Kinetic and Thermodynamic Study of Aluminum Recovery from the Aluminum Smelter Baghouse Dust

Abstract

The recovery and utilization of metals from wastes are important for saving metal resources, as well as for protecting the environment. There are various types of solid wastes that have different origins and forms. Elemental and mineralogical composition of the wastes depends on the industry where they come from; therefore, the recovery processes for these materials are widely different. In general, the recovery of metals from ores and/or concentrates is carried out by extractive metallurgy methods comprising pyrometallurgy, hydrometallurgy, and electrometallurgy. In this research, sodium carbonate and sodium hydroxide leachings with different experimental conditions are tested for the aluminum dissolution. Also, a kinetic and thermodynamic study of sodium hydroxide leaching of the aluminum smelter baghouse dust is conducted. It is determined that when the solids content is 10 g/L, the overall reaction rate is controlled by pore diffusion and the activation energy is calculated to be about 4.8 kcal/mol. At temperatures below 100 °C, the stable form of the recovered compound after leaching is sodium aluminate.