Modern Mining July 2016

COUNTRY FOCUS BOTSWANA

large diamonds immediately post the primary crusher. Both projects – which involve an esti- mated investment of between US$15 million and US$18 million – were in detailed engi- neering design with the procurement of long lead items in place, he said. Updating delegates on Karowe’s performance this year, Day said the mine had produced 165 diamonds larger than 10,8 carats at an average stone size of 27,9 carats during the first quar- ter. Of these, eight were larger than 100 carats (compared to six in this range in Q1 2015). Lucara’s guidance for 2016, he said, was for revenues of US$200 to US$220 million (exclud- ing the sale of the 813-carat diamond and the possible sale of the 1 111-carat diamond). The mine was expected to process between 2,2 Mt and 2,4 Mt of ore over the year to produce over 350 000 carats at an operating cash cost of between US$33,50 and US$36,50 per tonne. Finally and turning to exploration, Day told delegates that Lucara – via Boteti – had been awarded two precious stone prospecting

and which, collectively, are able to treat approximately 415 t/h. A sixth Tomra machine is on site but is used in an audit application on the tailings stream. Advantages of the XRT technology include its compact footprint, low operating costs, high recovery rates and extremely low concentrate yields. There is no need to further process the concentrate from the sorters before final hand sorting. Day believes the Karowe installation can claim to be the first in the world in terms of primary diamond recovery although XRTs have been used to treat recovery tailings in some operations. In his presentation in Gaborone, Day said the LDR was able to recover diamonds of well over 1 000 carats – as had been proven in the case of the 1 111-carat stone. He said that such was the success of the XRT installation that Lucara had now embarked on a project to increase the top size of diamonds recover- able by the LDR and was also installing a new Mega Diamond Recovery circuit to recover

Boteti Mining personnel in the Karowe pit. Current mining operations are concentrated on the central and south lobes of the AK6 kimberlite.

A Cat 992G loads a Terex TR100 dump truck. The mining contractor at Karowe is MCC.

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July 2016  MODERN MINING  43