Work

Dense Molten Salt Method for Large-Scale Synthesis of Rare Earth Hafnate Powders

Year: 2026

Type: article

Abstract: Rare earth hafnates (RE2Hf2O7; RE = La, Gd, Nd, Eu, etc.) with low thermal conductivity and excellent high-temperature stability are indispensable key materials in extreme environments and high-tech fields. In this work, a dense molten salt method (DMS) was developed for mass preparation of hafnate powders including La2Hf2O7, Nd2Hf2O7, Gd2Hf2O7, Eu2Hf2O7, and even (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Hf2O7, which only allowed the trace salt volatilization, while the internal salt “micro-pools” significantly promoted the in-situ formation of target products at relatively lower temperatures. Using La2Hf2O7 as an example, it could be successfully prepared at 1100 °C with 1:1 mass ratio of salt to reactant, both of which are much lower than those of traditional “powdery” molten salt method. Furthermore, only ~6 wt.% of salt loss was detected in current dense route, while it was as high as ~80 wt.% in the traditional one. A large-scale synthesis of RE2Hf2O7 powder by DMS may be achievable by stacking these dense blocks in a tunnel kiln, suggesting its potential applicability and scalability toward industrial production.

Source: Materials

DOI: 10.3390/ma19091765

Authors: Zhijun Xiao, Yongxin Wang, Jingjie Li, Zhong Huang, Yu Zhang, Shaowei Zhang

Institutions: Wuhan University of Science and Technology, Shanxi Institute of Technology, University of Exeter

Language: English

Topic: Molten salt chemistry and electrochemical processes

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funders: National Natural Science Foundation of China, Wuhan University, Wuhan University of Science and Technology