Preparation of Ultra-High Purity Rare Earth Fluorides by Deep Deoxygenation of Liquid HF
FU Jie1, SONG Yulong1, TANG Rui1, QIAN Yuan1, SONG Nan2
1. Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800, China;
2. East China University of Science and Technology, Shanghai 200237, China
Abstract：Ultra-high purity rare earth fluorides (REF3) are critical candidate materials for high-performance laser optical fibers. However, the inherent problem of high oxygen content severely restricts their practical application in the optical fiber field. Deep deoxygenation of REF3 remains a critical technical challenge that urgently needs to be resolved. In this paper, liquid HF was proposed as a fluorination-extraction agent, and an innovative integrated process consisting of "wet chemical synthesis, deep deoxygenation with liquid HF, and high-temperature vacuum desorption of residual HF" was established for the deep purification of REF3 prepared by wet methods. Two approaches for eliminating bound HF, namely atmospheric evaporation and high-vacuum stripping, were systematically compared and characterized. Experimental results demonstrate that treatment at 500 ℃ under a vacuum of 0.01 Pa enables thorough elimination of oxygen-bearing impurities and trapped HF within REF?. Consequently, ultra-high purity lanthanum fluoride and yttrium fluoride were obtained, with an average total oxygen impurity content lower than 50 μg/g.
. Preparation of Ultra-High Purity Rare Earth Fluorides by Deep Deoxygenation of Liquid HF[J]. Chemical Reaction Engineering and Technology, 2026, 42(3): 244-249.
