Producer
South32 / GEMCO (Manganese Ore)
South32 Limited (ASX: S32, HQ Perth); operates GEMCO (Groote Eylandt Mining Company, 60% South32 / 40% Anglo American) — Australia's largest manganese ore mine on Groote Eylandt, Northern Territory. GEMCO produces >15% of global manganese ore supply. CRITICAL INCIDENT: Cyclone Megan caused significant infrastructure damage in March 2024, halting operations; recovery targeting 1M wet tonnes FY25 rising to 3.2M mwt FY26. GEMCO scheduled for closure in 2029 — Australia's primary manganese source will be eliminated. South32 also operates South Africa Manganese (Hotazel Manganese Mines, Northern Cape, Kalahari Field).
0
Inputs supplied
0
Goods downstream
1
Facilities
0
Stories
What else they do
Business segments
The company's full revenue map — where this supply-chain role fits within their broader business.
GEMCO Manganese (Groote Eylandt, Australia)
55%South Africa Manganese (Hotazel/Kalahari)
30%Aluminium, Coal & Other Metals
15%
Intelligence
What's known
Sourced claims about this company's role in supply chains — chokepoints, concentration, incidents, dual-use connections.
Chokepoint2024
GEMCO's March 2024 Cyclone Megan damage and its scheduled 2029 closure create a dual supply chain disruption timeline for manganese consumers across alkaline battery makers (EMD cathode), steel producers (ferromanganese alloy), and EV battery cathode manufacturers (manganese sulfate for NMC and LMO batteries). These three supply chains share GEMCO's Groote Eylandt production as a significant non-Chinese manganese source. The 2024 cyclone damage demonstrated acute disruption risk; the 2029 scheduled closure creates a structural supply gap. Battery makers sourcing non-Chinese EMD through Vibrantz/Erachem (which uses non-Chinese manganese ore) and steel producers using Australian ferromanganese would need to transition to South African (Kalahari field) or Gabonese manganese sources by 2029. A climate event (cyclone in the Gulf of Carpentaria) that disrupts an alkaline battery cathode supply chain, a steel alloy supply chain, and an EV battery material supply chain simultaneously -- with the warning that the disruption becomes permanent in 2029.
South32 Limited ↗Origin2023
GEMCO (Groote Eylandt Mining Company) was established in 1963 on Groote Eylandt -- a large island in the Gulf of Carpentaria, Northern Territory, Australia, which is also home to the Warnindhilyagwa Aboriginal people who have occupied the island for at least 30,000 years. The manganese deposit on Groote Eylandt is one of the highest-grade known manganese ore bodies globally, with ore grades averaging 45-48% Mn. BHP developed the mine initially; it is now 60% South32 (spun off from BHP in 2015) and 40% Anglo American. GEMCO has been operating continuously since 1966. In March 2024, Cyclone Megan struck Groote Eylandt, causing significant infrastructure damage to GEMCO's loading and processing facilities -- halting production and cutting off what represented more than 15% of global manganese ore supply in one weather event. The mine is scheduled for closure in 2029 as the ore body approaches exhaustion, which will permanently remove Australia's primary manganese ore source from global supply and require the EMD and ferromanganese industry to source from South African and Gabonese deposits.
South32 Limited ↗