Effective adsorption and recovery of rare earth elements from wastewater by activated talc

The extraction process of ion-type rare earth mines generates a significant amount of wastewater containing rare earth elements (REE) with low concentration. It is of great significance to recover REE from the wastewater in order to reduce environmental toxicity and improve the utilization efficiency of rare earth mining. We propose a strategy to enhance the adsorption and enrichment of REE in wastewater by mechanically activating talc, which exposes the hydroxyl groups within the double layered hydroxide to the surface. The effects of various factors, including ball milling time, milling speed, initial pH and initial concentration on rare earth adsorption were investigated. Additionally, the adsorption mechanism of the process was studied by exploring conditions of reaction temperature, reaction time and dosage. The results demonstrated that the adsorption of REE onto the activated talc followed Langmuir isotherm model. At 318.15 K, the maximum adsorption capacity could reach 64.09 mg·g−1. These findings highlight the simple and cost-effective recovery of REE from wastewater, offering significant potential for widespread application in the treatment of rare earth industrial wastewater. [Display omitted] •A simple method was developed to economically and efficiently prepare active talc.•The abundant hydroxyl groups inside the talc are exposed for adsorption of rare earth ions.•The prepared active talc can efficiently adsorb and recover rare earth ions in actual wastewater.