I think you guys are parsing that sentence as “relatively new cargo, bauxite”. At the top of the article they define “solid bulk cargo” as a shipping jargon term, for a fine granulated material. This seems like a dangerous misnomer to me...

I’m assuming that means that historically, the refiner owner the pulverizing equipment and shipped in bauxite rock or gravel as raw material. When you hear of liquefaction in terms of earthquake damage, they are always talking about saturation of fine materials. Saturated gravel doesn’t behave as badly as saturated sand or clay.

I assumed the word new in that usage referred to it being newly taken from the ground, thus having more unpredictable moisture content. Bauxite is basically just dirt.

This video talks of shipping bauxite from South America to the US in 1941: https://www.youtube.com/watch?v=EK4dEEoKNiE

Similarly, Wikipedia claims bulk carriers have been around since 1850: https://en.wikipedia.org/wiki/Bulk_carrier

Doesn't sound all that new.

Not over long distances. It's still ore, after all. Not something you want to ship further than you have to.