Improved bauxite residue dealkalization by combination of aerated washing and electrodialysis.

Bauxite residue, a major by-product of the alumina-producing Bayer process, is a serious environmental pollutant due to its high alkalinity. Here, we reported an operation system designed in our laboratory that included washing and electrodialysis dealkalization systems with aeration pipes. Washing with aeration releases a substantial amount of free alkali and attached alkali into water and increases the dealkalization efficiency.

Study on dealkalization and settling performance of red mud.

At present, the dealkalization and comprehensive utilization of red mud is a worldwide problem. Studies on the settling performance and phase transformation of red mud by HCl, CaO, and HO leaching are limited. In this study, the characteristics of red mud were systematically analyzed.