In this study, a new red mud/fly ash composite material (RFCM) for phosphate removal was prepared by granulation and activation methods, using bauxite residue (red mud, RM) as the main raw material, adding with some fly ash and a few adhesives. The effects of different types of RM and adhesives on RFCM for phosphate removal were discussed. It was found that RFCM prepared from sintering red mud and cement waste performed better on phosphate removal than that prepared from Bayer red mud and common industrial adhesives. After calcination activated at appropriate temperature around 800–900℃, the specific surface area of RFCM increased, and new substances with hydroxyl (–OH) appeared on the surface of RFCM, which were the functional groups for phosphate removal. Mechanism of RFCM for phosphate removal was speculated as a combination of physical adsorption, chemical adsorption and chemical precipitation, which mainly depended on ligand exchange and chemical reaction. This research will provide a potential application of bauxite residue in environmental remediation.

本研究以铝矾土残渣（赤泥，RM）为主要原料，加入一些粉煤灰和少量粘合剂。讨论了不同类型的 RM 和粘合剂对 RFCM 去除磷酸盐的影响。研究发现，由烧结赤泥和水泥废料制备的 RFCM 对磷酸盐的去除效果优于由拜耳赤泥和普通工业粘合剂制备的 RFCM。在800~900℃左右的适当温度下煅烧活化后，RFCM的比表面积增加，RFCM表面出现了带有羟基（-OH）的新物质，这些物质是去除磷酸盐的官能团。RFCM去除磷酸盐的机理推测为物理吸附、化学吸附和化学沉淀相结合，主要依靠配体交换和化学反应。该研究将为铝土矿渣在环境修复中的潜在应用提供参考。