On the Electrochemical Reduction Mechanism of CaWO4 to W Powder

Erdogan, Metehan
Karakaya, İshak
The reduction mechanism of CaWO4 to W in molten eutectic CaCl2-NaCl electrolyte has been studied. Cyclic voltammetry and constant potential electrolysis tests were performed to determine the reversible cell potential. Analyses of the experimental results revealed that at least 2.2 V was required to compensate the potentials for the accompanying cell reaction and the electrode polarizations. A cell reaction was proposed by associating the experimental results and the Gibbs energy changes of the possible reactions.


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Salamova, UR; Masimov, AA; Ozer, M (1996-05-01)
The dependences of the refractive indices of aqueous solutions of dextran (D), poly(ethylene glycol) (PEG), and poly(vinyl pyrrolidone) (PVP), and D-PEG and D-PVP mixtures, on the polymer concentration has been investigated in order to study structural and conformational changes as a function of the increasing polymer concentration. It is shown that in contrast to solutions of single polymers, conformational changes are not observed in aqueous solutions of mixed polymers, even at high concentrations, and th...
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Aksu, Ceren; Sanin, Faika Dilek; Gültekin, Güzin Candan; Department of Biotechnology (2010)
Nutrients and cations have significant effect on activated sludge characteristics and therefore effect the efficiency of whole processes. To determine the properties in phosphorus deficient medium and the effect of calcium ions two reactor sets with two different phosphorus concentration (C/N/P=100/5/0.05 and C/N/P=100/5/1), three different concentrations of calcium (0.5, 5, 15 meq/L) were operated with 8 days of sludge residence time and an effective volume of 2 L. Results showed amount and composition of ...
A squaraine-based sodium selective fluorescent chemosensor
Oguz, U; Akkaya, EU (1998-08-06)
A novel squaraine with a lariat-crown ether cation-receptor unit was synthesized and shown to selectively respond to Na+ ions in polar protic solvents. The selectivity of the novel ligand, together with the impressive spectroscopic properties of squaraines yields a promising chemosensor,
TOSUN, I; Yılmaz, Levent (Wiley, 1982-01-01)
Fickian diffusion of organic penetrants in glassy polymers is formulated as a moving‐boundary problem, and the effect of concentration‐dependent diffusivity on the concentration distribution is investigated. The solutions obtained for concentration‐dependent and constant diffusivity cases are compared. The results show that the concentration distribution curves differ both quantitatively and qualitatively. It is concluded that the sharp advancing boundary between the glassy and rubbery regions is due not on...
Effects of additives on mechanical milling and hydrogenation of magnesium powders
Guvendiren, M; Bayboru, E; Öztürk, Tayfur (2004-04-01)
A study is carried out on the role of additives for structural refinement of magnesium powders in mechanical milling. Additives, namely Al2O3, SiC, V and graphite are chosen so as to cover a wide hardness range. Structural refinement after milling is studied both metallographically and in terms of X-ray line broadening. It is found that for efficient structural refinement, the additives should be chosen not on the basis of their hardness but rather whether or not they are preserved with an acceptable size d...
Citation Formats
M. Erdogan and İ. Karakaya, “On the Electrochemical Reduction Mechanism of CaWO4 to W Powder,” METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE, pp. 667–670, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40411.