Effect of synthetic and natural polymers on reducing bauxite residue dust pollution.

Dust emission from the bauxite residue drying areas is of great concern for its serious environmental and health impacts. The application of polymer stabilizers is a promising approach to mitigate such issues. However, limited studies have been done on their application on red sand and the investigation of the effect of polymers on penetration resistance, which is a key mechanical property closely related to the dust control performance. Stabilizers reduce the dust emission potential by forming a crust on the surface of treated material. This paper investigates the relationship of crust properties and dust control performance by applying synthetic (polyacrylamide) and natural (xanthan gum and guar gum) polymers. Results illustrated that the water retention property of treated sand is greatly improved after the application of stabilizers. The thickness of the formed crust decreases with stabilizer concentration. Results from wind tunnel simulation illustrated that the polymer stabilizer offers nearly 8 times longer protective period than water when used as a stabilizing agent. Cationic PAM performed the best, and cationic guar gum outperformed anionic xanthan gum. The penetration resistance is proved in this study to be a primary index for predicting dust control performance of polymer stabilizers.