Treatment of Mine Wastes with Transformed Red Muds (TRM) and Other Iron Compounds: Leaching Column Tests

Leaching column experiments were conducted on sulfide-bearing mine waste material to evaluate the efficacy of transformed red mud (TRM) derived from bauxite refining residue, zero-valent iron, and synthetic iron (III) hydroxides in reducing contaminant mobility. Wastes were placed in columns together with sorbents/reagents in three different setups: as a blended amendment (mixing method), as a bed at the bottom of the column (filtration method), or as a combination of the two previous methods. Results showed that filtration methods are the most effective, whilst the use of sorbents/reagents as amendments leads to unsatisfactory results, because of selective removal.