Analysis of Hazardous Characteristics of Electrolyte Crust During Electrolytic Extraction of Rare Earth Element Neodymium

Molten salt electrolysis is the primary industrial method for neodymium production, generating large volumes electrolyte crust after prolonged operation. However, the hazardous characteristics and environmental risks of this crust remain insufficiently characterized, which may hinder its proper environmental management and resource recovery. This study systematically analyzed the elemental composition, organic residues, and hazardous characteristics of electrolyte crust using XRF, XRD, XPS, and GC-MS, supplemented by standardized tests conducted in accordance with Chinese national standards GB 5085.1, GB 5085.3–GB 5085.6-2007 and HJ 298-2019. No VOC or SVOC residues were detected. Hazard characteristic tests confirmed that the electrolyte crust did not exhibit ignitability, corrosivity, reactivity, leaching toxicity or other tested hazardous characteristics. The calculated acute toxicity estimate (ATE) did not indicate a significant acute toxicity potential. These findings provide experimental and theoretical support for the environment risk evaluation and resource recovery of rare earth electrolytic solid wastes.