Modern Mining June 2015

MINING IN AFRICA

production, with a start already having been made on the rehabilitation. The PEA on this project contemplates a 500 tonnes per day (tpd) underground mining operation extracting high grade ore from the West Reef section of Prestea underground. High grade ore will be trans- ported along the existing dedicated haul road to the Bogoso plant and a new 500 tpd gravity-CIL plant will process the material. Initial capital costs of the development were estimated in the PEA at US$41 million. Prestea underground will have a five-and-a- half year life during which 649 000 tonnes of ore at 17,2 g/t will be mined. Mining operations should start next year with a peak gold produc- tion of 91 000 ounces being achieved in 2018. Another long-lived Ghanaian mine which could get a new lease of life is Bibiani , which has produced more than 4 Moz of gold since mining operations first began in the early 1900s. Although it has historic underground workings to 800 m depth, it has been mined by open-pit methods in recent years and has a 3,4 Mt/a CIL plant in place. Last year Resolute Mining acquired the mine – by then under care and maintenance – from Noble Mineral Resources and is planning to reopen it as an underground operation. A feasibility on the underground mine is currently in progress. Côte d’Ivoire – the new gold frontier In Ghana’s immediate neighbour to the west, Côte d’Ivoire, which is sometimes described as West Africa’s new gold frontier, the mining

is already well advanced with construction of the 3 Mt/a, US$295 million Phase 1 Obotan project, with the first gold expected in the first quarter of 2016. Phase 1 will deliver 190 000 ounces of gold a year but the Phase 2 (Esaase) project will more than double this to a total pro- duction of 411 000 ounces a year. While most of the mines developed in Ghana in recent years have been open-pit oper- ations, the country does have a long tradition of underground mining. One company which is planning new underground operations is Golden Star Resources (GSR), whose CEO is a South African-trained mining engineer, Sam Coetzer. Listed on the NYSE and TSX, GSR owns the Wassa, Prestea (inactive at present) and Bogoso mines in Ghana and in 2014 pro- duced 261 000 ounces of gold from Wassa and Bogoso. Wassa is currently an open-pit mine but its operations are to be supplemented by an under- ground operation. This is costing a modest US$39 million to develop with first production expected early next year and commercial pro- duction in July 2016. Production will continue through to 2024. At steady state production, the Wassa underground mine is expected to pro- duce an average of approximately 2 000 tonnes per day and will allow the combined Wassa open-pit and underground operations to pro- duce an average of 163 000 ounces a year over the life of mine. GSR is also working at bringing the more than 100-year-old Prestea mine back into

The Yaoure project site in Côte d’Ivoire. Yaoure is owned by London-listed Amara Mining, which claims that the deposit is the largest gold development project in West Africa. As can be seen here, the deposit has been mined in the past (photo: Amara Mining).

feature

June 2015  MODERN MINING  37