Study on the Effect of Humic Acid on Foam Formation in Bayer Process Decomposition Tanks

Foam formation within decomposition tanks poses a significant issue affecting alumina production, drawing increasing attention in industrial processes. This study explores the influence of humic acid (HA) on foam formation in decomposition tanks, considering variables such as HA concentration, decomposition time, solid content, and high-temperature treatment time of HA. The findings reveal that the foaming capacity of sodium aluminate solutions containing HA increases with HA concentration. Both the foaming volume (FV) and foam stability decreases with extended decomposition time. The FV of the solution initially rises and then decrease as solid content increases. Following high-temperature degradation at 260 °C, the foaming performance (FP) of HA is reduced. Analyses using FT-IR, surface tension, and particle size measurements indicate that HA molecules modify the properties of sodium aluminate solutions and particle surfaces, resulting in foam generation within decomposition tanks. The study provides a theoretical analysis of the mechanisms underlying foam formation and decay in sodium aluminate solutions containing HA. This research provides theoretical support for foam eliminating in alumina production, facilitating the development of HA removal processes and foam control technologies. Graphical