silver.
Annual metal production during the first eight years of Asmara project operations is expected to average 65 million lb of copper, 184 million lb of zinc, 42,000 oz of gold, and 1 million oz of silver.
Initial capital costs for Phase I direct shipping ore and heap-leach development at Asmara are estimated at $46 million. Expansion capital for Phase II and Phase III is an additional $357 million. Additional capital requirements over the life of the mine are estimated at $227 million, and closure costs are estimated at $36 million.
When the Asmara project mining license is granted, the government of Eritrea will have a 10% carried interest in the project and ENAMCO (Eritrean National Mining Corporation) will purchase an additional 30%. ENAMCO will be responsible for 33.33% of all capital and operating costs of the mine.
The Asmara project feasibility study is NI 43-101 compliant and was completed by lead engineering company SENET. Snowden Group participated in mine design and mine planning, and Knight Piésold Ltd. worked on water and waste management. Blue Coast Metallurgy Ltd. directed metallurgical test-work.
Next steps for Sunridge include completing required environmental studies, applying for the mining license, arranging debt financing, commencing detailed engineering work, and hiring new key employees.