scholarly journals Electrochemical Dissolution Process of Tungsten Carbide in Low Temperature Molten Salt System

Author(s):  
Xuehua Wang ◽  
Liwen Zhang ◽  
Xiaoli Xi ◽  
Zuoren Nie

Abstract Tungsten was extracted from LiCl-KCl-Li2WO4 molten salt with tungsten carbide as soluble anode, and its electrochemical dissolution was studied. Although the fused salt electrochemical method has the advantages of short process and easy operation of the equipment, there are some problems in the current electrolysis process, such as higher electrolysis temperature, high energy consumption and complex composition of the products, in order to reduce the electrolysis temperature and energy consumption, tungsten was extracted by LiCl-KCl-Li2WO4 molten salt system at 400-600°C. In addition, compared with the blank salt electrolysis, the addition of Li2WO4 as the active material makes the reaction more likely to occur, and improves the dissolution efficiency and the current efficiency. Through a series of electrochemical tests, it is proved that adding Li2WO4 decreases the charge transfer resistance, speeds up the reaction and studies the oxidation-reduction process of tungsten ion in tungstate, it is proved that the redox process is a reversible process controlled by diffusion. Clusters of spherical tungsten powders were prepared at 500℃ by changing the experimental parameters to obtain the optimal conditions.

2021 ◽  
Vol 1026 ◽  
pp. 39-48
Author(s):  
Han Bing He ◽  
Yu Si Wang ◽  
Ze Xiang Luo ◽  
Jing Zeng

The effect of different additives Ni, Fe, Cu on the structure and properties of electrolyte system 78% Na3AlF6- -9.5%AlF3-5.0%CaF2-7.5%Al2O3 at 1200K and 1.01Mpa was studied by molecular dynamics method. The radial distribution function, coordination number, diffusion coefficient, conductivity, and viscosity of the system were discussed in detail. The results demonstrated that the order of the self-diffusion coefficient of ions in the electrolyte system is: Na+ > F- > O2- > Ca2+ >Al3+. The addition of Ni and Fe connected the free aluminum composite ion groups in the system through fluorine bridges, which enhanced the interaction between Al3+ and Al3+. The addition of Cu weakened the interaction between Al3 + and Al3+ and the F-. The interaction between Al3+ and Na+, [AlF7]4- ionic groups might appeared in the melt system. After adding NiO, Fe2O3, and Cu, the electrical conductivity of the system increased, and the viscosity decreased. The research work revealed the influence of Ni, Fe, Cu on the ion existence form, mobility, inter-ion interaction and diffusion mechanism of cryolite molten salt system, which has important guiding significance for aluminum electrolysis production.


2019 ◽  
Vol 730 ◽  
pp. 587-593 ◽  
Author(s):  
Hui Guo ◽  
Jie Li ◽  
Hongliang Zhang ◽  
Tianshuang Li ◽  
Jiawei Luo ◽  
...  

2014 ◽  
Vol 908 ◽  
pp. 159-162
Author(s):  
Jie Li ◽  
Yang Pei ◽  
Ya Bin Liu ◽  
Yun Gang Li

The liquidus temperature of molten salt NaCl-KCl-Na3WO3F3 system was measured by differential thermal analysis. The results show that in the molten salt system when XNaCl:XKCl=1:1, XNa3WO3F3<0.6 the liquidus temperature decreased with increase of Na3WO3F3 content; when XNaCl:XKCl=1:1, XNa3WO3F3> 0.6 the liquidus temperature increased with the increase of Na3WO3F3 content; the eutectic temperature is 612.9 °C, the eutectic composition is XNaCl=0.2, XKCl=0.2, XNa3WO3F3=0.6.


1995 ◽  
Author(s):  
J. E. Sisolak ◽  
M. T. Truebenbach ◽  
D. L. Henderson

1995 ◽  
Vol 262 ◽  
pp. 45-54 ◽  
Author(s):  
P. Peretz ◽  
G. Hatem ◽  
M. Gaune-Escard ◽  
M. Hoch

1976 ◽  
Vol 29 (9) ◽  
pp. 2069
Author(s):  
RG Anthony ◽  
H Bloom

Activities of PbCl2 in the molten system K2SO4+PbCl2 have been measured at 1012 K by a transpiration vapour pressure method. Values of PbCl2 activities are calculated from the conformal ionic solution model (CIS), the result being in reasonable agreement with experimentally measured values. Results obtained may therefore be summarized by the CIS equation APbCl2 = xpb(xcl)2exp[0.2405/T)(X?k)2{-3285-X?pb(11564+2032(3X?k-1))}] where Xi, X?t are ion fractions and equivalent ion fractions respectively.


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