Tag Archives: Kalahari Copper Belt

Perenti boosts Botswana portfolio with Sandfire Motheo copper project contract

Perenti Global Ltd says its surface mining business in Africa, African Mining Services (AMS), has been awarded the contract for open-pit mining services at Sandfire Resources’ Motheo copper project in Ghanzi, Botswana.

The contract, which is yet to be finalised, has an estimated value of $496 million over an initial seven-year-and-three-month term with a provision for a one-year extension.

Under the terms of the Mining Services Contract, AMS will identify a suitable local Botswana company or companies as a joint venture partner for the project and transition to the joint venture before the commencement of mining in early 2022.

Finalisation of the contract is contingent on the satisfaction of two primary conditions, namely Sandfire being granted a mining licence for the project; and finalising the terms of the Mining Services Contract.

Perenti Managing Director and Chief Executive Officer, Mark Norwell, said Motheo represented a game-changing growth opportunity for AMS and will substantially increase Perenti’s presence in Botswana.

“Growing our footprint in Botswana is aligned with our 2025 strategy, to further expand into stable mining jurisdictions and pursue quality projects. The benefit of adding Motheo to the Perenti project portfolio is the opportunity to leverage our existing in-region operational presence at Zone 5 (owned by Khoemacau Copper Mining) as well as partnering with Sandfire to develop Botswana’s next large-scale, highly productive, world-class copper mine.

“The Motheo project is another positive step in the ongoing transformation of our AMS business as we seek to create value and certainty for our client Sandfire and the Ghanzi community.”

Motheo is in the Kalahari Copper Belt, an emerging and relatively underexplored copper producing region. It is around 200 km to the southwest of the Khoemacau Zone 5 project, where Perenti, through its subsidiary Barminco, is currently engaged to undertake underground mine development works.

Motheo is held through Sandfire’s subsidiary, Tshukudu Metals, and was approved for development by Sandfire’s Board of Directors in December 2020 following completion of a definitive feasibility study (DFS) on a base case of a 3.2 Mt/y operation with expansion potential.

The DFS outlined an initial 12.5-year operation, underpinned by an updated ore reserve of 39.9 Mt at 0.9% Cu and 12.2 g/t Ag for 360,000 t of contained copper and 15.6 Moz of contained silver, producing on average circa-30,000 t/y of contained copper and 1.2 Moz/y of contained silver over the first 10 years of operations.

Perenti Mining Chief Executive Officer, Paul Muller, said: “Through this commitment and the establishment of a local joint venture partnership, we expect that more than 95% of the workforce will be citizens of Botswana. Furthermore, and leveraging our existing Maun based state-of-the-art mining training centre, our workforce will have access to the latest mining techniques and technology to enable the creation of a safe, highly skilled and productive workforce to support economic growth and diversification within Botswana.”

Muller said the company was also excited by the opportunity to deploy “future-focused mining technology initiatives” on the project that not only provide expected productivity and safety benefits to Sandfire but are also aligned with the two firms’ sustainability goals.

Perenti anticipates pre-production work to commence in late 2021 with mining to commence in early 2022.

Concor Infrastructure closes in on Khoemacu copper-silver project milestones

Concor Infrastructure says it is nearing completion of a 35 km access road for the Khoemacau Copper Silver Starter project in the Kalahari region of Botswana.

The company is at the same time also busy with constructing a parallel haul road, as well as conducting earthworks and concrete civils at the Khoemacau Boseto processing plant.

The Khoemacau copper project, in the central Kalahari copper belt, is developing underground operations at its flagship Zone 5 deposit. The mine plan involves three adjacent underground mines at Zone 5, each producing over 1.2 Mt/y in their first five years of production.

The haul road in question will allow mineralised material to be trucked 35 km from Zone 5 to the Boseto processing facility, while the access road will be used by light vehicles. After processing at Boseto, the mineral concentrate will be shipped out for smelting.

Good progress has been made on construction of the access road according to Jay Juganan, Contracts Director at Concor Infrastructure. The contract for both the access and haul roads was awarded in November 2018.

“The access road was little more than a sand track when we established on site and was accessible only by 4×4 vehicles,” Juganan says. “Essentially, we are creating a corridor for both roads in parallel, and for the powerlines to be installed by another contractor.”

The planning of the haul road also had to consider the large and ancient Baobab trees that are common in the area. Preservation of these trees is a vital imperative, requiring the haul road to be diverted on occasion to avoid about half a dozen Baobabs, which are hundreds of years old.

The access road is 90% complete and due for completion in the September quarter. The haul road is also expected to be completed next quarter, the company said.

Road construction comprises a 600 mm deep cut filled with pioneer crushed rock followed by a G3 sub base and base layer. In some areas, the crushed rock is replaced by a natural calcrete.

The wearing course is a 9/19 mm double seal, according to Concor, which had to crush all aggregate on site from the old mine waste rock stockpile at Boseto.

Concor Infrastructure Contracts Manager, Tiaan Krugel, said the remote location of the site and the dry conditions are among the key challenges encountered on this project.

