Mud, Mud, Glorious Mud… or is it?

However, a bi-product from the bauxite refining process is now emerging as a cargo for shipment. This product is commonly referred to as red mud.

What is it good for?

Red mud is usually a low-quality product but there is reported demand from regions such as the Middle East and China. There are a number of laboratory and field trials of processes to extract components such as iron from this red mud.

It is understood that none of these have progressed to full industrial scale yet. This work is more advanced in China, where the cost of iron ore and new environmental constraints mean there is a drive for recovery.

It is generally stored in large and highly toxic tailings dams due to its limited uses and concerns over safe shipment.

Dangers to ship and crew

The carriage of red mud cargo is a high-risk operation. It is known to be a highly variable cargo, and often very fine.  Furthermore, as well as being a potentially usable product it can also be carried as a waste product.

Red mud commonly contains a large proportion of fine particles less than 1mm in size and generally has a very high relative moisture content. Once on board, even an apparently stable cargo has been known to break down very quickly once the cargo is repeatedly stressed by exposure to wave energy. This is of particular concern for smaller bulk carriers on longer voyages.

Some versions of the cargo can resemble slurry, which results from a high concentration of super fine particles know as ‘slimes’.

Experts have reported of vessels being unable to leave the anchorage directly after loading because of this cargo’s adverse effect on the vessel’s stability.

Once on board, should a problem occur then de-watering operations may be the only action possible to stabilise the cargo, which can prove costly and result in significant delays.

The cargo is highly caustic (high pH) making it corrosive to the vessel’s steel hull as well as being hazardous to human health through contact with the skin.

How to carry?

Shipowners should be highly cautious of accepting a shipment of red mud – it should be considered a high-risk operation.

Red mud does not have a schedule in the IMSBC code and North is not aware of any plans for it to be included in the future, most likely due to the high variability of the cargo.

Therefore, red mud falls under section 1.3 of the IMSBC Code and should be carried accordingly.

In any event we recommend you seek expert advice prior to accepting a cargo of red mud.

AKA – Also Known As!

Shipowners and masters should be aware that red mud can be declared under numerous different names. Some of the primary brand names are:

• ARR (alumina refinery residues)
• BRR (bauxite refinery residue)
• Bauxsol
• NRM (neutralised red mud)
• NARR (neutralised alumina refinery residues)
• UNRM (un-neutralised red mud)
• CNRM (CO₂ neutralised red mud)

Regardless of any branding, the risks remain the same.

With thanks to Roxburgh Group Limited for their assistance with this article.