Modern Mining July 2018

COUNTRY FOCUS: BOTSWANA

regrind mill; rougher flotation cells; concen- trate storage tank; and a concentrate filter. The likelihood that the Expansion Case will eventually be the model for project develop- ment was boosted earlier this month (July) when MOD announced a substantial 44 % increase in the total mineral resource at T3. The upgraded resource follows completion of a 90-hole programme of infill and extensional diamond core drilling around the planned pit at T3. Assuming a 0,4 % cut-off grade, the total revised resource tonnage now exceeds 60 Mt – with around 70 % in the indicated category – and contains approximately 590 kt of copper. Commenting on the resource upgrade, MOD’s Managing Director, Julian Hanna, said that it provided “further confidence in the potential for significant discoveries that may exist in similar ‘buried domes’ within the T3 Dome complex where a major drilling cam- paign is underway.” One of these is the large A4 Dome, around 50 km to the south-west of T3, where the second hole to test the target sequence recently intersected visible copper mineralisation in veins within a zone extend- ing up to 67 m downhole width. Apart from the T3 project, MOD also has the T1 (Mahumo) underground project, in which it has a 100% interest. Located 20 km to the north- east of T3, this was the original focus of the company’s activities in the Kalahari Copperbelt. The current resource (2,7 Mt at 2,0 % Cu and 50 g/t Ag) is relatively small but MOD is currently undertaking extension drilling, the objective being to delineate a resource of at least 10 Mt. It is envisaged that if T1 is developed as an underground mining operation, its ore could be processed at the proposed T3 plant. Hanna and Kelemogile Tau, Exploration

mined from a single, four-stage open pit with a waste to ore ratio of 4,76 using conventional hydraulic excavators and rear dump trucks. It is envisaged that a contractor would be employed to undertake the mining under the technical and managerial direction of MOD. The processing route selected comprises a con- ventional SAG/ball mill and flotation circuit which would process run-of-mine (ROM) ore to produce a copper concentrate and tailings. Concentrate would be thickened, filtered and stockpiled prior to being loaded into 2 tonne bulk bags for storage and subsequent transport to third-party smelters. The Expansion Case considers mining and processing at a rate of 2,5 Mt/a for the first three years as per the PFS Base Case. The pro- cess plant would then be upgraded to be able to process at a rate of 4,0 Mt/a during the fourth year. Mining would be from a single, five-stage open pit with a waste to ore ratio of 4,28. The optimised pit was modelled as per the Base Case except for the inclusion of inferred mineral resources and

The 3 Mt/a Boseto concen- trator, seen here, will process the ore from Khoemacau’s Zone 5 mine. It was commis- sioned in 2012 and operated at spec when fed with 1 % sulphides. It will be up- graded to a throughput of 3,6 Mt/a – at approximately 2 % Cu – to treat the Zone 5 ore (photo: Arthur Tassell).

Disseminated T3 copper ore (photo: MOD Resources).

the reduction in processing costs due to grid power. Processing would be through the Base Case conventional SAG/ ball mill and flota- tion circuit for the first three years. The process plant would then be upgraded – at an estimated capex of US$37 million – to process 4,0 Mt/a by the addition of a scats crush- ing circuit; rougher concentrate

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36  MODERN MINING  July 2018