Nyanga Manganese Operation

Overview

Nyanga is a plateau-hosted manganese deposit in Gabon’s Haut-Ogooué Province, in a district that has produced manganese since the 1960s. Quintel acquired the permit in 2016 from a vendor that had run out of capital mid-construction, completed the plant on a revised design and shipped first ore in 2018.

The deposit is exceptional in two respects: grade and geometry. Run-of-mine ore averages 43% manganese — among the highest of any operating mine outside the Kalahari field — and the mineralisation is a flat-lying blanket beneath thin overburden, giving a life-of-mine strip ratio of 1.4:1. Together those make Nyanga a genuinely low-cost operation despite its remote location.

Production in FY2025 was 0.74 Mt of saleable ore, 39% of group manganese output. Product is trucked 34 kilometres on a dedicated haul road to a rail loadout and then railed 620 kilometres on the Trans-Gabon line to the deepwater port of Owendo.

Geology and resource

The manganese occurs as a supergene-enriched blanket developed by lateritic weathering over a Palaeoproterozoic protore of the Francevillian Basin. Enrichment has produced pisolitic and massive ore in a layer averaging 5.8 metres thick beneath 4 to 9 metres of ferruginous overburden.

Because the enrichment profile is weathering-controlled, the resource is defined by closely spaced shallow drilling — a 50 m by 50 m pattern on auger and reverse circulation holes — rather than by deep diamond drilling. Grade continuity is excellent laterally and poor vertically, which drives a grade-control regime based on bench-by-bench sampling ahead of the excavator.

Mineral resources and ore reserves

Mining, processing and logistics

Mining is free-dig over most of the deposit, using hydraulic excavators and 40-tonne articulated trucks with no drilling or blasting required in the ore zone. Overburden is stripped and stockpiled for immediate progressive rehabilitation behind the advancing face, so the disturbed footprint at any time is limited to approximately 42 hectares.

Processing is deliberately simple: scrubbing, screening and washing to remove clay and fine silica, with no chemical treatment and no tailings dam. Wash water is recycled through settling ponds at a 91% recovery rate and the fine residue is dewatered and returned to the mined-out void.

Rail is the operation’s critical dependency. Quintel holds a take-or-pay slot agreement on the Trans-Gabon line and maintains its own wagon fleet with a maintenance depot at the loadout. Rail reliability reached 96% in FY2025, up from 78% in the first full year of operation, mainly through moving to fixed weekly slots and pre-loading rakes.

Operating performance

Forest, water and biodiversity

Gabon is 88% forested and has made the protection of that forest a defining element of national policy. An operation that clears trees in Gabon is held to a standard that would be unusual elsewhere, and Quintel accepted that condition when it acquired the permit.

Nyanga operates under a forest management plan agreed in 2023 with the national parks agency and the ministry responsible for forests. Clearing is limited to the advancing mining strip; 1.9 hectares are rehabilitated for every 2.0 hectares cleared, with a target of net gain by 2032. All rehabilitation uses seedlings grown in an on-site nursery from locally collected seed of 34 native species.

A camera-trap monitoring programme run jointly with a Gabonese research institute has recorded forest elephant, mandrill and golden cat movements across the concession since 2019. Haul road crossings were relocated twice on the basis of that data, and night haulage is suspended during the two seasonal elephant movement windows.

People and contribution

Nyanga employs 610 people, 93% of them Gabonese nationals and 47% recruited from Haut-Ogooué Province. Because the region has limited technical training capacity, the operation runs a two-year apprenticeship in partnership with a national technical institute; 128 apprentices have completed the programme and 104 remain employed in the group.

The operation paid US$41 million in taxes and royalties in FY2025 and contributed US$3.1 million to community programmes, prioritised by village councils through an annual planning process. Investment has concentrated on electrification of four villages along the haul road, a health post staffed by a permanent nurse, and agricultural extension work aimed at replacing income from bushmeat hunting.

Outlook

Guidance for FY2026 is 0.75–0.82 Mt. A third wash module, approved in 2025 at a cost of US$46 million, will lift capacity to 1.1 Mtpa from 2027 subject to a matching increase in the rail slot allocation, which is under negotiation.

A scoping study is under way into a manganese sinter plant at Owendo, which would raise the value of exported product and reduce shipped tonnage per unit of contained manganese. A decision is not expected before 2028.