Generated compounds at the V-slag/CaO diffusion surface and diffusion characteristics of V and Ca in calcium vanadate.

Author(s) Yue, H.R.; Xue, X.X.
Journal J Hazard Mater
Date Published 2020 Feb 22
Abstract

Vanadium slag/CaO diffusion couples were prepared to study the diffusion characteristics of the vanadium slag/CaO interface at 1083 K in the air. The generated phases at different regions were characterized by EPMA, EDS, XRD, and element maps analysis. At the vanadium slag surface that the diffused Ca dose not reached, the main generated phases were MnO and FeO. V was oxidized to V and reacted with the Ca to form a small amount of CaVO. Cr was at a disadvantage compared with V in occupying the original Ca of the slag. At the vanadium slag surface that the diffused Ca had reached, the main generated phases were CaVO. At the CaO surface, the main generated phases were CaVO and CaVO. The interdiffusion coefficients were calculated by a new approach that modified from the Boltzmann-Matano method including the determination of the Matano surface, calculation of the integral and differential using the raw data of the concentration profiles. As the molar fraction of Ca was in the range of 0.15 to 0.86, the average interdiffusion coefficient of Ca was 2.54 × 10 cm·s. The average interdiffusion coefficient of V at the V molar fraction of 0.001 to 0.43 was 1.96 × 10 cm·s.

DOI 10.1016/j.jhazmat.2020.122368
ISSN 1873-3336
Citation Yue H-, Xue X-. Generated compounds at the V-slag/CaO diffusion surface and diffusion characteristics of V and Ca in calcium vanadate. J Hazard Mater. 2020;393:122368.

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