AUSTRALIA. The ?super-thickener? at the Pinjarra Alumina Refinery This is one of the world's biggest industrial residue de-watering plants, which thickens bauxite residue almost to the consistency of toothpaste. From there, the residue or "red mud" is spread on drying beds where solar energy dries it to a point where it can become load-bearing. Alcoa has a long history of research into alternative uses for red mud, aimed at turning the stored residue into a useful resource.