Manganese ore is a major dry bulk cargo, with global seaborne trade of approximately 25 to 35 million tonnes per year. The cargo serves principally as a feedstock for steelmaking, where manganese is a critical alloying element for strength, hardness, and grain refinement, and for ferromanganese and silicomanganese alloy production. The IMSBC Code regulates manganese ore shipments under separate schedule entries reflecting particle size and moisture characteristics, mirroring the structure of the iron ore code.
Schedule structure
The IMSBC Code includes the following manganese ore-related schedule entries:
- Manganese ore: lump and pellet manganese ore. Group C (not liquefiable, no chemical hazard) for the coarse-grade material.
- Manganese ore fines: fine-particle manganese ore with elevated moisture content. Group A (liquefiable), subject to TML and MC certification.
Most modern seaborne manganese ore trade is the lump and pellet grade handled as Group C. Some regional trade in fines and concentrate falls into the Group A category.
Cargo properties
Manganese ore is supplied as crushed lump material with particle sizes typically 5 to 50 millimetres for the lump grade and below 5 millimetres for fines. Bulk density is approximately 2.5 to 3.0 tonnes per cubic metre, slightly less than iron ore. Stowage factor is approximately 0.35 to 0.42 cubic metres per tonne.
The cargo is non-toxic, non-flammable, and non-self-heating. The principal handling concerns are dust generation (similar to iron ore), liquefaction risk for the fines variant, and structural loading on the cargo hold tank top and double bottom from the high cargo density.
Major exporters
Manganese ore seaborne trade flows include:
- South Africa: by far the largest exporter, with Hotazel, Mamatwan, and Wessels mines in the Kalahari Manganese Field providing approximately 35 to 40 per cent of global supply. Exports flow through Port Elizabeth, Saldanha, and Coega.
- Gabon: second-largest exporter, principally from the Comilog/Eramet mine at Moanda. Exports flow through Owendo (Libreville) on the Atlantic coast.
- Australia: exports from Groote Eylandt (BHP) and Bootu Creek (OM Holdings) in the Northern Territory.
- Brazil: exports from Vale and Buritirama mining operations.
- Ghana: exports from the Nsuta mine through the port of Takoradi.
- Burkina Faso: emerging exporter through Ivorian and Ghanaian ports.
China is the dominant single importer, accounting for approximately 60 to 70 per cent of global manganese ore seaborne trade, supplying the world’s largest steel and manganese alloy industry.
Loading and discharge
Loading is by shore conveyor and shiploader at major export terminals. Loading rates of 2,000 to 5,000 tonnes per hour are typical. Hold preparation requires standard cleanliness and bilge clearance.
Discharge is by grab-fitted shore cranes at receiving steelmaker and ferroalloy plant terminals.