Evaluación de la lixiviación y el comportamiento térmico en la calcinación de lodos generados durante tratamiento de efluentes de anodizado de piezas de aluminio.

Abstract

In this work, alternatives to reuse aluminum anode sludge (LA) produced in the anodizing industry for surface treatment in the production of aluminum profiles are presented. A complete characterization of the residue (LA) is carried out, including physical and chemical parameters. Hydrometallurgical and pyrometallurgical processes were evaluated for the recovery of sodium aluminate and refractory materials, respectively. For the hydrometallurgical process, leaching is carried out. varying the concentration of the leaching agent (NaOH, 1 M, 1,5 M, 2 M, y 2,5 M) and the percentage of solids (10%, 20% y 30%). It was determined that at 10% solids and 2M NaOH, a recovery of 93.7% of aluminum as sodium aluminate was obtained. While, by the pyrometallurgical process, the LA were calcined at different temperatures (200, 300, 400, 600, 800, 1000, 1200, 1400 and 1600 °C). In addition, the granulometry was varied (-3 +1 mm, -1000 +400 μm, -400 +200 μm) to obtain refractory materials. The optimal result for pyrometallurgical was at 1600°C, which presented close to 70% corundum (α-Al2O3) and 30% diaoyudaoite (NaAl11O17).