HomeBase MetalsMammoth and mechanised: The beauty of Khoemacau

Mammoth and mechanised: The beauty of Khoemacau

2021 marks a significant milestone for the Khoemacau copper and silver project in Botswana – production start-up.

While it represents the introduction of a new, large-scale and fully mechanised operation in the country, the long-term vision is to double production, at the very least, JOHAN FERREIRA, CEO at Khoemacau Copper Mining tells LAURA CORNISH.

This article first appeared in Mining Review Africa Issue 11, 2020
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The 100% owned Khoemacau copper project is situated within the widespread Kalahari Copperbelt and forms part of a 4 040 km² land package that Khoemacau Copper Mining owns.

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This area is home to what has already been proven to contain significant quantities of copper and silver and represents what Ferreira believes will in time become a significant copper producing mining complex, diversifying the Botswana mining industry.

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For now, the privately owned company is focusing on the development of the “Starter Project” which includes Zone 5, a Greenfield underground complex, supplying ore to the existing Boseto processing facility, currently undergoing an upgrade.

Comprising a measured, indicated and inferred resource of 92 Mt of copper containing high-grade 2.2% copper and +22 g/t of silver, Zone 5 will deliver 3.65 Mtpa of ore to the Boseto processing facility which will produce +60 000 tpa of copper and 2 Mozpa of silver (in concentrate).

“We are on track to commission and deliver first concentrate towards the middle of 2021 and will ramp up to steady-state within six months,” says Ferreira. “At this point, we are in a position to produce comfortably at these quantities for 24 years, just from Zone 5.”

Firing on all cylinders

With a critical timeframe that required full steam construction activity in 2020, Khoemacau has only been modestly impacted by the COVID-19 restrictions introduced by government in Botswana.

“Despite a reduced workforce and need to observe safety protocols, we have managed to keep the mine development on track and had seen modest impacts on the process plant upgrade schedule.

Fortunately, we have been declared an essential service in the country, enabling us to proceed with development and construction activities,” Ferreira notes.

Looking at the mining operation itself, Zone 5 comprises three adjacent underground mines that are divided into specific corridors and referred to as north, central and south mines – each designed to deliver on average 1.2 Mtpa of ore to the plant.

The ore body’s sulphide material starts 100 m below surface and extends for 1.2 km downwards – as far as Khoemacau has drilled for now.

“Each mine comprises an innovative twin decline system which provides a wider strike length exposure to the ore body, and facilitates the production flexibility we require, but further offers independent ventilation, power supply, etc. This equates to three independently operating mines,” Ferreira outlines.

From a development perspective, Khoemacau has made quick work of its development targets. Having commenced with box cut excavation in 2019, the CEO confirms (as of mid-2020) that all box cut construction was complete and over 5 000 m of development concluded since the start of underground mining in February 2020.

Subsequent to this, development of the first ore blocks is in process and first ore is already on surface. A small amount of supporting surface infrastructure work is scheduled to be completed by the end of 2020.

Australia-based mining contractor Barminco is not only undertaking all development work for the project but will mine all three underground mines as well – using fully mechanised processes.

“This will be the first highly mechanised operation in Botswana, unlike anything southern Africa has seen before. All ore from our stopes will be remotely loaded without any person in the operating cabins and our jumbo drill rigs will operate without any direct human interface – an investment driven by our objective to run a safe, healthy, sustainable and productive mine,” Ferreira states.

The company’s commitment to safety is further illustrated by the performance to date, with only one LTI since commencement of construction and mine development, despite a very large construction workforce of over 2 500 people on site.

“Through the delivery of a large-scale, underground mechanised mine, Khoemacau will start to build a long-lasting legacy in Botswana.”

The existing Boseto processing plant, which formed part of the acquisition of the Boseto mining operation, which Khoemacau acquired out of provisional liquidation in 2015, is the other critical path area.

It is being volumetrically and metallurgically upgraded with demolition, civil, structural, mechanical, sand blasting and painting construction activities in progress.

Electrical and instrumentation works are ready to start. “Once completed, the plant’s capacity will increase from 3 Mtpa to 3.65 Mtpa and will offer an enhanced flotation circuit, a new HIG mill, Jameson cells and filtration plant as well as refurbishment to the entire facility,” says Ferreira.

Through the Boseto acquisition, Khoemacau also gained access to an existing tailings storage facility which will be upgraded as part of the project and then utilised once the process facility is in production, and a large package of prospecting licenses.

The supporting infrastructure required for Khoemacau’s development and production requirements includes the Zone 5 infrastructure (offices and workshops), emergency diesel power generation, 50 km of a 132 kV overhead transmission line that distributes the power requirements to the mine site, from the Botswana Power Corporation national grid, two new sub-stations, a 40 km water pipeline that supplies borehole water to Zone 5, the occupation of the first phase of the permanent Zone 5 accommodation camp and the 35 km haul and access road that links the neighbouring Boseto processing plant to Zone 5 mine – all of which have been substantially completed.

The direct capital cost of the project is forecast at some US$400 million, in line with the company’s original budget, offering capital efficiency of $6 700/annual ton of copper, well below industry averages. With a LOM zverage C1 cash cost of $1.47/lb copper and net silver credits, this this a very competitive copper operation.  The company raised some $650 million in 2019 to fund project development, retirement of pre-construction loans, financing and overhead costs as well as working capital.

The greater potential

With a + 4 000 km² land package, 100% owned by Khoemacau, the vision for a substantial expansion is already on the cards.

“In the medium term we aim to expand our production to over 100 000 tpa of copper and 5 Mozpa of silver in concentrate and in the long term increase this even further to +150 000 tpa of copper and +6 Mozpa of silver by developing further resources,” Ferreira confirms.

Infill drilling and studies are already underway for three additional deposits including Zeta North East (15 km from Zone 5 but close to the Boseto plant), Zone 5 North (2.5 – 3 km north of Zone 5) and Mango (4 km south-west of Zone 5), along with a potential expansion of mining at Zone 5.

“Our thinking at this stage is to establish a new mill at Zone 5 – taking our total milling throughput capacity to between 8.5 and 9 Mtpa. From this point, we will feed higher volumes of ore from Zone 5 directly to the new mill and the ore from our three additional ore bodies into the Boseto process plant. Funding could come almost, if not entirely, from cash flow, but the best funding strategy will be determined,” Ferreira reveals.

“In addition to our expansion plans, we will also continue to explore our prospecting licences further.”

Lastly, considering the large-scale plans Khoemacau has in the pipeline, the company may consider elevating its status, and through an initial public offering transition from a privately-owned company to a public listed entity.