Malingunde graphite project is a soft saprolite-hosted graphite project being developed in Malawi. Sovereign Metals (SVM) is developing the project, which is believed to contain the best flake graphite in the world.
Scoping study of the project, with main focus on maiden resources, was completed in 2017, while pre-feasibility study (PFS) was completed in November 2018. Definitive feasibility study (DFS) is currently underway.
With an estimated capital cost of $49m, the project is expected to produce approximately 52,000t of concentrate a year through its initial mine life of 16 years.
Malingunde graphite project geology and mineralization
The Malingunde graphite deposit is located on the Lilongwe Plain above paragneiss rocks, which host graphitic units on a large-scale.
The deposit is known to contain the soft saprolite graphite resource in the world and believed to have formed through tropical weathering of primary graphitic gneisses. Most of the silicate minerals found at the deposit, except quartz, were altered to clay resulting in the formation of a soft, friable saprolite horizon with an average vertical thickness of 25m.
Graphite mineralization at Malingunde is mostly located near surface and comprises ocoarse and jumbo flake graphite. It has a strike length of more than 3.4km and an average cumulative across strike width of 120m.
Malingunde graphite project reserves
The Malingunde graphite project is expected to contain 9.5 million tonnes (Mt) of ore, including 3.1Mt of proven and 6.4Mt of probable reserves. The ore is expected to be graded at 9.5% total graphite content (TGC).
Mining and ore processing
Conventional open-pit mining, involving truck and shovel, will be applied at the Malingunde mine. The project will be contracted for the initial seven years, followed by owner-operator model from the eight year.
Due to its complex nature, the high-quality graphite ore will be directly forwarded to the processing plant without any crushing, grinding, and chemical/heat purification. The run-of-mine (ROM) ore will be sent to a 600,000tpa processing plant by using a front-end-loader (FEL).
Ore will be sized in a mineral sizer for primary size reduction and forwarded to a scrubber charged with steel media. Discharge slurry from the scrubber will pass through a 10mm screen with the oversize directed to a small pebble crusher. The undersize material will be pumped to rougher flotation section for processing.
The flotation concentrate will undergo polishing, regrinding, and cleaner flotation stages with the resulting concentrate split into coarse and fine fractions at 180µm. The final concentrate fractions will be combined, thickened, and fed to a filter before being dewatered.
A diesel-fired rotary dryer will dry the filtered concentrate, which will then be screened and packed in bags for dispatch and sale. It will be trucked by road to the Kanengo rail head in Lilongwe before being transported to the deep water port of Nacala, Mozambique.
Graphite concentrates transport from Malingunde
SVM has engaged Central East African Railways (CEAR) for the transportation of graphite concentrate from Malingunde, under a transport logistics memorandum of understanding (MoU).
CEAR, a consortium between Vale and Mitsui, has agreed to transport the material by rail and will also provide port access and handling services, as part of the MoU. The consortium will, further, be responsible for the supply and maintenance of infrastructure, equipment, and personnel required to transport 100,000tpa of concentrates for up to 20 years.
Sovereign Metals has raised gross proceeds of $6.5m through an issue of 59.1 million shares, priced at $0.11 a share, for developing the Malingunde graphite project.
Access to the project is from the M1 highway, through a bitumen road, which comprises a 10km all-weather gravel road.
Power supply for the project will be sourced from Malawi Electrical Supply Corporation’s (ESCOM) 132/11kV substation near Bunda. A transmission line will be constructed to link the project to the sub-station, which is expected to come online by 2024.
SVM prepared the PFS of Malingunde with support from independent consultants such as Minnovo, CSA Global, SGS Canada, Orelogy Mining Consultants, Peter O’Bryan and Associates, SLR Consulting, Dhamana Consulting, AECOM, and Grindrod Rail Consultancy Services.
ALS Global was appointed to conduct studies related to processing, as part of the PFS.