Bauxite is a major dry bulk cargo, with global seaborne trade of approximately 130 to 150 million tonnes per year, principally moving from Guinea, Australia, Indonesia, and Brazil to alumina refineries in China, the Middle East, Europe, and North America. Bauxite is the principal feedstock for alumina production, which is then smelted to aluminium metal. The cargo is regulated under the International Maritime Solid Bulk Cargoes Code (IMSBC) and was the subject of significant code amendments following the loss of the bulk carrier MV Bulk Jupiter off the coast of Vietnam in January 2015 with the loss of 18 lives.
IMSBC schedule structure
The IMSBC Code originally classified bauxite as a Group C cargo (not liquefiable, no chemical hazard), reflecting its long history as a dense lump material handled without incident. Following the Bulk Jupiter casualty, in which Malaysian bauxite from the state of Pahang was implicated in a sudden cargo shift consistent with liquefaction, the IMSBC Code was amended to introduce a separate “Bauxite Fines” Group A entry alongside the original Group C entry:
- Bauxite (Group C): Coarse lump material with low fines content. Not liquefiable. Standard bulk handling.
- Bauxite Fines (Group A): Material with at least 30 per cent fines below 1 millimetre or at least 40 per cent below 2.5 millimetres and a moisture content potentially above transportable moisture limit. Liquefiable. Subject to TML and MC testing before loading.
The shipper must determine the particle size distribution and moisture characteristics of each consignment and assign the correct group classification.
Bulk Jupiter loss and code response
The Bulk Jupiter, a 56,000 deadweight tonne supramax bulk carrier, sank in the South China Sea on 2 January 2015 shortly after departure from Kuantan, Malaysia, with a cargo of approximately 46,400 tonnes of bauxite bound for China. Of the 19 crew aboard, only one survived. The Bahamas Maritime Authority investigation concluded that liquefaction of fine bauxite was a probable cause, observing that the cargo had been loaded during a period of intense rainfall, that pre-loading sampling and TML certification had been inadequate, and that the cargo’s particle size distribution included a high proportion of fines.
The IMO MSC 96 in May 2016 issued a circular advising flag states and operators to treat all bauxite as potentially liquefiable until a competent authority had certified otherwise, and the Bauxite Fines Group A schedule was formally added to the IMSBC Code in subsequent amendments. The Global Bauxite Working Group (GBWG), an industry-led consortium including major bauxite shippers, miners, and class societies, conducted research on bauxite liquefaction mechanisms and contributed to the new schedule’s TML test methodology.
Liquefaction mechanism
Bauxite fines liquefaction follows the same general mechanism as iron ore fines liquefaction: ship motion compacts the cargo, pore-water pressure rises, inter-particle friction is overcome, and the cargo behaves as a viscous liquid. Bauxite has somewhat different rheology than iron ore due to the platey kaolinite mineral content typical of tropical lateritic bauxite ores, and a phenomenon described as “dynamic separation” — partial liquefaction at the surface with formation of a free water layer that can shift suddenly — has been documented for bauxite cargoes specifically. The Proctor-Fagerberg test was modified for bauxite fines to better characterise this dynamic separation behaviour.
Pre-loading testing
The IMSBC Code requires shippers of Group A bauxite fines to provide certified TML and MC documentation no more than seven days old at loading. Sampling is performed in accordance with the IMSBC Code Section 4 protocol with a representative sample drawn from the consignment in storage. Laboratory analysis applies the modified Proctor-Fagerberg test for bauxite fines and reports the TML, the MC, and the recommended maximum loading moisture (typically 90 per cent of TML).
The master is entitled to refuse loading if the certificate is missing, expired, or appears inconsistent with cargo condition. A “can test” can be performed shipside as a rapid screening procedure but is not a substitute for laboratory certification.
Major exporters and routes
Bauxite seaborne trade is dominated by:
- Guinea: by far the largest exporter, with shipments through the ports of Kamsar, Conakry, Boké, and Boffa. Guinean bauxite is generally well-characterised and shipped under controlled-moisture protocols. Annual exports exceed 90 million tonnes.
- Australia: long-established exporter from Weipa, Queensland (Rio Tinto) and Gove, Northern Territory. Australian bauxite is generally low-moisture and shipped as Group C lump material.
- Indonesia: significant exporter to China and other Asian markets. Some Indonesian bauxite has been associated with elevated liquefaction risk and falls into the Group A fines category.
- Brazil: exporter from Trombetas (Mineração Rio do Norte) and Juruti (Alcoa). Brazilian bauxite is variable in moisture and particle size; some shipments are Group A and others Group C.
- Malaysia: a smaller but historically problematic exporter following the Bulk Jupiter loss. Malaysian bauxite mining has been more closely controlled since 2016.
Cargo handling onboard
Bauxite is loaded by shore conveyor and shiploader. Trimming with bulldozers may be required to flatten the surface for hatch closure. Bilge wells should be checked and cleared before loading; some bauxite cargoes release significant pore water during the voyage that accumulates in the bilges, and this water requires periodic pumping out subject to safety procedures.
The cargo discharges by grab-fitted shore cranes at receiving ports including Qingdao, Yingkou, Bayuquan, Gladstone, and various Middle Eastern alumina refinery ports. Bauxite is significantly dustier than iron ore and dust suppression measures are increasingly required at both load and discharge ports under local environmental regulations.