The Kombat copper project is located in the Grootfontein district in Namibia.
The project is expected to produce 4,000 tonnes (t) of copper concentrate in 2022. Image courtesy of Jonathan Zander (Digon3).
The probable reserves of the Kombat copper project are 0.77Mt. Image courtesy of Minxcon.

Kombat copper project is an open-pit mine located in the Grootfontein district in Namibia. Trigon Metals is the owner and developer of the copper project that resumed production in October 2021 after 14 years of closure.

The Kombat copper mine was under production between 1962 and 2008, until the mining operations were closed due to low copper prices and underground flooding. The mine had produced 12.46 million tonnes (Mt) of copper during that period.

Trigon Metals came to own the mine in 2012 through the acquisition of Manila Investments, which had 100% ownership of the mine. Manila Investments now operates as a subsidiary of Trigon Metals.

A feasibility study to restart the project was completed in April 2018 and the report was released in June 2018. Trigon received the environmental clearance certificate (ECC) from the Namibian Government to restart the copper mining operations at Kombat in July 2021.

Copper production from the Kombat mine

Trigon Metals plans to ramp up production from the Kombat open-pit mine to 4,000 tonnes (t) of copper concentrate a year in 2022.

The production is further planned to be increased to 14,500t of copper concentrate a year in 2024, with the recovery of higher-grade underground ore resources and upgrades to the existing crushing and milling infrastructure at the site.

Kombat copper project location, geology and mineralisation

The Kombat copper project is situated north of the Kombat mining town in the Grootfontein district in Otjozondjupa region of Namibia. The project site lies approximately 37km to the east of the Otavi town and 45km to the west of the Grootfontein city.

The project’s mining and prospecting licence areas cover more than 7,500ha in the Otavi Mountainlands of Namibia.

The ore deposits at the mine are hosted by dolostone of the Huttenberg formation, which is overlain by the Mulden Group. The Tschudi and Kombat formations are part of the Mulden Group.

The Tschudi formation comprises basal conglomerate, a feldspathic arenite containing intraformational breccias and greywacke. The Kombat formation is covered by the Tschudi formation and is made of a sequence of siltstone, shale and sandstone. The formation was transformed to form slate at some areas of the mine.

Ore reserves at Kombat copper project

The probable ore reserves at the Kombat open pit mine were estimated to be 0.77Mt graded at 1.3% and containing 9,985t of copper as of April 2018.

The indicated and inferred mineral resources of the project as of August 2021 stood at 12.22Mt grading 1.94% Cu and 1.91Mt grading 2.81% Cu, respectively.

The indicated mineral resources were estimated to be 5.28Mt grading 2.79% Cu, whereas the underground indicated resources were estimated to be 6.93Mt grading 2.83% Cu.

Mining and ore processing at Kombat copper project

The conventional open-pit mining method comprising blasting and excavation is used at the Kombat copper project’s open-pit operation. The mining equipment includes excavators, dump trucks, haul trucks, and dozers. Underground mining is planned to be started in 2024.

The excavated blasted material is loaded onto artificial dump trucks (ADTs) and transported to the processing plant, which has a capacity of 35 kilo tonnes per month (ktpm). The run-of-the-mine (ROM) material is stockpiled and fed into the processing plant through front-end loaders. It will be crushed and then screened at the secondary crushing circuit.

The screened ore is sent to the milling circuit where it will undergo regrinding. The final slurry will be sent to the flotation circuit that comprises scavengers, roughers, cleaners, and recleaner circuits to produce copper concentrate with a grade of 22% Cu. The final flotation concentrate will be sent to two 40ft thickeners, which will act as a buffer for filter press.

The concentrate will be filtered at the filter press and the resultant filter cake will be discharged into trucks and transported to end customers.

Financing and off-take agreements

Trigon Metals and its subsidiary, Manila Investments, signed an agreement with an undisclosed international trading house in October 2017 for the off-take of 100% of production from the Kombat copper project.

The agreement also included the provision of a financing facility of up to $7.7m (£5.83m) to be used towards restarting the open pit operations.

Infrastructure details

The Kombat East and Central operation of the Kombat copper project can be accessed via the B8 regional paved road, through an exclusive access road.

The 35ktpm plant requires 3.2MW of power, which is sourced from the NamPower grid. Water required for the project is sourced from the No.1 Shaft at the Kombat complex.

Power supply agreement

Trigon Metals signed a power supply agreement for the Kombat mine restart with Central North Regional Electricity Distributor (CENORED), a regional electricity distribution company in Namibia, in August 2021.

Contractors involved in the Namibian copper project

Tulela Mining & Construction, a company based in Namibia, was appointed as the open-pit mining contractor for the Kombat copper project in August 2021.

The technical report for the project was prepared by Minxcon, an advisory company specialising in geological modelling, mineral resource estimation and financial evaluation.

Yantai Xinhai Industry & Trade (formerly Xinhai Mining Engineering), a company based in China, supplied various equipment, including new flotation cells, for the restart of the Kombat processing plant.

Trigon had signed a memorandum of understanding (MoU) with Shandong Xinhai Mining Technology & Equipment in March 2019, under which the latter was to invest in the former and in exchange would serve as the engineering procurement and construction (EPC) contractor for the Kombat copper mine restart.