Modern Mining July 2019

COUNTRY FOCUS: BOTSWANA

installation of a scalping screen and a product screen,” Ferreira explains. “We will also be undertaking a metallurgical upgrade, which will include changing the flotation circuits, install- ing a high-intensity regrind mill, replacing the filter press and adding a new concentrate thick- ener and a new bagging unit. In general, the plant is in good shape although some structural and corrosion repairs will be required.” The processing plant will produce a high- grade (approximately 40 % Cu) concentrate that will be delivered to African and international smelters, with the first shipment expected to be despatched in Q2-2021. Although the main driver of the project is copper, the silver output is by no means insignificant and will account for around 7 % of revenue. Most of the major contracts for the Starter Project have already been awarded with Concor being responsible for the access and haul roads and Kalcon, part of the WBHO Group, the box- cuts. One of the biggest contracts of all, the five-year underground mining services contract, was awarded in late June this year to Barminco, a subsidiary of ASX-listed Ausdrill. The con- tract is worth approximately US$560 million and is due to start in December this year. With respect to the Boseto processing plant, Fluor

system designed to improve stope productiv- ity. The mine will be highly mechanised and automated with remotely controlled equipment extracting ore from the stopes. We are not pio- neering, however, and all the technologies we are proposing to use are well-established and available commercially right now.” The three boxcuts required for the three decline systems form a substantial part of the work programme, with the excavations being from 50 to 52 m deep, 600 to 800 m long and 300 to 500 m wide. The boxcuts are designed to be inherently stable and safe from a geotech- nical point of view but – with the first 30 m being in Kalahari sand – geocells with soilcrete are being used to prevent erosion of sand into the excavations. Work on all three boxcuts started in March this year with the first boxcut due to be completed in November (2019) with handover of the other two following at roughly one-month intervals. Ore mined at Zone 5 will be hauled to the Boseto plant over a sealed 35 km long road using 150-tonne capacity trucks. To accommo- date the planned level of production from the Zone 5 mine, the plant will have to be upgraded to a capacity of 3,6 Mt/a (10 000 tonnes per day). “The volumetric upgrade will involve the

Ore from the Zone 5 mine will be treated in the Boseto concentrator, which is to be upgraded to a capacity of 3,6 Mt/a.

Kalcon earthmoving machines working in the south boxcut.

32  MODERN MINING  July 2019