Starter Project. The Zone 5 Starter Project will average 50,000 tonnes per annum copper and +1.4 million ounces per annum silver*. Zone 5 development is designed initially as a 10,000 tonnes per day / 3.6 million tonnes per annum underground mine accessed by three interconnected underground mines along strike. The stratiform Cu-Ag mineralization is ideally suited to large scale, mechanized sub-level open stoping with the ore zone dipping ~60°, and averaging a width of 9-10 meters over 4,200 meters of strike length. The hanging wall and footwall of the ore zone are competent sandstones, and backfill will not be required. The mine will produce ore at an average fully diluted head grade of 1.75% Cu and 16 g/t Ag*, which will be hauled to Boseto for treatment.
The Boseto concentrator will be upgraded from its current 3.0 million tonnes per annum nameplate capacity to 3.6 million tonnes per annum to treat the Zone 5 ores. The ores respond well to conventional sulfide flotation, producing a high-grade ~42% copper concentrate. The concentrate will be road hauled to port for shipping and sale on the international market.
Expansion Project. The Zone 5 Expansion Project targets 80,000 tonnes per annum copper and +2.4 million ounces per annum silver. Prefeasibility work indicates that the Zone 5 mine is capable of producing ore at a rate of over 6 million tonnes per annum through mine expansion with additional declines. Trade-off studies are underway to assess the merits of adding a new processing plant to complement Boseto, versus one large new facility.
Infrastructure and Services. In addition to the existing sulfide concentrator, the Boseto property provides a wellfield for process water (+10,000 cubic meters per day), tailings dam, power plant (18 megawatts), workshops, stores, offices, and on site accommodations. Development of the North West Transmission Grid Project by the Botswana Power Corporation is expected to commence in the first half of 2017 and deliver commercial grid power to the project site in mid 2019.
Low Cost Near-Term Production. Production is scheduled to commence in 2019, with estimated capital costs of approximately $350 million for the Starter Project. The estimated mine life is 27 years, and C1 cash costs over the life of mine are estimated at approximately $1.00 per pound of copper.
* Based upon first 10 years of average production.
Zone 5 Underground Mine Design