Metallothermic reduction as an electronically mediated reaction

@article{Okabe1998MetallothermicRA,
  title={Metallothermic reduction as an electronically mediated reaction},
  author={Toru H. Okabe and Donald R. Sadoway},
  journal={Journal of Materials Research},
  year={1998},
  volume={13},
  pages={3372-3377}
}
The commonly held view that metallothermic reduction is strictly a chemical reaction and that the process is rate limited by mass transfer has been found to be incomplete. In a study of the production of tantalum powder by the reaction of K 2 TaF 7 with sodium, it has been shown that there are two dominant kinetic pathways, both involving electron transfer. Furthermore, the overall rate of reaction is limited by electron transport between the reactants. This indicates that metallothermic… 

Figures and Tables from this paper

Fundamentals of thermochemical reduction of TiCl4
Metallothermic reduction of TiO2
  • T. Okabe
  • Materials Science, Chemistry
  • 2020
Synthesis of nanoscale particles of Ta and Nb 3 Al by homogeneous reduction in liquid ammonia
The analysis of metallothermic reduction as an electronically mediated reaction predicted that the particle size of solid product could be reduced if the reaction were conducted in a medium that is a
Solid state reactions: an electrochemical approach in molten salts
Solid state reactions play crucial roles in highly efficient electrochemical energy conversion and storage devices, typically lithium ion batteries and ruthenium oxide supercapacitors. Electrolytic
Semi-Continuous Production of Tantalum Powder by Electronically Mediated Reaction (EMR)
An electronically mediated reaction (EMR) has been explored to produce tantalum powder semi-continuously by the calciothermic reduction of tantalum chloride (TaCl 5 ). TaCl 5 feedstock and reductant
Emerging molten salt technologies for metals production
  • D. Fray
  • Chemistry, Materials Science
  • 2001
Molten salts have been used in metal extraction for more than a century, and chemists and metallurgists have extensively studied the properties of these high-temperature phases. Because fundamental
Reduction of TiO2 in molten CaCl2 by Ca deposited during CaO electrolysis
Fundamental experiment; are conducted to confirm the calcium reactivity with titanium oxide in the molten calcium chloride. The TiO 2 samples placed in the molten salt could be reduced without any
...
...

References

SHOWING 1-10 OF 17 REFERENCES
Electrodeposition of Tantalum in NaCl ‐ KCl ‐ K 2TaF7 Melts
Electroreduction of dissolved in at 720°C was investigated by transient electrochemical techniques. The primary reaction involves a single reversible five electron step . In addition to the metal
Electrochemical Studies of Tantalum in Fluorochloroaluminate Melts at 200–450°C
The electrochemistry of tantalum (V) species in sodium fluorochloroaluminate melts (10 mole percent NaF) has been investigated in the temperature range of 200 to 450 C using cyclic, normal pulse, and
Electronic absorption spectra of reduction products of pentavalent niobium and tantalum in different alkali chloride and oxychloride melts
We have studied the electronic absorption spectra of niobium chloride and oxychloride compounds in different oxidation states and of the reduction products of pentavalent niobium and tantalum in
ANWENDUNGSMOGLICHKEITEN DES UMKEHRSTROMVERFAHRENS IN DER SCHMELZFLUSSGEWINNUNGSELEKTROLYSE. TEIL I
Tantalum electrolysis is chosen as an example to investigate the application of periodic current reversal in fused salt electrowinning. Part I of this study deals with the electrode processes in
Molten salt chemistry : an introduction and selected applications
The Structure of Molten Salts.- Thermodynamic Properties of Molten Salt Solutions.- On the Conformal Ionic Solution Theory-Principles and Applications.- Thermodynamics of Molten Salt Mixtures.-
The Production of Ductile Titanium
Formation of corrosion-resistant layers by electrodeposition of refractory metals or by alloy electrowinning in molten fluorides
The electrolytic treatment of less resistant metals such as iron, copper and nickel with tantalum or niobium has been carried out in K2TaF7-LiF-NaF or K2NbF7-LiF-NaF solutions in the 550 to 1050°C
...
...