“The sourcing and timing of the supply of equipment, parts and construction material required careful and detailed planning,” Krugel says. “The majority had to come from the capital Gaborone – 900 km away – with the other challenge being that most of our equipment OEMs are based in Johannesburg, which is more than 1,300 km from site.”

The scope of Concor’s work at the Boseto process plant, the contract of which was awarded in November 2019, includes earthworks and concrete civils to the existing and for the new process plant structures for the crushing, milling, flotation and concentrate handling circuits. The plant had previously treated material from an open-pit copper mining operation at Boseto, under the ownership of a different company.

Krugel highlighted the challenges of working with concrete on a remote site, especially where temperatures can reach over 40°C during working hours.

“A special concrete mix was designed to accommodate on-site conditions,” he said. “This includes the use of admixtures to prolong the concrete’s workability as well as having to chill the water we use before it is added to the cement and aggregates.”

In addition to the refurbishment and upgrading work at Boseto, Concor has also contributed to preparing the infrastructure at the Zone 5 mining site, where underground development is underway.

The work included all internal roads at the Zone 5 mine, terracing for the 650-person accommodation camp, the mine administration surface infrastructure area, the mine workshops and stores area and the explosives magazine together with construction of the ROM pads.

The Khoemacau Starter project expects to produce 62,000 t of copper and 1.9 Moz of silver each year over its planned life of more than 20 years, according to the company.

“Despite the restrictions related to the COVID-19 pandemic, which saw a reduction of staff numbers on site due to individual choices, we are working hard to ensure that program schedules will be met,” Juganan said.

MOD lays out plans for T3 copper-silver project in Botswana

The feasibility study for MOD Resources’ majority-owned T3 copper-silver open-pit project in Botswana has delivered compelling mine economics, in addition to a fleet and flowsheet plan that will interest the major mining original equipment manufacturers.

T3, in the Kalahari Copper Belt, is expected to require $182 million in development capital and deliver a mine able to produce life of mine average production of 28,000 t/y of copper concentrate and 1.1 Moz/y of silver at all-in sustaining costs of $1.56/Ib after deducting silver credits.

The pre-tax net present value (8% discount) for the project came in at $368 million based on a long-term copper price of $3.08/Ib, or $6,791/t.

The current plan would see T3 produce first product in the March quarter of 2021, operating over an 11.5-year mine life.

In terms of the primary loading fleet, the company said this would be made up of a maximum of five hydraulic excavators in the 120-250 t class. This is considered the optimal option that could achieve the required productivity, maintain a degree of selectivity when required and minimise the number of units required for practical separation of loading and hauling units, according to the company.

The ore and waste haulage fleet is expected to consist of 140 t mechanical drive haul trucks capable of direct tipping to the primary crusher.

MOD said there is step change to a lower annualised total material movement (TMM) after year five of operations. A peak TMM of 39 Mt (annualised) is due to be maintained during the first four years of the schedule, requiring 24 trucks and five excavators to ensured continuous ore supply. TMM drops to 6 Mt/y after year six and is generally maintained for the remaining life of mine, it said.

“The mining schedule has been constrained by setting a maximum vertical advance rate of 120 m/y annum to allow sufficient time for dewatering, grade control, drill and blast and load and haul,” the company said, adding that the maximum vertical lag between benches is set at 50 m.

The production schedule achieves the target process plant throughput rates both during ramp-up and during steady state operations of 3.0 Mt/y to 3.2 Mt/y (peak), it said.

The copper recovery plant and associated service facilities will process run of mine (ROM) ore delivered to a single stage primary crusher. The crushed ore will be stockpiled from where it is fed to a two-stage grinding circuit using SAG and ball milling. Copper minerals in the ground ore will be concentrated in a conventional copper flotation circuit, made up of roughing, regrind and a single stage of cleaning. Concentrate from the cleaning stage will be thickened then filtered on site prior to transporting to Walvis Bay, in Namibia. From Walvis Bay, the concentrate will be shipped to third-party smelters.

Tailing from the roughing and cleaning stages will be pumped to the tailings storage facility located south of the proposed mine. The TSF is designed to store approximately 34.4 Mt of conventional thickened tailing – enough for the 11.5 years of the project life.

The process plant is forecast to produce a life of mine annual average copper in concentrate of 28,000 t, with average grades for Cu and Ag of 30.4% and 383g/t, respectively.

The key criteria selected for the plant design are:

  • The mill will process a total of 34.4 Mt of ROM ore for 11.5 years;
  • The annual ROM treatment is 3.0 Mt/y with a peak treatment rate of 3.2 Mt/y, at a primary grind size of 80% passing 180 μm;
  • Design availability of 91.5% with standby equipment in critical areas;
  • Design copper head grade of 1.3%. This head grade allows for grade variation from the life-of-mine average grade of 1.0% Cu;
  • Eighty-fifth percentile of comminution ore properties;
  • Ore specific gravity of 2.8 t/m³;
  • Laboratory rougher flotation residence of six minutes, and cleaner 1 and cleaner 1 scavenger residence time of two minutes and eight minutes, respectively, and;
  • Rougher concentrate mass recovery of 6.2% (w/w) for regrind circuit sizing and final concentrate mass recovery of 3.6% (w/w) for thickener and filter sizing.