The Hunter process is predominantly used to manufacture high-purity Ta powder. Among the various physical properties of the Ta powder, its impurity content is particularly crucial. In this study, the process temperature at which a liquid pool of raw material and diluent can be formed and the corresponding amount of diluent were analyzed by performing thermodynamic simulations using FactSage and HSC Chemistry software. Based on the results of the thermodynamic simulations, Ta powder was prepared at process temperatures of 700–800 °C and a specific amount of NaCl at each temperature. Thereafter, the prepared Ta powder was recovered and a post-treatment process was performed to ensure purity. The characteristics of the recovered Ta powder were evaluated according to each process condition by oxygen/nitrogen/hydrogen analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy, glow discharge-mass spectrometry, and X-ray diffractometry. The synthesized Ta powders were confirmed to exhibit purities >99.95% and oxygen, nitrogen, and hydrogen concentrations of 447, 21, and 10 ppm, respectively. The characterization results indicated that the produced Ta powders were fabricated entirely in a single phase with high purity and recovery rates. Finally, process optimization was achieved for manufacturing high-purity (≥3 N5) Ta powder with controllable impurities.
|Journal||International Journal of Refractory Metals and Hard Materials|
|Publication status||Published - 2023 Apr|
Bibliographical noteFunding Information:
This study was funded by the Korea Institute of Energy Technology Evaluation and Planning (No. 20195210100070 , development of upcycling technology for low-grade tantalum waste resources using dry and wet integrated processes) and funded by an internal R&D program(Development of material preparation/ surface treatment/ post-processing for molten metal based hard-facing technology with higher than 40 HRC harness) of the Korea Institute of Industrial Technology (KITECH) funded by the Ministry of Strategy and Finance, Republic of Korea.
- Hunter process
- Potassium heptafluorotantalate
- Reduction temperature
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry