Key data
| Stowage factor | 0.72–0.83 m³/t (typical 0.78)25.4–29.3 ft³/t (typical 27.5) |
|---|---|
| Form | Bulk |
| IMSBC group | A and C |
| Angle of repose | ~30-35 |
| BCSN | BAUXITE |
ft³/t values are per metric tonne (1 m³/t ≈ 35.31 ft³/t). Stowage factors are indicative — see note below.
Description
Bauxite is the main commercial source of aluminium and moves in very large volumes from tropical producers to refineries. As a dense ore it loads down to the marks well before the holds fill, behaving as a deadweight cargo. For many years it was regarded as a safe, inert material, and coarse, dry bauxite still is – but the trade's safety understanding changed after a fatal casualty involving a fine, moist cargo.
Stowage & loading
Coarse bauxite is loaded by conveyor or grab and trimmed level, sitting low in the hold. The decisive question at the load port is the nature of the specific parcel: its particle-size distribution and moisture condition determine whether it is the inert material or a finer product that can behave very differently at sea, so the declaration and grading are checked rather than assumed from the name alone.
Hazards & handling
Coarse bauxite is largely inert, but fine bauxite with a high proportion of small particles can take up and hold water and, under a voyage's motion, can liquefy or form a free slurry surface that threatens stability. The loss of a bulk carrier and most of her crew in 2015 led to a dedicated schedule for fine bauxite as a cargo that may liquefy. The practical hazard, then, is misjudging a fine, wet parcel as ordinary inert bauxite.
Carriage & discharge
An inert coarse parcel is an undemanding carriage, monitored for water in the holds and bilges. A fine parcel accepted within safe moisture limits is watched for any sign of shifting or free water exactly as a liquefiable cargo would be. Discharge is by grab or unloader at refinery terminals, with holds washed down on completion; residual fine material can be slippery and is cleared with care.
Key hazards
- Liquefaction of fine, wet bauxite, producing a free surface and loss of stability (basis of the separate Group A bauxite-fines schedule)
- Misjudging a fine, moist parcel as ordinary inert Group C bauxite
- High point loading on the tank top from a dense, low stow
Loading precautions
- Check the particle-size distribution and moisture of the actual parcel; do not assume inert behaviour from the name
- Where the cargo is fine and potentially wet, treat it as a Group A liquefiable cargo with moisture and TML certification
- Monitor holds and bilges for free water throughout loading and the voyage
Stowage factors are indicative and vary with grade, origin, moisture and packing. Always verify against the shipper's cargo declaration and the applicable IMSBC Code schedule before fixing or loading. This is general information, not professional or safety advice.