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The rate of selenium removal from tellurium by hydrogen purging
Author(s) -
Rawling J. R.,
Toguri J. M.
Publication year - 1969
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450470216
Subject(s) - selenium , tellurium , selenide , chemistry , hydrogen , thermal diffusivity , diffusion , analytical chemistry (journal) , mass transfer , kinetics , inorganic chemistry , radiochemistry , thermodynamics , chromatography , organic chemistry , physics , quantum mechanics
The reaction between hydrogen gas and selenium dissolved in liquid tellurium is described as follows H 2 (g) + Se ⇄ H 2 Se(g) The kinetics of this reaction have been investigated at temperatures ranging between 525 and 625°C and at concentrations of selenium varying between 250 and 3,300 ppm. Under all conditions investigated the reaction was controlled by transport processes in one or other of the two phases depending on the relative values of the mass transfer coefficients. Subject to the assumption that the solution of selenium in tellurium is an ideal one the molecular diffusion coefficient of mixtures of hydrogen selenide in hydrogen, Dg , is approximately 1.6 cm. 2 sec. −1 at 525°C, and 2.1 cm. 2 sec. −1 at 625°C. In view of complicating factors accurate values of the diffusivity of selenium in liquid tellurium cannot be deducted from the experimental results. However, the value obtained from experimental measurements of 7.59 × 10 −4 cm. 2 sec. −1 at 525° is in reasonable agreement with the value of 9.85 × 10 −5 cm. 2 sec. −1 reported in the literature.