Modern Mining July 2016

COUNTRY FOCUS BOTSWANA

is 3 Mt/a and Cupric believes it can easily be upgraded to treat 3,65 Mt/a. This will involve the repair, modification and enhancement of some existing circuits, as well as additions such as a new secondary cone crusher, increased flo- tation capacity and a new concentrate filter. While Cupric’s planning is based on the proj- ect being connected to the Botswana electricity grid when it comes on stream in 2019, Boseto does have its own diesel-powered 18 MW power plant which will be adequate (once its capacity is increased to 22 MW) to allow opera- tions to start up should there be any delay in establishing this connection. The Boseto site is also served by a plus 10 000 m 3 /day wellfield which – again with some expansion – will sup- ply all the water the plant requires. The underground mine at Zone 5 will involve the development of three declines – the Central, North Central and North declines. The mining method to be used will be sub-level open stoping (SLOS). As Tsimako pointed out, a number of mining methods were examined by the project team including sub-level cav- ing, shrinkage stoping, cut-and-fill stoping and top slicing, with SLOS emerging as the prefer- able method. He noted that the declines would be developed from boxcuts providing access through 40 m of Kalahari sand. Breaking down the project schedule, Tsimako said work would start on the box- cut and infrastructure development in 2017 with mine development following later in the year and the concentrator upgrade beginning in H2 2017. The first concentrate, he said,

recent drilling programme Cupric on occasion had up to 27 diamond rigs – from as many as four different drilling contractors – active at Zone 5. Tsimako said that the Starter Project is the initial phase of what Cupric calls the ‘Hybrid Project’ – the combination of the Zone 5 deposit with the Boseto assets – and would comprise an underground mine at Zone 5 with the ore being trucked to Boseto for processing in the upgraded and expanded concentrator plant at a rate of 10 000 tonnes/day or 3,65 Mt/a to pro- duce approximately 50 000 t/a of copper and 1,2 Moz/a of silver contained in a high-grade (approximately 42 % Cu) concentrate. Tsimako told delegates that operating costs would be in the region of US$37/tonne of ore processed. The current capacity of the Boseto plant

Core shed at the Zone 5 site.

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Mining sequence for the Zone 5 mine

34  MODERN MINING  July 2016