Studies confirm Malingunde as large high-grade graphite resource

By Deborah Manda

Studies have confirmed the Malingunde graphite deposit in Eastern Lilongwe rural as the world’s largest reported saprolite-hosted flake graphite resource, says ASX listed Sovereign Metals, which holds the mineral tenement for the deposit.

“The recently reported maiden JORC Mineral Resource Estimate for the Malingunde Project confirms its global significance and provides the basis for a potentially low capital cost and very low      operating cost natural flake graphite operation,” says Sovereign Metals Managing Director Julian Stephens in the company’s quarterly report ending March 2017.

Stephens explains that total saprolite Mineral Resource Estimate (MRE) for Malingunde is at 28.8Mt at 7.1% TGC and includes high grade saprolite component of 8.9Mt at 9.9% TCG.

He says the high-grade component is to provide the focus for the Scoping Study which is well advanced and due for mid-late May completion.

Stephens says the studies have unveiled beneficial features that show that Malingunde has the potential to be a world class asset which will have low capital requirements, low operating costs and high revenues per ton of concentrates.

“Very soft saprolite is within 30m of the surface and will be free-digging with very low strip ratio, which should equate to much lower life-of mine mining cost. The soft saprolite material does not require primary crushing or grinding which will result in substantially reduced processing costs     compared to hard rock deposits,” he says.

Stephens also says the studies have   indicated metallurgy improvements as continued flotation test work on Malingunde saprolite has achieved exceptional flake size distribution and very high purity concentrates.

Saprolite-hosted graphite deposits are sought after as they generally have lower capex requirement and low operating costs compared to hard rock graphite mines.

Results from expandability test-work conducted on Malingunde flake graphite concentrates by a renowned German industrial minerals laboratory show world class expandability characteristics across a number of different graphite concentrate size fractions.

The concentrates are free of quartz grains and hence represent a good base material for the preparation of expandable graphite and production of graphite foils.

The report also adds that proximity of the deposit to Malawi’s capital means access to infrastructure, rail, water, power and labour is also a benefit to sovereign Metals.

Stephens says the excellent results enhance Sovereign’s ability to target entry into the existing, traditional markets for its flake graphite products as the base case to underpin Malingunde development.

Expanded flake graphite has a wide variety of uses in fuel cell, seals and gaskets, fire retardants, flow batteries, thermal management for consumer electronics and many more other products.

Sovereign Metals Limited explored Malingunde area in 2015 and 2016, resulting in the discovery and definition of the world’s largest reported saprolite-hosted graphite resource.

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This piece was initially published in Malawi’s Mining & Trade Review Issue Number 50 (June 2017).

The full edition is available for download here. This monthly publication is edited by Marcel Chimwala.