Abstract:Rare earth is an indispensable strategic resource in China, which is widely used in high-tech fields such as aerospace, military defense and new rare earth materials. However, in the process of mining and using rare earth resources, a large amount of low-concentration rare earth wastewater will inevitably be generated, which will cause a waste of rare earth resources while polluting the water body. To solve this problem, a magnetic composite adsorbent Fe3O4@PANI was prepared by combining magnetic nano-Fe3O4 and polyaniline (PANI), and the low-concentration rare earth ions were enriched and recovered by adsorption. The results show that the outer layer of polyaniline effectively encapsulates the internal Fe3O4 core and provides effective protection for it in the environment of low pH value, so that the adsorption performance of the Fe3O4@PANI on Ho(Ⅲ) ions is significantly improved compared with Fe3O4, and the saturated adsorption capacity of Fe3O4@PANI can reach 145.48 mg/g, and the adsorption process conforms to the Freundlich model, the adsorption rate is still 82.77% after three cycles. The material has good potential for enrichment of rare earth ions.